Title of Invention	LUBRICATING LIQUID SEPARATOR
Abstract	ABSTIL-VCT OF THE DISCLOSUKE A lubricating liquid separator is disclosed whicii can damp a compressor pulsation noise effectively and impTove the lubricating liquid separating performance without greatly enlarging the size of the separator itself. A demister (6) having a sound absorbing performance is disposed on an outer periphery side of a partition plate (5). Compressed gas which enters the interior of a housing (2) through a compressed gas inlet port (3) flows as rotating flow in a flow path (lO) formed between the partition plate (5) and a portion of a side wall of the housing (2) opposed to the partition plate (5). Pressure pulsation of the compressed gas is diminished by the demister (6), and a compressor pulsation noise induced by the rotating flow of the compressed gas is diminished by the sound absorbing performance of the demister (6). Further, with the demister (G), reflection of the compressed gas at a wall surface of the partition plate (5) is suppressed, and scattering of lubricatiug hquid separated from the compressed gas is suppressed. Selected drawing"- Fig. 1

Title of Invention

LUBRICATING LIQUID SEPARATOR

Abstract

ABSTIL-VCT OF THE DISCLOSUKE A lubricating liquid separator is disclosed whicii can damp a compressor pulsation noise effectively and impTove the lubricating liquid separating performance without greatly enlarging the size of the separator itself. A demister (6) having a sound absorbing performance is disposed on an outer periphery side of a partition plate (5). Compressed gas which enters the interior of a housing (2) through a compressed gas inlet port (3) flows as rotating flow in a flow path (lO) formed between the partition plate (5) and a portion of a side wall of the housing (2) opposed to the partition plate (5). Pressure pulsation of the compressed gas is diminished by the demister (6), and a compressor pulsation noise induced by the rotating flow of the compressed gas is diminished by the sound absorbing performance of the demister (6). Further, with the demister (G), reflection of the compressed gas at a wall surface of the partition plate (5) is suppressed, and scattering of lubricatiug hquid separated from the compressed gas is suppressed. Selected drawing"- Fig. 1

Full Text	TITLE OF THE IN\:EXnON LUBRICATING LIQUID SEPARATOR BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating liquid separator for separating and recovering lubricating liquid from compressed gas, the lubricating Hquid being used, for example, in an oil-cooled air compressor, a freezer, a gas compressor or a water lubrication type air compressor. 2. Description of the Related Art In screw type or scroll type air/gas compressors or freezers there is used such liquid as oil or water as both lubricant and rotor coolant for rotors in a compressing section, the rotors being in contact with each other. In these gas compressors, compressed gas is discharged in a mixed state with lubricating hquid, and therefore a lubricating Hquid separator for separating and recovering lubricating liquid from the compressed gas is installed in each of the gas compressors. The lubricating Hquid separator is called an oil recovering device or an oil separator in case of the lubricating liquid being oil. And the lubricating hquid separator is called a water recovering device or a water separator in case of the lubricating liquid being water. According to the principle of the lubricating hquid separator, compressed gas is introduced so as to flow along the circumferential direction from a side surface of a cylindrical housing, and there is produced rotating flow of the compressed 1 gas along an inner -i\-all surface of the housing. By ihe resulting centrifugation effect, the lubricating liquid component is gathered on the inner wall surface of the housing for separation from the gaseous component. The compressed gas freed from the lubricating liquid to a certain extent by the centrifugation effect is discharged from the lubricating- hquid separator. At this time, the remaining lubricating liquid is usually removed by a metalhc or fibrous lubricating liquid removing filter called demister. The demister is known to exhibit a predetermined sound absorbing performance. In order to let the centrifugation effect be exhibited to a satisfactory extent, the longer the rotating flow created along the inner wall surface of the housing of the lubricating liquid separator, the better. Therefore, a compressed gas inlet port for introducing the compressed gas into the lubricating liquid separator is generally formed on an upper side of the housing of the lubricating liquid separator. However, since the precipitated lubricating Hquid stays in a lower portion of the housing, a compressed gas discharge port for discharging the compressed gas from the lubricating Hquid separator after separation of the lubricating Hquid is also formed on the upper side of the housing. In view of this point, a cylindrical partition plate having a predetermined length in the vertical direction and which surrounds the compressed gas discharge port is in many cases instaUed within the housing, lest the compressed gas entering from the compressed gas inlet port and containing the lubricating Hquid, and the compressed gas after separation of the lubricating oil and discharged from the compressed gas discharge port should mix each other. 2 In Patent Literature 1 there is disclosed a separator wherein a demister is disposed inside a partition plate. On the other hand, there also is a case where a demister is disposed so as to divide the interior of the housing into two vertically without using a partition plate. [Patent Literature l] Japanese Patent Laid-Open Publication No. Sho 47 (l972)-26749 However, in the separator of Patent Literature 1, a compressor pulsation noise is generated within the housing as a result of entry of compressed gas involving pressure pulsation into the housing. Consequently, the separator itself acts as a noise source, contributing greatly to an increase of noise in a gas compressor or the Hte. In this connection, in Patent Literature 2 is disclosed an oil separator in an oil-cooled compressor wherein a noise damping section is provided in the interior of a vessel to reduce noise, the noise damping section having a casing which encloses a vessel-iaside opening of a gas inlet section and also having a gas-permeable, heat-resistant, sound-absorbing material layer disposed at a position opposed to the opening. In Patent Literature 3 is disclosed an oil separator wherein a member for inducing a pressure loss is disposed near a tip of a coolant inlet pipe, allowing oil contained in a mixed fluid to be adsorbed to the member, and the flow velocity of the mixed fluid is adjusted appropriately by the member, thereby suppressing noise generated upon collision of fluid with an inner wall of a vessel body. Further, in Patent Literature 4 is disclosed an oil separator wherein a sound absorbiug material is disposed at a position lower than a gas inlet 3 port in the interior of a vessel not having a partition plate and at a position at least an upper surface of the sound absorbing material is not soaked into oil stored in an oil sump, thereby reducing generated noise. This oil separator is superior in oil separating performance and does not deteriorate the operation efficiency of the associated compressor. In this oil separator, there is disposed a demister so as to divide the interior of the vessel body into two vertically. [Patent Literature 2] Japanese Patent LaidOpen Publication No. Hei 8 (1996)-128388 [Patent Literature 3] Japanese Patent Laid-Open Publication No. 200598534 [Patent Literature 4] Japanese Patent Laid-Open Publication No. 2007-327439 The demister exhibits a sound absorbing performance to a certain extent, but even if the demister is disposed as in Patent Literatures 1 and 4, there is obtained httle noise damping effect. Even if the demister is disposed outside a lubricating liquid separator, there will be obtained no noise damping effect, because the demister is not designed as a noise damper. In the oU separator of an oil-cooled compressor disclosed in Patent Literature 2, an increase in the number of parts resxilts from provision of the noise damping section within the vessel, thus giving rise to the problem of increase in cost. In the oil separator disclosed in Patent Literature 3, some improvement is needed so that the pressure loss inducing member disposed near the tip of the coolant inlet pipe may not be scattered by the discharge 4 gas of a high pressure. In. the oil sepai'ator disclosed in Patent Literature 4, because the partition plate is not provided, scattering of the lubricating liquid after separation from the compressed gas which enters the interior of the housing is conspicuous, thus giving rise to the problem that the separation efficiency becomes lower. Moreover, in the lubricating liquid separator which utilizes the centrifugation effect, it is necessary to enlarge the vertical length of the housing in order to enhance the separation efficiency. As a result, not only the cost of the lubricating liquid separator itself increases, but also there arises the problem of space when disposing the associated compressor body and the lubricating hquid separator within a single package. Further, as disclosed in Patent Literature 1, if a demister is disposed inside a partition plate, there arises the problem of lowering in efGciency of the gas compressor due to an increase of pressure loss. On the other hand, if there is formed such a flow path as extends through a demister, it wdl be impossible to expect the demister to exhibit any noise damping effect; besides, the demister cannot play its original role. SUMMARY OF THE INVENTION It is an object of the present invention to provide a lubricating hquid separator capable of damping a compressor pulsation noise effectively and improving the lubricating liquid separating performance without greatly enlarging the size of the separator itself. According to the present invention, there is provided a lubricating 5 liquid separator for separating and recoverLag lubricating liquid from compressed gas containing the lubricating liquid by creating rotating flow of the compressed gas, the lubricating liquid separator comprising a hollow housing; a compressed gas inlet port formed in a side wall of the housing and through which the compressed gas containing the lubricating liquid passes when flowing into the housing; a compressed gas discharge port formed in an upper wall of the housing and through which the compressed gas after separation of the lubricating liquid passes when discharged from the interior of the housing; a partition plate disposed in the interior of the housing and having a predetermined length in the vertical direction, the partition plate being connected to the upper wall of the housing and enclosing the compressed gas discharge port; and a lubricating liquid removing filter disposed on an outer surface side of the partition plate or on a portion of the side wall opposed to the partition plate, the lubricating liquid removing filter having a sound absorbing performance and functioning to remove the lubricating liquid from the compressed gas containing the lubricating liquid. According to the above structure, the lubricating liquid removing filter for removing the lubricating liquid firom the compressed gas which enters the interior of the housing through the compressed gas inlet port is disposed on the outer surface side of the partition plate or on the portion of side wall of the housing opposed to the partition plate. Consequently, pressure pulsation of the compressed gas which enters the interior of the housing and which flows as rotating flow in a flow path formed between the partition plate and the portion of side wall opposed to the partition plate is diminished by the lubricating liquid removing filter, and a compressor 6 pulsation noise caused by the rotating flow of the compressed gas in the flow path is diminished by the sound absorbing perfoimance of the lubricating liquid removing filter. Besides, with the lubricating Hquid removing filter, reflection of the compressed gas at the wall surfaces of the housing and the partition plate is suppressed, and scattering of the lubricating Kquid separated from the compressed gas is suppressed thereby, so that the rotating flow of the compressed gas become smooth and the lubricating liquid separating performance is improved. Consequently, it is possible to damp the compressor pulsation noise effectively and improve the separation performance without greatly enlarging the size of the separator itself. In the lubricating liquid separator of the present invention, the lubricating hquid removing filter may be disposed on each of the outer surface side of the partition plate and the portion of side wall opposed to the partition plate. According to this structure, since the lubricating liquid removing filter is disposed on both the outer surface side of the partition plate and the portion of side wall of the housing opposed to the partition plate, pressure pulsation of the compressed gas which flows as rotating flow in the flow path formed between the partition plate and the portion of side wall opposed to the partition plate can be further diminished. Besides, the compressor pulsation noise caused by the rotating flow of the compressed gas in the flow path can be further diminished by the sound absorbing performance of the lubricating liquid removing filter. Moreover, with the lubricating liquid removing filter, reflection of the compressed gas at the wall surfaces of the housing and the partition plate is further suppressed, and scattering of the lubricating hquid separated &om the compressed gas is 7 further suppressed, so that the rotatang flow of rhe compressed gas can be made smoother, and the lubricating liquid separating performance can be further improved. In the lubricating liquid separator of the present invention, the lubricating liquid removing filter may be disposed on the portion of side wall opposed to the partition plate and a lower end of the lubricating hquid removing filter may be positioned at a height equal to or lower than a lower end of the partition plate. According to this structure, since the lower end of the lubricating Uquid removing filter disposed on the portion of side wall of the housing opposed to the partition plate is positioned at a height equal to or lower than the lower end of the partition plate, pressitre pulsation of the compressed gas which flows as rotating flow in the flow path formed between the partition plate and the portion of side wall opposed to the partition plate can be suitably diminished in the area from the compressed gas inlet port to a lower end of the flow path. Besides, a compressor pulsation noise caused by the rotating flow of the compressed gas in the Hov.' path can be diminished thoroughly in the area fiora the compressed gas inlet port to the lower end of the flow path. Moreover, with the lubricating Mquid removing filter, reflection of the compressed gas at the housing wall surface is suitably suppressed in the area from the compressed gas inlet port to the lower end of the flow path and scattering of the lubricating liquid separated from the compressed gas is thereby suppressed to a satisfactory extent. Therefore, the rotating flow of the compressed gas can be made smoother and it is possible to further improve the lubricating liquid separating performance. 8 BREIF DESCRIPTION OF THE DRAV\1NGS Fig. lAis a sectional view of a lubricating liquid separator according to an embodiment of the present invention, and Fig. IB is a sectional view taken on line A-Ain Fig. \A', Fig. 2 is a graph showing experimental results; Fig. 3A is a sectional view of a lubricating oil separator according to another embodiment of the present invention, and Fig. 3B is a sectional view taken on line A-A in Fig. 3A; Fig. 4Ais a sectional view of a lubricating liquid sepai'ator according to a further emhodiment of the present invention, and Fig. 4B is a sectional view taken on line A-A in Fig. 4 A; and Fig. 5Ais a sectional view taken online A-Ain Fig. lA, and Fig. 5B is a sectional view taken on line A-A in Fig. 3A. DESCRIPTION OF THE PREFERRED EMBODIMENTS Lubricating liquid separators embodying the present invention will be described below with reference to the accompanying drawings. [First Embodiment] A lubricating liquid separator 1 according to a first embodiment of the present invention wiU be described below with reference to Fig. 1. (Structure of the lubricating Hquid separator l) The lubricating liquid separator 1 constitutes a part of a gas compressor together with a compressor body (not shown). As shown in Fig. 1, the lubricating hquid separator 1 has a cylindrical housing 2 made of metal or resin having pressure resistance. The housing 2 is installed in a 9 vertically (longitudinally^ upright state. The shape of the housing 2 is nor limited to the cyhndrical shape, but may be an elliptic shape or a polygonal prism shape. The housing 2 has a compressed gas inlet port 3 formed in a side wall thereof. Further, a lubricating oil sump portion 8 is formed at an inside bottom of the housing 2. The compressed gas inlet port 3 is connected through a gas inlet pipe 9 to a discharge port (not shown) of a compressor body. Compressed gas compressed by the compressor body and containing lubricating hquid passes through the compressed gas inlet port 3 and enters the interior of the housing 2. As shown in Fig. IB which is a sectional view taken on hne A-A in Fig. lA, the compressed gas inlet port 3 is foimed so as to be parallel to a tangent to the peripheral surface of the cylindrical housing 2. Consequently, the compressed gas which passes through the compressed gas inlet port 3 flows from a side face portion of the housing 2 into the housing 2 along the circumferential direction, resulting in creation of rotating flow of the compressed gas along the inner wall suiface of the housing 2. With this rotating flow, a centrifugation effect (cyclone effect) is induced tn the compressed gas. As shown in Fig. lA. the compressed gas inlet port 3 is located at an upper position in the longitudinal direction of the housing 2. As a result, the rotating flow of the compressed gas becomes longer and the centrifugation effect for separating the lubricating hquid is exhibited to a satisfactory extent. Moreover, a compressed gas discharge port 4 is formed in a top wall of the housing 2, through which the compressed gas separated from the lubricating liquid is discharged. The compressed gas discharged from the 10 compressed gas discharge port 4 is conveyed to the nexr process. In the interior of the housing 2 is disposed a cylindrical partition plate 5 having a predetermined length in the vertical direction, connected to the top wall of the housing 2 and enclosing the compressed gas dischai-ge port 4. A lower end of the partition plate 5 is positioned lower than the compressed gas inlet port 3. And the compressed gas inlet port 3 and the compressed gas discharge port 4 are consequently partitioned from each other by the partition plate 5, whereby the compressed gas entering from the compressed gas inlet port 3 and containing lubricating Hquid and the compressed gas dischai-ged from the compressed gas discharge port 4 and freed from the lubricating liquid are prevented from being mixed with each other. The shape of the partition plate 5 is not hmited to the cylindrical shape, but may be an elliptic shape or a polygonal prism shape. A lubricating liquid removing fdter (demister) 6 is mounted on an outer surface side of the partition plate 5 to remove lubricating liquid from the compressed gas which contains the lubricating liquid. The demister 6 is formed of a metaUic or resinous, fibrous, porous material, and has a sound absorbing performance. With the demister 6 thus mounted on the outer surface side of the partition plate 5, reflection of the compressed gas at the wall surface of the partition plate 5 is suppressed, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby. Besides, since the demister 6 does not obstruct the rotating flow of the compressed gas, there is no fear of lowering in ef&ciency of the gas compressor caused by increase of a pressure loss. A lower end of the demister 6 is positioned at a height equal to or 11 higher than the lower end of the partition plat^ 5. whereby the lubricatine liqxiid adhered to the demister 6 is prevented from being discharged fcom the compressed gas discharge port 4 together with the compressed gas after separation of lubricating liquid. The demister 6 may be disposed not on the outer surface side of the partition plate 5 but on the portion of side wall of the housing 2 opposed to the partition plate 5. As to this structure, a description will be given below in a second embodiment of the present invention. In a bottom wall of the housing 2, which is the bottom of the lubricating liquid sump portion 8, there is formed a lubricating liquid discharge port 7. The lubricating Kquid discharge port 7 is for recovering the lubricating liquid stored in the lubricating liquid sump portion 8. The lubricating liquid recovered from the lubricating liquid sump portion 8 is returned to the compressor body. (Operation of the lubricating hquid separator l) The following description is now provided about the operation of the lubricating Hquid separator 1. Since the compressed gas inlet port 3 and the compressed gas discharge port 4 are partitioned from each other by the partition plate 5, the lubricating hquid^containing compressed gas which enters the interior of the housing 2 from the compressor body through the compressed gas inlet port 3 passes through a flow path 10 formed between the demister 6 and a portion of the housing 2 opposed to the demister 6. Therefore, the lubricating liquid-containing" compressed gas which enters the interior of the housing 2 is never mixed with the compressed gas which is discharged from the 12 compressed gas discharge port 4 after separation of lubricaring Hquid. In the flow path 10, rotating flow along the inner wall surface of the cylindrical housing 3 is created in the compressed gas, whereby a centrifugation effect (cyclone effect) is developed in the compressed gas. As a result, lubricating liquid is separated from the compressed gas. In this connection, the compressed gas flowing as rotating flow in the flow path 10 strikes against the demister 6, whereby pressure pxdsation of the compressed gas is diminished. At the same time, a compressor pulsation noise caused by the rotating flow of the compressed gas is diminished by the sound absorbing performance of the demister G. The compressed gas freed from the lubricating liquid by the rotating flow passes through the demister 6, whereby the lubricating Uquid is further removed. In this case, with the demister 6, reflection of the compressed gas at the wall surface of the partition plate 5 is suppressed, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby. Consequently, the rotating flow of the compressed gas becomes smooth and the lubricating Uquid separating performance is improved. Moreover, since the demister 6 does not obstruct the rotating flow of the compressed gas, there is no fear of lowering in efficiency of the gas compressor caused by increase of a pressure loss. The lubricating hquid separated from the compressed gas adheres to an inner wall surface of the side wall of the housing 2. As a resiilt, droplets of the lubricating liquid grow on the waU surface, and the thus-grown droplets flow down along the wall surface of the housing 2 by their own weights, so that the lubricating liquid accumulates in the lubricating Hquid 13 sump portion 8. On the other hand, the compressed ^as after separation of the lubricating liquid is discharged from the compressed gas discharge port 4, and is conveyed to the next process. Thus, the demister 6 for removing the lubricating liquid firom the compressed gas which enters the interior of the housmg 2 through the compressed gas inlet port 3 is disposed on the outer surface side of the partition plate 5. Therefore, pressure pulsation of the compressed gas entering the interior of the housing 2 and flowing rotationaUy in the flow path 10 defined between the partition plate 5 and the portion of side wall of the housing 2 opposed to the partition plate 5 is diminished by the demister 6, and a compressor pulsation noise caused by the rotating flow of the compressed gas in the flow path 10 is diminished by the sound absorbing performance of the demister 6. Further, reflection of the compressed gas at the wall surface of the partition plate 5 is suppressed by the demister 6, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby, so that the rotating flow of the compressed gas becomes smooth and the lubricating hquid separating performance is improved. Consequently, it is possible to damp the compressor pulsation noise effectively and improve the lubricating liquid separating performance without greatly enlarging the size of the separator itself. (Experimental Results) Fig. 2 shows experimental results obtained by comparing a noise level at a 1 m-spaced position from a lubricating hquid separator of a conventional structure and, the noise level 1 m-spaced from the lubricating 14 hquid separator 1 of this embodiment. The convenuonal iubricamig hquid separator is of a structure not having the demister 6 in the lubricating hquid separator 1 shown in Fig. 1. From Fig. 2 it is seen that the provision of the demister 6 on the outer surface side of the partition plate 5 leads to lowering of the noise level. (Outline of this embodiment) In the lubricating liquid separator 1 of this embodiment, as described above, lubricating hquid is separated and recovered from compressed gas containing the lubricating hquid by creating rotating flow of the compressed gas. The lubricating separator 1 comprises a hollow housing 2, a compressed gas inlet port 3 formed in a side wall of the housing 2 and through which the compressed gas containing the lubricating hquid passes when flowing into the housing 2, a compressed gas discharge port 4 formed in a top wall of the housing 2 and through which the compressed gas after separation of the lubricating Hquid passes when discharged from the interior of the housing 2, a pai'titiou plate 5 disposed in the interior of the housing 2 and having a predetermined length in the vertical direction, the partition plate 5 being connected to the top wall of the bousing 2 and enclosing the compressed gas discharge port 4, and a lubricating Hqmd removing filter (demister 6) disposed on an outer surface side of the partition plate 5 or on a portion of the side wall of the housing 2 opposed to the partition plate 5, the lubricating hquid removing filter having a sound absorbing performance and functioning to remove the lubricating hquid from the compressed gas containing the luhricating liquid. According to this structure, the lubricating hquid removing filter for 15 removing lubricating liquid from the compressed gas which enters the mterior of the housing 2 through the compressed gas inlet port 3 is disposed on an outer surface side of the partition plate 5 or on the portion of side wall of the housing 2 opposed to the partition plate 5. Therefore, pressure pulsation of the compressed gas which enters the interior of the housing 2 and which flows as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side wall of the housing 2 opposed to the partition plate 5 is diminished by the lubricating hquid removing filter, and a compressor pulsation noise caused by the rotating flow of the compressed gas in the flow path 10 is diminished by the sound absorbing performance of the lubricating liquid removing filter. Moreover, reflection of compressed gas at the wall surfaces of the housing 2 and the partition plate 5 is suppressed by the lubricating hquid removing filter, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby, so that the rotating flow of the compressed gas become smooth, and the lubricating hquid separatmg performance is improved. Consequently, it is possible to damp the compressor pulsation noise effectively and improve the lubricating Hquid separating performance without greatly enlarging the size of the separator itself. [Second Embodiment] A lubricating hquid separator 21 according to a second embodiment of the present invention will be described below with reference to Fig. 3. (Structure of the lubricating hquid separator 2l) As shown in Fig. 3, the lubricating hquid separator 21 of this second embodiment is different from the first embodiment in that a demister 26 is 16 disposed on a portion of a side wall of the housing 2 opposed to ihe partition plate 5. As shown in Fig. 3A, the demister 26 is disposed so that a lower end thereof is positioned lower than the lower end of the partition plate 5. The lower end of the demister 26 may be positioned at a height equal to the lower end of the partition plate 5. As shown in Fig. 3B, which is a sectional view taken on hne A-Ain Fig. 3A, the demister 26 is disposed so as not to block the compressed gas inlet port 3. With this arrangement, pressure pulsation of the compressed gas which flows as rotating flow in a flow path 10 formed between the partition plate 5 and the portion of side wall of the housing 2 opposed to the partition plate is diminished suitably in the area from the compressed gas inlet port 3 to a lower end of the flow path 10. Besides, a compressor pulsation noise caused by the rotational flow of the compressed gas in the flow path 10 is diminished to a satisfactory extent in the area from the compressed gas inlet port 3 to the lower end of the flow path 10. Moreover, with the demister 26, reflection of the compressed gas at the wall surface of the housiag 2 is suppressed suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, and scattering of the lubricating hquid separated from the compressed gas is suppressed to a satisfactory extent thereby Consequently the rotating flow of the compressed gas becomes smoother and the lubricating Hquid separating performance is further improved. Further, since the demister 26 does not obstruct the rotating flow of the compressed gas, there is no fear of lowering in ef&ciency of the gas compressor caused by increase of a pressure loss. 17 Other structural points are the same as in ihe nrsx embodiment and therefore an explanation thereof will here be omitted. (Operation of the lubricating hquid separator 2l) The operation of the lubricating hquid separator 21 of this embodiment is different from that of the first embodiment in that, with the demister 26, reflection of the compressed gas at the portion of side wall of the housing 2 opposed to the partition plate 5 is suppressed, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby. As a result, the rotating flow of the compressed gas becomes smooth, and the lubricating liquid separating performance is improved. Other points related to operation are the same as in the first embodiment and therefore an explanation thereof will here be omitted. Thus, the demister 26 for removing lubricating liquid from the compressed gas which enters the ulterior of the housing 2 through the compressed gas inlet port 3 is disposed on the portion of side wall of the housing 2 opposed to the partition plate 5. Consequently pressure pulsation of the compressed gas entering the interior of the housmg 2 and flowing as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side wall opposed to the partition plate 5 is diminished by the demister 26, and a compressor pulsation noise caused by the rotating flow of the compressed gas in the flow path 10 is diminished by the sound absorbing performance of the demister 26. Further, with the demister 26, reflection of the compressed gas at the wall surface of the housing 2 is suppressed, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby, so that the rotating flow of 18 the compressed gas becomes smooth and the lubncaTing Hquid separating performance is improved. Thus, it is possible to damp the compressor pulsation noise effectively and improve the lubricating liquid separating performance without greatly enlarging the size of the separator itself. Besides, since the lower end of the demister 26 disposed on the portion of side wall of the housing 2 opposed to the partition plate 5 is positioned at a height equal to or lower than the lower end of the partition plate 5, not only pressure pulsation of the compressed gas which flows as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side wall opposed to the partition plate 5 can be diminished suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, but also a compressor pulsation noise induced by the rotating flow of the compressed gas in the flow path 10 can be diminished to a satisfactory extent in the area from the compressed gas inlet port 3 to the lower end of the flow path 10. Moreover, with the demister 26, reflection of the compressed gas at the wafl surface of the housing 2 is suppressed suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby to a satisfactory extent, so that the rotating flow of the compressed gas can be made smoother and it is possible to further improve the lubricating liquid separating performance. (Outline of this embodiment) In the lubricating hquid separator 21 of this embodiment, as described above, a lubricating Hquid removing filter (demister 26) is disposed on a portion of a side wall of the housing opposed to the partition plate 5 and 19 its lower end is positioned at a height equal to or louver ihan rhe lower end of the partition plate 5. According to this structure, since the lower end of the lubricating liquid removing filter disposed on the portion of side wall of housing 2 opposed to the partition plate 5 is positioned at a height equal to or lower than the lower end of the partition plate 5, not only pressure pulsation of the compressed gas which flows as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side wall opposed to the partition plate 5 can be diminished suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, but also a compressor pulsation noise induced by the rotating flow of the compressed gas in the flow path 10 can be diminished to a satisfactory extent in the area from the compressed gas inlet port 3 to the lower end of the flow path 10. Moreover, with the lubricating hquid removing filter, reflection of the compressed gas at the wall surface of the housing 2 is suppressed suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, and scattering of the lubricating hquid separated from the compressed gas is suppressed thereby to a satisfactory extent. Consequently, it is possible to further smooth the rotating flow of the compressed gas and further improve the lubricating Hquid separating performance. [Third Embodiment] A lubricating liquid separator 31 according to a third embodiment of the present invention will be described below with reference to Fig. 4. (Structure and Operation of the lubricating liquid separator 3l) As shown in Fig. 4, the lubricating liquid separator 31 of this third 20 embodiment is different from the first and second embo.iiment^ m that the demister 6 is disposed on the outer surface side of the partition plate 5 and that the demister 26 is disposed on a portion of a side wall of the housing 2 opposed to the partition plate 5. As shown in Fig. 4A, the demister 26 is disposed so that its lower end is positioned lower than the lower end of the partition plate 5. The lower end of the demister 26 may be positioned at a height equal to the lower end of the partition plate 5. As shown in Fig. 4B, which is a sectional view taken on line A-A in Fig. 4A, the demister 26 is disposed so as not to block the compressed gas inlet port 3. Other points related to structure and operation are the same as in the other embodiments and therefore an explanation thereof will here be omitted. Thus, since the deinisters G and 26 are disposed respectively on the outer surface side of the partition plate 5 and on the portion of side wall of the housing 2 opposed to the partition plate 5, it is possible to obtain more outstanding effects than in the other embodiments. More particularly, not only pressure pulsation of the compressed gas which flows as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side wall opposed to the partition plate 5 can be further diminished, but also a compressor pulsation noise induced by the rotating flow of the compressed gas in the flow path 10 can be further diminished by the sound absorbing performance of the demisters 6 and 26. Besides, with the demister 6 and 26, reflection of the compressed gas at the wall surfaces of the housing 2 and the partition plate 5 is further suppressed, and scattering of the lubricating 21 liquid separated from ihe compressed gas is funh&r suppressed Thereby, so that the rotating flow of the compressed gas can be made smoother, and it is possible to further improve the lubiicating liquid separating performance. Moreover, since the lower end of the demister 26 disposed on the portion of side wall of the housing 2 opposed to the partition plate 5 is positioned at a height equal to or lower than the lower end of the partition plate 5, not only pressure pulsation of the compressed gas which flows as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side waU opposed to the partition plate 5 can be diminished suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10. but also a compressor pulsation noise induced by the rotating flow of the compressed gas in the flow path 10 csm^ be diminished to a satisfactory extent in the area from the compressed gas inlet port 3 to the lower end of the flow path 10. Further, with the demister 26, reflection of the compressed gas at the wall surface of the housing 2 is suppressed suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, and scattering of the lubricating hquid separated from the compressed gas is suppressed thereby to a satisfactory extent. Consequently, the rotating flow of the compressed gas can be made smoother, and it is possible to further improve the lubricating hquid separating performance. (OutHne of this embodiment) Thus, according to the structure of the lubricating liquid separator 31 of this embodiment, the lubricating Uquid removing filters (demisters 6, 26) are disposed respectively on the outer surface side of the partition plate 5 22 and on the portion of side wall opposed lo the partiaon plate o. According to the structure described above, since the lubricating Hquid removing filters are disposed respectively on the outer surface side of the partition plate 5 and on the portion of side wall of the housing 2 opposed to the partition plate 5, pressure pulsation of the compressed gas which flows rotationally in the flow path 10 formed between the partition plate 5 and the portion of side wall opposed to the partition plate 5 can be further diminished. Besides, a compressor pulsation noise induced by the rotating flow of the compressed gas in the flow path 10 can be further dimioished by the sound absorbing performance of the lubricating Hquid removing filter. Moreover, with the lubricating hquid removing filter, reflection of the compressed gas at the wall surfaces of the housing 2 and the partition plate 5 is further suppressed, and scattering of the lubricating hquid separated from the compressed gas is further suppressed thereby, so that the rotating flow of the compressed gas can be made smoother, and it is possible to further improve the lubricating liquid separating performance. (Modifications of the embodiments) Although embodiments of the present invention are described above, they are mere rllustiations of concrete examples and do not limit the present invention. As to their concrete structures, design modifications may be made where required. Further, the functions and effects described in the above embodiments are mere enumerations of most siutable functions and effects which are brought about by the present invention. The functions and effects of the present invention are not limited to those described in the above embodiments. 23 For example, in the first embodiment, although me demister 6 13 disposed throughout the whole cifcumference on the outer surface side of the partition plate 5 as shown in Fig. IB, no limitation is made to this structure. The demister 6 may be disposed in a Umited area on the outer surface side of the partition plate 5 as shown in Fig. 5A which is a sectional view taken on line A-A in Fig. lA. Further, in the second embodiment, although the demister 26 is disposed throughout the whole circumference of the portion of side wall of the housing 2 opposed to the partition plate 5 as shown in Fig. 3B, no limitation is made to this structure. As shown in Fig. 5B which is a sectional view taken on hne A-A in Fig. 3A, the demister 26 may be disposed in a limited area of the portion of side wall of the hosuig 2 opposed to the partition plate 5. This is also true of the third embodiment. 24 ^"hatis claimed is- 1. A lubricating liquid separator for sepai-ating and recovering lubricating liquid from compressed gas containing the lubricating liquid by creating rotating flow of the compressed gas, the lubricating liquid sepai-ator comprising: a hollow housing; a compressed gas inlet port formed in a side wall of said housing and through which the compressed gas containing the lubricating Hquid passes when flowing into said housing; a compressed gas discharge port formed in an upper wall of said housing and through which the compressed gas after separation of the lubricating liquid passes when discharged fi-om an interior of said housing; a partition plate disposed in the interior of said housing and having a predetermined length in a vertical direction, said partition plate being connected to the upper wall of said housing and enclosing said compressed gas discharge port; and a lubricating liquid removing filter disposed on an outer surface side of said partition plate or on a portion of the side waU opposed to said partition plate, said lubricating liquid removing filter having a sound absorbing performance and functioning to remove the lubricating hquid from the compressed gas containing the lubricating liquid. 2. A lubricating hquid separator according to claim 1, wherein said lubricating liquid removing filter is disposed on each of the outer surface side of said partition plate and the portion of the side wall opposed to said partition plate. 25 3. A lubricating liquid separator according to claim 1, wherein said lubricating liquid removing filter is disposed on the portion of the side wall opposed to said partition plate, and a lower end o£ said lubricating liquid removing filter is positioned at a lieight equal to or lower than a lower end of said partition plate.

Full Text

TITLE OF THE IN\:EXnON LUBRICATING LIQUID SEPARATOR
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a lubricating liquid separator for
separating and recovering lubricating liquid from compressed gas, the
lubricating Hquid being used, for example, in an oil-cooled air compressor, a
freezer, a gas compressor or a water lubrication type air compressor.
2. Description of the Related Art
In screw type or scroll type air/gas compressors or freezers there is used such liquid as oil or water as both lubricant and rotor coolant for rotors in a compressing section, the rotors being in contact with each other. In these gas compressors, compressed gas is discharged in a mixed state with lubricating hquid, and therefore a lubricating Hquid separator for separating and recovering lubricating liquid from the compressed gas is installed in each of the gas compressors.
The lubricating Hquid separator is called an oil recovering device or an oil separator in case of the lubricating liquid being oil. And the lubricating hquid separator is called a water recovering device or a water separator in case of the lubricating liquid being water. According to the principle of the lubricating hquid separator, compressed gas is introduced so as to flow along the circumferential direction from a side surface of a cylindrical housing, and there is produced rotating flow of the compressed
1

gas along an inner -i\-all surface of the housing. By ihe resulting centrifugation effect, the lubricating liquid component is gathered on the inner wall surface of the housing for separation from the gaseous component.
The compressed gas freed from the lubricating liquid to a certain extent by the centrifugation effect is discharged from the lubricating- hquid separator. At this time, the remaining lubricating liquid is usually removed by a metalhc or fibrous lubricating liquid removing filter called demister. The demister is known to exhibit a predetermined sound absorbing performance.
In order to let the centrifugation effect be exhibited to a satisfactory extent, the longer the rotating flow created along the inner wall surface of the housing of the lubricating liquid separator, the better. Therefore, a compressed gas inlet port for introducing the compressed gas into the lubricating liquid separator is generally formed on an upper side of the housing of the lubricating liquid separator. However, since the precipitated lubricating Hquid stays in a lower portion of the housing, a compressed gas discharge port for discharging the compressed gas from the lubricating Hquid separator after separation of the lubricating Hquid is also formed on the upper side of the housing. In view of this point, a cylindrical partition plate having a predetermined length in the vertical direction and which surrounds the compressed gas discharge port is in many cases instaUed within the housing, lest the compressed gas entering from the compressed gas inlet port and containing the lubricating Hquid, and the compressed gas after separation of the lubricating oil and discharged from the compressed gas discharge port should mix each other.
2

In Patent Literature 1 there is disclosed a separator wherein a demister is disposed inside a partition plate. On the other hand, there also is a case where a demister is disposed so as to divide the interior of the housing into two vertically without using a partition plate.
[Patent Literature l]
Japanese Patent Laid-Open Publication No. Sho 47 (l972)-26749
However, in the separator of Patent Literature 1, a compressor pulsation noise is generated within the housing as a result of entry of compressed gas involving pressure pulsation into the housing. Consequently, the separator itself acts as a noise source, contributing greatly to an increase of noise in a gas compressor or the Hte.
In this connection, in Patent Literature 2 is disclosed an oil separator in an oil-cooled compressor wherein a noise damping section is provided in the interior of a vessel to reduce noise, the noise damping section having a casing which encloses a vessel-iaside opening of a gas inlet section and also having a gas-permeable, heat-resistant, sound-absorbing material layer disposed at a position opposed to the opening.
In Patent Literature 3 is disclosed an oil separator wherein a member for inducing a pressure loss is disposed near a tip of a coolant inlet pipe, allowing oil contained in a mixed fluid to be adsorbed to the member, and the flow velocity of the mixed fluid is adjusted appropriately by the member, thereby suppressing noise generated upon collision of fluid with an inner wall of a vessel body.
Further, in Patent Literature 4 is disclosed an oil separator wherein a sound absorbiug material is disposed at a position lower than a gas inlet
3

port in the interior of a vessel not having a partition plate and at a position at least an upper surface of the sound absorbing material is not soaked into oil stored in an oil sump, thereby reducing generated noise. This oil separator is superior in oil separating performance and does not deteriorate the operation efficiency of the associated compressor. In this oil separator, there is disposed a demister so as to divide the interior of the vessel body into two vertically.
[Patent Literature 2]
Japanese Patent LaidOpen Publication No. Hei 8 (1996)-128388
[Patent Literature 3]
Japanese Patent Laid-Open Publication No. 200598534
[Patent Literature 4]
Japanese Patent Laid-Open Publication No. 2007-327439
The demister exhibits a sound absorbing performance to a certain extent, but even if the demister is disposed as in Patent Literatures 1 and 4, there is obtained httle noise damping effect. Even if the demister is disposed outside a lubricating liquid separator, there will be obtained no noise damping effect, because the demister is not designed as a noise damper.
In the oU separator of an oil-cooled compressor disclosed in Patent Literature 2, an increase in the number of parts resxilts from provision of the noise damping section within the vessel, thus giving rise to the problem of increase in cost. In the oil separator disclosed in Patent Literature 3, some improvement is needed so that the pressure loss inducing member disposed near the tip of the coolant inlet pipe may not be scattered by the discharge
4

gas of a high pressure.
In. the oil sepai'ator disclosed in Patent Literature 4, because the partition plate is not provided, scattering of the lubricating liquid after separation from the compressed gas which enters the interior of the housing is conspicuous, thus giving rise to the problem that the separation efficiency becomes lower.
Moreover, in the lubricating liquid separator which utilizes the centrifugation effect, it is necessary to enlarge the vertical length of the housing in order to enhance the separation efficiency. As a result, not only the cost of the lubricating liquid separator itself increases, but also there arises the problem of space when disposing the associated compressor body and the lubricating hquid separator within a single package.
Further, as disclosed in Patent Literature 1, if a demister is disposed inside a partition plate, there arises the problem of lowering in efGciency of the gas compressor due to an increase of pressure loss. On the other hand, if there is formed such a flow path as extends through a demister, it wdl be impossible to expect the demister to exhibit any noise damping effect; besides, the demister cannot play its original role.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a lubricating hquid separator capable of damping a compressor pulsation noise effectively and improving the lubricating liquid separating performance without greatly enlarging the size of the separator itself.
According to the present invention, there is provided a lubricating
5

liquid separator for separating and recoverLag lubricating liquid from compressed gas containing the lubricating liquid by creating rotating flow of the compressed gas, the lubricating liquid separator comprising a hollow housing; a compressed gas inlet port formed in a side wall of the housing and through which the compressed gas containing the lubricating liquid passes when flowing into the housing; a compressed gas discharge port formed in an upper wall of the housing and through which the compressed gas after separation of the lubricating liquid passes when discharged from the interior of the housing; a partition plate disposed in the interior of the housing and having a predetermined length in the vertical direction, the partition plate being connected to the upper wall of the housing and enclosing the compressed gas discharge port; and a lubricating liquid removing filter disposed on an outer surface side of the partition plate or on a portion of the side wall opposed to the partition plate, the lubricating liquid removing filter having a sound absorbing performance and functioning to remove the lubricating liquid from the compressed gas containing the lubricating liquid. According to the above structure, the lubricating liquid removing filter for removing the lubricating liquid firom the compressed gas which enters the interior of the housing through the compressed gas inlet port is disposed on the outer surface side of the partition plate or on the portion of side wall of the housing opposed to the partition plate. Consequently, pressure pulsation of the compressed gas which enters the interior of the housing and which flows as rotating flow in a flow path formed between the partition plate and the portion of side wall opposed to the partition plate is diminished by the lubricating liquid removing filter, and a compressor
6

pulsation noise caused by the rotating flow of the compressed gas in the flow path is diminished by the sound absorbing perfoimance of the lubricating liquid removing filter. Besides, with the lubricating Hquid removing filter, reflection of the compressed gas at the wall surfaces of the housing and the partition plate is suppressed, and scattering of the lubricating Kquid separated from the compressed gas is suppressed thereby, so that the rotating flow of the compressed gas become smooth and the lubricating liquid separating performance is improved. Consequently, it is possible to damp the compressor pulsation noise effectively and improve the separation performance without greatly enlarging the size of the separator itself.
In the lubricating liquid separator of the present invention, the lubricating hquid removing filter may be disposed on each of the outer surface side of the partition plate and the portion of side wall opposed to the partition plate. According to this structure, since the lubricating liquid removing filter is disposed on both the outer surface side of the partition plate and the portion of side wall of the housing opposed to the partition plate, pressure pulsation of the compressed gas which flows as rotating flow in the flow path formed between the partition plate and the portion of side wall opposed to the partition plate can be further diminished. Besides, the compressor pulsation noise caused by the rotating flow of the compressed gas in the flow path can be further diminished by the sound absorbing performance of the lubricating liquid removing filter. Moreover, with the lubricating liquid removing filter, reflection of the compressed gas at the wall surfaces of the housing and the partition plate is further suppressed, and scattering of the lubricating hquid separated &om the compressed gas is
7

further suppressed, so that the rotatang flow of rhe compressed gas can be made smoother, and the lubricating liquid separating performance can be further improved.
In the lubricating liquid separator of the present invention, the lubricating liquid removing filter may be disposed on the portion of side wall opposed to the partition plate and a lower end of the lubricating hquid removing filter may be positioned at a height equal to or lower than a lower end of the partition plate. According to this structure, since the lower end of the lubricating Uquid removing filter disposed on the portion of side wall of the housing opposed to the partition plate is positioned at a height equal to or lower than the lower end of the partition plate, pressitre pulsation of the compressed gas which flows as rotating flow in the flow path formed between the partition plate and the portion of side wall opposed to the partition plate can be suitably diminished in the area from the compressed gas inlet port to a lower end of the flow path. Besides, a compressor pulsation noise caused by the rotating flow of the compressed gas in the Hov.' path can be diminished thoroughly in the area fiora the compressed gas inlet port to the lower end of the flow path. Moreover, with the lubricating Mquid removing filter, reflection of the compressed gas at the housing wall surface is suitably suppressed in the area from the compressed gas inlet port to the lower end of the flow path and scattering of the lubricating liquid separated from the compressed gas is thereby suppressed to a satisfactory extent. Therefore, the rotating flow of the compressed gas can be made smoother and it is possible to further improve the lubricating liquid separating performance.
8

BREIF DESCRIPTION OF THE DRAV\1NGS
Fig. lAis a sectional view of a lubricating liquid separator according to an embodiment of the present invention, and Fig. IB is a sectional view taken on line A-Ain Fig. \A',
Fig. 2 is a graph showing experimental results;
Fig. 3A is a sectional view of a lubricating oil separator according to another embodiment of the present invention, and Fig. 3B is a sectional view taken on line A-A in Fig. 3A;
Fig. 4Ais a sectional view of a lubricating liquid sepai'ator according to a further emhodiment of the present invention, and Fig. 4B is a sectional view taken on line A-A in Fig. 4 A; and
Fig. 5Ais a sectional view taken online A-Ain Fig. lA, and Fig. 5B is a sectional view taken on line A-A in Fig. 3A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Lubricating liquid separators embodying the present invention will
be described below with reference to the accompanying drawings.
[First Embodiment]
A lubricating liquid separator 1 according to a first embodiment of
the present invention wiU be described below with reference to Fig. 1.
(Structure of the lubricating Hquid separator l)
The lubricating liquid separator 1 constitutes a part of a gas
compressor together with a compressor body (not shown). As shown in Fig.
1, the lubricating hquid separator 1 has a cylindrical housing 2 made of
metal or resin having pressure resistance. The housing 2 is installed in a
9

vertically (longitudinally^ upright state. The shape of the housing 2 is nor limited to the cyhndrical shape, but may be an elliptic shape or a polygonal prism shape. The housing 2 has a compressed gas inlet port 3 formed in a side wall thereof. Further, a lubricating oil sump portion 8 is formed at an inside bottom of the housing 2.
The compressed gas inlet port 3 is connected through a gas inlet pipe 9 to a discharge port (not shown) of a compressor body. Compressed gas compressed by the compressor body and containing lubricating hquid passes through the compressed gas inlet port 3 and enters the interior of the housing 2. As shown in Fig. IB which is a sectional view taken on hne A-A in Fig. lA, the compressed gas inlet port 3 is foimed so as to be parallel to a tangent to the peripheral surface of the cylindrical housing 2. Consequently, the compressed gas which passes through the compressed gas inlet port 3 flows from a side face portion of the housing 2 into the housing 2 along the circumferential direction, resulting in creation of rotating flow of the compressed gas along the inner wall suiface of the housing 2. With this rotating flow, a centrifugation effect (cyclone effect) is induced tn the compressed gas. As shown in Fig. lA. the compressed gas inlet port 3 is located at an upper position in the longitudinal direction of the housing 2. As a result, the rotating flow of the compressed gas becomes longer and the centrifugation effect for separating the lubricating hquid is exhibited to a satisfactory extent.
Moreover, a compressed gas discharge port 4 is formed in a top wall of the housing 2, through which the compressed gas separated from the lubricating liquid is discharged. The compressed gas discharged from the
10

compressed gas discharge port 4 is conveyed to the nexr process.
In the interior of the housing 2 is disposed a cylindrical partition plate 5 having a predetermined length in the vertical direction, connected to the top wall of the housing 2 and enclosing the compressed gas dischai-ge port 4. A lower end of the partition plate 5 is positioned lower than the compressed gas inlet port 3. And the compressed gas inlet port 3 and the compressed gas discharge port 4 are consequently partitioned from each other by the partition plate 5, whereby the compressed gas entering from the compressed gas inlet port 3 and containing lubricating Hquid and the compressed gas dischai-ged from the compressed gas discharge port 4 and freed from the lubricating liquid are prevented from being mixed with each other. The shape of the partition plate 5 is not hmited to the cylindrical shape, but may be an elliptic shape or a polygonal prism shape.
A lubricating liquid removing fdter (demister) 6 is mounted on an outer surface side of the partition plate 5 to remove lubricating liquid from the compressed gas which contains the lubricating liquid. The demister 6 is formed of a metaUic or resinous, fibrous, porous material, and has a sound absorbing performance. With the demister 6 thus mounted on the outer surface side of the partition plate 5, reflection of the compressed gas at the wall surface of the partition plate 5 is suppressed, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby. Besides, since the demister 6 does not obstruct the rotating flow of the compressed gas, there is no fear of lowering in ef&ciency of the gas compressor caused by increase of a pressure loss.
A lower end of the demister 6 is positioned at a height equal to or
11

higher than the lower end of the partition plat^ 5. whereby the lubricatine liqxiid adhered to the demister 6 is prevented from being discharged fcom the compressed gas discharge port 4 together with the compressed gas after separation of lubricating liquid.
The demister 6 may be disposed not on the outer surface side of the partition plate 5 but on the portion of side wall of the housing 2 opposed to the partition plate 5. As to this structure, a description will be given below in a second embodiment of the present invention.
In a bottom wall of the housing 2, which is the bottom of the lubricating liquid sump portion 8, there is formed a lubricating liquid discharge port 7. The lubricating Kquid discharge port 7 is for recovering the lubricating liquid stored in the lubricating liquid sump portion 8. The lubricating liquid recovered from the lubricating liquid sump portion 8 is returned to the compressor body. (Operation of the lubricating hquid separator l)
The following description is now provided about the operation of the lubricating Hquid separator 1.
Since the compressed gas inlet port 3 and the compressed gas discharge port 4 are partitioned from each other by the partition plate 5, the lubricating hquid^containing compressed gas which enters the interior of the housing 2 from the compressor body through the compressed gas inlet port 3 passes through a flow path 10 formed between the demister 6 and a portion of the housing 2 opposed to the demister 6. Therefore, the lubricating liquid-containing" compressed gas which enters the interior of the housing 2 is never mixed with the compressed gas which is discharged from the
12

compressed gas discharge port 4 after separation of lubricaring Hquid.
In the flow path 10, rotating flow along the inner wall surface of the cylindrical housing 3 is created in the compressed gas, whereby a centrifugation effect (cyclone effect) is developed in the compressed gas. As a result, lubricating liquid is separated from the compressed gas. In this connection, the compressed gas flowing as rotating flow in the flow path 10 strikes against the demister 6, whereby pressure pxdsation of the compressed gas is diminished. At the same time, a compressor pulsation noise caused by the rotating flow of the compressed gas is diminished by the sound absorbing performance of the demister G.
The compressed gas freed from the lubricating liquid by the rotating flow passes through the demister 6, whereby the lubricating Uquid is further removed. In this case, with the demister 6, reflection of the compressed gas at the wall surface of the partition plate 5 is suppressed, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby. Consequently, the rotating flow of the compressed gas becomes smooth and the lubricating Uquid separating performance is improved. Moreover, since the demister 6 does not obstruct the rotating flow of the compressed gas, there is no fear of lowering in efficiency of the gas compressor caused by increase of a pressure loss.
The lubricating hquid separated from the compressed gas adheres to an inner wall surface of the side wall of the housing 2. As a resiilt, droplets of the lubricating liquid grow on the waU surface, and the thus-grown droplets flow down along the wall surface of the housing 2 by their own weights, so that the lubricating liquid accumulates in the lubricating Hquid
13

sump portion 8.
On the other hand, the compressed ^as after separation of the lubricating liquid is discharged from the compressed gas discharge port 4, and is conveyed to the next process.
Thus, the demister 6 for removing the lubricating liquid firom the compressed gas which enters the interior of the housmg 2 through the compressed gas inlet port 3 is disposed on the outer surface side of the partition plate 5. Therefore, pressure pulsation of the compressed gas entering the interior of the housing 2 and flowing rotationaUy in the flow path 10 defined between the partition plate 5 and the portion of side wall of the housing 2 opposed to the partition plate 5 is diminished by the demister 6, and a compressor pulsation noise caused by the rotating flow of the compressed gas in the flow path 10 is diminished by the sound absorbing performance of the demister 6. Further, reflection of the compressed gas at the wall surface of the partition plate 5 is suppressed by the demister 6, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby, so that the rotating flow of the compressed gas becomes smooth and the lubricating hquid separating performance is improved. Consequently, it is possible to damp the compressor pulsation noise effectively and improve the lubricating liquid separating performance without greatly enlarging the size of the separator itself. (Experimental Results)
Fig. 2 shows experimental results obtained by comparing a noise level at a 1 m-spaced position from a lubricating hquid separator of a conventional structure and, the noise level 1 m-spaced from the lubricating
14

hquid separator 1 of this embodiment. The convenuonal iubricamig hquid separator is of a structure not having the demister 6 in the lubricating hquid separator 1 shown in Fig. 1.
From Fig. 2 it is seen that the provision of the demister 6 on the outer surface side of the partition plate 5 leads to lowering of the noise level. (Outline of this embodiment)
In the lubricating liquid separator 1 of this embodiment, as described above, lubricating hquid is separated and recovered from compressed gas containing the lubricating hquid by creating rotating flow of the compressed gas. The lubricating separator 1 comprises a hollow housing 2, a compressed gas inlet port 3 formed in a side wall of the housing 2 and through which the compressed gas containing the lubricating hquid passes when flowing into the housing 2, a compressed gas discharge port 4 formed in a top wall of the housing 2 and through which the compressed gas after separation of the lubricating Hquid passes when discharged from the interior of the housing 2, a pai'titiou plate 5 disposed in the interior of the housing 2 and having a predetermined length in the vertical direction, the partition plate 5 being connected to the top wall of the bousing 2 and enclosing the compressed gas discharge port 4, and a lubricating Hqmd removing filter (demister 6) disposed on an outer surface side of the partition plate 5 or on a portion of the side wall of the housing 2 opposed to the partition plate 5, the lubricating hquid removing filter having a sound absorbing performance and functioning to remove the lubricating hquid from the compressed gas containing the luhricating liquid.
According to this structure, the lubricating hquid removing filter for
15

removing lubricating liquid from the compressed gas which enters the mterior of the housing 2 through the compressed gas inlet port 3 is disposed on an outer surface side of the partition plate 5 or on the portion of side wall of the housing 2 opposed to the partition plate 5. Therefore, pressure pulsation of the compressed gas which enters the interior of the housing 2 and which flows as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side wall of the housing 2 opposed to the partition plate 5 is diminished by the lubricating hquid removing filter, and a compressor pulsation noise caused by the rotating flow of the compressed gas in the flow path 10 is diminished by the sound absorbing performance of the lubricating liquid removing filter. Moreover, reflection of compressed gas at the wall surfaces of the housing 2 and the partition plate 5 is suppressed by the lubricating hquid removing filter, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby, so that the rotating flow of the compressed gas become smooth, and the lubricating hquid separatmg performance is improved. Consequently, it is possible to damp the compressor pulsation noise effectively and improve the lubricating Hquid separating performance without greatly enlarging the size of the separator itself. [Second Embodiment]
A lubricating hquid separator 21 according to a second embodiment of the present invention will be described below with reference to Fig. 3. (Structure of the lubricating hquid separator 2l)
As shown in Fig. 3, the lubricating hquid separator 21 of this second embodiment is different from the first embodiment in that a demister 26 is
16

disposed on a portion of a side wall of the housing 2 opposed to ihe partition plate 5.
As shown in Fig. 3A, the demister 26 is disposed so that a lower end thereof is positioned lower than the lower end of the partition plate 5. The lower end of the demister 26 may be positioned at a height equal to the lower end of the partition plate 5. As shown in Fig. 3B, which is a sectional view taken on hne A-Ain Fig. 3A, the demister 26 is disposed so as not to block the compressed gas inlet port 3. With this arrangement, pressure pulsation of the compressed gas which flows as rotating flow in a flow path 10 formed between the partition plate 5 and the portion of side wall of the housing 2 opposed to the partition plate is diminished suitably in the area from the compressed gas inlet port 3 to a lower end of the flow path 10. Besides, a compressor pulsation noise caused by the rotational flow of the compressed gas in the flow path 10 is diminished to a satisfactory extent in the area from the compressed gas inlet port 3 to the lower end of the flow path 10. Moreover, with the demister 26, reflection of the compressed gas at the wall surface of the housiag 2 is suppressed suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, and scattering of the lubricating hquid separated from the compressed gas is suppressed to a satisfactory extent thereby Consequently the rotating flow of the compressed gas becomes smoother and the lubricating Hquid separating performance is further improved. Further, since the demister 26 does not obstruct the rotating flow of the compressed gas, there is no fear of lowering in ef&ciency of the gas compressor caused by increase of a pressure loss.
17

Other structural points are the same as in ihe nrsx embodiment and therefore an explanation thereof will here be omitted. (Operation of the lubricating hquid separator 2l)
The operation of the lubricating hquid separator 21 of this embodiment is different from that of the first embodiment in that, with the demister 26, reflection of the compressed gas at the portion of side wall of the housing 2 opposed to the partition plate 5 is suppressed, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby. As a result, the rotating flow of the compressed gas becomes smooth, and the lubricating liquid separating performance is improved.
Other points related to operation are the same as in the first embodiment and therefore an explanation thereof will here be omitted.
Thus, the demister 26 for removing lubricating liquid from the compressed gas which enters the ulterior of the housing 2 through the compressed gas inlet port 3 is disposed on the portion of side wall of the housing 2 opposed to the partition plate 5. Consequently pressure pulsation of the compressed gas entering the interior of the housmg 2 and flowing as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side wall opposed to the partition plate 5 is diminished by the demister 26, and a compressor pulsation noise caused by the rotating flow of the compressed gas in the flow path 10 is diminished by the sound absorbing performance of the demister 26. Further, with the demister 26, reflection of the compressed gas at the wall surface of the housing 2 is suppressed, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby, so that the rotating flow of
18

the compressed gas becomes smooth and the lubncaTing Hquid separating performance is improved. Thus, it is possible to damp the compressor pulsation noise effectively and improve the lubricating liquid separating performance without greatly enlarging the size of the separator itself.
Besides, since the lower end of the demister 26 disposed on the portion of side wall of the housing 2 opposed to the partition plate 5 is positioned at a height equal to or lower than the lower end of the partition plate 5, not only pressure pulsation of the compressed gas which flows as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side wall opposed to the partition plate 5 can be diminished suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, but also a compressor pulsation noise induced by the rotating flow of the compressed gas in the flow path 10 can be diminished to a satisfactory extent in the area from the compressed gas inlet port 3 to the lower end of the flow path 10. Moreover, with the demister 26, reflection of the compressed gas at the wafl surface of the housing 2 is suppressed suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, and scattering of the lubricating liquid separated from the compressed gas is suppressed thereby to a satisfactory extent, so that the rotating flow of the compressed gas can be made smoother and it is possible to further improve the lubricating liquid separating performance. (Outline of this embodiment)
In the lubricating hquid separator 21 of this embodiment, as described above, a lubricating Hquid removing filter (demister 26) is disposed on a portion of a side wall of the housing opposed to the partition plate 5 and
19

its lower end is positioned at a height equal to or louver ihan rhe lower end of the partition plate 5.
According to this structure, since the lower end of the lubricating liquid removing filter disposed on the portion of side wall of housing 2 opposed to the partition plate 5 is positioned at a height equal to or lower than the lower end of the partition plate 5, not only pressure pulsation of the compressed gas which flows as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side wall opposed to the partition plate 5 can be diminished suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, but also a compressor pulsation noise induced by the rotating flow of the compressed gas in the flow path 10 can be diminished to a satisfactory extent in the area from the compressed gas inlet port 3 to the lower end of the flow path 10. Moreover, with the lubricating hquid removing filter, reflection of the compressed gas at the wall surface of the housing 2 is suppressed suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, and scattering of the lubricating hquid separated from the compressed gas is suppressed thereby to a satisfactory extent. Consequently, it is possible to further smooth the rotating flow of the compressed gas and further improve the lubricating Hquid separating performance. [Third Embodiment]
A lubricating liquid separator 31 according to a third embodiment of the present invention will be described below with reference to Fig. 4. (Structure and Operation of the lubricating liquid separator 3l)
As shown in Fig. 4, the lubricating liquid separator 31 of this third
20

embodiment is different from the first and second embo.iiment^ m that the demister 6 is disposed on the outer surface side of the partition plate 5 and that the demister 26 is disposed on a portion of a side wall of the housing 2 opposed to the partition plate 5.
As shown in Fig. 4A, the demister 26 is disposed so that its lower end is positioned lower than the lower end of the partition plate 5. The lower end of the demister 26 may be positioned at a height equal to the lower end of the partition plate 5. As shown in Fig. 4B, which is a sectional view taken on line A-A in Fig. 4A, the demister 26 is disposed so as not to block the compressed gas inlet port 3.
Other points related to structure and operation are the same as in the other embodiments and therefore an explanation thereof will here be omitted.
Thus, since the deinisters G and 26 are disposed respectively on the outer surface side of the partition plate 5 and on the portion of side wall of the housing 2 opposed to the partition plate 5, it is possible to obtain more outstanding effects than in the other embodiments. More particularly, not only pressure pulsation of the compressed gas which flows as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side wall opposed to the partition plate 5 can be further diminished, but also a compressor pulsation noise induced by the rotating flow of the compressed gas in the flow path 10 can be further diminished by the sound absorbing performance of the demisters 6 and 26. Besides, with the demister 6 and 26, reflection of the compressed gas at the wall surfaces of the housing 2 and the partition plate 5 is further suppressed, and scattering of the lubricating
21

liquid separated from ihe compressed gas is funh&r suppressed Thereby, so that the rotating flow of the compressed gas can be made smoother, and it is possible to further improve the lubiicating liquid separating performance.
Moreover, since the lower end of the demister 26 disposed on the portion of side wall of the housing 2 opposed to the partition plate 5 is positioned at a height equal to or lower than the lower end of the partition plate 5, not only pressure pulsation of the compressed gas which flows as rotating flow in the flow path 10 formed between the partition plate 5 and the portion of side waU opposed to the partition plate 5 can be diminished suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10. but also a compressor pulsation noise induced by the rotating flow of the compressed gas in the flow path 10 csm^ be diminished to a satisfactory extent in the area from the compressed gas inlet port 3 to the lower end of the flow path 10. Further, with the demister 26, reflection of the compressed gas at the wall surface of the housing 2 is suppressed suitably in the area from the compressed gas inlet port 3 to the lower end of the flow path 10, and scattering of the lubricating hquid separated from the compressed gas is suppressed thereby to a satisfactory extent. Consequently, the rotating flow of the compressed gas can be made smoother, and it is possible to further improve the lubricating hquid separating performance. (OutHne of this embodiment)
Thus, according to the structure of the lubricating liquid separator 31 of this embodiment, the lubricating Uquid removing filters (demisters 6, 26) are disposed respectively on the outer surface side of the partition plate 5
22

and on the portion of side wall opposed lo the partiaon plate o.
According to the structure described above, since the lubricating Hquid removing filters are disposed respectively on the outer surface side of the partition plate 5 and on the portion of side wall of the housing 2 opposed to the partition plate 5, pressure pulsation of the compressed gas which flows rotationally in the flow path 10 formed between the partition plate 5 and the portion of side wall opposed to the partition plate 5 can be further diminished. Besides, a compressor pulsation noise induced by the rotating flow of the compressed gas in the flow path 10 can be further dimioished by the sound absorbing performance of the lubricating Hquid removing filter. Moreover, with the lubricating hquid removing filter, reflection of the compressed gas at the wall surfaces of the housing 2 and the partition plate 5 is further suppressed, and scattering of the lubricating hquid separated from the compressed gas is further suppressed thereby, so that the rotating flow of the compressed gas can be made smoother, and it is possible to further improve the lubricating liquid separating performance.
(Modifications of the embodiments)
Although embodiments of the present invention are described above, they are mere rllustiations of concrete examples and do not limit the present invention. As to their concrete structures, design modifications may be made where required. Further, the functions and effects described in the above embodiments are mere enumerations of most siutable functions and effects which are brought about by the present invention. The functions and effects of the present invention are not limited to those described in the above embodiments.
23

For example, in the first embodiment, although me demister 6 13 disposed throughout the whole cifcumference on the outer surface side of the partition plate 5 as shown in Fig. IB, no limitation is made to this structure. The demister 6 may be disposed in a Umited area on the outer surface side of the partition plate 5 as shown in Fig. 5A which is a sectional view taken on line A-A in Fig. lA. Further, in the second embodiment, although the demister 26 is disposed throughout the whole circumference of the portion of side wall of the housing 2 opposed to the partition plate 5 as shown in Fig. 3B, no limitation is made to this structure. As shown in Fig. 5B which is a sectional view taken on hne A-A in Fig. 3A, the demister 26 may be disposed in a limited area of the portion of side wall of the hosuig 2 opposed to the partition plate 5. This is also true of the third embodiment.
24

^"hatis claimed is-
1. A lubricating liquid separator for sepai-ating and recovering
lubricating liquid from compressed gas containing the lubricating liquid by
creating rotating flow of the compressed gas, the lubricating liquid sepai-ator
comprising:
a hollow housing;
a compressed gas inlet port formed in a side wall of said housing and through which the compressed gas containing the lubricating Hquid passes when flowing into said housing;
a compressed gas discharge port formed in an upper wall of said housing and through which the compressed gas after separation of the lubricating liquid passes when discharged fi-om an interior of said housing;
a partition plate disposed in the interior of said housing and having a predetermined length in a vertical direction, said partition plate being connected to the upper wall of said housing and enclosing said compressed gas discharge port; and
a lubricating liquid removing filter disposed on an outer surface side of said partition plate or on a portion of the side waU opposed to said partition plate, said lubricating liquid removing filter having a sound absorbing performance and functioning to remove the lubricating hquid from the compressed gas containing the lubricating liquid.
2. A lubricating hquid separator according to claim 1, wherein said
lubricating liquid removing filter is disposed on each of the outer surface side
of said partition plate and the portion of the side wall opposed to said
partition plate.
25

3. A lubricating liquid separator according to claim 1, wherein said lubricating liquid removing filter is disposed on the portion of the side wall opposed to said partition plate, and a lower end o£ said lubricating liquid removing filter is positioned at a lieight equal to or lower than a lower end of said partition plate.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=7jj43cVRHQ+bHnUDBaiZrg==&loc=egcICQiyoj82NGgGrC5ChA==

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Patent Number

270080

Indian Patent Application Number

848/CHE/2009

PG Journal Number

49/2015

Publication Date

04-Dec-2015

Grant Date

27-Nov-2015

Date of Filing

13-Apr-2009

Name of Patentee

KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)

Applicant Address

10-26, WAKINOHAMA-CHO 2-CHOME, CHUO-KU, KOBE-SHI, HYOGO 651-8585

Inventors:

#	Inventor's Name	Inventor's Address
1	SAKATANI, TORU	C/O KOBE CORPORATE RESEARCH LABORATORIES, IN KOBE STEEL, LTD., 5-5, TAKATSUKADAI 1-CHOME, NISHI-KU, KOBE-SHI, HYOGO 651-2271
2	KANKI, EIJI	C/O HARIMA PLANT IN KOBE STEEL, LTD., 41, NIIJIMA, HARIMA-CHO, KAKO-GUN, HYOGO 675-0155
3	KIMURA, YASUMASA	C/O KOBE CORPORATE RESEARCH LABORATORIES, IN KOBE STEEL, LTD., 5-5, TAKATSUKADAI 1-CHOME, NISHI-KU, KOBE-SHI, HYOGO 651-2271

PCT International Classification Number

F01M11/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2008-104493	2008-04-14	Japan