Title of Invention

"REACTOR DEVICE FOR FREE-FLOWING AND HIGHER-VISCOSITY MEDIA"

Abstract

Reactor Device for free-flowing and higher-viscosity Media. A reactor davica is proposed for free-flowing and higher-viscosity madia especially far polymers and polycondensaticn of polyaatara, and which ensures outstanding, uniform quality of the reaction products with a relatively simple construction and improved stability against warping and bending of the raactar. The reactor device comprises a horizontally-disposed housing (1), at ' one snd of which there is disposed an inlet (4) fo:r supply of the medium, and at the other end of which thera is an nutlet (5) for the ' reaction products. Within the housing (1) of the reactor device a rotor (1) is rotatably mounted, According to the invention, the rotor (8) has a hollow cylinder (9). which is provr.ded with openings (10) and annular members (12, 13) for moving and transporting the medium. The hollow cylinder (9) is partly immersed in the frse-flcwing medium, the openings (10) in the hollow cylinder (9) ensuring additional admixture of tha medium.

Full Text

The invention relates to a reactor device for free-flowing and higher-viscosity media according to the preamble to the main claim. There is known from DE 21 00 615 a reaction vessel for materials in a free-flowing condition, particularly for the polycondensation cf prepolymers into polyester wich a high molecular weight, and which comprises a horizontally-aligned reactor housing with an inlet at one end and an outlet at the other end and an arrangement for moving and cransporting the free-flowing material, said arrangement, in the lower region of the interior of the reactor, being rctatable with small degree of play about an axis extending in the direction of the longitudinal axis of the reactor housing. The rotacable moving and transporting arrangement is in the form cf a support framework attached to coaxial stub shafts; discs are attached in the region of their circumferences to this support frame. In the direction of the axis of rotation, the discs are successively inclined with respsct to said axis in such a way that of the two points which lie on the same diameter on the circumferanee of each disc and respectively have the smallest distance from each of the two end faces of the reactor housing, the points of all discs respectively lying closer to onia of the end faces lie on a helix coaxial with the axi.ai of rotation. The points interconnected by this notional helix are termed trace points, in this way there La achieved a transport of the medium from the inlet to the outlet. In such a known reactor vessel, for exampi.e, free-flowing and viscous monomers and prepolymers are supplied at the inlet to the reactor housing, are moved in the reactor, are locally mixed and transported through the housing, in order in this way to carry out the procedure of a polymerisation process, The polymerisation products ara removed a- the outlet. The medium present in the reactor is mixed and raised locally by each rotating disc, films and sitzriations of the product forming or. the discs, while the viscous medium runs off the discs during the period of the rotary movement, During the mechanical action on the reacting medium the desired polymer is formed cut of the raw materials, while reaction components which are released evaporate, and are extracted as exhaust vapours. Accordingly, there is provided reactor device for free-flowing media, particularly for polymers for polycondensation of polyesters, with a horizontally-disposed housing, which has at one end an inlet for supply of medium and at the other end an outlet for its removal, and with a rotor mounted rotatably in the housing via stub shafts, said rotor having annular members for moving and/or transporting the medium, characterised in that the rotor has a hollow cylinder connected to stub shafts and provided with openings, the annular members being attached to the said hollow cylinder. The purpose underlying the invention is further to develop a reactor device according to prior art in such a way that a reaction product of excellent quality is achieved with a relatively simple construction with improved stability against warping and bending. This purpose is fulfilled according to the invention by the characterising features of the main claim in conjunction with the features in the preamble. By virtue of the fact that the rotor is in the form of a hollow cylinder connected to the stub shafts and provided with openings, and upon which ths annular members are attached transversely to the Longitudinal axis of the reactor casing, on the one ha:id stability is increased and on the other the duration time of the medium may be meaningfully controlled by corresponding design and number of the annular members. The hollow cylinder provided with openings has, because of its high mechanical section modulus, a high degree of resistance to bending, so that the degree of bending is extremely small. At the same time, the openings in the hollow cylinder reinforce the mixing of the medium, forming three surfaces, which favour evaporation. Advantageous further developments and improvements are possible by means of the measures indicated in the secondary claims. If the annular members are inclined towards the axis of rotation, they execute a tumbling movement, which effects locally a more intense mixing of the polymer melt. By means of the inclined annular mambera, the medium is additionally transported from tie inlet towards the output cone. The angle of inclination is so selected that a precisely-defined spectrum of duration times is produced over the entire reactor length. A favourable arrangement of the annular members is achieved by inclining the annular members in such a way that their trace points form a helix over the length of the rotor. This the trace point of an annular member is that point which, with respect to one of the two end faces of the housing, is the smallest distance way. Thus it is sufficient if the annular membesrs have in groups a trace point which lies on such a helix. A particularly good transportation is effected with this arrangement if the annular members do not hinder too much the axial movement; cf the medium. For this purpose, on the one hand the slot between housing and external diameter of the annular members must be so selected that the rotating annular members oppose to the flow of medium a resistance which is smaller than the transporting movement achieved by the off-senting of the trace points. On the other hand, the annular members and discs must be provided with openings such that the increasing viscosity of the medium along the travel path is taken into account. It is of particular advantage if, in the direction of travel, the free cross-sections of the annular members and/or the spacings between the annular mambers and/or the size of the openings in the hollow cylinder increase, this being achievable in zones, as because of chese measures adaptation of the reaction conditions to the state of the medium, i.e. substantially its viscosity, is undertaken, so that the spoctrum of duration times may be controlled even mons precisely. This is reinforced by the fact that the annular members have in groups the same angle of incidence and the same* trace point. The grouped arrangement of parallel annular members leads to zones with a reduced axial transporting effect, i.e. cascade-like zones are formed by means of which the duration time pattern for various produces may be adapted in correspondence with the kinetics of the reaction. In order to increase the cascading effect of discs in a grouped setting with identical trace point setting, these may also for example be so constructed that when a group of three discs is provided, the central disc has a lesser or opposed incidence, or has a trace point which is off-set back, which has a favourable influence on the mixing effect within a cascade group. The construction of the reactor may be simplified in that the same constructive conditions are provided for groups or zones. By means of the provision of additional rings, which are attached to the internal circumference of the hollow cylinder, the medium or the resultant foam is decelerated on the internal walla of the follow cylinder in order to counter axial throug.flow and in order to prevent direct axial further flow on the inner walls of the hollow cylinder, the foam arising particularly in the initial area of the reactor in which the expansion and main gas extraction zone lies, and where violent reactions occur. By means or providing one or a plurality of baffle arrangements, the medium is deflected in a controlled manner, and a cascading effect is also thereby achieved. More advantageously, ir. the higher-viscos:.ty region, stripper rods are disposed between the annular members in the sump of medium, by means of which bridge formation between the discs and excessive oblique positions of the level are avoided, with corresponding formation, e.g. in a shape like a ploughshare, these stripper rods contribute to mixing and transporting the medium. Tile design of the outlet as an output cons and a baffle disposed in front of the output cone with a stripper rotating at that point and a mixer, provide a more uniform output flow of the medium, the baffle representing a decoupling from the rotary motion, and a horizontal/ measurable level of medium is achieved which is independent of the velocity of tie basket mixer, In order to keep the container surfaces above the fluid level free of deposits, the eccentric arrangement of hollow cylinder and reactor housing in conjunction with the arrangement of the gas extraction nozisle at the rear end of the reactor casing make some contribution. The through-flowing reaction vapours bring about a washing effect, while simultaneously, due to the output area, which is enlarged by the output cone described, a suction effect at the particularly critical lower wall areas of the gas extraction nozzle, and thus entrainment of particles, are avoided. The construction also described of the hollow cylinder also has an effect hers, as the inner araa of the hollow cylinder is not blocked by closed, falling films of medium. The medium rather falls in skeins; between the openings in the hollow cylinder, so that sufficient free area remains for the removal of the reaction vapours, i.e. the speeds are low enough ir. order to prevent entrainment of product. As a further measure, the adhesion of oligomers and the formation of undesired deposits are avoided by controlled additional heating in the upper peak area of the housing. Two embodiments of the invention given by way of example are explained in more detail in the following description and illustrated in the drawings. Shown are: Figure 1: A cross-section through a reactor device according to the invention; Figure 2: A plan view of the baffle arrangement used in Figure l; Figure 3: A plan view of the rod-shaped :a tripper members disposed between the annular members; Figure 4: A plan view of the terminal baffle provided in Figure l in the output area; Figure 5: A cress-section through a second reactor device according to the invention; Figure S: A plan view of the red-shaped and ploughshare-shaped strippers provided in Figures i and/or 5, and Figure 7: A plan view of the terminal baffle provided in Figure 5 in the output area. EXAMPLE 1: The reactor illustrated in Figure l is particularly suitable for free-flowing media. it has a housing l, provided with a heating jacket 2, a heat-conducting medium being passed via a pipeline 3 at a plurality of points, seen over the length of the housing l, at both sides into the heating jacket 2. 9y means of this measure, distortion is avoided during heating-up of the overall reactor device. Provided at one end in the housing is an inlet 4 for the input of polymer, and at the other end an outlet 5 for the extraction of polymer. Rotarily mounted in the housing l via stub shafts 6, 7 which are passed through the end walls of the housing, is a rotor, the longitudinal axis of this rotor 3 in the embodiment being slightly off-set downwards (see Figure l) to the longitudinal axis of the housing l, in order to leave free in the upper area slightly more space for the reaction vapours, e.g. glycol ar.d aldehyde vapours or other such gases. At the other end of the housing l, seen in the transport direction of the polymer, there is disposed a gas extractor nozzle 21. The rotor 8 has a hollow cylinder, a cylindrical basket 9 provided with rectangular openings 10, between which there remain longitudinally and transversely-oriented webs 11, so that a grid-shaped arrangement or a grid-Shaped -frame results. Basically the term hollow cylinder 9 refers to such a grid-shaped arrangement, the type and method of its production not being essential to the invention. It is advantageous if the webs are continuous in design, Securely disposed in sequence on the outer surface of the hollow cylinder 9 or on the webs 11 are perforated discs 12 and spoked wheels 13 as transporting and stirring members, seen over the length of the rotor 8. Provided between the perforated discs in the lower area of the reactor housing 1, i.e. at a point where the polymer sump is located, there is provided between two successive perforated discs 12 or spoked wheels 13 al: least one baffle arrangement 14, 17 and rod-shaped istrippers is. As is to be seen, the reactor is subdivided over its length into three different zones, the spaces between the annular perforated discs 12 or spoked wheels 13 from one another for example varying from zone to zone. This signifies that the spacings of the annular discs 12 in the inlet area ars smaller than in t.he central araa, and these in turn are smaller than In the terminal area. Likewise, the size of the openings 12 in the hollow cylinder 9 increases. The similar discs 12 are provided over their entire cross-section with a plurality of holes, and the spoked wheels have longitudinal and transverse spokes, the size of the holes, i.e. the free cross-section of the annular discs 12 increasing from the front backwards, or the number of spokes 13. also decreasing from zone to ::one. As is to be seen from the last three spoked wheels 13, no further -transverse spokes are present. The alterations need not be undertaken in zones over the length of the reactor, but can be constructed as continuous, AS ia to be seen from the Figure, the annular discs 12 and the spoked wheels 13 are disposed at a:n inclination to the longitudinal axis of the hollow cylinder 9; the angles of incidence can vary, i.e. the angles of incidence become smaller from the inlet of the polymer until its outlet. The angles of incidence are selected in dependence of the material to be processed, and for example like between 0 and 4°, preferably between 0.5 and 2.5°, the diameter also of the discs cr disc rings also however playing a part, what is not to be seen from the drawing is the fact that the annular discs 12 or the spoked wheels 13 are off-set to one another in groups in such a way that their "trace points" lie on a helical or spiral line. In this case the term "trace points" is intended to indicate that point, on the circumference of the discs 12 cr spoked wheels 13 which lias with respect to the disc under consideration nearest to one end wall, and furthest away from the other end wall of the housing 1. Of the discs 12 or spoked wheels 13, one group has for example a plurality of successive discs, and has the same "trace point", whereas the next group, seen in the circumferential direction, has a "trace point" off-set to that of the first group. The angle between the "tracs points" of the successive groups of annular discs is selected in dependence on the desired duration time of the medium in the reactor. The angle of incidence of the discs 12 or spoked wheels 13 may vary in groups or zones. Upon one revolution of the entire group, the nvadium in the vicinity of the group is transported forwards and backwards to a specific part, while another part passes into the vicinity of the next group. In -his way also control of the spectrum of duration times is achieved. The medium to be processed, which takes up approximately 18 to 22% of the overall volume of the reactor, is drawn along by the movement o:f the annular discs 12 or of the spoked wheels 13, and runs off them, threads and free surfaces forming simultaneously at the openings 10 in the hollow cylinder 9, these furthering the reaction. The external di At specific distances apart, seer, over its; length, annular discs 16 are attached in the intemal space of the hollow cylinder 9, said discs en the one hand decelerating the foam from the medium and on the other hand in turn forming drainage members for the medium. According to Figure 2, there is provided behind the first zone a baffle arrangement, made up of disc 17, disposed at an angle of 90° to the longitudinal axis of the hollow cylinder 9, and upon this hollow cylinder, and of a baffle plate 14. The baffle plate 14 is securely connected to the housing l, extends approximately as far as the hollow cylindsr 9, and is arcuate in form. In its outer edge, the disc 17 has perforations 22, and the baffle plate is so disposed that a slot is present between the housing l and the lower edge of the baffle plate 14. The medium is guided by this baffle arrangement 17, 14, and this is a further measure in order to control the spectrum of duration times. Attached in the sump of the medium according to Figure 3, on the housing 1, are the stripper rodis, which are disposed obliquely off-set in the direction of rotation, and are located in the medium. At higher viscosities, these stripper rods 15 avoid the formation of bridges between the spoked wheels 13, and of adhesions, and by means of the flow resisr.anca, in addition, reduce the tendency of the medium, following the direction of rotation, to adopt an oblique configuration. The shape of these stripper rods 15 may be optional; they may for example have a circular or streamline-shaped cross-section. They may also however be so shaped that they reinforce the transport effect on the medium at higher viscosities; for example they may be obliquely angled in the direction of transport. The outlet 5 is in the form of a flattened output cone, thus achieving a more uniform output flow. Moreover, extraction is reinforced by a stirring am and stripper 18, attached to the hollow cylinder 9, and which rotates along with the hollow cylinder 9 and simultaneously strips the end face of the housing l and mixes the medium. Furthermore, the more uniform extraction is improved by the provision of a terminal baffle 19, which is segment - shaped and connected to the housing 1, having a plurality of fine perforations 23 (Figure 4) . The terminal baffle 19 is seesn from its view from the output cone 5. The hollow cylinder 9 is connected at its end by a star connector S:4 comprising strip-shaped plates, to the stub shaft 7. The terminal baffle 9 illustrated prevents an obliquely-positioned level of the medium at the end. This horizontal level enables benter radiation measurement by means of a cobalt rod arrangement, or other measurements in order to ascertain the height of the filling level. The gas extractor nozzle 21 is conical in shape in order to increase the output area, ac that entrainment of particles due to suction effect is reduced. Disposed in the heating jacket 2, and in the upper peak point, there is a pipe circuit 20, through which there flows a heat-transfer medium which is at a higher temperature than the heat-transfer medium of the heating jacket 2. This measure avoids the occurrence of oligomer deposits. EXAMPLE 12 :: The reactor shown in Figure 5 is in particular suitable for higher-viscosity media, it has a basic structure comparable with that shown in Figure 1, a:nd differs particularly in the shapes and arrangemen: of the annular members 12, 13 attached to the ro':or, and in the strippers and baffles attached to the inner side of the housing 1. The housing 1 is provided, like the reactor shown in Figure l, with a heating jacket 2. In this reactor arrangement, this heating jacket is subdivided into three zones along the reactor. AS the medium passes from the inlet 4 to the output cone 5, the polycondensation continues along the reactor. Due to the subdivision of the reactor into at least three zones 29a, 29b and 29c, in aach of these zones, the optimum temperature is set for polycondenisation in this zone. There is located in turn on the upper side of the reactor a pipe circuit 20, through which there flows a heat-transfer medium which is at a higher temperature than the highest of the temperatures in the three heating zones. Thus the deposit of oligomers is prevented in the upper region of the reactor. The inltt 4, the output cone 5 and the gas extractor nozzle 21 are designed and disposed aa in Example 1. In the housing 1 the rotor a is rotatably mounted via the stub shafts 6, 7, the axis of rotation of the rotor 8 in turn being off-set slightly downwards to the longitudinal axis of the housing l. The rotor itself likewise comprises a hollow cylinder 9, attached by a star connector 24 to the stub shaft 7, and shaped as in Example 1. This hollow cylinder also has openings 10 with interposed webs 11, the free cross-saetion of the openings increasing along the flow direction of the medium, Attached or. the external surface of the hallow cylinder 9 or on the webs 11 are annular members. As regards the provision of annular members, the rotor is subdivided into three zones of substantially equal length. in the forward zone, the tumbling discs 12 known from Example 1 are attached at a sllht inclination to the axis of rotation of thi2 rotor 8. in the forward part of the reactor, the viscosity of the medium is still very low. Therefore no stripper reds are provided at that point. Instead of this, scoop members 25 ensure a powerful mixing action of the medium. AS annular members, there are attached to the hollow cylinder 9 in the central region of the rator straight-spoked rings 31 and/straight tubular rings 32, likewise •lightly inclined to the axis of rotation of tha rotor. The tubular rings 32 are partly covered by wire mesh, in order to mix the medium more intensively. Opposite them on the internal side of the housing 1. mounted vertically to the axis of rotation of the rotor, are rod-shaped strippers IS, 27 as shown in Figure 6. These likewise improve the mixing effect of the medium and prevent the formation of polymer bridges between the tubular or spoked rings. As the tubular and spoked rings are inclined with respect to the stripper rods, cleaning of the rings of adhering polymer is not completely effected. in the last portion of the reactor, tubular and/or spoked rings 28 are attached as annular miambers to the external side of the hollow cylinder 9 vertically to the axis of rotation of the rotor. Consequently no transport of the medium is effected by tho annular members in this region. Therefore in thin region the stripper rods are in the form cf a ploughshare 26, as Figure 6 shows. By means cf these ploughuhare-shaped strippers 26, the medium is not only mixed but transported in the direction of the output cone 5. Directly before the output cone 5 there is located a mixer arm with strippers 18 and a grid-shaped output baffle 19, comprising a tubular assembly 30 as in Figure 7. This baffle leads to a decoupling of the medium from the rotary motion of the rotor and -there results a horizontal, measurable level of media, which is independent of the velocity of the rotor or of the transport speed of the transporting members. It has also proved advantageous in this reactor arrangement, for the homogeneity of the polycondensates, to fill approximately 18 - 22% of the reactor volume with medium. WE CLAIM: 1. Reactor device for free-flowing media, particularly for polymers for polycondensation of polyesters, with a horizontally-disposed housing, which has at one end an inlet for supply of medium and at the other end an outlet for its removal, and with a rotor mounted rotatably in the housing via stub shafts, said rotor having annular members for moving and/or transporting the medium, characterised in that the rotor (8) has a hollow cylinder (9) connected to stub shafts (6,7) and provided with openings (10), the annular members (12,13) being attached to the said hollow cylinder (9). 2. Reactor device as claimed in claim 1, wherein the annular members are disposed at least partly inclined with respect to the axis of rotation. 3. Reactor device as claimed in claim 2, wherein the etnnular members are disposed inclined with respect to the axis of rotation in such a way that their trace points form a helical line along the length of the rotor, that point on the circumference of the respective annular member (12,13) being termed a trace point, which has the smallest spacing with respect to one of the two end faces of the housing (1). 4. Reactor device as claimed in claim 3, wherein the free cross-sections and the slot between housing and external diameter of the annular members (12,13) are so selected that the rotating annular members provide a resistance to the free unhindered flow of the medium which is smaller than the transport of the medium achieved by the off-setting of the trace points. 5. Reactor device as claimed in any one of the preceding claims, wherein the angles of incidence of the annular members (12,13) decrease in the direction of transport, i.e. as the viscosity of the medium increases. 6. Reactor device as claimed in any one of the preceding claims, wherein the annular members (12,13) have at least part and in groups the same angle of incidence with respect to the axis of rotation, and/or the same trace point. 7. Reactor device as claimed in any one of the preceding claims, wherein the free cross-sections of the annular members (12,13), and/or the spacings between the annular members, increase in the direction of transport. 8. Reactor device as claimed in any one of the preceding claims, wherein alteration in the angle of incidence and increase in the free cross-sections and of the spacings between the annular members is effected in zones. 9. Reactor device as claimed in any one of the preceding claims, wherein the annular members are in the form of annular discs (12) and/or spoked wheels (13). 1.0. Reactor device as claimed in claim 9, wherein the annular members (12,13) are covered with wire mesh. 11. Reactor device as claimed in any one of the preceding claims, wherein scoop members (25) are attached at least partly and/or in zones between the annular members. 12. Reactor device as claimed in any one of the preceding claims, wherein the openings (10) in the hollow cylinder are rectangular with continuous webs, and the cross-sections of the openings are increased in the flow direction of the medium, preferably in zones. 13. Device as claimed in any one of claims 1 to 7, wherein annular discs (16) are attached as flow decelerating means on the internal circumference of the hollow cylinder (9). 14. Reactor device as claimed in any one of claims 1 to 9, wherein there is disposed in the housing (1) at least one baffle means (14,17) between the annular members (12,13) said baffle means preferably being a baffle plate (14) extending substantially over the entire filling height, and having a disc (17), vertically connected to the hollow cylinders. 15. Reactor device as claimed in any one of the preceding claims, wherein there are attached to the housing (1) in the vicinity of the medium and between the annular members (12,13) preferably in the central or rear region of the rotor, rod-like stripper members (15) serving to avoid adhesion and excessive entrainment of viscous medium between respective pairs of annular members (12,13). 16. Reactor device as claimed in claim 15, wherein the rod-like stripper members (15) have at least in part a shape, preferably similar to that of a ploughshare (26), which reinforces the transport effect. 17. Reactor device as claimed in any one of the preceding claims, wherein the outlet (5) for the medium is in the form of a flattened output cone. 18. Reactor device as claimed in any one of the preceding claims, wherein a terminal baffle (19) is disposed in front of the outlet (5) for the medium, said baffle being substantially disposed over the entire filling height, said terminal baffle (19) preferably either having fine perforations (23) or comprising a tubular assembly (30) 19. Reactor device as claimed in any one of the preceding claims, wherein there is disposed in the output area of the output cone a mixer (18) and stripper, which is connected to the hollow cylinder (9). 20. Reactor device as claimed in any one of the preceding claims, wherein the hollow cylinder (9) is mounted eccentrically in order to increase the gas area to the housing (1). 21. Reactor device as claimed in any one of the preceding claims, wherein the exhaust gas nozzle (21) seen in the direction of transport, is disposed in the rear area of the housing (1) and preferably has a larger, cross-section than the subsequent gas extraction line, in order to reduce the gas output velocity at the gas passage. 22. Reactor device as claimed in any one of the preceding claims, whrein the casing wall is in the form of a heating jacket (2) through which a heat transfer medium flows. 23. Reactor device as claimed in claim 22, wherein the heating jacket (2) is subdivided in the flow direction into a plurality of, preferably three, variably heatable zones (29). 24. Reactor device as claimed in any one of the preceding claims, wherein the upper peak area of the housing (1), there is provided an additional heating zone (20) with a higher temperature than in the reaction chamber, in order to avoid deposits of oligomers. 25. Reactor device as claimed in any one of the preceding claims, wherein the diameter of the hollow cylinder (9) is selected in dependence on the filling level of the medium, the medium taking up approximately 18 - 22% of the overall volume of the housing. 26. Reactor device for free-flowing media substantially as herein described with reference to and as illustrated in the accompanying drawings.

Documents:

2237-del-1995-abstract.pdf

2237-del-1995-claims.pdf

2237-del-1995-complete specifiction (granted).pdf

2237-DEL-1995-Correspondence-Others-(17-03-2011).pdf

2237-del-1995-correspondence-others.pdf

2237-del-1995-correspondence-po.pdf

2237-del-1995-description (complete).pdf

2237-del-1995-drawings.pdf

2237-del-1995-form-1.pdf

2237-del-1995-form-13.pdf

2237-del-1995-form-2.pdf

2237-del-1995-form-3.pdf

2237-del-1995-form-4.pdf

2237-del-1995-form-6.pdf

2237-del-1995-form-9.pdf

2237-DEL-1995-GPA-(17-03-2011).pdf

2237-del-1995-gpa.pdf

2237-del-1995-petition-137.pdf

2237-del-1995-petition-138.pdf