Title of Invention	VACUUM FILTRATION APPARATUS
Abstract	The vacuum filtration apparatus of the present invention provides vacuum trays (16) below a filter cloth (11) provided so as to be able to travel substantially horizontally with respect to an apparatus body (10) and connected to a vacuum apparatus via connection fittings (20), and slurry (S) that is supplied onto the filter cloth (11) and filtered by applying a vacuum through the filter cloth (11) by using the vacuum trays (16). The vacuum trays (16) reciprocate in direction of travel (F) of the filter cloth (11). Each of the plurality of the connection fittings (20) provides elastic vacuum hoses (20B). These vacuum hoses (20B) are disposed so as to extend toward opposite sides with respect to the middle part of the vacuum trays (16) in the transverse direction.

Title of Invention

VACUUM FILTRATION APPARATUS

Abstract

The vacuum filtration apparatus of the present invention provides vacuum trays (16) below a filter cloth (11) provided so as to be able to travel substantially horizontally with respect to an apparatus body (10) and connected to a vacuum apparatus via connection fittings (20), and slurry (S) that is supplied onto the filter cloth (11) and filtered by applying a vacuum through the filter cloth (11) by using the vacuum trays (16). The vacuum trays (16) reciprocate in direction of travel (F) of the filter cloth (11). Each of the plurality of the connection fittings (20) provides elastic vacuum hoses (20B). These vacuum hoses (20B) are disposed so as to extend toward opposite sides with respect to the middle part of the vacuum trays (16) in the transverse direction.

Full Text	VACUUM FILTRATION APPARATUS BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a vacuum filtration apparatus in which slurry supplied onto a filter cloth is filtered by using vacuum trays to apply a vacuum, where the filter cloth may travel substantially horizontally and the vacuum trays are provided under this filter cloth Priority is claimed on Japanese Patent Application No 2004-089346, filed March 25, 2004, the content of which is incorporated herein by reference Description of Related Art An example of this type of vacuum filtration apparatus has been proposed in Citation 1 (Japanese Unexamined Patent Application, First Publication, No S62-79817) and Citation 2 (Japanese Unexamined Patent Application, First Publication, No H07-148404) In these citations, apparatuses are proposed in which an endless belt-shaped filter cloth is hung and wound around a plurality of rollers that are provided on the apparatus body, and this filter cloth can travel continuously in the circumferential direction In these apparatuses, at the portion of the traveling filter cloth that travels horizontally over the upper part of the apparatus body, a plurality of vacuum trays provided under this filter cloth can move reciprocally in the direction of travel of this filter cloth at a predetermined stroke These vacuum trays are each connected to a vacuum apparatus via connection fittings When these vacuum trays advance forward in the direction of travel of the filter cloth, slurry that is supplied onto the filter cloth is filtered due to the vacuum that is applied through this filter cloth by the vacuum apparatus In contiast, when these vacuum trays reach the stroke end, the vacuum is released and the vacuum trays are retracted, subsequently, the operation including the suction and filtration is repeated while the vacuum trays are moved forward again The connection fittings for this type of vacuum filtration apparatus generally are provided with vacuum pipes that are connected to the bottom surface of the vacuum trays and vacuum hoses having a first end connected to the vacuum pipe and a second end connected to the vacuum apparatus The vacuum pipe is directly connected to the bottom surface of the vacuum tray The vacuum hose is formed by an elastic (or flexible) material The second end of the vacuum hose is positioned at one end of the filter cloth in the transverse direction and is connected to the vacuum apparatus side In contrast, the first end of the vacuum hose is positioned at the middle part of a vacuum tray in the transverse direction of the filter cloth The vacuum hoses are disposed below the vacuum trays, and are bent in order to allow the reciprocation of the vacuum trays In the case of a large-scale vacuum filtration apparatus that uses vacuum trays that are long in the transverse direction, by providing a plurality of vacuum pipes spaced at a predetermined interval in the transverse direction, the vacuum from a vacuum tray that is applied to the slurry acts uniformly in the transverse direction and the filtrate from the slurry can be reliably recovered However, in this type of vacuum filtration apparatus, because the elastic vacuum hoses described above are disposed in a bent state, accompanying the reciprocation of the vacuum trays, a restoring forces that act to restore the deformed vacuum hoses to their original state acts on the vacuum trays Therefore, because the vacuum trays are subjected to forces that are transverse to the direction of their movement, the rectilinear stability of the vacuum trays becomes difficult to realize When the restoring forces act on the vacuum trays in this manner, in the case, for example, in which the vacuum trays are supported by a structure in which support wheels are provided that are in contact with both sides of the vacuum trays from the bottom in the transverse direction, uneven wear can occur that causes the vacuum trays to tilt Uneven wear denotes a state in which the amount of wear of the support wheels and the like differs at each side in the transverse direction When the vacuum trays tilt, there is a concern that the travel of the vacuum trays will be obstructed due to uneven movement of the filter cloth In addition, in the case in which, for example, a guide that restricts the vacuum trays along the direction of tiavel is provided on the side surface of the vacuum trays, due to the tilting of the vacuum trays described above, the situation occurs in which the side surface of the vacuum trays scrapes against the guide, and thus there is a concern that obstruction of the travel of the vacuum trays occurs even more easily In particular, in the case of the large-scale vacuum filtration apparatus, the vacuum hoses must have a large diameter because it is necessary to generate a vacuum that is applied to the slurry uniformly in the transverse direction of the vacuum tray, and because the filtrate recovered from the slurry is produced in a large amount However, because the vacuum hoses are bent, the above-described problem in which the travel of the vacuum trays is obstructed becomes severe because the force acting on the vacuum trays becomes larger as the diameter of the vacuum hoses increases Furthermore, when the diameter of the vacuum hoses increases in this manner, the radius of curvature of the vacuum hoses necessarily become large Therefore, there is a problem in that guaranteeing a space to accommodate such vacuum hoses becomes difficult when disposing the vacuum hoses that are in the bent state described above In addition, in a structure in which the vacuum trays are provided in plurality along the direction of travel and the connection fittings are provided on each of these vacuum trays, the interval between the adjacent vacuum hoses becomes small in the direction of travel due to the increase in the diametei of the vacuum hoses Thus, there is a concern that the time for maintenance beneath the vacuum trays will increase In contrast, if the number of the connection fittings is increased and the number of vacuum hoses is increased in order to avoid increasing the diameter of the vacuum hoses, there is a problem in that interference occurs between these hoses and interference occurs between the vacuum hoses and the support wheels In consideration of the problems described above, it is an object of the present invention to provide a vacuum filtration apparatus in which the travel of the vacuum trays is advantageous and reliable SUMMARY OF THE INVENTION In order to attain the objects described above, the vacuum filtration apparatus of the present invention is structured as described below A filter cloth is provided on an apparatus body, which can travel substantially horizontally Under this filter cloth, vacuum trays that are linked to a vacuum apparatus via connection fittings are provided, and these vacuum trays can reciprocate in the direction of the travel of the filter cloth The connection fittings are provided in plurality, and each of these connection fittings provides an elastic vacuum hose These vacuum hoses are disposed so that they extend toward opposite directions from one another with respect to the middle part of the vacuum trays In this apparatus, it is possible to filter slurry supplied onto the filter cloth by applying a vacuum through the filter cloth of the vacuum trays According to this invention, the connection fittings are provided in plurality and the vacuum hoses of each of these connection fittings is arranged so as to extend toward opposite directions from one another with respect to the middle part of the vacuum trays in the transverse direction Thereby, even in the case in which restoring forces are acting on the vacuum trays, where the restonng forces would restore each of the vacuum hoses that are deformed along with the reciprocation of the vacuum trays to their original state, it is possible to cancel these forces each other at the vacuum trays Therefore, it is possible to restrain to a minimum the forces acting on the vacuum trays by the restoring forces of the vacuum hoses in a direction transverse to the direction of travel, it is possible to restrain the occurrence of the situation in which the travel of these vacuum trays is obstructed, and theieby it is possible to realize rectilinear stability of the vacuum trays For example, even in the case in which, in order to support the vacuum trays, support wheels or the like are provided that are in contact from below with both ends of the vacuum trays in the transverse direction, it becomes possible to restrain the occurrence of uneven wear, where the amount of wear of the support wheels or the like differs at each end in the transverse direction, it is possible to restrain the tilt of the vacuum trays, and thereby it is possible to restrain the occurrence of the situation in which the filter cloth easily moves unevenly and the travel of the vacuum tray is obstructed In addition, for example, even in the case in which guides that restrict the vacuum trays in the direction of travel are provided on the side surface of the vacuum trays, because it becomes possible to restrain the tilt of the vacuum trays described above, it is possible to restrain the situation in which the side surfaces are scraped by the guides, and it is possible to restrain the obstruction of the travel of the vacuum trays Furthermore, because the connection fittings are provided in plurality, even if the diameter of the vacuum hoses of these connection fittings is small, it is possible to maintain the vacuum forces that are applied to the slurry from the vacuum trays If the diameter of the vacuum hoses is made small, the restoring force of the vacuum hoses becomes small, and thus it is possible to further and reliably restrain the occurrence of the situation in which the travel of the vacuum trays is obstructed In addition, if the diameter of the vacuum hoses is made small, it becomes possible to implement space saving under these vacuum trays, and it is possible to implement a reduction in the time for maintenance this part Here, the vacuum hoses may be disposed symmetrically with respect to the middle part of the vacuum trays in the transverse direction In this case, the restoring forces due to each of the vacuum hoses acting on the vacuum trays may be reliably cancel, and it is possible to improve even more the rectilinear stability of these vacuum trays It is also possible to connect the vacuum hoses from below to the vacuum trays in a state in which the vacuum hoses are bent so as to form a convexity that is oriented either upstream or downstream with respect to the direction of travel of the filter cloth In this case, it is possible to extend the vacuum hoses in a direction along the surface of the filter cloth or the vacuum trays, it becomes possible to guarantee the space under the vacuum trays, and it becomes possible to restrain an increase in the time for maintenance this part The vacuum hoses may be connected from below to the vacuum trays so as to be separated from each other, where the middle part of the vacuum trays in the transverse direction is situated between the vacuum hoses In this case, below the vacuum trays, because the vacuum hoses do not cross each other, it is possible to prevent reliably the interference between each of the vacuum hoses, and the same time, it is possible to guarantee an even larger space under the vacuum trays It is also possible to configure the plurality of vacuum trays by arranging them in the direction of travel of the filter cloth and to connect the vacuum hoses to each of these vacuum trays from the bottom In this case, since the vacuum hoses have small diameters because the connection fittings are provided in plurality, the interference between adjacent vacuum hoses in the direction of travel is lestrained Therefore, it is possible to implement a reduction in the number and types of parts that form this vacuum filtration apparatus, and it is possible to implement both a reduction in the cost of this apparatus and a reduction in the operation and maintenance costs of this apparatus BRIEF DESCRIPTION OF THE DRAWINGS FIG 1 is a side view showing the entire structure of the embodiment of the vacuum filtration apparatus of the present invention FIG 2 is a plan view of the vacuum filtration apparatus shown in FIG 1 FIG 3 is a cross-sectional drawing viewed along the line A-A of the vacuum filtration apparatus shown in FIG 1 FIG 4 is an enlarged drawing of section B of the vacuum filtration apparatus shown in FIG 3 FIG 5 is a cross-sectional drawing viewed along line the C-C of the vacuum filtration apparatus shown in FIG 3 DETAILED DESCRIPTION OF THE INVENTION FIG 1 through FIG 5 are drawings that show an embodiment of the present invention In the vacuum filtration apparatus of the present embodiment, in an apparatus body 10, an endless belt shaped filter cloth 11 is hung and wound around rollers 12 in succession The upper portion of this filter cloth 11 is disposed so as to extend in the honzontal direction, and this portion serves as a filtration part 11A In addition, among the plurality of rollers 12, a roller 12 A, where the filtei cloth 11 is hung and wound at one end of this filtration part 11A (the right side in FIG 1), is connected to a drive apparatus (not illustrated) The roller 12A is rotated by the drive apparatus in the clockwise direction in the figure, and thereby the filter cloth 11 is also rotated continuously over the rollers 12 Accompanying this rotation, the filtration part 11A of the filter cloth 11 continuously travels in the direction of travel shown by the arrow F in the figuie A slurry supply apparatus 13 that supplies slurry S onto the filter cloth 11 is provided at the other end of the filtration part 11A of the filter cloth 11 (the left side in FIG 1), that is, from above and upstream to the direction of travel F The slurry S that is provided from this slurry supply apparatus 13 onto the filter cloth 11 upside a vacuum tray 16 is filtered by the vacuum applied by the vacuum tray 16 through the filter cloth 11 while being carried in the direction of travel F due to the travel of the filtration part 11A In addition, a cake washing device 21 that supplies a washing fluid L to the filter cloth 11 is provided above the filtration part 11A on the side opposite to that of the slurry supply apparatus 13 in the direction of travel F The washing fluid L is supplied from this cake washing device 21 onto the slurry S that has been vacuum filtered A knife 14 is provided on the roller 12A that drives the filter cloth 11, for pealing off and removing from the filter cloth 11 the dewatered cake of the slurry S, whose filtering and dewatenng has been completed Furthermore, a filter cloth cake washing device 15, which washes the filter cloth 11 after the slurry S has been pealed off by the knife 14, is provided under one end of the filtration part 11A of the filter cloth 11 (the nght side in FIG 1), that is, in the forward direction of travel F Here, the vacuum tray 16 is connected to a vacuum apparatus (not illustrated) by connection fittings 20 A vacuum is applied by the vacuum apparatus through the filter cloth 11 to the slurry S supplied onto the filter cloth 11 The vacuum trays 16 are provided in plurality below the filtration part 11A of the filter cloth 11, starting from substantially directly under the slurry supply apparatus 13 in the forward direction of travel F The connection fittings 20 are connected to each of these vacuum trays 16 from below As shown in FIG 3, each of these vacuum trays 16 has a planar part 16A that extends along the surface of the filter cloth 11 and is in close contact with this filter cloth 11, wall parts 16B that extend upward from the two edges of the planar part 16A in the transverse direction toward the outside in the transverse direction such that both spread, and a reinforcing pipe 17 that is bonded to the planar part 16A from below and extend in the transverse direction Hereafter, among the directions along the surface of the filter cloth 11, the direction that is transverse to the direction of travel F is denoted by the expression "the transverse direction of the vacuum trays 16" As shown in FIG 4, the planar part 16A is a laminated body in which a plate 16C and a mesh body 16D are laminated in this sequence from the bottom The mesh body 16D has a plurality of through holes 16F formed in the surface The filter cloth 11 is in close contact with the surface side of the mesh body 16D As shown in FIG 2, first communicating holes 16E are bored in plurality into the surface of the plate 16C so as to be spaced in the transverse direction of the filter cloth 11 (the vertical direction in FIG 2) Among these first communicating holes 16E, half of the holes are bored so as to be equally spaced from each other in the transverse direction on one side of the middle of the filter cloth 11 in the transverse direction, and the remaining half of the holes are bored so as to be equally spaced from each other on the other side of the middle part in the transverse direction The reinforcing pipes 17 are bonded to each of the plates 16C from below, and are provided so as to extend in the transverse direction of the filter cloth 11, that is, in the transverse direction of the vacuum tray 16 As shown in FIG 5, the cross-sectional shape of the reinforcing pipe 17 is rectangular, and the inside thereof has an inteiioi space 17C that extends in the transverse direction In addition, second communicating holes 17A, which have a diameter smaller than that of the first communicating holes 16E, are bored at positions that are aligned with the positions where the first communicating holes 16E of the plate 16C are bored The upper side of the plate 16C and the interior space 17C of the reinforcing pipe 17 communicate due to the second communicating holes 17A and the first communicating holes 16E As shown in FIG 2, at positions between the innermost pair of the second communicating holes 17A in the transverse direction, two third communicating holes 17B are bored on the bottom surface of the reinforcing pipe 17 at opposite positions, where the middle of the filter cloth 11 in the transverse direction is situated therebetween As shown in FIG 2 and FIG 5, reinforcing members (for example, channel members) 17D that extend in the direction of travel F of the filter cloth 11 are provided between one set of the adjacent reinforcing pipes 17 in the direction of travel F of the filter cloth 11 These channel members 17D are bonded to the bottom surface of the plates 16C and the side surface of the reinforcing pipes 17 As shown in FIG 3 and FIG 5, a connection fitting 20 is provided with a vacuum pipe 20A that is connected to the third communicating hole 17B of the reinforcing pipe 17 and extends downward, and a vacuum hose 20B that has one end connected to the bottom end of the vacuum pipe 20 A and the other end connected to the vacuum apparatus (not illustrated) The vacuum pipe 20 A is formed by a rigid tube of, for example, stainless steel The vacuum hose 20B is formed by an elastic or flexible material, such as ethylene-propylene rubber These connection fittings 20 are provided in plurality (two in the present embodiment) on one vacuum tray 16 Below the vacuum tray 16, these connection fittings 20 are disposed opposite to each other so as to be symmetrical in the transverse direction with respect to the middle of the filter cloth 11, where the middle part of the filter cloth 11 in the transverse direction is situated therebetween As shown in FIG 2, each of the vacuum hoses 20B extends in the transverse direction of the filter cloth 11 from the middle part of the filter cloth 11 so as to separate from each other In addition, as shown in FIG 3, the portion of the vacuum hoses 20B between one end and the other end is mounted so as to be able to slide on rail-shaped support members 20C which extend in the direction of travel F This portion is substantially parallel to the surface of the filter cloth 11 below the vacuum trays 16, and is curved such that the convexity is oriented in the forward direction of travel F of the filter cloth 11 By mounting the vacuum hoses 20B in this manner, they are supported in a state that permits reciprocating along the direction of travel F Sliding members 20D are attached at the portions of the vacuum hoses 20B that are in contact with the support members 20C These sliding members 20D are made of a material that the coefficient of friction to the support members 20C is small and has a superior wear resistance, such as ultrahigh molecular weight polyethylene Here, the two connection fittings 20 disposed opposite to each other in the transverse direction are disposed so that each of their vacuum pipes 20 A is substantially identically positioned with respect to the direction of travel F In addition, large diameter suction pipes (not illustrated) that extend parallel to the direction of travel F are provided on the both sides of the apparatus body 10m the transverse direction The other ends of the vacuum hoses 20B of the two connection fittings 20 are each connected to the suction pipes Via these suction pipes, the connection fittings 20 are connected to the vacuum apparatus In the vacuum filtration apparatus described above, by activating the vacuum apparatus, a vacuum force is applied to the mesh body 16D, which serves as the vacuum chamber, through the vacuum hoses 20B, the vacuum pipes 20A, the reinforcing pipes 17, and the first communicating holes 16E of the plate 16C, and thereby the vacuum force is applied to the slurry S on the filter cloth 11 Due to this vacuum force, the liquid portion of the slurry S on the filter cloth 11 is recovered through the filter cloth 11 in succession through the mesh body 16D, the first communicating holes 16E of the plate 16C, the reinforcing pipes 17, the vacuum pipes 20A, and the vacuum hoses 2 OB In the vacuum chamber (mesh body 16D), the vacuum is released by switching the vent mechanism of the vacuum apparatus to return to atmospheric pressure The vacuum trays 16 that are adjacent to each other in the direction of travel F are connected together Among these vacuum trays 16, as shown in FIG 1, a drive cylinder 18, such as an air cylinder, is installed on a frame 10A of the apparatus body 10 The drive cylinder 18 expands and contracts along the direction of travel F and is connected to the vacuum tray 16, which is positioned farthest upstream with respect to the direction of travel F Due to the expansion and contraction of the drive cylinder 18, all of the vacuum trays 16 may move reciprocally together at a predetermined stroke in both the forward and reverse direction of travel F, that is, may move reciprocally along this direction of travel F Along with the forward and reverse movement of the vacuum trays 16, the vacuum hoses 20B, whose second ends are connected to the vacuum apparatus, bend by deforming elastically, and the connection fittings 20 move reciprocally as a whole As shown in FIG 1 and FIG 3, freely rotating support wheels 19 that support the vacuum trays 16 are provided in plurality on the apparatus body 10, and these support wheels 19 are spaced in the transverse direction of the filter cloth 11 The support wheels 19 contact from below a pair of rails 22 that are provided below both ends of the vacuum trays 16 in the transverse direction and extend in the direction of travel F The vacuum trays 16 may reciprocate on these freely lotating support wheels 19 Contrariwise, the support wheels 19 are caused to rotate by the reciprocation of the vacuum trays 16 by the drive cylinder 18 These support wheels 19, which are all the same shape and same size, are installed so as to be able to rotate freely around a horizontal axis of rotation that extends in the transverse direction via brackets and the like that are provided facing upward on the frame 10A of the apparatus body 10 A support wheel 19 may have a disc shape or a columnar shape with a short axle length, and is centered on this axis of rotation The support wheels 19 are arranged so as to form two parallel rows that extend in the direction of travel F along both edges of the bottom surface of the vacuum trays 16 in the transverse direction The support wheels 19 in each row are disposed at equal intervals in the direction of travel F At the same time, the support wheels 19 in each of the rows align to form pairs in the transverse direction, and the support wheels 19 that form pairs have equal heights in the vertical direction and are disposed at identical positions in the direction of travel F According to the vacuum filtration apparatus in the present embodiment described above, the connection fittings 20 are provided in plurality, and the vacuum hoses 20B of each of the connection fittings 20 are arranged so that they extend toward opposite sides with respect to the middle part of the vacuum tray 16 in the transverse direction Therefore, each of the vacuum hoses 20B deforms along with the reciprocation of the vacuum tray 16, and even when the restoring forces that would restore the vacuum hoses 20B act on the vacuum tray 16, it is possible to cancel these forces each other at the vacuum tray 16 Therefore, due to the restoring forces of the vacuum hoses 20B, it is possible to restrain to a minimum the forces acting on the vacuum tray 16 in the direction crossing the direction of travel At the same time, it is possible to restrain to a minimum the moment of rotation that causes the vacuum tray 16 to wobble along the surface of the planar part 16A That is, it is possible to restrain the occurrence of the situation in which the travel of the vacuum trays 16 is obstructed, and it is possible to realize the rectilinear stability of the vacuum trays 16 Thereby, as in the present embodiment, even in a structure in which the apparatus body 10 provides both a pair of rails 22 that extend in the direction of travel F under both ends of the vacuum trays 16 in the transverse direction and the support wheels 19 that are arranged on the rails 22 and support the vacuum trays 16 by contacting from below, it is possible to restrain the occurrence of uneven wear, in which the amount of wear of the rails 22 and the support wheels 19 differs on each edge in the transverse direction It is also possible to restrain the tilting of the vacuum trays 16 and it is possible to restrain the occurrence of the situation in which the filter cloth 11 easily moves unevenly and the travel of the vacuum trays 16 is obstructed In addition to this, even in the case in which, for example, guides are provided that restrict the side surface of the vacuum trays 16 in the direction of travel, it is possible to restrain the tilting of the vacuum trays 16 described above Thereby, it is possible to restrain the obstruction of the travel of the vacuum trays 16 due to the situation in which the guide scrapes the side surface of the vacuum trays 16 Furthermore, because the connection fittings 20 are provided in plurality, it is possible to maintain the vacuum force from the vacuum tray 16 on the slurry S even if the diameter of the vacuum hoses 20B of these connection fittings 20 is made small In this case, because the restoring force of the vacuum hoses 20B becomes small, it is possible to further restrain reliably the occurrence of the situation described above, in which the travel of the vacuum tray 16 is obstructed, and at the same time, it becomes possible to implement space saving below the vacuum trays 16 and it becomes possible to implement reductions in the time for maintenance this part Here, in the present embodiment, because the vacuum hoses 20B are disposed symmetrically with respect to the middle of a vacuum tray 16 in the transverse direction, the restoring force due to each of the vacuum hoses 20B acting on the vacuum tray 16 may be reliably cancel, and it is possible to improve significantly the rectilinear stability of these vacuum trays 16 In addition, because the vacuum hoses 20B are connected from below to the vacuum trays 16 in a bent state so as to form a convexity oriented downstream to the direction of travel F of the filter cloth 11, the vacuum hoses 20B extend in the direction along the surface of the filter cloth 11 and the vacuum trays 16 Therefore, it becomes possible to guarantee the space below the vacuum trays 16 and it becomes possible to restrain an increase in the time for maintenance in this part Furthermore, because the vacuum hoses 20B are connected to the vacuum trays 16 from the bottom thereof so as to be separated from each other, where the middle part of the vacuum trays 16 in the transverse direction is situated therebetween, the vacuum hoses 20B will never cross each other under the vacuum trays 16 Therefore, it becomes possible to avoid interference between each of the vacuum hoses 20B reliably, and at the same time, it is possible to guarantee an even larger space below the vacuum trays 16 Furthermore, because the plurality of the vacuum trays 16 are configured by being arranged in the direction of travel F of the filter cloth 11 and the vacuum hoses 20B are connected to each of these vacuum trays 16 from below, by making the diameter of the vacuum hoses 20B smaller by providing the connection fittings 20 in plurality, it is possible to restrain the interference between the adjacent vacuum hoses 20B in the direction of travel F, it is possible to implement a reduction in the number of types of parts that form this vacuum filtration apparatus, and it is possible to reduce costs and implement reductions in the operation and maintenance costs As described above, the present embodiment lllustiates a structure for a vacuum filtration apparatus in which the plurality of the vacuum trays 16 are configured by being arranged in the direction of travel F of the filter cloth 11 and the connection fittings 20 are connected to each of the vacuum trays 16 from below In tins case, the problem may be anticipated in which the space under the vacuum trays 16 is narrowed and thereby interference might occur between the adjacent vacuum hoses 20B in the direction of travel F However, in the present embodiment, as described above because the diameter of the vacuum hoses 20B may be made smaller by providing the connection fittings 20 in plurality, it is possible to guarantee the space under the vacuum trays 16 and prevent interference between the vacuum hoses 20B, and it is also possible to prevent an increase in the time for maintenance At the same time, it is possible to reduce the number and types of parts that form this vacuum filtration apparatus Thus, it is possible to implement reductions in the cost of this apparatus and reductions in the operation and maintenance costs In addition, because the reinforcing pipes 17, which are bonded to bottom of the vacuum trays 16 and extend in the transverse direction of the filter cloth 11, are provided with a rib shape, the rigidity of the vacuum trays 16 that withstands deformation due to external forces may be increased Therefore, even in the case in which the restoring forces due to the vacuum hoses 20B act on the planar part 16A of the vacuum trays 16 to deform this planar part 16A, a rigidity that may withstand these restoring forces may be provided to the planar part 16 A Therefore, it is possible to prevent the obstruction of the travel of the vacuum trays 16 reliably, and at the same time, it is possible to restrain the occurrence of uneven movement of the filter cloth 11 Furthermore, the vacuum pipes 20 A aie connected to the bottom surface of the plate 16C of the vacuum tray 16 via the reinforcing pipes 17, which have a higher rigidity than that of this plate 16C that withstands deformation Therefore, even in the case in which the connection part between the vacuum pipes 20A and the vacuum tray 16 is repeatedly subjected to a load due to either the travel of the vacuum trays 16 during the use of this vacuum filtration apparatus or the restoring forces of the vacuum hoses 20B, it is possible to restrain the occurrence of breakage to this connecting part Specifically, in the case in which a vacuum pipe 20A is directly connected to a plate 16C that has a low rigidity for withstanding the deformation due to external forces, the plate 16C easily deforms due to the restoring forces of the vacuum hoses 20B, and residual stresses due to the repeated reciprocal travel of the vacuum trays 16 accumulate easily Thus, the load acting on the connecting part becomes large and this connecting part becomes comparatively easy to damage In contrast, as in the case of the present embodiment, when the vacuum pipes 20 A are connected to the reinforcing pipes 17, whose rigidity for withstanding the deformation due to an external force is comparatively high, the restoring forces of the vacuum hoses 20B act on the reinforcing pipes 17, and do not directly act on the vacuum trays 16 Because the reinforcing pipe 17 itself is very rigid, the deformation due to the restoring forces and the accumulation of the residual stresses may be restrained Therefore, the occurrence of damage to the connecting part between the vacuum pipes 20A and the bottom surface of the plate 16C may be restrained, and thereby it is also possible to realize both an increase in the service life of the vacuum filtration apparatus and a reduction in the time for maintenance the vacuum filtration apparatus In the case of a large-scale vacuum filtration apparatus having the filter cloth 11 whose width is equal to or greater than 2500 mm, the amount of the filtrate recovered from the slurry S is increased of course, and it is required that the vacuum force applied to the slurry S be uniform for a short period of time in the transverse direction of the vacuum trays 16 In order to attain this, it is possible to consider using a structure in which the vacuum pipes 20A are provided in plurality so as to be spaced in the transverse direction on the bottom surface of the plate 16C that forms the vacuum tray 16, connecting pipes that connect these vacuum pipes 20A together are disposed, and one vacuum hose 20B is connected to this connecting pipe However, in this type of structure, due to the restoring forces of the vacuum hoses 20B, forces will act similarly on the connecting pipe as well, and the restoring forces act on the bottom surface of the plate 16C from each of the of vacuum pipes 20 A that are connected in plurality to this connecting pipe Thus, there is the concern that further deformation to the plate 16C may occur easily and that this will contribute both to the obstruction of the travel of the vacuum trays 16 and the shortening of the service life of the vacuum filtration apparatus However, in the present embodiment, the reinforcing pipes 17 that have a higher rigidity for withstanding the deformation than that of the plate 16C are provided on the bottom surface of this plate 16C The second communicating holes 17A are bored in plurality in the upper surface of these reinforcing pipes 17 so as to be spaced in the transverse direction of the vacuum trays 16 Also, the third communicating holes 17B that communicate with the vacuum pipe 20 A are bored in the bottom surfaces of the reinforcing pipes 17, and these third communicating holes 17B communicate with the vacuum apparatus Therefore, among the vacuum trays 16, when locations at which a vacuum force is applied to the vacuum chamber (mesh body 16D) of the vacuum trays 16 are provided in plurality, it is possible to limit the locations at which the restoring forces of the vacuum hoses 20B are directly acting to the reinforcing pipes 17 which have a comparatively high rigidity Furthermore, in a structure that uses the connecting pipes, for one connection fitting 20, the part that connects the plate 16C must be provided at two or more locations However, in the present embodiment, it is possible to limit this type of connecting part to one location for one connection fitting 20 Specifically, in the present embodiment, the interior spaces 17C of the reinforcing pipes 17 for reinforcing the vacuum trays 16 apply a vacuum force to these vacuum trays 16 and at the same time double as flow paths for recovering the filtrate In addition, even if an unevenness in the strength of the vacuum force occurs between the plurality of the vacuum pipes 20A and the vacuum hoses 20B, due to the presence of these reinforcing pipes 17 (interior spaces 17C), it is possible to apply a vacuum force uniformly to the vacuum chamber from the plurality of the second communicating holes 17A Therefore, in the large-scale vacuum filtration apparatus, it becomes possible to produce the vacuum force evenly for a short period of time in the transverse direction of the vacuum trays 16 That is, in this type of structure as well, it is possible to restrain the occurrence of deformation in the plate 16C reliably, and it is possible to restrain reliably both the obstruction of the travel of the vacuum trays 16 and the reduction in the service life of the vacuum filtration apparatus While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting Additions, omissions, substitutions, and other modifications may be made without departing from the spirit or scope of the present invention Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims For example, the direction of the convexity of the curved shape of the vacuum hoses 20B may be downstream to the direction of travel F In addition, the vacuum hoses 20B should be disposed so as to extend to opposite sides with respect to the middle part in the transverse direction of the vacuum tray 16 at least For example, the vacuum hoses 20B are not limited to being connected to the bottom of the vacuum tray 16, and they may be connected to the side thereof In the structure in which the vacuum hoses 20B are connected to the bottom of the vacuum tray 16, the vacuum hoses 20B may be disposed such that the vacuum hoses 20B cross each other along the extension from the connection with the vacuum tray 16 In addition, the number of the vacuum hoses 20B connected to one vacuum tray 16, the connection positions and the like are not limited by the embodiments As long as the restonng forces acting on the vacuum trays 16 due to each of the vacuum hoses 20B that accompanies the reciprocation of the vacuum tray 16 are cancel, the material of the vacuum hose 20B, external diameter of the vacuum hose 20B, the positions of the connection between the vacuum hoses 20B and the vacuum tray 16, and the like may be altered by appropriate selection The structure is not hmited to which the vacuum tray 16 provides the reinforcing pipes 17, the vacuum pipes 20 A may be directly connected to the bottom surface of the plate 16C without interposing the reinforcing pipes 17 therebetween The entire vacuum hoses 20B that are connected to the plurality of vacuum trays 16 may be connected to one vacuum apparatus Alternatively, the vacuum hoses 20B connected to each or the plurality of the vacuum trays 16 may be connected to different vacuum apparatuses respectively We claim: 1. A vacuum filtration apparatus for filtering slurry (S) by a vacuum, Comprising: an apparatus body (10); a filter cloth (11) to be supplied with the slurry (s), that travels substantially horizontally with respect to the apparatus body (10); a vacuum tray (16) disposed under the filter cloth (11) and reciprocated in direction of travel (F) of the filter cloth (11); vacuum hoses (20B) having elasticity, ends of at least two of the vacuum hoses (20B) being connected to the vacuum try (16) so as the transversely extend in opposite directions with respect to the middle of the vacuum tray (16), and the other ends thereof being connected to a vacuum apparatus which applies a vacuum to the slurry (S) through the filter cloth (11) and the vacuum tray (16). 2. A vacuum filtration apparatus as claimed in claim 1, wherein the vacuum hoses (20 B) are disposed symmetrically with respect to the middle of the vacuum tray (16) in the transverse direction. 3. A vacuum filtration apparatus as claimed in claim 1, wherein the vacuum hoses (20B) connect to the vacuum tray (16) from below in a bent state so as the form a convexity in the upstream or downstream direction of travel (F) of the filter cloth (11). 4. A vacuum filtration apparatus as claimed in claim 1, wherein the vacuum hoses (20B) are connected to the vacuum tray (16) from below, and are separated from each other, where the middle part of the filter cloth (11) in the transverse direction is situated therebetween. 5. A vacuum filtration apparatus as claimed in claim 1, wherein a plurality of the vacuum trays (16) are arranged in the direction of travel (F) of the filter cloth (11), and the vacuum hoses (20B) are connected from below to each of the vacuum trays (16).

Full Text

VACUUM FILTRATION APPARATUS
BACKGROUND OF THE INVENTION Field of the Invention
The present invention relates to a vacuum filtration apparatus in which slurry supplied onto a filter cloth is filtered by using vacuum trays to apply a vacuum, where the filter cloth may travel substantially horizontally and the vacuum trays are provided under this filter cloth
Priority is claimed on Japanese Patent Application No 2004-089346, filed March 25, 2004, the content of which is incorporated herein by reference
Description of Related Art
An example of this type of vacuum filtration apparatus has been proposed in Citation 1 (Japanese Unexamined Patent Application, First Publication, No S62-79817) and Citation 2 (Japanese Unexamined Patent Application, First Publication, No H07-148404) In these citations, apparatuses are proposed in which an endless belt-shaped filter cloth is hung and wound around a plurality of rollers that are provided on the apparatus body, and this filter cloth can travel continuously in the circumferential direction In these apparatuses, at the portion of the traveling filter cloth that travels horizontally over the upper part of the apparatus body, a plurality of vacuum trays provided under this filter cloth can move reciprocally in the direction of travel of this filter cloth at a predetermined stroke These vacuum trays are each connected to a vacuum apparatus via connection fittings When these vacuum trays advance forward in the direction of travel of the filter cloth, slurry that is supplied onto the filter cloth is filtered due to the vacuum that is applied through this filter cloth by the vacuum

apparatus In contiast, when these vacuum trays reach the stroke end, the vacuum is released and the vacuum trays are retracted, subsequently, the operation including the suction and filtration is repeated while the vacuum trays are moved forward again
The connection fittings for this type of vacuum filtration apparatus generally are provided with vacuum pipes that are connected to the bottom surface of the vacuum trays and vacuum hoses having a first end connected to the vacuum pipe and a second end connected to the vacuum apparatus
The vacuum pipe is directly connected to the bottom surface of the vacuum tray The vacuum hose is formed by an elastic (or flexible) material The second end of the vacuum hose is positioned at one end of the filter cloth in the transverse direction and is connected to the vacuum apparatus side In contrast, the first end of the vacuum hose is positioned at the middle part of a vacuum tray in the transverse direction of the filter cloth The vacuum hoses are disposed below the vacuum trays, and are bent in order to allow the reciprocation of the vacuum trays In the case of a large-scale vacuum filtration apparatus that uses vacuum trays that are long in the transverse direction, by providing a plurality of vacuum pipes spaced at a predetermined interval in the transverse direction, the vacuum from a vacuum tray that is applied to the slurry acts uniformly in the transverse direction and the filtrate from the slurry can be reliably recovered
However, in this type of vacuum filtration apparatus, because the elastic vacuum hoses described above are disposed in a bent state, accompanying the reciprocation of the vacuum trays, a restoring forces that act to restore the deformed vacuum hoses to their original state acts on the vacuum trays Therefore, because the vacuum trays are subjected to forces that are transverse to the direction of their movement, the rectilinear stability of the vacuum trays becomes difficult to realize

When the restoring forces act on the vacuum trays in this manner, in the case, for example, in which the vacuum trays are supported by a structure in which support wheels are provided that are in contact with both sides of the vacuum trays from the bottom in the transverse direction, uneven wear can occur that causes the vacuum trays to tilt Uneven wear denotes a state in which the amount of wear of the support wheels and the like differs at each side in the transverse direction When the vacuum trays tilt, there is a concern that the travel of the vacuum trays will be obstructed due to uneven movement of the filter cloth In addition, in the case in which, for example, a guide that restricts the vacuum trays along the direction of tiavel is provided on the side surface of the vacuum trays, due to the tilting of the vacuum trays described above, the situation occurs in which the side surface of the vacuum trays scrapes against the guide, and thus there is a concern that obstruction of the travel of the vacuum trays occurs even more easily
In particular, in the case of the large-scale vacuum filtration apparatus, the vacuum hoses must have a large diameter because it is necessary to generate a vacuum that is applied to the slurry uniformly in the transverse direction of the vacuum tray, and because the filtrate recovered from the slurry is produced in a large amount However, because the vacuum hoses are bent, the above-described problem in which the travel of the vacuum trays is obstructed becomes severe because the force acting on the vacuum trays becomes larger as the diameter of the vacuum hoses increases Furthermore, when the diameter of the vacuum hoses increases in this manner, the radius of curvature of the vacuum hoses necessarily become large Therefore, there is a problem in that guaranteeing a space to accommodate such vacuum hoses becomes difficult when disposing the vacuum hoses that are in the bent state described above
In addition, in a structure in which the vacuum trays are provided in plurality along the direction of travel and the connection fittings are provided on each of these

vacuum trays, the interval between the adjacent vacuum hoses becomes small in the direction of travel due to the increase in the diametei of the vacuum hoses Thus, there is a concern that the time for maintenance beneath the vacuum trays will increase In contrast, if the number of the connection fittings is increased and the number of vacuum hoses is increased in order to avoid increasing the diameter of the vacuum hoses, there is a problem in that interference occurs between these hoses and interference occurs between the vacuum hoses and the support wheels
In consideration of the problems described above, it is an object of the present invention to provide a vacuum filtration apparatus in which the travel of the vacuum trays is advantageous and reliable
SUMMARY OF THE INVENTION
In order to attain the objects described above, the vacuum filtration apparatus of the present invention is structured as described below A filter cloth is provided on an apparatus body, which can travel substantially horizontally Under this filter cloth, vacuum trays that are linked to a vacuum apparatus via connection fittings are provided, and these vacuum trays can reciprocate in the direction of the travel of the filter cloth The connection fittings are provided in plurality, and each of these connection fittings provides an elastic vacuum hose These vacuum hoses are disposed so that they extend toward opposite directions from one another with respect to the middle part of the vacuum trays In this apparatus, it is possible to filter slurry supplied onto the filter cloth by applying a vacuum through the filter cloth of the vacuum trays
According to this invention, the connection fittings are provided in plurality and the vacuum hoses of each of these connection fittings is arranged so as to extend toward opposite directions from one another with respect to the middle part of the vacuum trays

in the transverse direction Thereby, even in the case in which restoring forces are acting on the vacuum trays, where the restonng forces would restore each of the vacuum hoses that are deformed along with the reciprocation of the vacuum trays to their original state, it is possible to cancel these forces each other at the vacuum trays Therefore, it is possible to restrain to a minimum the forces acting on the vacuum trays by the restoring forces of the vacuum hoses in a direction transverse to the direction of travel, it is possible to restrain the occurrence of the situation in which the travel of these vacuum trays is obstructed, and theieby it is possible to realize rectilinear stability of the vacuum trays For example, even in the case in which, in order to support the vacuum trays, support wheels or the like are provided that are in contact from below with both ends of the vacuum trays in the transverse direction, it becomes possible to restrain the occurrence of uneven wear, where the amount of wear of the support wheels or the like differs at each end in the transverse direction, it is possible to restrain the tilt of the vacuum trays, and thereby it is possible to restrain the occurrence of the situation in which the filter cloth easily moves unevenly and the travel of the vacuum tray is obstructed In addition, for example, even in the case in which guides that restrict the vacuum trays in the direction of travel are provided on the side surface of the vacuum trays, because it becomes possible to restrain the tilt of the vacuum trays described above, it is possible to restrain the situation in which the side surfaces are scraped by the guides, and it is possible to restrain the obstruction of the travel of the vacuum trays Furthermore, because the connection fittings are provided in plurality, even if the diameter of the vacuum hoses of these connection fittings is small, it is possible to maintain the vacuum forces that are applied to the slurry from the vacuum trays If the diameter of the vacuum hoses is made small, the restoring force of the vacuum hoses becomes small, and thus it is possible to further and reliably restrain the occurrence of

the situation in which the travel of the vacuum trays is obstructed In addition, if the diameter of the vacuum hoses is made small, it becomes possible to implement space saving under these vacuum trays, and it is possible to implement a reduction in the time for maintenance this part Here, the vacuum hoses may be disposed symmetrically with respect to the middle part of the vacuum trays in the transverse direction In this case, the restoring forces due to each of the vacuum hoses acting on the vacuum trays may be reliably cancel, and it is possible to improve even more the rectilinear stability of these vacuum trays
It is also possible to connect the vacuum hoses from below to the vacuum trays in a state in which the vacuum hoses are bent so as to form a convexity that is oriented either upstream or downstream with respect to the direction of travel of the filter cloth In this case, it is possible to extend the vacuum hoses in a direction along the surface of the filter cloth or the vacuum trays, it becomes possible to guarantee the space under the vacuum trays, and it becomes possible to restrain an increase in the time for maintenance this part
The vacuum hoses may be connected from below to the vacuum trays so as to be separated from each other, where the middle part of the vacuum trays in the transverse direction is situated between the vacuum hoses In this case, below the vacuum trays, because the vacuum hoses do not cross each other, it is possible to prevent reliably the interference between each of the vacuum hoses, and the same time, it is possible to guarantee an even larger space under the vacuum trays
It is also possible to configure the plurality of vacuum trays by arranging them in the direction of travel of the filter cloth and to connect the vacuum hoses to each of these vacuum trays from the bottom In this case, since the vacuum hoses have small diameters because the connection fittings are provided in plurality, the interference

between adjacent vacuum hoses in the direction of travel is lestrained Therefore, it is possible to implement a reduction in the number and types of parts that form this vacuum filtration apparatus, and it is possible to implement both a reduction in the cost of this apparatus and a reduction in the operation and maintenance costs of this apparatus
BRIEF DESCRIPTION OF THE DRAWINGS FIG 1 is a side view showing the entire structure of the embodiment of the
vacuum filtration apparatus of the present invention
FIG 2 is a plan view of the vacuum filtration apparatus shown in FIG 1 FIG 3 is a cross-sectional drawing viewed along the line A-A of the vacuum
filtration apparatus shown in FIG 1
FIG 4 is an enlarged drawing of section B of the vacuum filtration apparatus
shown in FIG 3
FIG 5 is a cross-sectional drawing viewed along line the C-C of the vacuum
filtration apparatus shown in FIG 3
DETAILED DESCRIPTION OF THE INVENTION FIG 1 through FIG 5 are drawings that show an embodiment of the present invention In the vacuum filtration apparatus of the present embodiment, in an apparatus body 10, an endless belt shaped filter cloth 11 is hung and wound around rollers 12 in succession The upper portion of this filter cloth 11 is disposed so as to extend in the honzontal direction, and this portion serves as a filtration part 11A In addition, among the plurality of rollers 12, a roller 12 A, where the filtei cloth 11 is hung and wound at one end of this filtration part 11A (the right side in FIG 1), is connected to a drive apparatus (not illustrated) The roller 12A is rotated by the drive apparatus in the

clockwise direction in the figure, and thereby the filter cloth 11 is also rotated continuously over the rollers 12 Accompanying this rotation, the filtration part 11A of the filter cloth 11 continuously travels in the direction of travel shown by the arrow F in the figuie
A slurry supply apparatus 13 that supplies slurry S onto the filter cloth 11 is provided at the other end of the filtration part 11A of the filter cloth 11 (the left side in FIG 1), that is, from above and upstream to the direction of travel F The slurry S that is provided from this slurry supply apparatus 13 onto the filter cloth 11 upside a vacuum tray 16 is filtered by the vacuum applied by the vacuum tray 16 through the filter cloth 11 while being carried in the direction of travel F due to the travel of the filtration part 11A In addition, a cake washing device 21 that supplies a washing fluid L to the filter cloth 11 is provided above the filtration part 11A on the side opposite to that of the slurry supply apparatus 13 in the direction of travel F The washing fluid L is supplied from this cake washing device 21 onto the slurry S that has been vacuum filtered A knife 14 is provided on the roller 12A that drives the filter cloth 11, for pealing off and removing from the filter cloth 11 the dewatered cake of the slurry S, whose filtering and dewatenng has been completed Furthermore, a filter cloth cake washing device 15, which washes the filter cloth 11 after the slurry S has been pealed off by the knife 14, is provided under one end of the filtration part 11A of the filter cloth 11 (the nght side in FIG 1), that is, in the forward direction of travel F Here, the vacuum tray 16 is connected to a vacuum apparatus (not illustrated) by connection fittings 20 A vacuum is applied by the vacuum apparatus through the filter cloth 11 to the slurry S supplied onto the filter cloth 11 The vacuum trays 16 are provided in plurality below the filtration part 11A of the filter cloth 11, starting from substantially directly under the slurry supply apparatus 13 in the

forward direction of travel F The connection fittings 20 are connected to each of these vacuum trays 16 from below
As shown in FIG 3, each of these vacuum trays 16 has a planar part 16A that extends along the surface of the filter cloth 11 and is in close contact with this filter cloth 11, wall parts 16B that extend upward from the two edges of the planar part 16A in the transverse direction toward the outside in the transverse direction such that both spread, and a reinforcing pipe 17 that is bonded to the planar part 16A from below and extend in the transverse direction
Hereafter, among the directions along the surface of the filter cloth 11, the direction that is transverse to the direction of travel F is denoted by the expression "the transverse direction of the vacuum trays 16"
As shown in FIG 4, the planar part 16A is a laminated body in which a plate 16C and a mesh body 16D are laminated in this sequence from the bottom The mesh body 16D has a plurality of through holes 16F formed in the surface The filter cloth 11 is in close contact with the surface side of the mesh body 16D As shown in FIG 2, first communicating holes 16E are bored in plurality into the surface of the plate 16C so as to be spaced in the transverse direction of the filter cloth 11 (the vertical direction in FIG 2) Among these first communicating holes 16E, half of the holes are bored so as to be equally spaced from each other in the transverse direction on one side of the middle of the filter cloth 11 in the transverse direction, and the remaining half of the holes are bored so as to be equally spaced from each other on the other side of the middle part in the transverse direction
The reinforcing pipes 17 are bonded to each of the plates 16C from below, and are provided so as to extend in the transverse direction of the filter cloth 11, that is, in the transverse direction of the vacuum tray 16 As shown in FIG 5, the cross-sectional

shape of the reinforcing pipe 17 is rectangular, and the inside thereof has an inteiioi space 17C that extends in the transverse direction In addition, second communicating holes 17A, which have a diameter smaller than that of the first communicating holes 16E, are bored at positions that are aligned with the positions where the first communicating holes 16E of the plate 16C are bored The upper side of the plate 16C and the interior space 17C of the reinforcing pipe 17 communicate due to the second communicating holes 17A and the first communicating holes 16E As shown in FIG 2, at positions between the innermost pair of the second communicating holes 17A in the transverse direction, two third communicating holes 17B are bored on the bottom surface of the reinforcing pipe 17 at opposite positions, where the middle of the filter cloth 11 in the transverse direction is situated therebetween As shown in FIG 2 and FIG 5, reinforcing members (for example, channel members) 17D that extend in the direction of travel F of the filter cloth 11 are provided between one set of the adjacent reinforcing pipes 17 in the direction of travel F of the filter cloth 11 These channel members 17D are bonded to the bottom surface of the plates 16C and the side surface of the reinforcing pipes 17
As shown in FIG 3 and FIG 5, a connection fitting 20 is provided with a vacuum pipe 20A that is connected to the third communicating hole 17B of the reinforcing pipe 17 and extends downward, and a vacuum hose 20B that has one end connected to the bottom end of the vacuum pipe 20 A and the other end connected to the vacuum apparatus (not illustrated) The vacuum pipe 20 A is formed by a rigid tube of, for example, stainless steel The vacuum hose 20B is formed by an elastic or flexible material, such as ethylene-propylene rubber
These connection fittings 20 are provided in plurality (two in the present embodiment) on one vacuum tray 16 Below the vacuum tray 16, these connection fittings 20 are disposed opposite to each other so as to be symmetrical in the transverse

direction with respect to the middle of the filter cloth 11, where the middle part of the filter cloth 11 in the transverse direction is situated therebetween As shown in FIG 2, each of the vacuum hoses 20B extends in the transverse direction of the filter cloth 11 from the middle part of the filter cloth 11 so as to separate from each other In addition, as shown in FIG 3, the portion of the vacuum hoses 20B between one end and the other end is mounted so as to be able to slide on rail-shaped support members 20C which extend in the direction of travel F This portion is substantially parallel to the surface of the filter cloth 11 below the vacuum trays 16, and is curved such that the convexity is oriented in the forward direction of travel F of the filter cloth 11 By mounting the vacuum hoses 20B in this manner, they are supported in a state that permits reciprocating along the direction of travel F Sliding members 20D are attached at the portions of the vacuum hoses 20B that are in contact with the support members 20C These sliding members 20D are made of a material that the coefficient of friction to the support members 20C is small and has a superior wear resistance, such as ultrahigh molecular weight polyethylene
Here, the two connection fittings 20 disposed opposite to each other in the transverse direction are disposed so that each of their vacuum pipes 20 A is substantially identically positioned with respect to the direction of travel F In addition, large diameter suction pipes (not illustrated) that extend parallel to the direction of travel F are provided on the both sides of the apparatus body 10m the transverse direction The other ends of the vacuum hoses 20B of the two connection fittings 20 are each connected to the suction pipes Via these suction pipes, the connection fittings 20 are connected to the vacuum apparatus
In the vacuum filtration apparatus described above, by activating the vacuum apparatus, a vacuum force is applied to the mesh body 16D, which serves as the vacuum

chamber, through the vacuum hoses 20B, the vacuum pipes 20A, the reinforcing pipes 17, and the first communicating holes 16E of the plate 16C, and thereby the vacuum force is applied to the slurry S on the filter cloth 11 Due to this vacuum force, the liquid portion of the slurry S on the filter cloth 11 is recovered through the filter cloth 11 in succession through the mesh body 16D, the first communicating holes 16E of the plate 16C, the reinforcing pipes 17, the vacuum pipes 20A, and the vacuum hoses 2 OB In the vacuum chamber (mesh body 16D), the vacuum is released by switching the vent mechanism of the vacuum apparatus to return to atmospheric pressure
The vacuum trays 16 that are adjacent to each other in the direction of travel F are connected together Among these vacuum trays 16, as shown in FIG 1, a drive cylinder 18, such as an air cylinder, is installed on a frame 10A of the apparatus body 10 The drive cylinder 18 expands and contracts along the direction of travel F and is connected to the vacuum tray 16, which is positioned farthest upstream with respect to the direction of travel F Due to the expansion and contraction of the drive cylinder 18, all of the vacuum trays 16 may move reciprocally together at a predetermined stroke in both the forward and reverse direction of travel F, that is, may move reciprocally along this direction of travel F Along with the forward and reverse movement of the vacuum trays 16, the vacuum hoses 20B, whose second ends are connected to the vacuum apparatus, bend by deforming elastically, and the connection fittings 20 move reciprocally as a whole
As shown in FIG 1 and FIG 3, freely rotating support wheels 19 that support the vacuum trays 16 are provided in plurality on the apparatus body 10, and these support wheels 19 are spaced in the transverse direction of the filter cloth 11 The support wheels 19 contact from below a pair of rails 22 that are provided below both ends of the vacuum trays 16 in the transverse direction and extend in the direction of travel F The

vacuum trays 16 may reciprocate on these freely lotating support wheels 19 Contrariwise, the support wheels 19 are caused to rotate by the reciprocation of the vacuum trays 16 by the drive cylinder 18 These support wheels 19, which are all the same shape and same size, are installed so as to be able to rotate freely around a horizontal axis of rotation that extends in the transverse direction via brackets and the like that are provided facing upward on the frame 10A of the apparatus body 10 A support wheel 19 may have a disc shape or a columnar shape with a short axle length, and is centered on this axis of rotation The support wheels 19 are arranged so as to form two parallel rows that extend in the direction of travel F along both edges of the bottom surface of the vacuum trays 16 in the transverse direction The support wheels 19 in each row are disposed at equal intervals in the direction of travel F At the same time, the support wheels 19 in each of the rows align to form pairs in the transverse direction, and the support wheels 19 that form pairs have equal heights in the vertical direction and are disposed at identical positions in the direction of travel F
According to the vacuum filtration apparatus in the present embodiment described above, the connection fittings 20 are provided in plurality, and the vacuum hoses 20B of each of the connection fittings 20 are arranged so that they extend toward opposite sides with respect to the middle part of the vacuum tray 16 in the transverse direction Therefore, each of the vacuum hoses 20B deforms along with the reciprocation of the vacuum tray 16, and even when the restoring forces that would restore the vacuum hoses 20B act on the vacuum tray 16, it is possible to cancel these forces each other at the vacuum tray 16 Therefore, due to the restoring forces of the vacuum hoses 20B, it is possible to restrain to a minimum the forces acting on the vacuum tray 16 in the direction crossing the direction of travel At the same time, it is possible to restrain to a minimum the moment of rotation that causes the vacuum tray 16

to wobble along the surface of the planar part 16A That is, it is possible to restrain the occurrence of the situation in which the travel of the vacuum trays 16 is obstructed, and it is possible to realize the rectilinear stability of the vacuum trays 16
Thereby, as in the present embodiment, even in a structure in which the apparatus body 10 provides both a pair of rails 22 that extend in the direction of travel F under both ends of the vacuum trays 16 in the transverse direction and the support wheels 19 that are arranged on the rails 22 and support the vacuum trays 16 by contacting from below, it is possible to restrain the occurrence of uneven wear, in which the amount of wear of the rails 22 and the support wheels 19 differs on each edge in the transverse direction It is also possible to restrain the tilting of the vacuum trays 16 and it is possible to restrain the occurrence of the situation in which the filter cloth 11 easily moves unevenly and the travel of the vacuum trays 16 is obstructed In addition to this, even in the case in which, for example, guides are provided that restrict the side surface of the vacuum trays 16 in the direction of travel, it is possible to restrain the tilting of the vacuum trays 16 described above Thereby, it is possible to restrain the obstruction of the travel of the vacuum trays 16 due to the situation in which the guide scrapes the side surface of the vacuum trays 16 Furthermore, because the connection fittings 20 are provided in plurality, it is possible to maintain the vacuum force from the vacuum tray 16 on the slurry S even if the diameter of the vacuum hoses 20B of these connection fittings 20 is made small In this case, because the restoring force of the vacuum hoses 20B becomes small, it is possible to further restrain reliably the occurrence of the situation described above, in which the travel of the vacuum tray 16 is obstructed, and at the same time, it becomes possible to implement space saving below the vacuum trays 16 and it becomes possible to implement reductions in the time for maintenance this part

Here, in the present embodiment, because the vacuum hoses 20B are disposed symmetrically with respect to the middle of a vacuum tray 16 in the transverse direction, the restoring force due to each of the vacuum hoses 20B acting on the vacuum tray 16 may be reliably cancel, and it is possible to improve significantly the rectilinear stability of these vacuum trays 16
In addition, because the vacuum hoses 20B are connected from below to the vacuum trays 16 in a bent state so as to form a convexity oriented downstream to the direction of travel F of the filter cloth 11, the vacuum hoses 20B extend in the direction along the surface of the filter cloth 11 and the vacuum trays 16 Therefore, it becomes possible to guarantee the space below the vacuum trays 16 and it becomes possible to restrain an increase in the time for maintenance in this part
Furthermore, because the vacuum hoses 20B are connected to the vacuum trays 16 from the bottom thereof so as to be separated from each other, where the middle part of the vacuum trays 16 in the transverse direction is situated therebetween, the vacuum hoses 20B will never cross each other under the vacuum trays 16 Therefore, it becomes possible to avoid interference between each of the vacuum hoses 20B reliably, and at the same time, it is possible to guarantee an even larger space below the vacuum trays 16
Furthermore, because the plurality of the vacuum trays 16 are configured by being arranged in the direction of travel F of the filter cloth 11 and the vacuum hoses 20B are connected to each of these vacuum trays 16 from below, by making the diameter of the vacuum hoses 20B smaller by providing the connection fittings 20 in plurality, it is possible to restrain the interference between the adjacent vacuum hoses 20B in the direction of travel F, it is possible to implement a reduction in the number of types of parts that form this vacuum filtration apparatus, and it is possible to reduce costs and implement reductions in the operation and maintenance costs

As described above, the present embodiment lllustiates a structure for a vacuum filtration apparatus in which the plurality of the vacuum trays 16 are configured by being arranged in the direction of travel F of the filter cloth 11 and the connection fittings 20 are connected to each of the vacuum trays 16 from below In tins case, the problem may be anticipated in which the space under the vacuum trays 16 is narrowed and thereby interference might occur between the adjacent vacuum hoses 20B in the direction of travel F
However, in the present embodiment, as described above because the diameter of the vacuum hoses 20B may be made smaller by providing the connection fittings 20 in plurality, it is possible to guarantee the space under the vacuum trays 16 and prevent interference between the vacuum hoses 20B, and it is also possible to prevent an increase in the time for maintenance At the same time, it is possible to reduce the number and types of parts that form this vacuum filtration apparatus Thus, it is possible to implement reductions in the cost of this apparatus and reductions in the operation and maintenance costs
In addition, because the reinforcing pipes 17, which are bonded to bottom of the vacuum trays 16 and extend in the transverse direction of the filter cloth 11, are provided with a rib shape, the rigidity of the vacuum trays 16 that withstands deformation due to external forces may be increased Therefore, even in the case in which the restoring forces due to the vacuum hoses 20B act on the planar part 16A of the vacuum trays 16 to deform this planar part 16A, a rigidity that may withstand these restoring forces may be provided to the planar part 16 A Therefore, it is possible to prevent the obstruction of the travel of the vacuum trays 16 reliably, and at the same time, it is possible to restrain the occurrence of uneven movement of the filter cloth 11

Furthermore, the vacuum pipes 20 A aie connected to the bottom surface of the plate 16C of the vacuum tray 16 via the reinforcing pipes 17, which have a higher rigidity than that of this plate 16C that withstands deformation Therefore, even in the case in which the connection part between the vacuum pipes 20A and the vacuum tray 16 is repeatedly subjected to a load due to either the travel of the vacuum trays 16 during the use of this vacuum filtration apparatus or the restoring forces of the vacuum hoses 20B, it is possible to restrain the occurrence of breakage to this connecting part
Specifically, in the case in which a vacuum pipe 20A is directly connected to a plate 16C that has a low rigidity for withstanding the deformation due to external forces, the plate 16C easily deforms due to the restoring forces of the vacuum hoses 20B, and residual stresses due to the repeated reciprocal travel of the vacuum trays 16 accumulate easily Thus, the load acting on the connecting part becomes large and this connecting part becomes comparatively easy to damage
In contrast, as in the case of the present embodiment, when the vacuum pipes 20 A are connected to the reinforcing pipes 17, whose rigidity for withstanding the deformation due to an external force is comparatively high, the restoring forces of the vacuum hoses 20B act on the reinforcing pipes 17, and do not directly act on the vacuum trays 16 Because the reinforcing pipe 17 itself is very rigid, the deformation due to the restoring forces and the accumulation of the residual stresses may be restrained Therefore, the occurrence of damage to the connecting part between the vacuum pipes 20A and the bottom surface of the plate 16C may be restrained, and thereby it is also possible to realize both an increase in the service life of the vacuum filtration apparatus and a reduction in the time for maintenance the vacuum filtration apparatus
In the case of a large-scale vacuum filtration apparatus having the filter cloth 11 whose width is equal to or greater than 2500 mm, the amount of the filtrate recovered

from the slurry S is increased of course, and it is required that the vacuum force applied to the slurry S be uniform for a short period of time in the transverse direction of the vacuum trays 16 In order to attain this, it is possible to consider using a structure in which the vacuum pipes 20A are provided in plurality so as to be spaced in the transverse direction on the bottom surface of the plate 16C that forms the vacuum tray 16, connecting pipes that connect these vacuum pipes 20A together are disposed, and one vacuum hose 20B is connected to this connecting pipe However, in this type of structure, due to the restoring forces of the vacuum hoses 20B, forces will act similarly on the connecting pipe as well, and the restoring forces act on the bottom surface of the plate 16C from each of the of vacuum pipes 20 A that are connected in plurality to this connecting pipe Thus, there is the concern that further deformation to the plate 16C may occur easily and that this will contribute both to the obstruction of the travel of the vacuum trays 16 and the shortening of the service life of the vacuum filtration apparatus However, in the present embodiment, the reinforcing pipes 17 that have a higher rigidity for withstanding the deformation than that of the plate 16C are provided on the bottom surface of this plate 16C The second communicating holes 17A are bored in plurality in the upper surface of these reinforcing pipes 17 so as to be spaced in the transverse direction of the vacuum trays 16 Also, the third communicating holes 17B that communicate with the vacuum pipe 20 A are bored in the bottom surfaces of the reinforcing pipes 17, and these third communicating holes 17B communicate with the vacuum apparatus Therefore, among the vacuum trays 16, when locations at which a vacuum force is applied to the vacuum chamber (mesh body 16D) of the vacuum trays 16 are provided in plurality, it is possible to limit the locations at which the restoring forces of the vacuum hoses 20B are directly acting to the reinforcing pipes 17 which have a comparatively high rigidity Furthermore, in a structure that uses the connecting pipes,

for one connection fitting 20, the part that connects the plate 16C must be provided at two or more locations However, in the present embodiment, it is possible to limit this type of connecting part to one location for one connection fitting 20 Specifically, in the present embodiment, the interior spaces 17C of the reinforcing pipes 17 for reinforcing the vacuum trays 16 apply a vacuum force to these vacuum trays 16 and at the same time double as flow paths for recovering the filtrate In addition, even if an unevenness in the strength of the vacuum force occurs between the plurality of the vacuum pipes 20A and the vacuum hoses 20B, due to the presence of these reinforcing pipes 17 (interior spaces 17C), it is possible to apply a vacuum force uniformly to the vacuum chamber from the plurality of the second communicating holes 17A Therefore, in the large-scale vacuum filtration apparatus, it becomes possible to produce the vacuum force evenly for a short period of time in the transverse direction of the vacuum trays 16 That is, in this type of structure as well, it is possible to restrain the occurrence of deformation in the plate 16C reliably, and it is possible to restrain reliably both the obstruction of the travel of the vacuum trays 16 and the reduction in the service life of the vacuum filtration apparatus
While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting Additions, omissions, substitutions, and other modifications may be made without departing from the spirit or scope of the present invention Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims
For example, the direction of the convexity of the curved shape of the vacuum hoses 20B may be downstream to the direction of travel F In addition, the vacuum hoses 20B should be disposed so as to extend to opposite sides with respect to the middle part in the transverse direction of the vacuum tray 16 at least For example, the vacuum hoses

20B are not limited to being connected to the bottom of the vacuum tray 16, and they may be connected to the side thereof In the structure in which the vacuum hoses 20B are connected to the bottom of the vacuum tray 16, the vacuum hoses 20B may be disposed such that the vacuum hoses 20B cross each other along the extension from the connection with the vacuum tray 16
In addition, the number of the vacuum hoses 20B connected to one vacuum tray 16, the connection positions and the like are not limited by the embodiments As long as the restonng forces acting on the vacuum trays 16 due to each of the vacuum hoses 20B that accompanies the reciprocation of the vacuum tray 16 are cancel, the material of the vacuum hose 20B, external diameter of the vacuum hose 20B, the positions of the connection between the vacuum hoses 20B and the vacuum tray 16, and the like may be altered by appropriate selection
The structure is not hmited to which the vacuum tray 16 provides the reinforcing pipes 17, the vacuum pipes 20 A may be directly connected to the bottom surface of the plate 16C without interposing the reinforcing pipes 17 therebetween The entire vacuum hoses 20B that are connected to the plurality of vacuum trays 16 may be connected to one vacuum apparatus Alternatively, the vacuum hoses 20B connected to each or the plurality of the vacuum trays 16 may be connected to different vacuum apparatuses respectively

We claim:
1. A vacuum filtration apparatus for filtering slurry (S) by a vacuum, Comprising:
an apparatus body (10);
a filter cloth (11) to be supplied with the slurry (s), that travels substantially horizontally with respect to the apparatus body (10);
a vacuum tray (16) disposed under the filter cloth (11) and reciprocated in direction of travel (F) of the filter cloth (11);
vacuum hoses (20B) having elasticity, ends of at least two of the vacuum hoses (20B) being connected to the vacuum try (16) so as the transversely extend in opposite directions with respect to the middle of the vacuum tray (16), and the other ends thereof being connected to a vacuum apparatus which applies a vacuum to the slurry (S) through the filter cloth (11) and the vacuum tray (16).
2. A vacuum filtration apparatus as claimed in claim 1, wherein the vacuum hoses (20 B) are disposed symmetrically with respect to the middle of the vacuum tray (16) in the transverse direction.
3. A vacuum filtration apparatus as claimed in claim 1, wherein the vacuum hoses (20B) connect to the vacuum tray (16) from below in a bent state so as the form a convexity in the upstream or downstream direction of travel (F) of the filter cloth (11).
4. A vacuum filtration apparatus as claimed in claim 1, wherein the vacuum hoses (20B)
are connected to the vacuum tray (16) from below, and are separated from each other,
where the middle part of the filter cloth (11) in the transverse direction is situated
therebetween.
5. A vacuum filtration apparatus as claimed in claim 1, wherein a plurality of the vacuum trays (16) are arranged in the direction of travel (F) of the filter cloth (11), and the vacuum hoses (20B) are connected from below to each of the vacuum trays (16).

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=ww7pGbMkJ8OJY+D37wzwuA==&loc=+mN2fYxnTC4l0fUd8W4CAA==

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Patent Number

270675

Indian Patent Application Number

338/DEL/2005

PG Journal Number

02/2016

Publication Date

08-Jan-2016

Grant Date

08-Jan-2016

Date of Filing

17-Feb-2005

Name of Patentee

TSUKISHIMA KIKAI CO.,LTD

Applicant Address

17-15, TSUKUDA 2-CHOME, CHUO-KU, TOKYO, JAPAN

Inventors:

#	Inventor's Name	Inventor's Address
1	IWASAKI, SHUJI	C/O TSUKISHIMA KIKAI CO.,LTD., 17-15, TSUKUDA 2-CHOME, CHUO-KU, TOKYO, JAPAN
2	KOJIMA, HISASHI	C/O TSUKISHIMA KIKAI CO.,LTD., 17-15, TSUKUDA 2-CHOME, CHUO-KU, TOKYO, JAPAN

PCT International Classification Number

B01D 33/44

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2004-089346	2004-03-25	Japan