JP3537801B2 - Vacuum filtration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum filtration apparatus for filtering a slurry supplied on a filter cloth which can travel substantially horizontally by vacuum suction using a vacuum tray provided below the filter cloth. It is about.

[0002]

2. Description of the Related Art Japanese Patent No. 2,707,170 and Japanese Patent No. 3091200, for example, disclose an endless form of a filter cloth by winding a plurality of rolls provided on an apparatus body. A plurality of vacuum trays can be directed in the traveling direction of the filter cloth under the filter cloth in the filter section in which the filter cloth on the upper part of the apparatus can be moved horizontally in the circumferential direction. Those provided side by side are described. Here, these vacuum trays are box-shaped horizontally flat, and a large number of suction holes are formed in the upper surface thereof, and the inside of the box below the upper surface is a vacuum suction device. Is connected to a vacuum suction chamber. Thus, in such a vacuum filtration device, the slurry is supplied on the filter cloth adhered to the upper surface of the vacuum tray in the filtration section on the rear side of the filtration section in the traveling direction of the filter cloth, The vacuum suction force generated in the vacuum suction chamber by the vacuum suction device while the filter cloth is stopped while moving the slurry together with the filter cloth on the vacuum tray in the above-described traveling direction by the intermittent running of the filter cloth. Is applied to the slurry from the suction hole on the upper portion of the vacuum tray via the filter cloth, whereby the liquid component of the slurry is suctioned to perform filtration.

[0003]

In such a vacuum filtration apparatus, the vacuum suction chamber of the vacuum tray and the vacuum suction device are connected via a suction pipe. A vacuum shutoff valve is provided on the suction device side, and a vacuum release pipe having a vacuum release valve is provided between the vacuum shutoff valve and the vacuum suction chamber of the vacuum tray. When filtering the slurry, the vacuum release valve is closed and the vacuum shut-off valve is opened to generate a vacuum suction force by a vacuum suction device in the vacuum suction chamber of the vacuum tray. By applying this vacuum suction force to the slurry through the filter cloth from
While the filtrate is suctioned to dehydrate and filter the slurry, when the filter cloth is run intermittently with the slurry, the vacuum shutoff valve is closed and the vacuum release valve is opened to draw air from the vacuum release pipe into the suction pipe, The vacuum suction chamber is once returned to the atmospheric pressure to prevent the filter cloth from being retained on the vacuum tray before the filter cloth is run.

However, the time from the completion of the dehydration filtration of the slurry to the time when the filter cloth is intermittently run and the next dehydration filtration is performed is the same as the time during which the vacuum suction of the filtrate by the vacuum tray is not performed. Therefore, it is desirable to shorten this time as much as possible in order to improve the working efficiency by the vacuum filtration device. For this reason, when the vacuum suction chamber is returned to the atmospheric pressure, the opening and closing of the vacuum shutoff valve and the vacuum release valve are performed. Switching must also be performed such that the opening valve is opened at a time while the shut-off valve is closed. However, if the vacuum release valve is opened at a stretch in this manner, the air drawn from the vacuum release tube also flows into the vacuum suction chamber at a stretch via the suction tube. Is generated and the surrounding environment is spoiled. However, in order to suppress the generation of noise due to such air suction noise, it is necessary to increase the diameter of the vacuum release pipe and the diameter of the vacuum release valve. Increasing the size inevitably leads to an increase in the size and cost of the vacuum filtration device, and furthermore, when the filtrate obtained by filtering the slurry is used as a product, a vacuum opening tube having a larger tube diameter is used. A large amount of dust and dust in the surrounding atmosphere is sucked into the suction pipe together with the air from the opening, and there is a possibility that the filtrate is contaminated.

The present invention has been made under such a background, and even if the vacuum release valve is opened at a stretch to improve the working efficiency as described above, no loud noise is generated, and furthermore, there is no noise in the atmosphere. It is an object of the present invention to provide a vacuum filtration device in which a filtrate is not contaminated by dust or dirt.

[0006]

In order to solve the above problems and achieve the above object, the present invention provides a vacuum suction device provided under a filter cloth which is provided so as to be able to travel substantially horizontally on an apparatus body. A vacuum tray connected to the device, a vacuum filtration device for filtering the slurry supplied on the filter cloth by vacuum suction through the filter cloth by the vacuum tray, wherein the vacuum tray and the vacuum The suction device is connected to the suction device via a suction tube, and the suction tube is connected to a vacuum release tube having a vacuum release valve. At the opposite end to between the vacuum release valve, the air filter is provided, diether
A filter is the above vacuum release tube with the opening facing downward.
Cylindrical cover attached to the opposite end of the
ー, a sheet in which fibers are woven is folded in a bellows shape
And a filter element wound cylindrically.
The filter element is placed between the inner circumference of the cover and
The lower end of the cover is disposed in the cover and spaced apart therefrom.
The outer peripheral side is characterized by being opened in a ring shape . Therefore, according to such a vacuum filtration device, dust and dirt in the air are removed by the air filter from the air flowing into the vacuum release pipe when the vacuum release valve is opened, so that contamination of the filtrate is naturally prevented. The speed at which the inflowing air passes through the air filter is suppressed by the resistance of the inflowing air, thereby preventing generation of noise.

Here, it is desirable that such an air filter is provided with a filter element obtained by bending a sheet woven of fibers such as polyester into a bellows shape, whereby the volume of the air filter itself is reduced. Since a large surface area of the filter element can be ensured, dust and dirt can be reliably collected and removed from the inflowing air, and a greater resistance is given to the air to reduce the inflow speed. Noise can be prevented. On the other hand, when the suction tube is branched into a plurality of branches, such as when the vacuum suction chambers of a plurality of vacuum trays are connected to one vacuum suction device, the vacuum opening tube should avoid the branch portion of the suction tube. It is desirable to connect the vacuum opening pipe to the suction pipe branched into a plurality of branches without performing complicated processing.

[0008]

FIG. 1 to FIG. 7 show an embodiment of the present invention. In the vacuum filtration device of the present embodiment, an endless belt-shaped filter cloth 11 is provided in the device body 10.
Are sequentially wound around a plurality of rolls 12. The upper portion of the filter cloth 11 is disposed so as to extend in the horizontal direction to form a filter section 11 </ b> A. And this filter cloth 11
Is a filter cloth driving device 13 provided at a lower portion of the device main body 10.
Thus, the roll 1 is moved so that the filtration unit 11A travels from one end side (left side in FIG. 1) to the other end side (right side in FIG. 1) in the traveling direction indicated by the arrow F in the figure.
1 are intermittently driven in a clockwise direction in FIG. 1, a vacuum tray 14 is provided below the filtering section 11A of the filter cloth 11, and a device is provided above the filtering section 11A. A supply device 15 for slurry S is provided on the one end side of the main body 10. The slurry S supplied from the supply device 15 onto the filter cloth 11 on the vacuum tray 14 is
While being moved in the traveling direction F along with the traveling of the filtration unit 11A, the vacuum suction is performed through the filter cloth 11 by the vacuum tray 14 to be filtered, and the dehydrated cake is discharged from the other end of the traveling direction F side. Has been done.

As shown in FIG. 1, the filter cloth driving device 13 has an arm 13A rotatable around a swing axis parallel to the rotation axis of the rolls 12. Is provided so as to be able to swing at a predetermined angle about the swing axis by a driving means 13B such as a cylinder device attached to the device main body 10. This arm 13A is also provided with a cylinder device or the like. Is provided, and the clamper 13C
The filter cloth 11 is circulated at a predetermined stroke by causing the arm 13A to swing in one direction by the driving means 13B while holding the filter cloth 11 therebetween, whereby the filter section 11A is caused to travel in the traveling direction F, and The arm 13A is swung in the direction opposite to the one direction with the clamper 13C separating the filter cloth 11, so that the arm 13A returns to the original position without pulling back the filter cloth 11, By repeating such operations, the filter cloth 11 is intermittently driven to rotate, and the filter section 11A is also driven to intermittently run. An adjusting roll 16 wound around the filter cloth 11 is provided below the one end of the apparatus main body 10.
A tension adjusting device 16 for the filter cloth 11 comprising an arm 16C which is provided with A and is also swingable by a driving means 16B such as a cylinder device.

In the vicinity of the roll 12 located on the traveling direction F side (the other end side) of the filtration unit 11A, the slurry S supplied on the filtration unit 11A and filtered by the vacuum tray 14 is disposed. A knife 10A for scraping off the dewatered cake from the filter cloth 11 and peeling off is provided on the apparatus main body 10, and the dewatered cake peeled off by the knife 10A is provided under the paddle provided on the most other end side of the apparatus main body 10 below. It is stored in the mold conveyor 10B and discharged. Further, on the other end side of the lower part of the apparatus main body 10, the dewatered cake was peeled between the roll 12 on the traveling direction F side of the filtration unit 11A and the filter cloth driving device 13 in the circulation path of the filter cloth 1. A filter cloth cleaning device 17 for cleaning the later filter cloth 11 is provided. Here, the filter cloth cleaning device 17 is connected to a cleaning water supply device (not shown) in a cleaning box 17A provided at a lower portion of the device main body 10 so that the filter cloth 11 can pass therethrough. Is provided so as to be able to advance and retreat in the direction in which the filter cloth 11 passes through the inside of the washing box 17A. In the present embodiment, particularly, the washing pipe 17B is provided with the filter cloth driving device 13. The driving means 13B allows the arm 13A to swing forward and backward integrally with the swing of the arm 13A.
By adjusting the speed at which A returns to the original position, the filter cloth 11 can be reliably washed.

On the other hand, in the present embodiment, the vacuum tray 14 is constituted by a plurality (eight in the present embodiment) of vacuum trays 14A to 14H arranged in the running direction F. These vacuum trays 14 </ b> A to 14 </ b> H have lengths substantially equal to each other in the running direction F, equal to the intermittent travel stroke of the filter cloth 11, and
1 are substantially the same shape and the same size in the width direction (vertical direction in FIG. 2; horizontal direction in FIGS. 3 to 5). Mounted and fixed as possible. Each of the vacuum trays 14 is in the form of a flat box in the horizontal direction which is flattened up and down, and its upper surface 18 has a wide flat portion 18A whose center in the width direction of the filter cloth 11 is horizontal. At the same time, on both sides in the width direction, wall portions 18 which are inclined upward toward the outside in the width direction are provided.
B, 18B are formed with a smaller width than the flat portion 18A, and these flat portions 1A are located between the vacuum trays 14A to 14H.
8A and the wall portions 18B, 18B are arranged so as to be flush with each other in the running direction F.
The center of the width direction is superimposed on the flat portion 18A, and both sides are brought into close contact with the upper surface portion 18 so as to ride on the wall portions 18B, 18B, and run in the running direction F. Therefore, the slurry S supplied on the filter cloth 11 also has these walls 18B, 18B on both sides of the vacuum tray 14 via the filter cloth 11.
The cross-section perpendicular to the running direction F, which is deposited on the upper surface, presents an isosceles trapezoid shape that is flat and flat in the width direction.

Further, the inside of the box shape formed by the vacuum tray 14 is an air-tight and liquid-tight vacuum suction chamber 19, which is connected to a vacuum suction device such as a vacuum pump (not shown). Each vacuum tray 14A-14H
Are isolated from each other. The upper surface 18 is provided with a large number of suction holes communicating with the vacuum suction chamber 19, and the slurry S on the filter cloth 11 is adhered to the upper surface 18 through the filter cloth 11 in close contact with the upper surface 18. Vacuum suction chamber 1
9, the slurry S can be vacuum-suctioned as described above. In this embodiment, the slurry S is located on the side of the vacuum trays 14A to 14H in the traveling direction F of the filter cloth 11. Vacuum trays 14F to 14H
The slurry S can be vacuum-suctioned from the wall portion 18B of the upper surface portion 18 through the filter cloth 11.

That is, in the present embodiment, the vacuum suction chamber 19 of each vacuum tray 14 extends so as to extend from below the flat portion 18A at the center of the upper surface portion 18 to below the wall portions 18B, 18B on both sides. But with a flat part 1
The portion below 8A and the portion below both walls 18B, 18B are separated by, for example, a partition indicated by reference numeral 19C in FIG. The plurality of vacuum trays 14A to 14A
H, the traveling direction F of the filter cloth 11 in the filtration unit 11A
Of the plurality of vacuum trays 14A to 14E on the rear side (one end side) of the vacuum tray 14A (in this embodiment, the majority is five), only the vacuum suction chamber 19 below the flat portion 18A of the upper surface portion 18 is subjected to the vacuum suction. Therefore, only the lower portion of the flat portion 18A functions as a vacuum suction chamber 19, and the slurry S is evacuated from the suction hole formed in the flat portion 18A through the filter cloth 11 to the slurry S. While the suction force is applied, the remaining plural (three in this embodiment, less than three) vacuum trays 1 in the remaining part on the running direction F side (the other end side)
4F to 14H, the portion below the flat portion 18A and the wall portion 18
B, the lower part of 18B are connected to the vacuum suction device,
As shown in FIGS. 5 and 6, these portions function as a vacuum suction chamber 19A and vacuum suction chambers 19B and 19B, respectively. Further, as shown by a line P in FIG. The slurry S is also drilled from the flat portion 18A to the wall portion 18B, and a vacuum suction force is applied to the slurry S from the suction hole drilled in the wall portion 18B through the filter cloth 11 so that the slurry S is vacuum-suctioned. It is possible. Moreover, in the present embodiment, these vacuum suction chambers 19A and the vacuum suction chambers 19B, 19B are connected to different vacuum suction devices, and thereby act on the slurry S from the wall portion 18B via the filter cloth 11. The vacuum suction force and the vacuum suction force acting from the flat portion 18A on the upper surface portion 18 on the inner side in the width direction of the wall portion 18 can be controlled to different strengths. 14F-14
In H, the vacuum suction force acting on the slurry S from the wall portion 18B is stronger than the vacuum suction force acting on the flat portion 18A.

On the other hand, the vacuum suction chamber 19 of the vacuum tray 14
(19A, 19B) and the above-mentioned vacuum suction device are connected by suction pipes 20A to 20D arranged to extend horizontally below the vacuum trays 14A to 14H from the side of the device main body 10. However, the vacuum suction chambers 1 of the two vacuum trays 14A and 14B on the rear side in the running direction F
9 and 19 are connected by a common suction pipe 20A, and the vacuum suction chambers 19 and 19 of the next two vacuum trays 14C and 14D on the running direction F side are connected by a common suction pipe 20B. Further, in the four vacuum trays 14E to 14H on the traveling direction F side, the vacuum suction chamber 19 of the vacuum tray 14E and the vacuum suction chamber 19A of the vacuum trays 14F to 14H are also connected by a common suction pipe 20C, while Vacuum suction chamber 19 of trays 14F to 14H
B and 19B are also connected by a common suction tube 20D, and the apparatus main body 10 is provided with a plurality (four) of vacuum suction devices, and these suction tubes 20A to 20D are connected to different vacuum suction devices. Have been. Accordingly, in this embodiment, a part of the vacuum suction chambers 19 (19A, 19B) of the plurality of vacuum trays 14A to 14H arranged in the running direction F of the filter cloth 11 has a different vacuum suction from the others. The device is connected to the vacuum tray 14
E to 14H of the vacuum suction chamber 19A and the vacuum suction chamber 19
B and 19B are also connected to different vacuum suction devices as described above.

Further, the suction pipe 2 connected to the vacuum suction chambers 19, 19A located below the upper surface portion 18A.
0A to 20C are branched into two in the suction pipes 20A and 20B and four in the suction pipe 20C according to the number of the vacuum trays 14 to be suctioned, and are respectively provided in the center portions of the vacuum trays 14A to 14H in the running direction F. After extending in the width direction, three portions, a central portion of the flat portion 8A in the width direction and portions equidistantly provided on both outer sides thereof,
In the traveling direction F as well, the vacuum tray 14 branches into three places: a center of the plane portion 8A of each vacuum tray 14 and places equidistantly disposed on the traveling direction F side and the traveling direction F rear side. 14H, a vacuum suction chamber 19,
19A and therefore each vacuum tray 14
The vacuum suction chambers 19 and 19A of these two
Are connected to the suction pipes 20A to 20C at a plurality of locations (a total of nine locations of three locations in this embodiment) at equal intervals. On the other hand, the suction pipe 20D connected to the vacuum suction chamber 19B of the vacuum trays 14F to 14H is also in the traveling direction F.
In the vacuum tray 14 from between the suction pipes 20B and 20D.
After being extended to the center part in the width direction, it is branched to both outer sides in the width direction, is extended below the vacuum suction chambers 19B, 19B, and is further bent in the running direction F. The vacuum suction chambers 19 extend parallel to each other in the running direction F and are located on both sides of each of the vacuum trays 14F to 14H.
B and 19B are also connected vertically from below, and this suction tube 20D is equally spaced from the vacuum suction chambers 19B and 19B of the vacuum trays 14F to 14H in the running direction F, respectively. Connected at multiple locations.

Each of the suction pipes 20A to 20D is provided with a vacuum shut-off valve 21 such as a butterfly valve at a connection portion with the vacuum suction device side, and also on the vacuum tray 14 side with respect to the vacuum shut-off valve 21. A vacuum release pipe 23 having a vacuum release valve 22 such as a butterfly valve is provided so as to extend vertically upward, and an air filter 24 is attached to an upper end of the vacuum release pipe 23. Here, as shown in FIG. 1, the vacuum release pipe 23 is one of the vacuum trays 14A and 14A among the suction pipes 20A to 20D branched into a plurality of branches.
In the suction pipes 20A and 20B that branch into two toward the vacuum trays 4B and 14C and 14D, these are provided at the branch portions that branch into two, while they branch into four toward the vacuum trays 14E to 14H. The above suction tube 20
In C, the shoulder between the branching portions of the vacuum trays 14E and 14F, that is, the suction tube 20C is provided at a portion extending in a straight tube shape so as to avoid a portion where the suction tube 20C branches. In the suction tube 20D,
Vacuum suction chambers 18B, 18 of vacuum trays 14A to 14H
A suction tube 20D before branching to B is provided in one portion. The vacuum release pipe 23 provided in each of the suction pipes 20A to 20D has a height at the position where the vacuum release valve 22 is provided, and the liquid of the slurry S supplied on the filter cloth 11 of the vacuum tray 14 is provided. It is designed to be higher than the height of the surface.

Further, the air filter 24 is provided with the air filter 24 shown in FIG.
As shown in the figure, a sheet in which fibers of polyester or the like are knitted in a bellows shape in a bottomed cylindrical cover 24B which is detachably attached to the upper end portion of the vacuum release tube 23 with the opening downward with a thumbscrew 24A. The filter element 24C obtained by winding the folded filter into a cylindrical shape is covered with the cover 24.
The filter element 24C is arranged so as to be spaced apart from the inner periphery of B and to be located on the outer periphery side with respect to the opening of the vacuum release tube 23. The bottom plate 24D is closed by an annular bottom plate 24D disposed on the outer periphery of the opening of the vacuum release tube 23, and a circular opening is formed between the outer periphery of the bottom plate 24D and the lower end of the cover 24B. Thus, in the present embodiment, the filter cloth 11 after vacuum suction in each vacuum tray 14 is used.
When the vehicle travels, by closing the vacuum shut-off valve 21 and then opening the vacuum release valve 22, the filter element 2 is sucked from the outer peripheral side of the lower end of the cover 24B.
The air that has passed through the bellows-shaped peripheral wall portion of 4C is
3 and the vacuum suction chamber 19 through the suction pipes 20A to 20D.
(19A, 19B), and the pressure in the vacuum suction chamber 19 is returned to the atmospheric pressure.

In this embodiment, the filtering unit 11A
The supply device 15 of the slurry S provided on the one end side of the apparatus above can be advanced and retracted in the traveling direction F by a driving means 25 such as an air cylinder provided in the apparatus main body 10. Here, the supply device 15 is configured to be able to advance and retreat within a range where the vacuum tray 14A is provided in the traveling direction F, on the vacuum tray 14A at one end of the vacuum tray 14 which is the most rearward in the traveling direction F. I have. On the other hand, three vacuum trays 14C to 14E located on the traveling direction F side from one vacuum tray 14A are
Washing devices 26A to 26C are provided to supply the washing liquid L to the cake on which the slurry S located on the vacuum trays 14C to 14E is suction-filtered to wash the cake, and these washing devices 26A to 26C are also provided. The vacuum trays 16 </ b> C to 16 </ b> E can move forward and backward in the traveling direction F in a range where the vacuum trays 16 </ b> C to 16 </ b> E are provided. Further, in the present embodiment, the cleaning devices 26A to 26C are provided with a driving unit 2 such as another air cylinder different from the driving unit 25 of the supply unit 15.
7, so that the supply device 25 and the cleaning devices 26A to 26C can advance and retreat in the traveling direction F independently of each other.

Further, the cylinder device such as the air cylinder constituting the driving means 25 of the supply device 15 is attached to the device main body 10 so that the cylinder rod is protruded and retracted in the traveling direction F of the filter cloth 11. The supply device 15 is attached to the distal end of the cylinder rod so that it can move forward and backward. In contrast, the cleaning device 2
The cylinder device constituting the driving means 27 of 6A to 26C is provided so that the cylinder rod is protruded and retracted on the rear side in the running direction F opposite to the driving means 25, and the cleaning devices 26A to 26C are In the embodiment, they are connected to each other, and can be integrally moved forward and backward by this one drive means 27. The heights of the supply ports of the cleaning liquid L of the two cleaning devices 26B and 26C on the traveling direction F side are equal to each other, and are lower than the position of the supply port of the cleaning device 26A on the rear side of the traveling direction F. I have.

However, in the vacuum filtration device thus configured, the vacuum suction chambers 19, 19A,
Suction pipes 20A-20 for connecting 19B and a vacuum suction device
D, a vacuum release pipe 2 provided with a vacuum release valve 22 for releasing the interior of the vacuum suction chambers 19, 19A and 19B to atmospheric pressure.
3, the suction tube 20A of the vacuum opening tube 23
20D, an air filter 24 is provided at the end opposite to the vacuum release valve 22 with the vacuum release valve 22 interposed therebetween, so that when the vacuum release valve 22 is first opened, the vacuum release valve is opened. Dust and dust in the air flowing into the pipe 23 can be collected and removed by the air filter 24, and the dust and dust enter the vacuum suction chambers 19, 19A and 19B and are filtered from the slurry S. It is possible to prevent the filtrate from being contaminated. Therefore, even when this filtrate is used as a product, the filtrate can be kept clean, and the quality of the product can be maintained without a step of removing impurities such as dust or dust. Improvement can be achieved.

Further, as described above, the vacuum release tube 23
By providing an air filter 24 at the end of the vacuum filter, the inflow speed of the air flowing into the vacuum opening pipe 23 when the vacuum opening valve 22 is opened is increased in the vacuum filtration device having the above configuration. Since the energy is reduced by the resistance at the time of passage, the energy radiated at the time of the air inflow is also reduced based on the inflow velocity, so that the noise generated by the divergence of the energy is also suppressed. For this reason, without increasing the diameter of the vacuum release pipe 23 or the diameter of the vacuum release valve 22, the vacuum release valve can be increased without increasing the size and cost of the vacuum filtration device. Even if the 22 is opened all at once, it is possible to prevent the generation of loud noises as in the past, and to prevent the surrounding environment from being disturbed by such loud noises while shortening the time of vacuum release. Work efficiency can be reliably improved. Although the vacuum tray 14 is fixed to the apparatus main body 10 and the filter cloth 11 is intermittently moved in the present embodiment, the filter is described as an example. Of course, it is also possible to apply the present invention to a vacuum filtration device in which the vacuum tray can move forward and backward with a constant stroke in the traveling direction.

In the present embodiment, the filter element 24C of the air filter 24 is formed by a sheet in which fibers of polyester or the like are woven as described above, and air passes between the fibers forming the sheet. In this case, dust and dirt are collected and the resistance is reduced, so that the inflow speed is reduced. The filter element 24C is formed by bending such a sheet in a bellows-like manner, thereby increasing the surface area of the filter element 24C without excessively increasing the volume of the air filter 24 itself. As a result, it is possible to more effectively prevent the apparatus main body 10 of the vacuum filtration apparatus from being enlarged, and to promote efficient and reliable prevention of filtrate contamination and suppression of noise. In addition, in the air filter 24 of the present embodiment, the filter element 24C is formed by further winding the sheet folded in a bellows shape into a cylindrical shape. 24B detachably attached to the end of the cover 23
As a result, dust and dirt are covered with the filter element 24C.
Can be reliably prevented from being sucked without being trapped in the filter element, and the trapping ability of the slurry S splashed during supply or the like to the filter element 24C is prevented. In addition, there is an advantage that inspection and replacement of the filter element 24C are easy.

Further, in the present embodiment, such an air filter 24 is provided at the end of the vacuum release pipe 23.
Are suction pipes 20A, 2B which are branched into two from the vacuum suction device and connected to the vacuum trays 14A to 14D, respectively.
0B, the suction pipe 20C is disposed so as to be located at the branch portion, whereas the suction pipe 20C which is branched into four larger portions and connected to the vacuum trays 14E to 14H has the branch portion. The suction tube 20C is disposed in a portion extending in a straight tubular shape, avoiding the above. However, this point,
In the case of the suction tubes 20A and 20B in which the number of vacuum trays 14 to be connected is small and thus the portions which are formed into straight tubes are also short, the above-described branch portions and the elbow portions where the suction tubes 20A and 20B are bent in an L shape are used. Although the open pipe 23 must be provided, when a relatively long straight tubular portion is formed with a large number of vacuum trays 14 to be connected like the suction pipe 20C, the branch section is avoided. By providing the vacuum opening tube 23 in the straight tubular portion, it is not necessary to perform complicated processing for connecting the vacuum opening tube 23 to the branch portion having an originally complicated shape, and as a result, the suction tube 20C
And the cost of the vacuum filtration device can be further reduced.

On the other hand, in the vacuum filtration device of the present embodiment, as described above, the vacuum suction chamber 19 of the vacuum tray 14 is
In the vacuum trays 14F to 14H on the traveling direction F side,
The wall portions 1 on both sides from below the flat portion 18A at the center of the upper surface portion 18
8B and 18B, and a suction hole is also formed in the walls 18B and 18B, so that a vacuum suction force can be applied to the slurry S also from the walls 18B. Accordingly, the slurry S deposited on the wall portion 18B, which would be difficult only by vacuum suction from the flat portion 18A, can be surely subjected to dehydration filtration, and thus the vacuum suction chambers 19 and 19A are provided as described above. , 19B and the vacuum suction device are connected at a plurality of locations, and the dewatered cake of the slurry S that has been dewatered and filtered locally has a high liquid content, and a portion having a non-uniform liquid content is removed. This can be prevented more reliably, and the liquid content can be further reduced even in the whole cake. Such a non-uniform liquid content of the cake and insufficient dewatering filtration allow a smooth process in the next step. By preventing the processing from being hindered, the efficiency of the processing in the next step can be improved.
Moreover, in the present embodiment, after the vacuum trays 14C to 14E provided with the washing devices 26A to 26C in the traveling direction F of the filter cloth 11, the vacuum trays 14F to 14H for final dehydration filtration of the slurry S are provided. In this manner, the slurry S can be vacuum-suctioned from the wall 18B, that is, the vacuum suction can be performed only from the necessary portion from the wall 18B. The dehydration filtration of the slurry S on the wall portion 18B can be efficiently performed as described above without increasing the force. However, if necessary, the vacuum trays 14 </ b> A to 14 </ b> E may be vacuum-sucked from the wall 18 </ b> B rearward in the traveling direction F.

In the present embodiment, in particular, in the vacuum trays 14F to 14H on the traveling direction F side where the final filtration of the slurry S is performed, the vacuum trays 14F to 14H are formed below the flat portion 18A at the center of the upper surface portion 18. Vacuum suction chamber 19A and wall 18
Vacuum suction chambers 19B, 19B formed below B, 18B
Are separated by a partition wall 19C, and are connected to different vacuum suction devices via different suction pipes 20C, 20D. The vacuum suction devices allow slurry from the vacuum suction chambers 19A, 19B to pass through the filter cloth 11 via the filter cloth 11. The vacuum suction force acting on S can be controlled to different strengths. And among these, the vacuum suction chamber 19 on the wall portion 18B side
The vacuum suction force acting on the slurry S from B causes the flat portion 18
Since the vacuum suction force acting on the slurry S from the vacuum suction chamber 19A on the A side is made stronger, according to the present embodiment, as described above, this wall 1 is difficult to efficiently dehydrate and filter.
The slurry S deposited on the surface of the plurality of vacuum trays 14 can be reliably filtered, and the dewatering efficiency can be further improved and the liquid content can be made uniform.
Of these, the vacuum suction force is controlled to a different strength at the stage where the dewatered cake is finally formed on the traveling direction F side of the filter cloth 11, so that the processing in the next step can be more reliably performed smoothly.
It can promote efficiency.

In this embodiment, the wall 18
Although the vacuum suction force acting from the vacuum suction chamber 19B on the B side is made stronger than the vacuum suction force by the vacuum suction chamber 19A on the flat portion 18A side, the thickness of the slurry S becomes thin depending on the properties of the slurry S. When a high vacuum suction force is applied to the wall 18B, the dewatered cake may be cracked and the vacuum suction may be short-passed. In such a case, the vacuum suction force from the vacuum suction chambers 19A and 19B is used. Or the flat portion 18
The vacuum suction force from the vacuum suction chamber 19A on the A side is applied to the wall 18B.
May be made stronger than the vacuum suction force from the side vacuum suction chamber 19B. In this embodiment, in particular, when isolating the vacuum suction chambers 19A and 19B, one vacuum suction chamber 19 is extended below the wall portions 18B and 18B, and a partition wall 19C is provided. It has an advantage that the vacuum suction chambers 19A and 19B can be easily formed.
Independent vacuum suction chambers 19A and 19B may be formed below 8B and 18B, respectively.

In this embodiment, the vacuum tray 1
4, a supply device 15 for supplying the slurry S to the filter cloth 11 on the vacuum tray 14A on the rear side in the traveling direction F, and the filter cloth 11 on the vacuum trays 14C to 14E located on the traveling direction F side of the vacuum tray 14A. Cleaning devices 26A-2 for supplying a cleaning liquid to the above slurry S cake to wash the cake
6C are able to advance and retreat in the traveling direction F independently of each other. However, in this regard, the above-mentioned Japanese Patent No.
In the vacuum filtration apparatus described in Japanese Patent Application Publication No. 70-210 and Japanese Patent No. 3091200, etc., the slurry supply device and the washing device are made to move forward and backward integrally, so that the supply of the slurry and the washing of the cake are performed. On the other hand, according to the present embodiment, the supply device 15 and the cleaning devices 26A to 26C are moved forward and backward in different time charts without synchronizing, and the supply of the slurry S and the cake Washing can be performed. That is, for example, the supply of the slurry S is performed by slowly moving the supply device 25 in the traveling direction F or one direction toward the rear thereof while the filter cloth 11 is stopped, and the slurry S is evenly distributed on the filter cloth 11. The slurry S is supplied at a uniform thickness so that the supply device 25 is returned to the original position while the filter cloth 11 is running, while the cleaning devices 26A to 26C are provided.
By moving the filter cloth one or more times at a uniform speed while the filter cloth is stopped, a sufficient washing liquid can be supplied to the cake from which the slurry S has been filtered to ensure washing.

Therefore, according to such a vacuum filtration device, the supply of the slurry S by the supply device 15 and the washing of the cake by the washing devices 26A to 26C are thus independent of each other, and the device 1 can be provided in a time chart suitable for each.
5, 26A-26C is advanced and retreated, so that the cleaning device 26A-26C advances and retreats as in the conventional case.
5 is restrained from moving forward and backward, and the slurry S cannot be spread all over the filter cloth 11 or the cleaning device 2
6A to 26C can be prevented from being prevented from being sufficiently supplied to the dewatered cake of the slurry S due to the restraint of the advance and retreat of the supply device 15, and the filter cloth 11 Slurry S with uniform thickness
, And the washing liquid L can be sufficiently supplied to the dewatered cake having a uniform thickness by the slurry S thus supplied, for washing. And by this, it is possible to prevent the unevenness of washing and the partially insufficiently filtered portion from being generated in the finally obtained dehydrated cake, and to obtain a cake having a uniform liquid content and being sufficiently washed. It becomes.

Further, in the present embodiment, when the supply device 15 and the cleaning devices 26A to 26C are independently advanced and retracted, the individual driving means 25 and 27 are connected to each other so as to be advanced and retracted. That is, the supply device 15 and the cleaning devices 26A to 26C can move forward and backward by independent driving means 25 and 27. However,
In this regard, for example, the driving means is common to both devices,
It is also possible to separately move the supply device and the cleaning device forward and backward by interposing a link mechanism or the like between them, but in such a case, the link mechanism becomes complicated and any of the supply device and the cleaning device is used. If one of the time charts is to be changed, the link mechanism must also be replaced, and the operation is inevitably extremely complicated.
According to the vacuum filtration device of the present embodiment in which the driving means 25 and 27 of the 26C are also independent, even when the time chart is changed in this way, the devices 15 and 26A to change the time chart.
Only the driving means 25 and 27 of the 26C need to be controlled in accordance with this, the operation is easy, and the time chart can be changed in a short time.

Further, in this embodiment, each vacuum tray 1
A vacuum suction device is connected to the vacuum suction chamber 19 or the vacuum suction chambers 19A and 19B of FIG.
D is branched into a plurality of branches, so that the vacuum suction chambers 19, 19A, and 19B are connected to the vacuum suction chambers 19, 19A, and 19B at a plurality of locations in the traveling direction F and the width direction of the filter cloth 11, and therefore, these vacuum suctions By generating a uniform vacuum suction force in the chambers 19, 19A and 19B, a uniform vacuum suction force can be applied to the slurry S even from the upper surface portion 18 of the vacuum tray 14 via the filter cloth 11. In addition, these suction pipes 20A to 20D are provided at a plurality of locations at equal intervals on both sides around the center of the filter cloth 11 in the running direction F of the filter cloth 11, and in the width direction of the filter cloth 11 in the vacuum suction chambers 19 and 19A. The vacuum suction chambers 19, 19A, and 19B are also connected to each other at a plurality of locations at equal intervals on both sides of the center portion thereof so that a vacuum suction force is generated evenly in the vacuum suction chambers 19, 19A, and 19B. The vacuum suction force can be applied to the dewatered cake, so that the non-uniform liquid content of the dewatered cake can be more reliably prevented. In this embodiment, the suction pipes 20A to 20A are provided in the vacuum suction chambers 19 and 19A.
The connection points of C are arranged in a lattice shape in a plan view, but they may be arranged in a staggered manner. In contrast to the above-described vacuum suction chamber 19B, the vacuum suction chamber has a width of the filter cloth. For example, when the length is longer in the direction and shorter in the traveling direction, the vacuum suction device may be connected to the vacuum suction device at a plurality of positions only in the width direction.

In this embodiment, the vacuum trays 14A and 14B and the vacuum trays 1
4C and 14D are connected to different suction tubes 20A and 20B, and also in the vacuum trays 14E to 14H.
The vacuum suction chambers 19, 19A and 19B are connected to different vacuum suction devices, that is, the vacuum suction chambers 19, 19A, 1 provided on the plurality of vacuum trays 14.
9B, a part of the plurality of vacuum suction devices provided in the apparatus main body 10 is the other vacuum suction chamber 19, 19A, 19B.
B is connected to a different vacuum suction device. However, at this point, for example, only one vacuum suction device is provided in the apparatus main body, all the vacuum suction chambers of all the vacuum trays are connected to this one vacuum suction device, and a pressure regulating valve is provided in the suction pipe between them. It is also possible to adjust the vacuum suction force of each vacuum suction chamber by providing, for example, but in such a case, this vacuum suction device may become extremely large and rather uneconomical. Needless to say, even if the pressure is adjusted by the pressure adjusting valve, the vacuum suction force is balanced between the vacuum suction chambers while the filtration operation is continued, and frequent re-adjustment is required, thereby deteriorating the work efficiency. In contrast, in the vacuum filtration apparatus of the present embodiment employing the above configuration, the slurry S is supplied and the cake is formed on the rear side in the traveling direction F, and the cake is washed by the next washing devices 26A to 26C. And in the running direction F side vacuum tray 14F
The final dehydration filtration by ~ 14H and the vacuum suction force suitable for each step can be reliably applied to the slurry S. In addition, in the present embodiment, the plurality of vacuum suction devices and the vacuum suction chambers 19, 19A, 19B of the plurality of vacuum trays 14A to 14H are connected to a plurality of vacuum trays 14 from one vacuum suction device. The suction pipes 20A to 20D are connected by branched suction pipes 20A to 20D, and each suction pipe 20A to 20D is connected to an individual vacuum suction chamber 19, 19A, 1D.
9B is also branched into a plurality of branches and connected at a plurality of points as described above, so that the number of vacuum suction devices can be prevented from increasing unnecessarily, and a balance between economy and work efficiency is achieved. Is also possible.

[0032]

As described above, according to the present invention,
By providing an air filter at the end of the vacuum opening pipe connected to the suction pipe connecting the vacuum suction chamber of the vacuum tray and the vacuum suction device, the filtrate is contaminated by atmospheric dust and dust sucked when the vacuum is released. Of course, large noise can be generated when the vacuum is released without increasing the diameter of the vacuum release pipe or the diameter of the vacuum release valve or slowly opening the vacuum release valve. The surrounding environment can be prevented from being impaired, and thereby the working efficiency can be improved by shortening the vacuum release time while preventing the apparatus from being enlarged and costly. Also, if a filter element of this air filter is formed by folding a sheet woven with fibers into a bellows shape, it is possible to secure a large surface area to more reliably collect dust and dust and prevent noise. If the vacuum opening pipe to which the air filter is attached is provided so as to avoid the branch of the suction pipe, further reduction in cost of the vacuum filtration device can be promoted.

[Brief description of the drawings]

FIG. 1 is a side view showing one embodiment of a vacuum filtration device of the present invention.

FIG. 2 is a plan view of the vacuum tray 14 of the embodiment shown in FIG.

FIG. 3 is a sectional view taken along line XX in FIG. 2;

FIG. 4 is a sectional view taken along line YY in FIG. 2;

FIG. 5 is a sectional view taken along the line ZZ in FIG. 2;

6 is an enlarged sectional view of a side portion of the vacuum tray 14 in FIG.

FIGS. 7A and 7B are (A) a partially broken side view and (B) a cross-sectional view of a filter element 24B showing the air filter 24 of the embodiment shown in FIG.

[Explanation of symbols]

10 Device body 11 filter cloth 11A Filtration unit 13 Coating drive 14 (14A-14H) Vacuum tray 15 Supply device 18 Upper surface of vacuum tray 14 18A Flat part at the center of upper surface part 18 18B Wall on the side of the upper surface 18 19, 19A, 19B Vacuum suction chamber 20A-20D suction tube 24 Air Filter 26A-26C Cleaning device F Running direction of filter cloth 11 S slurry L Cleaning liquid

Continuation of the front page (56) References JP-A-4-59005 (JP, A) JP-A-6-156623 (JP, A) JP-A-5-60645 (JP, A) , U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B01D 29/09

Claims (2)

(57) [Claims] 1. A vacuum tray connected to a vacuum suction device is provided under a filter cloth provided so as to be able to travel substantially horizontally in the apparatus main body, and the slurry supplied on the filter cloth is supplied by the vacuum tray. A vacuum filtration device for filtering by vacuum suction through the filter cloth, wherein the vacuum tray and the vacuum suction device are connected via a suction tube, and the suction tube has a vacuum release valve. and vacuum open tube is connected with, the end opposite to between the vacuum release valve and the connection part between the suction pipe of the vacuum opening tube, air filter is provided, the air filter The opening
Face down and place it on the opposite end of the vacuum release tube.
A cylindrical cover with a bottom and a fiber braided
Filled into a cylindrical shape with a sheet folded in a bellows shape
A filter element, the filter element comprising:
Leave an interval between the inner circumference of the cover and the inside of the cover.
The outer periphery of the lower end of the cover is annularly opened.
A vacuum filtration device characterized by being applied. 2. The suction pipe is branched into a plurality of branches.
And the vacuum release pipe is a branch of the suction pipe.
Connected to the suction tube so as to avoid
The vacuum filtration device according to claim 1, wherein: