JPH06277417A - Filter - Google Patents

Abstract

PURPOSE: To enhance the extraction efficiency of soluble or insoluble solids from a solvent and to decrease the amount of a washing liquid to be used for extraction of a prescribed amount of the solids by collecting the washing solvent from a washing section of a lower traveling section, recycling the washing solvent recovered in a compressing means and supplying the washing liquid to filter cake. CONSTITUTION: The belt washing liquid flowing out of a belt washing box 46 is recycled via a pipeline 49 to the washing regions at the top and last of the upper traveling section 30, i.e., nozzles W1 and W5. The washing liquid in a system part where the washing liquid is recycled in a direction backward against the moving direction of the filter cake is supplied to the belt washing box 46 only from the nozzles 47 and 48 and the washing liquid extracted from the recycling system is removed only via pipelines 41 and 42 connected to an eighth vacuum tray from the top at upstream end of the traveling section. The operation of the nozzles 47 and 48 is synchronized with the movement of an endless belt 10 and the consumption of the washing liquid is minimized. On the other hand, the classification efficiency of the insoluble solids and the soluble is maximized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtering device, and more particularly to an endless filter belt, guiding means for guiding a substantially horizontal upper traveling portion and a returning lower traveling portion of the belt, and filtering the upper traveling portion of the belt. A supply means for supplying a slurry to be provided, which is disposed below the upper traveling portion of the belt, and acts to absorb the liquid from the slurry on the upper traveling portion and leave the dehydrated filter cake on the upper traveling portion. The vacuum means and advance means for moving the upper running part of the belt from the upstream end to the downstream end by alternatingly stepping the upper running part and the lower running part of the belt are provided. The present invention relates to a filter device of the endless filter belt type, which comprises a reciprocating guide member provided at a downstream end portion of an upper traveling portion, a one-way means provided to act on a lower traveling portion of the belt, and a tensioning means.

[0002]

BACKGROUND OF THE INVENTION Filtration devices of the above type have been described in earlier British patent application No. 2030465 by the same inventor of the present invention.
Are disclosed in the specification.

Further, the improved device described in detail in the above-mentioned British Patent Application No. 2092905 by the above-mentioned inventor further includes a compression means formed on the upper running portion of the endless filter belt to squeeze out the liquid from the filter cake. It is equipped with. The compressing means is disposed under the upper running portion of the endless belt, and the inflatable bag pushes the belt and the filter cake on the belt upward so as to contact the pressure plate disposed on the upper portion of the belt. It is in the form of a drainage grid that is applied. Furthermore, earlier British patent application No. 209076 by the same inventor as the present invention
No. 4 discloses a means for supplying a cleaning liquid containing a cleaning liquid to be recirculated from a vacuum means to a filter cake formed on the upper running part of the endless filter belt, and a cleaning liquid on the surface part of the lower running part of the belt. Means for directing a jet stream to clean the undercarriage are disclosed.

A device of the above type comprises some equipment for separating solids from a fluid. For example, it is used to separate soluble solids from a mixture of liquid and solids. Specific examples of this are, for example, the extraction of sugar from sugar beet or sugar cane, or the extraction of coffee, lignin or dyes. Conventionally, for example, prior to separating the soluble solids from the liquid phase using a filtration device of the type described in detail above, the solids contained in the soluble solids are disintegrated and stirred in a solvent, otherwise for a predetermined time, It is made to react.

In general, it is insoluble by the same solvent or other washing solvents which are additionally supplemented depending on the products on the market to improve the extraction of the soluble solids and / or the purity of the insoluble residual solids. A "wash" of solids is performed.

In the current commercial era, commercial products, whether soluble or insoluble, have become increasingly popular with increasing awareness of the need for economy, efficiency and reduced negative environmental impact. There is an increasing demand for improved production rates and purities. In filtration devices of the above type, a major need is also to be able to extract large amounts of soluble solids with a minimum amount of solvent or wash solution. Furthermore, it is necessary to perform the cleaning operation when the belt is not running as efficiently as possible without impairing the filtration efficiency and running of the belt, and to minimize the amount of solvent or cleaning solution used in the cleaning operation. There is.

The conventional cleaning method, as already mentioned, uses a high pressure jet of cleaning solution. However, since the cleaning action of a solvent is proportional to its pressure, solvent usage has hitherto been determined more exclusively by the required pressure level than by other factors. Therefore, a large amount of cleaning solvent had to be used for cleaning the filter cake and subsequent cleaning of the belt. Further, the amount of the soluble or insoluble solid extracted from the washing solvent thereafter is small, which is a problem per se.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to enhance the extraction efficiency of soluble or insoluble solids from a solvent in a filtration device of the above type and to use a washing liquid for extracting a predetermined amount of solids. The purpose is to reduce the amount significantly than was required in the conventional type.

[0009]

According to the present invention, there is provided a filtration device of the type described above, wherein each continuous section of the upper running portion of the endless filter belt for cleaning the filter cake adhering to the upper running portion thereof. A belt cleaning means for supplying a cleaning solvent to the upper running portion, each of which is arranged on the upper part of each divided area of the upper traveling portion, and each has a plurality of perforated plate members and the perforated plate member when the filter cake in each area is compressed. Having a means for supplying gas through it, applying a pressing force to the filter cake attached to the upper traveling portion, a plurality of compression means, and cleaning the belt at the lower traveling portion of the endless filter belt and traveling downward. Washing solvent is collected from the washing section of the cleaning section and the collected washing solvent is recirculated to at least one of the compression means to supply the washing solution to the filter cake. Constituted by the means.

[0010]

The present invention will be described in detail with reference to the accompanying drawings, which show representatives of the preferred embodiments.

As shown in FIG. 1, the filtration device of the present invention comprises:
The endless filter belt 10 is mounted in a housing 50 that can be hermetically sealed during operation. The endless filter belt 10 comprises a series of rollers 12, 14, 1
The upper running portion 30 is mounted so that it can be guided around 6 and 18, and the lower portion of the guide rod 20 can be dragged together, and extends substantially horizontally between the guide rod 20 and the roller 12 and the return lower portion. The running portion 40 is formed.
In use, as shown in FIG. 1, the upper traveling portion 30 moves from the right side portion to the left side portion, while the lower traveling portion 20 moves from the left side portion to the right side portion, and the guide rod 20 is arranged above. The upstream end of the traveling unit 20 and the arrangement of the rollers 12 are the downstream end of the upper traveling unit.

As shown in FIGS. 3 and 4, the roller 12 mounted between the swinging arms 22 at the downstream end of the upper traveling portion 30 of the endless filter belt 10 is a main driving roller. The arm 22 is attached to and suspended from a rotating shaft 24 extending through the side wall of the housing 50. When the shaft 24 rotates, the arm member 22 swings together with the guide roller 12 from the position shown by the solid line to the position shown by the broken line as shown in FIG. 1, and the endless filter belt moves from the right side to the left side in FIG. The upper traveling unit 30 of 10 is stepped. The guide roller 14 in the lower traveling portion 40 constitutes a second drive roller which is belt-driven by the motor 26 and is intermittently driven. In addition, the ratchet 28 attached to one end of the guide roller 14
And a one-way mechanism section including the claw 32 combined with the one-way mechanism section. The claw 32 cooperates with the ratchet 28 to move the lower traveling portion 40 of the endless filter belt 10 only in the direction from the right side portion to the left side portion in FIG. In this way, when the main drive roller 12 is swung and moves to the position shown by the broken line, the upper traveling unit 30 steps forward without slightly moving the belt member of the lower traveling unit 40 backward. The roller 16 is a tension roller that is biased by a spring force. The roller 16 reciprocates back and forth at the curved portion of the belt between the rollers 14 and 18 to tighten the slack of the belt, and the belt tension during the reciprocating movement of the main drive roller 12 is reduced. Maintained.

In the operation of the above apparatus, the upper running portion 30 of the endless filter belt 10 is intermittently advanced to the broken line position by the swing of the main drive roller 12. Upper running part 3
In the stationary phase in which 0 is alternated, the lower traveling unit 40 is pulled from the left side portion to the right side portion, and the main drive roller 12 is pulled back to the solid line position without resistance. When the main drive roller 12 moves to the broken line position, the tension roller 16 is biased by the spring reaction force of the spring member 34. When the second driving roller 14 pulls the belt via the lower traveling portion 40 during the alternating movement of the upper traveling portion 30, the tension roller 16 moves and the spring member 34 acts to increase the curved portion again. The tension roller 16 may move one end arranged in a track (not shown) substantially horizontally or in an inclined manner. The spring member 34 may be a gas spring or a pneumatic cylinder. Other suitable spring means may be used.

The upper running portion 30 of the endless filter belt 10.
A plurality of vacuum trays are arranged at the bottom of the. In the illustrated embodiment, 15 vacuum trays (hereinafter also referred to as vacuum boxes) V1 to V15 are provided. The number of vacuum trays installed may be changed. These vacuum trays V1 to V1
5 is connected to one or more suction pumps (not shown) in a manner well known in the art.

A slurry supply station S is provided adjacent to the guide rod 20 at the upstream end of the upper traveling portion 30. At this station S, a slurry or suspension of solids and liquids to be separated is supplied to the upper surface of the upper running part 30 of the endless filter belt 10. This is done by means of a supply pipe or outflow or other suitable supply means capable of supplying the slurry layer in the upstream end region of the upper running part 30.

In the present specification, the separation or filtration treatment is also referred to as "dehydration treatment", but the water to be removed is almost pure water, not the mother liquor and / or the washing solution.

At the downstream end of the belt in the slurry supply station S, the cleaning solvent is supplied to the upper traveling section 30 by a plurality of cleaning solvent supply means, preferably in the form of nozzles. In the illustrated embodiment, five cleaning solvent supply means W1 to W5 are provided, and the supply means W5 adjacent to the downstream end of the upper traveling portion 30 is composed of several nozzles.

A plurality of compressors are arranged above the upper running portion 30 of the endless filter belt 10. In the example shown, six compressors P1, P6 are provided. The compressor P1 is arranged between the slurry supply station S and the upstream end cleaning solvent supply nozzle W1. Other compressors P2
P5 is a continuous cleaning solvent supply nozzle W1 to W5
When the filter cakes formed on the upper traveling portion 30 pass by as they are arranged at positions further apart on the downstream side with a space therebetween, and thus the upper traveling portion 30 advances intermittently, The washing solvent and the filter cake are alternately compressed.

Each vacuum tray V1-V15 has its own outlet, and several groups of adjacent vacuum trays are connected to a common outlet pipe 41-45, respectively. In this case, the respective vacuum trays below the cleaning solvent supply region of the belt and the vacuum trays below the respective compressors that are continuous toward the downstream end of the upper traveling portion 30 are connected to a common outflow pipe. In the above embodiment, the slurry supply station S, the first cleaning solvent supply means W1 and the lower two vacuum trays V1 to V6 of the first compressors P1 and P2 are connected to the common outlet pipe 41, and the second vacuum trays V1 to V6 are connected. Vacuum trays V7 and V8 below the cleaning solvent supply means W2 and the compressor P3, respectively, are commonly connected to the outlet pipe 42, and vacuum trays V9 below the cleaning solvent supply means W3 and the compressor P4, respectively. And V10 are connected to a common outlet pipe 43, and the vacuum trays V11 and V12 below the fourth cleaning solvent supply means W4 and the following compressor P5 are commonly connected to the outlet pipe 44.
Vacuum tray V13 below each of the fifth cleaning solvent supply means W5 and the compressor P6 following it.
~ V15 are commonly connected to the outlet pipe 45. In each case, the compressors P1 to P6 remove the free water vapor from the filter cake to the maximum extent before the cleaning solvent is supplied, and the vacuum connection mechanism described above prevents the extraction liquid from being continuously mixed. To do. This is important for maximizing the liquid extraction efficiency of the entire system and minimizing the amount of wash solvent in the entire system so that some of the extracted or filtered liquid is recycled. Is.
For example, in the illustrated embodiment, the outlet pipe 45 recirculates the cleaning solvent extracted in the final cleaning and compression stage at the downstream end of the upper traveling section 30 to the adjacent cleaning solvent supply nozzle W4 on the upstream side, Similar to the outlet pipe 45, the outlet pipes 44 and 43 recirculate the cleaning solvent to the cleaning solvent supply nozzles W3 and W2, which are directly adjacent to each other upstream of the belt region where the cleaning solvent is extracted.

The upper running portion 30 of the endless filter belt 10.
At the downstream end adjacent to the main drive roller 12 in, the dewatered filter cake is discharged from the belt in a simple drop manner or with the aid of a doctor blade (not shown).

In the lower traveling section 40, the endless filter belt 10 passes through a belt cleaning box 46, and high pressure spray nozzles 47 and 48 arranged at the upper and lower portions of the belt 10 are provided on both sides of the belt cleaning box 46. The cleaning liquid is sprayed toward the to completely remove any solid substances or solid particulate substances adhering to the porous woven fabric of the belt 10 for washing. After passing through the belt cleaning box 46, the belt 10
Passes over a plurality of suction nozzles (not shown), and these suction nozzles absorb moisture from the belt 10 and dry it in preparation for the subsequent running of the belt 10.

As shown in the drawing, the belt cleaning liquid flowing out from the belt cleaning box 46 is washed through the pipeline 49 at the leading and trailing washing regions of the upper traveling portion 30, that is, the nozzle W.
1 and W5. About 80% of the recirculated belt cleaning liquid flows through the nozzle W5, and the remaining about 20% flows through the nozzle W1. This distribution is performed by a needle valve provided at a position beyond the nozzle W5 in the pipeline 49 or a portion having an appropriately small pipe diameter provided at the position.

In the illustrated countercurrent recirculation line, that is to say the line in which the washing liquid is recirculated in the direction opposite to the direction of movement of the filter cake, the clean washing liquid is supplied to the nozzle 4
The cleaning liquid, which is supplied to the belt cleaning box 46 only from 7 and 48, is extracted from the head of the upstream end of the running portion from the beginning of the cleaning liquid 8
Pipelines 41, 42 connected to the th vacuum tray
Only removed via. The supply amount of the cleaning liquid is carefully adjusted, and the operation of the nozzles 47 and 48 is simply synchronized with the movement of the endless filter belt 10, so that the usage amount of the cleaning liquid is minimized while the insoluble solid is used. And the fractionation efficiency of soluble solids in the wash liquor is maximized.

Although it is not clear from the schematic configuration diagram of FIG. 1 simplified to show the schematic configuration of the arrangement of the constituent parts of the above-mentioned apparatus, each of the pipelines 41 to 45 includes a cleaning liquid receiver, and each of the cleaning liquids. The receiver is connected to a suction pump. An example of the cleaning liquid receiver 60 is shown in FIG.

As shown in FIG. 9, the cleaning liquid receiver 60 is a closed container having an inlet 61 for receiving the cleaning liquid from each vacuum tray, and at the lower end thereof (in the above pipelines 41 and 42, It has an outlet 62 for recirculation to supply cleaning liquid to each cleaning liquid nozzle upstream for collection, preferably further processing), and at its upper end a vacuum member such as a suction pump as described above. Has a port 63 that is permanently connected to the valve and another port 64 that is equipped with a valve R1 that is connected to a ball cock 65. Exit 6
2 is connected to a pump 66 that is always in operation, and the pump 66 is connected to an outflow pipe 67. Check valve R
2 is connected to the pipe 67 via a branch pipe 68 connected to the valve R1. During operation, the cleaning liquid flows into the inlet 61, and if the amount of inflow is an appropriate amount, it is discharged by the pump 66. On the other hand, when the pumping speed of the pump 66 exceeds the inflow rate of the cleaning liquid, the ball cock 65 descends to open the valve R1. This causes the discharge side of the pump 66 to be in a vacuum state and the check valve R2 to close, so that instead of pumping out the filtered cleaning liquid, the cleaning liquid is returned via the branch pipe 68 until the cleaning liquid level in the receiver rises again. Therefore, the ball cock 65 rises to close the valve R1. Practically, the valve R1 is maintained in a slightly opened state rather than being opened / closed so that the cleaning liquid is sufficiently returned from the branch pipe 68 so that the liquid level in the receiver 60 is kept constant. To be In this way, the cleaning liquid is delivered to each nozzle and the collecting pipe in the upstream portion at a constant flow rate, and the outflow amount of the delivery liquid per unit time changes only in accordance with the inflow flow rate of the cleaning liquid. In this way, effluent and influent equilibrium, which is an important requirement when recirculating the wash liquor, is automatically achieved.

Further, in each of the pipelines 41 to 45, a valve device (not shown) is arranged upstream of the receiver in the inflow direction of the cleaning liquid (for example, British Patent No. 2203521 by the same inventor as the present invention). Each of the pipelines and the vacuum trays connected to the pipelines are used as the above-mentioned receivers, from which the vacuum or the atmosphere can be connected. In this way, the selected vacuum tray can be connected to the vacuum or the atmosphere by switching the valve device.

A pump (not shown) is provided in the pipeline 49 to feed the belt cleaning box 46 to the supplying means W1.
The cleaning liquid is supplied to W2. In some cases, it is preferably a diaphragm pump capable of dry operation, and its pumping flow rate exceeds the inflow flow rate from the belt cleaning box 46 in some stages. The cleaning liquid is discharged from the belt cleaning box 46 via a regulating valve or simply a restriction opening. The pipeline 49
In addition, along with the above-mentioned pumps constituting the pump 66 in FIG. 9, a receiver similar to that shown in FIG. 9 but not connected to the vacuum is provided to make the flow rate of the cleaning liquid in the nozzles W1 and W5 sufficient. It is advantageous to do so.

The vacuum trays V1 to V15 are preferably of the type shown in FIG. Regarding this vacuum tray, the vacuum tray indicated by reference numeral V in FIG. 8 has a predetermined cross-sectional area due to the inclined side wall portions 70, 71 and the grid 72 fitted to the tray base portion with a certain distance from the bottom wall portion 73. And has a bottom wall portion 73
An outlet portion 74 is formed in the. As shown, an endless filter belt 10, or rather a short portion of the belt 10, covers the vacuum tray V and extends between the sloped sidewalls 70 and 71. By inclining both side wall portions 70 and 71, it becomes easy to capture the belt during movement, that is, to maintain the belt arrangement, and liquid or solid is prevented from leaking from the upper surface of the belt.

A method of reciprocating the main drive roller 12 and other guide rollers 1 according to FIGS.
A method of mounting 4 to 18 in the airtight housing 50 will be described. The main drive roller 12 is reciprocated by both auxiliary swing arms 36. Each swing arm 36 has a shaft 2
4 is fixed to a portion of the housing 50 projecting outward, and is swung by pneumatic rams 38 fixed to the outside of both sides of the housing 50. Guide rollers 14-1
Both ends of 8 are journaled by bearings 25 mounted on both outer sides of the housing 50. Each bearing 25 is sealed by a flanged cover 27 attached via a gasket 29.

6 and 7 show an example of a compressor of the type used as the compressors P1 to P6 in the apparatus of FIG. In FIGS. 6 and 7, the vacuum tray 52 shown below the filter belt F is of a type different from that shown in FIG. This exemplary compressor includes a fixed mounting plate 53 located on top of the filter belt 10,
An array support plate 54 is fixed to the lower part of the belt 10 and is fixed immediately below the vacuum tray 52 having a plurality of channels 59 on the upper surface thereof. The movable pressure plate 55 has a perforated front wall portion 56, and the front wall portion 56 is connected to the front wall portion 56 via a column 58 which is loaded with a spring force.
It is mounted so as to face 0 and an expansion element 57 is interposed between the pressure plate 55 and the fixed plate 53. In use, as is apparent from FIG. 7, the expansion element 57 urges the movable pressure plate 55 to be pushed down to urge the belt 10 to move.
Compress the filter cake F formed above. At the same time, compressed gas such as air is supplied to the chamber formed in the pressure plate 55 and is discharged through the through holes of the front wall portion 56. By supplying gas in this way, the filter cake F is dehydrated, and further the cake F
It is possible to promote atomization of the liquid captured between the solid particles constituting the. On the other hand, in the compression operation, if the compression operation is not performed, the liquid may escape, but since the liquid flow passage in the escape filter cake is closed, it cannot be said that the dehydration rate is not necessarily increased, and the filter cake It has been found that the dehydration rate can be improved by 25% by blowing gas onto the cake simultaneously with compression.

When the housing 50 is to be made airtight during the operation of the above apparatus, a rotary valve or a rotary seal is used to open the opening of the surrounding wall portion shown on the lower left side of FIG. The filter cake dropped from the downstream end of the upper traveling unit 30 is intermittently passed through the opening. Instead of such a rotary valve or rotary seal, a series of three valves are used, and two valves are cascaded in sequence.
Close one valve and open one valve,
The filter cake may be passed through the open valve. In this way, the pressure within the housing 50 is maintained.

A series of operations of the above-configured apparatus are as follows: As already explained, in order to move the upper traveling section 30 forward at a rate of several times per minute, the arm 38 is operated, The drive roller 12 is swung to advance to the position indicated by the broken line. For example, the upper traveling unit 30 is 5 to 15 per minute.
Perform forward movements. The forward motion time is several seconds, and then the upper traveling unit 30 is stationary for a few seconds, during which the lower traveling unit 40 moves through the motor 26 until the upper traveling unit 30 is advanced again. Be withdrawn. The upper traveling portion 30 has a length of, for example, 5 to 15 m, and it takes about 2 to 10 minutes to intermittently transfer a predetermined portion of the belt from the upstream end portion to the downstream end portion as described above.

On the other hand, the endless filter belt 10 is
Instead of several times per minute, for example, several times per minute, or at a speed less than or equal to 3 minutes, a certain part of the belt is transmitted to the upper running part 30 to complete the transfer. It will take a considerable amount of time to complete the cycle.

During the stationary phase of the upper traveling portion 30, the slurry is supplied at the position S, the vacuum trays V1 to V15 are connected to the vacuum portion, and the compressors P1 to P6 are brought into the operating state shown in FIG. The continuous part on the downstream side is actively dehydrated. Further, the housing 50 is closed so that the air pressure inside the housing 50 is slightly increased.

The supply of the slurry is stopped by the time the upper running portion 30 is advanced by one step, and the suction pressures of the vacuum trays V1 to V15 connect the pipelines 41 to 45 to the atmospheric pressure via the valve devices as described above. By doing so, the pressure plates 55 of the compressors P1 to P6 are lifted to the positions shown in FIG. If the housing 50 is under pressure, the pressure is released by ventilation. These series of operations are controlled by one or more timers. The timers are automatically set or reset each time the pneumatic ram 38 is activated. Preferably,
Each time the belt advances one step, a distance corresponding to one length of the vacuum trays V1 to V15 can be pulled through the upper traveling unit 30. Every time the upper traveling unit 30 stops, the slurry supply operation is stopped and the vacuum pressure and the compression force are repeatedly applied under the control of the timer.

When the slurry supply is restarted during the stationary phase of the upper traveling portion 30, the second driving roller 14 pulls the main driving roller 12 back to the position shown by the solid line, and at the same time, the lower traveling portion 40 cleans the belt. Pulled through the box 46. The nozzles 47 and 48 are the second drive roller 14 described above.
Is switched in synchronism with the operation of the cleaning box, and the speed of pulling down the belt 10 through the cleaning box 46 is adjusted so that the cleaning is effectively performed. As soon as a predetermined portion of the belt 10 is passed through the wash box 46, the nozzles 47 and 48 are
Is switched off again.

As described above, the cleaning nozzles 47 and 48
Cleaning solution sprayed from is collected and pipeline 4
The cleaning liquid is recirculated via 9 to the first and last nozzles W1 and W8 for the upper traveling section 30.

The present invention is not limited to the embodiments described above, and the embodiments are merely examples for explaining the present invention.

FIG. 2 shows that, depending on the substance to be treated,
Another belt cleaning method is shown which can be applied instead of or in addition to the cleaning box 46 with spray nozzles 47 and 48 as shown in FIG. As shown in the drawing, the lower traveling portion of the belt passes through the soaking tank 146 via the rollers 91 to 94 and the main drive roller 1
When the 2 swings toward the broken line position, the rollers 9
The lower traveling unit is guided by a ratchet 95 and a pawl 96 mounted on the leading roller 91 of the 1 to 94, while preventing the lower traveling unit from returning from the right side to the left side via a one-way mechanism unit typically shown. When used alone, the cleaning liquid or cleaning solvent is supplied only to the soaking tank 146,
It is progressively discharged and recycled through pipeline 149 in a manner similar to that shown in FIG. When used in combination with the belt cleaning box 46, the cleaning liquid is individually supplied to the cleaning box 46 and the soaking tank 146 and recirculated from one or both of them (46, 146). In this way, the solvent used in the soaking tank 146 is the same as the cleaning solvent used in the belt cleaning box 46 or for cleaning the filter cake on the upper traveling portion.

The other components of the apparatus shown in FIG. 2 are the same as those shown in FIG. 1 and are designated by the same reference numerals.

In any case, according to the present invention, as long as the belt cleaning liquid is recirculated, it does not hinder the supply of the clean cleaning liquid for cleaning the filter cake in the upper traveling portion in at least one cleaning stage.

The constituent parts of the apparatus having the above-mentioned structure can be modified in various ways, one example of which will be described below. The main driving roller 12 may be reciprocated by a swingable arm member mounted on a pivot under the filter belt, or may be reciprocated by directly connecting to a ram of a pneumatic or hydraulic cylinder. The housing surrounding the device does not necessarily have to be hermetic. The compressor may have a pressure plate driven by, for example, a hydraulic or pneumatic ram or other bellows or diaphragm, instead of the expansion element as shown. The means for tensioning the lower traveling portion is capable of reciprocating vertically in the slack portion of the belt, and requires the second driving means in the lower traveling portion even if the main driving roller cannot be pushed forward strongly. Instead, a roller member having a sufficient weight to pull the lower traveling portion can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic side view of a filtration device according to a preferred embodiment of the present invention.

FIG. 2 is a partial enlarged view of a belt cleaning unit corresponding to the left side portion of the apparatus of FIG. 1, which is a modification of the present invention.

FIG. 3 is a sectional view taken along line III-III in the apparatus of FIG.

FIG. 4 is a partial side view of a drive mechanism section that reciprocates a main drive roller in the above apparatus.

FIG. 5 is a partial cross-sectional view of a support mechanism portion at both ends of a guide roller of an endless filter belt.

FIG. 6 is a cross-sectional view of the compressor with a pressure plate in a raised position when not in operation.

7 is a cross-sectional view of the compressor shown in FIG. 6 with the pressure plate in the lowered position during operation.

FIG. 8 is an enlarged sectional view of a vacuum tray applicable to the apparatus of FIG.

9 is a schematic configuration diagram of a receiver connected to a pipeline connected to each vacuum tray in the apparatus of FIG.

[Explanation of symbols]

 10 Endless Filter Belt 12 Main Driving Roller 14, 18 Guide Roller 16 Tension Roller 20 Guide Rod 22 Arm 24 Shaft 25 Bearing 26 Motor 27 Flanged Cover 28 Ratchet 29 Gasket 30 Upper Traveling Part of Endless Filter Belt 32 Claw 34 Spring Member 36 Swing Moving arm 38 Pneumatic ram 40 Lower running part of endless filter belt 41-45 Pipeline 46 Belt cleaning box 47, 48 Cleaning nozzle 49 Pipeline 50 Housing 55 Movable pressure plate 57 Expansion element 58 Strut 59 Channel 60 Cleaning liquid receiver 65 Ball Cock 66 Pump 68 Branch pipe 70, 71 Inclined side wall 72 Grid 73 Bottom wall 74 Outlet 91-94 Roller 95 Ratchet 96 Claw 146 Soaking tank 6 Lower run 61, 62 and 63 guide rollers of the endless filter belt, 74 F filter cake P1~P6 compressor S slurry feed station V1~V15 vacuum tray W1~W5 cleaning nozzle

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B01D 33/58

Claims (10)

[Claims] 1. An endless filter belt; guide means for guiding the endless filter belt so that the endless filter belt forms a horizontal upper traveling portion and a lower traveling portion, and the upper end traveling portion of the endless filter belt should be filtered. First supply means for supplying a slurry; disposed below the upper traveling portion of the endless filter belt, adsorbing liquid from the slurry on the upper traveling portion through the filter belt portion, and leaving a filter cake on the filter belt portion. Vacuum means that acts so as to supply a cleaning liquid to the continuous sectioned region of the upper running portion of the endless filter belt to wash the filter cake attached to the continuous sectioned region of the upper running portion,
A plurality of second feeding means; a reciprocating motion guide member arranged at a downstream end of the upper traveling portion of the endless filter belt, a one-way mechanism member and a tension member provided so as to act on the lower traveling portion, and Feeding means for moving the upper traveling portion and the lower traveling portion in an alternating manner from the upstream end toward the downstream end; cleaning means for cleaning the filter belt portion of the lower traveling portion and the filter belt. A belt cleaning means for collecting cleaning liquid from a portion and recirculating it to the plurality of second supply means; and a compressor arranged at a space above the upper traveling portion, wherein the perforated pressure plate and the compressor are provided. A means for supplying gas at the time of compressing the filter cake through a perforated pressure plate is provided, and the second supply is provided in the continuous section area of the upper running portion of the endless filter belt. A filtration device comprising a plurality of compression means for compressing the filter cake remaining in each continuous section of the upper traveling portion while supplying the cleaning liquid from the supply means. 2. A cleaning liquid is recirculated from a belt cleaning section of a lower traveling section of an endless filter belt to at least two belt cleaning section areas of an upper traveling section, one of the cleaning section areas being upstream of the upper traveling section. The filtering device according to claim 1, wherein the filtering device is sent toward the end, and the other is sent toward the downstream end of the upper traveling portion. 3. The flow rate of the cleaning liquid recirculated from the belt cleaning section of the lower traveling section of the endless filter belt to the downstream end section of the upper traveling section is greater than the flow rate of the cleaning solution recirculated to the upstream end section of the upper traveling section. The filtering device according to item 2. 4. About 80% by volume of the cleaning liquid recirculated from the belt cleaning part of the lower running part of the endless filter belt.
Is filtered to the downstream end of the upper run and about 20% by volume is recycled to the upstream end of the upper run. 5. The upstream and downstream ends of the upper running portion of the endless filter belt via a needle valve provided in a pipeline for supplying the recirculated cleaning liquid to the second supply means. The filtering device according to claim 3, which is distributed. 6. The recirculating cleaning liquid supply of the second supply means for supplying the cleaning liquid recirculated from the belt cleaning part of the lower running part of the endless filter belt to the upstream end and the downstream end of the upper running part. The filtration device according to claim 3, wherein the filtration devices are distributed through different pipe diameter portions formed in the pipeline. 7. The cleaning liquid sucked by at least some vacuum means arranged toward the downstream end of the upper running portion of the endless filter belt supplies the cleaning liquid to the filter belt portion further upstream of the vacuum means. The filtration device according to claim 1, wherein the filtration device is recycled to the second supply means. 8. The vacuum means is constituted by a vacuum tray having a plurality of individual outlets, and is arranged below each divided area to which the cleaning liquid is supplied by each second supply means in the upper running portion of the endless filter belt. At the same time, one or a plurality of vacuum trays arranged under the respective compression means arranged toward the downstream end of the upper traveling section are commonly connected to the discharge flow path, so that the cleaning liquid sequentially extracted is regenerated. 8. The filtration device according to claim 7, wherein the filtration device is individually collected for circulation or other uses. 9. The filtering device according to claim 1, wherein a reciprocating motion guide means arranged at a downstream end portion of an upper running portion of the endless filter belt is mounted on a swingable arm member. 10. An airtight housing is provided, and an endless filter belt, a belt guiding means, first and second feeding means, a vacuum means, a feeding means, a cleaning means and a compression means associated with the belt are housed in the housing. The filtering device according to item 1.