JP2003033607A - Filter and filtration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter and a filtration method in which compression filtration is carried out by controlling the electric current to be inputted to a pressure controlling valve to control compression pressure according to the prescribed operation pattern. SOLUTION: When a movable plate 4 is pressed against a filter medium 1, the compression pressure is changed by controlling the electric current to be inputted to the pressure controlling valve 55, which is used for controlling the oil pressure to be transmitted from a hydraulic pump 50a to the sides of the upper and lower hydraulic driving cylinders 51, 52 of the plate 4, according to the hourly quantity of the pressure to be changed and the elapse of the compression time which are calculated from the operation pattern showing the relation between the compression time and the compression pressure.

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 a filtering method in which a filter medium is closed in a bag shape and then a stock solution is supplied into the filter medium for filtration.

[0002]

2. Description of the Related Art Conventionally, various types of filtration methods have been proposed.

For example, Japanese Patent Laid-Open No. 3-38209 discloses that
After closing the lower end of the tubular filter medium into a bag shape, the stock solution is supplied into the filter medium, and when the movable plate is moved horizontally to perform squeeze filtration, the squeezing pressure increasing step and the squeezing pressure holding step are sequentially performed. Some are configured for repeated press filtration.

[0004]

However, in the conventional filtration method described above, it is necessary to repeat the squeezing pressure increasing step and the squeezing pressure holding step a considerable number of times before squeezing and filtering to a predetermined squeezing pressure. There was a problem that there was a case where it was damaged and had to be replaced. Further, if the squeezing pressure is increased to a large extent at first, a large force is applied to the filter medium, which may damage the filter medium.If the squeezing pressure increasing process is made small and the above process is repeated more times, the solenoid valve is damaged more quickly. There was a problem of becoming.

Further, in the filtering device disclosed in Japanese Patent Laid-Open No. 4-317704, the movable plate is tilted to widen the lower filter chamber, but a thick cake is generated in the lower part.
There was a problem that a cake with a uniform water content could not be generated in the upper and lower parts.

Therefore, an object of the present invention is to solve the above problems and to control the input current of the pressure control valve to control the squeezing pressure to a predetermined operation pattern to perform squeeze filtration. And a filtration method.

[0007]

In order to achieve the above object, the present invention is configured as follows.

According to the first aspect of the present invention, a cylindrical filter medium having a lower part closed and a stock solution to be filtered contained therein, and an upper part closed, a support for supporting the filter medium, and the support A movable plate that presses the filter medium in a state where the lower portion and the upper portion of the filter medium supported by the above are closed; and the filter medium in a state in which the lower portion and the upper portion of the filter medium supported by the support are closed. A receiving plate that is sandwiched between the pressing plate and pressed to press and filter, a first opening / closing device that can close the lower part of the filter medium supported by the support, and an upper part of the filter medium supported by the support. In a filtering device including a second opening / closing device capable of closing the valve, and two upper and lower hydraulic cylinders that drive the movable plate, a hydraulic pump and the driving force from the hydraulic pump are switched and controlled to the upper hydraulic cylinder. Upper side for selective transmission Switching device, a lower switching device for switching and controlling the driving force from the hydraulic pump and selectively transmitting the driving force to the lower hydraulic cylinder, and a hydraulic pump from the hydraulic pump to the upper hydraulic cylinder side and the lower hydraulic pressure. The pressure control valve that controls the hydraulic pressure transmitted to the cylinder side and the input current that is input to the pressure control valve are set as the amount of pressure change and compression per time calculated from the operation pattern that indicates the relationship between the compression time and the compression pressure. Controlling according to the passage of time, according to the passage of the pressing time according to the passage of the operation pattern based on the operation pressure control unit for controlling to vary the pressure, characterized by including a filtering device. provide.

According to the second aspect of the present invention, in setting the filter chamber volume of the filter medium before squeezing and filtering, the movable plate is tilted so that the lower part is narrower than the upper part of the filter chamber for squeezing and filtering. At the end of filtration, the upper and lower parts of the filter chamber are set to have the same volume so that a cake having a uniform water content is produced.
According to another aspect of the present invention, there is provided a filtration device.

According to the third aspect of the present invention, the control section makes the rate of increase of the squeezing pressure in the first half of the squeezing step smaller than the rate of increase of the squeezing pressure in the latter half of the squeezing step. A filtration device according to an aspect is provided.

According to the fourth aspect of the present invention, the lower portion of the cylindrical filter medium supported by the support is closed, the stock solution to be filtered is contained in the filter medium, and the upper portion of the filter medium is closed, In a filtering method in which the filter medium is sandwiched between a receiving plate supported by a support and the movable plate and the filter medium is pressed and squeezed and filtered, when the filter medium is pressed by the movable plate, the hydraulic pump moves the movable plate. Using the hydraulic pressure transmitted to the upper drive hydraulic cylinder side of the plate and the lower drive hydraulic cylinder side of the movable plate, the movable plate presses the filter medium and the hydraulic pump drives the upper part of the movable plate. Operation pattern showing the relationship between the squeezing time and the squeezing pressure of the input current input to the pressure control valve for controlling the hydraulic pressure transmitted to the hydraulic cylinder side for driving and the hydraulic cylinder side for driving the lower part of the movable plate. Filtration, which is controlled according to the amount of transformation per unit time calculated from the above and the elapse of the pressing time, so that the pressing pressure based on the operation pattern is changed in accordance with the elapse of the pressing time. Provide a way.

According to the fifth aspect of the present invention, in setting the filter chamber volume of the filter medium before the squeeze filtration, the movable plate is tilted so that the lower part is narrower than the upper part of the filter chamber to perform the squeeze filtration. At the end of filtration, the upper and lower parts of the filter chamber are set to have the same volume to form a cake having a uniform water content.
The method for filtering according to the above aspect is provided.

According to the sixth aspect of the present invention, the control unit makes the rate of increase of the squeezing pressure in the first half of the squeezing step smaller than the rate of increase of the squeezing pressure in the latter half of the squeezing step. A filtration method according to an aspect is provided.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to FIGS.

The filtering device 10 according to this embodiment is shown in FIG.
As shown in FIG. 2, the tubular filter medium 1 is suspended and supported on the support body 2 through a suspending member such as a support cord, and the lower end opening of the filter medium 1 is a first opening / closing cylinder 6 as an example of a first opening / closing device. After being closed by driving, the stock solution is supplied into the filter medium 1 through the upper end opening of the filter medium 1, and the upper part of the filter medium 1 is closed by driving the second opening / closing cylinder 7 as an example of the second opening / closing device. By driving the upper and lower hydraulic cylinders 51 and 52, the movable plate 4 presses the filter medium 1 containing the stock solution to perform squeeze filtration, while the first opening / closing cylinder 6 closes the lower end of the filter medium 1 after the filtration is completed. Is opened to open the lower end opening and the cake in the filter medium 1 is discharged by the screw conveyor 18 below the filter medium.

A second opening / closing cylinder 7 and a first hydraulic cylinder 51 are arranged in the horizontal direction above the support 2, and a second hydraulic cylinder 52 is provided below the support 2.
And the first opening / closing cylinders 6 are arranged in the horizontal direction.

The sidebars 21 are provided on both sides of the support member 2 and the movable plates 4 are supported by the sidebars 21 and 21 via rollers 41 provided rotatably on both sides of the movable plate 4. is doing.

The first opening / closing cylinder 6 is provided with a lower tightening bar 61 at the tip of its piston rod so as to engage with an engaging portion 32 formed at the lower end of the receiving plate 31 of the fixed plate 3. I have to. Therefore, the filter medium 1 is attached to the lower tightening bar 61.
The lower end portion of the filter medium 1 is sandwiched between the receiving plate 31 and the receiving plate 31 and is locked to close the lower end opening of the filter medium 1.

The second opening / closing cylinder 7 is provided with an upper tightening bar 71 at the tip of its piston rod so that it can be locked to the locking portion 33 formed at the upper end of the receiving plate 31 of the fixed plate 3. I have to. Therefore, the filter medium 1 is attached to the upper tightening bar 71.
The upper part of the filter medium 1 is closed by sandwiching and locking the upper part of the filter medium 1 between the above and the receiving plate 31.

Hydraulic cylinder 5 as the drive unit 5
One end of each of the pistons 1, 52 is fixed to the support body 2, and the tip end of each piston rod is pivotally attached via a pin to be connected to the upper and lower portions of the movable plate 4, respectively. Therefore, by driving the hydraulic cylinders 51, 52, the movable plate 4 moves to the side bars 21,
It is configured to be guided by the rolling of the rollers 41 on the 21 and move in the horizontal direction. Further, below the support 2, a filtrate tray 9 for receiving the filtrate 17 falling from the filter medium 1 at the time of filtering and pressing is provided movably and rotatably by driving the tray opening / closing cylinder 92.

The filtrate 17 is guided by the trough 91 and discharged to the outside.

Further, the cake 16 which has been filtered and squeezed is recovered by the screw conveyor 18 due to a natural drop due to the movement of the movable plate 4 and a downward drop due to the forced drop due to the vibration of the vibrators 12, 12. Has been done.

As shown in FIG. 1, the hydraulic pump 50a
Is connected so as to suck up the oil stored in the oil tank 70 and supply it to the hydraulic pressure switching valve 57.

A pressure control valve 55 and a pressure relief valve 56 are connected between the hydraulic pump 50a and the hydraulic pressure switching valve 57. The pressure control valve 55 is configured to control the pressure by a pressure control signal instructed by the control unit 100.

The oil supplied to the hydraulic pressure switching valve 57 passes through the hydraulic valve unit 58 having the hydraulic valve 58a for the first hydraulic cylinder and the hydraulic valve 58b for the second hydraulic cylinder, and then to the first hydraulic cylinder 51 and the first hydraulic cylinder 51. 2 hydraulic cylinder 52
And is configured to perform press filtration according to a required operation pattern. That is, when the hydraulic pump 50a is driven, the oil supplied to the hydraulic pressure switching valve 57 is pressure-controlled to a predetermined pressure which is predetermined by the pressure control valve 55 and the pressure relief valve 56, while the oil is supplied from the hydraulic pressure switching valve 57 to the first pressure. The hydraulic plate 58 is supplied to both the hydraulic valve 58a for the first hydraulic cylinder and the hydraulic valve 58b for the second hydraulic cylinder, the first hydraulic cylinder 51 and the second hydraulic cylinder 52 are driven in synchronization, and the movable plate 4 extends in the horizontal direction. Can be moved. As a pre-process before squeeze filtration, the movable plate 4 is moved to a predetermined position by driving the hydraulic cylinders 51 and 52, and when the volume of the filter chamber 11 is determined by the gap between the movable plate 4 and the receiving plate 31, The hydraulic valve 58b for the second hydraulic cylinder is switched to temporarily stop the oil supply from the hydraulic pump 50a to the first hydraulic cylinder 51, while the hydraulic valve 58a for the first hydraulic cylinder is left unchanged from the hydraulic pump 50a to the second hydraulic pump 50a. By continuing to supply oil to the hydraulic cylinder 52, the hydraulic cylinder 52 on the lower side is driven a little larger than the hydraulic cylinder 51 on the upper side to lower the volume below the upper side of the filter chamber 11 as shown in FIG. By tilting the movable plate 4 so as to narrow the side volume, it is possible to determine a predetermined upper and lower volume of the filter chamber 11. This is because the control unit 100 controls the pressure control valve 5
5. Controlling the hydraulic pressure supplied to the first hydraulic cylinder 51 and the second hydraulic cylinder 52 by controlling the input currents to the hydraulic valve 58a for the first hydraulic cylinder 5 and the hydraulic valve 58b for the second hydraulic cylinder. Therefore, the squeeze filtration can be performed by controlling the squeeze pressure to a predetermined operation pattern. Here, the reason why the movable plate 4 is inclined to make the lower part of the filter chamber 11 narrower than the upper part in setting the filter chamber volume is as follows. That is, the solid content in the stock solution tends to settle more downward due to gravity. Therefore, in order to produce a cake with a more uniform water content in the upper and lower parts after the pressing process, the lower part is narrowed when setting the volume to reduce the sedimentation amount in the lower part, and the solid content after the pressing is the same. This is because the cake may have a uniform water content.

Various operation patterns are stored in advance in a memory connected to the control unit 100, and the control unit 100 applies pressure according to an operation pattern preselected by the operator from the operation patterns stored in the memory. By controlling the input current of the control valve 55, the drive of the first hydraulic cylinder 51 and the second hydraulic cylinder 52 is controlled to change the pressure of the movable plate 4 on the cake of the filter medium 1 to select the squeezing pressure. The press operation is controlled by controlling the predetermined operation pattern.

As described above, the second opening / closing cylinder 7, the first opening / closing cylinder 6, the tray opening / closing cylinder 92, the screw conveyor 18, the vibrators 12 and 12, the hydraulic pump 50.
a, hydraulic pressure switching valve 57, hydraulic valve 5 for first hydraulic cylinder
8a, the hydraulic valve 58b for the second hydraulic cylinder, the first hydraulic cylinder 51, the second hydraulic cylinder 52, etc.
00, the desired filtration and squeezing process is automatically performed.

Next, a filtering method by the filtering device according to the above embodiment of the present invention will be described.

(Pre-Process) First, the support cord of the tubular filter medium 1 is suspended and supported by the vibrators 12 and 12 and the spring.

When the hydraulic cylinders 51 and 52 are driven to move the movable plate 4 to a predetermined position, and the volume of the filter chamber 11 of the tubular filter medium 1 is determined by the gap between the movable plate 4 and the receiving plate 31. , The hydraulic cylinder 52 on the lower side is driven slightly larger than the hydraulic cylinder 51 on the upper side, and as shown in FIG.
The movable plate 4 is inclined so that the volume on the lower side of the filter medium 1 is narrower than the volume on the upper side, and the predetermined upper and lower volumes of the filter chamber 11 of the tubular filter medium 1 are determined.

(Lower Closing Step) Next, the lower clamping bar 61 is moved by driving the first opening / closing cylinder 6 to close the lower end opening of the filter medium 1 as shown in FIG.

(Raw Material Feeding Step) Next, the stock solution 15 is fed into the filter medium 1 with the lower end closed by the stock solution inlet 8 shown in FIG.

As shown in FIG. 10, since the lower part of the filter chamber 11 narrows the filter chamber 11, the thickness of the filter chamber 11 is smaller than that of the upper part, but the solids in the stock solution 15 settle more in the lower part due to gravity.

(Upper tightening step) Next, as shown in FIG. 11, the upper tightening bar 71 is driven by driving the second opening / closing cylinder 7.
Is moved to close the upper part of the filter medium 1.

(Squeeze filtration step) Next, as shown in FIG. 12, the movable plate 4 is moved by driving the hydraulic cylinders 51 and 52, and the filter medium 1 is moved between the movable plate 4 and the receiving plate 31 as follows. The cake in the filter medium 1 is squeezed by pressing in the operation pattern as described in detail.

Here, when the cake in the filter medium 1 is squeezed, as shown in FIG. 3, first, in step S1, the control unit 100 selects from among various operation patterns stored in the memory, as shown in FIG. Data of operation pattern 1 as shown in, for example, displacement data A (P1, T1),
B (P2, T2), C (P3, T3), D (P4, T
4), E (P5, T5) is read.

Then, in step S2, the control unit 1
The calculation unit of 00 calculates and obtains the transformation amount per hour as follows.

[0038]

## EQU1 ## (P1-0) / (T1-0) = ΔPt1 (0
From point A)

[0039]

(2) (P2-P1) / (T2-T1) = ΔPt2
(Between points A and B)

[0040]

(P3) (P3−P2) / (T3−T2) = ΔPt3
(B point to C point)

[0041]

## EQU00004 ## (P4-P3) / (T4-T3) =. DELTA.Pt4
(Between points C and D)

[0042]

## EQU00005 ## (P5-P4) / (T5-T4) =. DELTA.Pt5
(Between points D and E) Next, in step S3, when the pressing step starts, the pressing timer TT starts.

Next, in step S4, the rotation of the hydraulic pump 50a starts.

Next, in steps S5 to S7, the control unit 100 sends a control signal corresponding to the pressure ΔPt1 × TT until the compression time TT reaches T1.
To control the squeeze pressure, and the squeeze pressure is displaced from 0 to point A.

Next, in steps S8 and S9, ΔPt2 × (TT-T) is reached from the pressing time T1 to T2.
A control signal corresponding to the pressure of 1) is input from the control unit 100 to the pressure control valve 55 to control the squeeze pressure, and the squeeze pressure is displaced from point A to point B.

In the same manner, steps S10 to S11 are performed.
In, the pressing time T4 to T5 via points C and D
Control signal corresponding to the pressure of ΔPt5 × (TT−T4) is input from the control unit 100 to the pressure control valve 55 to control the squeeze pressure, and the squeeze pressure is displaced from point D to point E to a predetermined value. The operation step 1 ends the pressing step.

The movable plate 4 at the end of the pressing process
The slope of the cake has disappeared, and the cake thickness at the top and bottom is almost uniform. Here, as an example of a method of eliminating the inclination of the movable plate 4, there is a method of previously setting the volume by examining how much the inclination should be eliminated after the squeezing is completed. This volume setting can be performed by detecting the operating distance of the hydraulic cylinder with a displacement sensor provided on the hydraulic cylinder, and the displacement of the movable plate can be eliminated by detecting the operating distance of the hydraulic cylinder with the displacement sensor. You can

(Cake discharging step) Next, after the squeezing step is completed, the hydraulic cylinders 51 and 52 are reversely driven to release the squeezing of the filter medium 1 by the movable plate 4.

Next, the first and second opening / closing cylinders 6 and 7 are reversely driven to open the openings at the upper and lower ends of the filter medium 1 to open the filter medium 1.
The cake 16 inside falls below the filter medium 1 due to the weight of the cake 16 falling below the filter medium 1 and the vibrations of the vibrators 12 and 12 and springs. Falling cake 16
Are collected by the cake collecting device of the screw conveyor 18 as shown in FIG.

The filtrate 17 filtered in the filtering and pressing step is recovered by the filtrate receiving tray 9 through the trough 91.

As the above-mentioned operation pattern, it is preferable to store various operation patterns according to the type of stock solution so that the operation pattern can be selected according to the type of stock solution.

According to the above embodiment, when the filter medium 1 is pressed by the movable plate 4, the hydraulic pump 50a drives the movable plate 4 toward the upper drive hydraulic cylinder 51 side and the movable plate 4 below the lower drive hydraulic cylinder. The movable plate 4 is used to press the filter medium 1 by using the hydraulic pressure transmitted to the 52 side, and the hydraulic pump 50a drives the movable plate 4 to the upper drive hydraulic cylinder 51 side and the movable plate 4 to the lower side. The input current input to the pressure control valve 55 that controls the hydraulic pressure transmitted to the hydraulic cylinder 52 side is calculated based on the operation pattern indicating the relationship between the squeezing time and the squeezing pressure. It is possible to change the pressure of the squeezing pressure based on the operation pattern according to the lapse of the squeezing time by controlling the squeeze pressure according to the above. Therefore, the squeezing pressure in the squeezing step can be current-controlled according to the passage of time, so that the squeezing pressure can be easily changed. Further, conventionally, since the squeezing pressure increasing step and the squeezing pressure maintaining step were repeated a considerable number of times, the electromagnetic valve was damaged quickly.However, in the above-described embodiment, switching of the electromagnetic valve of the electromagnetic switching valve is not possible during the squeezing step. Since the squeezing pressure is controlled by the current control of the pressure control valve without performing it, damage to the solenoid valve can be prevented, and maintenance and management of the solenoid valve becomes easier.
That is, conventionally, the squeezing pressure increasing step and the squeezing pressure holding step are repeated stepwise by switching the electromagnetic valve of the electromagnetic directional control valve during the squeezing step. On the other hand, in the present embodiment, during the squeezing process, the squeeze pressure is controlled by the current control of the pressure control valve without operating the solenoid valve of the solenoid directional control valve. It can be prevented.

If various operation patterns can be selected according to the type of stock solution and the operation pattern is selected according to the type of stock solution, more accurate squeeze filtration according to the type of stock solution can be performed. it can.

If the movable plate 4 is tilted so that the lower part of the filter chamber 11 is narrower than the upper part in the volume setting of the filter chamber in the previous step, after the press filtration, the upper part and the lower part of the filter chamber 11 become more A cake with a uniform water content can be produced.

The present invention is not limited to the above embodiment, but can be implemented in various other modes.

For example, FIG. 14 shows an operation pattern different from that of FIG. 2 among various operation patterns stored in the memory as an operation pattern in the filtration method of another embodiment of the present invention. In FIG. 14, the increase rate of the squeezing pressure at the beginning is made small, and the increase of the squeezing pressure is made larger in the latter half.

In this case, a smaller pressure is applied to the filter medium 1 in the initial stage of the squeezing process, and the damage to the filter medium 1 can be further reduced, and a rapid increase in the filtrate 17 in the initial stage of the squeezing process can be suppressed.

The filter medium 1 is not limited to the cylindrical filter medium, and may be a bag-shaped filter medium.

The first and second opening / closing cylinders may be air cylinders or hydraulic cylinders, and the same operation can be performed by other known drive devices.

Further, although the hydraulic cylinder and the movable plate are arranged on both sides of the filter medium and the movable plate is pulled toward the hydraulic cylinder to perform the squeeze filtration, the hydraulic cylinder and the movable plate are attached to the filter medium. It is also possible to arrange in the same direction and perform squeeze filtration by pushing the movable plate. Further, the pressing action of the pressing cylinder on the filter medium is not limited to pressing from one direction, and the filter medium may be pressed from two directions.

By properly combining the arbitrary embodiments of the aforementioned various embodiments, the effects possessed by them can be produced.

[0062]

According to the filtering method and the filtering device of the present invention, when the filter medium is pressed by the movable plate, the hydraulic pump drives the upper part of the movable plate and the lower part of the movable plate has hydraulic pressure. The hydraulic pressure transmitted to the cylinder side is used to press the filter medium by the movable plate, and is transmitted from the hydraulic pump to the upper drive hydraulic cylinder side of the movable plate and the lower drive hydraulic cylinder side of the movable plate. The input current input to the pressure control valve for controlling the hydraulic pressure is controlled according to the amount of transformation per hour calculated from the operation pattern indicating the relationship between the squeezing time and the squeezing pressure and the elapse of the squeezing time. Thus, the squeezing pressure based on the operation pattern can be changed with the passage of the squeezing time. Therefore, the squeezing pressure in the squeezing step can be current-controlled according to the passage of time, so that the squeezing pressure can be easily changed. Further, conventionally, since the squeezing pressure increasing step and the squeezing pressure maintaining step were repeated a considerable number of times, the electromagnetic valve was damaged quickly.However, in the above-described embodiment, switching of the electromagnetic valve of the electromagnetic switching valve is not possible during the squeezing step. Since the squeezing pressure is controlled by the current control of the pressure control valve without performing it, damage to the solenoid valve can be prevented, and maintenance and management of the solenoid valve becomes easier.

If various operation patterns can be selected according to the type of stock solution and the operation pattern is selected according to the type of stock solution, more accurate squeeze filtration according to the type of stock solution can be performed. it can.

Further, in setting the volume of the filter chamber in the previous step, if the movable plate is tilted so that the lower part of the filter chamber is narrower than the upper part, more uniform water content is obtained in the upper and lower parts of the filter chamber after squeeze filtration. Rate cakes can be produced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a filtration device that implements a filtration method according to an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the pressing pressure and the time during the pressing step of the undiluted solution according to the above embodiment.

FIG. 3 is a flowchart of a squeezing step of the filtration method according to the above embodiment.

FIG. 4 is a flowchart of a squeezing process according to the above embodiment, which is subsequent to FIG.

FIG. 5 is a front view of the filtration device according to the embodiment of the present invention.

FIG. 6 is a plan view of the filtration device.

FIG. 7 is a right side view of the filtration device.

FIG. 8 is a side view showing a pre-process in an operating state by the filtering device.

FIG. 9 is a side view showing a lower cut-off step in an operating state by the filtering device.

FIG. 10 is a side view showing a raw material charging step in an operating state by the filtering device.

FIG. 11 is a side view showing an upper tightening step in an operating state by the filtering device.

FIG. 12 is a side view showing a squeezing step in an operating state by the filtering device.

FIG. 13 is a side view showing a cake discharging step in an operating state by the filtering device.

FIG. 14 is a graph showing a relationship between pressing pressure and time according to another embodiment of the present invention.

[Explanation of symbols]

1 ... Filter material, 2 ... Support body, 3 ... Fixed plate, 4 ... Movable plate, 5 ...
Drive device, 6 ... First opening / closing cylinder, 7 ... Second opening / closing cylinder, 8 ... Stock solution inlet, 9 ... Filtrate tray, 10 ... Filtration device,
11 ... Filter chamber, 12 ... Vibration machine, 16 ... Cake, 17 ... Filtrate, 18 ... Screw conveyor, 21 ... Side bar, 3
1 ... Receiving plate, 32, 33 ... Locking part, 41 ... Roller, 50 ...
Hydraulic unit, 50a ... hydraulic pump, 51 ... first hydraulic cylinder, 52 ... second hydraulic cylinder, 55 ... pressure control valve,
56 ... Pressure relief valve, 57 ... Hydraulic switching valve, 58 ... Hydraulic valve unit, 58a ... First hydraulic cylinder hydraulic valve, 58b ... Second hydraulic cylinder hydraulic valve, 61 ... Lower tightening bar, 71 ... Upper tightening Bar, 91 ... Train, 92 ...
Saucepan opening / closing cylinder, 100 ... Control unit.

Claims (6)

[Claims] 1. A cylindrical filter medium (1) having a lower part closed and containing an undiluted solution to be filtered and then an upper part closed, a support (2) for supporting the filter medium, and a support for the support. A movable plate (4) for pressing the filter medium in a state where the lower portion and the upper portion of the filter medium are closed, and the filter medium in a state in which the lower portion and the upper portion of the filter medium supported by the support are closed. A receiving plate (31) which is sandwiched between the pressing plate and pressed to press and filter, a first opening / closing device (6) capable of closing the lower portion of the filter medium supported by the support, and the support. A filter device comprising a second opening / closing device (7) capable of closing the upper part of the supported filter medium, and two upper and lower hydraulic cylinders (51, 52) for driving the movable plate, comprising: a hydraulic pump (50a); Switching control of the driving force from the hydraulic pump (50a) The upper switching device (58a) selectively transmitting to the upper hydraulic cylinder (51) and the driving force from the hydraulic pump (50a) is switched to selectively control the lower hydraulic cylinder (52). And a pressure control valve for controlling the hydraulic pressure transmitted from the hydraulic pump (50a) to the upper hydraulic cylinder (51) side and the lower hydraulic cylinder (52) side. (55) and the input current input to the pressure control valve (55) according to the amount of transformation per hour calculated from the operation pattern indicating the relationship between the pressing time and the pressing pressure and the elapse of the pressing time. A filtering device comprising: a control unit (100) that controls the squeeze pressure based on the operation pattern so as to change the pressure according to the lapse of the squeeze time. 2. In setting the filter chamber volume of the filter medium before squeezing filtration, the movable plate is tilted so that the lower part is narrower than the upper part of the filter chamber to perform squeeze filtration. The filtration device according to claim 1, wherein the upper portion and the lower portion have the same volume to produce a cake having a uniform water content. 3. The filtering device according to claim 1, wherein the control unit is configured to make an increasing rate of the pressing pressure in the first half of the pressing step smaller than an increasing rate of the pressing pressure in the latter half of the pressing step. 4. A cylindrical filter medium (1) supported by a support (2) is closed at its lower part, a stock solution to be filtered is contained in the filter medium (1), and an upper part of the filter medium (1) is In a filtration method in which the filter medium is sandwiched between a receiving plate (31) that is closed and supported by the support and the movable plate (4), and the filter medium is pressed and squeezed and filtered, the filter medium is the movable plate. When pressing by the hydraulic plate (50a), the hydraulic pressure transmitted from the hydraulic pump (50a) to the upper drive hydraulic cylinder (51) side of the movable plate and to the lower drive hydraulic cylinder (52) side of the movable plate is used. While pressing the filter medium with the hydraulic pump (5
0a) to a hydraulic cylinder (5
1) side and the hydraulic cylinder (5) for driving the lower part of the movable plate
2) Pressure control valve (5) for controlling the hydraulic pressure transmitted to the side
The input current input to 5) is controlled according to the amount of transformation per hour calculated from the operation pattern indicating the relationship between the squeezing time and the squeezing pressure and the lapse of the squeezing time, and the lapse of the squeezing time A filtration method characterized in that the squeezing pressure based on the above operation pattern is changed accordingly. 5. In setting the filter chamber volume of the filter medium before squeezing filtration, the movable plate is tilted so that the lower part is narrower than the upper part of the filter chamber to perform squeeze filtration. The filtration method according to claim 4, wherein the upper portion and the lower portion have the same volume to produce a cake having a uniform water content. 6. The filtration method according to claim 4, wherein the control unit makes the rate of increase in the pressing pressure in the first half of the pressing step smaller than the rate of increase in the pressing pressure in the latter half of the pressing step.