JP3459640B2 - Screw press type 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 screw press type filtration device for filtering a processed product, and more particularly to a screw press type filtration device for controlling the end of a filtration process.

[0002]

2. Description of the Related Art Conventionally, sludge or other treated matter having a high water content is supplied from a supply port to a cylindrical filter body, and a screw provided inside the cylindrical filter body discharges the treated matter from the outlet. A screw press type filtration device is used for filtering the processed material by the filtration body while being transported to the above. In this screw press type filtration device, the filter body is washed as necessary after the filtration step for filtering the processed material is completed. When this cleaning is performed, the outlet is closed manually by the operator after the filtration process. Then, the worker operates the cleaning device to spray the cleaning water from the outside to the inside of the filter body to clean the inside of the filter body.

[0003]

However, in the above-described screw press type filtering device in the prior art, the operator manually closes the discharge port. Therefore, the discharge port cannot be closed due to an operator error or the like. There was a possibility that the filter body would be washed. As a result, there is a problem in that the cleaning water that has entered the filter body is mixed with the filtered product. Further, if the cleaning is carried out in a state where the treated product remains in the filter body, there is a problem that it takes a long time to complete the cleaning.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent the washing water from being mixed in the treated product after the filtration, and to shorten the time for washing the filter body. The object is to provide a screw press type filtration device that can be used.

[0005]

In order to achieve the above object, the present invention provides a screw, which is rotatably inserted inside a generally cylindrical filter body, and which is provided between one end of the screw and the filter body. The object to be treated, which has been supplied to, is conveyed to the other end side by the rotation of the screw and is provided at the outlet.
The back-pressure valve is filtered by the filter medium while applying a back pressure to the treated product, a screw press type filtration apparatus for discharging from the discharge port provided on the other end, the filter
In the case of ending the filtration process,
Before washing, the back pressure should be greater than the back pressure in the filtration process.
Pressure control for controlling the back pressure of the back pressure valve so that the pressure becomes equal to
Means and the back pressure valve control means,
Control of the back pressure valve so that the back pressure is greater than the back pressure
Control means for shifting to the cleaning step after the control is performed .

Further, in the above-mentioned screw press type filtration device according to the present invention, the back pressure valve control means comprises:
After making the pressure lower than the back pressure in the stroke,
To have a back pressure greater than the back pressure in the filtration process
The back pressure of the back pressure valve is controlled . Also,
The present invention is the above-mentioned screw press type filtration device, wherein the back pressure valve control means controls the back pressure greater than the back pressure in the filtration stroke after the processed material in the filtration body is discharged.
The back pressure of the back pressure valve is controlled so that the pressure becomes a pressure .

Further, the present invention is characterized in that, in the above-mentioned screw press type filtration device, the back pressure valve control means has an instruction means for instructing the end of the filtration stroke. Further, the present invention is, in the above-mentioned screw press type filtration device, a drive means for rotating the screw,
Drive control means for controlling the drive means such that the rotation speed of the screw reaches a preset rotation speed when the filtration step is finished.

Further, according to the present invention, a screw is rotatably inserted inside a generally cylindrical filter body, and a processed material supplied from one end side of the screw to the filter body is
Ejection while conveying to the other end by rotation of the screw
Back pressure is applied to the processed material by the back pressure valve installed in the mouth
While cleaning with a screw press type filtering device that filters with the filter body and discharges from the discharge port provided on the other end side, when the filtration step for performing the filtration is completed.
Before cleaning the filter body,
Of the back pressure valve so that the back pressure is greater than the back pressure at
Control back pressure and move to the washing step to wash the filter body.
Characterized in that that.

Further, according to the present invention, a screw is rotatably inserted inside a generally cylindrical filter body, and a processed material supplied from one end side of the screw to the filter body is
Ejection while conveying to the other end by rotation of the screw
Back pressure is applied to the processed material by the back pressure valve installed in the mouth
While being a computer-readable recording medium in which a control program of a screw press type filtering device which is filtered by the filtering body and discharged from the discharge port provided on the other end side is recorded, the filtering process for performing the filtering is completed. Place
Before cleaning the filter body,
Of the back pressure valve so that the back pressure is greater than the back pressure at
Controlling the back pressure and the back pressure in the filtration process
The back pressure valve is controlled so that the back pressure becomes larger than
After that, a control program for causing a computer to execute the step of shifting to the cleaning process is recorded.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A screw press type filtration device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing the configuration of a screw press type filtration device according to an embodiment of the present invention. In the figure, the screw 4 has a screw blade 4B formed in a spiral shape on the outer periphery of a screw shaft 4A around an axis O, and is rotatably supported by bearings 5 and 5.
A drive unit 50 for rotating the screw 4 is connected to the end of the screw shaft 4A supported by the bearing 5 on the other end side of the screw 4.

The screw 4 is rotationally driven around the axis O by the drive unit 50 being connected to the screw shaft 4A, and conveys the processed material supplied from one end side to the other end side. The drive unit 50 is, for example, a motor, and rotates the screw so that the rotation speed n is instructed by the drive control unit 42 of the control unit 40.

While the screw blade 4B of the screw 4 has a constant helix angle and outer diameter, the outer periphery of the screw shaft 4A is constant in the range from the one end to the position R in the portion where the screw blade 4B is provided. The diameter is the outer diameter, and the diameter gradually increases in the direction from the position R toward the other end of the filter body 10. As a result, the space between the outer periphery of the screw shaft 4A and the screw blades 4B adjacent to each other in the direction of the axis O is smaller on the other end side than on the one end side. In addition, instead of changing the outer diameter of the screw shaft 4A so as to increase on the other end side as described above, the screw shaft 4A is changed.
The space may be reduced by reducing the pitch of the screw blades 4B toward the other end while keeping the outer diameter constant. Alternatively, in combination with these, the space may be reduced on the other end side by increasing the outer diameter of the screw shaft 4A on the other end side and decreasing the pitch of the screw blades 4B.

The filter body 10 has a substantially cylindrical shape,
The screw 4 described above is inserted into the inner circumference of the filter body 10. As a result, while the processed material is conveyed from the one end side to the other end side by the screw 4, the filter body 10
It is dehydrated and filtered by. In addition, this filter body 10
A supply unit 13 that supplies the processed product from the coagulation and mixing tank 64 is provided on one end side of the. The discharge port 9 is provided on the other end side of the filter body 10 and discharges the filtered processed product as a cake.

The agitator 63 is rotationally driven based on an instruction from the control unit 40, and agitates the sludge treatment chemicals and sludge supplied to the coagulation mixing tank 64 by the chemical injection pump 61 and the sludge supply pump 60. . The sludge supply pump 60 is
It is driven based on an instruction from the control unit 40, and the processed product is supplied to the aggregating and mixing tank 64. This treated product may be a variety other than sludge. The chemical injection pump 61 is driven based on an instruction from the control unit 40, and supplies various chemicals to be added to the processed material to the coagulation / mixing tank 64. The processed material accumulated in the coagulation-mixing tank 64 is supplied into the filter body 10 via the supply unit 13 when the valve 65 is opened in response to an instruction from the control unit 40.

The input unit 62 instructs the control unit 40 to end the filtration process based on the instruction input by the operator.
When the end of the filtration process is instructed from the input unit 62, the control unit 40 performs stop control of the screw press type filtration device (details will be described later). The control unit 40 also includes a back pressure valve control unit 41 and a drive control unit 42.

The back pressure valve control unit 41 stores back pressure p1 and back pressure p2 which are preset values. The back pressure p1 is set as a discharge pressure when discharging the processed material remaining in the filter body 10. The back pressure mentioned here is the pressure received by the processed material in the filter body 10.
For example, the back pressure p1 is set to a back pressure (low back pressure) for fully opening the back pressure valve 21, and the back pressure p2 is a back pressure (high back pressure) for closing the back pressure valve 21. Is set. Further, the back pressure valve control unit 41 reduces the pressure at which the back pressure valve 21 suppresses the processed material to the back pressure p1 based on the instruction from the control unit 40 to end the filtration process, and the processed material in the filter body 10 is discharged. After that, the cylinder controller 24 is controlled so that the pressure of the back pressure valve 21 becomes the back pressure p2. Cylinder control unit 24
Controls the pressure generated by the air cylinder 22 based on a control signal from the back pressure valve control unit 41 of the control unit 40.

The back pressure valve 21 is provided at the discharge port 9 and suppresses discharge of the processed material discharged from the discharge port 9. Further, the air cylinder 2 is provided on the other end side (drive unit 50) of the back pressure valve 21.
Two piston rods 22A are connected to each other, and the piston rods 22A project and retract toward the one end side in parallel to the axis O to move the back pressure valve 21 back and forth, so that the distance between the back pressure valve 21 and the end portion 8 is increased. By appropriately setting, it becomes possible to adjust the discharge amount of the cake from the discharge port 9. Here, the pressure applied by the back pressure valve 21 to the processed material in the filter body 10 is referred to as the pressure of the back pressure valve.

The air cylinder 22 has a piston rod 22.
By A, the back pressure valve 21 is caused to generate a pressure (pressure of the back pressure valve) for suppressing discharge of the processed material. This air cylinder 22
Is used as a pressurizing means for generating pressure in the back pressure valve 21, the pressure in the filter body 10 can be easily controlled.

The drive control unit 42 controls the number of rotations of the screw 4 rotated by the drive unit 50 based on an instruction from the control unit 40. Further, the drive control unit 42, based on an instruction from the control unit 40, when the filtration process is completed, the rotation speed of the screw 4 is set to a preset rotation speed n1.
The drive 50 is controlled so that This rotation speed n1 is
For example, it is set to the maximum rotation speed determined as the rated value of the drive unit 50.

Next, the operation of the screw press type filtration device having the configuration of FIG. 1 will be described with reference to the drawings. FIG. 2 is a flow chart for explaining the operation of the screw press type filtration device in this embodiment. First, according to the operation instruction from the worker, the control unit 40
Starts the operation of the screw press type filtration device, supplies chemicals to the aggregating and mixing tank 64 by the chemical injection pump 61, and controls supplying sludge to the aggregating and mixing tank 64 by the sludge supply pump 60. Then, the control unit 40
Drives the stirrer 63 to stir the chemicals and the processed material in the coagulation and mixing tank 64. Then, after the drive time of the stirrer 63 has passed a predetermined time, the valve 65 is controlled to open. As a result, a processed product (hereinafter simply referred to as “processed product”) in which the chemicals are mixed is supplied from the coagulation / mixing tank 64 into the filter body 10 via the supply unit 13.

Next, when the rotation of the drive unit 50 is transmitted to the screw shaft 4A and the processed product is sequentially supplied from the supply unit 13, the processed product is filtered and the screw blades 4 are inserted.
B and the space that is formed by the screw shaft 4A, and while being conveyed from one end side of the filter body 10 to the other end side by the rotation of the screw 4, it is gradually dehydrated and filtered due to the volume reduction of the space described above. (Step S
1).

When the operator inputs an instruction to end the filtration process from the input unit 62 after the filtration process is performed (step S2), the control unit 40 starts the stop control,
The sludge supply pump 60, the chemical injection pump 61, and the agitator 63 of the coagulation-mixing tank 64 are stopped (step S3). Next, the control unit 40 drives the drive control unit 42 so that the rotation speed of the screw 4 becomes n1 after a preset fixed time for switching the rotation speed of the screw 4 has passed (step S4). The unit 50 is controlled (step S5). The drive unit 50 responds to an instruction from the drive control unit 42 of the control unit 40 so that the current rotation speed n of the screw 4 is n.
It is rotated so that it becomes 1.

Furthermore, the control unit 40 causes the back pressure valve control unit 41 to set the back pressure to p1 when the preset fixed time for closing the back pressure valve 21 has passed (step S6). Control (step S
6). The cylinder control unit 24 controls the air cylinder 22 so that the back pressure becomes p1 based on the instruction from the back pressure valve control unit 41. As a result, the pressure of the back pressure valve provided from the back pressure valve 21 is reduced to the back pressure p1 and the opening degree of the back pressure valve 21 increases. Then, after the supply of the processed product from the supply unit 13 is stopped, the processed product remaining in the filter body 10 is discharged from the discharge port 9. Here, the back pressure p is p1
Since the number of rotations n of the screw 4 is n1, the back pressure is reduced, the number of rotations is increased, and the time required for discharging the processed material is shortened.

Then, the control unit 40 causes the back pressure valve control unit 41 to control the back pressure when a preset constant time corresponding to the time for discharging the processed material remaining in the filter body 10 elapses (step S8). The cylinder controller 24 is controlled so that becomes p2 (step S9). Cylinder control unit 2
4 controls the air cylinder 22 based on an instruction from the back pressure valve control unit 41 so that the back pressure becomes p2. As a result, the back pressure valve 21 comes into contact with the end portion 8 of the filter body 10 and the back pressure valve 21 is fully closed (step S10).

After the back pressure valve 21 is fully closed, the process proceeds to the washing step (step S11), and when the washing of the filter body 10 is completed, the control section 40 controls so as to stop each section of the apparatus. (Step S12).

According to the embodiment described above, the back pressure valve 2
Since 1 is fully closed and the process proceeds to the cleaning step, it is possible to prevent the cleaning water sprayed from the outside to the inside of the filter body 10 from being mixed from the inside of the filter body 10 into the processed product that has been filtered. You can

In the embodiment described above, the case where the air cylinder 22 is applied when the back pressure valve 21 is moved back and forth has been described, but the back pressure valve 21 may be moved back and forth using a device other than the air cylinder 22. Good.

In the above embodiment, the back pressure p2
Has described the case where the pressure for fully opening the back pressure valve 21 is set, the present back pressure valve 21 and the filter body 10 are described.
And a value that makes the opening larger. In step S6 of FIG. 2, when the back pressure valve 21 is opened, the back pressure valve control unit 41 may control the cylinder control unit 24 to gradually open the back pressure valve 21.

In the above-described embodiment, the case where the drive control unit 42 controls the rotation speed of the screw 4 to be the rotation speed n1 during the stop control has been described. If the control is to speed up, it is not always necessary to increase the rotation speed of the screw 4 to the rated value of the drive unit 50. Further, during the stop control, the control for increasing the rotation speed of the screw 4 does not necessarily have to be performed.

Further, by recording a program for realizing the function of the control section 40 in FIG. 1 in a computer-readable recording medium, and reading the program recorded in this recording medium into a computer system and executing it. The stop control of the screw press type filtering device may be performed. In addition, "computer system" here
The term “OS” includes hardware such as OS and peripheral devices.

The "computer-readable recording medium" means a floppy disk, a magneto-optical disk, an R
It refers to a portable medium such as OM and CD-ROM, and a storage device such as a hard disk built in a computer system.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific structure is not limited to this embodiment, and includes a design etc. within the scope not departing from the gist of the present invention. Be done.

[0033]

As described above, according to the present invention, since the back pressure valve is closed after the filtering process is completed, the cleaning water for cleaning the inside of the filter body flows out from the discharge port, It is possible to prevent contamination of the discharged cake. Further, according to the present invention, at the end of the filtration process, the back pressure valve is controlled to be closed after the pressure for suppressing the processed material is reduced, so that the processed material remaining in the filter body is treated. Since the discharge time can be shortened, the time required for the stop control can be shortened.

Further, according to the present invention, since the instructing means for instructing the end of the filtering process is provided and the filtering process of the screw press type filtering device is completed in accordance with the instruction from the instructing device, it is possible for the worker to do so. The operation of stopping the filtration process of the screw press type filtration device can be simplified, and the effect of reducing operation mistakes can be obtained. Further, according to the present invention, when the filtration process is finished, the rotation speed of the screw is set to a preset rotation speed, so that it is possible to shorten the time for discharging the processed material remaining in the filtration body. It is possible. Further, according to the present invention, since the filter body is washed after discharging the processed material remaining in the filter body, the amount of the processed material remaining in the filter body can be reduced, and the filter body is cleaned. The effect of being able to shorten the time to do is obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of a screw press type filtration device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the screw press type filtration device having the configuration of FIG.

[Explanation of symbols]

4 Screw 9 Discharge Port 10 Filter 13 Supply Unit 21 Back Pressure Valve 24 Cylinder Control Unit 40 Control Unit 41 Back Pressure Valve Control Unit 42 Drive Control Unit 50 Drive Unit 60 Sludge Supply Pump 61 Chemical Injection Pump 63 Stirrer 64 Coagulation Mixing Tank

Front page continuation (56) References JP 2001-38490 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B01D 29/25 B01D 29/60

Claims (7)

(57) [Claims] 1. A screw is rotatably inserted inside a generally cylindrical filter body, and a processed material supplied between one end side of the screw and the filter body is fed to the other end side by rotation of the screw. While being transported to the
A screw press type filtering device which filters the processed material by a back pressure valve while applying a back pressure to the processed material, and discharges from a discharge port provided on the other end side, in the case of ending the filtration process for performing the filtration. And said
Before washing the filter body, from the back pressure in the filtration process,
The back pressure that controls the back pressure of the back pressure valve so that the back pressure becomes large.
By means of a pressure valve control means and the back pressure valve control means,
The back pressure valve is controlled so that the back pressure is larger than the pressure.
And a control means for shifting to a cleaning step after being removed. 2. The back pressure valve control means is configured to perform the filtering process.
After setting the pressure to be lower than the back pressure in
The back pressure should be greater than the back pressure during the overstroke.
The screw press type filtration device according to claim 1, wherein the back pressure of the pressure valve is controlled . 3. The back pressure valve control means controls the back pressure in the filtration process after the processed material in the filtration body is discharged .
The screw press type filtration device according to claim 1 or 2 , wherein the back pressure of the back pressure valve is controlled so that the back pressure becomes even greater . 4. The screw press type filtration device according to claim 1, further comprising an instruction means for instructing the back pressure valve control means to end the filtration stroke. 5. A drive means for rotating the screw, and a drive control means for controlling the drive means such that the rotation speed of the screw becomes a preset rotation speed when the filtration stroke is finished. Of Claim 1 to Claim 4 characterized by having
The screw press type filtration device according to any one of claims. 6. A screw is rotatably inserted inside a substantially cylindrical filter body, and a processed material supplied between one end side of the screw and the filter body is fed to the other end side by rotation of the screw. While being transported to the
The back-pressure valve is filtered by the filter medium while applying a back pressure to the treated product, a method for cleaning a screw press type filtration apparatus for discharging from the discharge port provided on the other end, a filtration step of performing said filtering When ending,
Before washing the filter body, from the back pressure in the filtration process,
Control the back pressure of the back pressure valve so that
A method for cleaning a screw press type filtration device , comprising: moving to a cleaning step to clean the filter body . 7. A screw is rotatably inserted inside a generally cylindrical filter body, and a processed material supplied from one end side of the screw to the filter body is fed to the other end side by rotation of the screw. While being transported to the
A computer-readable recording medium in which a control program of a screw press type filtering device, which is filtered by the filter while applying a back pressure to the object to be processed by a back pressure valve and discharged from an outlet provided on the other end side, is recorded. In the case of ending the filtration step of performing the filtration,
Before washing the filter body, from the back pressure in the filtration process,
Control the back pressure of the back pressure valve so that the back pressure is also large.
The back pressure should be higher than the back pressure in the above-mentioned filtration process.
After the control of the back pressure valve is performed, a cleaning process is performed.
A recording medium recording a control program that causes a computer to execute the steps .