JP2002336610A - Rotary single chamber type filter and cleaning method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary single chamber type filter and a cleaning method thereof, in which the lowering of the throughput through the total operation time is prevented and an automatic operation is performed to save labor at the time of stopping a filtering process and performing a cleaning process by a cleaning means. SOLUTION: The liquid level in an original liquid slurry bat is controlled to a prescribed level by detecting the liquid level in the original slurry bat by a liquid level detector and adjusting the supply quantity of the original liquid slurry by an original liquid flow rate control valve arranged in an original liquid supply pipe, the original liquid flow rate is measure with an original liquid flow meter arranged in the original liquid supply pipe and when the measured value reaches equal to or below the prescribed value, the filtering process is stopped and the cleaning process by the cleaning means is started.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary single-chamber type filter for solid-liquid separation of an undiluted slurry containing solid matter (hereinafter sometimes simply referred to as "slurry") by a single-chamber filtration drum, and a rotary single-chamber filter. The present invention relates to a washing method in a filter.

[0002]

2. Description of the Related Art Conventionally, in the general chemical industry, fertilizer industry, metal industry, food industry, pulp industry, and the like, a large number of liquid passage holes are formed in a circumferential surface, and a filter cloth is stretched on the outer circumferential surface. A sealed single-chamber type filtration drum is mounted on a center pipe, and the lower part of the filtration drum is immersed in the stock slurry in the stock slurry vat, and the stock solution is suction-filtered while being stirred by the stirring means, and filtered into the filter drum. The filtrate obtained is discharged out of the apparatus by a filtrate pipe connected to the center pipe, and the cake layer formed on the outer peripheral surface of the filter cloth is connected to the center pipe and blown from a slit of a valve shoe which is in sliding contact with the inner peripheral surface of the filter drum. A rotary single-chamber type filter that separates and recovers by a pressure gas is used. In addition, the rotary single-chamber type filter has a high filtering capability due to a large opening ratio of a drum and a large diameter of a filtrate tube, and a high cleaning effect because a uniform flow of a cleaning solution can be maintained throughout the cake.
The filter fabric is blown back more efficiently by blowback air, so it has many advantages, such as easy removal of thin cakes with poor filtration properties, and its simple structure with less trouble and easy maintenance. Many are used from such things.

The configuration and operation of a conventional rotary single-chamber filter will be described with reference to the configuration diagram of the apparatus shown in FIG.
Reference numeral 1 denotes a sealed single-chamber type filter drum in which both end surfaces are sealed and a large number of liquid passage holes 2 are formed in a circumferential surface, and a filter cloth 3 is stretched on an outer circumferential surface thereof and penetrates an axis portion. And the lower part of the filtration drum 1 is immersed in the stock slurry in the stock slurry vat 4 and is rotatably suspended.
It is configured to be rotated by a rotation drive device such as a variable speed reducer (not shown). The center pipe 5 is composed of two tubes, and a lower portion of one of the tubes has a lower end immersed in the filtrate in the rotary drum and a filtrate tube 6 for sucking and discharging the filtrate filtered by the filter drum 1 out of the machine. Is connected to the other pipe via a valve bar 8 and a header pipe 11, and a valve shoe 7 made of synthetic resin, which is in sliding contact with the inner peripheral surface of the filtration drum 1, is connected to the other pipe in the axial direction of the center pipe 5. A plurality is arranged along.

The valve shoe 7 is divided into two parts in the circumferential direction of the filter drum 1, and blow gas supplied through a valve bar 8 connected to the center pipe 5 is supplied to a section on the rear side in the rotational direction of the filter drum 1. A first slit 9 for spraying from the back side of the cake layer to separate and collect the cake layer formed on the outer peripheral surface of the filter cloth is formed, and the section on the front side in the rotation direction is inserted through the center pipe 5. A second slit 10 is formed for spraying a cleaning liquid through a header pipe 11 connected to a cleaning pipe (not shown) to remove cake remaining on the filter cloth.

A stirring means 18 (hereinafter, referred to as an agitator) for stirring the slurry is provided inside the stock slurry vat 4, and a filter cloth 3 is provided above the outside of the filter drum 1.
A cake washing tube 12 for spraying a washing liquid onto a cake layer formed on the surface of the filter cloth, and a filter cloth washing tube 1 for spraying a washing liquid onto the surface of the filter cloth 3 after the cake peeling and collecting to wash the cake.
4 are arranged. The filtration drum 1 is covered by a casing 17 having a stock slurry vat 4 formed at the lower part. The filter drum 1 is located at the upper end of the stock slurry vat 4 and faces the valve shoe 7. A cake chute 13 for discharging the cake separated by the blow gas to the outside of the machine is provided with an opening. Fifteen
Is a reslurry tank for storing the stock slurry discharged during the washing process, etc., 16 is a stock slurry supply pump for supplying the slurry to the stock slurry vat 4, and 19 is a limit for detecting the liquid surface position in the stock slurry vat. It is a liquid level detector such as a switch.

Next, a description will be given of a filtration method of the conventional rotary single-chamber filter having the above-mentioned configuration. The undiluted slurry supply pump 16 supplies a constant flow rate of the slurry to the undiluted slurry vat 4, and the liquid level detector 19 detects the slurry level in the undiluted slurry vat 4,
The output of the stock slurry supply pump 16 is adjusted to control the amount of slurry supply. While stirring with the agitator 18 so that the solid content in the slurry does not settle, the filtration drum 1
Is rotated, and the inside of the filtration drum 1 is maintained at a vacuum by a vacuum device (not shown) outside the apparatus via the filtrate pipe 6, the center pipe 5, and a connecting pipe (not shown). Thereby, the slurry in the stock slurry vat 4 in contact with the filtration drum 1 is suction-filtered, and the filtrate passes through the liquid passage holes 2 and the filter cloth 3 and accumulates at the bottom of the filtration drum 1,
A cake layer is formed on the surface of the filter cloth 3.

[0007] The filtrate collected in the filtration drum 1 is sucked by a filtrate pipe 6 which is suctioned under reduced pressure, and discharged out of the apparatus via a center pipe 5. Further, the cake layer formed on the filter cloth 3 rises with the rotation of the rotary drum 1, and is washed at the cake washing position of the spray tube 12 with the washing liquid sprayed from the spray tube 12, and further rotated. The liquid is removed by the vacuum in the filtration drum 1 while descending. Further, the cake layer that has been drained is rotated by the rotation of the rotating drum 1 and the center pipe 5 is disposed at the position where the valve shoe 7 is disposed.
The cake is peeled off from the first slit 9 of the valve shoe 7 through the valve bar 8 by the blow gas injected to the back side of the cake layer, and the peeled cake is discharged out of the machine via the cake chute 13. Filter cloth 3 from which cake layer was removed
The surface is cleaned by the cleaning liquid sprayed from the filter cloth cleaning pipe 14, and the remaining cake adhered by the cleaning liquid sprayed from the second slit 10 of the valve shoe 7 to the back side through the header pipe 11 connected to the cleaning liquid pipe. The removed cake is dropped and returned into the stock slurry vat 4 with the washing liquid. By repeating the filtering operation, the filtering process is continuously performed.

[0008] With the progress of the above-mentioned filtration operation, clogging of the filter cloth gradually progresses, and the filtration ability decreases. Therefore, the filtration step is stopped, and the slurry in the stock slurry vat 4 is reslurried. After being discharged to the tank 15, a cleaning step is performed by the cleaning means. The cleaning step is mainly performed by injecting the cleaning liquid from the second slit 10 of the valve shoe 7 through the header pipe 11 and the cleaning liquid from the filter cloth cleaning pipe 14. The cleaning step is performed. The timing is performed manually by the judgment of the operator, or at a time interval set by a timer.

[0009]

In the above-mentioned conventional method of performing a cleaning step, the amount of manual processing is unstable and complicated due to human judgment by an operator. Regardless of this, the cleaning process is performed at predetermined time intervals, so that there is a problem that the throughput during the entire operation time is reduced.

[0010] The present invention has been made in view of the above-mentioned problems, and the filtering ability is reduced with the lapse of time of the filtering operation. The purpose of the present invention is to provide a rotary single-chamber filter that can be operated automatically and requires less time and a method for cleaning the same without causing a reduction in throughput during the entire operation time as much as possible during the cleaning process. It is.

[0011]

The gist of the present invention for achieving the above object is as follows.
A large number of liquid passage holes are formed in the circumferential surface, and a sealed single-chamber type filter drum with a filter cloth stretched on the outer peripheral surface thereof is mounted on a center pipe, and the lower part of the filter drum is located in the stock slurry vat. It is immersed in the stock solution slurry, suction-filtered while stirring the stock solution with stirring means, and the filtrate filtered in the filter drum is discharged outside the machine with a filtrate tube connected to the center pipe, and formed on the outer peripheral surface of the filter cloth. In a rotary single-chamber filter, the cake layer is connected to the center pipe, and separated and recovered by a pressure gas blown from a slit of a valve shoe that slides on the inner peripheral surface of the filtration drum. A liquid level detector for detecting a liquid level position; a raw liquid slurry flowmeter for measuring a raw liquid slurry flow rate to a raw liquid slurry supply pipe for supplying a raw liquid slurry to the raw liquid slurry vat; A rotary single-chamber filtration unit, characterized in that disposed between stock slurry flow rate control valve for controlling the stock slurry supply amount by the liquid level detector.

Further, in the invention according to claim 2,
A large number of liquid passage holes are formed in the circumferential surface, and a sealed single-chamber type filter drum with a filter cloth stretched on the outer peripheral surface thereof is mounted on a center pipe, and the lower part of the filter drum is located in the stock slurry vat. It is immersed in the undiluted solution slurry, suction-filtered while stirring the undiluted solution by the stirring means, and the filtrate filtered in the filter drum is discharged out of the machine with a filtrate tube connected to the center pipe, and formed on the outer peripheral surface of the filter cloth. In a rotary single-chamber filter, the cake layer is connected to the center pipe, and separated and recovered by a pressure gas blown from a slit of a valve shoe that slides on the inner peripheral surface of the filtration drum. The liquid level position is detected by a liquid level detector, and the raw liquid slurry supply amount is adjusted by the raw liquid slurry flow control valve provided in the raw liquid slurry supply pipe, and the The liquid level is controlled to a predetermined position, and the flow rate of the raw slurry is measured by a raw slurry flow meter provided in the raw slurry supply pipe. When the measured value falls below a predetermined value, the filtration step is stopped and the washing is performed. A washing method for a rotary single-chamber filter, wherein a washing step by means is performed.

[0013] With the above configuration, as the filtering performance decreases with the lapse of time of the filtering operation, and when the filtering capacity falls below a predetermined level, the filtering step is stopped and the cleaning step by the cleaning means is performed. A rotary single-chamber type filtering machine which can be reduced in number, and therefore can be operated automatically without reducing the throughput during the entire operation time as much as possible, so that it does not take much time and a method for cleaning the same.

Further, in the invention according to claim 3,
3. The method for cleaning a rotary single-chamber filter according to claim 2, wherein the filtration step is stopped when the flow rate of the stock slurry measured by the stock slurry flow meter drops to less than 95% of the steady operation. The cleaning method for a rotary single-chamber filter according to claim 2, wherein the cleaning step is performed by a cleaning means.

With the above configuration, even if the filtering step is stopped and the washing step is performed by the washing means when the filtering ability is reduced to a predetermined level or less with the lapse of time of the filtering operation, the operation is stopped. The number of times can be minimized, and thus the reduction in the throughput during the entire operation time can be minimized. In addition, the stock solution slurry flow rate was 95-9.
When the flow rate falls to 0%, it is preferable to stop the filtration step and perform the washing step. When the stock solution slurry flow rate is higher than 95% in the steady operation, the washing timing is too early. The throughput decreases during the entire operation time. On the other hand, when the flow rate is reduced to less than 90%, the reduction of the filtration capacity becomes too large.

[0016]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a rotary single-chamber filter according to an embodiment of the present invention. It should be noted that, in FIG.
The same reference numerals are given to members having the same action in the configuration diagram of the conventional rotary single-chamber type filter.

Reference numeral 1 denotes a sealed single-chamber type filter drum in which both end surfaces are sealed and a large number of liquid passage holes 2 are formed in a circumferential surface. A filter cloth 3 is stretched on the outer circumferential surface of the filter drum. The lower part of the filter drum 1 is immersed in the stock slurry in the stock slurry vat 4 so as to be rotatably mounted on a center pipe 5 penetrating therethrough, and is rotatably suspended by a rotary drive device such as a variable speed reducer (not shown). It is configured to be. The center pipe 5 is composed of two tubes, and a lower portion of one of the tubes has a lower end immersed in the filtrate in the rotary drum and a filtrate tube 6 for sucking and discharging the filtrate filtered by the filter drum 1 out of the machine. Is connected to the other pipe, and a valve shoe 7 made of a synthetic resin, which is in sliding contact with the inner peripheral surface of the filtration drum 1, is connected to a valve bar 8.
And the center pipe 5
Are arranged along the axial direction of the.

The valve shoe 7 is divided into two parts in the circumferential direction of the filter drum 1, and blow gas supplied through a valve bar 8 connected to the center pipe 5 is supplied to a section on the rear side in the rotational direction of the filter drum 1. A first slit 9 for spraying from the back side of the cake layer and separating and collecting the cake layer formed on the outer peripheral surface of the filter cloth is formed, and a section on the front side in the rotation direction is inserted through the center pipe 5. A second slit 10 is formed for spraying a cleaning liquid through a header pipe 11 connected to a cleaning pipe (not shown) to remove cake remaining on the filter cloth.

An agitator 18 as stirring means for stirring the undiluted slurry is provided in the undiluted slurry vat 4, and a washing liquid is applied to a cake layer formed on the surface of the filter cloth 3 above the outside of the filter drum 1. A cake washing tube 12 for spraying and washing, and a filter cloth washing tube 14 for ejecting and washing a washing liquid onto the surface of the filter fabric 3 after cake peeling and recovery are arranged below the outside. The filtration drum 1 is covered by a casing 17 having a stock slurry vat 4 formed at the lower part. The filter drum 1 is located at the upper end of the stock slurry vat 4 and faces the valve shoe 7. A cake chute 13 for discharging the cake separated by the blow gas to the outside of the machine is provided with an opening.

Reference numeral 15 denotes a reslurry tank for storing a stock slurry discharged during a washing step or the like, and reference numeral 16 denotes a stock slurry supply pump for feeding the stock slurry to the stock slurry vat 4. Further, reference numeral 19 denotes a liquid level detector for detecting the liquid level position in the raw liquid slurry vat, and reference numeral 20 denotes a raw liquid slurry supply pipe for supplying the raw liquid slurry to the raw liquid slurry vat 4. A stock slurry flow rate control valve for controlling the amount, 21
Reference numeral denotes a stock slurry flow meter for measuring the stock slurry flow rate provided in the stock slurry supply pipe.

Next, a description will be given of a filtering method of the rotary single-chamber filter according to the present invention having the above-described structure. The undiluted slurry supply pump 16 supplies a constant flow rate of the undiluted slurry to the undiluted slurry vat 4 from the undiluted solution supply pipe. The liquid level detector 1 detects the liquid level position of the raw slurry in the raw slurry vat 4.
The liquid surface in the stock slurry vat is maintained at a predetermined position by controlling the stock solution slurry flow rate control valve 20 provided in the stock solution supply pipe and controlling the stock solution slurry supply amount, while detecting at step 9. In addition, the filtration drum 1 is rotated by a rotation driving device (not shown) while stirring by the agitator 18 so that the solid content in the slurry does not settle, and the filtrate pipe 6, the center pipe 5 and the connection are connected by a vacuum device (not shown) outside the machine. The inside of the filtration drum 1 is maintained at a vacuum through a pipe line. As a result, the stock slurry in the stock slurry vat 4 that is in contact with the stock slurry of the filtration drum 1 is suction-filtered, and the filtrate is passed through the through-hole 2.
After passing through the filter cloth 3, it accumulates at the bottom of the filter drum 1, and a cake layer is formed on the surface of the filter cloth 3.

The filtrate collected in the filtration drum 1 is sucked by a filtrate pipe 6 that is suctioned under reduced pressure, and is sucked by a center pipe 5.
Is discharged outside the machine. Further, the cake layer formed on the filter cloth 3 rises with the rotation of the rotating drum 1,
At the cake washing position of the spray tube 12, the cake is washed with the washing liquid sprayed from the spray tube 12, and is further drained by the vacuum in the filtration drum 1 while descending with rotation.
The cake layer that has been drained is moved from the first slit 9 of the valve shoe 7 through the center pipe 5 and the valve bar 8 to the back surface of the cake layer at the position where the valve shoe 7 is disposed with the rotation of the rotary drum 1. The cake that has been peeled off by the blow gas injected to the
Is discharged out of the machine. The surface of the filter cloth 3 from which the cake layer has been removed is cleaned by the cleaning liquid sprayed from the filter cloth cleaning pipe 14 and the header pipe 11 connected to the cleaning liquid pipe.
The remaining cake adhered is removed by the cleaning liquid sprayed from the second slit 10 of the valve shoe 7 to the back side through the valve shoe 7, and the removed cake falls back into the stock slurry vat 4 with the cleaning liquid. By repeating the filtering operation, the filtering process is continuously performed.

With the progress of the above-mentioned filtration operation, the clogging of the filter cloth gradually progresses, and the filtration capacity is reduced. Therefore, the filtration step is stopped and the cleaning step by the cleaning means is performed. In the washing step, the flow rate of the undiluted slurry is measured by the undiluted slurry flow meter 21 provided in the undiluted slurry supply pipe, and when the measured value falls below a predetermined value, the filtration step is stopped by a control device (not shown). After the slurry in the stock slurry vat 4 is discharged to the reslurry tank 15, the cleaning liquid is jetted from the second slit 10 of the valve shoe 7 via the header pipe 11, and the cleaning liquid is jetted from the filter cloth cleaning pipe 14. The cleaning process is performed automatically. In addition, they are not automatically operated by the control device,
It can also be performed manually. Further, the washing step includes:
It is preferable to perform the process when the stock solution slurry flow rate is reduced to a flow rate less than 95% of the steady operation.

[0024]

According to the present invention, the number of operation stoppages is reduced when the filtration process is stopped and the washing step is performed by the washing means when the filtration capacity is reduced to a predetermined level or less with the elapse of the filtration operation. As little as possible,
Therefore, the present invention provides a single-chamber rotary filter that can be operated automatically without reducing the throughput during the entire operation time as much as possible and saves trouble.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a rotary single-chamber filter according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional rotary single-chamber filter.

[Explanation of symbols]

 1: Filtration drum 2: Liquid passage hole 3: Filter cloth 4: Stock solution slurry vat 5: Center pipe 6: Filtrate tube 7: Valve shoe 8: Valve bar 9: First slit 10: Second slit 11: Header tube 12: Cake washing Pipe 13: Cake chute 14: Filter cloth washing pipe 15: Reslurry tank 16: Stock solution slurry supply pump 17: Casing 18: Stirrer 19: Liquid level detector 20: Stock solution slurry flow control valve 21: Stock solution slurry flow meter

Claims (3)

[Claims] 1. A closed single-chamber filter drum having a large number of liquid passage holes formed in a circumferential surface thereof and a filter cloth stretched on the outer circumferential surface thereof is axially mounted on a center pipe. It is immersed in the stock slurry in the stock slurry vat, suction-filtered while stirring the stock slurry by the stirring means, and the filtrate filtered in the filter drum is discharged out of the machine with a filtrate pipe connected to the center pipe, and then filtered. In a rotary single-chamber filter, a cake layer formed on an outer peripheral surface is connected to the center pipe, and is separated and recovered by a pressure gas blown from a slit of a valve shoe slidingly contacting the inner peripheral surface of the filter drum. A liquid level detector for detecting a liquid level position in the raw liquid slurry vat, and a raw liquid slurry for measuring a raw liquid slurry flow rate to a raw liquid slurry supply pipe for supplying the raw liquid slurry to the raw liquid slurry vat. Rotating single-chamber filtration unit, characterized in that disposed between stock slurry flow rate control valve for controlling the stock slurry supply amount by over flow meter and the liquid level detector. 2. A closed single-chamber type filter drum having a plurality of liquid passage holes formed in a circumferential surface thereof and a filter cloth stretched on the outer circumferential surface thereof is axially mounted on a center pipe. It is immersed in the stock slurry in the stock slurry vat, suction-filtered while stirring the stock slurry by the stirring means, and the filtrate filtered in the filter drum is discharged out of the machine with a filtrate pipe connected to the center pipe, and then filtered. In a rotary single-chamber filter, a cake layer formed on an outer peripheral surface is connected to the center pipe, and is separated and recovered by a pressure gas blown from a slit of a valve shoe slidingly contacting the inner peripheral surface of the filter drum. The liquid level position in the stock slurry vat is detected by a liquid level detector, and the stock slurry supply amount is adjusted by the stock slurry flow control valve provided in the stock slurry supply pipe. -Control the liquid level in the vat to a predetermined position, measure the raw slurry flow rate with a raw slurry flow meter installed in the raw slurry supply pipe, and stop the filtration process when the measured value falls below a predetermined value. And performing a washing step by a washing means. 3. The method according to claim 2, wherein the filtration step is stopped and the washing step is performed by the washing means when the undiluted slurry flow rate measured by the undiluted slurry flow meter falls to less than 95% of the flow rate during the steady operation. A method for cleaning a rotary single-chamber filter according to the above.