CN111632425A - Filter automatic backwashing equipment and backwashing method - Google Patents

Abstract

The invention relates to the field of manufacturing of filtering equipment in the coal chemical industry, and discloses automatic back flushing equipment of a filter and a back flushing method thereof, wherein the automatic back flushing equipment of the filter comprises a filter body (1) with a filter element (2), the filter body is respectively connected with a pulse gas generator (5) and a back flushing pump (9), and the pulse gas generator inputs pulse gas into the filter body and forms pulse vortex inside the filter body; the backflushing pump is used for pumping the filter liquid into the filter body to form backflushing liquid and soaking the filter element in the backflushing liquid for backflushing; the filter body is provided with an output pipeline for discharging a gas-liquid mixture of the pulse gas and the backflushing liquid. According to the invention, under the conditions that an end cover at the top of the filter is not disassembled and the filter element is not required to be taken out, the filter liquid is directly used as the backflushing liquid to carry out backflushing on the filter element in the filter body, so that the online regeneration of the filter system is realized; short flushing time, simple operation, thorough cleaning, prolonged service life of the filter element and reduced operation cost of the equipment.

Description

Filter automatic backwashing equipment and backwashing method

technical field

The invention relates to filtering equipment in the coal chemical industry, in particular to automatic backwashing equipment for filters and a backwashing method thereof.

Background technique

The filter is a kind of equipment widely used in the coal chemical industry, which is mainly used to remove impurities remaining in solutions such as water or methanol. Among them, the lean methanol filter is a filter commonly used in the low-temperature methanol washing process of coal chemical industry to filter impurities in methanol solution. Due to the large amount of impurities in the system, after running for a period of time, the impurities on the filter screen will accumulate to form a filter cake. When the thickness of the filter cake increases to a certain extent, the pressure difference on both sides of the filter blockage will rise to the alarm value, and the filtration speed and filtration effect will decrease significantly, which will seriously affect the normal operation of the process system and equipment.

In the prior art, ordinary lean methanol filters do not have the function of backwashing and cannot realize on-line regeneration of the filtration system. The existing filter element cleaning methods include two: the first one is when the filter pressure difference reaches a set value, open the flange end cover on the top of the filter, and take out the filter element for cleaning. Generally, steam, high-pressure water gun, brush, etc. are used to backflush and clean the filter element one by one, or use an ultrasonic cleaner to clean it. Not only is it time-consuming and labor-intensive, but also it is easy to cause losses to the filter element, affecting the life of the filter element and increasing the operating cost. The second is that when the pressure difference of the filter reaches the set value, the original liquid is drained, and the gas is backflushed. Since the permeable area of the filter element after decake is greater than or equal to the inlet diameter, the gas starts to take shortcuts, resulting in the filter cake. Without sufficient power, the filter cake is stuck on the surface of the filter element, and the flange end cover on the top of the filter still needs to be opened for manual cleaning. The effect of backflushing and removing the cake is particularly poor. It affects the normal operation of the system, and the replacement of the filter element is frequent and the cost is high.

Therefore, it is an urgent problem to develop a filter with backwash function, which can realize the regeneration of the filter system without removing the top end cover of the filter and removing the filter element for cleaning.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a filter automatic backwashing device and a backwashing method thereof in order to overcome the problems of the prior art, such as long time consumption, high labor intensity, incomplete cleaning, easy loss to the filter element, and influence on the life of the filter element. Without dismantling the top end cover of the filter and taking out the filter element, the filtrate is directly used as the backflush to reverse the filter element in the filter body through the pulse gas generator and the backflush pump respectively connected to the filter body. Flushing to realize online regeneration of the filter system; the flushing time is short, the operation is simple, and the cleaning is thorough, which will not cause damage to the filter element, improve the service life of the filter element and reduce the operating cost of the equipment.

In order to achieve the above purpose, one aspect of the present invention provides an automatic backwashing device for a filter, comprising a filter body with a filter element, the filter body is respectively connected with a pulse gas generator and a backflush pump, and the pulse gas generator The filter body inputs pulse gas into the filter body and forms a pulse vortex inside it; the backflush pump is used to pump the filtrate into the filter body to form backflush liquid and soak the filter element in the filter body. Backflushing is performed in the backflushing liquid; the filter body is provided with an output pipeline for discharging the gas-liquid mixture of the pulse gas and the backflushing liquid.

Preferably, the output pipeline is connected to a gas-liquid separator, the gas-liquid separator is provided with a gas-phase output end and a liquid-phase output end, and the gas-phase output end discharges the gas separated by the gas-liquid separator out, the liquid phase output end is communicated with the backflush liquid collection tank.

Preferably, the filter body is provided with a differential pressure transmitter, a liquid level transmitter and an overflow pipe respectively, and the overflow pipe is provided with a liquid for preventing the liquid level in the filter body from being too high. A position control valve is provided, and the overflow pipeline is communicated with the backflush liquid collection tank.

Preferably, in the backflushing state, the volume occupied by the gas-liquid mixture in the filter body is less than or equal to 80%-90% of the volume of the filter body; in the emptying state, in the filter body The volume occupied by the gas-liquid mixture is ≥ 10%-15% of the volume of the filter body.

Preferably, the filter body is provided with a sewage pipe, a sewage control valve is provided on the sewage pipe, and the sewage pipe is communicated with the backflushing liquid collection tank.

Preferably, an automatic controller is included, and the automatic controller is connected with the differential pressure transmitter and the liquid level transmitter on the filter body;

The filter body is respectively provided with a filtrate inlet pipeline and a filtrate outlet pipeline, the filtrate inlet pipeline is provided with an inlet control valve, the filtrate outlet pipeline is provided with an outlet control valve, and the inlet a control valve and the outlet control valve are connected to the automatic controller;

The backflushing pump is connected with the filter body through a backflushing pipeline, and a backflushing control valve is provided on the backflushing pipeline, and the backflushing control valve is connected with the automatic controller.

Preferably, the filtrate is methanol, and the pulse gas is nitrogen.

A second aspect of the present invention provides a backwashing method for the filter automatic backwashing device as described above, comprising the following steps:

Step 100: inputting pulsed gas into the filter body and forming a pulsed vortex in the filter body;

Step 200: backflushing the filtrate into the filter body, so that the filter element in the filter body is backwashed by the pulse eddy current under the immersion of the backflush;

Step 300: After the backwashing is continued for a predetermined time, the gas-liquid mixture in the filter body is discharged.

Preferably, it also includes step 400:

The discharged gas-liquid mixture is subjected to gas-liquid separation, the separated gas-phase substances are discharged, the separated liquid-phase substances are collected, and the backwashed impurities are discharged.

Preferably, before step 100, step 090 is further included:

The filtrate to be filtered is input into the filter body, impurities larger than the pore size of the filter screen in the filter element are retained, and the filtered clean filtrate is discharged from the filter body.

Preferably, the gas pressure range of the pulsed gas in the step 100 is: 0.15-0.8MPa.

Preferably, the step 200 further includes:

When the filtrate is backflushed into the filter body and the gas-liquid mixture in the filter body is discharged, the liquid level in the filter body is monitored in real time, and when the liquid level reaches the threshold range, Stop filtrate backflushing or gas-liquid mixture discharge.

Preferably, the filtered and clean filtrate discharged from the filter body is backflushed into the filter body in the step 200 .

Preferably, the predetermined time in the step 300 is the time taken for the pressure difference in the filter body to recover to below 25 kPa.

Through the above technical solutions, the present invention directly uses the filtrate as the backflush to filter the filter through the pulse gas generator and the backflush pump, which are respectively connected to the filter body, without disassembling the top end cover of the filter and without taking out the filter element. The filter element in the filter body is backwashed to realize the online regeneration of the filter system; the flushing time is short, the operation is simple, and the cleaning is thorough, which will not cause damage to the filter element, improve the service life of the filter element and reduce the operating cost of the equipment.

Description of drawings

FIG. 1 is a schematic diagram of the overall structure of an automatic filter backwashing device in an embodiment of the present invention.

Description of reference numerals

1. Filter body; 2. Filter element; 3. Differential pressure transmitter; 4. Liquid level transmitter; 5. Pulse gas generator; 6. Automatic controller; 7. Backflush liquid collection tank; 8. Gas Liquid separator; 9. Backflushing pump; 10. Blowdown control valve; 11. Inlet control valve; 12. Outlet control valve; 13. Backflushing control valve; valve; 17, liquid level control valve; 18, recoil outlet valve.

Detailed ways

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention.

In the present invention, unless otherwise stated, the directional words used such as "up, down, left and right" generally refer to up, down, left and right as shown with reference to the accompanying drawings; "inside, outside" Usually refers to the inside and outside relative to the contour of each component itself; "far, near" usually refers to the distance relative to the contour of each component itself.

As shown in FIG. 1, one aspect of the present invention provides an automatic backwashing device for a filter, comprising a filter body 1 with a filter element 2, and the filter body 1 is connected with a pulse gas generator 5 and a backwash pump 9 respectively, The pulsed gas generator 5 inputs pulsed gas into the filter body 1 and forms a pulsed vortex inside it; the backflush pump 9 is used to pump the filtrate into the filter body 1 to form a backflush liquid The filter element 2 is immersed in the backflushing liquid for backflushing; the filter body 1 is provided with an output pipeline for discharging the gas-liquid mixture of the pulsed gas and the backflushing liquid. It can be seen from the above content that in the present invention, without removing the top end cover of the filter and taking out the filter element, the filtrate is directly used as the backflush to filter the filter through the pulse gas generator and the backflush pump respectively connected to the filter body. The filter element in the filter body is backwashed to realize the online regeneration of the filter system; the flushing time is short, the operation is simple, and the cleaning is thorough, which will not cause damage to the filter element, improve the service life of the filter element and reduce the operating cost of the equipment.

Specifically, in order to facilitate further gas-liquid separation of the gas-liquid mixture output from the output pipeline, the output pipeline is connected to the gas-liquid separator 8, and the gas-liquid separator 8 is provided with a gas-phase output end and a liquid-liquid separator. Phase output end, the gas phase output end discharges the gas separated by the gas-liquid separator 8 through the gas phase outlet 15 , and the liquid phase output end is communicated with the backflush liquid collection tank 7 .

In order to ensure the backwashing effect and maintain the liquid level in the filter body 1 at a safe position throughout the treatment process, the filter body 1 is provided with a differential pressure transmitter 3, a liquid level transmitter 4 and an overflow transmitter 3 respectively. The overflow pipeline is provided with a liquid level control valve 17 for preventing the liquid level in the filter body 1 from being too high, and the overflow pipeline communicates with the backflush liquid collection tank 7 . Usually, in the backflushing state, the volume occupied by the gas-liquid mixture in the filter body 1 is ≤80%-90% of the volume of the filter body 1; in the emptying state, the filtering The volume occupied by the gas-liquid mixture in the filter body 1 is greater than or equal to 10%-15% of the volume of the filter body 1 .

In order to discharge the sewage in time, the filter body 1 is provided with a sewage discharge pipe, and the sewage discharge pipe is provided with a sewage discharge control valve 10 , and the sewage discharge pipe is communicated with the backflush liquid collection tank 7 .

In order to prevent the pressure in the filter body 1 from exceeding the standard, a venting pipeline 14 is provided on the top of the filter body 1 to realize the venting protection for the filter body 1 when the pressure is too high.

In order to effectively control the cut-off and conduction of each pipeline, the filter automatic backwashing equipment also includes an automatic controller 6, the automatic controller 6 and the differential pressure transmitter 3 on the filter body 1 and the The liquid level transmitter 4 is connected; the filter body 1 is respectively provided with a filtrate inlet pipeline and a filtrate outlet pipeline, and an inlet control valve 11 is provided on the filtrate inlet pipeline, and the filtrate An outlet control valve 12 is provided on the outlet pipeline, and the inlet control valve 11 and the outlet control valve 12 are connected to the automatic controller 6; the backflush pump 9 passes through the backflush pipeline and the filter body 1 The backflushing pipeline is provided with a backflushing control valve 13 , and the backflushing control valve 13 is connected to the automatic controller 6 .

It should be noted that the filter automatic backwashing device provided by the present invention can be applied to a variety of filtrates, and the pulse gas can also be a variety of gases. In the embodiment shown in FIG. 1 , the filtrate is Methanol (or water, ethylene glycol), the pulse gas is nitrogen (or carbon dioxide, argon). In addition, under normal circumstances, the filter element 2 of the filter is cylindrical, and the filter element 2 can be a mechanical filter screen, a ceramic membrane or a sintered filter element.

The second aspect of the present invention provides a backwashing method for the filter automatic backwashing device as described above. Generally speaking, the method includes the following steps:

Step 100: inputting pulsed gas into the filter body to form a pulsed vortex in the filter body;

Step 200: backflushing the filtrate into the filter body, so that the filter element in the filter body is backwashed by the pulse eddy current under the immersion of the backflush;

Step 300: After the backwashing is continued for a predetermined time, the gas-liquid mixture in the filter body is discharged.

In order to facilitate the reuse of the filtrate, the method further includes step 400:

The discharged gas-liquid mixture is subjected to gas-liquid separation, the separated gas-phase substances are discharged, the separated liquid-phase substances are collected, and the backwashed impurities are discharged.

Under normal circumstances, the gas pressure range of the pulsed gas in the step 100 is: 0.15-0.8MPa.

Since the backflushing liquid and the filtrate use the same liquid, the backwashing can be carried out directly after the filtration is completed. Therefore, the step 100 can also include step 090:

The filtrate to be filtered is input into the filter body, impurities larger than the pore size of the filter screen in the filter element are retained, and the filtered clean filtrate is discharged from the filter body.

More specifically, the step 200 further includes:

When the filtrate is backflushed into the filter body and the gas-liquid mixture in the filter body is discharged, the liquid level in the filter body is monitored in real time, and when the liquid level reaches the threshold range, Stop filtrate backflushing or gas-liquid mixture discharge.

In order to reduce the cost, the filtered and clean filtrate discharged from the filter body is backflushed into the filter body in the step 200, so as to realize the reuse of the filtrate.

The predetermined time in the step 300 is: the time taken for the pressure difference in the filter body to recover to below 25 kPa.

As can be seen from the above content, the present invention provides an automatic backwashing device for a filter and a backwashing method thereof. The pulsed gas is formed into a pulsed kinetic energy and sent into the filter body, and the filter element is immersed in the filtrate for backwashing; It enters the filter sideways, and uses kinetic energy to form eddy currents. Under the dual action of gas and liquid, the surface of the filter element is physically washed to remove impurities; the automatic control system is used to adjust the backwashing process. In the liquid recovery stage and the automatic adjustment stage, the filter element of the filter is backwashed in the filter body, so that the filter element in the filter can be efficiently regenerated without disassembling the top end cover of the filter, which solves the problem in the prior art. It takes a long time, the operation and maintenance are labor-intensive, and the cleaning is not thorough, which is easy to cause damage to the filter element, affect the life of the filter element and increase the operating cost and many other problems.

The backwashing method of the filter automatic backwashing device provided by the present invention will be described in detail below with reference to FIG. 1 .

First, it includes the filtration stage: the raw methanol enters the filter body 1 through the inlet control valve 11 on the pipeline, the impurities larger than the pore size of the filter screen are trapped under the action of the filter element 2, and the filtered clean methanol passes through the outlet control valve on the pipeline. 12 discharge.

Next, enter the backwashing stage: use the pulse gas generator 5 to form pulse kinetic energy of pulse nitrogen gas, form a pulse vortex in the filter body 1, and transport it into the filter body 1 through the pulse gas inlet. Start the backflush pump 9, and send the backflush liquid through the backflush pump 9 and the backflush control valve 13 on the pipeline from the side to the filter body 1 through the backflush liquid inlet. Backwash with methanol solution.

Then, enter the backflush recovery stage: the backflush liquid is discharged into the gas-liquid separator 8 through the backflush gas-liquid outlet through the backflush liquid outlet valve 18 on the pipeline to separate the pulsed gas from the backflush liquid. The gas phase at the top of the gas-liquid separator is discharged through the gas phase outlet 15, and the bottom liquid phase outlet is transported to the backflushing liquid collection tank 7 through the liquid phase outlet valve 16 to recover the flushing liquid. At the same time, the sewage control valve at the bottom of the filter is communicated with the backflush collection tank, and the slag-containing methanol is collected in the backflush collection tank.

The above processes are all realized by automatic adjustment. Specifically, in practical applications, when the pressure difference of the filter is obtained through the pressure gauge or pressure transmitter and rises to the alarm value, the pressure difference transmitter 3 outputs the pressure difference signal to the alarm value. The automatic controller 6, the automatic controller 6 outputs the control signal according to the preset program, closes the inlet control valve 11 and the outlet control valve 12, opens the backflush control valve 13 and the blowdown control valve 10 to start flushing, and passes the liquid level transmitter 4 Monitor filter cartridge fluid level. When the liquid level transmitter shows the full scale, close the blowdown control valve 10 and keep the inlet control valve 11 open. After the backwashing device is pressurized for a delay, the blowdown control valve 10 is automatically opened to form a backwashing blasting force, which quickly removes the The impurities accumulated on the surface of the filter element 2 of the filter are washed away. The backwashing time can be determined according to the pressure recovery of the differential pressure transmitter 3, for example: when the differential pressure transmitter shows below 25kpa, that is, the backwashing is over; if it is still higher than 25kpa, repeat the flushing until it reaches Below 25kpa. When the pressure of the differential pressure transmitter 3 returns to normal, that is: below 25kpa, the automatic controller 6 outputs a control signal, opens the inlet control valve 11 and the outlet control valve 12, closes the inlet control valve 11 and the blowdown control valve 10, and ends Filter 2 backflush process and restart filtration.

To sum up, the filter automatic backwashing equipment and its backwashing method provided by the present invention are reasonably set up and easy to implement, which can realize online efficient regeneration of the filter element without disassembling the filter, and reduce the operation and maintenance of the equipment. It can meet the requirements of water and liquid backwashing and filtration. At the same time, the automatic control system is used to automatically control the backwashing process, which greatly reduces human resources and labor intensity and improves work efficiency; during the backwashing process The liquid level in the filter and the backwashing time can be adjusted, and the operation is convenient and stable.

The preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, for example, methanol and nitrogen can be replaced with other filtrate and gas. In order to avoid unnecessary repetition, the present invention will not describe various possible combinations. However, these simple modifications and combinations should also be regarded as the contents disclosed in the present invention, and all belong to the protection scope of the present invention.

Claims (15)

1. An automatic back-flushing device of a filter comprises a filter body (1) with a filter element (2), and is characterized in that the filter body (1) is respectively connected with a pulse gas generator (5) and a back-flushing pump (9), and the pulse gas generator (5) inputs pulse gas into the filter body (1) and forms a pulse vortex inside the filter body; the backflushing pump (9) is used for pumping the filtrate into the filter body (1) to form backflushing liquid and soaking the filter element (2) in the backflushing liquid for backflushing; the filter body (1) is provided with an output pipeline for discharging a gas-liquid mixture of the pulse gas and the backflushing liquid.

2. The automatic backwashing apparatus for filters of claim 1, wherein the output line is connected to a gas-liquid separator (8), the gas-liquid separator (8) having a gas phase output for discharging gas separated by the gas-liquid separator (8) and a liquid phase output for communicating with a backwashing liquid collection tank (7).

3. The automatic backwashing device of the filter of claim 1, wherein the filter body (1) is provided with a differential pressure transmitter (3), a liquid level transmitter (4) and an overflow pipe, the overflow pipe is provided with a liquid level control valve (17) for preventing the liquid level in the filter body from being too high, and the overflow pipe is communicated with the backwashing liquid collecting tank (7).

4. The automatic backwashing apparatus for filters of claim 1, wherein in a backwashing state, a volume occupied by the gas-liquid mixture in the filter body (1) is less than or equal to 80-90% of the volume of the filter body; in the emptying state, the volume occupied by the gas-liquid mixture in the filter body (1) is more than or equal to 10-15% of the volume of the filter body.

5. The automatic backwashing device of the filter of claim 2, wherein a blowdown pipe is arranged on the filter body (1), a blowdown control valve (10) is arranged on the blowdown pipe, and the blowdown pipe is communicated with the backwashing liquid collecting tank (7).

6. The automatic backwashing device of the filter of claim 3, comprising an automatic controller (6), wherein the automatic controller (6) is connected with the differential pressure transmitter (3) and the liquid level transmitter (4) on the filter body (1);

a filtrate inlet pipeline and a filtrate outlet pipeline are respectively arranged on the filter body (1), an inlet control valve (11) is arranged on the filtrate inlet pipeline, an outlet control valve (12) is arranged on the filtrate outlet pipeline, and the inlet control valve (11) and the outlet control valve (12) are connected with the automatic controller (6);

the backflushing pump (9) is connected with the filter body (1) through a backflushing pipeline, a backflushing control valve (13) is arranged on the backflushing pipeline, and the backflushing control valve (13) is connected with the automatic controller (6).

7. The automatic filter backwash apparatus according to claim 1, wherein the filtrate is methanol.

8. The automatic filter backwash apparatus according to claim 1, wherein the pulse gas is nitrogen gas.

9. A backwashing method of an automatic filter backwashing apparatus according to any of claims 1 to 8, comprising the steps of:

step 100: inputting pulse gas into the filter body and forming pulse vortex in the filter body;

step 200: backflushing the filtrate into the filter body, so that the filter element in the filter body is backflushed through the pulse vortex under the soaking of the backflushing solution;

step 300: and continuously performing back flushing and discharging the gas-liquid mixture in the filter body after the preset time is reached.

10. The backwashing method of the automatic filter backwashing apparatus according to claim 9, further comprising the step 400 of:

and carrying out gas-liquid separation on the discharged gas-liquid mixture, discharging the separated gas-phase substances, collecting the separated liquid-phase substances, and discharging the impurities after back washing.

11. The backwash method of automatic filter backwash equipment as defined in claim 9, wherein said step 100 is preceded by the step 090 of:

and inputting the filtrate to be filtered into the filter body, intercepting impurities larger than the pore size of the filter screen in the filter element, and discharging the filtered clean filtrate from the filter body.

12. The backwashing method of the automatic filter backwashing apparatus according to claim 9, wherein the gas pressure of the pulse gas in the step 100 is in a range of: 0.15-0.8 MPa.

13. The backwash method of filter automatic backwash equipment as claimed in claim 9, wherein said step 200 further comprises:

when the filtering liquid is backflushed into the filter body and the gas-liquid mixture in the filter body is discharged, the liquid level in the filter body is monitored in real time, and when the liquid level reaches a threshold range, the backflushing of the filtering liquid or the discharge of the gas-liquid mixture is stopped.

14. The backwash method of filter automatic backwash equipment as claimed in claim 11, wherein the filtered clean filtrate discharged from the filter body is backwashed into the filter body in the step 200.

15. The backwashing method of said automatic filter backwashing apparatus according to claim 9, wherein said predetermined time in said step 300 is: the time it takes for the pressure differential within the filter body to recover below 25 kpa.

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