A system and method for automatic recirculation feed of a filter press

Abstract

The embodiment of the present application provides a system and method for automatic circulating feeding of a filter press, and belongs to the technical field of solid-liquid separation. The system for automatic circulating feeding of the filter press comprises: a filter press (4) for receiving slurry to be filtered and performing filter pressing on the slurry; an online turbidimeter (8) for detecting the turbidity of filtrate pressed out by the filter press (4); a switch valve located in an outflow channel of the filtrate; and a control unit for controlling the switch valve to make the filtrate reflow to the filter press (4) to be filtered again when the turbidity is greater than a set value. The present application can reduce manual operation, improve the automation degree of turbid liquid circulating filter pressing, reduce occupational health risks and environmental protection risks, and is suitable for various filtering equipment such as ordinary plate and frame, vertical and box type filtering equipment which needs circulating filtration.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid-liquid separation, in particular to a system and method for automatic circulating feeding of a filter press. BACKGROUND

[0002] At present, filter presses are mostly used as solid-liquid separation equipment, and filter presses have been widely used in chemical industry, pharmaceutical industry, metallurgy, dye industry, food industry, brewing, ceramics and environmental protection industries. However, the working state of the filter press is not good in the early stage, especially before the formation of filter cake, the filtering effect of the filter press is not ideal, and the water is turbid. When the filter cake is formed, the filtering effect of the filter press reaches the best state, and the water is clear. In order to ensure the filtering effect, the initial turbidity of the filter press needs to be filtered again, and the existing technology mainly relies on manual identification of whether the initial turbidity needs to be filtered again and the manual operation of the circulating filtration of the turbidity.

[0003] The present application relates to the technical field of solid-liquid separation, in particular to a system and method for automatic circulating feeding of a filter press. SUMMARY

[0004] The purpose of the embodiment of the present application is to provide a device which detects the clarity of the filter liquid pressed out of the filter press by using an online turbidity meter, and controls the on-off valve by using a control unit to realize the automatic switching of the turbidity circulating feeding and the clear liquid discharging. The device reduces manual operation, improves the automation degree of the turbidity circulating filtration, reduces the occupational health risk and environmental protection risk, and is suitable for ordinary plate and frame type, vertical type, box type and other types of filtering equipment which need circulating filtration.

[0005] In order to achieve the above-mentioned purpose, the embodiment of the present application provides a system for automatic circulating feeding of a filter press, which comprises: a filter press for receiving slurry to be filtered and filtering the slurry; an online turbidity meter for detecting the turbidity of the filter liquid pressed out of the filter press; an on-off valve located in the outflow channel of the filter liquid; and a control unit for controlling the on-off valve when the turbidity is greater than a set value, so that the filter liquid is reflowed to the filter press for re-filtering.

[0006] Optionally, the on-off valve comprises a turbidity valve and a clear liquid valve, and when the turbidity is greater than a set value, the control unit controls the turbidity valve to open and the clear liquid valve to close, so that the filter liquid is reflowed to the filter press for re-filtering, wherein the opening of the turbidity valve can make the filter liquid reflow to the filter press, and the opening of the clear liquid valve can make the filter liquid flow to a clear liquid tank.

[0007] Optionally, before the filtrate is re-circulated to the filter press, the filtrate flows through a turbid liquid valve, a feed tank and a filter press pump in sequence, wherein the feed tank is used to store the slurry to be filtered, and the filter press pump is used to deliver the slurry to be filtered stored in the feed tank to the filter press.

[0008] Optionally, the system for automatic circulation feeding of the filter press further comprises a liquid collecting tank for receiving the filtrate pressed out of the filter press, a discharge pump for delivering the filtrate in the liquid collecting tank to the on-off valve, and a liquid level meter for monitoring the liquid level of the filtrate in the liquid collecting tank, wherein the control unit is further configured to control the discharge pump to be turned on when the liquid level of the liquid collecting tank is higher than a first preset liquid level, so that the filtrate flows to the on-off valve.

[0009] Optionally, the control unit automatically adjusts the frequency of the discharge pump according to the liquid level of the liquid collecting tank, so as to maintain the liquid level of the liquid collecting tank at a preset liquid level.

[0010] Optionally, when the liquid level meter detects that the liquid level of the liquid collecting tank is continuously lower than a second preset liquid level for a set time, the control unit controls the filter press pump and the discharge pump to be turned off, and controls the filter press to perform automatic unloading and automatic cleaning, wherein the second preset liquid level is lower than the first preset liquid level, and the filter press pump is used to deliver the slurry to be filtered to the filter press.

[0011] In another aspect, an embodiment of the present application provides a method for automatic circulation feeding of a filter press, wherein the filter press is used to receive slurry to be filtered and perform filter pressing on the slurry, and the method comprises: detecting the turbidity of the filtrate pressed out of the filter press; and when the turbidity is greater than a set value, controlling an on-off valve located in the outflow channel of the filtrate, so that the filtrate is re-circulated to the filter press for re-filtering.

[0012] Optionally, the on-off valve comprises a turbid liquid valve and a clear liquid valve, wherein the turbid liquid valve is turned on to enable the filtrate to be re-circulated to the filter press, and the clear liquid valve is turned on to enable the filtrate to flow to a clear liquid tank, and the control of the on-off valve located in the outflow channel of the filtrate, so that the filtrate is re-circulated to the filter press for re-filtering, comprises: when the turbidity is greater than a set value, the turbid liquid valve is controlled to be turned on and the clear liquid valve is controlled to be turned off, so that the filtrate is re-circulated to the filter press for re-filtering.

[0013] Optionally, the method for automatic circulating feeding of a filter press further comprises: monitoring the liquid level of filtrate in a collecting tank for receiving filtrate pressed out of the filter press; and in the case that the liquid level of the collecting tank is higher than a first preset liquid level, controlling the opening of a discharge pump, so that the filtrate flows to the switch valve, wherein the discharge pump is used to transport the filtrate in the collecting tank to the switch valve.

[0014] Optionally, the method for automatic circulating feeding of a filter press further comprises: automatically adjusting the frequency of the discharge pump according to the liquid level of the collecting tank, so as to maintain the liquid level of the collecting tank at a preset liquid level.

[0015] Optionally, the method for automatic circulating feeding of a filter press further comprises: when the liquid level of the collecting tank is continuously lower than a second preset liquid level for more than a set time, controlling the closing of the filter press pump and the discharge pump, and controlling the filter press to perform automatic unloading and automatic cleaning, wherein the second preset liquid level is lower than the first preset liquid level, and the filter press pump is used to transport slurry to be filtered to the filter press.

[0016] Compared with the prior art, the present application adopts an online turbidity meter to detect the turbidity of filtrate pressed out of a filter press, and controls the opening and closing of a switch valve through a control unit to realize the automatic switching of turbid liquid circulating feeding and clear liquid discharging. The device reduces manual operation, improves the automation degree of turbid liquid circulating filtration, and reduces occupational health risks and environmental protection risks, and is suitable for various types of filtration equipment, such as ordinary plate and frame type, vertical type, box type, etc., which need circulating filtration.

[0017] Other features and advantages of the embodiments of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific embodiments to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0019] Figure 1 is a system structure block diagram provided by the embodiments of the present application for automatic circulating feeding of a filter press.

[0020] Figure 2 is a system schematic diagram provided by the embodiments of the present application for automatic circulating feeding of a filter press.

[0021] Figure 3 is a method flowchart provided by the embodiments of the present application for automatic circulating feeding of a filter press.

[0022] EXPLANATION OF REFERENCE NUMERALS

[0023] 1 feed tank 2 filter press pump

[0024] 3. Pressure gauge 4. Filter press

[0025] 5. Collection tank; 6. Level gauge

[0026] 7. Discharge pump; 8. Online turbidity meter

[0027] 9. Turbid liquid valve 10. Clear liquid valve

[0028] 11 Clear Liquid Tanks Detailed Implementation

[0029] 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 for illustration and explanation only and are not intended to limit the scope of the present invention.

[0030] Figure 1 This is a system structure block diagram of an automatic circulating feeder for a filter press provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the system for automatic circulating feeding of a filter press includes: a filter press 4 for receiving slurry to be filtered and filtering the slurry; an online turbidity meter 8 for detecting the turbidity of the filtrate pressed out by the filter press 4; a switching valve located in the outflow channel of the filtrate; and a control unit for controlling the switching valve when the turbidity is greater than a set value, so that the filtrate flows back to the filter press 4 for further filtration.

[0031] Optional, Figure 2 The diagram shown is a schematic diagram of an automatic circulating feed system for a filter press provided by an embodiment of the present invention. (See attached diagram.) Figure 2 As shown, the slurry to be filtered is stored in the feed tank 1. When the filter press pump 2 is turned on, the slurry stored in the feed tank 1 is transported to the filter press 4, and the filter press 4 begins filtration. Optionally, the turbidity setting value is preferably 0.5 ntu, and the control unit is preferably a programmable logic controller (PLC). Figure 2 The pressure gauge 3 shown is used to monitor the feed pressure, and the switching valve includes... Figure 2 The filter press 4 includes a turbid liquid valve 9 and a clear liquid valve 10. Opening the turbid liquid valve 9 allows the filtrate to flow back to the filter press 4, and opening the clear liquid valve 10 allows the filtrate to flow to the clear liquid tank 11. The turbid liquid valve 9 and the clear liquid valve 10 can be pneumatic valves.

[0032] Specifically, when the filtrate pressed by the filter press 4 is transported to the online turbidimeter 8, the online turbidimeter 8 detects the turbidity of the filtrate and transmits the turbidity value to the PLC. When the PLC determines that the turbidity of the filtrate is greater than 0.5 ntu, the PLC controls the turbid liquid valve 9 to open and the clear liquid valve 10 to close, so that the filtrate flows back to the feed tank 1 and is filtered again by the filter press 4.

[0033] Referring to Figure 2 As shown in the system schematic diagram for automatic circulating feeding of a filter press, the system for automatic circulating feeding of a filter press further comprises a collecting tank 5 for receiving the filtrate pressed by the filter press 4, a discharge pump 7 for transporting the filtrate in the collecting tank 5 to the on-off valve, and a liquid level meter 6 for monitoring the liquid level of the filtrate in the collecting tank 5, wherein the control unit is further configured to control the discharge pump 7 to open when the liquid level of the collecting tank 5 is higher than a first preset liquid level, so that the filtrate flows to the on-off valve.

[0034] Optionally, the first preset liquid level is preferably 90% full. After the filter press starts, the filtrate pressed by the filter press 4 enters the collecting tank 5, and when the liquid level meter 6 detects that the liquid level of the filtrate in the collecting tank 5 is higher than 90% full, the PLC controls the discharge pump 7 to open, so that the filtrate flows to the online turbidimeter 8. In the early stage of filter pressing, the online turbidimeter 8 detects that the turbidity of the filtrate is greater than 0.5 ntu, and the PLC controls the turbid liquid valve 9 to open and the clear liquid valve 10 to close, so that the filtrate flows back to the feed tank 1 through the turbid liquid valve 9, realizing turbid liquid circulating filtration.

[0035] As Figure 2 shown, the liquid level meter 6 and the discharge pump 7 are interlocked. The liquid level meter 6 monitors the liquid level of the collecting tank 5, and the PLC automatically adjusts the frequency of the discharge pump 7 according to the liquid level to maintain the liquid level of the collecting tank 5 at a preset liquid level. When the liquid level meter 6 detects that the liquid level of the collecting tank 5 is continuously lower than a second preset liquid level for more than a set time, the control unit controls the filter press pump 2 and the discharge pump 7 to close and controls the filter press 4 to perform automatic unloading and automatic cleaning.

[0036] Optionally, the preset liquid level is preferably 50% full, the second preset liquid level is preferably 20% full, and the set time is preferably 10s. Specifically, during the pressure filtration operation, the liquid level meter 6 monitors the liquid level of the collecting tank 5 at any time, and the PLC automatically adjusts the frequency of the discharge pump 7 according to the liquid level of the collecting tank 5, thereby controlling the water discharge speed of the collecting tank 5, so that the liquid level of the collecting tank 5 is maintained at a 50% full liquid level. When the liquid level meter 6 monitors that the liquid level of the collecting tank 5 is continuously lower than 20% full liquid level for more than 10s, the PLC determines that the filter press 4 is full or the feed tank 1 is empty, at which time the PLC controls the pressure filtration pump 2 and the discharge pump 7 to be closed, and controls the filter press 4 to perform automatic unloading and automatic cleaning. When the PLC determines that the feed tank 1 is empty, it indicates that the solid-liquid separation operation is completed, so the PLC needs to control the filter press 4 to perform automatic unloading and automatic cleaning, which is the same as the operation after determining that the filter press 4 is full.

[0037] Optionally, when the filter cake is formed, the online turbidity meter 8 detects that the turbidity of the filtrate is less than 0.5ntu, the PLC controls the turbid liquid valve 9 to be closed and the clear liquid valve 10 to be opened, the filtrate flows through the clear liquid valve 10 into the clear liquid tank 11, and automatic collection of clear liquid is realized.

[0038] Optionally, the first preset liquid level, the second preset liquid level, and the turbidity set value of the online turbidity meter 8 can be set in the PLC according to the working conditions

[0039] Figure 3 The method for automatically circulating feeding of the filter press provided by the embodiment of the application is shown in the flowchart, and the method comprises the following steps.

[0040] S10, detecting the turbidity of the filtrate pressed out by the filter press 4.

[0041] S20, when the turbidity is greater than a set value, controlling a switch valve located in the outflow channel of the filtrate, so that the filtrate is returned to the filter press 4 for re-filtering.

[0042] S30, monitoring the liquid level of the filtrate in the collecting tank 5 for receiving the filtrate pressed out by the filter press 4.

[0043] S40, when the liquid level of the collecting tank 5 is higher than a first preset liquid level, controlling the discharge pump 7 to be opened, so that the filtrate flows to the switch valve.

[0044] S50, automatically adjusting the frequency of the discharge pump 7 according to the liquid level of the collecting tank 5, so as to maintain the liquid level of the collecting tank 5 at a preset liquid level.

[0045] S60, when the liquid level of the collecting tank 5 continues to be lower than a second preset liquid level for a set time, controlling the filter press pump 2 and the discharge pump 7 to be closed, and controlling the filter press 4 to perform automatic discharge and automatic cleaning, wherein the second preset liquid level is lower than the first preset liquid level, and the filter press pump 2 is used to deliver slurry to be filtered to the filter press 4.

[0046] The method for automatic cyclic feeding of a filter press described above is similar to the embodiments of the system for automatic cyclic feeding of a filter press described above, and will not be described again here.

[0047] It should be noted that the terms "comprising", "containing", or any other variant thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a" does not exclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0048] The above is only an embodiment of the present application and is not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of claims of the present application.

Claims

1. A system for automatic circulating feeding of a filter press, characterized in that, include: A filter press (4) is used to receive the slurry to be filtered and to filter the slurry by pressure. An online turbidity meter (8) is used to detect the turbidity of the filtrate pressed out by the filter press (4); A switching valve is located within the outflow channel of the filtrate; as well as The control unit is used to control the switching valve when the turbidity is greater than the set value, so that the filtrate is returned to the filter press (4) for further filtration; The collection tank (5) is used to receive the filtrate pressed out by the filter press (4); The discharge pump (7) is used to deliver the filtrate in the collection tank (5) to the switch valve; and A level gauge (6) is used to monitor the level of the filtrate in the collection tank (5). The control unit is also used to control the discharge pump (7) to turn on when the liquid level in the collection tank (5) is higher than the first preset liquid level, so that the filtrate flows to the switch valve; When the level gauge (6) detects that the liquid level in the collection tank (5) is continuously lower than the second preset liquid level for more than a set time, the control unit controls the filter press pump (2) and the discharge pump (7) to shut down, and controls the filter press (4) to perform automatic unloading and automatic cleaning, wherein the second preset liquid level is lower than the first preset liquid level, and the filter press pump (2) is used to transport the slurry to be filtered to the filter press (4).

2. The system for automatic circulating feeding of a filter press according to claim 1, characterized in that, The switching valve includes a turbid liquid valve (9) and a clear liquid valve (10). When the turbidity is greater than the set value, the control unit controls the turbid liquid valve (9) to open and the clear liquid valve (10) to close, so that the filtrate flows back to the filter press (4) for further filtration. The opening of the turbid liquid valve (9) enables the filtrate to flow back to the filter press (4), and the opening of the clear liquid valve (10) enables the filtrate to flow to the clear liquid tank (11).

3. The system for automatic circulating feeding of a filter press according to claim 2, characterized in that, Before the filtrate is returned to the filter press (4), the filtrate flows through the turbid liquid valve (9), the feed tank (1) and the filter press pump (2) in sequence. The feed tank (1) is used to store the slurry to be filtered, and the filter press pump (2) is used to transport the slurry to be filtered stored in the feed tank (1) to the filter press (4).

4. The system for automatic circulating feeding of a filter press according to claim 1, characterized in that, The control unit automatically adjusts the frequency of the discharge pump (7) according to the liquid level of the collection tank (5) to maintain the liquid level of the collection tank (5) at a preset level.

5. A method for automatic circulating feeding of a filter press (4), wherein the filter press (4) is used to receive slurry to be filtered and to filter the slurry, characterized in that, The method includes: The turbidity of the filtrate pressed out by the filter press (4) is detected; and When the turbidity is greater than the set value, the switch valve located in the outflow channel of the filtrate is controlled so that the filtrate flows back to the filter press (4) for further filtration. Monitor the liquid level of the filtrate in the collection tank (5) used to receive the filtrate pressed out by the filter press (4); and When the liquid level in the collection tank (5) is higher than the first preset liquid level, the discharge pump (7) is turned on so that the filtrate flows to the switch valve, wherein the discharge pump (7) is used to transport the filtrate in the collection tank (5) to the switch valve. When the liquid level in the collection tank (5) is lower than the second preset liquid level for a set time, the filter press pump (2) and the discharge pump (7) are turned off, and the filter press (4) is controlled to perform automatic unloading and automatic cleaning. The second preset liquid level is lower than the first preset liquid level, and the filter press pump (2) is used to transport the slurry to be filtered to the filter press (4).

6. The method for automatic circulating feeding of a filter press according to claim 5, characterized in that, The switching valve includes a turbid liquid valve (9) and a clear liquid valve (10), wherein opening the turbid liquid valve (9) allows the filtrate to flow back to the filter press (4), and opening the clear liquid valve (10) allows the filtrate to flow to the clear liquid tank (11). The control of the switching valve located in the outflow channel of the filtrate, so that the filtrate flows back to the filter press (4), includes: When the turbidity is greater than the set value, the turbid liquid valve (9) is opened and the clear liquid valve (10) is closed, so that the filtrate is returned to the filter press (4) for further filtration.

7. The method for automatic circulating feeding of a filter press according to claim 5, characterized in that, The method also includes: The frequency of the discharge pump (7) is automatically adjusted according to the liquid level of the collection tank (5) to maintain the liquid level of the collection tank (5) at a preset level.

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