System and method for automatic circulating feeding of filter press

Abstract

The embodiment of the invention provides a system and a 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 the filter press (4) used for receiving slurry to be filtered and carrying out filter pressing on the slurry; the online turbidimeter (8) is used for detecting the turbidity of the filtrate pressed by the filter press (4); the switch valve is positioned in the filtrate outflow channel; and the control unit is used for controlling the switch valve when the turbidity is greater than a set value, so that the filtrate flows back to the filter press (4) again, and the filter press (4) is filtered again. Manual operation can be reduced, the automation degree of circulating filter pressing of turbid liquid is improved, occupational health risks and environmental protection risks are reduced, and the device is suitable for various filtering devices with circulating filtering requirements such as a common plate frame type filtering device, a vertical filtering device and a box type filtering device.

Description

Technical Field

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

[0002] At present, filter presses are mostly used as solid-liquid separation equipment, and filter presses have been widely used in chemical, pharmaceutical, metallurgical, dye, food, brewing, ceramic and environmental protection industries. However, filter presses generally have poor working conditions in the early stage, especially before the filter cake is formed, the filtering effect of the filter press is not ideal, and the effluent is turbid. When the filter cake is formed, the filtering effect of the filter press reaches the best state, and the effluent is clear. In order to ensure the filtering effect, the initial turbid liquid needs to be filtered again, and the existing technology mainly relies on manual identification of whether the initial turbid liquid needs to be filtered again, and the cyclic filtration of the turbid liquid needs to be completed manually.

[0003] The inventors of this application found in the process of realizing the present invention that the above schemes of the prior art have a low degree of automation and have certain occupational health risks and environmental risks. In addition, the existing filter press automation technology mainly focuses on automatic plate pulling, automatic unloading and automatic cleaning of filter cloth, and cannot well realize the automatic circulation feeding technology of the initial turbid liquid of the filter press. Summary of the invention

[0004] The purpose of the embodiment of the present invention is to provide a device that uses an online turbidity meter to detect the clarity of the filtrate pressed out of the filter press, and controls the switch valve through a control unit to achieve automatic switching of turbid liquid circulation feeding and clear liquid discharge. The device reduces manual operation, improves the degree of automation of turbid liquid circulation filtration, and reduces occupational health risks and environmental risks. It is suitable for various types of filtering equipment that require circulation filtration, such as ordinary plate-and-frame, vertical, and box-type filtering equipment.

[0005] In order to achieve the above-mentioned purpose, an embodiment of the present invention provides a system for automatic circulation feeding of a filter press, the system comprising: a filter press, for receiving slurry to be filtered and filtering the slurry; an online turbidity meter, for detecting the turbidity of the filtrate pressed out by the filter press; a switch valve, located in the outflow channel of the filtrate; and a control unit, for controlling the switch valve when the turbidity is greater than a set value, so that the filtrate flows back to the filter press to be filtered again.

[0006] Optionally, the switch valve includes a turbid liquid valve and a clear liquid valve. When the turbidity is greater than a set value, the control unit controls the turbid liquid valve to open and the clear liquid valve to close, so that the filtrate flows back to the filter press for re-filtration. Opening the turbid liquid valve can allow the filtrate to flow back to the filter press, and opening the clear liquid valve can allow the filtrate to flow to the clear liquid tank.

[0007] Optionally, before the filtrate flows back to the filter press, the filtrate flows successively through a turbid liquid valve, a feed tank and a filter press pump, wherein the feed tank is used to store the slurry to be filtered, and the filter press pump is used to transport 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 also includes: a liquid collecting tank for receiving the filtrate pressed out of the filter press; a discharge pump for conveying the filtrate in the liquid collecting tank to the switch valve; and a liquid level meter for monitoring the liquid level of the filtrate in the liquid collecting tank, wherein the control unit is also used to control the discharge pump to open when the liquid level in the liquid collecting tank is higher than a first preset liquid level, so that the filtrate flows to the switch valve.

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

[0010] Optionally, when the liquid level meter monitors that the liquid level in the liquid collecting tank is continuously lower than a second preset liquid level for more than a set time, the control unit controls the filter press pump and the discharge pump to shut down, 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 transport the slurry to be filtered to the filter press.

[0011] On the other hand, an embodiment of the present invention provides a method for automatic circulation feeding of a filter press, wherein the filter press is used to receive slurry to be filtered and filter the slurry, the method comprising: detecting the turbidity of the filtrate pressed out by the filter press; and when the turbidity is greater than a set value, controlling a switch valve located in an outflow channel of the filtrate so that the filtrate flows back to the filter press to be filtered again.

[0012] Optionally, the switch valve includes a turbid liquid valve and a clear liquid valve, wherein opening of the turbid liquid valve allows the filtrate to flow back to the filter press, and opening of the clear liquid valve allows the filtrate to flow to a clear liquid tank, and controlling the switch valve located in the outflow channel of the filtrate so that the filtrate flows back to the filter press comprises: when the turbidity is greater than a set value, controlling the turbid liquid valve to open and the clear liquid valve to close, so that the filtrate flows back to the filter press for re-filtration.

[0013] Optionally, the method for automatic circulation feeding of the filter press also includes: monitoring the liquid level of the filtrate in the sump for receiving the filtrate pressed out of the filter press; and when the liquid level in the sump is higher than a first preset liquid level, controlling the discharge pump to open so that the filtrate flows to the switch valve, wherein the discharge pump is used to transport the filtrate in the sump to the switch valve.

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

[0015] Optionally, the method for automatic circulation feeding of the filter press also includes: when the liquid level of the sump is continuously lower than a second preset liquid level for more than a set time, controlling the filter press pump and the discharge pump to shut down, 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 the slurry to be filtered to the filter press.

[0016] Compared with the prior art, the present invention uses an online turbidity meter to detect the turbidity of the filtrate pressed out of the filter press, and controls the opening and closing of the switch valve through the control unit to realize the automatic switching of the turbid liquid circulation feeding and the clear liquid discharge. The equipment reduces manual operation, improves the automation degree of turbid liquid circulation filtration, and reduces occupational health risks and environmental risks. It is suitable for various types of filtering equipment with circulation filtration needs, such as ordinary plate-frame type, vertical type, box type, etc.

[0017] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0019] Figure 1 The present invention provides a system structure block diagram for automatic circulating feeding of a filter press.

[0020] Figure 2 It is a schematic diagram of a system for automatic circulating feeding of a filter press provided by an embodiment of the present invention.

[0021] Figure 3 The present invention is a flowchart of a method for automatic circulating feeding of a filter press provided by an embodiment of the present invention.

[0022] Description of Reference Numerals

[0023] 1 Feed tank 2 Filter press pump

[0024] 3 pressure gauge 4 filter press

[0025] 5 liquid collecting tank 6 liquid level gauge

[0026] 7 discharge pump 8 online turbidity meter

[0027] 9 turbid liquid valve 10 clear liquid valve

[0028] 11 Liquid tank DETAILED DESCRIPTION

[0029] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0030] Figure 1 : is a system structure diagram for automatic circulating feeding of a filter press provided by an embodiment of the present invention, such as Figure 1 As shown, the system for automatic circulating feeding of the filter press includes: a filter press 4, which is used to receive the slurry to be filtered and filter the slurry; an online turbidity meter 8, which is used to detect the turbidity of the filtrate pressed out by the filter press 4; a switch valve, which is located in the outflow channel of the filtrate; and a control unit, which is used to control the switch valve when the turbidity is greater than a set value, so that the filtrate flows back to the filter press 4 to be filtered again.

[0031] Optional, Figure 2 FIG. 1 is a schematic diagram of a system for automatic circulating feeding of a filter press provided by an embodiment of the present invention, see FIG. 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 to be filtered stored in the feed tank 1 is transported to the filter press 4, and the filter press 4 starts the filtration operation. Optionally, the turbidity setting value is preferably 0.5ntu, and the control unit is preferably a programmable logic controller (PLC). Figure 2 The pressure gauge 3 shown in FIG. 1 is used to monitor the feed pressure, and the switch valve includes Figure 2 The turbid liquid valve 9 and the clear liquid valve 10 are provided, wherein the turbid liquid valve 9 can be opened to allow the filtrate to flow back to the filter press 4, and the clear liquid valve 10 can be opened to allow 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 out by the filter press 4 is transported to the online turbidity meter 8, the online turbidity meter 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 into the feed tank 1 and is filtered again by the filter press 4.

[0033] See also Figure 2 The schematic diagram of the system for automatic circulating feeding of the filter press is shown, and the system for automatic circulating feeding of the filter press also includes: a liquid collecting tank 5, used to receive the filtrate pressed out by the filter press 4; a discharge pump 7, used to transport the filtrate in the liquid collecting tank 5 to the switch valve; and a liquid level meter 6, used to monitor the liquid level of the filtrate in the liquid collecting tank 5, wherein the control unit is also used to control the discharge pump 7 to open when the liquid level of the liquid collecting tank 5 is higher than a first preset liquid level, so that the filtrate flows to the switch valve.

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

[0035] like Figure 2 As shown, the liquid level meter 6 and the discharge pump 7 are interlocked. The liquid level meter 6 monitors the liquid level of the liquid collecting tank 5, and the PLC automatically adjusts the frequency of the discharge pump 7 according to the corresponding liquid level to maintain the liquid level of the liquid collecting tank 5 at a preset liquid level; when the liquid level meter 6 monitors that the liquid level of the liquid collecting 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.

[0036] Optionally, the preset liquid level is preferably 50% full liquid level, the second preset liquid level is preferably 20% full liquid level, and the set time is preferably 10s. Specifically, during the filter press operation, the liquid level meter 6 monitors the liquid level of the sump 5 at any time, and the PLC automatically adjusts the frequency of the discharge pump 7 according to the liquid level of the sump (5), thereby controlling the water outlet speed of the sump 5, so that the liquid level of the sump 5 is maintained at 50% full liquid level. When the liquid level meter 6 detects that the liquid level of the sump 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 this time, the PLC 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. Among them, when the PLC determines that the feed tank 1 is empty, it indicates that the solid-liquid separation work is completed, so the PLC is required 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, after the filter cake is formed, the online turbidity meter 8 detects that the turbidity of the filtrate is less than 0.5 ntu, the PLC controls the turbid liquid valve 9 to close and the clear liquid valve 10 to open, and the filtrate flows through the clear liquid valve 10 into the clear liquid tank 11 to achieve automatic collection of the clear liquid.

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

[0039] Figure 3 1 is a flow chart of a method for automatic circulating feeding of a filter press provided by an embodiment of the present invention. As shown in the figure, the method for automatic circulating feeding of a filter press includes:

[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 the switch valve in the outflow channel of the filtrate so that the filtrate flows back to the filter press 4 to be filtered again.

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

[0043] S40, when the liquid level of the liquid collecting tank 5 is higher than the first preset liquid level, control the discharge pump 7 to start, 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 liquid collecting tank 5 to maintain the liquid level of the liquid collecting tank 5 at a preset liquid level.

[0045] S60, when the liquid level of the liquid collecting tank 5 is continuously lower than the second preset liquid level for more than a set time, the filter press pump 2 and the discharge pump 7 are controlled to be turned off, and the filter press 4 is controlled 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.

[0046] The method for automatic circulating feeding of a filter press described above is similar to the embodiment of the system for automatic circulating feeding of a filter press described above, and will not be described in detail here.

[0047] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0048] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the 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), used for receiving the 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 switch valve is located in the outflow channel of the filtrate; as well as The control unit is used to control the switch valve when the turbidity is greater than a set value, so that the filtrate flows back to the filter press (4) to be filtered again.

2. The system for automatic circulating feeding of a filter press according to claim 1, characterized in that: The switch valve comprises a turbid liquid valve (9) and a clear liquid valve (10); when the turbidity is greater than a 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) to be filtered again; the turbid liquid valve (9) is opened to allow the filtrate to flow back to the filter press (4), and the clear liquid valve (10) is opened to allow 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 flows back to the filter press (4), the filtrate flows through a turbid liquid valve (9), a feed tank (1) and a filter press pump (2) in sequence, wherein 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 system also includes: A liquid collecting tank (5) for receiving the filtrate pressed out by the filter press (4); a discharge pump (7), used for conveying the filtrate in the liquid collecting tank (5) to the switch valve; and A liquid level meter (6) is used to monitor the liquid level of the filtrate in the liquid collecting tank (5). The control unit is further configured to control the discharge pump (7) to start when the liquid level in the liquid collecting tank (5) is higher than a first preset liquid level, so that the filtrate flows to the switch valve.

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

6. The system for automatic circulating feeding of a filter press according to claim 4, characterized in that: When the liquid level meter (6) detects that the liquid level of the liquid 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 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).

7. A method for automatic circulating feeding of a filter press, wherein the filter press (4) is used to receive slurry to be filtered and filter the slurry, characterized in that: The method includes: detecting the turbidity of the filtrate pressed out by the filter press (4); and When the turbidity is greater than a set value, the switch valve in the outflow channel of the filtrate is controlled so that the filtrate flows back to the filter press (4) to be filtered again.

8. The method for automatic circulating feeding of a filter press according to claim 7, characterized in that: The switch valve comprises a turbid liquid valve (9) and a clear liquid valve (10), wherein the turbid liquid valve (9) is opened to allow the filtrate to flow back to the filter press (4), and the clear liquid valve (10) is opened to allow the filtrate to flow to the clear liquid tank (11). The control of the switch valve in the outflow channel of the filtrate so that the filtrate flows back to the filter press (4) comprises: When the turbidity is greater than a set value, the turbid liquid valve (9) is controlled to open and the clear liquid valve (10) is controlled to close, so that the filtrate flows back to the filter press (4) to be filtered again.

9. The method for automatic circulating feeding of a filter press according to claim 7, characterized in that: The method further includes: monitoring the liquid level of the filtrate in the sump (5) for receiving the filtrate pressed out by the filter press (4); and When the liquid level in the liquid collecting tank (5) is higher than a first preset liquid level, the discharge pump (7) is controlled to open so that the filtrate flows to the switch valve, wherein the discharge pump (7) is used to transport the filtrate in the liquid collecting tank (5) to the switch valve.

10. The method for automatic circulating feeding of a filter press according to claim 9, characterized in that: The method further includes: The frequency of the discharge pump (7) is automatically adjusted according to the liquid level of the liquid collecting tank (5) to maintain the liquid level of the liquid collecting tank (5) at a preset liquid level.

11. The method for automatic circulating feeding of a filter press according to claim 9, characterized in that: The method further includes: When the liquid level of the liquid collecting tank (5) is continuously lower than a second preset liquid level for more than a set time, the filter press pump (2) and the discharge pump (7) are controlled to be turned off, and the filter press (4) is controlled 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).

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