A circulating water filter screen test device and method

Abstract

The present invention relates to the technical field of circulating water treatment, and specifically discloses a circulating water filter screen test device and method. A circulating water pump is provided at the inlet of the loop-shaped pipeline, and a test filter screen and a main pipeline flowmeter are provided on the loop-shaped pipeline; the outlet and the inlet of the test filter screen are connected through a pressure guiding pipeline, and a filter screen differential pressure gauge is provided on the pressure guiding pipeline; the sewage discharge port of the test filter screen is connected to a filter screen sewage discharge valve through a small-diameter pipeline, the outlet of the filter screen sewage discharge valve is provided with a sewage discharge pipeline flowmeter and is connected to a sewage pump, an impurity collector inlet valve, and an impurity collector in sequence through a small-diameter pipeline; the drainage main pipe of the impurity collector is communicated with the loop-shaped pipeline. The backwashing capacity test of the present invention can, on the basis of ensuring the effect of removing sundries, obtain a more optimal sewage discharge volume through tests and obtain the best sewage discharge efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of circulating water treatment, and particularly relates to a circulating water filter screen test device and method. Background Art

[0002] At present, the test device for the secondary filter screen of circulating water in China has a simple structure. Only the inlet and outlet of the filter screen are blocked by blind plates, and at the same time, the internal pressure of the filter screen cylinder is read through the pressure gauge on the blind plate to test the sealing performance of the filter screen. It can only perform equipment manufacturing quality verification such as factory water pressure test on the finished product of the secondary filter screen, and cannot complete relevant tests on the overall flow resistance, cleaning ability, etc. of the filter screen that reflect the equipment performance.

[0003] Therefore, there is an urgent need to design a circulating water filter screen test device and method to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a circulating water filter screen test device and method, which can test various performance indicators such as the flow resistance and dirt cleaning ability of the circulating water backwashing filter screen.

[0005] The technical solution of the present invention is as follows:

[0006] A circulating water filter screen test device includes a return pipeline, a circulating water pump, a test filter screen, a filter screen differential pressure gauge, a main pipeline flowmeter, a filter screen sewage discharge valve, a sewage pipeline flowmeter, a sewage pump, an impurity collector inlet valve, and an impurity collector;

[0007] A circulating water pump is provided at the inlet of the return pipeline, and a test filter screen and a main pipeline flowmeter are provided on the return pipeline;

[0008] The outlet and inlet of the test filter screen are connected through a pressure guiding pipeline, and a filter screen differential pressure gauge is provided on the pressure guiding pipeline;

[0009] The sewage outlet of the test filter screen is connected to the filter screen sewage discharge valve through a small-diameter pipeline. The outlet of the filter screen sewage discharge valve is provided with a sewage pipeline flowmeter and is connected to the sewage pump, the impurity collector inlet valve, and the impurity collector in sequence through a small-diameter pipeline;

[0010] The drainage main pipe of the impurity collector is connected to the return pipeline.

[0011] The impurity collector is of a cylindrical structure, and a mechanical filter screen is provided inside it. An inlet for water and an impurity outlet are respectively provided on the side wall of the impurity collector, and a clear water outlet is provided at the bottom of the impurity collector;

[0012] The clear water outlet and the impurity outlet are respectively connected to the drainage main pipe of the impurity collector.

[0013] An inlet and an impurity outlet are respectively provided above the side wall of the impurity collector, and both the inlet and the impurity outlet are higher than the upper edge of the mechanical filter screen.

[0014] The impurity discharge pipe passes through the impurity outlet on the impurity collector, one end extends into the bottom of the mechanical filter screen, and the other end is communicated with the drainage main pipe of the impurity collector.

[0015] An impurity release valve is provided on the impurity discharge pipe.

[0016] The clear water outlet is controlled by a clear water release valve.

[0017] The connection point between the drainage main pipe of the impurity collector and the return pipe is located on the pipe section between the inlet of the return pipe and the inlet of the test filter screen.

[0018] The clear water outlet is controlled by a clear water release valve;

[0019] The connection point between the drainage main pipe of the impurity collector and the return pipe is located on the pipe section between the inlet of the return pipe and the inlet of the test filter screen.

[0020] A circulating water filter screen test method based on the test device includes the following steps:

[0021] Step 1: Close the sewage pump and the impurity release valve, and open the filter screen sewage valve, the impurity collector inlet valve, the clear water release valve, and the circulating water pump;

[0022] Record the parameters P1 of the filter screen differential pressure gauge and the parameters Qv1 of the main pipeline flowmeter, and obtain the clean differential pressure (flow resistance) value P1 at different flow rates Qv1;

[0023] Step 2: Open the sewage pump, record the parameters Qv2 of the sewage pipe flowmeter, and confirm that the system can drain sewage normally;

[0024] Step 3: Close the sewage pump, the filter screen sewage valve, the circulating water pump, the impurity collector inlet valve, and the clear water release valve in sequence;

[0025] Step 4: Place sundries in the impurity collector, and open the impurity release valve and the impurity collector inlet valve;

[0026] Step 5: Open the circulating water pump, the filter screen sewage valve and the sewage pump and keep this state. The sundries are intercepted by the test filter screen, and record the parameter P2 until it is observed that the filter screen differential pressure gauge no longer changes;

[0027] Step 6: Close the impurity release valve and open the clear water release valve;

[0028] Step 7: Perform the backwashing of the test filter screen in cycle for n times, and record the parameters P3, P4,..., Pn+2 of the filter screen differential pressure gauge each time;

[0029] Until Pn+2 = P1, it indicates that all the debris on the test filter screen has been removed, and the backwashing ends.

[0030] Step 8: Organize the parameters recorded in Steps 1 to 7, and calculate the sewage discharge performance η of the test filter screen.

[0031] η = (P2 - Pn+2) / n (kpa / cycle).

[0032] The specific operation of the nth backwashing in Step 7 is as follows: Open the filter screen sewage discharge valve and the sewage pump, and keep them open for one backwashing cycle and then close them to remove the debris on the test filter screen. At this time, the backwashed impurities are collected by the impurity collector, and the parameter Pn+2 of the filter screen differential pressure gauge is recorded.

[0033] The remarkable effects of the present invention are as follows:

[0034] (1) The flow resistance test reflects the flow resistance of the filter screen under clean conditions. Different flow velocities reflect different pressure levels, and the clean differential pressure (water resistance) of the filter screen under different flow rates is measured by a variable-frequency circulating water pump.

[0035] (2) The backwashing ability test can obtain a more optimal sewage discharge volume through experiments on the basis of ensuring the debris removal effect, and obtain the best sewage discharge efficiency. Description of the Drawings

[0036] Figure 1 It is a schematic diagram of the test device.

[0037] In the figure: 1 - circulating water pump; 2 - test filter screen; 3 - filter screen differential pressure gauge; 4 - main pipeline flowmeter; 5 - filter screen sewage discharge valve; 6 - sewage pipeline flowmeter; 7 - sewage pump; 8 - impurity collector inlet valve; 9 - impurity collector; 10 - impurity release valve; 11 - clean water release valve. Detailed Embodiment

[0038] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0039] As Figure 1 shown, a circulating water filter screen test device includes a return pipeline, a circulating water pump 1, a test filter screen 2, a filter screen differential pressure gauge 3, a main pipeline flowmeter 4, a filter screen sewage discharge valve 5, a sewage pipeline flowmeter 6, a sewage pump 7, an impurity collector inlet valve 8, an impurity collector 9, an impurity release valve 10, and a clean water release valve 11.

[0040] A circulating water pump 1 is provided at the inlet of the return pipeline, and a test filter screen 2 and a main pipeline flowmeter 4 are provided on the return pipeline.

[0041] The outlet and inlet of the test filter screen 2 are connected through a pressure guiding pipeline, and a filter screen differential pressure gauge 3 is provided on the pressure guiding pipeline.

[0042] The sewage outlet of the test filter screen 2 is connected to the filter screen sewage discharge valve 5 through a small-diameter pipeline. A sewage discharge pipe flowmeter 6 is arranged at the outlet of the filter screen sewage discharge valve 5 and is sequentially connected to a sewage pump 7, an impurity collector inlet valve 8, and an impurity collector 9 through a small-diameter pipeline.

[0043] The impurity collector 9 has a cylindrical structure, and a mechanical filter screen is arranged inside it. An inlet and an impurity outlet are respectively arranged above the side wall of the impurity collector 9. Both the inlet and the impurity outlet are higher than the upper edge of the mechanical filter screen. A clear water outlet is arranged at the bottom of the impurity collector 9. The clear water outlet is controlled by a clear water release valve 11 and is communicated with the drainage main pipe of the impurity collector 9.

[0044] The impurity discharge pipe passes through the impurity outlet on the impurity collector 9, one end extends into the bottom of the mechanical filter screen, and the other end is communicated with the drainage main pipe of the impurity collector 9. An impurity release valve 10 is arranged on the impurity discharge pipe.

[0045] The drainage main pipe of the impurity collector 9 is communicated with a return pipe, and the connection point is located on the pipe section between the inlet of the return pipe and the inlet of the test filter screen 2.

[0046] A circulating water filter screen test method, which is operated by using the above test device, includes the following steps:

[0047] Step 1: Close the sewage pump 7 and the impurity release valve 10, and open the filter screen sewage discharge valve 5, the impurity collector inlet valve 8, the clear water release valve 11, and the circulating water pump 1;

[0048] Record the parameter P1 of the filter screen differential pressure gauge 3 and the parameter Qv1 of the main pipeline flowmeter 4 to obtain the clean differential pressure flow resistance value P1 at different flow rates Qv1;

[0049] Step 2: Open the sewage pump 7, record the parameter Qv2 of the sewage discharge pipe flowmeter 6, and confirm that the system can discharge sewage normally;

[0050] Step 3: Close the sewage pump 7, the filter screen sewage discharge valve 5, the circulating water pump 1, the impurity collector inlet valve 8, and the clear water release valve 11 in sequence;

[0051] Step 4: Place sundries in the impurity collector 9, and open the impurity release valve 10 and the impurity collector inlet valve 8;

[0052] Step 5: After opening the circulating water pump 1, the filter screen sewage discharge valve 5, and the sewage pump 7, keep this state. The sundries are intercepted by the test filter screen 2 until the parameter P2 is recorded when it is observed that the display of the filter screen differential pressure gauge 3 no longer changes;

[0053] Step 6: Close the impurity release valve 10 and open the clear water release valve 11;

[0054] Step 7: Perform backwashing of the test filter screen 2. The specific operation is as follows:

[0055] Open the filter screen drain valve 5 and the drain pump 7 and close them after a continuous backwashing cycle to remove the debris on the surface of the test filter screen 2. At this time, the flushed impurities are collected by the impurity collector 9, and the parameter Pn+2 of the filter screen differential pressure gauge 3 is recorded; the said one backwashing cycle is a certain period of time, such as 60 s;

[0056] Perform the backwashing of the test filter screen 2 in cycle for n times, and record the parameters P3, P4, …, Pn+2 of the filter screen differential pressure gauge 3 each time until Pn+2 = P1, which indicates that all the debris on the surface of the test filter screen 2 has been removed, and the backwashing is ended;

[0057] Step 8: Sort out the parameters recorded in Steps 1 to 7, and calculate the drain performance η of the test filter screen 2;

[0058] η = (P2 - Pn+2) / n (kpa / cycle).

[0059] Embodiment

[0060] For the flow resistance test of a certain filter screen, it can be directly read by the on-site instrument, and it can be known that the clean differential pressure (flow resistance) P1 of the filter screen under the Qv1 flow condition. The test data examples are as follows:

[0061] Cleaning differential pressure (flow resistance) P1 Qv1 12.1 kpa <![CDATA[2258m 3 / h]]> 10.8 kpa <![CDATA[1784m 3 / h]]>

[0062] The calculation formula for the drain performance test of the filter screen is η = (P2 - P3) / n (kpa / cycle),

[0063] Filter screen sewage discharge performance η P2 P3 n Qv1 Qv2 106.8 kpa / cycle 119.4 kpa 12.6 kpa 1 <![CDATA[2220m 3 / h]]> <![CDATA[59m 3 / h]]> 200.5 kpa / cycle 215.3 kpa 14.8 kpa 1 <![CDATA[2232m 3 / h]]> <![CDATA[50m 3 / h]]> 76.3 kpa / cycle 86.4 kpa 10.1 kpa 1 <![CDATA[2232m 3 / h]]> <![CDATA[50m 3 / h]]> 106.8 kpa / cycle 117.9 kpa 11.1 kpa 1 <![CDATA[2238m 3 / h]]> <![CDATA[46m 3 / h]]> .

[0064] The above is only the preferred embodiment of the present invention, and is not used to limit the scope of implementation of the present invention. All equivalent changes and modifications made according to the shape, structure, features and spirit described in the scope of the claims of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A circulating water filter screen test device, characterized in that: it includes a loop-shaped pipeline, a circulating water pump (1), a test filter screen (2), a filter screen differential pressure gauge (3), a main pipeline flowmeter (4), a filter screen blowdown valve (5), a blowdown pipeline flowmeter (6), a blowdown pump (7), an impurity collector inlet valve (8), and an impurity collector (9); A circulating water pump (1) is provided at the inlet of the loop-shaped pipeline, and a test filter screen (2) and a main pipeline flowmeter (4) are provided on the loop-shaped pipeline; The outlet and inlet of the test filter screen (2) are connected through a pressure guiding pipeline, and a filter screen differential pressure gauge (3) is provided on the pressure guiding pipeline; The blowdown port of the test filter screen (2) is connected to the filter screen blowdown valve (5) through a small-diameter pipeline, and the outlet of the filter screen blowdown valve (5) is provided with a blowdown pipeline flowmeter (6) and is connected to the blowdown pump (7), the impurity collector inlet valve (8), and the impurity collector (9) in sequence through a small-diameter pipeline; The drainage main pipe of the impurity collector (9) is communicated with the loop-shaped pipeline; The impurity collector (9) is of a cylindrical structure, and a mechanical filter screen is provided inside it. An inlet and an impurity outlet are respectively provided on the side wall of the impurity collector (9), and a clear water outlet is provided at the bottom of the impurity collector (9); The clear water outlet and the impurity outlet are respectively communicated with the drainage main pipe of the impurity collector (9); The impurity discharge pipe passes through the impurity outlet on the impurity collector (9), one end extends into the bottom of the mechanical filter screen, and the other end is communicated with the drainage main pipe of the impurity collector (9); An impurity release valve (10) is provided on the impurity discharge pipe; The clear water outlet is controlled by a clear water release valve (11); The connection part of the drainage main pipe of the impurity collector (9) and the loop-shaped pipeline is located on the pipe section between the inlet of the loop-shaped pipeline and the inlet of the test filter screen (2).

2. A circulating water filter screen test device according to claim 1, characterized in that: An inlet and an impurity outlet are respectively provided above the side wall of the impurity collector (9), and both the inlet and the impurity outlet are higher than the upper edge of the mechanical filter screen.

3. A circulating water filter screen test method based on the test device according to claim 2, characterized in that: it includes the following steps: Step 1: Close the blowdown pump (7) and the impurity release valve (10), and open the filter screen blowdown valve (5), the impurity collector inlet valve (8), the clear water release valve (11), and the circulating water pump (1); Record the parameter P1 of the filter screen differential pressure gauge (3) and the parameter Qv1 of the main pipeline flowmeter (4) to obtain the clean differential pressure value P1 at different flow rates Qv1; Step 2: Open the blowdown pump (7), record the parameter Qv2 of the blowdown pipeline flowmeter (6), and confirm that the system can discharge sewage normally; Step 3: Close the blowdown pump (7), the filter screen blowdown valve (5), the circulating water pump (1), the impurity collector inlet valve (8), and the clear water release valve (11) in sequence; Step 4: Place sundries in the impurity collector (9), and open the impurity release valve (10) and the impurity collector inlet valve (8); Step 5: Keep the state after turning on the circulating water pump (1), the filter screen blowdown valve (5) and the sewage pump (7). Debris is intercepted by the test filter screen (2) until the parameter P2 is recorded when it is observed that the filter screen differential pressure gauge (3) shows no further change. Step 6: Close the impurity release valve (10) and open the clean water release valve (11). Step 7: Perform the backwashing of the test filter screen (2) in cycles for n times, and record the parameters P3, P4, …, Pn+2 of the filter screen differential pressure gauge (3) each time. Until Pn+2 = P1, it indicates that all the debris on the surface of the test filter screen (2) has been removed, and the backwashing is ended. Step 8: Organize the parameters recorded in Steps 1 to 7 and calculate the sewage discharge performance η of the test filter screen (2). η = (P2 - Pn+2) / n (kpa / cycle).

4. A circulating water filter screen test method according to claim 3, characterized in that: The specific operation of the nth backwashing in Step 7 is: Open the filter screen blowdown valve (5) and the sewage pump (7) and keep them open for one backwashing cycle and then close them to remove the debris on the surface of the test filter screen (2). At this time, the backwashed impurities are collected by the impurity collector (9), and the parameter Pn+2 of the filter screen differential pressure gauge (3) is recorded.

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