Filter backwashing device

Abstract

The utility model provides a backwashing device of a filter. The backwashing device comprises a main pipe, a three-way electromagnetic valve, a differential pressure switch, a two-way electromagnetic valve and a bypass pipe, a three-way electromagnetic valve and a filter are respectively connected to the main pipe; the three-way electromagnetic valve comprises a first valve port, a second valve port and a third valve port, the first valve port and the second valve port are connected with an inlet of the main pipe and the filter respectively, the third valve port faces the air, the first valve port is communicated with the second valve port in a power-off state, and the second valve port is communicated with the third valve port in a power-on state; the differential pressure switch is connected to the two ends of the filter in parallel and used for enabling the three-way electromagnetic valve and the two-way electromagnetic valve to be synchronously switched between the power-off state and the power-on state. Two ends of the bypass pipe are connected to the main pipe in parallel; the two-way electromagnetic valve is installed on the bypass pipe, is in a normally-closed state when power is off and is in an open state when power is on. The device can monitor the blockage state of the filter screen of the filter and perform automatic backwashing, manual operation is not needed in the whole process, a water source does not need to be cut off during cleaning, and downstream water use is not affected.

Description

Technical Field

[0001] The utility model relates to the technical field of filtering devices, in particular to an automatic backwashing device for a filter. Background Art

[0002] A filter is a device commonly used in fluid pipelines to filter impurities in the medium and protect the normal operation of downstream equipment. Currently, commonly used filters include Y-type filters, T-type filters, basket filters, etc. These filters have simple structures and low prices, so they are widely used.

[0003] However, these filters all have a problem that their filter meshes are located in a closed cavity and cannot be directly observed from the outside. Once the filter mesh is blocked, it will cause a decrease in the pressure of the downstream pipeline and a reduction in the flow rate. For this reason, it is necessary to manually cut off the pipeline medium regularly and then disassemble, inspect and clean the filter mesh inside the filter. Since there are a large number of filters on different pipelines, the labor intensity of manual inspection and cleaning one by one is very high, and there may also be omissions. In addition, some special situations may occur during the interval between regular inspections, resulting in filter blockage. Due to the inability to monitor in real time, accidents are very likely to be triggered due to failure to clean in time. Summary of the Utility Model

[0004] In view of this, the utility model provides an automatic backwashing device for a filter to solve the technical problems that the labor intensity of manual inspection and cleaning one by one is very high, and some special situations may occur during the interval between regular inspections, resulting in filter blockage. Due to the inability to monitor in real time, accidents are very likely to be triggered due to failure to clean in time as described in the above background art.

[0005] The technical solution of the utility model is realized as follows:

[0006] The utility model provides an automatic backwashing device for a filter, which is used on the filter and includes a main pipe, a three-way solenoid valve, a differential pressure switch, a two-way solenoid valve and a bypass pipe. Among them:

[0007] The three-way solenoid valve and the filter are respectively connected to the main pipe.

[0008] The three-way solenoid valve includes a first valve port, a second valve port and a third valve port. The first valve port and the second valve port are respectively connected to the inlet of the main pipe and the filter; the third valve port is open to the air for draining water; when the three-way solenoid valve is in the power-off state, the first valve port and the second valve port are connected; when the three-way solenoid valve is in the power-on state, the second valve port and the third valve port are connected.

[0009] The differential pressure switch is connected in parallel at both ends of the filter and is used to synchronously switch the three-way solenoid valve and the two-way solenoid valve between the power-off and power-on states.

[0010] Both ends of the bypass pipe are connected in parallel to the main pipe, and the three-way solenoid valve and the filter are respectively located between two connection positions of the bypass pipe;

[0011] The two-way solenoid valve is installed on the bypass pipe and is normally closed when powered off and open when powered on.

[0012] Based on the above technical solutions, preferably, a differential pressure pipe is further included. Both ends of the differential pressure pipe are respectively connected to the inlet and outlet of the filter, and the differential pressure switch is installed on the differential pressure pipe.

[0013] Based on the above technical solutions, preferably, the differential pressure switch is in a normally open state, and the differential pressure switch can be switched to a conducting state when the differential pressure rises to reach a first preset threshold value.

[0014] Based on the above technical solutions, preferably, after backwashing for a certain period of time, the differential pressure switch can be switched to an off state when the differential pressure drops to reach a second preset threshold value, and the second preset threshold value is less than the first preset threshold value.

[0015] Based on the above technical solutions, preferably, the wiring port S1 of the two-way solenoid valve is connected to the negative pole of the power supply, the wiring port S2 of the two-way solenoid valve is connected to the wiring port P2 of the differential pressure switch, and the wiring port P1 of the differential pressure switch is connected to the positive pole of the power supply.

[0016] Based on the above technical solutions, preferably, the wiring port T1 of the three-way solenoid valve is connected to the negative pole of the power supply, the wiring port T2 of the three-way solenoid valve is connected to the wiring port P2 of the differential pressure switch, and the wiring port P1 of the differential pressure switch is connected to the positive pole of the power supply.

[0017] Based on the above technical solutions, preferably, both the two-way solenoid valve and the three-way solenoid valve are driven by a DC power supply.

[0018] Based on the above technical solutions, preferably, the two-way solenoid valve includes a coil and a spring, and the coil is used to provide magnetic attraction force when powered on;

[0019] When the coil is powered off, the elastic force of the spring closes the two-way solenoid valve;

[0020] When the coil is powered on, the magnetic attraction force provided by the coil is greater than the elastic force of the spring, so that the two-way solenoid valve is opened.

[0021] Based on the above technical solutions, preferably, in the power-off state of the three-way solenoid valve, the first valve port and the second valve port are communicated, and the third valve port is closed;

[0022] When the three-way solenoid valve is in the energized state, the second valve port and the third valve port are connected, and the first valve port is closed.

[0023] On the basis of the above technical solutions, preferably, the filter adopts a Y-type filter or a T-type filter.

[0024] The filter backwashing device of the present invention has the following beneficial effects compared with the prior art:

[0025] (1) When the filter is blocked to a certain extent, the differential pressure switch is turned on, so that the two-way solenoid valve is opened after being energized, the three-way solenoid valve is energized, the second valve port and the third valve port are connected, and the water entering from the inlet of the main pipe passes through the bypass pipe to backwash the filter, and then is discharged through the third valve port; this device can monitor the blocked state of the filter screen and perform automatic backwashing, without manual operation throughout the process, and the water source does not need to be cut off during cleaning, which will not affect the downstream water use, and has the characteristics of simple structure, high reliability, convenient installation, and low cost;

[0026] (2) The differential pressure switch is in the normally open state. When the filter screen of the filter is blocked and the differential pressure of the differential pressure switch rises to reach the first preset threshold, the differential pressure switch switches to the conducting state, so that the two-way solenoid valve and the three-way solenoid valve are energized to backwash the filter screen;

[0027] (3) After backwashing for a certain period of time, the differential pressure switch can switch to the off state when the differential pressure drops to reach the second preset threshold, and the second preset threshold is less than the first preset threshold. After the differential pressure switch is closed, the two-way solenoid valve and the three-way solenoid valve are de-energized, and the filter resumes normal operation. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0029] Figure 1 It is a structural diagram of the filter backwashing device of the present invention;

[0030] Figure 2 It is a principle flow chart of the filter backwashing device of the present invention when the filter is working normally;

[0031] Figure 3 It is a principle flow chart of the filter backwashing device of the present invention when backwashing the filter.

[0032] Description of reference numerals: 100 - filter, 1 - main pipe, 2 - three - way solenoid valve, 3 - differential pressure switch, 4 - two - way solenoid valve, 5 - bypass pipe, 6 - pressure difference pipe;

[0033] 21 - first valve port, 22 - second valve port, 23 - third valve port. Detailed implementation mode

[0034] Next, in combination with the implementation mode of the present utility model, the technical solutions in the implementation mode of the present utility model will be clearly and completely described. Obviously, the described implementation mode is only a part of the implementation modes of the present utility model, rather than all of the implementation modes. Based on the implementation modes in the present utility model, all other implementation modes obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present utility model.

[0035] Refer to Figures 1-3 As shown in the figure, an embodiment of the present utility model proposes a filter backwashing device for the filter 100, which includes a main pipe 1, a three - way solenoid valve 2, a differential pressure switch 3, a two - way solenoid valve 4 and a bypass pipe 5, wherein:

[0036] The three - way solenoid valve 2 and the filter 100 are respectively connected to the main pipe 1;

[0037] The three - way solenoid valve 2 includes a first valve port 21, a second valve port 22 and a third valve port 23. The first valve port 21 and the second valve port 22 are respectively connected to the inlet of the main pipe 1 and the filter 100; the third valve port 23 is open to the air for draining water; when the three - way solenoid valve 2 is in the power - off state, the first valve port 21 and the second valve port 22 are connected; when the three - way solenoid valve 2 is in the power - on state, the second valve port 22 and the third valve port 23 are connected;

[0038] The differential pressure switch 3 is connected in parallel at both ends of the filter 100, and is used to synchronously switch the three - way solenoid valve 2 and the two - way solenoid valve 4 between the power - off and power - on states; the differential pressure switch 3, also called a pressure difference switch, is composed of 2 diaphragm chambers. The two chambers are respectively sealed by two sealing diaphragms and a pressure - sensitive diaphragm. High pressure and low pressure respectively enter the high - pressure chamber and the low - pressure chamber of the differential pressure switch 3. The sensed pressure difference deforms the pressure - sensitive diaphragm, and through mechanical structures such as a railing spring, finally activates the micro - switch at the uppermost end to output an electrical signal;

[0039] Both ends of the bypass pipe 5 are connected in parallel to the main pipe 1, and the three - way solenoid valve 2 and the filter 100 are respectively located between the two connection positions of the bypass pipe 5;

[0040] The two - way solenoid valve 4 is installed on the bypass pipe 5, and is in a normally closed state when powered off and in an open state when powered on.

[0041] When the filter backwashing device provided by the embodiment of the present application is blocked to a certain extent, the differential pressure switch 3 is turned on, so that the two-way solenoid valve 4 is energized and opened, the three-way solenoid valve 2 is energized, the second valve port 22 and the third valve port 23 are communicated, and the water entering from the inlet of the main pipe 1 passes through the bypass pipe 5 to backwash the filter 100, and then is discharged through the third valve port 23; this device can monitor the clogging state of the filter screen of the filter 100 and perform automatic backwashing, without manual operation throughout the process, and the water source does not need to be cut off during cleaning, which will not affect the downstream water use. It has the characteristics of simple structure, high reliability, convenient installation and low cost.

[0042] In some embodiments, the filter backwashing device further includes a differential pressure pipe 6, both ends of the differential pressure pipe 6 are respectively connected to the inlet and outlet of the filter 100, and the differential pressure switch 3 is installed on the differential pressure pipe 6. By connecting both ends of the differential pressure pipe 6 to the inlet and outlet of the filter 100 respectively, and then installing the differential pressure switch 3 on the differential pressure pipe 6, it is convenient for the installation of the differential pressure switch 3, and the position of the differential pressure switch 3 can be adjusted arbitrarily, which is convenient for the flexible arrangement of the installation position of the differential pressure switch 3 and provides the convenience of the device.

[0043] In some embodiments, the differential pressure switch 3 is in a normally open state, and the differential pressure switch 3 can be switched to a conducting state when the differential pressure rises to reach a first preset threshold. By setting the differential pressure switch 3 to be in a normally open state, when the filter screen of the filter 100 is blocked and the differential pressure of the differential pressure switch 3 rises to reach the first preset threshold, the differential pressure switch 3 is switched to a conducting state, so that the two-way solenoid valve 4 and the three-way solenoid valve 2 are energized to backwash the filter screen of the filter 100. The first preset threshold can be set according to the actual situation of the use environment.

[0044] In some embodiments, after backwashing for a certain period of time, the differential pressure switch 3 can be switched to an off state when the differential pressure drops to reach a second preset threshold, and the second preset threshold is less than the first preset threshold. After backwashing for a certain period of time, after the filter screen is cleaned to a certain extent, when the differential pressure of the differential pressure switch 3 drops to reach the second preset threshold, it is switched to an off state, the two-way solenoid valve 4 and the three-way solenoid valve 2 are powered off, the two-way solenoid valve 4 is closed, and the water reaches the filter 100 from the first valve port 21 and the second valve port 22 of the three-way solenoid valve 2, and the filter 100 resumes normal operation to realize the filtering function.

[0045] In some embodiments, the wiring port S1 of the two-way solenoid valve 4 is connected to the negative pole of the power supply, the wiring port S2 of the two-way solenoid valve 4 is connected to the wiring port P2 of the differential pressure switch 3, and the wiring port P1 of the differential pressure switch 3 is connected to the positive pole of the power supply. Through the above circuit connection, the differential pressure switch 3 is connected in series to the circuit of the two-way solenoid valve 4, and the energization and de-energization of the two-way solenoid valve 4 are respectively realized by the conduction and closing of the differential pressure switch 3.

[0046] In some embodiments, the wiring port T1 of the three-way solenoid valve 2 is connected to the negative pole of the power supply, the wiring port T2 of the three-way solenoid valve 2 is connected to the wiring port P2 of the differential pressure switch 3, and the wiring port P1 of the differential pressure switch 3 is connected to the positive pole of the power supply. Through the above circuit connection, the differential pressure switch 3 is connected in series to the circuit of the three-way solenoid valve 2, and the energization and de-energization of the three-way solenoid valve 2 are respectively realized by the conduction and closing of the differential pressure switch 3.

[0047] In some embodiments, both the two-way solenoid valve 4 and the three-way solenoid valve 2 are driven by a DC power supply. It should be noted that the two-way solenoid valve 4 and the three-way solenoid valve 2 change their working states by energization and de-energization, which does not involve improvements in controllers and control methods.

[0048] In some embodiments, the two-way solenoid valve 4 includes a coil and a spring, and the coil is used to provide magnetic attraction when energized;

[0049] When the coil is de-energized, the elastic force of the spring closes the two-way solenoid valve 4;

[0050] When the coil is energized, the magnetic attraction provided by the coil is greater than the elastic force of the spring, opening the two-way solenoid valve 4.

[0051] In some embodiments, in the de-energized state of the three-way solenoid valve 2, the first valve port 21 and the second valve port 22 are connected, and the third valve port 23 is closed;

[0052] In the energized state of the three-way solenoid valve 2, the second valve port 22 and the third valve port 23 are connected, and the first valve port 21 is closed.

[0053] In some embodiments, the filter 100 is a Y-type filter 100 or a T-type filter 100. The filter 100 used in this embodiment is a conventional Y-type filter 100 or T-type filter 100, which has a wide range of applications and good applicability.

[0054] The working principle of this filter backwashing device is:

[0055] Normal state: As Figure 1 and Figure 2, when the filter 100 is not blocked, the pressure before and after the filter 100 is basically the same. The front-end pressure and the back-end pressure detected by the differential pressure switch 3 are basically the same, and the differential pressure switch 3 is in the off state. Therefore, both the two-way solenoid valve 4 and the three-way solenoid valve 2 are in the power-off state. At this time, the M port and the N port of the two-way solenoid valve 49 are in the off state, causing the bypass pipe 5 to be disconnected, and the A port and the C port of the three-way solenoid valve 2 are connected, and the B port is disconnected ( Figure 2 and Figure 3 In Figure 3 , the A port is the first valve port 21, the C port is the second valve port 22, and the B port is the third valve port 23). When the pressure medium enters from the inlet of the main pipe 1, it enters the filter 100 through the A port and the C port, and then flows out from the outlet of the main pipe 1. At this time, the filter 100 is in a normal working state, and the impurities in the medium can be intercepted at the filter screen;

[0056] Backwashing state: As Figure 1 and Figure 3 show, when too many impurities are intercepted by the filter screen and it becomes blocked, it will inevitably cause a decrease in the flow rate of the main pipe 1 and a decrease in the pressure at the outlet of the filter 100. At this time, the pressure difference detected by the differential pressure switch 3 will be relatively large, causing the differential pressure switch 3 to automatically close and conduct, and the two-way solenoid valve 4 and the three-way solenoid valve 2 are energized to change their working states. At this time, the M port and the N port of the two-way solenoid valve 4 are connected, causing the bypass pipe 5 to conduct. The A port of the three-way solenoid valve 2 is disconnected, and the B port and the C port are connected. When the pressure medium enters from the inlet of the main pipe 1, it flows through the bypass pipe 5 and the two-way solenoid valve 4 to the back end of the filter 100, and then flows reversely into the filter 100 from the back end to wash the filter screen inside. The washing water and impurities flow through the pipeline to the C port of the three-way solenoid valve 2. Since the C port and the B port are connected, the washing water and impurities are discharged from the B port outside the pipeline;

[0057] After a certain period of backwashing, the differential pressure switch 3 will automatically disconnect, and the two-way solenoid valve 4 and the three-way solenoid valve 2 will be de-energized and switched to the initial working state, and the pipeline will return to the normal working state, and the backwashing ends.

[0058] The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A filter backwashing device, used on a filter, characterized in that: It includes a main pipe, a three-way solenoid valve, a differential pressure switch, a two-way solenoid valve and a bypass pipe, of which: The main pipe is respectively connected to the three-way solenoid valve and the filter; The three-way solenoid valve comprises a first valve port, a second valve port and a third valve port, wherein the first valve port and the second valve port are respectively connected to the inlet of the main pipe and the filter; the third valve port is open to air for draining water; when the three-way solenoid valve is powered off, the first valve port is connected to the second valve port; when the three-way solenoid valve is powered on, the second valve port is connected to the third valve port; The differential pressure switch is connected in parallel to both ends of the filter, and is used to make the three-way solenoid valve and the two-way solenoid valve switch between the power-off state and the power-on state synchronously; The two ends of the bypass pipe are connected to the main pipe in parallel, and the three-way solenoid valve and the filter are respectively located between the two access positions of the bypass pipe; The two-way solenoid valve is installed on the bypass pipe, is in a normally closed state when the power is off, and is in an open state when the power is on.

2. The filter backwashing device according to claim 1, characterized in that: It also includes a pressure differential tube, both ends of which are respectively connected to the inlet and outlet of the filter, and the differential pressure switch is installed on the pressure differential tube.

3. The filter backwashing device according to claim 1, characterized in that: The differential pressure switch is in a normally open state, and can be switched to an on state when the pressure difference rises to reach a first preset threshold value.

4. The filter backwashing device according to claim 3, characterized in that: After backwashing for a certain period of time, the differential pressure switch can be switched to an off state when the pressure difference drops to a second preset threshold value, and the second preset threshold value is smaller than the first preset threshold value.

5. The filter backwashing device according to claim 4, characterized in that: The connection port S1 of the two-way solenoid valve is connected to the negative pole of the power supply, the connection port S2 of the two-way solenoid valve is connected to the connection port P2 of the differential pressure switch, and the connection port P1 of the differential pressure switch is connected to the positive pole of the power supply.

6. The filter backwashing device according to claim 5, characterized in that: The connection port T1 of the three-way solenoid valve is connected to the negative pole of the power supply, the connection port T2 of the three-way solenoid valve is connected to the connection port P2 of the differential pressure switch, and the connection port P1 of the differential pressure switch is connected to the positive pole of the power supply.

7. The filter backwashing device according to claim 1, characterized in that: The two-way solenoid valve and the three-way solenoid valve are both driven by a direct current power supply.

8. The filter backwashing device according to claim 7, characterized in that: The two-way solenoid valve comprises a coil and a spring, and the coil is used to provide magnetic attraction when energized; When the coil is powered off, the elastic force of the spring causes the two-way solenoid valve to close; When the coil is energized, the magnetic attraction force provided by the coil is greater than the elastic force of the spring, so that the two-way solenoid valve is opened.

9. The filter backwashing device according to claim 7, characterized in that: When the three-way solenoid valve is powered off, the first valve port and the second valve port are connected, and the third valve port is closed; When the three-way solenoid valve is powered on, the second valve port is connected to the third valve port, and the first valve port is closed.

10. The filter backwashing device according to any one of claims 1 to 9, characterized in that: The filter is a Y-type filter or a T-type filter.

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