Backwash liquid filter

Abstract

The utility model discloses a backwashing liquid filter which comprises a plurality of filter units and is characterized in that the filter units are connected in parallel for use, a feed pipe is connected in series between feed ports of the corresponding filter units, and a discharge pipe is connected in series between discharge ports of the filter units. A feed port and a discharge port of the filter unit are respectively provided with a liquid pressure sensor, a three-way ball valve is arranged between the feed pipe and the feed port of the filter unit, the three-way ball valve is provided with an electric actuator, and the electric actuator and the liquid pressure sensors are both connected with a PLC (Programmable Logic Controller) control system. And a manual stop valve is arranged between the discharge pipe and the discharge port of the filter unit. Automatic control is adopted, and backwashing of the filter is controlled through pressure feedback signals of an inlet and an outlet of the filter and PLC programming.

Description

Technical Field

[0001] The utility model relates to an improved invention of a liquid filter, in particular to an improved invention of a backwashing liquid filter. Background Art

[0002] In the field of liquid production, currently, when the pressure difference between the inlet and outlet of the filter reaches the allowable pressure difference, manual switching operation is still carried out. Since multiple liquid filters are used in parallel, the pre-filter pressure is generally above 1.0 MPa. The operation of the liquid filter is too frequent, and the manual switching operation for cleaning takes a long time cycle, which has an adverse impact on the production line, seriously reduces the production efficiency, increases the labor cost, and has certain potential safety hazards. Content of the Utility Model

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a backwashing liquid filter.

[0004] To solve the above technical problem, the utility model is implemented by the following technical solution: the backwashing liquid filter includes a number of filter units. It is characterized in that: the filter units are used in parallel, the feed ports of the corresponding filter units are connected in series with a feed pipe, and the discharge ports of the filter units are connected in series with a discharge pipe. Liquid pressure sensors are respectively arranged at the feed port and the discharge port of the filter unit. A three-way ball valve is arranged between the feed pipe and the feed port of the filter unit, and the three-way ball valve is equipped with an electric actuator. The electric actuator and the liquid pressure sensor are both connected to the PLC control system. A manual stop valve is arranged between the discharge pipe and the discharge port of the filter unit.

[0005] One end of the feed pipe is provided with a medium inlet, and a number of branch pipes communicating with the feed ports of the filter units are arranged on the feed pipe.

[0006] One end of the discharge pipe is provided with a medium outlet, and a number of branch pipes communicating with the discharge ports of the filter units are arranged on the discharge pipe.

[0007] The PLC control system is communicatively connected to the DCS system.

[0008] The beneficial effect of the utility model is that for the improved backwashing liquid filter, automatic control is adopted. The three-way ball valve at the feed port of the filter unit is driven by an electric actuator. Through the pressure feedback signal at the inlet and outlet of the filter and PLC programming, the backwashing of the filter is controlled. By opening the three-way ball valve, automatic backwashing of a single filter is realized; the PLC control system is communicatively connected to the DCS system, which can achieve precise, fast operation and remote communication control. Description of the Drawings

[0009] The following further elaborates on the specific implementation manners of the present utility model in conjunction with the accompanying drawings.

[0010] Figure 1 It is a schematic structural diagram of the present utility model.

[0011] Figure 2 It is a side view of the structure of the present utility model.

[0012] Figure 3 It is a top view of the structure of the present utility model. Specific implementation manners

[0013] The accompanying drawings show the structure of the present utility model. The following further explains its relevant details in conjunction with the accompanying drawings. In this embodiment, referring to the accompanying Figures 1 - 3 , the backwash liquid filter includes a number of filter units 1, and the filter units 1 are used in parallel. A feed pipe 3 is connected in series between the feed ports 2 of the corresponding filter units 1, and a discharge pipe 5 is connected in series between the discharge ports 4 of the filter units 1. Liquid pressure sensors are respectively provided at the feed port 2 and the discharge port 4 of the filter unit 1. A three-way ball valve 6 is provided between the feed pipe 3 and the feed port 2 of the filter unit 1. The three-way ball valve 6 is equipped with an electric actuator 7, and both the electric actuator 7 and the liquid pressure sensor are connected to the PLC control system. A manual stop valve 8 is provided between the discharge pipe 5 and the discharge port 4 of the filter unit 1. The manual stop valve 8 is normally in an open state and is reserved for emergency shutdown.

[0014] Regarding the backwash principle of the present utility model, when the pressure difference between the inlet and outlet of the filter unit 1 reaches the allowable pressure difference and the pre-filter pressure is above 1.0 MPa, the PLC control system obtains the inlet and outlet pressure signals fed back by the liquid pressure sensor, compares the set backwash conditions and backwash time. When the backwash adjustment is reached, it controls the electric actuator 7 to drive the three-way ball valve 6 to cut off the feed port 2 and the feed pipe 3, and switches to conduct the feed port 2 and the outside. The liquid flows reversely into the filter unit 1 through the discharge port 4 for backwashing. After the backwash duration reaches the set time, it is switched back to the conduction state of the feed port 2 and the feed pipe 3. The entire control process completely imitates the process of manual operation, but the accuracy and stability of the operation are much higher than that of manual execution.

[0015] As a further improved specific implementation manner, one end of the feed pipe 3 is provided with a medium inlet 9, and a number of branch pipes 10 communicating with the feed port 2 of the filter unit 1 are provided on the feed pipe 3.

[0016] As a further improved specific implementation manner, one end of the discharge pipe 5 is provided with a medium outlet 11, and a number of branch pipes 12 communicating with the discharge port 4 of the filter unit 1 are provided on the discharge pipe 5.

[0017] As a specific implementation of further improvement, the PLC control system is communicatively connected to the DCS system, enabling precise, fast operation and remote communication control.

[0018] In summary, the above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A backwash liquid filter, comprising a plurality of filter units, characterized in that: The filter units are used in parallel, a feed pipe is connected in series between the feed ports of the corresponding filter units, a discharge pipe is connected in series between the discharge ports of the filter units, the feed port and the discharge port of the filter unit are respectively provided with a liquid pressure sensor, a three-way ball valve is provided between the feed pipe and the feed port of the filter unit, the three-way ball valve is equipped with an electric actuator, the electric actuator and the liquid pressure sensor are both connected to the PLC control system, and a manual stop valve is provided between the discharge pipe and the discharge port of the filter unit.

2. The backwash liquid filter according to claim 1, characterized in that: One end of the feed pipe is provided with a medium inlet, and the feed pipe is provided with a plurality of branch pipes connected with the feed port of the filter unit.

3. The backwash liquid filter according to claim 1, characterized in that: One end of the discharge pipe is provided with a medium outlet, and the discharge pipe is provided with a plurality of branch pipes connected with the discharge port of the filter unit.

4. The backwash liquid filter according to claim 1, characterized in that: The PLC control system is communicatively connected with the DCS system.

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