Pump body protection control circuit

Abstract

A pump body protection control circuit comprises a nitrogen flow switch SQ1 and a cooling water pressure sensor SP1, and connection and disconnection of a pump body working relay KA1 are controlled through a high-voltage switch and a low-voltage switch of the nitrogen flow switch SQ1 and the cooling water pressure sensor SP1. And an auxiliary switch of the pump body working relay KA1 is used for judging whether the pump body M meets working conditions or not and controlling the work of the pump body M. A baffle type flow sensor adopted for cooling water protection is changed into an electric contact pressure gauge sensor, and electric self-locking control is added, so that potential safety hazards caused by long-time starting of the vacuum pump under the condition of no cooling water are avoided, and frequent starting / stopping of the vacuum pump is also avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial pump body control, in particular to a pump body protection control circuit. Background Art

[0002] In the current industrial pump field, piston / screw pumps are complete control equipment, and the manufacturer's equipment includes independent electrical control system cabinets. The above vacuum pump startup / operation has two conditions that must be met at the same time to ensure the normal operation of the equipment:

[0003] Condition 1: Nitrogen protection: Nitrogen is injected into the equipment cavity through the sensor to purge impurities in the cavity and ensure the replacement of flammable and explosive gases during the vacuum process;

[0004] Condition 2: Equipment cavity cooling water temperature reduction protection (referred to as cooling water protection): During the equipment vacuuming process, the internal mechanical components perform piston / screw compression movement, and the external circulating water enters the inlet / return interface device after passing through the sensor, and cooling measures are taken to protect the equipment.

[0005] However, the above-mentioned pump control has two defects: 1. Screw vacuum pump: This equipment uses a baffle-type flow sensor, which requires high-pressure circulating water to pass through in order to work properly. Due to the layout restrictions of the workshop, the vacuum pump is sometimes located on the roof, resulting in the pressure of the piston / screw vacuum pump circulating water use point on the roof can only be maintained at around 0.2Mpa, and may fluctuate with the use of other workshops or other work sections. As a result, the baffle-type water flow sensor of the vacuum pump cannot detect the signal, and it is mistakenly judged that there is no cooling water, and the vacuum pump automatically shuts down or cannot start normally; 2. Piston vacuum pump: The cooling water protection of this equipment is controlled by an electric contact pressure meter point. It is energized when it reaches the pressure contact and de-energized when it is lower than the pressure contact. For detailed control, see Figure 1 After the equipment is started, the vacuum pump starts and stops frequently due to vibration or fluctuations in circulating water pressure, which seriously affects the service life of the equipment. First, the frequent start and stop of the equipment seriously affects its service life, and second, the sudden lack of vacuum during production in the workshop brings safety hazards. Summary of the invention

[0006] The technical problem to be solved by the utility model is to provide a pump body protection control circuit, which can solve the control defects of the above-mentioned pump body.

[0007] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0008] A pump body protection control circuit includes a nitrogen flow switch SQ1 and a cooling water pressure sensor SP1. The high-pressure switch and the low-pressure switch of the nitrogen flow switch SQ1 and the cooling water pressure sensor SP1 are used to control the connection and disconnection of the pump body working relay KA1. The auxiliary switch of the pump body working relay KA1 is used to judge whether the pump body M meets the working conditions and control the operation of the pump body M.

[0009] The pump body M motor is electrically connected to the pump body contactor KM1, and the pump body contactor KM1 is electrically connected to the cooling pump power circuit breaker Q1.

[0010] The above-mentioned pump body contactor KM1 coil is controlled by the pump body control circuit.

[0011] The above-mentioned pump body control circuit includes a stop button SB1, a nitrogen flow switch SQ1, a pump body working relay KA1 normally open switch and a start button SB2 connected in series. The lower end of the start button SB2 is connected to the upper end of the pump body contactor KM1 coil, the upper end of the stop button SB1 and the lower end of the pump body contactor KM1 are respectively connected to the control power supply, and both ends of the stop button SB1 are connected in parallel with the pump body contactor KM1 normally open switch.

[0012] Both ends of the stop button SB1 are also connected in parallel with an automatic control switch.

[0013] The upper end of the coil of the above-mentioned pump body working relay KA1 is electrically connected to the normally closed switch of the pump body stop relay KA2, the upper end of the normally closed switch of the pump body stop relay KA2 is electrically connected to the high-pressure normally-open switch of the cooling water pressure sensor SP1, both ends of the high-pressure normally-open switch of the cooling water pressure sensor SP1 are connected in parallel with the normally-open switch of the pump body working relay KA1, and the lower end of the coil of the pump body working relay KA1 and the upper end of the high-pressure normally-open switch of the cooling water pressure sensor SP1 are electrically connected to the control power supply.

[0014] The upper end of the coil of the pump stop relay KA2 is electrically connected to the lower end of the low-pressure normally closed switch of the cooling water pressure sensor SP1, and the upper end of the low-pressure normally closed switch of the cooling water pressure sensor SP1 and the lower end of the coil of the pump stop relay KA2 are electrically connected to the control power supply.

[0015] The lower end of the normally open switch of the pump contactor KM1 is electrically connected to the pump operation indicator light L1, and the lower end of the pump operation indicator light L1 is connected to the control power supply.

[0016] The above-mentioned control power supply supplies power to the pump body control circuit through the control power circuit breaker Q2.

[0017] Both ends of the control power circuit breaker Q2 are connected to a power indicator light L2.

[0018] The utility model provides a pump body protection control circuit, which changes the baffle type flow sensor used for cooling water protection into an electric contact pressure gauge sensor and adds electrical self-locking control, thereby ensuring that the vacuum pump will not cause safety hazards by being turned on for a long time without cooling water, and also ensuring that the vacuum pump will not be frequently started / stopped. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0020] Figure 1 This is the existing pump control circuit diagram;

[0021] Figure 2 This is the pump body control circuit diagram of the utility model.

[0022] In the figure: cooling pump power circuit breaker Q1, control power circuit breaker Q2, control thermal protection relay FR, stop button SB1, start button SB2, nitrogen flow switch SQ1, cooling water pressure sensor SP1, pump body working relay KA1, pump body stop relay KA2, pump body contactor KM1, pump body M, pump body operation indicator light L1, power indicator light L2. DETAILED DESCRIPTION

[0023] like Figure 1-2 As shown in the figure, a pump body protection control circuit includes a nitrogen flow switch SQ1 and a cooling water pressure sensor SP1. The high-pressure switch and the low-pressure switch of the nitrogen flow switch SQ1 and the cooling water pressure sensor SP1 control the connection and disconnection of the pump body working relay KA1. The auxiliary switch of the pump body working relay KA1 is used to judge whether the pump body M meets the working conditions and control the operation of the pump body M.

[0024] The pump body M motor is electrically connected to the pump body contactor KM1, and the pump body contactor KM1 is electrically connected to the cooling pump power circuit breaker Q1.

[0025] The above-mentioned pump body contactor KM1 coil is controlled by the pump body control circuit.

[0026] The above-mentioned pump body control circuit includes a stop button SB1, a nitrogen flow switch SQ1, a pump body working relay KA1 normally open switch and a start button SB2 connected in series. The lower end of the start button SB2 is connected to the upper end of the pump body contactor KM1 coil, the upper end of the stop button SB1 and the lower end of the pump body contactor KM1 are respectively connected to the control power supply, and both ends of the stop button SB1 are connected in parallel with the pump body contactor KM1 normally open switch.

[0027] When the nitrogen flow reaches the set value of the nitrogen flow switch SQ1, the nitrogen flow switch SQ1 is closed. When the cooling water flow meets the starting conditions of the piston / screw vacuum pump, the cooling water pressure is within a specific value range, and the normally open switch of the pump working relay KA1 is closed. When these two conditions are met, the piston / screw vacuum pump meets the starting conditions and the pump contactor KM1 coil can be energized.

[0028] Both ends of the stop button SB1 are also connected in parallel with an automatic control switch.

[0029] The start and stop of the piston / screw vacuum pump can be controlled by command through the automatic control switch.

[0030] The upper end of the coil of the above-mentioned pump body working relay KA1 is electrically connected to the normally closed switch of the pump body stop relay KA2, the upper end of the normally closed switch of the pump body stop relay KA2 is electrically connected to the high-pressure normally-open switch of the cooling water pressure sensor SP1, both ends of the high-pressure normally-open switch of the cooling water pressure sensor SP1 are connected in parallel with the normally-open switch of the pump body working relay KA1, and the lower end of the coil of the pump body working relay KA1 and the upper end of the high-pressure normally-open switch of the cooling water pressure sensor SP1 are electrically connected to the control power supply.

[0031] When the cooling water flow reaches the starting condition of the piston / screw vacuum pump, the cooling water pressure exceeds the set value. At this time, the high-pressure normally open switch of the cooling water pressure sensor SP1 is closed, so that the normally open switch of the pump body working relay KA1 connected to the pump body contactor KM1 is closed, and the pump body meets the starting conditions. When the pump body stop relay KA2 is energized, the normally closed switch of the pump body stop relay KA2 is disconnected, the coil of the pump body working relay KA1 loses power, and the pump body does not meet the starting conditions.

[0032] The upper end of the coil of the pump stop relay KA2 is electrically connected to the lower end of the low-pressure normally closed switch of the cooling water pressure sensor SP1, and the upper end of the low-pressure normally closed switch of the cooling water pressure sensor SP1 and the lower end of the coil of the pump stop relay KA2 are electrically connected to the control power supply.

[0033] When the cooling water flow rate is lower than the minimum starting condition of the piston / screw vacuum pump, the cooling water pressure is lower than the minimum set value. At this time, the low-pressure normally closed switch of the cooling water pressure sensor SP1 is disconnected, the pump stop relay KA2 coil loses power, and the pump does not meet the starting conditions.

[0034] The lower end of the normally open switch of the pump contactor KM1 is electrically connected to the pump operation indicator light L1, and the lower end of the pump operation indicator light L1 is connected to the control power supply.

[0035] The above-mentioned control power supply supplies power to the pump body control circuit through the control power circuit breaker Q2.

[0036] Both ends of the control power circuit breaker Q2 are connected to a power indicator light L2.

[0037] Screw vacuum pump: Change the baffle flow sensor used for cooling water protection of the equipment to an electric contact pressure gauge sensor, and add electrical self-locking control, which is the same as the modification of the piston vacuum pump described below;

[0038] Piston vacuum pump: Utilize the original electric contact pressure gauge sensor, add electrical self-locking control, add a self-locking circuit in the control cabinet, and connect it through cables to ensure that the circulating water pressure can operate normally as long as it is 0.1-0.2Mpa. The pump can stop working when the water pressure reaches the low point or the water is cut off.

[0039] It not only ensures that the vacuum pump will not cause safety hazards by running for a long time without cooling water, but also ensures that the vacuum pump will not be started / stopped frequently.

[0040] In a preferred solution, an accumulator is added to the cooling pipeline, so that the cooling water flow rate or pressure can be maintained for a longer time.

Claims

1. A pump protection control circuit, characterized in that: It includes a nitrogen flow switch SQ1 and a cooling water pressure sensor SP1. The high-pressure switch and low-pressure switch of the nitrogen flow switch SQ1 and the cooling water pressure sensor SP1 control the connection and disconnection of the pump body working relay KA1. The auxiliary switch of the pump body working relay KA1 is used to judge whether the pump body M meets the working conditions and control the operation of the pump body M.

2. A pump protection control circuit according to claim 1, characterized in that: The pump body M motor is electrically connected to the pump body contactor KM1, and the pump body contactor KM1 is electrically connected to the cooling pump power circuit breaker Q1.

3. A pump protection control circuit according to claim 2, characterized in that: The pump contactor KM1 coil is controlled by the pump control circuit.

4. A pump protection control circuit according to claim 3, characterized in that: The pump body control circuit includes a stop button SB1, a nitrogen flow switch SQ1, a pump body working relay KA1 normally open switch and a start button SB2 connected in series. The lower end of the start button SB2 is connected to the upper end of the pump body contactor KM1 coil, the upper end of the stop button SB1 and the lower end of the pump body contactor KM1 are respectively connected to the control power supply, and both ends of the stop button SB1 are connected in parallel with the pump body contactor KM1 normally open switch.

5. A pump protection control circuit according to claim 4, characterized in that: The two ends of the stop button SB1 are also connected in parallel with automatic control switches.

6. A pump protection control circuit according to claim 4, characterized in that: The upper end of the coil of the pump body working relay KA1 is electrically connected to the normally closed switch of the pump body stop relay KA2, the upper end of the normally closed switch of the pump body stop relay KA2 is electrically connected to the high-pressure normally-open switch of the cooling water pressure sensor SP1, both ends of the high-pressure normally-open switch of the cooling water pressure sensor SP1 are connected in parallel with the normally-open switch of the pump body working relay KA1, and the lower end of the coil of the pump body working relay KA1 and the upper end of the high-pressure normally-open switch of the cooling water pressure sensor SP1 are electrically connected to the control power supply.

7. A pump protection control circuit according to claim 6, characterized in that: The upper end of the pump stop relay KA2 coil is electrically connected to the lower end of the low pressure normally closed switch of the cooling water pressure sensor SP1, and the upper end of the low pressure normally closed switch of the cooling water pressure sensor SP1 and the lower end of the pump stop relay KA2 coil are electrically connected to the control power supply.

8. A pump protection control circuit according to claim 7, characterized in that: The lower end of the normally open switch of the pump contactor KM1 is electrically connected to the pump operation indicator light L1, and the lower end of the pump operation indicator light L1 is connected to the control power supply.

9. A pump protection control circuit according to claim 8, characterized in that: The control power supply supplies power to the pump body control circuit through the control power circuit breaker Q2.

10. A pump protection control circuit according to claim 9, characterized in that: Both ends of the control power circuit breaker Q2 are connected to power indicator lights L2.

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