Sweeping pump pressure control system

Abstract

The utility model discloses a pressure control system of a sweeping pump. The pressure control system comprises a control unit, a pressure transmitter, a digital display instrument and the sweeping pump, the sweeping pump is arranged in the sweeping pump pit, a probe of the pressure transmitter is arranged at the bottom of the sweeping pump pit, the digital display instrument is arranged outside the sweeping pump pit, and the pressure transmitter is electrically connected with the digital display instrument; the control unit comprises a stop button SB1, a relay normally open contact K1 output by a digital display instrument, a coil of an intermediate relay KA, a power-off delay normally closed contact of a time relay KT, a normally open contact of the intermediate relay KA, a coil of a pump contactor KM and a coil of the time relay KT. The device has the advantages that the problem that starting and stopping of the sweeping pump are affected due to aging and hardening of a floating ball line caused by long-time operation of a floating ball liquid level switch is solved, and the situation that when a probe of a pressure transmitter is only used for detecting the pressure lower limit value of liquid in a pit of the sweeping pump, a pressure lower limit signal is unstable is avoided; and the motor is burnt out due to frequent start and stop of the sweeping pump.

Description

Technical Field:

[0001] The utility model relates to the technical field of floor-sweeping pump control, and particularly relates to a floor-sweeping pump pressure control system. Background Art:

[0002] The floor-sweeping pumps in coal preparation plants are generally controlled by float level switches. The float level switch consists of structures such as a float, a gravity hammer, and a float wire. Its working principle is based on the buoyancy principle and magnetic action. When the liquid level in the floor-sweeping pump changes, the float will move up and down accordingly. The pump is started at a high liquid level and stopped at a low liquid level.

[0003] After long-term use, the float wire of the float level switch will become aged and hard, or there will be coal accumulation in the floor-sweeping pump pit, resulting in the float being unable to float or fall, thus affecting the start and stop of the floor-sweeping pump. The phenomenon of the floor-sweeping pump pit being flooded or the floor-sweeping pump being damaged due to long-term idling often occurs. Content of the Utility Model:

[0004] The purpose of the utility model is to provide a floor-sweeping pump pressure control system.

[0005] The purpose of the utility model is implemented by the following technical solution: A floor-sweeping pump pressure control system includes a control unit, a pressure transmitter, a digital display instrument, and a floor-sweeping pump; the floor-sweeping pump is arranged in the floor-sweeping pump pit, and the probe of the pressure transmitter is arranged at the bottom of the floor-sweeping pump pit. The digital display instrument is arranged outside the floor-sweeping pump pit, and the pressure transmitter is electrically connected to the digital display instrument;

[0006] The control unit includes a stop button SB1, a normally open contact K1 of a relay output by the digital display instrument, a coil of an intermediate relay KA, a normally closed contact of a power-off delay of a time relay KT, a normally open contact of the intermediate relay KA, a coil of a pump contactor KM, and a coil of the time relay KT;

[0007] The stop button SB1, the normally open contact K1 of the relay output by the digital display instrument, the coil of the intermediate relay KA, and the normally closed contact of the power-off delay of the time relay KT are connected in series between the power supply lines; the normally open contact of the intermediate relay KA is connected in parallel at both ends of the normally open contact K1 of the relay output by the digital display instrument. The coil of the time relay KT is connected in parallel at both ends of the coil of the intermediate relay KA, and the coil of the pump contactor KM is connected in parallel at both ends of the coil of the time relay KT.

[0008] Preferably, the control unit further includes a normally closed contact of a thermal relay FR, and the normally closed contact of the thermal relay FR is connected in series in the loop formed by the series connection of the stop button SB1, the normally open contact K1 of the relay output by the digital display instrument, the coil of the intermediate relay KA, and the normally closed contact of the power-off delay of the time relay KT.

[0009] Advantages of the present utility model: The present utility model is provided with a control unit, a pressure transmitter, a digital display instrument, an intermediate relay KA, a time relay KT, a pump contactor KM, and a floor sweeping pump; the floor sweeping pump is arranged in a floor sweeping pump pit, and the probe of the pressure transmitter is arranged at the bottom of the floor sweeping pump pit, and the digital display instrument is arranged outside the floor sweeping pump pit. The pressure transmitter is electrically connected to the digital display instrument. Using the present utility model to replace the float level switch not only solves the problem that the float wire ages and hardens after long-term operation of the float level switch, thus affecting the start and stop of the floor sweeping pump, but also avoids the problem that when simply using the probe of the pressure transmitter to detect the lower limit value of the liquid pressure in the floor sweeping pump pit, the lower limit pressure signal is unstable, resulting in frequent start and stop of the floor sweeping pump and burning out of the motor. Brief description of the drawings:

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model 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 drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0011] Figure 1 is a circuit schematic diagram of the control unit.

[0012] Figure 2 is a circuit schematic diagram of the main circuit controlled by the control unit.

[0013] Figure 3 is an installation state schematic diagram of the pressure transmitter, the digital display instrument, the floor sweeping pump and the floor sweeping pump pit.

[0014] The marks of each component in the drawings are as follows: pressure transmitter 1, digital display instrument 2, floor sweeping pump 3, floor sweeping pump pit 4, stop button SB1, normally open contact K1 of the relay output by the digital display instrument, intermediate relay KA, time relay KT, thermal relay FR, pump contactor KM, main switch QF, floor sweeping pump motor M. Detailed implementation manners:

[0015] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present utility model belong to the protection scope of the present utility model.

[0016] Such as Figures 1-3As shown in the figure, a pressure control system for a floor-sweeping pump includes a control unit, a pressure transmitter 1, a digital display instrument 2, and a floor-sweeping pump 3; the floor-sweeping pump 3 is arranged in a floor-sweeping pump pit 4, and the probe of the pressure transmitter 1 is arranged at the bottom of the floor-sweeping pump pit 4, and the digital display instrument 2 is arranged outside the floor-sweeping pump pit 4. The pressure transmitter 1 is electrically connected to the digital display instrument 2. The pressure transmitter 1 is a device for measuring liquid pressure, which converts the pressure into an electrical signal and outputs it to the digital display instrument 2. The probe of the pressure transmitter 1 is arranged at the bottom of the floor-sweeping pump pit 4, which can prevent the pressure value displayed on the digital display instrument 2 from being inaccurate due to the fluctuation of the water flow in the floor-sweeping pump pit 4;

[0017] The control unit includes a stop button SB1, a normally open contact K1 of a relay output by the digital display instrument 2, a coil of an intermediate relay KA, a normally closed contact of a power-off delay of a time relay KT, a normally closed contact of a thermal relay FR, a normally open contact of the intermediate relay KA, a coil of a pump contactor KM, and a coil of a time relay KT; the drainage time is set through the time relay KT to control the shutdown of the floor-sweeping pump 3, which can ensure the stable operation of the floor-sweeping pump 3. Compared with using the probe of the pressure transmitter 1 to detect the lower limit value of the liquid pressure in the floor-sweeping pump pit 4, using the time relay KT to time-control the shutdown of the floor-sweeping pump 3 is more accurate and stable; the reasons are as follows: since there is coal slime in the floor-sweeping pump pit 4, when using the probe of the pressure transmitter 1 to detect the lower limit value of the liquid pressure in the floor-sweeping pump pit 4, the lower limit pressure signal is often unstable, resulting in the situation that the floor-sweeping pump 3 starts and stops frequently and burns out the motor.

[0018] A stop button SB1, a normally open contact K1 of a relay output by the digital display instrument 2, a coil of an intermediate relay KA, a normally closed contact of a power-off delay of a time relay KT, and a normally closed contact of a thermal relay FR are connected in series between the power supply lines; a normally open contact of the intermediate relay KA is connected in parallel at both ends of the normally open contact K1 of the relay output by the digital display instrument 2, a coil of the time relay KT is connected in parallel at both ends of the coil of the intermediate relay KA, and a coil of the pump contactor KM is connected in parallel at both ends of the coil of the time relay KT.

[0019] The main circuit controlled by the control unit is of an existing structure, which includes a main switch QF, a normally open contact of the pump contactor KM, a coil of the thermal relay FR, and a floor-sweeping pump motor M; the main switch QF, the normally open contact of the pump contactor KM, the coil of the thermal relay FR, and the floor-sweeping pump motor M are connected in series to the three-phase power supply lines.

[0020] Working process: Fix the probe of the pressure transmitter 1 on an iron pipe and place it at the bottom of the floor-sweeping pump pit 4 to prevent the normally open contact K1 of the relay output on the digital display instrument 2 from malfunctioning due to the fluctuation of the water flow in the floor-sweeping pump pit 4. At this time, the probe of the pressure transmitter 1 can detect a 4-20ma pressure signal, transmit the pressure signal to the digital display instrument 2, and set it as the upper limit value of the pressure;

[0021] When the liquid in the floor sweeping pump pit 4 reaches the upper pressure limit, the normally open contact K1 of the relay output by the digital display instrument 2 is triggered to close. The coils of the intermediate relay KA, the time relay KT, and the pump contactor KM are simultaneously energized, and the floor sweeping pump 3 starts to drain water. The coil of the intermediate relay KA is instantaneously energized and attracted to drive the normally open contact of the intermediate relay KA to close, forming self-locking. The coil of the pump contactor KM is always energized, so even if the liquid in the floor sweeping pump pit 4 fluctuates and the pressure is unstable, it does not affect the stable drainage of the floor sweeping pump 3. At the same time, the coil of the time relay KT starts timing. After reaching the set time, the normally closed contact of the power-off delay of the time relay KT is disconnected, and the coils of the intermediate relay KA, the time relay KT, and the pump contactor KM are simultaneously de-energized, and the floor sweeping pump 3 automatically stops running.

[0022] The above are only the preferred embodiments of the present invention and are 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 sweeping pump pressure control system, characterized in that: It includes a control unit, a pressure transmitter, a digital display instrument and a sweeping pump; the sweeping pump is arranged in the sweeping pump pit, and the probe of the pressure transmitter is arranged at the bottom of the sweeping pump pit, the digital display instrument is arranged outside the sweeping pump pit, and the pressure transmitter is electrically connected to the digital display instrument; The control unit includes a stop button SB1, a relay normally open contact K1 output by a digital display instrument, an intermediate relay KA coil, a power-off delay normally closed contact of a time relay KT, a normally open contact of an intermediate relay KA, a pump contactor KM coil and a time relay KT coil; A stop button SB1, a normally open contact K1 of a digital instrument output relay, a coil of an intermediate relay KA and a normally closed contact of a time relay KT for power-off delay are connected in series between the power lines; the normally open contacts of an intermediate relay KA are connected in parallel at both ends of the normally open contact K1 of a digital instrument output relay, the coil of a time relay KT is connected in parallel at both ends of the coil of an intermediate relay KA, and the coil of a pump contactor KM is connected in parallel at both ends of the coil of a time relay KT.

2. A sweeping pump pressure control system according to claim 1, characterized in that: The control unit also includes a normally closed contact of a thermal relay FR, which is connected in series in a circuit consisting of a stop button SB1, a normally open contact K1 of a digital display output relay, an intermediate relay KA coil and a power-off delay normally closed contact of a time relay KT.

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