Electric furnace circulating water pump control device

Abstract

The utility model provides a control device for a circulating water pump of an electric furnace, which belongs to the technical field of rock wool production and comprises a dual-power supply system, an alternating current contactor, an intermediate relay and a programmable logic controller (PLC). The dual-power supply system is connected with a coil of the alternating current contactor through a normally open contact of the intermediate relay, and the intermediate relay is connected with the PLC; and a change-over switch is connected in parallel between the normally open contact and the common end contact of the intermediate relay. The control of the PLC can be avoided, the circulating water pump is directly started, the operation of the circulating water pump in emergency is ensured, and the safety of the electric furnace is effectively ensured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to rock wool production technical field, especially relate to a control device for circulating water pump of electric furnace. BACKGROUND

[0002] Rock wool is made of high-quality basalt, dolomite and other materials, which is melted at a temperature above 1450 DEG C and then is spun into fibers by a four-axis centrifuge, and then a certain amount of binder, dustproof oil and water-repellent agent are sprayed into the fibers, and then the fibers are collected by a cotton collector and are solidified and cut after being laid by a three-dimensional method to form rock wool products of different specifications and purposes.

[0003] The temperature in the production process of electric furnace rock wool is very high, and the circulating water is needed to reduce the temperature, and the circulating water must be circulated throughout the process to ensure that the temperature of the electric furnace is controllable. Therefore, it is necessary to ensure the safe and reliable and stable operation of the circulating water pump.

[0004] In the prior art, the start and stop of the circulating water pump are controlled by a PLC controller, and when an emergency occurs, such as power failure or the PLC controller cannot work normally, the operation of the circulating water pump cannot be guaranteed, and thus the safety of the electric furnace cannot be guaranteed. UTILITY MODEL CONTENTS

[0005] In view of the defects or deficiencies in the prior art, the utility model provides a control device for circulating water pump of electric furnace, which can avoid the control of the PLC controller, directly start the circulating water pump, ensure the operation of the circulating water pump in an emergency, and effectively guarantee the safety of the electric furnace.

[0006] To achieve the above object, the utility model adopts the following technical scheme:

[0007] The embodiment of the utility model provides a control device for circulating water pump of electric furnace, which comprises a dual-power supply system, an AC contactor, an intermediate relay and a PLC controller, the dual-power supply system is connected with the circulating water pump through the AC contactor, the dual-power supply system is connected with the coil of the AC contactor through the normally open contact of the intermediate relay, and the intermediate relay is connected with the PLC controller.

[0008] The normally open contact of the intermediate relay is connected with the common terminal contact in parallel with a switch.

[0009] Further, the dual-power supply system is a three-phase power supply, and the three-phase power supply is connected with the input end of the main contact of the AC contactor.

[0010] Further, the output end of the main contact of the AC contactor is connected with the input end of the circulating water pump.

[0011] Further, one phase of the dual-power supply system is connected with the input end of the switch and the normally open contact of the intermediate relay. Further, the output end of the main contact of the AC contactor is connected with the input end of the circulating water pump.

[0012] Furthermore, the common terminal of the intermediate relay is connected to the output terminal of the switching switch and the coil A1 terminal of the AC contactor, respectively.

[0013] Furthermore, the A2 terminal of the AC contactor coil is connected to the neutral wire.

[0014] Furthermore, the intermediate relay coil is connected to the control terminal of the PLC controller.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] This invention connects a switching switch in parallel between the normally open contact and the common terminal contact of the intermediate relay. When a power outage occurs or the PLC malfunctions, the switching switch introduces one phase of the dual power supply system into the coil A1 terminal of the AC contactor, allowing the main contacts of the AC contactor to close normally. This bypasses the control of the PLC controller and the intermediate relay, enabling the circulating water pump to operate normally. Furthermore, the control methods in emergency situations and normal situations do not interfere with each other, thus ensuring the safety of the electric furnace. Attached Figure Description

[0017] Figure 1 This is a circuit diagram of the water pump control device in an embodiment of this utility model;

[0018] The components include: 1. Dual power supply system; 2. AC contactor; 3. Intermediate relay; 4. PLC controller; 5. Circulating water pump; and 6. Switch. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] A typical embodiment of this utility model is as follows: Figure 1 As shown, an electric furnace circulating water pump control device includes a dual power supply system 1, an AC contactor 2, an intermediate relay 3, and a PLC controller 4. The dual power supply system 1 uses two sets of power supplies, which can automatically switch to ensure power supply to the circulating water pump. This is existing technology and will not be described in detail here. The dual power supply system 1 is a three-phase power supply, namely phase A, phase B, and phase C. The three-phase power supply is connected to the input terminal of the main contact of the AC contactor 2, and the output terminal of the main contact of the AC contactor 2 is connected to the input terminal of the circulating water pump 5.

[0021] In the dual power supply system 1, one phase is also connected to the input terminal of the switching switch 6 and the normally open contact of the intermediate relay 3. In this embodiment, the C phase of the dual power supply system 1 is connected to the switching switch 6 and the intermediate relay 3. The common terminal contact of the intermediate relay 3 is connected to the output terminal of the switching switch 6 and the A1 terminal of the AC contactor 2 coil. The A2 terminal of the AC contactor 2 coil is connected to the neutral wire.

[0022] The switch 6 can be any switch capable of realizing line on-off, and in the embodiment, the switch 6 is a knob switch.

[0023] The coil of the intermediate relay 3 is connected with the control end of the PLC controller 4, so that the PLC controller 4 is used to control the coil of the intermediate relay 3 to be electrified.

[0024] In the normal state, the switch 6 is disconnected, and the whole system is powered by the dual-power supply system 1, when the PLC controller 4 sends a running instruction, the coil of the intermediate relay 3 is electrified, the normally open contact of the intermediate relay 3 is closed, the 220V alternating current from the C phase in the dual-power supply system 1 enters the A1 end of the coil of the alternating current contactor 2 through the intermediate relay 3, so that the main contact of the alternating current contactor 2 is closed, and the circulating water pump 5 is electrified to normally work.

[0025] When the PLC controller 4 sends a stop instruction, the normally open contact of the intermediate relay 3 is disconnected, the coil of the alternating current contactor 2 is de-energized, the main contact of the alternating current contactor 2 is disconnected, and the circulating water pump 5 is de-energized to stop running.

[0026] In the emergency state, the dual-power supply system 1 can still supply power through the diesel generator, but the PLC controller 4 cannot be used, at this time, the switch 6 is manually rotated to make the switch 6 in the closed state, the C phase in the dual-power supply system 1 is connected with the A1 end of the coil of the alternating current contactor 2, at this time, the 220V alternating current from the C phase in the dual-power supply system 1 directly enters the A1 end of the coil of the alternating current contactor 2 without passing through the intermediate relay 3, the coil of the alternating current contactor 2 is electrified, the main contact of the alternating current contactor 2 is closed, and the circulating water pump 5 is electrified to run.

[0027] When the system returns to normal, the coil of the intermediate relay 3 is electrified by the PLC controller 4, the normally open contact of the intermediate relay 3 is closed, at this time, the switch 6 is manually rotated to make the switch 6 closed, and the 220V alternating current can still enter the A1 end of the coil of the alternating current contactor 2, without affecting the running of the circulating water pump 5.

[0028] The utility model discloses a parallel switch between the normally open contact of the intermediate relay and the common end contact, when power failure and PLC cannot work normally, one phase in the dual-power supply system is introduced into the A1 end of the coil of the alternating current contactor through the switch, the main contact of the alternating current contactor is normally attracted, so that the PLC controller and the intermediate relay control are avoided, the normal running of the circulating water pump is realized, and the control mode in the emergency state and the control mode in the normal state do not interfere with each other, so that the safety of the electric furnace is ensured.

[0029] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A control device for an electric furnace circulating water pump, characterized in that, The double power supply system, the AC contactor, the intermediate relay and the PLC controller are connected, the double power supply system is connected with the circulating water pump through the AC contactor, the double power supply system is connected with the coil of the AC contactor through the normally open contact of the intermediate relay, and the intermediate relay is connected with the PLC controller; The normally open contact of the intermediate relay is connected with the common contact in parallel with the switch.

2. An electric furnace circulating water pump control device according to claim 1, wherein The double power supply system is a three-phase power supply, and the three-phase power supplies are connected with the input ends of the main contacts of the AC contactor.

3. An electric furnace circulating water pump control device according to claim 2, wherein The output end of the main contact of the AC contactor is connected with the input end of the circulating water pump.

4. An electric furnace circulating water pump control device as recited in claim 1, wherein, One phase of the double power supply system is connected with the input end of the switch and the normally open contact of the intermediate relay.

5. An electric furnace circulating water pump control device as set forth in claim 4, characterized by The common end of the intermediate relay is connected with the output end of the switch and the coil A1 end of the AC contactor.

6. An electric furnace circulating water pump control device as set forth in claim 5, characterized by The coil A2 end of the AC contactor is connected with the zero line.

7. An electric furnace circulating water pump control device as recited in claim 1, wherein, The coil of the intermediate relay is connected with the control end of the PLC controller.

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