SU468013A1 - Control device of the spark test chamber - Google Patents

Description

one

The invention relates to devices for assessing the intrinsic safety of explosion-proof and mine electrical equipment for explosive rooms and coal mines.

The known control devices of the spark-testing chamber, comprising a contact block, an electric motor, a gas supply system, a purge valve with an actuator, an electromagnetic valve and a purge time relay, do not provide sufficient accuracy and reliability of operation.

The purpose of the invention is to improve the accuracy and reliability of the device.

For this purpose, in the proposed device, the intrinsically safe intermediate relay contacts are connected to the power supply circuit of the time relay, and the gas mixture supply delay relay, the contacts of which are included in the power supply circuit of the solenoid valve, is included in the operational time delay circuit.

The drawing shows a schematic diagram of the proposed device.

It has a contact block 1 connected to the gas-powered motor 2; it has a system, a purge valve with actuator 3, a solenoid valve 4, a purge time relay 5, an intrinsically safe intermediate relay 6, and a relay 7 for gas mixture delay.

A switch 8 serves to turn on the circuit. An electrical circuit to be tested for intrinsic safety is connected to the terminals of the contact block placed in the test chamber 9. The chamber also contains the contacts 10 of the control circuit of the intrinsically safe intermediate relay 6. The operational contacts 11 of this relay are included in the circuit powering the purge time relay 5. The contacts 12 of the relay 5 are included in the relay circuit 7 of the gas supply delay time, the time delay of which is controlled by the RC chain (13 and 14). Relay 7 contacts 5 controls the solenoid valve 4.

The relay 5 contacts 16 controls the purge valve 3, and the contacts 17 and 18 counters the number of sparks 19 and the number of explosions 20. The device operates as follows. When starting the motor with a switch

8, the contact block 1 is activated. Sparking at its contacts (with the corresponding parameters of the test circuit) causes an explosion in chamber 9. The explosion pressure in the chamber flips

a purge valve that closes the contacts 10 connected to the intrinsically safe intermediate relay 6. When the relay 6 is activated, its operational contacts AND close and the purge time relay 5 is turned on,

which, via contacts 12, activates a relay 7 for the delay in supplying the gas mixture, as a result of which for a few seconds it activates solenoid valve 4 with its contacts 13, which closes the gas supply system, stops the flow of gas mixture and thereby prevents the mixture from burning in the chamber.

After a predetermined period of time, the relay 7 will open the contacts 13, the solenoid valve 4 will open, the gas mixture will begin to flow into the chamber and blow it, the explosion products will be carried away. Through the camera’s purge time, the relay 5 closes the contacts 17 and 18 of the counters 19 and 20 and opens the contacts 16, closes the purge valve 3 and opens the contacts 10, causing the relay -6 to be de-energized, which contacts 11

opens the power circuit of relay 5, and the circuit returns to its original state.

Subject invention

The control device of the spark test chamber containing a contact block, an electric motor, a gas supply system, a purge valve with an actuator, an electromagnetic valve, a purge time relay, characterized in that, in order to increase the accuracy and reliability of operation, the purge time relay is included in the power supply circuit. contacts of an intrinsically safe intermediate relay; and a purge time delay relay is connected to the operational stump of the gas mixture supply delay relay, the contacts of which are included in the supply circuit of the electromagnetic valve.