Underground coal mine mining explosion-proof and intrinsically-safe cooling drier control circuit

Abstract

The invention discloses an underground coal mine mining explosion-proof and intrinsically-safe cooling drier control circuit. The problems that a fan control circuit of an existing air cooling drier is unstable in voltage, and sparks and the heat effect easily occur are solved. The underground coal mine mining explosion-proof and intrinsically safe cooling drier control circuit comprises a transformer (15) transforming a 1140 V voltage to a 380 V voltage, an air circuit breaker fodder chopper switch (17), a cooling dryer contactor (18), a driving motor of a cooling dryer (19), a fan contactor (20), a fan driving motor (21), a normally open contact switch (23) of a guide circuit relay coil (14), a fan contactor control coil (22), a transformer (16) transforming a 220 V voltage into a 100 V voltage, and an intrinsically safe guide circuit (24). After optoelectronic isolation of a first photoelectric coupler (8), voltage bandwidth prefabrication of a voltage comparator, and second-stage optoelectronic isolation are conducted on the output of an intrinsically-safe filter voltage stabilizing circuit (3), an intrinsically-safe signal is output to an intrinsically-safe action switch (12). According to the underground coal mine mining explosion-proof and intrinsically-safe cooling drier control circuit, the service life of an underground nitrogen making machine is prolonged.

Description

technical field [0001] The invention relates to a control circuit of an explosion-proof and intrinsically safe cooling drier used in underground coal mines, which is suitable for use in conjunction with nitrogen generators under the condition of explosive mixed gas in underground coal mines. Background technique [0002] At present, the nitrogen generator used in underground coal mines is to produce nitrogen by separating the underground air through carbon molecular sieves for oxygen and nitrogen. Due to the high underground temperature and the high amount of impurities and moisture, the carbon molecular sieve is easily polluted and the service life of the nitrogen generator is shortened. The control circuit of the existing air-cooled dryer cannot be used in the underground where there is a danger of gas and coal dust. It cannot meet the requirements of the underground intrinsically safe control circuit, and it cannot be used in conjunction with the nitrogen generator. For ...

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Problems solved by technology

[0003] The invention provides a control circuit for an explosion-proof and intrinsically safe cooling drier used in underground coal mines, which solves the problem of large voltage fluctuations in the fan control circuit of the existing air-cooled drier, which easily generates sparks and accumulates thermal effects to cause detonation. technical problem

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