Coal Mine Nitrogen Gas N2 Nitrogen Generater
The combustion of coal is an oxidation process, and the prerequisite for coal combustion is sufficient oxygen. If the oxygen in the air does not reach the concentration required for coal combustion, then coal will not burn. Therefore, the oxygen concentration in the air can be reduced by injecting inert gas into the air to avoid coal combustion. The most common method of fire prevention in coal mines is to fill the coal mine with nitrogen, mainly because of its characteristics: colorless, tasteless, non-toxic, non-corrosive, very stable (especially under the action of vibration, heat and electric spark), simple production, low economic cost, and basically no pollution to the environment
The fire prevention function of filling nitrogen into the coal mine is mainly shown in:
(1) After filling the coal mine with nitrogen, the oxygen concentration in the goaf decreases; Nitrogen partially replaces oxygen to enter the coal fracture surface and exchange and adsorb with the micro surface of coal, thus reducing the adsorption amount of oxygen on the coal surface, and inhibiting or slowing down the oxidation of coal to a large extent.
(2) For the fire prevention by nitrogen injection in the fire prevention area with certain sealing conditions, after long-term and continuous filling of nitrogen into the coal mine, a large amount of nitrogen can form positive pressure in the goaf, thus reducing the amount of air leakage in the goaf, leaving the residual coal in an oxygen-deficient environment and not easy to oxidize.
(3) When nitrogen at a lower temperature flows through the coal body, it absorbs the heat generated by partial coal oxidation, which can slow down the rate of coal heating and reduce the temperature of surrounding medium, so that the oxidation of coal is delayed or terminated due to the destruction of heat accumulation conditions.
(4) After the combustible and explosive gas in the goaf is mixed with nitrogen, the explosion range gradually decreases with the increase of nitrogen concentration. When the mixture ratio of inert gas and combustible gas reaches a certain value, the upper and lower explosive limits of the mixture coincide, and the mixture loses its explosive capacity.
WORKING PRINCIPLE:
PSA technique (Pressure Swing Adsorption, PSA for short):it's a kind of advanced gas separation technology, based on physical adsorption of gas molecule on the internal surface of adsorbent (porous solid substances), using adsorbents in the same pressure easy to absorb the high boiling point gas, difficult to absorb low boiling point gas, and under high pressure adsorption amount of absorbed gas increases, under low pressure adsorption of absorbed gas to reduce the features to achieve gas separation. This process under pressure adsorption of impurities, under reduced pressure adsorption of impurities, make the adsorbent regeneration, is the PSA cycle.
