Nitrogen Generator-Tianjin Newcen Technical Co.,Ltd.

The essence of nitrogen Fire Prevention is to inject the nitrogen to the mined-out oxidized area or fire zone, to reduce the content of oxygen to 7% or 3% or less to achieve the purpose of fire prevention. It has the functions of eliminating the risk of gas explosion; preventing the coal-heating and spontaneous combustion of the natural; reducing the combustion intensity, and preventing air leakage.

Nitrogen injection rate calculation:
In recent years, nitrogen injection has been identified as the primary measure in the fully-mechanized top coal caving mining method fire prevention. As a result of the geological structure differences of each mine and vary of coal mining conditions and external factors, the how to choose the nitrogen plant becomes much more difficult. In theory, the greater the flow of nitrogen injection is, (it is a special fire-fighting), the better the anti-fire effect will be, contrary to the worse, and even non-functional. To select equipment that meets the nitrogen anti-fire flow injection of nitrogen and can fully reflect the economic rationality of technology, in accordance with current more than 20 applications of nitrogen fire-fighting experience, we believe that the designing should focus on the following indicators:

1. Mined-out area inertia factors
The prevention of spontaneous combustion of coal, with an emphasis on inerting oxidation zone in the mined-out area， to make the oxygen content down to below the threshold of coal oxidation spontaneous combustion, to make the coal oxidation zone in an non oxidation or slow oxidation state. By the view of coal oxidation spontaneous combustion, the gas component in the mined-out area, except oxygen, the nitrogen, carbon dioxide and other inert gases can be considered to inhibit the oxidation of coal.
Oxygen is the improver to spontaneous combustion of coal. The consistency of oxygen in the mined out area reflects the effect of nitrogen injection. Therefore considering the critical value as indicators of inerting is reasonable. According to experimental results both home and abroad, when the oxygen content in the air is reduced to 7% ~ 10%, the coal is not susceptible to oxidation, so in the preparation for designing, 7% should be look as the basis indicator of mined out area inerting.

2. Fire zone inertia factors
Once the fire happens in the mine out area or roadway, the nitrogen injection should be large when adapting the nitrogen injection method. This is because that on the one hand, it should be inerting the fire space rapidly, on the other hand, injection of nitrogen would also inert the fresh airflow leaking in. After fire zone inerting, the continued injection of nitrogen major inert air leaking in, nitrogen flow should be on a corresponding reduction.
Experimental results show that: when oxygen gas content is less than 5%, the oxidation and combustion of coal can be negative. To prevent flammable gases from fire and explosion in mined out area, oxygen content should be below 3% for the design of inerting indicators

3. The calculation of mined out area nitrogen injection
For the different conditions of coal mining and no uniform formula to calculate, only can calculate by fully mechanized caving face (fully mechanized mining face) of the production, tons of coal nitrogen injection, gas volume, oxygen content within the oxidation zone.

 Coal use CMS nitrogen plant (Ground fixing and moving)
Since the large area of mining and frequency of fire, for the near distance between the ground surface and underground mine, Tianjin Newcen provide customers with the ground fixed, and mobile using carbon molecular sieve nitrogen mine devices.

This series nitrogen devices, the design layout has complete set the equipment on the skid bottom, the dimensions can meet the requirements of road and railway transportation, just a cable car can be fitted to the car to move to any of the mining area; through the power supply, water supply, pipelines connecting, the production of nitrogen will be able to boot, and implementation of nitrogen injection.

Features:
•The use of patented processes, compared with the same purity and flow of nitrogen, equipment energy consumption reduce 15-20%
•The use of user-friendly man-machine interface, intelligent control button for nitrogen production
•Unique compacting the carbon molecular sieve technology, high efficiency, long life; ease of installation, no special foundation, and the ground can be formed; high reliability, low running costs
•Low maintenance costs, local services, responsive and thoughtful appropriate