Nitrogen Generator for Coal Mine

Technology leader of Pressure Swing adsorption (PSA) nitrogen generator for coal mine.

Reliability from proprietary technology and years of experience

Technology leader of pressure swing adsorption (PSA) nitrogen generator for coal mine.

Reliability from proprietary technology and rich experience

In 1981, the vacuum desorption nitrogen generator developed by RICH passed the appraisal of Science and Technology Office of Shanghai Economic Commission and was widely applied in such industries as electronic, chemical engineering and metal heat treatment.

In 1996, RICH, together with Chongqing Research Institute of China Coal Technology & Engineering Group Corporation, developed and manufactured China's first underground use, horizontal type, mobile PSA nitrogen generator for coal mine, which was applied to Zhu Xian Zhuang coal mine of Huaibei mining bureau, Anhui Province and made RICH the first manufacturer that specialized in such type of product in China.

With 40 years' constant innovation and optimization in technology, energy-saving type PSA nitrogen generator manufactured by RICH has won high reputction all over the world, for its mature process and reliable performance.

New product adopts world first class carbon molecular sieve (CMS) and scientific RZ-VZ process guaranteeing maximum energy saving. Steadily reliable running of the equipment is guaranteed by its reliable air source treatment and multiple national patents.

China's first set of nitrogen generator(in 1981)


China's first set of underground-use mobile nitrogen generator(1996)

Certification of Safety

Trust coming from customer

RICH's PSA nitrogen generator for coal mine, with its reliable performance and efficiency in fire preventing & extinguishing, has won tremendous trust from customers. Here below are part of customers of RICH's PSA nitrogen generator for coal mine.

Underground-use Equipment

Equipment Functions

RICH provides DTJY series underground-use mobile nitrogen generator for coal mine that is wide and requires long N2 delivering pipe.

DTJY series nitrogen generator could be directly used underground. The whole system is mounted on flat bed trailers. Its dimensions (customized) could satisfy the requirements of elevator cage and underground tunnel transportation in coal mine.

Once a mining-out zone or other locations of working face shows the sign of catching fire, nitrogen generator could be lowered into mines and hauled close to the required fire preventing/extinguishing site by haulage motor. With the supply of electrical power, water and connection of piping, it could be started for N2 production and injection soon.

Equipment Specialities

1. Certified with National Safety Certificate of Approval for Mining Products, directly applicable for underground coal mine occasions with the existence of coal gas or firedamp.
2. Reasonable overall structure, fully workable for going underground and underground transportation.
The latest patent design of adsorption tower structure (Patent No. ZL97102764.1) ensures long life of CMS and equipment performance.
3. Unique design of horizontal adsorber head structure enables even distribution of gas flow and improves CMS efficiency.
4. The adopted Heatless-type, desiccant regenerating dryer pre-treatment and exhausted waste gas reutilization technology ensures reliable equipment performance and low running cost.
5. Track wheel type and Rubber wheel type structure in accordance with Coal Mine Track Standard and suitable for the passing requirements of class-5 road conditions.

Ground-Use Equipment

Equipment Functions

As for mines whose area is wide and of frequent fire or ground surface is close to underground working face, RICH provides ground-use, stationary-type or mobile nitrogen generator.

This series nitrogen generator is of skid-mounted design, whose dimensions are suitable for highway or railway transportation. It could be moved to anywhere within the mining area by simply using hoisting machine to lift it to a truck. With the supply of electrical power, water and connection of piping equipped, it could be started for N2 production and injection soon.

Equipment Specialities

1. Patent technical process adopted, 15~20% less energy consumption comparing to others at the same N2 purity and capacity. 
2. Humanized man-machine interface and intelligent control enables N2 production by simply pressing buttons.
3. National Patent CMS compacting technology, high efficiency, long life, simple installation without foundations as long as flat ground available.
4. High reliability and low running cost.
5. Low maintaining cost, site service enables fast and effective response.

Equipment Specialities
Normal configuration function

Online monitoring of nitrogen purity, pressure and flow

Man-machine operating system

Nitrogen sound and light alarm, long time alarm and automatic shutdown

Automatic reminder for replacement of wearing parts

Molecular sieve self-pressure

Pneumatic valve switching is automatically controlled by programmable controller

Automatic discharge of air conditioner and filter

Optional configuration feature

Automatic release of unqualified nitrogen

Adapt to the load

In the event of equipment failure, power outage or insufficient gas supply, a spare nitrogen automatic replenishment and automatic switching system should be adopted

In the event of equipment failure or power failure, the standby nitrogen automaticly switches system

Remote control/automatic (dedicated)

Automatic switch, stop/restart system for filling multiple tanks

Terminal gas recovery system (specific plan and configuration)

One machine can produce more than two kinds of different purity, corresponding to different flow automatic switching system

Specific configuration of industrial computer, DCS, other specific solutions

Technical Index

Underground-Use Equipment

N2 Capacity: 1~2000Nm3/h

N2 Pressure: 0.05~0.8MPa

N2 Purity:  97%、98%

Pressure dew point : ≤-40℃

Ground-Use Equipment

N2 Capacity:  100~4000Nm3/h

N2 Pressure:  0.05~0.8MPa

N2 Purity: 97%、98%

Pressure dew point : ≤-40℃


PSA(Pressure Swing Adsorption)is an advanced air separation technology.It remains an irreplaceable
standing in site gas supply field.

Under adsorption balance condition,for any adsorbent,when adsorbs one sort of gas,the higher the air pressure is,the more quantity it can adsorb,vice versa.

As shown on the diagram above,carbon molecular sieve has obvious adsorption differences to oxygen and nitrogen. There are many tiny holes inside the carbon molecular sieve.Under certain pressure,the tiny holes have different adsorption capacity to oxygen and nitrogen.When air pressure increases,carbon molecular sieve adsorbs oxygen and produces nitrogen,when air pressure drops to normal condition,carbon molecular sieve desorbs oxygen and regenerates itself.Two towers are generally provided,when one absorbs oxygen and produces nitrogen,the other desorbs oxygen and makes regeneration.This alternate process constantly produces nitrogen.

Components of Generator

Underground-Use Equipment

(1) Air Source Trailer
Mainly composed of air compressor, for providing compressed air with rated flow and pressure.

(2) Air Cleaning Trailer
Firstly, compressed air passes oil-removing purifier to have its most oil, water and dust removed. After that, it flows to fine filter, ultrafine filter, active carbon filter and active carbon oil-remover one after another for further removing of oil, water and dust. Finally, clean compressed air is obtained.

(3) Nitrogen Generation Trailer
Clean compressed air enters nitrogen generation system. By opening pipeline pneumatic valves, it flows into the two adsorption towers,filled with carbon molecular sieve (CMS) alternately with a certain pressure and time interval. In the adsorption towers, O2 molecule,smaller diameter, is adsorbed by CMS in priority while the N2 molecule whose diameter is bigger flows out of adsorption towers and is delivered via pipeline pneumatic valve. When tower A is being injected with air for adsorbing and producing N2,tower B is desorbing and discharging the adsorbed O2 for regenerating CMS. The so called course of desorption by discharging the adsorbed gases for CMS regeneration is realized as follows: By opening pipeline pneumatic valves, O2 adsorbed by CMS is discharged into atmosphere via muffler so as to pressure relieve CMS for its regeneration. In the mean time, part of the produced N2 gas flows back into adsorption tower that is desorbing via needle valve and check valve for purging purpose so as to improve CMS regeneration effect.

(4) Nitrogen Buffer Tank Trailer
N2 delivered from nitrogen generation trailer flows into nitrogen buffer tank. After having its dust removed by dedusting filter, its pressure and output flow are adjusted as needed by pressure regulating valve and throttle valve respectively. Meanwhile, a small part of N2 gas is delivered to CH4/O2 Analyzer via needle valve for O2 content inspection.


Ground-Use Equipment

(1) Compressed Air Cleaning Assembly
Compressed air from air compressor passes compressed air cleaning assembly first to have its most oil, water and dust removed by gas-water separator and pipeline filter and further processed by refrigerated dryer, fine filter and ultrafine filter. The specially designed oil remover protects carbon molecular sieve from even slight oil contamination, which ensures long life use of CMS. The clean compressed air after treatment could be used as instrument air.

(2) Air Tank Assembly
Air tank plays the role of buffering for the incoming clean air so as to reduce system pressure fluctuation and ensure stable pass of compressed air through compressed air cleaning package. It helps PSA O2/N2 Separation system relieve from heavy-load and when the two adsorption towers switch, it provides a huge amount of compressed air in a short time for fast pressure rise so that one tower's inside pressure reaches working pressure shortly and stable running of equipment is guaranteed.

(3) Oxyen And Nitrogen Separation Assembly
There are two adsorption towers (A and B) filled with CMS. When clean compressed air passes tower A, O2, CO2 and H2O are adsorbed while N2 gas flows out. After a period of time, adsorption of CMS in tower A is saturated and stops automatically. Compressed air then flows to Tower B for the same process and CMS in tower A is being regenerated. CMS regeneration is realized by fast reducing the pressure inside a tower to atmospheric pressure so as to desorb the O2, CO2 and H2O. Two towers' CMS adsorbs and regenerates alternately for continuous O2/N2 separation and N2 output. The above process is completely controlled by PLC. When gases are being exhausted to atmosphere, muffler helps reduce the noise to less than 85dBA.

(4) Nitrogen Buffer Tank Assembly
Nitrogen buffer tank is used for balancing the pressure and O2 content of N2 from PSA O2/N2 Separation System, so as to guarantee continuous and stable N2 supply. In addition, when the two adsorption towers switch, part of its N2 gas flows back to help raise pressure and protect their bed, which is an extremely important assistance for the technical process of the equipment.

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