carbon molecular sieve,carbon molecular sieves,nitrongen gas
Directions in using CMS

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China Carbon Molecular Sieve Co, Ltd has been at the leading edge of Carbon Molecular Sieve Frontier in China since its establishment and CMS products have been exported to a number of countries and regions in Asia, America and Europe. The techniques for production of high quality CMS developed in our company have been awarded a number of prizes for contributions in science and technology by the National and the Provincial as well as the local administrations.

China Carbon Molecular Sieve Co, Ltd. will provide you and the new as well as old clients in nitrogen-making with our first-class brand and service.

The carbon molecular sieve (CMS)is a kind of? nonpolarity? sorbent. It has the performance to absorb oxygen in the air under changing pressure of normal temperature and acquire rich nitrogen gas through Pressure Swing Adsorption (PSA) process.

A. The Major Models of CMS
CMS-180 CMS-190 CMS-200 CMS-210 CMS-220

B. The Principle of producing nitrogen by CMS
A carbon molecular sieve belongs to the kind of carbon sorbent and it is the carbon skeletal flamework, which is a disordered accumulation of carbon. The capability of air separating is based on its skeletal framework. In dynamics, CMS has different adsorptive rate for oxygen and nitrogen. Under balanced condition , the adsorption by CMS towards O2 and N2 is very close, however, the speed O2 molecule passing through the framework is faster than N2 molecule, this principle is the bases of CMS N2 generation. Before the adsorption, oxygen and other impurities are adsorbed by the CMS, allowing unabsorbed nitrogen to pass through the bed.

C. Nitrogen generator by CMS
This apparatus is often called Air Separation Nitrogen Plants. The process uses the principle of Pressure Swing Adsorption(PSA).Pressure-swing adsorption nitrogen-making is realized through the features that CMS has, of selective adsorption and the difference adsorption capacity under different pressure. Oxygen molecular are withheld by carbon molecular sieve because its spreading speed is much quicker than nitrogen molecular in the carbon molecular sieve' minute hole structure when the pressure is raising, while the adsorption to nitrogen molecular are relieved by the oxygen gas. It makes carbon molecular sieve regenerate, forms circulatory operation, and realizes nitrogen-making continuously.

The PSA process includes; Pressure adding, Nitrogen producing, Pressure balancing; Pressure reducing, Nitrogen releasing; then repeat these procedures again,...and the circulation process was formed by these procedures .According to the style of regeneration, the process can be concluded into regelaeration in vacuum process (VPSA)and regeneration in normal pressure process.

According to the demands of clients, the nitrogen generation plant based on the PSA-process can consist into; the air pressing and purifying system, pressure swing and adsorption system, programmable valve controller system(the VPSA process even in need of the vacuum pump),and Nitrogen supply system.

D. The principle in controlling nitrogen generation by CMS

1.Air compressing and purifying process.

It is very necessary to let purified air into the adsorption tower, because if mote and organic gas entered the adsorptiorn tower, they will jam the skeletal framework, later it will lower the effects of generating.

The means to purify air; a. To keep the inlet of air compressing machine far away from dust, oil frog as well as organic gas; b. The raw material air, which pumped into the CMS adsorption tower, should first get through filter and cooler, also the purifying system filled with sorbent, later it will undergo a further transaction.

2.The N2 purity and production capacity.

When generation nitrogen by CMS, the N2 concentration and production capacity can be adjusted according to the needs of users. In a certain time and under a certain pressure, when reducing the production, the purity would rise; Otherwise, it would fall. User can adjust according to their practical needs.

3.The time period for pressure balancing.

In the process of generation, when one tower ends its adsorption, the compressed air can be immitted both from top and bottom into the other adsorption towers which had been regenerated, and then the two towers reach the same pressure, this process is called the pressure balancing between the two adsorption towers. If choosing a proper time for pressure balancing, it cannot only reclaim the energy, but also reducing the impingement CMS received, as a result, the purpose of prolonging the longevity of CMS is reached. With the reference to the speed of valve switching, the time for pressure balancing should be 1 to 3s.

4.N2 producing time period.

According to the fact that CMS have different rate in adsorption of N2 and it can saturate in a short time when adsorbing O2,while at the same time the amount of N2 adsorbed is small. The relatively short time period of nitrogen generation can also adds the frequency of valve switching, SO the performance of the valve is also very important. The normal time period of adsorption is 30 to 120s.Small-sized high purity N2 generator is recommended to have short period of generation time, while large-sized low purity generation long.

5.Operational Pressure

CMS has both the effect of dynamics and the effects of adsorption by depressurization. The capacity of adsorption raises when the pressure put on to the CMS is high, so adsorption by adding pressure is favorable, but the pressure adding demands higher model of air compressor.

Concerning adsorption pressure, the requirements in the process of normal pressure regeneration and vacuum generation is different. After considering an these conditions, the adsorption pressure under normal pressure is suggested to choose 5 to 8kg/cm2, vacuum 3 to 5kg/cm2.


As a sorbent, the relatively lower tempemture is good for the exertion of CMS. If possible, it is favorable for the nitrogen generator to lower the temperature of adsorption.

E. The package and usage of the product.

1.The products undergo strict check and measure in line with the standards of our company, so as to insure the quality of the product.

2.The products are airproofed in plastic barrels; the performance of hermetic package is reliable, open when padding into the generation towers, proof from moisture.

3.The padding should be tight, please make them tight and firm with proper method, don't pug it with a stick directly.


carbon molecular sieve,carbon molecular sieves,nitrongen gas
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