How to choose a suitable nitrogen generator

Before determining the specific model specifications (i.e. Nitrogen Production per hour, nitrogen purity, outlet pressure, dew point), we should focus on a comprehensive comparative analysis of the performance and characteristics of thenitrogen generator, and make the right choice based on our existing environmental conditions.

Requirements for nitrogen in various industries

A, Metallurgy and metal processing industries

Some of these industries require nitrogen with a purity greater than 99.5%, while others require high-quality nitrogen with a purity greater than 99.9995% and a dew point lower than -65°C. This should be determined based on the customer's own production conditions.

B, Chemical and new materials industries

Generally, the requirements for nitrogen purity are not high, and many purities greater than 98% can be used. However, the actual requirements depend on the customer's own production process.

C, Food and pharmaceutical industries

Most food industries do not have high requirements for nitrogen, and 99.5%~99.9% purity can meet the requirements. A small number of food industries have to choose 99.99% purity due to process requirements. The pharmaceutical industry usually requires nitrogen purity of 99.99% and requires it to be made of stainless steel.

d Electronics industry

Generally, the requirements for nitrogen are relatively high, and usually a nitrogen purity of 99.99% or above is required.

Comparison between various Nitrogen Generators

A, Cryogenic air separation nitrogen generator

Cryogenic air separation nitrogen production is a traditional nitrogen production method with a history of nearly several decades. It uses air as raw material, compresses and purifies it, and then uses heat exchange to liquefy the air into liquid air. Liquid air is mainly a mixture of liquid oxygen and liquid nitrogen. The different boiling points of liquid oxygen and liquid nitrogen (at 1 atmosphere, the boiling point of the former is -183℃ and the latter is -196℃) are used to separate them through the distillation of liquid air to obtain nitrogen. Cryogenic air separation nitrogen production equipment is complex, occupies a large area, has high infrastructure costs, requires more one-time investment in equipment, has high operating costs, slow gas production (12 to 24 hours), has high installation requirements, and a long cycle. Considering the factors of equipment, installation and infrastructure, the investment scale of PSA equipment with the same specifications below 3500Nm3/h is 20% to 50% lower than that of cryogenic air separation equipment. Cryogenic air separation nitrogen production equipment is suitable for large-scale industrial nitrogen production, while medium and small-scale nitrogen production is not economical.

B, PSA pressure swing adsorption nitrogen generator

The method of using air as raw material, carbon molecular sieve as adsorbent, applying the principle of pressure swing adsorption, and using the selective adsorption of oxygen and nitrogen by carbon molecular sieve to separate nitrogen and oxygen is generally called PSA nitrogen production. This method is a new nitrogen production technology that developed rapidly in the 1970s. Compared with traditional nitrogen production methods, it has the characteristics of simple process flow, high degree of automation, fast gas production (15-30 minutes), low energy consumption, product purity can be adjusted within a large range according to user needs, convenient operation and maintenance, low operating cost, strong device adaptability, etc. Therefore, it is quite competitive in nitrogen production equipment below 1000Nm3/h, and is increasingly welcomed by medium and small nitrogen users. Psa Nitrogen production has become a method for medium and small nitrogen users.

C, Membrane separation nitrogen generator

Using air as raw material, under certain pressure conditions, oxygen and nitrogen are separated by using different permeation rates of gases with different properties such as oxygen and nitrogen in the membrane. Compared with other nitrogen production equipment, it has the advantages of simpler structure, smaller size, no switching valve, less maintenance, faster gas production (≤3 minutes), and convenient capacity expansion. It is particularly suitable for medium and small nitrogen users with nitrogen purity ≤98%, and has the best function-price ratio. When the nitrogen purity is above 98%, its price is more than 15% higher than that of PSA nitrogen generators of the same specifications.

Factors affecting the cost of nitrogen generators

1.One-time purchase cost of the entire system. At present, there are many brands in the market, and the quality is proportional to the price.

2.The stability of equipment operation and the estimated service life.

3.Annual operation and maintenance costs.

4.Daily water and electricity costs.