The working principle of nitrogen generator

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Next, Saiwei Fluid will introduce to you the working principle of the nitrogen generator. Let’s take a look.

Nitrogen generator is also called nitrogen machine. Nitrogen generator is a set of equipment that can extract nitrogen. Its main application fields are: petrochemical industry, electronic industry scientific experiments and other fields. In these fields, nitrogen generator plays an indispensable role. , Many chemical and other industries, raw material gas protection, etc. are inseparable from nitrogen. Next, Saiwei Fluid will introduce to you the working principle of the nitrogen generator. Let' s take a look.

There are three working principles of nitrogen generators:

1. Electrochemical nitrogen production

2. Membrane separation nitrogen production

3.PSA pressure swing adsorption nitrogen production.

Let me explain it in detail below.

1. Electrochemical nitrogen production

High-pressure air is introduced into the cathode (hydrogen-producing side) of the hydrogen electrolytic cell. Under the action of the catalyst, hydrogen and oxygen form a microscopic fuel cell, completing the oxidation-reduction reaction to produce water. The macroscopic manifestation is that the oxygen in the air is removed, and the remaining Nitrogen.

This method can produce 99.995% higher nitrogen, but has several obvious drawbacks:

① A high-concentration potassium hydroxide solution needs to be used as the electrolyte. This strong alkaline solution is in direct contact with the gas, which has a potential impact on the gas quality and may be output along the gas line;

② High unit cost;

③ The reaction process only removes oxygen in the air, and other impurity gases are not involved. Moreover, the reaction process requires high electrolytic cell manufacturing technology. Unsuitable electrolytic cell manufacturing technology will cause an order of magnitude reduction in nitrogen purity. As a low-flow nitrogen source, this type of nitrogen generator costs only a few thousand yuan in total. It is often used for chromatography carrier gas and small-volume protection, and is a low-cost solution.

2. Membrane separation nitrogen production

When high-pressure air passes through the hollow fiber membrane module, the difference in diffusion rates of nitrogen molecules and oxygen molecules accumulates. High-purity nitrogen is formed at the output end of the membrane module, and the purity of the formed product gas can reach as high as 99%. The gas flow rate is 5000ml/min, and it can be used cumulatively without affecting product quality. The gas installation can be expanded indefinitely without considering other constraints. This nitrogen production method, membrane separation nitrogen production, has many industrial applications. In laboratories, it is mainly used for purging, protection, and oxygen replacement that do not require particularly high gas purity.

The main advantage of this type of generator is its large flow rate. Laboratory-level products are generally around 50L/min and can be expanded at will. At the same time, it has a long life. As the core component, the membrane module can have a life of up to 10 years when the air source is stable, and the maintenance cost is extremely low. The disadvantage is that the purity of nitrogen cannot reach high-purity grade, the membrane components are currently imported and cannot be provided domestically, the cost is high, and the price of the instrument is relatively high.

3.PSA pressure swing adsorption nitrogen production

The difference in adsorption capacity between nitrogen and other gas molecules in the molecular sieve is used to accumulate concentration differences, and high-purity nitrogen is produced at the end of the molecular sieve column. At the same time, two molecular sieve columns are used. While one column is adsorbing, a part of the product gas is extracted for analysis by the other column to achieve online regeneration of the molecular sieve. The overall performance is that the instrument continuously outputs high-purity nitrogen.

This type of generator can adjust the purity and flow rate of nitrogen according to needs. It can produce up to 99.999% nitrogen products. The flow rate can range from hundreds of milliliters to tens of liters to several cubic meters per minute. The purity and size can be flexibly configured according to each need. For specific customization, the technical difficulty is mainly the molecular sieve column filling technology. Poor molecular sieve filling will cause the molecular sieves to rub against each other and pulverize during frequent changes in high and low pressure of the gas. The number of micropores will be reduced, and the performance of the molecular sieve will be drastically reduced.

PSA Nitrogen Generator

PSA Nitrogen Generator Supplier - Saiwei Fluid

Jiangsu Saiwei Fluid Technology Co., Ltd. is a supplier in the field of compressed gas, on-site nitrogen production and gas mixing system. It provides support and energy-saving services for diversified customer groups by providing reliable compressed gas and on-site nitrogen production system equipment.

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