Introduction of Food Grade High Purity Nitrogen Generator / PSA Nitrogen System:
1. Classification of cryogenic air separation nitrogen, cryogenic air separation nitrogen is a traditional method of nitrogen production, has a history of recent decades. It uses air as raw material, compressed and purified, and then uses heat exchange to liquefy the air into liquid air. Liquid air is mainly a mixture of liquid oxygen and liquid nitrogen, using different boiling points of liquid oxygen and liquid nitrogen (at 1 atmosphere, the boiling point of the former is -183°C, and the temperature of the latter is -196°C). Separate them to obtain nitrogen. Low-temperature air separation nitrogen production equipment is complex, covers a large area, high infrastructure cost, large investment in one-time equipment, high operating cost, slow gas production (12-24 hours), high installation requirements, and long cycle. Comprehensive equipment, installation and infrastructure factors, for equipment less than 3500Nm3/h, the investment scale of the PSA unit of the same specification is 20% to 50% lower than that of the cryogenic air separation unit. Low-temperature air separation nitrogen production equipment is suitable for large-scale industrial nitrogen production, while small and medium-sized nitrogen production is uneconomical.
2. Molecular sieve air separation nitrogen production, using air as raw material, carbon molecular sieve as adsorbent, using the principle of pressure swing adsorption, through carbon molecular sieve selective adsorption of oxygen and nitrogen, nitrogen and oxygen are separated, commonly known as PSA nitrogen production. This method is a new nitrogen production technology developed rapidly in the 1970s. Compared with the traditional nitrogen production method, the process flow is simple, the degree of automation is high, the gas production speed is fast (15-30 minutes), the energy consumption is low, the product purity can be adjusted in a wide range according to user needs, and the operation is simple and easy to operate. The maintenance and operation of this equipment is low cost and highly adaptable, so it has considerable competitiveness in nitrogen production equipment below 1000Nm3/h, and is becoming more and more popular among small and medium-sized nitrogen users. PSA nitrogen production has become the choice of medium and small nitrogen users. method.
3. Nitrogen is produced by a membrane air separation method using air as a raw material, and uses gases with different properties (such as oxygen and nitrogen) with different permeation rates in the membrane under certain pressure conditions to separate oxygen and nitrogen. Compared with other nitrogen production equipment, it has the advantages of simple structure, small size, no switching valve, low maintenance, fast gas production (≤3 minutes), and convenient expansion. Especially suitable for small and medium-sized nitrogen users with nitrogen purity ≤98%. It has a good cost performance. When the purity of nitrogen is greater than 98%, it is more than 15% higher than the PSA nitrogen generator of the same specification.