Air separation plant is to use air as raw material, through the compression cycle deep freezing method to turn air into liquid, and then through rectification and gradually separate from the liquid air to produce oxygen, nitrogen and argon and other inert gases equipment.
Air separation equipment manufacturer
Gas separation equipment refers to the gas liquefaction, rectification, and final separation into oxygen, nitrogen and other useful gases equipment. Gas separation equipment is a complete set of equipment composed of a variety of machinery and equipment, often classified according to air pressure. Commonly used are high pressure, medium pressure and low pressure 3.
When selecting the type of equipment, the requirements of product type, demand and purity should be considered, as well as power consumption, safe continuous operation cycle and other factors.
Low pressure gas equipment is widely used because of its low power consumption, long continuous operation cycle and high economic benefit.
Cryogenic equipment for separating single-component gaseous and liquid products from multi-component feedstock gas. Multi-component raw gas usually refers to air, natural gas, coke oven gas, water gas, ammonia release gas and various cracking gas. Common gas separation equipment includes air separation equipment, natural gas separation equipment, synthetic ammonia release gas separation equipment, coke oven gas, water gas separation equipment and rare gas extraction equipment.
Principle of gas separation
The basic principle of separation is: the purified raw gas with pressure or pressure is cooled step by step to the condensation temperature of each separated component for separation (single stage or step by step condensation); Or the raw material gas is separated by pressurization, cooling, liquefaction and rectifying. Common gas condensation temperature (at 101.325 kpa pressure)
At present, there are many forms and types of air separation equipment produced. There are devices for the production of gaseous oxygen and nitrogen, and there are devices for the production of liquid oxygen and nitrogen. But as far as the basic process is concerned, there are four main types, namely, high pressure, medium pressure, high and low pressure and full low pressure process. The production scale of China’s air separation equipment has been from the early production of only 20m3/h (oxygen) oxygen generator, and now has the ability to produce 20000m3/h, 30000m3/h and 50000m3/h (oxygen) oversized air separation equipment.
Air separation equipment is a large complex system, mainly composed of the following subsystems: power system, purification system, refrigeration system, heat exchange system, distillation system, product delivery system, liquid storage system and control system.
Power system: mainly refers to the raw material air compressor. The air separation equipment separates the air by low temperature to obtain oxygen, nitrogen and other products, which is essentially completed by energy conversion. The energy of the device is mainly input by the raw air compressor. Accordingly, most of the total energy consumption required for air separation is the energy consumption of raw air compressors.
Purification system: composed of air precooling system (air cooling system) and molecular sieve purification system (purification system). The compressed raw material air temperature is high, and the air precooling system reduces the temperature of the air through contact heat transfer, and can wash the harmful impurities such as acidic substances. The molecular sieve purification system further removes water, carbon dioxide, acetylene, propylene, propane and nitrous oxide from the air, which are harmful to the operation of the air separation equipment.
Refrigeration system: The air separation equipment is cooled by expansion, and the refrigeration of the entire air separation equipment strictly follows the classic refrigeration cycle. However, usually referred to as air separation refrigeration equipment, as long as it refers to: expansion machine.
Heat exchange system: The heat balance of the air separation equipment is accomplished through the refrigeration system and the heat exchange system. With the development of technology, the current heat exchanger mainly uses aluminum plate warped heat exchanger.
Distillation system: the core of air separation equipment, the important equipment to achieve low temperature separation. High and low pressure two-stage distillation is usually adopted. As long as it consists of a low pressure tower, a medium pressure tower and a condensing evaporator.
Product delivery system: Oxygen and nitrogen produced by air separation equipment require a certain pressure to meet the use of subsequent systems. As long as it is composed of a variety of different specifications of oxygen and nitrogen compressors.
Liquid storage system: The air separation equipment can produce a certain amount of liquid oxygen and liquid nitrogen and other products to enter the liquid storage system for use when needed. As long as it is composed of a variety of different specifications of storage tanks, cryogenic liquid pumps and carburetors.
Control system: The large air separation equipment adopts the computer distributed control system, which can realize automatic control.
Air separation equipment from the process can be divided into five basic systems:
Impurity purification system: mainly through air filters and molecular sieve absorbers and other devices, to purify the air mixed with mechanical impurities, water, carbon dioxide, acetylene and so on.
Air cooling and liquefaction system: mainly composed of air compressors, heat exchangers, expanders and air throttling valves, etc., which play the role of deep freezing of air.
Air rectification system: the main components are rectification tower (upper tower, lower tower), condensation evaporator, subcooler, liquid air and liquid nitrogen throttle valve. It plays the role of separating various components in the air.
Heating and blowing system: The purification system is regenerated by heating and blowing.
Instrument control system: Control the entire process through various instruments.