molecular sieve purification system?
The elevated steam is partially condensed for many times, and nitrogen and a small amount of excessive hydrogen are on the top of the tower (the liquefaction temperature of hydrogen is lower than that of nitrogen, so it is impossible to condense), which contains about 40% of argon. The argon produced by evaporation at the bottom of the tower is the rising gas required for distillation. The gas nitrogen is used as the heat source from the evaporation of the liquid argon in the lower tower. This cycle operation, to achieve continuous refrigeration. For oxygen machines, it is also a refrigeration process to reduce the air temperature to the liquefaction temperature. Therefore, there must be a compressor and at the cost of power consumption. Only the air in the oxygen bottle is air as the working medium, and the cooling is achieved by compressing and expanding first. Then it cools the air itself to liquefy until the liquefaction temperature is reached.
There is a certain distance between the fins of the tooth fins, there are cuts and protrude towards the direction of the fluid. For the disturbance and failure of laminar boundary layer, it has good heat transfer performance, and is often used in heat exchanger with low temperature difference between high and low temperature fluid. One is to strengthen the heat transfer between gases, and the other is to facilitate the precipitation and removal of water and carbon dioxide. Ideally, some processes may be reversible, for example, when the gas in the cylinder expands, the weight lifting object does its work, and when it falls, it may compress the gas back into its original state. According to the definition of entropy, entropy is invariable before and after reversible adiabatic process. In this regard, the operation of the crude argon tower should be stopped first to improve the temperature of the crude argon condenser. After thawing, the crude argon tower is injected gradually, and the nitrogen content in the tower should be noted. The nitrogen content of more than 0.1% will not only make the distillation difficult to condense, but also increase the content of crude argon, which will affect the work of the fine argon tower.
Under the normal operation condition of large air separation equipment, the temperature of pumping in air separation equipment is -110~-120 ℃. At this time, the water vapor is basically removed, carbon dioxide is absorbed, and the air entering the expander will be a clean gas without water and carbon dioxide. However, the accumulator is still in the cooling phase at the beginning of the start-up. Special attention should be paid to prevent the cold damage caused by the continuous gasification of the fluid. The water diversion pipe should be inclined upward and made into upward bend within the range of 800 mm near the cold box, with a height of about 6-10 times the diameter, but not less than 200 mm. When the valve is closed, a liquid seal is formed, and there will be no liquid gasification of the valve flowing continuously on the valve side. Some drain pipes are equipped with heating sleeve to prevent ice;
It is actually difficult for large air separation equipment manufacturers to directly determine the moisture content in the air. It is well known that the partial pressure produced by water vapor is related to its content and is proportional. Therefore, the partial pressure PW (PA) produced by the moisture vapor in the air can also be used to represent the absolute humidity of the air (kg/m3). In order to avoid bias current, the resistance difference of plate elements should be strictly required in design and manufacture. If Japan stipulates that the resistance difference of unit group should be controlled in ± The resistance difference of the two switch channels should be controlled within 1.5% of the soil. Each unit group of heat exchanger is generally equipped with product regulating valve (without accumulator). For example, 10 single unit units of domestic 6000m3/h air separation equipment are equipped with oxygen outlet butterfly valve, and each group is equipped with pure nitrogen outlet butterfly valve. For the unit group with high intermediate temperature, open the product regulating valve to increase the product flux, that is, increase the cooling capacity, which can reduce the intermediate temperature;