DEAR Air separation equipment.When the gas is expanded by external power through the expander, the internal energy will be consumed, and the effect of temperature drop is much greater than when the throttle is not expanded by external power. Especially for the low pressure air separation plant, the refrigeration capacity mainly depends on the expander. However, the higher the inlet temperature is, the greater the effect is. In addition, no liquid is allowed in the expander to avoid damaging the blades.If the temperature is increased by 1 ℃, the energy consumption of the air separation unit will increase by about 2%. Lowering the inlet air temperature can not only improve the economy of the air separation plant, but also reduce the saturated moisture content in the air. For example, when the absolute pressure of air is 0.6MPa and the air temperature drops from 40 ℃ to 30 ℃, the saturated moisture content in every 1kg of air will be reduced by about 40%.DEAR Air separation equipment.The argon fraction is separated from oxygen and argon in a crude argon column. The argon fraction enters from the bottom and crude argon containing about 95% argon is obtained from the top. Because the boiling points of oxygen and argon are close to each other, it is difficult to separate them. About two thirds of argon is washed down.
The oxygen storage spherical tank should be inspected at least once every two years, and the wall thickness should be measured every five years. For those with serious corrosion, the above inspection period should be shortened and anti-corrosion measures should be taken. The inner wall of the tank can be coated with long-term corrosion-resistant inorganic zinc rich coating (mainly composed of zinc powder and water glass). In order to reduce the working stress of the tank wall, the pressure of the spherical tank installed in the North should be reduced or relieved when it is shut down in winter.The long tube condensing evaporator is evaporation inside the tube and condensation outside the tube. Its boiling intensity and condensation intensity are related to the geometric size of the tube. The experimental results show that when the unit heat load Q (heat transfer per unit area and time) is constant, the larger the ratio L / Di of tube length L to tube inner diameter Di, the stronger the boiling heat release.
DEAR Air separation equipment.For the main heat exchanger of molecular sieve adsorption process, the main reason for the decline of heat transfer performance is the improper operation of the adsorber. Due to the inflow of water into the molecular sieve adsorber, or due to the impact of air flow, the molecular sieve is powdered, which brings the powder into the heat exchanger and adheres to the surface of the heat exchanger channel, affecting the heat transfer performance, resulting in the expansion of the temperature difference at the hot end.DEAR Air separation equipment.Part of the liquid air is sent to the condensing evaporator of the crude argon tower and evaporated completely, then the steam is sent to the upper tower. Its characteristics are opposite to the first one. Generally, the third way between the two ways is adopted, that is, part of the liquid air passes through the crude argon tower, but not all of it evaporates. This can not only ensure the normal operation of the crude argon column, but also reduce the impact on the main column.
DEAR Air separation equipment.In recent years, there are more and more air separation units using molecular sieve purification process, and the main heat exchanger is non switching plate fin heat exchanger. No matter what process the heat exchanger is used for, the arrangement of cold section and hot section is different from that of switching heat exchanger.Failure on the stem. The common fault is that the screw thread on the valve stem and screw sleeve is worn, which makes the valve unable to close. Generally, the screw thread of the valve stem is not easy to be worn, while the female thread on the screw sleeve (brass) is easy to be damaged. Most of the reasons are too much force when the valve is opened, or hard screw after the valve is opened or closed, so that the screw thread is damaged.Shorten the switching time and reduce the cold end temperature as soon as possible; when the cold end temperature meets the process requirements and the air separation unit enters the fourth stage, the expansion heat exchanger will not be started to prevent carbon dioxide from blocking the expansion heat exchanger.
