At the beginning of pumping, the main thing is to master the speed of pumping. If the air extraction speed is too slow and the air extraction volume is too small, the temperature in the middle of the accumulator will not drop for a long time, and the temperature difference at the cold end is large, which is not conducive to the establishment of the self cleaning condition of the accumulator; if the air extraction speed is too fast, the temperature of the CO2 adsorber will rise, and the temperature in front of the unit will rise, resulting in the temperature rise at the cold end.When the valve is closed to a certain extent, the automatic valve of the central suction pump is suddenly opened, the central suction volume increases sharply, and the temperature of the CO2 adsorber rises quickly. In order to avoid this phenomenon, we should first open the large-7 valve and gradually close the small-4 valve. If you still can't pump out air, you can turn down the valve properly.Air is a mixed gas, and the gas separation process cannot be spontaneous. In order to achieve the separation of oxygen and nitrogen, work must be consumed. If the separation process is reversible, that is, without any energy loss, the work consumed is the minimum, which is called the separation minimum work.
DEAR Air separation equipment.The purpose of throttling is to obtain low temperature, so the greater the effect of throttling temperature drop, the better. Pressure difference before and after throttling. The greater the pressure difference before and after throttling, the greater the temperature drop. To increase the pressure before throttling, we must increase the discharge pressure of the compressor, and correspondingly increase the energy consumption of the compressor, which is not what we want.Welding quality shall be strictly guaranteed during manufacturing and installation. After installation and before start-up, strict leak detection and pressure test must be carried out, and problems found shall be handled in time to avoid passivity after start-up. In operation, the method to check the leakage of the switching heat exchanger can be summarized as: flow method. When a large amount of leakage occurs between the product oxygen or product nitrogen channel and the air channel, the production of oxygen or nitrogen increases significantly.
DEAR Air separation equipment.For pure matter, there is no essential difference between evaporation and boiling. Boiling point is also called "evaporation temperature". When the liquid sealed in the constant pressure container is heated, the temperature T of the liquid is lower than the boiling point ts, and it is all in the liquid state, which is called supercooled liquid;In this case, the operation of the crude argon column should be stopped first, and the temperature of the crude argon condenser should be increased. After thawing, gradually put the crude argon column into operation again; pay attention to the nitrogen content in the fraction. When the nitrogen content exceeds 0.1%, it will not only make it difficult to condense the fraction, but also increase the nitrogen content of the crude argon, which will affect the operation of the refined argon tower.The pipe is filled with both air and backflow gas, so the temperature of hot blowing period (filled with air) and cold blowing period (filled with backflow gas) can be measured. The cold end temperature is measured at the bottom of the accumulator with a resistance thermometer. The following describes how to measure the temperature condition of the accumulator and calculate the temperature difference between the hot end and the cold end with some measured data.
Low temperature valve is often flexible in normal temperature, low temperature is very tight, or even open. The main reasons for the valve stuck at low temperature are as follows: during installation, the pre stress is produced due to the unreasonable configuration of the valve and pipeline; or the valve position is changed due to the poor cold compensation capacity of the pipeline at low temperature; or the valve is deformed due to the lack of support at low temperature; or the valve is improperly fixed and the cold box is deformed at low temperature, which affects the concentricity of the valve stem and valve body.When the heat transfer surface of the condensing evaporator is insufficient, to ensure a certain heat load, it is necessary to increase the pressure of the lower tower to increase the heat transfer temperature difference. According to the characteristic curve of the air compressor, with the increase of the exhaust pressure, the air volume will also decrease, which will also reduce the oxygen production.
