There is a certain amount of argon in the rising steam of stripping section and the steam after liquid air throttling. In the process of rising, some steam will condense into liquid after encountering downflow cold liquid. Oxygen and argon, which are difficult to volatilize, condense more into the liquid phase than nitrogen.Some air separation processes are different. There is no butterfly valve at the nitrogen outlet of the upper tower. At the same time, the expanded air is only sent to the liquefier without going through the cooler. For such a process, gas can be sent to the upper tower at the beginning of liquid accumulation. Because it can make full use of low temperature gas to cool the upper tower, and the cooling capacity of the gas discharged from the upper tower can be fully recovered in the subcooler and liquefier.The gas and liquid in the air separation unit are at very low temperature. Low temperature gas is below the ambient temperature until - 193 ℃; liquid air is - 173 ℃, liquid oxygen is - 180 ℃, liquid nitrogen is - 177 ～ - 193 ℃. These low-temperature gases and liquids are obtained at a cost (the electric energy consumed by the compressor), and their cooling capacity should be recycled in the heat exchanger as far as possible.
DEAR Biogas purification unit.If the molecular sieve bed is uneven and the thickness of the bed through which the airflow passes is different, the maximum temperature will not be reached at the same time at the outlet. Several peaks may appear after mixing, or the whole peak may be relatively flat, the peak temperature will decrease, and the shape of the cold blowing curve will also become "short and fat". In this case, heating and cold blowing to the specified temperature often takes longer.Saturation temperature and pressure are terms in gas-liquid equilibrium. If a closed container is not filled with liquid, some liquid molecules will enter the upper space, which is called "evaporation". With the increase of the number of vapor molecules in space, the vapor pressure produced by it also increases. At a certain time, the number of vapor molecules in space does not increase.When the air separation unit of molecular sieve adsorption purification process is restarted after a short-term shutdown, attention should be paid to: the air compressor should be boosted slowly to prevent the impact on the air cooling tower due to the sudden rise of pressure. The water level of the air cooling tower should be paid attention to to prevent the molecular sieve adsorber from entering water due to the high water level;
DEAR Biogas purification unit.Heat exchange equipment is an essential equipment to achieve air liquefaction, separation and maintain the normal operation of the device. Moreover, whether the heat exchanger works normally or not directly affects the economy of the air separation unit. Although there are many types of heat exchangers in air separation plant, they can be divided into three types according to their heat transfer principles: 1) inter wall type. 2) Regenerative. 3) Hybrid.DEAR Biogas purification unit.At present, most of the cold insulation materials in the cold insulation box of air separation plant are pearlite. Pearlite is a particle with small apparent density, which is easy to fly. It can invade the five senses, irritate the throat and eyes, and even inhale into the lungs through the respiratory tract. Therefore, wear protective masks during operation.The design parameters of general purifier are: working pressure is 2MPa (gauge pressure), working temperature is 30 ℃, switching time is 8h. If the pressure of high-pressure air is not controlled during the heating of fractionator, the working pressure is likely to be lower than 1MPa (gauge pressure). Although the working temperature of purifier is still 30 ℃, the water brought into purifier per hour will double the design value.
