When the air temperature into the air separation unit rises abnormally, more heat needs to be released in the heat exchanger to cool the gas to a certain temperature. The heat transfer area of the heat exchanger is fixed, which can only be achieved by expanding the heat transfer temperature difference.DEAR Air separation equipment.The length of plate unit is about 5.4m, while the length of switching heat exchanger is 6m. Due to the simple equipment and low cooling loss in the device, the intermediate temperature of the heat exchanger can be generally higher or similar to the circulating temperature of the long plate heat exchanger.In order to avoid the increase of hydrocarbon concentration in liquid oxygen, according to the material balance, it is necessary to extract part of liquid oxygen from the main cooler and extract part of hydrocarbon from the main cooler. The minimum amount of liquid oxygen extracted is equal to 1% of the gas oxygen output, and then gasified separately.DEAR Air separation equipment.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.
When blowing out the oil and water at all levels of the air compressor, we can see that there is always a large amount of water blowing out from the separator. Where does the water come from? This is because the amount of water that can be contained in every cubic meter of air mainly depends on the temperature, but has little to do with the total air pressure. For example, at 30 ℃ and 0.1MPa pressure, the saturated moisture content in the air is 30.3g/m3.DEAR Air separation equipment.In addition to reducing air loss and equipment resistance as much as possible to increase air volume, and reducing cooling loss, incomplete heat exchange loss and leakage as much as possible to reduce expansion air volume, this paper mainly analyzes the method of adjusting the output from the perspective of adjusting distillation conditions.First, increase the circulating current to keep the front of the machine at a higher temperature (e.g. - 120 ℃), so that the carbon dioxide content in front of the machine is in an unsaturated state. After expansion, carbon dioxide is not easy to precipitate in the machine. When the temperature of the cold end reaches - 150 ℃, the amount of carbon dioxide brought into the expander is very small, so the bypass and circulation can be cut off temporarily, so that the temperature in front of the expander can be reduced rapidly, and the expander will not be blocked if it is forced to cross the carbon dioxide freezing zone in about 10 minutes.
Non switching plate fin heat exchanger is a kind of heat exchange equipment that all the channels of the heat exchanger, including the channels of air, oxygen, nitrogen and sewage nitrogen, do not change with time and flow stably. It is generally used in the low pressure process of molecular sieve, but also useful in the medium pressure process. It is the most important heat exchanger in the air separation plant, also known as the main heat exchanger.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.When the liquid is discharged, freezing occurs when the temperature drops. In order to prevent this situation, the valve should be continuously turned at the initial stage of discharging liquid, so as not to freeze the valve stem. If freezing has occurred, steam can be used to heat the stuffing box before closing it.
