The method of changing the air or product gas distribution to adjust the temperature condition is essentially the balance adjustment of cooling capacity between groups, which only transfers the excess cooling capacity from one group to the one with insufficient cooling capacity. If the middle temperature of each group tends to increase (or decrease), it should be adjusted by increasing (or decreasing) the refrigerating capacity of the expander.DEAR Biogas purification unit.This kind of regulation method is only effective when the on-6 valve is closed very small (within one revolution) and the high pressure air pressure is not equal to the pressure in front of the expander. And each adjustment can only rotate 3-5 degrees, not too large.DEAR Biogas purification unit.At the top of the upper tower, gas nitrogen and liquid nitrogen coexist in a saturated state, and they have the same saturation temperature. The absolute pressure of nitrogen out of the upper tower is about 0.13mpa, and the corresponding saturation temperature is - 193 ℃. The temperature of nitrogen saturated steam out of the tower is also at this temperature. The absolute pressure at the top of the lower tower is about 0.55mpa, and the corresponding nitrogen saturation temperature is about - 177 ℃.
For users with external activation conditions, follow the following steps: 1) thoroughly activate the molecular sieve to be filled; 2) remove the air inlet pipe and filter pipe at the top of the purifier to be filled; 3) load the activated molecular sieve into the purifier until it is full, and note the number of molecular sieves to be filled. In order to fill compactly, wooden hammer can be used to knock on the head of the cylinder; 4) after the molecular sieve is installed, the pipeline, filter pipe and valve can be installed again. And attention should be paid to: the screws of connecting flange should be tightened evenly and symmetrically; the valve should be degreased before packing; the packing of nitrogen heating valve should also use high temperature resistant expanded graphite or asbestos wire.DEAR Biogas purification unit.The heat transfer is directly proportional to the heat transfer area, while the surface area of the cold box is not directly proportional to the capacity of the device. Therefore, with the increase of the capacity of the device, the cooling loss per cubic meter of processing air (unit cooling loss) decreases. For some old air separation units with tubular accumulators, the oxygen generator with the same capacity has more equipment in the cold box, relatively speaking, the surface area is larger, and the cold loss will be larger.
In the switching heat exchanger, water and carbon dioxide can not be completely removed. Although the residual amount is very small, it will gradually block the switching heat exchanger over time. In the production, the resistance of the switching heat exchanger is increasing, the free cross section of the gas flow is decreasing, and the amount of air can not enter.The packed tower is a round steel vessel filled with packing (porcelain ring, or plastic ring, etc.). The cooling water is sprayed from the top of the tower and mixed with the air flowing from bottom to top for heat and mass exchange. The air transfers the heat to the cooling water, so that the temperature of the air decreases and the water temperature increases.The better the ability of liquid oxygen to scour the wall of the channel, the more acetylene and other hydrocarbons are not easy to precipitate on the wall, and the carbon dioxide particles are not easy to block the channel section; from the perspective of heat transfer, because the boiling heat transfer coefficient of the liquid oxygen side of the plate fin condensing evaporator is related to the fluid flow, the better the flow is, the greater the heat transfer coefficient is.
