Factors affecting the vacuum pumping system
Thread Content
The vacuum system uses 1.1 MPa steam for vacuuming, with a two-stage ejector, but the pressure drop does not reach the desired level. Apart from system leaks and the flow rate and temperature of the circulating water, what other factors could be influencing this?
1. Efficiency of vacuum pumping equipment； 2 Changes in vapor pressure ； 3 Changes in feed temperature ； 4 Water supply volume and water temperature ； 5 Changes in the liquid level at the bottom of the tower ； 6 Temperature changes at the top of the tower ； 7 Variation in distillation steam volume ； 8 Changes in pull-out rate at atmospheric pressure ； 9 Vapor phase temperature variation.
It might also be affected by a large amount of condensable gases in the system, but this should be taken into account when selecting the equipment
Reply to 3# Ai Erway: It should be an inert gas, right? Additionally, the piping for your circulating water also has an impact; the pipes there need to be curved, and press-fit elbows cannot be used, which results in high resistance in the circulating water flow.
In a steam jet pump, the nozzle is blocked by slag and other substances. Incomplete condensation.
The capacity of a two-stage steam ejector should be to remove non-condensable gases during normal operation; I’m not sure if what the original poster is referring to is the inability to remove such gases when the device is in use. . In the situation I described, the best approach is to use a larger vacuum pump as a starting pump before commencing operation; once the vacuum level is normal, then proceed with the switch-over. . . . Note: The pipeline for evacuating air using the extractor should be kept free of air. . . Also, I’m not sure whether your vacuum pump recycles the non-condensable gases or discharges them outside. . . If it is for venting, then check the steam flow rate; if it is for steam recovery. . . It’s better to try to lower the temperature of the cooling water entering the system. . . . . Or the recycling pipeline is blocked. . Park and do a quick purge. . .
Check the pump; if there is even a tiny amount of debris attached to its internal walls, it will affect its pumping capacity. It’s recommended to clean it out
Steam jet pumps are used for vacuum creation and have a high pumping capacity; they are generally arranged in multiple stages in series. If the vacuum level cannot be increased, it may be due to the presence of large amounts of low-boiling-point substances such as water in the material. The tower system, such as pipelines, valves, or the tower itself, has significant leakage points. Leak in the reboiler or top condenser. The nozzle is worn or clogged. Fouling on the condenser. When the material has a high freezing point, material deposits form inside the condenser. The temperature of the condenser cooling water is high or the flow rate is low. There are leaks or blockages in the atmospheric leg.
Just use a third-stage injector, right? Additionally, considering adding a capture device to perform cryogenic cooling of the exhaust pipeline is also necessary.
Reply to 1# A Shan: Is there a problem with the nozzle’s design?