Selection of vacuum pump for the stripping tower
Thread Content
We have 2 towers that use negative pressure stripping to remove fatty acids. The operating conditions are as follows: Vacuum: 5 mbar; Temperature: 255–270°C. The vacuum pump used is a steam jet vacuum pump. Then two problems arise: 1. The use of steam jet pumps results in an excessive amount of wastewater ； 2. The temperature of the water coming out of the steam jet pump does not drop; although a condenser is used, it is not sufficient, and cold water has to be added, which further increases the amount of wastewater generated. To this end, we are planning to find a way to replace the vacuum pump. But then new problems arose. Which vacuum pump should be chosen to meet our requirements? An experienced colleague at the company told me that steam ejector pumps are generally used in distillation towers; otherwise, if ordinary mechanical pumps are used, the steam will freeze. If it is to be converted into a mechanical vacuum pump, the cost will be extremely high, amounting to 2 million.
What is used to cool steam jet pumps?
How large is the exhaust volume? It only shows that the condenser behind you is poorly designed! What is the temperature of the cooling water? Is a ejector or a liquid ring pump used for the final stage?
The original poster didn’t mention how large the air extraction capacity is. It should be indicated on the nameplate. Additionally, the diameter and height of the tower are not specified either; there are requirements regarding the feed rate and output rate as well. Finally, regarding the condenser mentioned by the original poster, the problem isn’t that condensation doesn’t occur – I think the issue lies in the selection of the equipment. Ask the personnel in charge of the process there to see if there are problems with the process parameters. If that doesn’t work, then either the refrigerant medium needs to be changed or the heat exchange area increased.
It’s difficult to give an answer without knowing parameters such as the pumping volume and the medium being pumped; for mechanical pumps, a Roots pump combined with a liquid ring pump, or a liquid ring pump combined with a jet pump, can be used
Is it used in oil refining? Steam ejectors can be used for the first 2 stages, while water ring pumps can replace those 2 stages. The overall steam and water consumption is reduced.