Selection of sub-tank pumps
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Explanation: The vacuum level in the vacuum tower is 90 kPa, and it is necessary to discharge material from the bottom of the tower. What type of pump should be used for this purpose – a centrifugal pump or a gear pump? The liquid level is about 3 meters above the pump. I’m worried now that the tower is in a vacuum environment – will the pump be able to draw out the material? At the same time, the temperature is too high and close to the boiling point, raising concerns about cavitation in the pump! How should the pump be selected in this case? What issues should be noted? I hope all of you experts can give me some guidance! Thank you!
Could considering using the gravity of the medium to discharge it into a vacuum tank be an option, thereby switching between the two tanks that are available? Apply positive pressure to one of them to discharge the material and switch for use. For reference.
Only a submersible design can be used; otherwise, the pump cannot function
I’ve considered it; in that case, the stability of tower operation is poor.
Is the pump located below the liquid level? Could it be something like a submersible pump?
You don’t seem to understand what I mean; the pump needs to be submerged in a liquid, for example, a vertical cartridge pump using VS6
I’ve never worked with this type of pump; I just looked it up online. The motor is located outside the container, while the pump is submerged in the liquid. After comparing the parameters, we found that the pumps produced by several domestic manufacturers have too high a flow rate; we need ones with a lower flow rate.
The motor is not in the liquid; the pump is in the liquid
A pneumatic self-regulating valve can be installed for this, and it is possible to connect it to a level gauge. In fact, no matter what is used, it’s all just based on the use of pressure difference for removal. If a pump is used, there will be many inconveniences, such as sealing issues between the pump shaft and the tank ； Issues related to the inspection and maintenance of pumps within containers, including whether the materials in use will cause chemical reactions with the lubricants, packing, and other materials constituting the pump body; as well as whether frictional static electricity generated when the pump fails could pose safety risks. . . . Setting up negative pressure outside the container for suction is the best option; let’s wait and see: lol
What kind of material is it? Is its viscosity high? What is the vapor pressure at this temperature? No conclusion can be drawn without specific parameters
In a vacuum with a temperature close to the boiling point, careful selection is required when choosing a centrifugal pump. Although a check valve can be installed to improve safety, cavitation of the equipment also needs to be taken into account for maintenance and replacement. Because as you said, your traffic demand is low, and in that case a gear pump is indeed a good choice :)