Aromatic extraction unit, vacuum pump at the top of the solvent recovery tower and bottom pump
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May I ask everyone, in the solvent recovery tower of the aromatic extraction unit, the tower operates under negative pressure. So how is the vacuum pump at the top of the tower started? Is the pump at the bottom of the tower started after negative pressure is established, or before it is established? Are the startup procedures for the pump at the bottom of the tower the same as those for a regular centrifugal pump? Thank you all. I’m new to the aromatic compounds industry and there’s still a lot I don’t understand.
First, you need to specify the type of vacuum pump you have, such as a water ring vacuum pump, a steam ejector, or a water jet ejector, and then carry out the operations accordingly based on that specific type.
At the start of operation, a solvent circulation system is first established; the extraction tower and recovery tower are filled with solvent. Once the towers are filled with solvent, the solvent pump is started to create a cold solvent circulation； In the second step, the apparatus is heated to establish a solvothermal cycle. Before heating begins, a vacuum pumping system (steam pump) must be used to create a negative pressure in the system, and only then can the heating process start. In other words, the pump at the bottom of the tower starts operating under positive pressure, which is no different from ordinary centrifugal pumps.
You mention this issue; during normal production, it arises when the pump at the bottom of the recovery tower is switched off
The recovery tower operates under negative pressure during normal production. Is there any difference between a cut-off pump and a regular pump? Thank you
Mm-hmm, thank you, I get it~
When filling the pump, be careful: first open the outlet valve to equalize the pressure in the tower through the return flow, and then slowly open the pump’s inlet valve to start filling it (this is my personal understanding)
The bottom pump starts under positive pressure, with no difference from ordinary centrifugal pumps.