What volume does “hold-up volume” refer to?
Thread Content
In the case of pumps that provide several functions such as reflux and transferring liquid distillate to storage, the hold-up volume of the corresponding vessel will be equal to the largest volume calculated for each function. What does \"hold-up volume\" refer to in this context? “How should we understand the phrase “in the case of pumps ensuring several services such as reflux and liquid distillate to storage”? Thank you! My translation is: “If the pump ensures certain operating conditions such as backflow and the transfer of liquid distillates to the tank area, then the volume of the relevant containers should be equal to the maximum volume calculated for each such operating condition.”
Personally, I think \"hold up\" refers to the amount (volume) that can be stored. In the case of pumps that are used to ensure the storage of various fluids such as those used for reflux and liquid distillation, my translation is: \"In order to ensure that the pump can meet the storage requirements for various processes (such as reflux fluid and distilled liquid), the amount of liquid that can be stored in the container should be equivalent to the maximum amount calculated in the design.\""
In my opinion, this hold-up volume should be understood as the \"liquid storage volume\"; it is used to calculate the pumping back pressure. Using the maximum volume as the liquid storage volume for calculating the outlet back pressure ensures that the pump can continue to function properly when the storage tank is nearly full.
It might be for calculating the volume of the reflux tank at the top of the tower.