Installing a Spill Back Flow

[cilacap]

Installing a Spill Back Flow

I will install several new pumps as crude transfer pumps from storage tank to mixing tank. The pump will be operated in large various of capacity. The plant operating mode and availability of specified crude are reasons. Choosing pump specification to be difficult due to much different of capacity between maximum and minimum flow required. In planning I put maximum operating flow as pump rated capacity, but I am not sure that minimum operating flow able be fulfilled by pump as minimum continuous flow.

I make a plan to install spill back flow from discharge line back to storage tank or suction line in purpose to keep in order to pump work at least at minimum continuous flow when capacity required is lower and remain flow send back to storage tank or suction line.

Look at mention my planning; I need advices for some questions below;

1.Whatever does matter I have to consider for installing a spill back flow?
2.To install pipe line from discharge line to storage pump will spend many material, what effect to pump and fluid flow when back flow from spill back line entrance to suction line?

Thank you for your attention.

Ari Dwikoranto- Mechanical Engineering

 

[ccfowler]

It is important to pay attention to the energy dissipated in the recirculating flows from two perspectives. First, the additional energy required for pumping the recirculating flows can represent a very substantial burden in energy usage that may not be justified by maintenance and repair savings. Second, returning the recirculating flow to the suction line can result in a substantial increase in the temperature of the flow thereby changing the density and viscosity of the fluid and altering the system's performance characteristics. Returning the flow to the source tank is usually the best choice, but using a heat exchanger to cool the recirculating flow and return it to the suction line may make more sense if the return line to the tank would be very long.

This may be an application where the use of adjustable speed drives may make sense, but only a very thorough analysis of the application can clarify the choices. It is important to recognize that simply installing an adjustable speed drive does not assure energy savings. Indeed, the losses inherent in an adjustable speed drive can be sufficiently significant to preclude its suitability for a particular application.