VSD/VFD Pump Controller PLC

[andiparadise]

Dear Expert,

I have a question for certain condition as describe (commissioning step):

- a pump intent to serve multi-product of hydrocarbon. Let says product A and B. When the pump serve the Product A, the demand and certain capacity of the operation is satisfy. The pump using VSD to make power consumption effective and to make the rpm decreasing smoothly until the capacity of product reached.
- When the pump served the Product B ( different SG with product A ) the capacity demand of the operation is not satisfied (larger than demand requirement). We have done any trial and error to solve the problem, and we got one. We stop the pump suddenly by "mother" controller PLC. BUT it is not satisfied enough to do, because we need the smooth decreasing rpm of motor&pump to meet the certain capacity (consider life time of pump and power consumption efficiency).

Is there any suggestion or advice to solve my problem ? Maybe some of you ever met same problem that I am facing right now

 

[LittleInch]

andi - I can sense English is not your first language, but this looks like it has gone through google translate and now doesn't make much sense.

When changing from one product to another, a VSd can maximize your throughput by changing the speed of the pump (up or down) until you reach your required flow or you hit some other limit such as max operating pressure or max pump speed. Normally change of speed can be set in the controller to a certain ramp speed.

I'm confused by your text as to what your problem actually is.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[lilliput1]

Can the speed of the pump be over speed up by the VFD to meet the flow demand without overloading the pump motor? Get a pump curve from the manufacturer corrected for product B SG and at the rpm needed to meet flow requirements. Compare motor bhp requirement vs motor capacity.

 

[micalbrch]

What kind of pump are you using? A centrifugal pump or a positive displacement pump? How is the VFD adjusted, manually or is there any signal which tells the VFD to speed up or slow down?