Gravity Flow Pipe Surge
Gravity Flow Pipe Surge
(OP)
I am pumping a slurry (10% solids) through an 8" steel pipe 19,000' long and on a downgrade of 1%. At the end of the line, we are seeing large surges of fluid followed by lulls. I am guessing that this is being caused by the pipeline being able to carry more via gravity than the pump is producing. According to my calculations, the pipe can handle around 380 GPM at full flow, but the pump is only putting in around 160 GPM.
Question 1: Would this situation alone be causing the surges?
Question 2: Could the solution be as simple as partially closing a valve about 1000' from the outlet? Or is a surge tank a better idea?
Thanks to anyone that may have some experience in this area.
Question 1: Would this situation alone be causing the surges?
Question 2: Could the solution be as simple as partially closing a valve about 1000' from the outlet? Or is a surge tank a better idea?
Thanks to anyone that may have some experience in this area.





RE: Gravity Flow Pipe Surge
RE: Gravity Flow Pipe Surge
Thanks again.
RE: Gravity Flow Pipe Surge
If the pump can handle the correct flow, then there needs to be a device at the outlet to provide a head loss. This would keep the line under pressure and ensure full flow.
In other slurry lines I have seen ceramic chokes used to reduce the velocity, disspate the energy and keep the line full. What you are observing may well be vapour pockets arising from negative transients in the pipeline. It could be air coming out of solution due to low pressure areas in the line.
Other systems I have been involved with dropped 1000m in 8000m through some 200+ vented drop boxes. These were used to dissipate the energy. At Bougainville Copper, before the troubles, they installed Warman slurry pumps to act as turbines to recover energy whilst dissipating energy.
AFT's Impulse will model slurries and downhill pumped pipelines for transient events.Look at www.aft.com. They also offer consulting services.
RE: Gravity Flow Pipe Surge
Stuart