Back Pressure Issues in Pipeline (pulsing/vibrations)
Back Pressure Issues in Pipeline (pulsing/vibrations)
(OP)
Hi guys, this is my first post in this forum.
I am an operator at a Water Treatment plant and have been offered my first project so want to do a good job.
Poly electrolyte is pumped into a centrifuge to thicken the sludge inside and help dewatering. The poly is plumbed into the sludge input pipeline.
Twice a day we need to flush the centrifuge with water which flow flows through the sludge feed line. When this happens the water also flows back through the pipeline where the poly is pumped from.
The flush water makes it all the way back to the discharge of the poly pump and causes a lot of pulsing of the small <1" plastic pipework. This causes leaks around the discharge valve and isn't good for the pipework in general. There is a rubber section installed to help damped the pulses but it is only held on with hose clips so it leaks there too.
I would like to stop this flow of water going back into the poly dose line. A nsimple non-return may work but may just change the area of pressure buildup.
Maybe a flanged rubber section intead of the rubebr hose may be a good idea also. Or some typoe of pressure relief valve. There is a sustaining valve already on the poly discharge side, but it doesn't work.
Please say if you would like me to draw a diagram to make things clearer.
Anyone got any ideas??
Thanks,
Heath
I am an operator at a Water Treatment plant and have been offered my first project so want to do a good job.
Poly electrolyte is pumped into a centrifuge to thicken the sludge inside and help dewatering. The poly is plumbed into the sludge input pipeline.
Twice a day we need to flush the centrifuge with water which flow flows through the sludge feed line. When this happens the water also flows back through the pipeline where the poly is pumped from.
The flush water makes it all the way back to the discharge of the poly pump and causes a lot of pulsing of the small <1" plastic pipework. This causes leaks around the discharge valve and isn't good for the pipework in general. There is a rubber section installed to help damped the pulses but it is only held on with hose clips so it leaks there too.
I would like to stop this flow of water going back into the poly dose line. A nsimple non-return may work but may just change the area of pressure buildup.
Maybe a flanged rubber section intead of the rubebr hose may be a good idea also. Or some typoe of pressure relief valve. There is a sustaining valve already on the poly discharge side, but it doesn't work.
Please say if you would like me to draw a diagram to make things clearer.
Anyone got any ideas??
Thanks,
Heath





RE: Back Pressure Issues in Pipeline (pulsing/vibrations)
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
RE: Back Pressure Issues in Pipeline (pulsing/vibrations)
Do you have a polymer wetting system where you are mixing the liquid polymer and water?
Another option is to install a new water line and inject the water near the centrifuge. In this alternative, you may install a plug valve in the sludge pipe. The valve (when closed) would prevent water from backflowing into the sludge pipe.
A schematic would be helpful.
RE: Back Pressure Issues in Pipeline (pulsing/vibrations)
RE: Back Pressure Issues in Pipeline (pulsing/vibrations)
RE: Back Pressure Issues in Pipeline (pulsing/vibrations)
Polymer is usally mixed with water so that the polymer can be used more economically. The injector/mixing ring is used for the same purpose.
Are you shutting the polymer system pump down when you wash out the sludge pipe? If not, that may be the problem.
You need to add a block valve on the polymer line prior to where the polymer line enters the sludge pipe. Shut the block valve when you want to wash out the sludge pipe.
If you install the block valve, consider adding a relief valve in case someone turns on the polymer pump when the block valve is inadvertently left closed.
RE: Back Pressure Issues in Pipeline (pulsing/vibrations)
Maybe a non-return valve so we don't need to climb up and close it ourselves.
RE: Back Pressure Issues in Pipeline (pulsing/vibrations)
RE: Back Pressure Issues in Pipeline (pulsing/vibrations)