Vibration in Cane Juice Pump Line

So what exactly is vibrating, and have you measured the vibration in order to know what the frequency and amplitude of the vibration is?

This could be caused by many different things and the frequecy of the vibration will help to determine what... Is this a new problem, or is this a problem that has recently developed?

If the vibration is related to vane pass frequency (number of vanes times rpm) then it may well be a hydraulic problem. Have you tried varying the flow to see if the problem goes away? Can you shutdown and block in one pump and make the vibration go away?

If the vibration is related to running speed, it may be a pipe support or pipe stress problem. Are all the spring hangers, pipe supports, pipe slides and guides present and working properly?

Bottom line is we need much more information to help...

Few Inputs...amazing how basic inputs are the most important..

a)What type of pump? Centrifugal or PD pump?

b) Is the vibration reduced if you use one pump?

c) Do you have non return valves at the discharge line ? Each pump should have a non-return valve at the discharge line.

d) Did you try throttling the discharge line to see whether the vibration reduces?

( Here i am assuming you are using a centifugal pump)..if you are using positive displacement pump then ignore the suggestion.

Also check the impeller for clogging..

Cheers

the first thing to do : check the current during regular duty.

if it is high - seprate the engine from the motor & check the current of the engine without avy load.

if the current is high U should repair your engine, else U should check the pump & the pipe line valves.

Good suggestions above, also if its a Centrifugal pump, check to make sure there is no air getting in the inlet that would cause cavitation in the pump.

phoenix911

Jawed,

In order to analyse the problem some additional info is required :

1. Do uo have vibration problem with one pump in operation or when two pumps are run at the same time?

2.What is the pressure gauge reading when one pump is in opeartion?

3. What is the gauge reading when two pumps are in use simultaneously?

4. What is the length of disharge line and what is the height to which the liquid is lifted to ( vertcal lift)?

With 400 mm dia impeller you are almost working to full capacity if the pump delivers 200 m^3/hr.

We should check the mechanical aspects as suggested by others befoe checking the hydraulic aspect.Usually a plant designer won't make mistakes in the Pump selection or the layout (unless it is his first plant).If the problem is from day one,you have a reason to check the hydraulics for which the data requested will be needed.

Centrifugal pump capacity will add only when the shut off head is higher than the system head.In any case,it will not be a straight addition of individual capacities.This is where the data of pressure gauge readings will help.Alternatively,we can calculate the friction loss once the lenght with number of bends,valves and vertical lift are known.

See if you can help with this data.

Regards

Chuck

Is there a chance that both pumps are timed to discharge at the same time and then intake at the same time. This would cause some vibration.

Are both pumps operating or is one a backup for the other?