Hi, I was recently hired for something I'm not even remotely qualified for. I have to help figure out a solution to a pumping issue.
What we want to do is see if we can use one pump as a booster to a slow high pressure pump feeding a high pressure system. Then we want to use the same pump to flush the system with hi flow. But I'm quickly realizing this is hard to do.
The flow will be severely restricted when it is in booster mode. Pretty much every pump I've looked at that can deliver 30gpm doesn't seem to be able to do 1gpm. I get the impression that you can operate it at that rate but it will hurt the pump.
Can anyone give me some guidance on how to think about this problem? We can get a centrifugal pump with a vfd. The vfd can lower the H/Q curve when running as a booster, but even then it looks like it's physics problem and you just can't get 2 or 3 bars of pressure with a pump designed to deliver 30gpm when it's being restricted to 1gpm. So I was thinking we can install a control valve that will just recirculate the excess flow so we can operate it in the safe range? But even then most of the pumps I'm looking at we will be wasting like 90% of the water we are pumping during boosting. But if we go this route how do we appropriately size it such that we waste as little energy as possible? How do I think about things like impeller size and rated rpm? Or what are the things to look for that actually make a difference? Sorry, did I already say I'm in way over my head here?
I've been looking at curves of many pumps and they are often so different in shape, with some basically flat for most of the low end range and some look like they are more continuously sloped (lower head for higher flow). I don't understand pumps well enough to have any idea why this happens or which shape curve will work best.
I know there are multistage pumps. will that solve our problem? Should I just tell my boss we need two pumps? One won't work?
What we want to do is see if we can use one pump as a booster to a slow high pressure pump feeding a high pressure system. Then we want to use the same pump to flush the system with hi flow. But I'm quickly realizing this is hard to do.
The flow will be severely restricted when it is in booster mode. Pretty much every pump I've looked at that can deliver 30gpm doesn't seem to be able to do 1gpm. I get the impression that you can operate it at that rate but it will hurt the pump.
Can anyone give me some guidance on how to think about this problem? We can get a centrifugal pump with a vfd. The vfd can lower the H/Q curve when running as a booster, but even then it looks like it's physics problem and you just can't get 2 or 3 bars of pressure with a pump designed to deliver 30gpm when it's being restricted to 1gpm. So I was thinking we can install a control valve that will just recirculate the excess flow so we can operate it in the safe range? But even then most of the pumps I'm looking at we will be wasting like 90% of the water we are pumping during boosting. But if we go this route how do we appropriately size it such that we waste as little energy as possible? How do I think about things like impeller size and rated rpm? Or what are the things to look for that actually make a difference? Sorry, did I already say I'm in way over my head here?
I've been looking at curves of many pumps and they are often so different in shape, with some basically flat for most of the low end range and some look like they are more continuously sloped (lower head for higher flow). I don't understand pumps well enough to have any idea why this happens or which shape curve will work best.
I know there are multistage pumps. will that solve our problem? Should I just tell my boss we need two pumps? One won't work?
