Impellers For Submersible Pumps

http://www.flygt.com/en-us/Pages/Flygt.aspx

You're a spam.

why you ?? lien

Never mind.

I don't know the answer to your questions but, we use Flyght pumps for pumping extremely silty water at high volumes with no problems. Flyght pumps are commonly used in mining applications up here in Alaska. They are "bullet proof". I have had excellent luck getting information from Flyght. The only common term I've heard for a classification is a "trash" pump.

Thank you for your time and useful comments.

We have proposed a lowering and raising mechanism for the pump installation height to enable us to keep the pump about 0.5 m below the top water level. In this way we will abstract water from the upper layers which should be relatively silt-free.

The construction of a sump at the lowest level is a good idea.

Kind regards

MAK

Thank you, Brich for very useful information.

It will be quite awhile before we will test the pumps as we have to go through a formal procurement procedure. Once, we do that I will definitely keep our learned friends informed. Kind regards

The reply to your three questions are merged in single reply.

You already have specified capacity and head. This capacity is not suitable for turbine type pump. These submersible cntrifugal pumps and are designed for maximum size of solid which can be handled by the pump normally varies upto 12 or 15mm some times bigger than that. Depending on this size impellers are designed accordingly.

Flygt is one of the manufacturer of such pumps. KSB also makes these type of pumps.

Rubbish!!

Of course you noted Q and TDH, I shouldn't read or reply by blackberry! A few additional comments for your consideration:

a. It is possible to 'lift' with centrifugal pumps; i.e. you don't necessarily have to use a submersible pump. Theoretically this is limited to 1 atmosphere / ~30 feet (@sea level), practically I doubt a pump rep would go much beyond 20 feet. I havn't gone through the application engineering for such a case, in general I suspect this pump would be larger, higher initial cost (pump only) and less efficient. And you might scratch your head the first few times you start it, wondering if & when water will move. But it would be more accessible. And you could put a single or dual basket strainer right where you could get at it if suspended solids are projected to be a problem.

b. Previous comments regarding TSS are spot on - a good pump rep will consider your average & peak numbers with regard to inlet strainer, MOC, impeller design, seals and flush plan.

c. Your application is large enough that you are likely going to need a rail system for a submersible pump. A rail system provides means to raise & lower the pump and secure it during operation. As previously noted, the motor will be submersible rated, electrical cable & gland likewise, and submerged piping / pump outlet connection to same will be 'special' - read $.

d. When everything is considered, I'm not sure there will be a big difference in installed cost - find a good pump mfg. & rep - there are dozens & dozens of mfgs; probably fewer good reps in a given area. Maybe you could call around to local utility and industrial users to learn who has a good reputation - I'd try to talk to somebody in maintenance.

e. For a given pump & application, there will be a NPSHR - this is what will determine the elevation of the pump with respect to water level. NPSHR can be a 'given' (preselected), however this may have consequences in terms of pump size, rpm and overall efficiency. Did I mention find a good rep?

f. Once you have a couple of candidates consider pump efficiency, assuming somebody is paying for the electricity.

Good luck

Thank you for your very detailed reply. I will study your obseravtions further and see where improvements can be made.

Yes, we are using a rail system for lowering and raisng the pump.

Thank you for your very valuable contribution.

Flygt pumps are manufactured to easily run through the situation you described any other circumstance without a screening system and high abrasives/junk you would have to move to a "trash" pump and if worse a "shredder" pump which will take care of a work glove or a sneaker if need be. videos are on youtube. I work in the pump sealing systems industry and from experience if your company wants to foot the bill for Flygt that is the brand to go with both quality and ease to repair. any ITT/Xylem brand is the best, also your typical Hydromatic or Grundfos pumps offer models to handle this scenario also.

A bit off topic but...out of curiosity, how are you going to design the discharge piping fort the pump which goes up & down. Some sort of flexible adapterish hoses and stuff eh?

For example or this

A1) The answer comes from an analysis of the <...raw water...>, not from any forum. After all, one person's <...raw water...> is someone else's effluent.

A2) The range of <...TSS...> is 0-100%, though the type of pump that could be used at 100% would differ to that used at 0%.

A3) The only category that all of those could fall into is that of <...centrifugal pumps...>.

Do let the forum know the outcome of proper dialogue with pump suppliers. Telephone?