Hello, We currently have a submerged multi-stage centri pump ~60m down a borehole pumping water in underground (~5m below surface) tanks. The water has a high Iron content and as a result, bacteria have caused havoc with the resulting rusty slime reducing the throughput of the system. A lack of maintenance is mostly to blame for the drop in pumping capacity, and subsequent 'quick fixes' by the maintenance team have been ill-informed and have made my job somewhat more difficult.

I would like to replace the submerged pump with one mounted on the surface, for easy access by our mechanics. This would require a suction lift of ~60m. Is it possible to achieve this amount lift? even with manual priming?

My aim is to provide a solution of both an easily accessible pump which can deliver the water at a high velocity, to try to reduce the biofouling on the line. If a pump with ~60m of suction doesn't exist, can you think of another option?

Thanks

V

60m is too high for suction lift. The theoretical maximum suction lift is around 9m. Disinfect your borehole?

Chlorine/Hydrochloric acid completely ruins our product. I guess i'll replace the existing pump with a more powerful version and crack down on the maintenance team. Perhaps a Rapid sand filter or similar to remove the entrained sludge would be an option, at least then the downstream equipment will not suffer as much.

If the pump is at water level, do you really have a 60m lift? I thought lift is from water level up to pump. You would have to be concerned about pressure drop, system loss, in the 60m suction line. Figure the pressure drop for the flow rate you will want to determine pressure at the pump intake.

Ted

If one did exist, the pump would be on the surface and the water 60m below the surface.

Would agree that 60m is too high of a suction lift.

In addition, moving the pump motor to the surface is not going to stop the slime problem. In order to eliminate the slime problem, you will have to periodically disinfect the well. Some wells have the capability to feed chlorine into the well bottom continuously by installing a chlorine feed line attached to the well string.

Shock chlorination/hydrochloric acid treatment should be done only periodically, maybe annually. The well is flushed to waste after these treatments, so I don't understand why it should be affecting your process.

Addition of a multimedia filter will dramatically improve the water quality.

If you can't tolerate bleach then look at using hydrogen peroxide to disinfect the system. You will only be adding water.
Watch out though, it does not have any persistence.

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Plymouth Tube

60m not possible. 0 atm is absolute zero so max lift is one atm (or as 77 puts it roughly 9m or convert to whatever units you would like)