Pump layout and mechanical handling
Pump layout and mechanical handling
(OP)
4 of the proposed pump stations we are proposing don't seem to be right to me.
We have a horizontally split case pump where the drive shaft is vertical but the impeller is horizontal.
The inlet and outlet are horizontal and are 700 and 400 pipe size respectively. The actual inlet and discharge pipelines are 800 and 700 using reducers. The motors are betweeen 1.2 and 2.1 MW so are in the region of 8000 kg each. The pump is 4000 kg.
The arrangement is that the pump is on a plinth in the basement and the motor is sat on the floor above which is something like 5m above the pump floor level. A short approximately 2.5m shaft connects the motor to pump.
So, to remove the pump, the pump is 'hidden' beneath the motor support floor (reinforced concrete) and what has been proposed by others is that a separate mobile crane is lowered into the basement for maintenance of each of the 9 pumps. But the mobile crane does seem very mobile as it is a large structure that has to be rated at 1.5 times the mass of the pump i.e. 6000 kg.
It must also be power driven.
It somehow seems a better idea to either remove the motor above and allow room for the pump below to be reached by the crane hook or that the motor is also on the pump floor with the pump having a horizontally orientated shaft rather than vertical. There would be no need for a floor above and the crane would have direct access.
Any thoughts on this I would be most grateful.
Regards
John
We have a horizontally split case pump where the drive shaft is vertical but the impeller is horizontal.
The inlet and outlet are horizontal and are 700 and 400 pipe size respectively. The actual inlet and discharge pipelines are 800 and 700 using reducers. The motors are betweeen 1.2 and 2.1 MW so are in the region of 8000 kg each. The pump is 4000 kg.
The arrangement is that the pump is on a plinth in the basement and the motor is sat on the floor above which is something like 5m above the pump floor level. A short approximately 2.5m shaft connects the motor to pump.
So, to remove the pump, the pump is 'hidden' beneath the motor support floor (reinforced concrete) and what has been proposed by others is that a separate mobile crane is lowered into the basement for maintenance of each of the 9 pumps. But the mobile crane does seem very mobile as it is a large structure that has to be rated at 1.5 times the mass of the pump i.e. 6000 kg.
It must also be power driven.
It somehow seems a better idea to either remove the motor above and allow room for the pump below to be reached by the crane hook or that the motor is also on the pump floor with the pump having a horizontally orientated shaft rather than vertical. There would be no need for a floor above and the crane would have direct access.
Any thoughts on this I would be most grateful.
Regards
John





RE: Pump layout and mechanical handling
- There is a permanent bridge crane on the main floor
- The pump motor sits on the main floor
- The main floor supports the motor
- Openings in the main floor allows the pump and the motor to be connected by a shaft
- The pump sits directly underneath the pump motor in the floor below
Assume the pump and motor is already installed:RE: Pump layout and mechanical handling
The 5 points you simplify are correct. Only slight alteration in that the motor is not on a 'main floor' at present. The pump is on the floor and some kind of intermediate reinforced floor to support the motor is above it. Of course it only has a small hole in it for the shaft!!
this intermediate floor has had me question a few weeks ago that there is not enough mass in it. I'm not a civil engineer, but mechanically I have asked the motor supplier for full installation details and loading etc.
The bullet points you made reflect my thoughts exactly. I did a large pumping station recently and that is exactly how the pumps were removed. And as you stated, the pump casing remains in-situ and all the insides can be pulled up through the motor spigot location hole.
The pump motor was placed on a local 'stool' nearby allowing the motor to remain vertical.
This seems like standard procedure to me QualityTime. Will do. my best to have this looked at in more detail.
Many thanks again for excellent post.
Regards
John
RE: Pump layout and mechanical handling
- The upper pump casing is removed by use of the bridge crane and set to the side at the pump level.
- The bridge crane then lifts out the impellor and sits it on a manual assembly at the pump level.
- The bridge crane at this point is uncoupled from the impellor.
- The impellor is then usually manually moved to a location where there is a free and clear access opening up to the first floor.
- The bridge crane shackle is dropped to the pump level to hoist the impellor onto the first floor and moved to the loading bay.
Sometimes, when they cannot fit the overhead bridge crane shackle through the motor shaft opening they attach cloth sling belts to the shackle and thread it through the shaft opening. Or somtimes they attach a smaller shackle to the bigger shackle so that the smaller shackle goes through the opening. Just make sure the motor shaft opening in the floor is of ample size.RE: Pump layout and mechanical handling
It just so happenned at the Liverpool Wastewater treatment works Puming station, we could pull all the internals up through the steel plate which was supporting the 500 kw motor.
But this current project is a different arrangement and pump.
Will check the size and mass of the impeller etc and propose an alternative (if viable).
Thanks again.
RE: Pump layout and mechanical handling
RE: Pump layout and mechanical handling
Its 2.6m high plus we have 50mm cooling water supply piping....
RE: Pump layout and mechanical handling
RE: Pump layout and mechanical handling
RE: Pump layout and mechanical handling
RE: Pump layout and mechanical handling
RE: Pump layout and mechanical handling
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Pump layout and mechanical handling