I've seen a lot of cent. pumps but never one with an intake arranged like that one!!

Great illustration…

Pete

The centrifugal pump on the Easton, Amos & Sons drainage machine has a double entry. The pump shaft is vertical and the intakes to the pump are set as low as possible. At low water levels the top intake duct is a syphon.

JA

Edit: see http://www.wzlet.org

Edited By JA on 09/03/2017 19:29:47

What many people may not appreciate is that even now you can usually find a steam up and downer stripping pump and steam turbine driven cargo pumps in many petroleum tankers. I'm talking ships here, not trucks. Double inlet pumps are the norm in large sizes. They aid throughput and balance axial forces. As for the use of steam, steam stripping pumps are safe in a potentially hazardous environment where you don't want electricity. Cargo pumps usually have their prime mover outside the pump room, in the engine room. Steam turbines are often used because that puts load on the boilers to produce plenty of inert gas for blanketing the cargo tanks as cargo is discharged. Electric drives can be used but then you may need a separate inert gas generator.

Reg

Hi, I used to maintain centrifugal pumps with this type of intake back in the early 1970's. They were made by a company called Uniglide, who are still making pumps I believe, they were similar to the ones in the illustration below and were driving by an electric motor, like the one in the middle.

I can't remember working on any Gwynnes pumps myself, but the Uniglide ones were all replaced by the beginning of the 80's, mostly by submersible ones as they suited the companies needs and needed less maintenance was required. The Uniglide's did however shift huge amounts of water and had bronze impellors and they were all 6 inch.

Regards Nick.

Edited By Nicholas Farr on 09/03/2017 21:40:56

OK, now you've gone and confused me even more…. the steam pump. Why are there two steam ports for each end of the engine??? I've never seen that before!

Thanks,

Pete

Two steam ports, one inlet, one exhaust. The outer ones are the inlets and inners the exhaust (exhaust goes to cavity under the valve, inlet is exposed by the valve to the steam chest).

Paul.

Thank you Paul and Duncan! As soon as I read "…to cushion the piston." it was one of those 'duh slap the forehead' moments. That feature prevents knocking the heads off with a flying piston!

Another learning moment brought to me by this Model Engineer Board.

Pete