built in centrfugal pumps of medium speed diesels

[shipvibration]

hypothetical Q: If a centrifugal p/p driven by the engine (or any type of P/p)is fitted for fresh water cooling duties, how will it function when the engine is reversed?
any ideas will help..
tvm

 

[harrisj]

It won't work!

Of course, the engine is not usually reversed - the transmission does this in most applications.

 

[BillSalvage]

Large reversible medium speed diesels use independent fresh, sea water and lubricating oil pumps. As far as i have even seen engine driven pumps are only used on vessels' with reversing geasrboxes or control pitrch propellers.

Hope that this helps.

Bill Salavge

 

[aircraftengr]

I was just wondering, how does it affect the fuel transfer pumps? I know we're talking about coolants here, but does the fuel transfer flow have to be modified?

 

[GreenRichie]

On large reversible marine diesel engines there is often a gear pump for LO which operates in either direction with the flow from the sump tank to the bearings directed by non return valves fitted in the suction/discharge of the pump. It is a very simple system but hard to put into words. does anyone know how to attach a drawing to these messages?

Cooling pumps on all large marine diesels are normally independently driven because they are used to keep the engine warm by circulating heated water when the engine is at rest but if this were not an issue the same system could be used as for the LO pumps.

Fuel transfer pumps in this case are electrically driven pumps used to transfer fuel from storage tanks to service tanks. Circulating and supply pumps are independent because they have to keep the Heavy fuel oil circulating and warm
(it solidifies if cold) and the injection pumps are cam driven from a reversible camshaft.

hope this helps

Richie