condenser tubes

[lordedmond]

some info please

I am building as a side project a triple expansion engine. I have to seal the condenser tubes into the tube plates which go on the ends of the condenser casting then the end cover go on


the tube plates will not pass through the casting


tubes are 1/4 od and the tube plate is 1/16   inches in both cases

I could soft solder them in but the TP could bend and fail to seal the vacuum ( water is in the tube ) to the casting

Any ideas


Stuart

[David Jupp]

Is it possible to arrange for one tune plate to 'float' to take up expansion/contraction?

A U tube arrangement with single tube plate wouldn't suffer this problem.

[lordedmond]

thanks for the reply

a floating TP would not seal the vac chamber

I could alter the design to have a u tube arrangement  but getting the bends in may be difficult


Thanks again for the input


Stuart

[David Jupp]

a floating TP would not seal the vac chamber

It would need a suitable seal - no idea if you have room for such.  I've known floating tube plates in heat exchangers sealed to hold significant pressures.

[lordedmond]

the answer is very little   

3 1/2 long  2 high and a inch deep

the 3 1/2 is the tube length and it is a two pass system the dwg shows the plates screwed with csk screws to the casting and the end casting bolted through into the casting , but there is no indiction as to the method of sealing.

in full size turbine condensers ( this is a triple expansion engine )  they are expanded into the steel TP and are made of brass tube


these are 1/4 copper in 1/16 TP

as there will be a vacuum out side the tubes and a small water pressure outside  , so the seal would have to stand about 10 psi


Stuart

[mgj]

O ring seals?

or make them a press fit and use Loctite 574 is it.(the orange sealant goop which seals everything.) the Loctite goes into
a shallow groove so its invisible.

[lordedmond]

thanks for the reply

to tight tube spacing for  O rings 

I will look into the goop

Stuart

[boatmadman]

How about make up a suitable taper plug and push into the tube end so the end expands onto the tube plate?

[mgj]

Is this a condenser like with a vacuum pump and all?

[lordedmond]

its the condenser for a triple expansion steam engine  it returns the waste steam to water and thus plus a vacuum to improve the efficiency of the final stage

the tube plates are a bit thin at 1.8 mm brass one end is ok as it can be done before assembly a drift could work in the other end though




Stuart