Keg Thumper2

[myles]

Previously I have used a 30 litre keg as a thumper by just fitting a vapour inlet into the top dome. We talked about this before Bushman.

Anyway I am doing another one for a client - this is going to be under a 3" SPP column fed from a 100 litre boiler. Well I have started preparing the keg, removed part of the top ring for access and gave a slight polish to the dome.

30 litre thumperHD.png

So I was thinking, any addition to the dome would spoil the appearance. So how about relocating the vapour inlet into the base. This thumper is going to have short height adjusters added to the lower ring to provide clearance for a drain, so a few inches more is not a big issue. We are all familiar with liebigs, so using the same principles it is possible to co-locate the vapour inlet with the drain.

Now in my case I am using a compression bulkhead fitting, but you could equally turn the keg upside down and use the existing keg neck - I would probably put a 3" connector on the other dome.

In this case however, I am thinking about a 1" drain with a central 1/2" feed into the vapour injector. Reducing the vapour inlet to 1/2" will increase the pressure and vapour speeds a bit - but in this application that is probably an advantage. I am thinking a row of 1/4" holes drilled in the vapour injector body. This will just be a 1/2" to 3/4" adaptor and a 3/4" end cap soldered together into a ball that will pass through the 1" bulkhead fitting.

keg thumper.png

Because this is for an offset column, I am going to incorporate an overflow back to the boiler, so this keg is going to be raised to the same height as the primary boiler. I think that I will also put this through the bottom dome, with its own connector. I did calculate how to use all 3 devices concentrically within 1 bigger fitting, but it was a bit untidy. A separate overflow connected through the base is no problem.

So what do you think. I know it is conventional to bring the vapour in through the top, but low level vapour injectors also work. Can you think of any issues to prevent this working? Obviously the vapour path does need to have a high point higher than the top of the thumper - but it would have this anyway in most boiler / thumper configurations.