25gal ss boiler build + immersion heater - pics

[Trunky]

[Kev888]

I am really deeply impressed by your build, well done!

Thanks, thats very kind!

Whilst I've contributed bits and bobs that are original, I'm definately standing on the shoulders of giants - whoever built the tank in the first place did a good job, and many of the ideas for converting it came from this most excellent forum.

Cheers,
kev

[Kev888]

Well, I'm very pleased to report success!! Its only water for the moment but I've currently got a comfortably vigorous boil going - in fact I'm a little concerned that with wort to maintain the froth more it could be too vigorous, but we'll see. Sorry Dave, no big bangs - yet, anyway.

It took about four hours and 20 mins to get 113L of water from 20 celcius to the rolling boil, so not too many losses then - clearly the insulation and small lid is working. More importantly it'll get from the sparge runnings to the rolling boil in about an hour and a half or so; in fact as I'll be fly sparging, if I start once the element is covered and begin whilst the sparge is still under way it won't be long at all after the sparge. That is a relief - if I'm patient one element is definately going to be enough.

I took some temperature readings every half hour - as you can see, its at worst just a few degrees below theoretical optimum (the top line is the theoretical one):


I may regret the small 6" diameter access hole when it comes to cleaning, but I'm vary happy with it for the boil. I left a metal plate loosely covering the opening and very little steam escaped until the water was actually boiling; the test I did with my HLT with no lid on caused no end of vapour to condense around the kitchen well before boiling was reached. I was also pleased to find that after four hours the plug was only very gently warm to the touch, by no means hot. Result!

Time for another celebratory Pint, I think.

Cheers
kev

PS Haz, I couldn't see the braid strainer once boiling began unfortunately so couldn't tell if it floated at all- too much gas/steam in the water. But I switched the element off and as soon as things cleared it could be seen sitting on the bottom as before. I guess it could be different with hops and with gas heating, but you'd think a stainless braid would settle faster than they would

[WishboneBrewery]

That looks blooming good
I use two kettle elements in my HLT to get to 81c then turn the direct wired one off and leave it to tick over on the Temp control on the other element, I vaguely timed it heating up the other day and it heated quicker than the water heating calculator on my phone predicted. so 44 Litres of water to 81c in approx 40mins Starting at 20c.
I need to Insulate my HLT sometime as its bound to stop the temp control kicking in as often.

[Kev888]

Yes, quite a relief.
I was considering two elements but didn't want to make more holes than necessary or strain the electrics too much, so thought i'd first try to make it efficient and minimise the need for power with all the insulation. I can't expect faster than the theoretical heating time so it will always take a while with one element and that sort of volume, but the insulation and top/lid stops it taking much longer than it has to and seems good at helping to create a vigorous rolling boil.

There are more powerful industrial immersions available for the same fitting so it would be quite easy to upgrade without more holes, though I'd then need some sort of regulation to stop the boil being excessive and the wiring wouldn't be your standard 13A plug and so on. So for now I think I'm happy - it takes a while to boil a full tank from scratch, but shouldn't take 'too' long to bring the warmer sparge to the boil hopefully.

Cheers
Kev

[sparky Paul]

The single immersion heater solution looks good to me, especially after adding insulation.

Bear in mind that you should be pumping in 3KW - the nominal voltage in the UK is still 240V, despite what the eurocrats tell you it should be!

[Kev888]

The single immersion heater solution looks good to me, especially after adding insulation.

Bear in mind that you should be pumping in 3KW - the nominal voltage in the UK is still 240V, despite what the eurocrats tell you it should be!

Yes its what I was hoping really, I've had good luck with smaller quantities and the one element but this was the first time with this much volume. I figure its easier to control one element, doesn't load the electrics so much and/or could let me run the boiler and HLT at the same time if I wanted to. It certainly works, the only thing is of course it taking longer to get there, but by starting the boiler once the fly sparge has covered the element the time to boil should be acceptible even on 100L batches really.

I measured the voltage here fairly often over the years for one reason or another, and it certainly seems that the nominal numbers are fairly loose - sometimes its been almost down to 220 and up as far as 246v but it does usually seem to be well over 230 just as you say. I once saw a definition of the word 'nominal' that essentially said 'meaningless'

Cheers
kev

[leedsbrew]

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[Kev888]

Just a quick footnote:

Although BigDave's 'bang!!!' happily didn't happen during testing, I have now replaced the connector block in my immersion heater with the ceramic sort. The 1-way ones were out of stock so i cut 3-way in half with a tile-cutting blade in my angle grinder. The old plastic connector wasn't the melted-wax effect I'd half expected, but it showed some signs of having been a little warm so for regular use I'm glad that its been changed. The cable is already the proper heat-rated 16A stuff suitable for use with domestic immersion heaters.


Immersion heaters like this aren't usually supposed to be covered (apart from by the cap, not shown in the pic) and yet aren't water proof, so I'm also going to make an overhang positioned over/above the element (without restricting air flow to it) to shed any water drips safely out of harms way.

Cheers
kev

[Kev888]

Well after using the boiler for several months I decided to cut the top off. Its a shame to partly destroy such a well made tank, and I'll need to sort out a new means of steam extraction from the garage before next winter, but on ballance I think (I hope) its worth it. The access was getting too annoying - mainly for cleaning but also skimming crud off and so on, and having to use a torch to see whats what.

Here it is with the top off, and also with the paella pan lid I found (on ebay) to fit it. Its only Alu and very thin indeed, and not exactly tight fitting against my slightly irregularly cut rim (had to leave a small bit of the shoulder to fit the lid so was a bit tricky). But it was cheap and the service very good and i think it should do the job (I almost never fully closed the boiler before anyway):

After cutting off the top I had to lay the tank on its side and bounce up and down vigorously on the rim to make its top cylindrical (rather than oval) - I very nearly wasn't heavy enough!

And here's what it was all for - Ahhh, at last, I can see in, I can reach in, and if I want to both at the same time!


It should also give me the opportunity for a design of hop stopper which won't necessarily fit through a 6" hole, too. The braid has largely worked well but the drain-off stuck last brew day so clearly isn't perfect. i may want to use pellets sometimes too so maybe some sort of mesh may be on the cards.

Cheers
Kev