When A HERMS IS Born

[Aleman]

After the failure of my attempt to build a RIMS with a towel rail heater (They are made of temperature self limiting thermoplastic), and the conversion of the under back to have a kettle element in it . . . which worked but was a bit harsh. I decided it was time to bite the bullet and build an inferior HERMS system :lol:.

Having Acquired the Bits

TODO: List and cost Bits and Suppliers
5L Stainless Storage Container - Woolworths - 5 quid (It was during the last days of the company)
Cheapy corded Kettle - 7.99 from Morrisons . . . I used this one as it had long pins on the element, unlike some of the cheaper cordless ones that only have short pins.
10mm 6mm dia copper tube - BES . . . Coiled round a 2L PET Bottle . . . It needs to be reduced in height to fit it in, but I can do that when I have the fittings I need . . . 6mm to 15mm are not easy to find.

I thought that I had better put them all together . . . What I was after was a HERMS unit I could swap between the big and little brewery and make it 'self contained'. Using the IP56 box meant that all the electrics would be inside and not exposed . . . and as long as I seal all the holes with a suitable sealant it will retain the IP56 rating.

The first step was to decide on a position for the Heat Exchanger, and drill some holes for the studs that I was going to secure the Heat Exchanger to the lid of the box.

Turning the lid over and positioning it on the lid allowed me to mark the position of the holes on the Heat Exchanger, so I can drill them and braze in some studs.The studs are simply some 6mm stainless button headed bolts from aruncas that have been fitted through some very tight holes in the bottom of the storage container . . . I used a silver solder and flux from CuP Alloys.

The potassium fluroborate flux needs to be molten to work and this happens at about 575C . . so you are well above solder temps and need to use a MAPP gas torch . . . but the solder melts at just above 600C anyway . . . these are fairly small components so it is pretty easy to braze . . . Thicker steel and larger brass components are much harder as the heat is just absorbed. . . . They take a bit of cleaning up too

Using a Kettle element nicked from a cheapo kettle mounted in the base of the storage container so that I don't have to worry about the curve of the pot . . . plus it keeps the exposed terminals inside away from any liquid.

That's a 38mm hole, drilled with my new Bosch Cobalt Hole saws . . surprisingly easy, just take it slow and use a good cutting oil . . . with these very thin vessels it goes through easily . . . I would have preferred to use a QMax Punch but only had a 40mm which while usable was just too big to be reliable.

I also had to cut a suitable hole in the box lid to position the hole, that was fairly easy as it was just plastic and my big 64mm cheapo hole saw did the job.

You can also see that I have cut the holes for the PID Controller Auber Instruments and a Neon light to tell me when the element is 'on'. Despite me having the hole off centre (I have to make room for the outlet of the coil which will go into and out of the box), I managed to get the element pretty central in the storage container.

I suppose I should clean up the inside as well . . . when I dismantle it all to fit the coil is probably a good time. . . . Back to concentrating on the wiring . . .

Decided to fix the supply using a cable gland rather than any sort of socket . . . this means I can plug it into any spare socket. I've fitted the PID and Neon in place. The neon gets its feed from the wires that were originally connected to the kettle element. The 25A SSR is hiding on the left side . . . I will be cutting a big hole there to mount a BMF heatsink (with More Sealant required . . . Still silicone is good to 475C anyway . . .

As you can see I used the original lead supplied with the kettle . . . waste not want not.

I had a mate machine me some trick fittings to allow me to go from the 6mm tube to 15mm compression plumbing fittings. Drilled a 15mm hole in the side and base of the pot and silver soldered the brass fittings in place . . . . This wasn't easy as the brass conducts a surprising amount of heat . . . Given the amount of heat I had to use the metal of the container split when I was putting in the side fitting . . . luckily I had coated everything with the flux anyway so the silver solder flowed into the splits and sealed them . .. . Phew

Having got the fittings in place I then bent the arms of the coil and slotted them though the holes, and soldered them in using plumbers lead free solder . . . as it melts at 200C there was no danger of the silver solder being affected. Once cooled I trimmed the tube to length and cleaned and polished the end.

And here is the inside of the HE with the coil and the Element fitted back into place. Of course as I was fitting it back to the lid I needed to drill another hole in the lid to give me clearance for the outlet. . . plus another hole was needed to allow the plumbing to come back through . . . I sealed this with an IP66 Cable Gland.

With everything in place it was time to sort the plumbing out. A Brass compression T fitting 22-15-15 . . . was fitted to the outlet, and a 22mm Compression Blanking plate with a 3mm gland soldered to it, too the temperature probe.. The Copper tube passes through the Cable gland which seals it and returns the flow outside.

With all the wiring back in place, its time to seal up the lid

And here it is I'm proud to say . . . I have a HERMS . . . . This test was just using water pumped round the coil using the lovely little March May 809 HS pump . . . Can't wait to try it for real.

 

[EskiBrew]

Looking good Tony

 

[Vossy1]

Looks familair :hmm: :grin:
Looking good :thumb:
Was welding to the bottom of the container easy enough ? I was worried about burning through it.

 

[Aleman]

With my MAPP Torch and a fine jet the brazing was very straightforward . . . trick is to get an engineers fit between the two objects first . . as they were both 'small' they heated pretty quickly and evenly so the silver solder melted and flowed quite nicely . . . Plenty of the right flux helps as does knowing how to use it . . . took me some time

It could be a different story with the Brass bits I'm having made to take the coil in and out though as they are going to be 15mm brass :pray:

 

[Vossy1]

Cheers :thumb:

I decided it was time to bite the bullet and build an inferior HERMS system .

:lol: :lol: :lol: ...juts read that, was skim reading this am :P
I've been thinking for a while about trying to avoid drilling a hole for the HE element in a custom built table, you've just provided a solution :hmm:

 

[Aleman]

A ray of hope flitters in the sky
A shiny star lights up way up high
All across the land dawns a brand new morn
This comes to pass when a HERMS is born

 

[EskiBrew]

I like the way this is self contained. I reckon I will end up copying it when I get my HERMS together :thumb:

 

[Vossy1]

Great new pics A
When's the HERMS first brew day planned for ?
Just an observation, but have you thought about the potential risks of a leak from the kettle element/pot seal/compression fittings into the control box?
I get loads of condensation on my heat exchanger casing when starting it up from cold in winter or cold temps. The SSR looks pretty vunerable if a leak was sprung, or condensation entered the housing, it might be worth mounting the SSR on the underside of the lid.
Worth noting that quite a lot of water drips down the side of the container if you open the lid when it has condensation on it
Oh and don't allow the HE to boil, the lid will beconme opaque and change shape :whistle:

 

[Aleman]

have you thought about the potential risks of a leak from the kettle element/pot seal/compression fittings into the control box?

and

Worth noting that quite a lot of water drips down the side of the container if you open the lid when it has condensation on it

I have, and have really made sure the compression fittings are tight. I have also used IP55/66 fittings where possible for the wiring etc. The holes and base of the pot have been sealed with silicone sealant. Trial runs where I connected everything up to the mains water and let it flush through then closed off the outlet have shown that there were no leaks inside . . . Plus I then ran it at 80C using water recirc and the MM809 pump showed no leaks at high temperatures. So I am fairly sure there will be no leaks inside. . . Yeah I noticed that when I opened the lid the condensation ran all over the PID . . . so I removed the Lid and turned it though 90 degrees . . . I'm also going to seal around the PID for when that happens again :lol:

I get loads of condensation on my heat exchanger casing when starting it up from cold in winter or cold temps. The SSR looks pretty vunerable if a leak was sprung, or condensation entered the housing, it might be worth mounting the SSR on the underside of the lid.

I've actually cut another hole in the side of the box and mounted the SSR to a BMF heat sink on the outside by gluing the heat sink to the outside of the box. so the SSR is inside, heat sink outside, so its not sat on the floor of the box. . . . and I will drain down my HE chamber when not in use and fill it with hot water prior to starting which should eliminate any condensation .

When's the HERMS first brew day planned for ?

I have been hoping for some time this week when it hasn't been P*ssing down and blowing a gale . . . but it could be Sunday :pray: . I've been off work this week looking after the lad as his school decided to have two weeks for half term . . . Still it meant I could work on a few bits for the brewery, and clean up the FV from the Pilsner. . . . It was we doing that that I discovered that the pilsner may very well be for the drain :cry: :cry: I have discovered that the bottom fitting of the sight gauge had been weeping and letting beer build up in the insulation . . . as can be imagined this has turned into a slimy moldy mess . . . and explains that 'musty' taste I noticed when I racked it prior to lagering . . . I'm not happy. So I stripped the insulation, removed the old crappy sight gauge, and replaced it with some nice shiny ones in a 1/2" BSP version of yours . . . unfortunately my holes were bigger than 1/2" BSP so Food Grade Silicone sealant and some M22 Penny washers sorted that out ( I must admit that I would much rather have 1/2" BSP Threaded Penny Washers (40mm diameter). Just got to put some new insulation on . . . although I am contemplating fitting a Ball Valve just to make transfers easier :hmm:

And then I am fitting a sight gauge (In 1/2" BSP) to the HLT as well

 

[highwayman]

Fantastic Aleman.....A Brilliant job... well done :clap: I was really pleased with my new HERMS set up (which is almost finished) Until I saw yours :mrgreen:

I will post pics soon of my HERMS and new Gas brewery when I am fit again after the Hernia Op :thumb: I am looking forward to reading your posts on how the HERMS works for you Tony:thumb:

 

[Frisp]

Tissues ..... I need tissues.... lots of tissues........

 

[Springer]

Just found this one, all looks good to me. Too much for me to absorb at this time of night, especially when I have been sampling, more than sampling , my IPA and when question time is coming on :lol: So will be back tomorrow after a proper read, like the brazing bit, doing something similar myself on a copper set up, the gaps, or lack of them, are critical

 

[Vossy1]

Sounds like you've got all the angles covered A :thumb: and some nice upgrades going on to boot Sorry to hear about the Pilsner, not good :cry:

 

[Springer]

I have recovered from the IPA and just had a proper read, it looks a winner to me. As I am a bit late to get to Woolworths :lol: ,I am planning to braze up a copper cylinder unless anyone has any better/easier ideas.
I am no expert on these things but was planning to make my set up, all gravity feed down to the pump inlet, coil out the bottom that is, so that no wash water remains trapped, or will the pump scavenge the system dry ?

 

[Vossy1]

I am planning to braze up a copper cylinder unless anyone has any better/easier ideas.

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I am no expert on these things but was planning to make my set up, all gravity feed down to the pump inlet, coil out the bottom that is, so that no wash water remains trapped, or will the pump scavenge the system dry ?

TBH I don't think you'll ever get all the water out of the coil unless you oven bake it at the end of brewing (which some folk do, also with plate heat exchangers)
All the coils in my HE are orientated/angled downwards, as is the pipework in my HERMS. It all leads to a lowest point ball valve which is left open at the end of the brew day. TBH I don't need to do this anymore as this system is all stainless, but when I had a copper coil and pipework I didn't like the idea of leaving the copper pipework exposed to air and water.
You could always leave the pipework and coil flooded with sanitised/boiled water between uses

 

[Springer]

Fair comment vossy, you are keen on that stainless ................ and to be fair rightly so, its just the expense :) .
Don't have the kit to do this one, the TIG welder and the right gas.
I will have to talk to my man and see what's needed to braze ss, although I think I remember reading somewhere on the forum that brazed ss is not quite the thing. Is that down to sterilising ?

 

[Aleman]

I think I remember reading somewhere on the forum that brazed ss is not quite the thing. Is that down to sterilising ?

For coils and stuff it matters not. . . . If I could be bothered I would have bought a stainless coil from Manu and done pretty much exactly the same thing, Just brazed the coil into the pot using silver solder . . . The wort doesn't contact the Silver solder . . . All my thermometer/temperature probes in the FV are fittted into Stainless glands which are silver soldered into the pot and there is no issue

 

[Franklin]

Random thought (having just been giving my Plate chiller a recirculating clean via my HLT at 90c)

Could a Plate chiller & Temp controlled HLT with a couple of solar pumps be pushed into service as a HERMS?

 

[Aleman]

No too much risk of blocking the plates

 

[Franklin]