Heat exchangers and combi boiler - anyone been here before ?

[Springer]

Hi all,
don't know if I am wasting my time on this one, so I will throw it to the experts.
Came by a combi boiler in a mates through out pile and opened it up to find the following. Thought I might find something useful, as a combi is a heat exchanger, but I think it is better than I imagined ?? Needed a bit of "technique" to extract but now know how to deal with this particular model !!
I have included a pint of my Scottish heavy so that you can get a feel of the size of this beast. I take it you all know the size of a pint glass !! :lol:

The coils are fairly tight and springy, but they can be wedged apart, that's the purpose of the bits of plywood, which could be replaced by something more suitable if the coil is ok. The fitting that go over the o ring outlets even have a tapping for a temp. probe ...tasty !!
Tell me if I have missed something but I think it will make "quite" a heat exchanger for a herms set up, might be too big, ........someone said get as much "pipe" in as you can !! ??
The pump in the boiler looks very interesting, but have not had time to extract it yet, plastic, used to only mains water, continuous running, high temperatures and free
What's the thoughts
Best regards
Springer

 

[brewzone]

My first thoughts are

a) is it made of stainless steel?

And

b) are the coils full of some sort of deposit?

If the answers are a) Yes and b) No then that looks a very interesting solution to a rims/herms system.

BZ

 

[Springer]

Looks like stainless to me....... what else would they make if from ? It not copper or steel !
Probably has some deposits, must have after several year use, easy to sort with a dose of calgon if the adverts are to be believed !!!!........or something similar .

Its one hell of a surface area.......... Compared to other exchangers seen on the forum, this is the big daddy......... :)
Springer

 

[Vossy1]

Is the answer stamped on the coils?
If not, can't you track the info from the boiler model and make?
Looks quite interesting :hmm:
See if a magnet sticks to it?

 

[tubby_shaw]

See if a magnet sticks to it?

Remember people Austenitic stainless steels such as 18:8 do not attract magnets :ugeek:

 

[Springer]

Thanks for the replies. I have looked on the manufactures site (good idea) and the current models have a ss heat exchanger and they do look very similar to my scrapper. The writing on the coils is real gobbledegook. I tried a magnet and it was only slightly attracted, no way like it picked up our best stainless cutlery does ! ? I think it will be fine for brewery use.
The comment about the deposits is a fair point, it aint half heavy, could be lots of stainless or mank. I think its lots of stainless cos the thing had the flame bashing at it for long periods in the center, so needs a bit of pudding in it !! Modern combies are around 30 kw and older ones were probably over 20 kws that a lot of heat being thrown about in a fairly small unit. Either way a dose of fernox and then calcom should sort that ?
So down to use. Looked at your exchanger Vossy and it looks like 10 coils of 10 mm copper at 100mm diameter. If my maths are correct that about 100,000 sq mm of surface area, the combi thing has about 10 times as much !
So assuming your exchanger works well, do I need any more than 100,000 sq mm ?
Would this thing make a good wort cooler for my 15 gallon plant? Should I pump beer through it or use it as an immersion ?
I have managed to extract the pump from the boiler and it looks promising, should this be a separate thread.
Many thanks for help
Springer

 

[Vossy1]

So down to use. Looked at your exchanger Vossy and it looks like 10 coils of 10 mm copper at 100mm diameter. If my maths are correct that about 100,000 sq mm of surface area,

TBH Springer my initial design was just a punt, no real thought went into the heat exchange surface area.

So assuming your exchanger works well, do I need any more than 100,000 sq mm ?

Mine does work well for my needs. I recirc my runnings at about 2-3ltr/min, though I have gone up to 5ltr/min without problems. The question of surface area depends to some extent on flow rate.

Would this thing make a good wort cooler for my 15 gallon plant? Should I pump beer through it or use it as an immersion ?

I think you'd have to use it as an immersion. Making it into a cfc could be difficult due to its shape. If used as an immersion cooler you could always aggitate the beer by using a pump to create a whirlpool in the copper.
Only one way to find out...give it a go !

 

[Springer]

Thanks very much for the reply Vossy.
I think I will copy your exchanger, was my interpretation of sizes about right? I can then use the combi exchanger as you mentioned. It can always be adapted later if I want to go more sophisticated ! When I have some hot water to hand I will immerse it in a cold water bath and pump through it, to check out its cooling capability. It certainly is a big un!!

 

[Vossy1]

Hi Springer, the sizes were about right. If you look here you can see the exact size much more clearly. The original copper coil had 10 coils as you said :thumb:
FWIW, Manu made my stainless coil and shipped it for little more than the price of a 10m roll of 10mm copper coil

 

[Springer]

Thanks for info........ once again.
I have quite a bit of kit to buy at moment so will stay with copper to your dimensions. I have come by a free :), again, copper water cylinder. Plan is to cut it up and solder up a tank for the herms heat exchanger with 10mm tube inside. Yes I have abandoned the gravity plan and am going for it, herms here I come :)
Still pondering whether to install a domestic hot water set up, we are getting a combi fitted to house so, stuff going spare, or fit my 99p ebay, big boy heat source.
Do you know if those pids on ebay at 35 quid with a ssr ok.

 

[Vossy1]

Really looking forward to seeing a copper brewery if you get it up and running S ...to my mind copper shiny is a lot more attractive than ss shiny...shame no one really makes them easily affordable...and I expect to be punished for that comment :P

Do you know if those pids on ebay at 35 quid with a ssr ok.

Can't really comment without the link :hmm:
Auberins is hard to beat, their service is great....in my case 4 days delivery A few on the forum have used them, and can testify to their service

 

[Aleman]

I've bought several of the Chinese eBay PIDS and SSR's and they seem fine to me . . . although I prefer the ones I bought from Auber though

 

[Springer]

Thanks Aleman / Vossy
Hear what you say, the Chinese manual was not as easy to understand to me, but not a problem, cos a mate will be drafted in for the electrical bit, I'm welder, saw and hammer :)

My plan is only for a heat exchanger in copper, but will then lag it to help save the planet :)

Talking copper and things how about these http://hbd.org/brewniversity/engineering/conical/ wow ..........no not the copper thing just managed to insert a link

Could I ask how do you do that copying the bits of previous posts thing by the way ? :?

 

[Vossy1]

Could I ask how do you do that copying the bits of previous posts thing by the way ?

At the top of your reply box is a button marked quote. Click on it and this will appear in your text box [.quote][/quote]. Copy the text from the post you want to copy and insert it between the quote boxes ie, [.quote]text here[/quote], that's it.

Note, I have included a dot in the quote boxes above to allow the set of tags to be visable, it will not appear normally.

 

[Springer]

At the top of your reply box is a button marked quote. Click on it and this will appear in your text box

Like that then ?

Vossy, you are a source of knowledge thanks very much. :)

Off to the tub now, been out working one of the spaniels all day, both of us are cream crackered, lots of pheasant are worse , will be in bed early and hopefully up early tomorrow to do another brew of Scottish Light, with only 1/4 tablet of Protacfloc this time !!

 

[Vossy1]

Vossy, you are a source of knowledge thanks very much.

Not that good though, I still don't know how to attribute a quote to a person :lol:

 

[Wez]

[.quote="vossy1"]users text[/quote]

:thumb:

(remove "." as per V's previous post)

You can have fun with it too:

Not that good though, I still don't know how to attribute a quote to a person

 

[commsbiff]

or, if you want to qoute from a particular post, just hit the 'quote' button on the bottom right of that person's post. Then delete the bits you don't want.

 

[Vossy1]

:lol: :thumb:

 

[pjbiker]

Hi, when I saw the CC heat exchangers sold to the homebrewer for about £100 I thought, thats exactly the same design as I'd seen inside my combi boiler, and had similar thoughts to you. Unfortunately, (well, fortunately) my combi boiler is working fine and don't plan to start removing bits . I made a CC the 'conventional' way with the 10m ? of 10mm copper microbore and hosepipe. It is perfectly adequate at cooling but the flow rate using gravity from my 70L is too slow, takes about an hour to collect 53L. If you manage to bodge a pump into your system you'll be lauging :lol: . Personally I can't be arsed at present, a future project. Would like to see how you get on with it.
PJ