What Ive been doing all week

[paulmowers]

This is why I didn't have time to make my own welding trolley.
Its a 600 litre accumulator tank for a solid fuel boiler installation, complete with boiler charging coil, and solar charging coil, built from 3mm plate with 25 25 3 angle corners and braces. Welded entirely with 6013 rods, 10kg of the bleeders.
glad its done!!!
hydraulic test tomorrow, fill it first and check for leaks, then probably 5 - 10psi and see what happens, as it will be working at max of 15psi, I think a safe test would be 30psi.
here is the beast..

 

[wyn]

Blimey !... loads of pipe connections there.

Does it it have lots of pipework type stuff inside.

 

[paulmowers]

Hi Wyn

Yes it does, theres the boiler coil which ammounts to about 13m of 22mm copper,expensive and the solar coil is 10m of 15mm copper.
so that takes care of 4 connections.
Then there is a fill/drain and a vent.
rads out and return, and dhw coil in and out, oh yes and the one dead centre is a hollow tube for a temp sensor.
Thats about it really.

Paul..

 

[jugs]

This is why I didn't have time to make my own welding trolley.
Its a 600 litre accumulator tank for a solid fuel boiler installation, complete with boiler charging coil, and solar charging coil, built from 3mm plate with 25 25 3 angle corners and braces. Welded entirely with 6013 rods, 10kg of the bleeders.
glad its done!!!
hydraulic test tomorrow, fill it first and check for leaks, then probably 5 - 10psi and see what happens, as it will be working at max of 15psi, I think a safe test would be 30psi.
here is the beast..

Paul
I cant see any evidence of internal stays at 15 psi the flat plates will bulge

 

[snowcat]

double working pressure was the norm for a new build on the last boiler test I was involved in, I know the regs have changed now but you wont go far doing a hydraulic on that calc, always the joint you can no longer get to that weeps on a test!!!!

 

[jon-eastanglia]

Good job there, looks interesting, this is similar to what i am planning. I am building a large half circle enclosed fireplace with wood burning oven at the top, i plan to have two radiator type things/ or coils in the top of each joined to the same loop to heat two heating loops, one for the hot taps around the house and one for the radiators. The radiators would be circulated by a converted piston type pump, and i guess the same for the hot taps. Any pictures or guidance for the heating coil that goes in the fire?

 

[paulmowers]

Hi All

I cant see any evidence of internal stays at 15 psi the flat plates will bulge

You are quite right jugs they will, had a rethink since the post last night and decided as its only gravity fed from about 5ft above, the 15psi wp was a bit high to say the least, so have gone for a 10psi pressure test which resulted in only 3 small weeps and a slight bulge on the plates, so fairly happy

Any pictures or guidance for the heating coil that goes in the fire?

Sorry no, mainly as I purchased a rojek 25kw wood boiler to do that bit for me, decided the challenge of building the accumulator tank was enough for a start.

cheers paul..

 

[jugs]

Hi All

You are quite right jugs they will, had a rethink since the post last night and decided as its only gravity fed from about 5ft above, the 15psi wp was a bit high to say the least, so have gone for a 10psi test which resulted in only 3 small weeps and a slight bulge on the plates, so fairly happy

cheers paul..

pressure from standing head of water = 1/2 psi /ft,
mesure from bottom of your unit to top of header tank.

To stay that unit, drill 8mm hole near center of each plate, cut 8mm rod 1/2" longer than OD of tank, poke rod thro holes, cap weld, job done.

PS Tank must have an open vent.

(teaching granny egg sucking )

Looks like big job

 

[storm monkey]

I'm looking at fitting an accumulator to the farm and hadn't thought of making one. How are you going to insulate it? Obviously this will make or break the effectiveness of the installation. Are the heat exchangers basic copper pipe, or have you added fins?

Looks an interesting project. I await further details with baited breath!

Phil

 

[paulmowers]

Hi All

pressure from standing head of water = 1/2 psi /ft,
mesure from bottom of your unit to top of header tank.

To stay that unit, drill 8mm hole near center of each plate, cut 8mm rod 1/2" longer than OD of tank, poke rod thro holes, cap weld, job done.

PS Tank must have an open vent.

I thought it must be around that figure but wasn't sure, kind of estimated gueswork. Decided not to chance the drilling and rod method of fitting stays internally due to the danger of hitting the coils on the way through, but fitted 3 more sets of braces around the tank instead today, did another test to 15psi, as the header is 12ft above base of acc tank and about 1ft deep so should be wp of 6.5 / 7psi max, and yes it is open vented.
Should have fitted the stays internally when the pipes were all fitted to the front panel, before welding the sides and top on, would have been so much easier, oh the wonder of hindsight!!!

Thanks for the advice Jugs, much apreciated.

I'm looking at fitting an accumulator to the farm and hadn't thought of making one. How are you going to insulate it? Obviously this will make or break the effectiveness of the installation. Are the heat exchangers basic copper pipe, or have you added fins?

The tank itself has to fit in an alcove beside an old fireplace, the fireplace has been taken out and that is where the boiler will be, so this is the main reason for building it. 1. so I can get the largest size possible into the space available, and 2. its a lot cheaper than a manufactured one, provided you discount the time involved!!
The heat exchanger for the boiler is 22mm plain copper, which makes a slow downward spiral with elbows at each corner, so its a kind of square coil if you get what i mean, this is to pack as much pipe into the square hole as possible for maximum heat loss to the water in the tank, I managed to fit 13metres in there.
The solar coil is 10 x 1m lengths of 15mm copper (plain) fitted to 2 U pipes connected to all 10 uprights top and bottom, reasoning being if I have enough area for the fluid to flow through it will slow it enough to give up its heat, don't know if thats sound science or not but seemed logical to me.
Insulation, not sure what to use yet, but as it will have a 3" gap to the walls on 3 sides was thinking of that horrid fibreglass rockwool stuff as I can pack as much of that in as it will take, same underneath with the tank standing on 2 bits of 3" x 3" timber, finally building a timber frame top and front to hold the insulation in on those sides.

Paul..

 

[jugs]

Hi All


Insulation, not sure what to use yet, but as it will have a 3" gap to the walls on 3 sides was thinking of that horrid fibreglass rockwool stuff as I can pack as much of that in as it will take, same underneath with the tank standing on 2 bits of 3" x 3" timber, finally building a timber frame top and front to hold the insulation in on those sides.

Paul..

Hi paul

For front & top insulation, use polysterene sheet 8'x4' x 1,2 or 3" thick from builders yard. 'Kingspan' is better but expensive.

Are you fitting a diferental temperature valve to stop heat loss thro solar colector.

keep us informed on progress

 

[paulmowers]

Hi Jugs

Polysterene sheet, yeah good idea, no mess and I can cut it with a hot wire if I'm thinking of the right stuff, should be a nice looking installation with that.
RE the solar coil, its a bit of an in the future thing at the moment, main aim is to get the boiler in and working and get some heat into the house, apart from our open fire in the front room!! Decided to fit the coil now as it would mean major rework or even impossibility to fit it retrospectively, but to answer your question yes I will have to fit something to stop the tank losing heat to the panels at night and in dingy or cold weather.

Paul..

 

[runnach]

Interesting project Paul and, neat bit o fab/welding, however, I'm trying to get my head round to why you did not manu in stainless??? I know matl costs would be greater, but considering maintenance free, well worth the extra £££'s, that's if you intend to stay put where you are for a considerable period of time?

Sorry, just me looking at the bigger picture.

Cheers.............

 

[MrFluffy]

Paul, google for a Resol deltasol solar controller, it basically monitors a thermocouple on your panels, and a thermocouple on the tank, and when the temperature of the panels is +5deg or whatever you set it to, it turns on the solar circulation pump.
They do two variants, the more expensive has a connection for datalogging when the pump is running. I can recommend them heartily because I have one on my other house, and its worked flawlessly for 6 years now. The pump blocks the thermosyphon flow normally. You could diy a homebrew one but if it fails in mid summer you will boil the panels. We had a closed circulation loop with expansion vessel, 3 bar safety blow offs and filled it with fernox antifreeze.
Theres a company called Dedicated pressure systems, that make what youve diy'd here commercially, they have flat multi plate heat exchangers (whcih you can buy seperatly) that they will fit to a multi coiled thermal store they call a heatbank. They fit a flow sensor to the water pipe, and heat the hot water on demand instantly via the heat exchanger and a circulation pump controlled by the flow sensor, so no stored water etc, but piping hot at the taps, full mains pressure. Last time I had solar coils, ufh coils, a big 3 phase immersion heater, and a seperate boiler coil so I could retrofit a oil boiler as a heat source later. The tank was insulated at manufacture with close density foam and a sheet steel jacket over the lot, with a plasticised finish. Very durable....
I have a heatbank 500 on my last property, Im quite happy with it and plan to just go with the same again, but you might pick up some tips from their website or ideas.
http://www.heatweb.com/

You can get kinspan quite reasonably in the uk from sheffield insulation. Who have branches all over the uk. We stuck 100m2 of it in the last place, id love to come over and fill the van with it for the new house but funds dictate we have to use plain old polystyrene insulation.
http://www.sheffins.co.uk/contact.asp

 

[paulmowers]

Hi guys.

Thanks for the coments Runnach, why not stainless? Basically never done any stainless work except a bit of work on a fruit packer, during the work produced a bit of metal dust and came down with a really nasty rash, docs reckon it was something in the metal, If I'm right I think stainless is steel alloyed with chrome or something similar so guess I have an alergy to it, anyway Ive avoided it ever since.
Before building from steel I did a lot of research on the green building forum and navitron and apparently rust shouldn't be a problem on the inside as once the initial fill of water is heated the oxygen in the water is released into hydrogen I think and once thats happened as no more fresh water enters the system there is no oxygen in the water to allow rusting to take place. The outside is taken care of by several coats of paint, doing that next.

Thanks for all the info mr fluffy, always good to get advice from someone who has a similar setup working.

cheers paul.

 

[snowcat]

on the commercial builds a ceramic fibre and aluminum wrap is the norm, sometimes with a double wrap containing aluminum foil as well as the outer aluminum wrap, a good wrap is essential to the efficacy of any boiler......

 

[kingkay]

Hello there, first post on the forum and a bit off what I came here looking for but at least it something I understand!

By trade I am a heating engineer and spend lots of time cleaning out sludge from heating systems, especially thermal store systems. Generaly on a smaller scale - 150 200 litres - they work the same way as your set up but with less heat sources (usually). Anything open vented can pull in air, sealed systems can get problems with muck too but its not as common/severe. Ive been told all sorts of reasons for this such as poor system design or chemical reaction between differing metals. Whatever the reasoning I do deal with the results on a weekly basis. Im sure you've done your research but make sure you flush the system very thoroughly (hot and cold) and dont skimp on the inhibitor you'll need loads due to the system volume.

Looks great - loads more fun than a trolly!