Resurrection of a CFEI 100 KVA Induction Furnace

[awemawson]

A bit of a scrappy day today - odds & sods. I had to make room to cut the slot in the concrete, which involved moving the large blue plastic barrels of glycol solution that I've been keeping for re-use all this time - trouble was that pallet had rotted and by heck they are heavy to shift onto new pallets. This is the second time in thirteen years that they've been re-palleted !

Also went hunting for shuttering timber for the small slab for the pump dog house - found some scaffold tower boards with rotten ends that will still be long enough when trimmed.

Then I redrew and cut a replacement 'bottom shelf' for the new chiller. I've never been happy with the fit of the old one. Now is the time to sort it as I'm about to make the fixings for the tank, and bolt the motor down. So sort it or put up with it! The frame is not exactly square so I had left a rather large wiggle space where the notches for the frame uprights are. Well today I experimented with a very large and stout sash cramp that I have to see if I could pull the frame square - yes I could although of course it springs back without the clamp. A bit of 'over squashing' improved things - better but not perfect. So I drew up another base with only 1 mm excess space for the uprights. It went in slightly reluctantly and is holding the frame square. Twelve M8 bolts later and it's fixed down

All will need  dismantling for painting but at least now it looks OK to put my name to!

[awemawson]

So my friend came round after work with his diamond saw and deftly cut a slot through the concrete path avoiding cutting the re-bar that joins slabs. We were able to clear enough space below the bars to slide two lengths of  40 mm waste pipe to act as conduits for the SWA cable that will power the pump, and a 25 mm MDPE water pipe that will branch off the pump output and feed the horticultural areas.

Next he cut another slot in the rim of the borehole to be one brick course above the overflow. This again will take two lengths of 40 mm waste pipe, one for the pump suction pipe, and the other for the return water from the heat exchanger that will be tucked down the overflow.

Bless him he is returning on Monday evening to make a start on the pump house, that will be based on a 900 x 600 mm flag stone and about 12 courses of bricks high.

[awemawson]

Another bits and pieces day. I wanted to finalise my plumbing order from BES because I have decided to go with 68 mm down pipe tube as the conduit from the new slot in the well to the 'pump house' to take the actual suction hose - the 40 mm was a bit tight for the hose. Now I had a suitable bit of 68 mm down pipe but no 90 degree bend (well actually 91.5 degrees in rain goods!) to take it from below ground into the pump location hence having to order and I might as well sweep up the rest of the bits needed.

Trying to concentrate on what was already to hand and allocated and what was on shortage proved impossible with a flock of geese honking and people milling about shearing sheep so I used the expedient of threading allocated bits of plumbing on baler twine and tying them where they will be used - I think I got there in the end but interruptions like 'the power is off' when in fact a shearer had plugged into but not switched on a socket tried my patience that was getting shorter by the minute !

OK order placed - next job check that I have enough SWA cable and appropriate glands and pick a source and a route - done (tick)

Next check where I will be able to cut the feed to the horticultural taps and connect them to well water. This involved a bit of digging and to my horror I discovered an underground Tee joint and branch that I had no recollection of (but I must have installed it!). A lot of faffing about, turns out one pair of taps must have been connected before the rest, and before these concrete slabs were poured, but the routing of the new feed and isolation of the old shouldn't be an issue. Done (Tick!)

Next - sort the overflow fitting on the chiller tank. This is solvent weld and of a size not easily available, so I cut the old tank connector, mounted it up in the lathe and bored out the stub of old pipe so that I can re-use the fitting with a salvaged length of the old pipe. Done (Tick!)

Next - dry fit the connection from the chiller tank outlet to the Grundfos pump so that the location of the tank is set. Done. (Tick!)

Next - make four 'tank location brackets' - drill and tap chiller frame base and fit brackets  refit tank - done (Tick!)

[awemawson]

First job this morning was to bump out 120 bricks and two 900x600 flag stones ready for when my friend arrives on Monday evening to make start a start on the 'pump house' masonry.

Then taking my life in my hands I decided to have a crack at soldering the big 54 mm connections that I've been so concerned about. At the time of soldering it needs a flow and return 28 mm pipe already in the reducer so that they could be all done in one 'heat'. A bit of a mock up first to make sure that the 28 mm pipes were the correct length, and a bit of adjustment in the lathe with emery cloth as they were a bit too tight for comfort in the 54 mm to 28 mm reducers. I suspect that this is actually Imperial 1" pipe not 28 mm - I've had it a long time !

So all cleaned up, heat exchanger on the welding bench solder and flux to hand, my big butane torch set up and my small propane torch to hand (my concern was getting enough heat into the beast) and off we go. All joints fluxed up, both torches on the first joint and we are getting there Solder started to flow nicely - a wipe again with the flux brush and a tad more solder and the joints seem good. Rinse and repeat on the second side, let it cool, take it outside for a good forward and reverse flush out to hopefully get rid of the zinc chloride flux, a blow out with the air line, and refit it to check that I got the pipes in the right holes and of the right length - phew yes 

As you may imagine completing the soldering on these big 54 mm joins is a big weight of my mind - the rest is more normal sized plumbing.

Time for a coffee   

[awemawson]

After this mornings excitement I had an easy afternoon, just cutting a top cover / lid thing for the chiller frame to keep the muck out if it has to go back into the foundry before the roof is fixed. Just a 750 mm square of 1.2 mm Zintec sheet with twelve holes in, and appropriate holes drilled and tapped into the top of the frame.

I actually cheated, and used the drawing for the 'bottom shelf' but deleted the notches for the uprights as they are not needed as it sits on top. I must have made a slight error in the original drawing, as to my surprise the hole pattern isn't symmetrical. I've suitably stamped the frame and panel so I can get them back together after painting, and must remember to do the same to the 'bottom shelf' before it is removed for painting.

Out of curiosity I'm now off to look at the Autocad drawing - not that the error matters one jot !

[awemawson]

With the latest plumbing order not expected until Tuesday / Wednesday it's time to turn my attention to the electrical requirements of the cabinet. Faily simple really:

16 amp / 3 phase input socket
3 phase on / off switch
Motor starter / over current unit for pump (salvage from original chiller)
12 volt DC supply for temperature indicators (already have one)
A few DIN rail bits and terminals (got)
A box to put it all in

Now the box - could I use the one from the original chiller? It's really too big, and rather rusty. Too big doesn't matter, and the rust is no major problem so long as the paint on it will 'feather edge' as I don't want to have to strip all the paint off.

So I started stripping out all the electrical gubbins from the original cabinet, and when I had a bare box did an experimental de-rusting with a sanding disk, wire wheel and stripping disk. I decided that it actually was feasible, so giving it a good clean up I've given it a coat of hammer finish blue.

Some of you might think that the paint scheme is remarkably similar to that I used on the 110 KVA generator - there's a good reason for that 

I've not sprayed the door as I need to make holes in it for the temperature indicators and also a door interlock switch that I have ordered that will double up as an on / off switch

[awemawson]

This morning I cut the front panel with an aperture that will take the electrical box, and two brackets to support it in the same way it was supported in the original chiller.

I'd intended to just spot weld the brackets to the front panel - both are 2 mm zintec sheet, and as soon as they flexed the welds were giving way, so I replaced the welds with an over abundance of screws !

Jury rigging a temporary support I was able to do a test fit of the box in the hole - now I can mark the brackets for the final mounting screws that go in the sides of the box.

[awemawson]

So my friend came round after work and we dug the footings and filled them with concrete. The idea is to come up in brickwork a couple of courses, lay lintels across the pipe runs, come up a few more courses in brickwork then lay the lower slab. Then onto this build up in brickwork to a suitable height to easily house the pump and leave working space before putting a second slab on as a roof.

[awemawson]

So I started the day reorganising the well pump fittings to raise the controller sufficiently that the priming plug is more accessible, and getting the suction and flow fittings in the correct orientation. This is so that the slab can be marked out for core drilling.

Then knowing that the manhole frame can soon be concreted back I made a pair of lifting handles to more easily re-fit the cover.

This done my friend returned and set the first few courses of brickwork. Two below ground to take the lintels, and the two above onto which the first slab will be set - hopefully tomorrow.

[awemawson]

I've been working out pipe runs inside the new chiller unit today, having decided to run everything in 28 mm copper rather than the 32 mm MDPE as it is a bit more stable.

Amusingly my rolls of 32 mm DIAMETER  MDPE pipe say 32 mm RADIUS  printed on the side! - I can assure you that it isn't  Someone in China is perhaps confused 

My friend made good progress this afternoon with the brickwork. First cutting a suitable hole in the the lower slab for the pipes to pierce, and also a 'drip line' on the underside. Then building up the brickwork to 3 courses from finish height. Three more courses, a roof and a door and it's finished

I had to do a test fit of the pump naturally !

[hermetic]

are you going to drop a piece of plastic drainpipe over the wires and pipes between the slab and the ground to stop the critters chawing on them?

[awemawson]

The 'suck' pipe will be enclosed in 68 mm down pipe all the way from the well to the pump compartment, The output, which will be 32 mm MDPE will be in a short length of similar pipe just for the vertical bit. The SWA cable probably will be ok but now you mention it I may sleeve it with 40 mm waste pipe.

In the wife's chicken shed I had to run the 25 mm MDPE water pipe through a bit of scaffold tube as the rats ate it 

[awemawson]

Last night I drew up a substantial 28 mm pipe mounting clamp and set it 3D printing a pair on the Cetus in ABS. 8 hours and 14 minute job so left over night churning away.

I need substantial clamps for where the four pipes leave / enter the chiller unit and have hoses dangling on them - no easily available plumbing type clips are heavy enough duty.

This morning the first pair were printed and came out OK  apart from a bit of de-lamination of layers near the through holes - (for an idea of scale the through holes are 10 mm). I have introduced some acetone into the cracks and clamped them up hoping that it will re-bond, meanwhile the next pair are printing which should finish about 4:30 this afternoon - only two more sets after that !

[djc]

I need substantial clamps for where the four pipes leave / enter the chiller unit and have hoses dangling on them - no easily available plumbing type clips are heavy enough duty.

What you have drawn looks remarkably similar to the clamps used for hydraulic hoses on excavators, hiabs and cherry pickers.

[awemawson]

Yes that's what I based it on - I have some for smaller hydraulic pipes on my JCB but not that size.

[awemawson]

So I managed to print a second pair of pipe clamps in ABS - these ones have to be raised 60 mm on stand-offs to clear the first pipe, but the trial fit went well. Again a bit of delamination glued with acetone but should be OK.

I have a third pair printing at the moment - these are in PET-G as I'm running low on ABS. But this time I've rotated the model so that it is lying on it's back, so if there is delamination the holding screws will hold it together - I should have done it this way first time !

This pair won't be done until about 11:30 tonight so unlikely that I can set another overnight run - you never know - there may be a good film on !

[awemawson]

So of course I HAD to do it - I stayed up until silly O'Clock waiting for one set of clamps to finish so that I could start another set to run over night.

So (I think) that's the last of the 28 mm pipe clamps made. I'd forgotten how nicely PET-G prints, but it's a b***r to get  off the build plate !

I now need to make a little jig to drill holes to mount them, as these mount on the underside of the cross rail, and are in a place compromised by vari-focal glasses 

[awemawson]

For a jig I need about six inches of suitable angle iron - casting about I found a grotty rusty bit no use for anything else, so a bit was loped off the end and sand blasted to get the majority of the horror off it, and I laid out the two holes for the pipe clamps at 48 mm centres to coincide with the centre line of the heavy box profile that I made the frame from.

This allowed me quickly to drill and tap the four M8 holes for the last two  pipe clamps while standing on my head under the horizontal frame bar.

Once the clamps were fixed, I could finalise the pipe layout, but first I had to solvent weld the Grundfos pump feed from the tank, so that the position of it's output pipe was fixed. While the solvent weld glue was setting up I re-worked the fixings for the brackets that hold the electrical cabinet in place. I made up 1" wide strips with four studs tapped and soldered to co-respond with four of the holes (that were previously legion!) giving a much neater appearance

OK solvent weld now handle able, so I could fit the pump and know where it's vertical output will be, letting me finish that run of plumbing.

Nearly ready for dismantling and painting 

[awemawson]

A bit more work this evening and the 'Pump House is up to roof level - or is is really a barbeque 

Then the frame for the manhole cover went back having mortared in the two pipes.

It'll be ready for electrics as soon as the brickwork ca stand an SDS drill !

[hermetic]

Looking good! Stellar job on the cooling unit!
Phil

[awemawson]

The time was right today to break down the new chiller unit and give all it's bits a coat of paint. I've tried to keep 'sets' of plumbing still pushed together (although not yet soldered) to aid re-assembly.

Once it was all apart and wiped down with Xylene, I lifted the frame up high on the forklift, put some kitchen foil on the castors to mask them, and gave the underside of the frame a blow over with the Silver hammer finish paint. While that was drying I gave the reverse side of all the panels and odds and sods a coat.

Then I was able to lower the frame and push it indoors to paint the rest of it's box sections.

By the time I'd done that, the panels and odds and sods were dry enough to invert, and paint their face sides.

All together it's not come out too badly - just short of 2 litres sprayed on ! After a major clear up and a shower I can now contemplate putting it back together tomorrow.

[awemawson]

Looking good! Stellar job on the cooling unit!
Phil

Thanks for the kind words Phil 

[tom osselton]

nice work!
 And just out of curiosity how did that turpentine bees wax anti rust mixture turn out on the long run?

[awemawson]

Thanks Tom

The turps / beeswax concoction works very well on the wood working machines - a nice thin lubricant / anti-rust coat that doesn't compromise the wood surface. It does however have a tendency to solidify in my plastic hand spray bottle - I suspect that the solvents migrate out - just needs a drop more turps every now and again !

[howsitwork?]

hmm n8ce idea Andrew

had forgotten that one. Good to see isolation has kept you busy !

Ian