Resurrection of a CFEI 100 KVA Induction Furnace

[awemawson]

A series of little catch up jobs this morning as rain is threatened over the next few days:

Firstly I fitted pipe clips to the outside of the foundry and fixed the flow and return cooling pipes in place.

Then I bored a hole in the wall for the new Chiller tank overflow and fitted a suitable right angle of 40 mm waste pipe - still short of a pipe clip - giving an up stand for the overflow to go into.

Then I back filled the main pipe trench - again a few inches of earth followed by a warning tape followed by the rest of the back fill. The tape warns of cables below but I expect it'll stop rampant digger drivers in the future despite it being water below 

Then the man hole frame and cover got a good greasing before being put in place after what seems ages  of a temporary cover.

[mattinker]

I am really looking forward to seeing this installation!

Cheers, Matthew

[awemawson]

And so you shall Matthew - I presume that viruses permitting you will be over in December?

After lunch the small oak door for the pump house got it's first offering up and planing to the wedge shape it needs to be (1/4" discrepancy in width top to bottom in the opening!) But then the heavens opened up and stopped outside work.

Quite a deluge, and (SO FAR!) the roof sealing seems (seams!!) to be working in the main span of the roof where the joints were leaking. There is still a leak where the two buildings join and I think perhaps a fillet of cement followed by the sealant is gong to be about the only way to seal it.

To be honest I'm not entirely surprised, but now I have it on video I can work out exactly where it's coming in (and conveniently dripping on the old electrics  )

[mattinker]

And so you shall Matthew - I presume that viruses permitting you will be over in December?

Viruses permitting!

[awemawson]

Still raining here so no more roof investigations or door fitting. But I thought at least I can stop up the 'blemishes' in the pump house door with "Brumers Stopping"  ready for varnishing, if only I can find my little tin . . .well I couldn't 

Buy on line ? - silly money and long delivery - ruled that one out.

OK you've got waterproof wood glue and lots of fine oak sanding dust having faired the door planks - make some stopping ! I have to say that 'Andrews Stopping' came out much the same consistency as the real thing, and the colour certainly will be  better match as it's the same wood!

No doubt it will shrink so I left it proud for later sanding down - probably tomorrow.

[awemawson]

Rain threatening again today, so I shot out first thing and measured up and planed the Pump House Door to final size, and made a pair of toggles to retain it. Then I sanded it down and gave it it's first coat of varnish along with the toggles.

Then I pumped out the water from the chiller tank, and removed all the temporary testing loops of flexible pipe, and trundled it into the foundry to it's final location.

The 10 metre coil of 25 mm bore reinforced PVC hose and Jubilee clips arrived yesterday, so I was able to connect up the umbilicals from the wall to the unit for the flow and returns from the bore hole leaving I hope enough slack to pull the unit forward for servicing.

Then it was time to fill the tank with glycol solution. I have two drums of diluted glycol - one diluted to -3 degree Centigrade protection, and the other to -30 degrees centigrade. I moved the pallet with the drums into the foundry and pumped directly into the tank, first half filling with the -3 solution, then topping up with the -30 solution, which according to my Brix meter gives protection to -8.5 degrees C. This will all change when the furnace and driver unit are attached as they contain quite a volume of coolant.

Moving the Furnace Driver into place, although the rubber pipes that connect it to the chiller are just long enough I've decided to replace them. they are rather soft and these were the ones that the rats chewed the end off. I've ordered another 10 metre coil of 25 mm bore PVC reinforced hose - I hope that it's happy carrying glycol solution.

[awemawson]

So time to sort out the new home for the generator after all these months.

The stable, where it is next going, was stacked with crates of fire wood, IBCs, Pig Weighing Crates, Wheelie Bins and all the paraphernalia that accumulates and it all had to come out. Some could stand a bit of rain and were put in the inner farm yard, but all the wood was transferred to the tractor shed having moved the generator into the yard and covered it in tarpaulins for the night.

I have four very heavy duty wheels and tyres (rated 1700 kg each at 15 kph) whose hub bearings have completely rusted solid. Knocking the races out has left a bore a bit bigger than a scaffold pole, so the plan is to jack the generator up, slide poles through holes in the RSJs that form its base, and put the wheels on and roll it into place. This is needed as I can't approach the final resting place with the fork lift at the right angle so it needs manhandling the length of the stable over very rough concrete.

Meanwhile the fork lift has a new temporary garage !

[Sea.dog]

I feel a woodshed build approaching 

[awemawson]

Already got one Graham, up by the house, and it's empty, but there is a dead tree close to it that needs felling, logging, splitting and stacking so that it is deepest in / last to be used, before some of those Apple bins  of logs get tractored down to the house and stacked in it.

. . . any volunteers ?

[Sea.dog]

More than happy to destroy a tree. I need to do a bit of manual labour.

[awemawson]

First job of the day, put another and hopefully final coat of varnish on the pump house door and door frame. This should now be finished bar a handle to pull it open, and the making of a couple of plastic foot like spacers to stop it sitting on the (potentially wet) lower slab and rotting.

Then the big  move - pulled the tarpaulin off the generator, moved it so that it was roughly aligned with where it need moving, put an axle and two wheels on the front, and sat the back on a pallet. The theory being that I could push it with the fork lift to pretty well where it was meant to be.

Well theory and practice often differ  As the floor of the stable slopes I couldn't stop the front end gradually running off course and going down hill. An 8 ton block and tackle attached to a front chassis member  at one end, and a support RSJ of the stable at the other turned it's head in the right direction. Then the application of a pallet jack to the front allowed a friend to steer it while I pushed with the forklift.

Eventually we got it deep enough in to the stable and close enough to the wall that I was just able to get the forklift under the generator at 90 degrees to the side, pick it up and finesse it's positioning. Getting the fork lift back out was fun as it's a relatively narrow space reduced by the width of the generator, the length of the forks and of course the length of the forklift itself. I think it took about six back and forth jiggles with clearances measured in fractions of inches 

Generator placed and a start performed - it still works  Then started a considerable amount of putting away all that had been displaced. I gained some space by double stacking some pallets in the tractor shed but the stable isn't tall enough for that trick!

Main generator cable unrolled between the big blue Induction Furnace Driver and the generator, and yes, it's long enough so that's another unknown ticked off.

Now I need to sort out the generator exhaust to the outside world - it very quickly fogs up the stable despite 'Yorkshire Boarding' (6 inch planks spaced one inch apart) and fully open drive through doors either end.!

. . . but we ARE getting there 

[Spurry]

Looking good.
Not sure how your forks are secured on the Hyster, but when I have found myself in a 'sticky' situation, I just slide the forks off their backplate,
move the machine, drag the forks out from whence they are stuck, then pop them back on again. Can save a lot of 'tooing and froing'.
Not sure if that is possible with your machine. HTH.
Pete

[awemawson]

No Pete, my frame is pegged to stop the forks sliding off. I'm sure with a bit of work that it's possible - but not that easy (by design)

[Spurry]

No Pete, my frame is pegged to stop the forks sliding off. I'm sure with a bit of work that it's possible - but not that easy (by design)

Mine wasn't easy until I took the safety bolts out. Having said that, it's usually easier to just drop the complete backplate/fork assembly off the machine with a couple of small levers.
As your machine is a specific forklift, I did not think the latter facility would be available to you, but that the former might.
Pete

[awemawson]

So varnish dry, PTFE spacers fitted and door finally in place. Why PTFE - 'cos I happened to have a stick of the right diameter sitting by the lathe !

With the door on it was now worth making and fitting the anti-vermin shield round the cable and pipe entries in the Pumphouse floor. I drew it up in Autocad and had intended to cut a trial in plastic using the Laser Cutter, but when I turned it on, on performing it's initialisation homing sequence it's ignoring one of the sensors and crashing into the end stop. They are hall effect sensors and in fact waving a bit of metal at the 'faulty' one it lit up so possibly a broken wire - something to investigate 

So never mind - cut it in metal. Actually it fitted rather nicely - three bits needed to be able to get it in place, and rare earth magnets join them pretty effectively.

But having cut the steel on the CNC Plasma Table why is the welding shop full of fumes? The automatic fan hadn't turned on as it should but works happily if manually turned on. Something else to investigate.

OK next job, extend the generator exhaust to a height that it will clear the feed bin lids when they are open, and make up the length to take it outdoors. It's 2 1/2" BSP heavy walled steam pipe. I had about 50" of it and a length of flexible exhaust left over from when I got the generator. Careful measurement told me that by lopping 14" of the pipe and threading both ends I could get the height right and there would still be enough to reach outside if I used a bit of the flexy that already had a threaded stub welded in one end.

So how to thread 2 1/2" BSP - my threading gear stops at 2". No alternative really than single point threading it on the lathe using a fixed steady.

Slight snag - no 55 degree external threading tips - got internals but that's no use. Hang it it's not a nuclear submarine it's an exhaust - use a 60 degree tip and wing it 

Slight adjustment to threading depth to get a reasonable fit, and a bit of crest rounding with a file and my 'thread gauge' (a malleable iron elbow) was a tolerable fit. Time to assemble it all.

Firstly I bored a five inch hole through a six inch Yorkshire Board in the stable wall which should be enough clearance to keep the hot exhaust off the timber. I need to find some insulating material to support where the pipe passes through the timber.

Then all was screwed together and a test run performed - all OK

Incidentally I went to fire the generator up last night and there was a very loud bang and a spurt of flame from the side of the generator. Scary at the time, but it proved to be the cheap Chinese battery isolator switch had failed in a spectacular way spewing it's contacts in molten form across the top of the battery. Needless to say I took the switch out of circuit!

[awemawson]

WE HAVE A WORKING INDUCTION FURNACE !

What a day 

I started by making a bracket to hold the generator exhaust pipe central in the hole in the Yorkshire Boarding to try and avoid fires.

Then, as the new roll of 1" PVC reinforced pipe had been delivered yesterday set to reworking the hoses that run from the new chiller to the furnace driver box. All fairly straight forward, jubilee clips onto hose barbs, though I have double clipped all ends just in case.

At this point I was able to connect the chiller to the furnace driver which was already connected to the furnace body (where the crucible is) and test for leaks.

All was well except for a slight drip from one of the 1-1/2" unions that the driver unit uses. This was eventually cured once I'd found an ancient tin of Boss White that was still workable, the first one being solid !

So now dare I try powering up?

Cables run out - by heck they are HEAVY! Generator started, furnace driver switched on and it immediately tripped it's main breaker - not good, but knowing that it had been OK on genuine mains 3 phase at low power it pointed to a generator or cable fault.

Measuring the input to the Furnace driver voltages were all over the place - 250 (ish) between two phases 415 or so between others. At the generator end all was well with the correct 415 between phases.

It MUST be the cables, but I'd buzzed them through for continuity when I dug them out recently and they were OK. Very odd 

Major engineering feat opening up cable ends (plugs / sockets) and to my absolute HORROR found Live 1 and Earth interchanged on one of the sockets. I'd hunted for the core to test with a meter probe but not paid attention to what connected to what. Now I know for certain that this cable (these cables) had been working fine before I moved from Bromley, so how the heck had two wires changed place in the mean time.

Then it dawned on me. Shortly after we arrived here EDF wanted to recable their overhead wires into 'bunched cables' and I'd had my previous Agrekko  generator running for a couple of days while they were on site. A week later they'd rung me up and begged the loan of the generator as it was towable, to keep a local village powered up as a care home couldn't be without power. I remember saying that I had the heavy cables but no socket for the other end for them to use, and getting the reply 'No problem we'll remove the cable end and put it back afterwards.

99% certain that the EDF contractor had interchanged those two wires - hideously dangerous 

OK now we have proper 415 volt three phase 

Does the furnace driver work - no  I got the same error that I had had a few weeks back that the water flow wasn't being detected. OK link the error out and press on. Unit goes 'Pret' (ready) and pings the furnace body determining it's resonant frequency.

A length of 1/2" steel black bar in the crucible and try proper heat. Now I daren't actually melt anything yet as I have no compressed air to invert the furnace and dump the melt out, so lowish power test.

Good signs - smoke off the residual oils on the bar as it heated then a nice dull red glow - I wound the power up to 20 kW just to get it a bit brighter and decided that it was probably as well to quit while I was ahead.

The temperatures on the water chiller all looked sensible but in my excitement I failed to take pictures.

. . . in all a good day and a big relief  - now for . . 

[pycoed]

Bravo - but, but, but,what are we to look forward to next? How about major hydraulic repair on the tractor or JCB? (Just finished minor hydraulic repair on mine)

[PekkaNF]

14 pages thread and on #340 post it is alive! Anotoher great mega project. Even writeup is major work, not to mention the several units fixed, checked, moved overhauled during the process. I am very impressed. Showed the picture of the generator to my wife and said that we need one. She said "sure" and then I told what size it is....she was ready to dial for a professional help.

[Sea.dog]

Fantastic news Andrew. Well done, again      

[tom osselton]

Glad to see it working! ....... So what are you going to cast?

[mattinker]

Well done mate! Soon be time to break out the moulding sand and the flasks! I don't remember whether you were using green sand or petrobond?

Cheers, Matthew

[Pete.]

Good show!

Just make sure you keep your ring finger out of there when it's switched on   

[awemawson]

Thanks for the comments chaps

It's a huge relief to find that the Furnace Driver is fundamentally working still after all these years lying dormant. After all the excitement yesterday I readily admit that today I feel exhausted, so trying to scale back on activity just wanted to do a bit of 'first fix' for the compressed air supply, ready for the bits that should arrive tomorrow.

First I had to weld two more vertical box sections to give  something to fix the panel to, and I decided to mount a twin 13 amp socket as well as the air termination. (The location is well down towards the large roller shutter and a socket will be handy for work outside)

In the end I did do the wiring for the socket - this will eventually be part of a ring main, but currently is wired as a spur as the next socket round the ring main will be where that roof leak still hasn't been cured so cannot be completed.

. . . time to put my feet up 

[awemawson]

Rather late in the day my plumbing bits arrived, so compressed air has now reached the foundry 

Or rather it hasn't yet as I'll leave the pipe thread sealant on the stainless and brass screwed fitting overnight to go off properly before opening the isolator valve.

. . . getting there . .

I'm now beginning to look at the cosmetics of the CFEI furnace driver where it has suffered significant surface rust over the years but I think it is recoverable if not left too long. Can't be a proper 'strip and blast' job as too much to dismantle - some panels and doors can be removed, and the rest will have to be a careful masking job.

[awemawson]

Now that I have compressed air plumbed to the foundry I am able to work on the two 'furnace bodies' that I have (an "inverter" and a "tilter" )

Today it was the turn of the "Raydyne Tilter" - I had re-built this body years ago (2006) replacing the crucible with one from a batch that I had had made behind the old Iron Curtain (as they weren't available as stock items). I also modified the control system from purely pneumatic to 'air over oil' at the suggestion of the late John Stevenson as just using air it was difficult to control 'bounce' as it went up and down. I built in a differential 'up' and down' system using one way valves and a flow rate control for each direction.

The oil reservoir is a cut down carbon dioxide cylinder and most of the plumbing was domestic water fittings as that was all I had access to.

A quick inspection showed that a 15 mm stainless pipe had been whacked and kinked but probably still worked and a few brass pipe clips had sheered off. So I connected it up to the new compressed air system and tried the 'up /down' lever - it was bent but judicious bending got it moving however apart from a bit of hissing nothing happened 

Checking the reservoir - yes there was oil. Slackening off fittings - yes oil from the 'up' outlet but nothing at the cylinder 

As I turned away there was a big 'POP', and turning back oil was spewing out towards the Oxy-Acetylene store at a great rate of knots - the flexible hose to the cylinder has burst off it's crimp. Over the years the hose has adversely reacted to the hydraulic oil and was blocked - after all it was only designed for water!

A quick assessment gave me a count of six flexible hoses - replace one replace ALL I think, and I was about to order them up when it struck me - I now have proper hydraulic pipe and fittings with the crimper to go with it - make your own. So I will !

I'll do a bit of re-design to eliminate as much as possible of the water plumbing and do it all in 1/4" BSP hose and fittings as it's rather more flexible than 1/2" (although I have stocks of both)

(Pictures below are of the crucible and a test firing I did shortly after replacing the crucible (to dry the lining) back in 2006, NOT today but the other pictures ARE today)