Author Topic: Coal Fired Vertical Boiler  (Read 19793 times)

Offline Chipmaster

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Re: Coal Fired Vertical Boiler
« Reply #15 on: October 25, 2015, 02:45:02 PM »
We were ready to close up the boiler and decided to solder the upper tube plate, the foundation ring and the fire hole into the outer shell in a single session using silver solder with a lower melting point. I threaded the ends of a couple of steel bars which would act as handles when screwed into the appropriate bushes so we could turn the red hot boiler over.

Because of the risk of previously soldered joints coming undone during reheating, wire was wrapped around all the bushes to stop them falling out and four small steel U shaped retaining pieces were made to be screwed to the fire door blind bushes so that they couldn't fall off inside the boiler.

The whole assembly was scrupulously cleaned flux painted in and around all of the joints both new and old and set up on Robs soldering table. I haven't weighed the boiler but heating that much copper was clearly going to be a challenge.

I have no pictures or videos of us doing any of the soldering unfortunately. Anyway it was quite a task getting the boiler up to a temperature sufficient for the silver solder to flash around the joints but we managed it with heating capacity to spare. We started with the boiler the right way up to solder the upper tube plate then turned it over to do the foundation ring and fire hole. At that stage of the project we were using a second 29kg bottle of propane and we looked and felt like we'd spent hours in a sauna.

Andy

Online Jo

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Re: Coal Fired Vertical Boiler
« Reply #16 on: October 25, 2015, 04:37:26 PM »
 8) Looks like you got a nice flow there Andy

Jo
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Offline Don1966

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Re: Coal Fired Vertical Boiler
« Reply #17 on: October 25, 2015, 05:08:01 PM »
I really enjoyed the progress of making the boiler Andy and thanks for sharing them. Looks like a labor of love. There is quiet a bit of setups and soldering being done here. I.......like..............  :praise2:


 :popcorn:

Don

Offline Chipmaster

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Re: Coal Fired Vertical Boiler
« Reply #18 on: October 25, 2015, 07:58:23 PM »
Glad to hear that Don.
Thanks
Andy

Offline Chipmaster

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Re: Coal Fired Vertical Boiler
« Reply #19 on: October 25, 2015, 08:23:48 PM »
Cleaning the boiler both inside and out required several immersions in citric acid and a blast with a high pressure hose to get to the stage where streams of black copper oxide flakes ceased to come out of the boiler!

You can see the result of the cleaning in the pictures below where I had the boiler set up for a hydraulic test at home. The boiler is designed for a working pressure of 80 pounds per square inch.

I made the necessary plugs to seal the boiler, fitted a check valve, a cheap pressure gauge, filled the boiler with water and pumped more water in using a Stuart Turner boiler feed pump. I increased the pressure in increments of about 10psi holding the pressure for a few minutes and watched for leaks and kept checking the sides of the boiler shell for distortion. There were no issues and the boiler held twice its working pressure (160 psi) for twenty minutes which is the normal requirement for the hydraulic test.

The boiler inspectors did the formal hydraulic test after the Black Country Live Steamers club meeting in May 2012. The boiler passed and I was very pleased.

Andy
« Last Edit: October 27, 2015, 12:13:54 PM by Chipmaster »

Offline Chipmaster

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Re: Coal Fired Vertical Boiler
« Reply #20 on: October 25, 2015, 08:35:08 PM »
Meanwhile Rob made up the firebox doors.

Using two inch square steel tube for the door frame I machined the required curvature by bolting the tube to my faceplate at the required distance or radius from the centre and proceeded with a boring bar.

Rob made all the rest of the door parts then soldered and riveted them together, the result was excellent.

Andy

Offline Dave Otto

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Re: Coal Fired Vertical Boiler
« Reply #21 on: October 25, 2015, 10:13:48 PM »
Very nice!

I have been enjoying this project.

Dave

Offline Chipmaster

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Re: Coal Fired Vertical Boiler
« Reply #22 on: October 26, 2015, 08:29:58 AM »
The manifold which would carry two safety valves and a pressure gauge was a casting according to the plans. As the casting was not available we fabricated the manifold using bronze bar, effective but perhaps not aesthetically pleasing as the casting would have been.

Andy

Offline Chipmaster

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Re: Coal Fired Vertical Boiler
« Reply #23 on: October 26, 2015, 10:05:32 AM »
Machining the cast iron top for the boiler was a straightforward operation. However, the diameter of the iron casting was only just enough to cover the six inch diameter outer shell of the boiler. I had hoped that the casting would be large enough to cover the top ends of wooden cleading when the time came.
The 1.1/2" diameter steel chimney is attached with a flange and six 6ba bolts.

Andy

Offline Chipmaster

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Re: Coal Fired Vertical Boiler
« Reply #24 on: October 26, 2015, 06:02:38 PM »
The fire bars were fabricated using stainless steel strip 12mm x 3mm thick with four 10mm diameter legs.

Andy



Offline Chipmaster

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Re: Coal Fired Vertical Boiler
« Reply #25 on: October 27, 2015, 07:56:37 AM »
Metal Spinning.
The boiler plans show a brass rim or bezel just below the cast iron top of the boiler. I thought that would be a neat finishing  touch to cover the ends of cleading particularly if the ends of the wood strips were uneven. Or the brass bezel would go well with brass cladding.

I had no practical experience of metal spinning, I read about it in LH Spareys book 'The Amateurs Lathe' Chapter 15 and looked at various websites with videos showing how it's done. As the bezel would be a one off I didn't want to spend much time or money making it so my initial approach was to look for a suitable brass bezel for a clock. There were plenty of horology suppliers offering brass bezels but I couldn't find exactly the right bezel for my boiler - both size and shape in on go.

I approached a couple of professional metal spinners but they need the appropriate former. To me it seemed that if I made a former then I may as well have a go at spinning as well....

The former was made from a Iroko worktop offcut 40mm thick using a router fitted with a trammel bar and finished off on my lathe, the pressure pad was a piece of chipboard. I made up a spinning rest to be mounted on the tool post then profiled and polished the ends of a couple of steel bars and wooden dowelling for my spinning tools.

I bought small selection of  brass sheet with varying thicknesses from John Keatley Metals in Birmingham, they also supply material to spinners and recommended what I should use.

The pictures tell the rest of the story except for the spinning tool that I found to be the most effective - the ball race on the end of my ELU Router profile copying attachment. Spinning wrecked the attachment which I'd had for over 30 years without using it so it didn't matter.
Andy

« Last Edit: October 28, 2015, 09:03:02 PM by Chipmaster »

Offline Steamer5

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Re: Coal Fired Vertical Boiler
« Reply #26 on: October 27, 2015, 08:37:09 AM »
Hi Andy,
 That came out nice! Nice to see the ones that didn't make it too. The boiler looks like it's going to give you years of fun!

Cheers Kerrin
Get excited and make something!

Offline Roger B

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Re: Coal Fired Vertical Boiler
« Reply #27 on: October 27, 2015, 08:42:20 AM »
Nicely done  :praise2:  :praise2:
Best regards

Roger

Offline Chipmaster

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Re: Coal Fired Vertical Boiler
« Reply #28 on: October 27, 2015, 12:06:21 PM »
To get the boiler ready for its steam test I calculated the size of the safety valves required and bought the plans for '5/32" bore mild pop safety valves' from Pollymodels. Making the safety valves was straightforward. The rest of the required fittings were commercially made. The water gauge was supplied by Dave Noble http://www.davenoble.co.uk/ and the pressure gauge from Miniature Pressure Gauge Ltd http://www.miniaturepressuregauge.com/.
I bought two stainless steel superheater spears but haven't fitted them yet. The engines I have run with this boiler so far ran well enough without superheated steam.
I haven't got pictures of the connection to the wet header or the blower at the moment, I'll add those later.
Two hand pumps were set up to fill the boiler and all was ready for firing it up. Safety valves were set by filling the boiler with water and pumping it up as if for a hydraulic test. The boiler was fired several times before the official steam test to ensure everything was satisfactory and on 11th May 2013 the boiler passed the test.

I don't have many decent pictures of the boiler in action I hope the few I have added below will suffice and I'll upload some video(s) of it to You Tube.
Andy

Offline Chipmaster

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Re: Coal Fired Vertical Boiler
« Reply #29 on: October 28, 2015, 07:36:13 AM »
Here's a link to a short YouTube video of the boiler driving a twin cylinder marine engine.

<a href="https://www.youtube.com/watch?v=N8i8IXzii2Q" target="_blank">http://www.youtube.com/watch?v=N8i8IXzii2Q</a>

Andy

 

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