Can Anyone Help Me to Identify This Very Old Boiler Please?

[Neil WyattModerator @neilwyatt]

Posted by FMES on 16/08/2019 06:11:23:

I don't think it was for steam, looks similar to the old Geyser hot water boilers – large tea urn??

Regards

I suspect you may be right. It might even have been filled by lifting off the safety valve. That could suggest it would be filled once, the water heated up and not refilled until the next time it was used.

Be interesting to see inside with the washout plate removed.

Neil

Edited By Neil Wyatt on 16/08/2019 14:01:40

[SillyOldDufferModerator @sillyoldduffer]

Here's why I suggest it's an Autoclave:

Might have been operated this way. Water is run in by the lower valve until it overflows through the top valve showing the boiler is full. Both valves are closed. ( I think these are filler valves because both are flared to take low-pressure tube.)

The 'mud-hole' is opened and the items to be treated are placed on a shelf inside. Once the mud-hole replaced the fire is lit. The spigot underneath the fire door may be a gas inlet, perhaps used to ignite a solid fuel with minimum fuss.

The weights are adjusted to set the required pressure. This accurately determines the steam temperature inside, perhaps up to 200°C at 40psi. When wrapped medical gear or bandages are to be sterilised some bugs can only be killed by prolonged exposure to heat, perhaps 12 hours at 120°C or an hour at 170°C.

There's no steam outlet other than the pressure relief valve. Autoclaves are meant to produce heat so the steam – mostly – should stay inside. Letting it blow off just wastes energy.

When enough time has passed, the fire is killed and the weights lifted off the pressure relief valve. The design makes this easy to do. Hot water can be drained from the lower tap and used for other purposes.

I suggest the boiler is a close relative of the domestic pressure cooker, but was built to operate at higher temperatures and pressures. Autoclaves are common in medicine, but are also much used in industry. Any job where a controlled temperature between 100 and 200°C is needed.

The rivets suggest it's pre-WW2. If it's an autoclave, sealing with a mud-hole rather than a hinged door hints it's early, but not as early as Papin's Digester of 1679.

Dave

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[JasonBModerator @jasonb]

Posted by SillyOldDuffer on 16/08/2019 15:32:43:

 

The 'mud-hole' is opened and the items to be treated are placed on a shelf inside. Once the mud-hole replaced the fire is lit. The spigot underneath the fire door may be a gas inlet, perhaps used to ignite a solid fuel with minimum fuss.

The mudhole is as I stated earlier the small access cover under the firebox door used to clear sediment, how you would get anything usefuul in there I don't know. It is also not a spigot.

If by mudhole you mean the larger manhole then that would very much depend on the gap between the top of the firebox and the top of the boiler. If the firebox is below the manhole then possible, if it is above then it is purely for cleaning the boiler.

The upper test cock is also above the level of the manhole so you could not fill to that then open the manhole unless you wanted wet feet

Hattie, are you able to measure the height inside the boiler so we can get an idea of the distance the inner top is to the outer top.

Typical man hole is the large one on the side of the boiler, mudholes are the small ones on the corners of teh firebox placed just above the foundation ring for clearing sediment

 

Edited By JasonB on 16/08/2019 15:53:27

Edited By JasonB on 16/08/2019 16:27:58

[SillyOldDufferModerator @sillyoldduffer]

Posted by JasonB on 16/08/2019 15:50:35:

Posted by SillyOldDuffer on 16/08/2019 15:32:43:

The 'mud-hole' is opened and the items to be treated are placed on a shelf inside. Once the mud-hole replaced the fire is lit. The spigot underneath the fire door may be a gas inlet, perhaps used to ignite a solid fuel with minimum fuss.

The mudhole is as I stated earlier the small access cover under the firebox door used to clear sediment, how you would get anything usefuul in there I don't know. It is also not a spigot.

If by mudhole you mean the larger manhole then that would very much depend on the gap between the top of the firebox and the top of the boiler. If the firebox is below the manhole then possible, if it is above then it is purely for cleaning the boiler.

The upper test cock is also above the level of the manhole so you could not fill to that then open the manhole unless you wanted wet feet

Hattie, are you able to measure the height inside the boiler so we can get an idea of the distance the inner top is to the outer top.

Typical man hole is the large one on the side of the boiler, mudholes are the small ones on the corners of teh firebox placed just above the foundation ring for clearing sediment

…

Good points Jason, I am not claiming to have proved it's an Autoclave. As you say much depends on the geometry.

By mud-hole, I meant the large entrance at the top and my naming of boiler parts is likely amiss. Normally they're for inspection and cleaning, as there's no steam outlet on Hattie's device, I suggest it's used as a door.

My information on boilers comes mainly from POULTNEY. E, C., Steam Locomotives, Caxton, 1951. He calls the hose inputs for flushing boilers 'wash-plugs' or 'mud-plugs'. They're physically similar to what I think may be a gas input. Hard to tell from the pictures. May be elsewhere in the book but Mr Poultney fails to mention what those clamped man-holes are called; during maintenance he jumps straight inside the boiler without bothering to remove them! (Still a good book though.)

Dave

[Clive Brown 1Participant @clivebrown1]

I thought that as well as for cleaning, man-holes in full-sized were sometimes required for construction reasons.

eg; the proverbial "apprentice" would be sent in to hold the nuts for the cylinder mounting bolts, as in Jason's boiler.

[Dave HalfordParticipant @davehalford22513]

If this was built to be used as an Autoclave and the manhole is where items were placed to be sterilised why would the door be secured by a nut requiring a spanner to be used instead of a large handwheel or spider? It just doesn't look designed to be opened on a weekly basis.

 

It shouldn't be to hard to work out the intended pressure range with the lever dimensions and weight of each ball. You can see notches along the bar to position them, though if the total thickness is only 1" the steel is quite thin so would 2 balls ever have been intended to be used?

Edited By Dave Halford on 17/08/2019 09:44:11

[JasonBModerator @jasonb]

Dave. I very much doubt that the item below the firehole is a gas inlet.

1. We already have a grate for coal

2. If you look closely at the last picture Hattie posted you can see the tell tale oval shaped hole of the mudhole and the slightly recessed mudlid behind it. we then have the cresent shaped bracket which is vertical so hard to see it's shape, nut and protruding stud.

3. If you look at the B&W section I posted further up the page you can see a similar arrangement with the large manhole at the top and several smaller mudholes including two just above the foundation ring, the third would have allowed access to the cross tube to clear any sediment from that, expect there is one for each cross tube out of sight.

Yes Clive the Manhole was also used during construction for access, things like inserting the carrot bolts that pass out through holes to secure a traction engine cylinder to the top of teh barrel.

Edited By JasonB on 17/08/2019 10:17:32

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