Axeman-Anderson Anthratube 260m disection

I started the disassembly of my well-used AA boiler. I was able to get all five bolts loose that hold the boiler to the base. Using one fork on my loader I was able to lift the boiler off and set it aside.

Below are some photos of the separated pieces.

The grate is like a drawer on rollers. The rollers are siezed and one [at least] has a worn flat spot on it. The drawer was jammed and the linkage for moving the drawer back and forth is really worn.

The bottom of the drawer is stepped to scrape off the lowest layer of ash from the coal fire sitting on the drawer bottom and extending up into the firechamber. The grate had alot of accumulated ash stuck in the corners from the limited movement of the grate.

Below are photos of the grate, or ash drawer. It is stuck on it's rollers and the linkage for moving it back and forth is badly worn. The original full stroke or 'shake' of the Grate/AshDrawer is 2", the combined wear reduced this to 1", so the grate was hardly moving.

The tube sticking out from the side over the drawer is an ash temperature sensor. According to the AA wiring diagram [thanks Ian ! ] this sensor will fire up the motor and make the grate move and get the fire hotter, just to prevent the fire from going out during warm weather. CORRECTION: the ash sensor controls a solenoid that disablees the grate-moving mechanism until the ash cools below 140*. This prevents shaking hot, still burning coal into the ash pan.

Does it use a standard cam roll style bearing on the grate?

Figuring out the fire pathway is a bit confusing from the poor diagram on the Axeman-Anderson website. So I'm going to show a few photos of various parts of the boiler.

The first is the bottom of the firechamber, and the base of the boiler. The cone-shaped 'funnel' in the corner directs the trapped fly-ash from the flue into the ash pan.

In the top of the firechamber where the tine of my forklift protrudes is the passageway where the flame and heat start down the center of the double-tube heat exchanger. A high speed fan pulls the flame/heat off the top of the coal and pulls it down the center tube where the forklift tine is.

The other tube dropping into the firechamber at an angle is the coal feed tube. This is the tube at the tip of the forklift tine. The auger keeps this tube full of coal, so the firechamber is full from the sides tapering up to the feed tube.

There is another tube opposite the forklift tine. This is an inspection tube, it is also where the operator adds wood and firestarters or kindling/paper to start a fire. There is a flat plate that covers this port on the outside of the boiler.

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Nice photos. Very similar to the AHS coalgun. Let me make a suggestion to make it easier to follow the story line. Post the images in line with the narrative description. Like I did when I told the boiler removal story. Here's how to do it.........


[Removed old no longer valid information for images]

The flames and heat come down this pipe, it is about 6" in diameter. At the end of the tube you can see the coal feed tube coming into the top of the firechamber at an angle.

The flame and heat are pulled down the center tube, the turned 180* and forced down the outer perimeter tube in the second photo.



At the end of the perimeter tube at the top you can see the start of a passageway that forces the air to enter on the left, swirling to the right through a screw-shaped passageway. This 'swirling' and turbulence is what AA and AHS claim create high heat transfer through the water jacket.



The flames, hot air and fly ash are swirled through the perimeter tube forced through the curved passageway, then into the flue pipe. The air and ash enter the flue pipe from the side, at an angle, and the air and ash again swirl around inside the pipe, the ash is separated by centrifugal force and collects in the funnel in the bottom. The funnel dumps the ash onto the edge of the grate just above the ash pan.

Yanche wrote: Then view your uploaded images. Next copy and paste the URL of the image to where it needs to be. For example your first posted image is URL, ...

Just a quick note. This is actually quite easy to do in the new forum, once you upload on the posting page there's link that automatically will place the the image inline in the post.

The boiler has had two repairs that I've found so far. The repaired lip at the bottom of the firechamber.



The lip around the fan mounting flange had a piece welded in to repair the corrosion from the domestic water coil leak that corroded that end of the boiler. The boiler surface is badly corroded and the hot water coil is now using a 1/4" thick rubber gasket to seal the water leaks.



The steel lip is not wide or high enough, I will build this up with weld or weld on a piece of steel. The lip seals against a piece of fiberglass rope.

GL

LsFarm wrote:The tube sticking out from the side over the drawer is an ash temperature sensor. According to the AA wiring diagram [thanks Ian ! ] this sensor will fire up the motor and make the grate move and get the fire hotter, just to prevent the fire from going out during warm weather.

I also have the AA literature and my understanding of the operation is slightly different.

I understand that the sensor is wired so that when the fan is operating the grate will only operate if the ash temperature is low--to prevent dumping still burning coals.

AA has a separate interval timer that operates the blower whether of not the aqua stat is demanding heat and this is the circuit that prevents the fire from going out during warm weather.

You're right Bob, I must have been reading the literature upside down.

There is a solenoid that the ash temp sensor controls that will keep the grate from moving untill the temp sensor reading drops below a factory setting of 140*.

Like you said , to prevent shaking out still-burning coals.

That solenoid and the other controls are in a pile in an ashpan, I need to get them sorted out.....

The AHS boilers have a separate motor and controls running the grate movement. One of the 'modern improvements' made on the AHS over the AA.

Greg L

LsFarm wrote:You're right Bob, I must have been reading the literature upside down.

There is a solenoid that the ash temp sensor controls that will keep the grate from moving untill the temp sensor reading drops below a factory setting of 140*.

Like you said , to prevent shaking out still-burning coals.

That solenoid and the other controls are in a pile in an ashpan, I need to get them sorted out.....

The AHS boilers have a separate motor and controls running the grate movement. One of the 'modern improvements' made on the AHS over the AA.

Greg L

I was told (by AHS) that the ash temperature sensor used on the AA boiler was a reliability/maintenance problem with the result that AHS first went to an interval timer that was only powered when the blower was running to control the grate and then began to offer a Fuji controller with thermocouple as an option. This option has only been on the market for a couple of years but AHS reported the initial reliability was good. Yanche is looking to retrofit the Fuji controller to his AHS boiler and I would think it would be a simple retrofit to the AA boiler if you run into reliability issues with the sensor used on the AA boiler.

LsFarm wrote:The AHS boilers have a separate motor and controls running the grate movement. One of the 'modern improvements' made on the AHS over the AA. Greg L

Something tells me this A-A may be right out of Star Wars in a little while.

Bob wrote:I was told (by AHS) that the ash temperature sensor used on the AA boiler was a reliability/maintenance problem with the result that AHS first went to an interval timer that was only powered when the blower was running to control the grate and then began to offer a Fuji controller with thermocouple as an option. This option has only been on the market for a couple of years but AHS reported the initial reliability was good. Yanche is looking to retrofit the Fuji controller to his AHS boiler and I would think it would be a simple retrofit to the AA boiler if you run into reliability issues with the sensor used on the AA boiler.

It is true, my timer controlled grate only runs when the combustion blower is running. I've never had burning coals dumped in the ash bucket. It's also true that I'm adding a thermocouple. I plan to at first just measure ash temperature and perhaps later use it for control. I'm satisfied with the timer control and look to the thermocouple control for preventing the fire from going out in summer months. Something the AHS boilers currently are not designed to do.

coaledsweat wrote:

LsFarm wrote:The AHS boilers have a separate motor and controls running the grate movement. One of the 'modern improvements' made on the AHS over the AA. Greg L

Something tells me this A-A may be right out of Star Wars in a little while.

To be correct about the improvement credits. Eshland (prior owner) was the company that improved the A-A design. The design improvement that can be credited to AHS is the thermocouple controller. A year or more of testing will tell if there will be any "Yanche" design improvements.

The Grate or AshDrawer does not come out the top of the boiler base like it does in the smaller unit. I had to unbolt a steel plate end of the base and drag the drawer out.



It's quite heavy, made of 1/4" and 1/2" plate steel, so I slid it out on the forks. The Grate/Drawer is in pretty good shape, and will be returned to service as is.