AHS S130 Coalgun- Puffbacks & Explosions

greenftechn wrote:

What exactly is AHS doing today to solve the widespread explosion problem..

We are dealing with these on a case by case basis. There are solutions in each case, but given that there are multiple factors, including coal source, and the individual user's management of the boiler, there is no blanket fix. Generally, draft, correct positioning of the fire, and avoiding too rapid introduction of fresh coal to the fire are the keys. Anyone using the Coal Gun is free to contact us for support for this or other issues.

You need a way to control ashing rate. It feeds too much coal when it runs.

You need a way to control ashing rate. It feeds too much coal when it runs.

There is an updated control for the grates that offers fine grained control of how much coal can be fed at any one time. This is referred to as a "Mode Switch". The manual will be updated after the first of the year to detail this. It is standard on all new Coal Guns.

greenftechn wrote:

You need a way to control ashing rate. It feeds too much coal when it runs.

There is an updated control for the grates that offers fine grained control of how much coal can be fed at any one time. This is referred to as a "Mode Switch". The manual will be updated after the first of the year to detail this. It is standard on all new Coal Guns.

Will you provide a bit more detail on this control function? Is this capable of retrofit on older units? What would the retrofit cost be? --materials? modifications required beyond new control?

I've attached the current excerpt from the manual. Older boilers can be retrofitted. Boilers from 2011, when the chain drive was replaced with a direct drive grate mechanism are especially good candidates for the retrofit, as these are more prone to being slug fed. I don't have a cost ready at hand.

greenftechn wrote: By: greenftechn On: Mon Nov 25, 2013 9:22 am
I've attached the current excerpt from the manual. Older boilers can be retrofitted. Boilers from 2011, when the chain drive was replaced with a direct drive grate mechanism are good candidates for the retrofit. I don't have a cost ready at hand.

I want to let everyone know that I have been working with Darren at AHS concerning the explosions and here is the update to my settings and their effect on the explosions. I have changed my hysterics to 1 from the 5 I had it set at. This causes the grate motor to run more frequently but at lesser intervals. Combined with the slowing down of the ash dump motor to 1/4 speed accomplished by my rheostat, there have been no explosions since Friday 11/22. I know that there needs to be much more time for the boiler to function in order to make any assumptions, but so far so good. From what has been written on this forum, there is not a one time fix for the problem of explosions and each case needs to be handled individually. Darren feels that I have made changes via rewiring the dump motor to run only with the fan and slowing the motor with the rheostat has accomplished what the retrofitted ash dump controller will do. I spent $25 for the rheostat and the motor rewiring was free. So we will have to see what the cost from AHS will be for the retrofit. I am not recommending that anyone make the changes to your boiler that I did without first consulting with AHS or another expert. I am just a frustrated coal boiler owner trying my best to make the boiler safe for my family and I am happy the AHS is finally helping me. I'll keep everyone posted.

Real NICE AHS. My compliments:)

My boiler was made in October of 2009, and has the chain driven grate mechanism. Would it be suitable for this modification, and would it be necessary for me to do so?

My boiler was made in October of 2009, and has the chain driven grate mechanism. Would it be suitable for this modification, and would it be necessary for me to do so?

I would not add the kit to a boiler that is working fine, with no puff backs. There is no likely harm in doing so.

What is different with the later models ashing operation vs. my chain drive version that would make them potentially more prone to puff-backs? It shouldn't matter much how the ash grate is being actuated (as in chain drive or direct drive), as long as its being turned on at the same temperature and by the same LC and thermocouple, and ditto being off at the same temperature, and its moving in and out at the same relative speed.

lsayre wrote:What is different with the later models ashing operation vs. my chain drive version that would make them potentially more prone to puff-backs? It shouldn't matter much how the ash grate is being actuated (as in chain drive or direct drive), as long as its being turned on at the same temperature and by the same LC and thermocouple, and ditto being off at the same temperature, and its moving in and out at the same relative speed.

rychw wrote:I want to let everyone know that I have been working with Darren at AHS concerning the explosions and here is the update to my settings and their effect on the explosions. I have changed my hysterics to 1 from the 5 I had it set at. This causes the grate motor to run more frequently but at lesser intervals. Combined with the slowing down of the ash dump motor to 1/4 speed accomplished by my rheostat, there have been no explosions since Friday 11/22. I know that there needs to be much more time for the boiler to function in order to make any assumptions, but so far so good. From what has been written on this forum, there is not a one time fix for the problem of explosions and each case needs to be handled individually. Darren feels that I have made changes via rewiring the dump motor to run only with the fan and slowing the motor with the rheostat has accomplished what the retrofitted ash dump controller will do. I spent $25 for the rheostat and the motor rewiring was free. So we will have to see what the cost from AHS will be for the retrofit. I am not recommending that anyone make the changes to your boiler that I did without first consulting with AHS or another expert. I am just a frustrated coal boiler owner trying my best to make the boiler safe for my family and I am happy the AHS is finally helping me. I'll keep everyone posted.

Larry, the guy's trying to solve current, realistic problems for people. Even this dumb ass farmer knows what "I would not add the kit to a boiler that is working well"

lsayre wrote:What is different with the later models ashing operation vs. my chain drive version that would make them potentially more prone to puff-backs? It shouldn't matter much how the ash grate is being actuated (as in chain drive or direct drive), as long as its being turned on at the same temperature and by the same LC and thermocouple, and ditto being off at the same temperature, and its moving in and out at the same relative speed.

What I'm attempting to do here is find out why my somewhat older model works and the newer models don't work. My entire line of questioning is directed to that end. I have no desire to apply a fix when I don't need it, and when AHS is advising me against it. I'm asking why I don't need it. If my system has something different about its ash drive (speed of stroke, length of stroke, initiation of stroke, termination of stroke, etc...) and mine works, it seems that rather than add on a bolt on electrical kludge, the straight forward solution would be to retro the newer models back to the way the older models (the ones with fewer problems) work.

it seems that rather than add on a bolt on electrical kludge, the straight forward solution would be to retro the newer models back to the way the older models (the ones with fewer problems) work.

Except the chain drive did create maintenance issues. Reliability also, if the chain was not maintained. The newer setup is simpler and less costly to manufacture, even with the mode switch added in. The early direct drive systems' grate speed was higher than optimum, and much higher than with the chain drive. Now the grate speed can be electronically controlled with great flexibility.

A change of sprockets would be an easy enough fix for the chain drive models.

coaledsweat wrote:A change of sprockets would be an easy enough fix for the chain drive models.

That may be easier said than done.... My buddy's has the teeniest sprocket ever invented on the motor and a wall scraping bad boy driven.