Bob wrote:mikeandgerry wrote: I keep a thinner fire because I don't have the load you do
What do you mean by a "thinner fire"? How do you control the thinness of the fire in the AA boiler?
It is not really something you can observe with the AAA. In general I am only referring to controlling the average size of the fire for variable heat output.
In the 130-m you have an 11" diameter fire pot over a reciprocating grate. Above the fire pot is the coal feed tube. It is one column of fresh coal, on top of a burning fire, on top of a bed of ash. All of that is like the AHS. Bear in mind I haven't seen an AHS but Yanche has written extensively about his so I know that the grate drive mechanism is different. Anyway, the feed tube of the AAA has a large cam (offset lobe on the tube) that reciprocates a rod that drives a ratchet that reciprocates the grate. The rod can be driven different distances by adjusting the "shake adjuster" which is a slide stop that regulates how far the cam drives the rod turning the ratchet. The result is that you can adjust the number of teeth taken on the grate ratchet from one to three. This determines the rate at which the grate reciprocates (known as "shake" to AA) and thus how fast the coal feeds through the system. One tooth is minimum (the grate must reciprocate), three is maximum throughput. One tooth is a thinner fire, three is a thicker fire (bigger fire).
The other aspect of fire size control is the anthrastat. The AHS has an ash sensor which Yanche has indicated is superior to the radiant sensing thermostat (anthrastat) that the AAA has. I don't know the difference but the result is the same; Setting the anthrastat to a higher temperature keeps the fire pot thicker with fire, i.e. a bigger average fire. The grate will shake longer until fire gets closer to the grate satisfying the higher anthrastat setting and shutting off the movement of the grate. The result is a thicker fire in the pot.
Also, try the AA Anthratube information library that Yanche was so kind to post on the web.
Hope it helped.