LL AA-220 Relocation

lsayre wrote: ↑

Thu. Nov. 29, 2018 10:38 am

That said, the thinking that if it fired for 7 hours out of ten it should have consumed 7 x 18 lbs. of coal = 126 lbs. within a span of those same 10 hours is also wrong thinking.

I am of the opinion that each appliance and installation has a 'base level' of consumption that yields near zero benefit. The larger the appliance, the larger the base.

But larger bases have larger potential, not just based on surface area, but that's a big part.

Think of it like a campfire. The more kindling and larger the base of the fire, the bigger and hotter you can build it. Some are camp stoves that need slivers of wood added a little at a time, others are bonfires where you can toss in 5 foot sections of full size logs and not slow it down

lsayre wrote: ↑

Thu. Nov. 29, 2018 10:26 am

If you increase the coal feed beyond the factory max, will the stoker blowers need to be changed out for blowers with more CFM, or do they have plenty of reserve?

I think I would run out of draft before I could burn more than the blowers could put out. Right now the gates are about 35-40% open.

lsayre wrote: ↑

Thu. Nov. 29, 2018 10:38 am

That said, the thinking that if it fired for 7 hours out of ten it should have consumed 7 x 18 lbs. of coal = 126 lbs. within a span of those same 10 hours is also wrong thinking.

You lost me here, please explain. Could be why my consumption is fluctuating a little bit. I have seen 8.8 through 10.2lbs per hour. Everyday is a little different but usually within a pound. Been mid 9's last couple days.

CoalisCoolxWarm wrote: ↑

Thu. Nov. 29, 2018 10:56 am

I am of the opinion that each appliance and installation has a 'base level' of consumption that yields near zero benefit. The larger the appliance, the larger the base.

But larger bases have larger potential, not just based on surface area, but that's a big part.

Think of it like a campfire. The more kindling and larger the base of the fire, the bigger and hotter you can build it. Some are camp stoves that need slivers of wood added a little at a time, others are bonfires where you can toss in 5 foot sections of full size logs and not slow it down

I understand, I have 2 stokers running so if you lumped both of those fires together it still seems smaller than say the mass of a 520. What's the diameter of a AHS 260? Would have to be a pretty good size mass of burning coal?

swyman wrote: ↑

Thu. Nov. 29, 2018 12:00 pm

You lost me here, please explain. Could be why my consumption is fluctuating a little bit. I have seen 8.8 through 10.2lbs per hour. Everyday is a little different but usually within a pound. Been mid 9's last couple days.

The stoker is not instant on and off like oil or propane or NG. It takes time to for it ramp up from idle capacity to full capacity, which it will do progressively. So it will not often reflect its full potential for consumption capacity via a timer.

The longer it runs without hitting the high limit and cutting off, the more chance you have that it will achieve its full rated capacity. It is not cold enough outside for this potential to exist yet. The colder it gets, the more likely it is that at some juncture (most likely to be on one of the seriously coldest days of the year) it will actually have ramped up to full maximum input/output and kept itself at that level for awhile. I don't have this type of stoker, but it is my understanding that at full guns feed it will have a blowtorch of a fire that extends out to within about 1/2" or less of having active fire falling into the ash tub.

Thank you Larry, got it! That is where I always faltered before. I could run the fire right off the table because I could not get enough draft to turn the blowers up so I had to slow the stokers down. This year I have the stokers wide open and had to slow the blowers down! A far better scenario in my opinion!

You may one day come to find that at full guns it is actually conservatively rated at 220,000 BTUH input. But hopefully you won't ever actually need that level of heat, as it will really eat through the coal.

swyman wrote: ↑

Thu. Nov. 29, 2018 7:21 am

Only thing I can think of is with the carpet feed system, rice and buck would have to feed different. I do have 3 ton of rice left over from last season but lot of work to change over, not feeling it.

Yes, that is a fact. The size of coal you are running directly effects the "pounds per hour" feed rate. Smaller coal increases the feed rate, larger coal reduces the feed rate. There is an example of this in the EFM 520 manual, Rice is 2.5 pounds per hour per tooth and Buckwheat is 2 pounds per hour per tooth of feed rate. This principle applies to every coal stoker I have come across.

One thing to keep in mind on your boiler is that the carpet feed stokers seem to have an inconsistent feed rate. The have no coal pusher, just the moving carpet that kind of shuffles the coal and ash down the grate. The feed rate on these can be effected by the condition of the Strongback gasket and fines getting under the carpet. Even the amount of coal pushing down from the hopper can effect the feed rate to some extent.

-Don

I burn and waste much less coal using the buck rice mix that they load in my dump trailer every month. my stoker is set at 11 threads out.

StokerDon wrote: ↑

Fri. Nov. 30, 2018 9:25 am

One thing to keep in mind on your boiler is that the carpet feed stokers seem to have an inconsistent feed rate.

-Don

I get a different reading everyday, within +- 2lbs per whatever hour period.

StokerDon wrote: ↑

Fri. Nov. 30, 2018 9:25 am

One thing to keep in mind on your boiler is that the carpet feed stokers seem to have an inconsistent feed rate. The have no coal pusher, just the moving carpet that kind of shuffles the coal and ash down the grate. The feed rate on these can be effected by the condition of the Strongback gasket and fines getting under the carpet. Even the amount of coal pushing down from the hopper can effect the feed rate to some extent.
-Don

Pay heed here to what is being said...your exact symptoms fit the "fines under the carpet" to a "T".
Do not ignore even a small amount of fines under the carpet, especially when burning rice...using smaller coal is worse than bigger coal.
How do fines get there?...If that steel carpet gets hot even one time from a stalled carpet and it gets even a tiny bow in either direction...front-back or even left-right and fines get under it then it will lift it where it cannot afford to lift and pushing will be greatly impaired...carpets are designed to slide tight and flat...no gap what so ever.

The fact that you are seeing an improvement with now switching to buckwheat is blatant proof that this condition exists.

McGiever wrote: ↑

Sat. Dec. 01, 2018 7:57 pm

The fact that you are seeing an improvement with now switching to buckwheat is blatant proof that this condition exists.

I think there will be inconsistencies with this type of feeding system no matter what. How does this fed system actually work. Does the edge of the carpet grab and push the coal into the stoker bed or does the material on top of the carpet kind of ride out onto the stoler bed and drop off as it returns? I used this concept at work building a bolt feeder for the assembly line but my carpet was near vertical and used the edge to lift the bolts out of the bin. But this being in a horizontal position I could see the material riding on the carpet if that makes any sense?

Was a good day off yesterday. Got some t-stat wire and insulation for my 1" copper in the ceiling of the garage. I had not been up there in years and I have 60' total of copper run that just had a 18" wide piece of single faced wall insulation laying over it like a blanket. I bought the foam with sticky tape and put over the pipes and then put the fiberglass blanket back over it. Has to help I would think? Need to wire the relay and hook up in the taco controller and I will be good to go for the garage loop. Bought a box so I will be able to install a t-stat in the barn to control the modine and circulator. Going to add more insulation out there also, where it transitions from the ground to the inside of the barn.

Good idea on the insulation!

1" loses a lot of heat, 3/4" loses more, 1/2" loses even more.

Once you get 1.25" and 1.5" the loses are a fair amount LESS.

As the diameter increases, the flow concentrates in the center, with the outside water (closest to the inner wall of the piping) "sleeves" the inside water and 'insulates' it. Well, not exactly insulates in the strictest sense, but the heat loss is less. Same general idea

PEX is better than copper.

Even better, cover that new pipe insulation up with some house insulation. It's cheap and effective!

Really glad to hear of your (nearly) daily improvements! Keep up the good work.

swyman wrote: ↑

Mon. Dec. 03, 2018 9:57 am

How does this fed system actually work.
Does the edge of the carpet grab and push the coal into the stoker bed
or does the material on top of the carpet kind of ride out onto the stoker bed and drop off as it returns?

Well, some of both, I'd say. Nudge pieces forward and then slide back to retract and then repeat to nudge.

My point is that as soon as that first crumb works it way underneath carpet it is a chain-reaction with more and increasingly bigger crumbs until you have lost any of your good or accurate adjustments for feeding due to the gap and how carpet edge now makes contact with coal particles...could this reduce the factory lbs/hr coal feed rate???

As for switching to a bigger coal particle size (buckwheat) it could be seen as a "crutch" to get by due to it's bigger particle size and how the carpet edge moves this larger coal...one would think in eventuality some of the smaller buckwheat particles will possibly find their way under the carpet if this is even possible.

Bottom line...best to know and always maintain a perfectly flat tight carpet as I stated above in a prior post already .

BTW: The warp and particle gap under a carpet does allow a small amount of air introduction where it is not desired...and unchecked can cause a little burn back which can make the carpet again too hot and just warp even more...if you want stoker to run as factory new, keep or maintain stoker as factory new.