flat bed [KAA2] vs sloped bed stokers

flat bed [KAA2] vs sloped bed stokers

PostBy: dave brode On: Tue Nov 19, 2013 11:19 pm

All,

The Kaa2 has a flat bed. The larger Keystokers have quite a bit of slant to their beds. It seems to me that the coal would move so much better [and not get so densely packed] if the Kaa2 had a little slope too.

I believe that one could modify the stoker on the Kaa2 to makes the bed slope down 5 or so degrees. The mounting flage could be repositioned/rewelded, and the top opening cut so the hopper would still fit.

Yes, I have tinkeritis. Do I need help?

Dave
dave brode
 
Stoker Coal Boiler: Keystoker KAA-2
Hand Fed Coal Boiler: used to have a 5 section Red Square
Coal Size/Type: rice anthracite

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: KLook On: Tue Nov 19, 2013 11:41 pm

I believe you are at stage 3 and very close to 4. Collecting them is the final stage of madness. :shock:

Kevin
KLook
 
Stoker Coal Boiler: Harman VF 3000
Coal Size/Type: rice, bagged, Blaschak
Stove/Furnace Make: Harman (Back In Maine)
Stove/Furnace Model: VF 3000

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: Rob R. On: Wed Nov 20, 2013 7:05 am

There must be a reason for the design difference between the stokers.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Visit Lehigh Anthracite

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: dcrane On: Wed Nov 20, 2013 7:06 am

Is the feed mechanism, air induction, etc. the same design on all models?
dcrane
 
Hand Fed Coal Stove: Crane 404

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: Rob R. On: Wed Nov 20, 2013 7:12 am

dcrane wrote:Is the feed mechanism, air induction, etc. the same design on all models?


No. The KA-6 and larger units have multiple grates mounted on an incline, the stoker also has two blowers...one is small and runs all the time to keep the fire burning in low-draft situations, the other is the main combustion blower.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: Rob R. On: Wed Nov 20, 2013 7:25 am

I can't find a picture of the feed mechanism on each style stoker, but that is different as well. Just my opinion, but the KAA-2 stoker seems to be much lighter duty compared to its bigger brothers. I don't care for the use of nylon components in the stoker... but I admit that there are a lot of them running and I have heard of very few problems.
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Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: Carbon12 On: Wed Nov 20, 2013 7:40 am

Doesn't the KA2 have a nylon cam of some sort? Placing the carpet at an incline may direct heat towards that cam which can melt.
Carbon12
 
Stoker Coal Boiler: Keystoker KA-6
Coal Size/Type: Rice/Anthracite
Other Heating: Heat Pump/Forced Hot Air Oil Furnace

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: oliver power On: Wed Nov 20, 2013 7:50 am

All I know is; I have no problems what so ever with my Kaa-2. I don't want to fix something that's not broke. However, I am curious of your findings.
oliver power
 
Stoker Coal Boiler: KEYSTOKER Kaa-2
Hand Fed Coal Stove: Hitzer 50-93 & 30-95, Vigilant (pre-Vigilant-II)
Baseburners & Antiques: MANY (Mostly when burning wood)
Stove/Furnace Make: HITZER / KEYSTOKER
Stove/Furnace Model: 50-93 & 30-95 , Kaa-2

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: Rob R. On: Wed Nov 20, 2013 7:56 am

With the relatively small amount of coal being fed onto the grates of the KAA-2, an incline might result in the coal bed being very shallow and the air passing through it inefficiently. Just a guess.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: Rob R. On: Wed Nov 20, 2013 7:58 am

oliver power wrote:All I know is; I have no problems what so ever with my Kaa-2. I don't want to fix something that's not broke. However, I am curious of your findings.


I was hoping you would jack up the back of the boiler and report back with the results. :lol:

I am pretty sure Keystoker made it the way it is for a very good reason.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: blrman07 On: Wed Nov 20, 2013 8:28 am

The nylon cam helps to act as a safety device. In the event of a burnback on the grate the cam will heat up and melt stopping any further feed of coal thereby preventing a full out hopper fire. I have changed quite a few on Keystoker units of all sizes. In each case the seal around the grates was compromised and was allowing coal to burn back up the grate. It's easy to change and works good.


Rev. Larry
blrman07
 
Hand Fed Coal Boiler: Bucket a Day
Hand Fed Coal Stove: Vigilant Casting 2310
Baseburners & Antiques: rebuilding a 1906 March Brownback Double Heater, reblacking a UMCO 1920's Pot Belly
Coal Size/Type: Pea/Nut/Wood in the VC and anything that will fit in the Bucket a Day. It's not fussy.

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: stovepipemike On: Wed Nov 20, 2013 8:43 am

My guess is that the fuel bed in a larger stoker may not allow the incoming coal to push the pile ahead of it without "bunching"due to the weight of the pile without the help of gravity. The KAA2 has a relatively short small grate area and is not as affected by a larger volume of coal. My $0.02 Mike
stovepipemike
 
Stove/Furnace Make: Keystoker
Stove/Furnace Model: KAA-2

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: dcrane On: Wed Nov 20, 2013 9:58 am

Rob R. wrote:
oliver power wrote:All I know is; I have no problems what so ever with my Kaa-2. I don't want to fix something that's not broke. However, I am curious of your findings.


I was hoping you would jack up the back of the boiler and report back with the results. :lol:

I am pretty sure Keystoker made it the way it is for a very good reason.


agree with Rob... if these models are indeed different designs, mechanics, drafts, etc... I can only assume this has been tested and their are reasons why its done this way. But I do like your thought process and your tinkeritis addiction :clap:
dcrane
 
Hand Fed Coal Stove: Crane 404

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: oliver power On: Wed Nov 20, 2013 6:29 pm

blrman07 wrote:The nylon cam helps to act as a safety device. In the event of a burnback on the grate the cam will heat up and melt stopping any further feed of coal thereby preventing a full out hopper fire. I have changed quite a few on Keystoker units of all sizes. In each case the seal around the grates was compromised and was allowing coal to burn back up the grate. It's easy to change and works good.


Rev. Larry
Hi blrman07, I don't think the other size boilers have any nylon cam. As far as I know, it's only the Kaa-2 that has the nylon cam. I'm not familiar with other size boilers. I do know they have complete different stokers in them. I do believe the stoker in the Kaa-2 is the same stoker used in one of Keystoker's stoves. The Kaa-2, I believe, came out AFTER the stove. Maybe the angle of the stoker has something to do with the stoker stove.
oliver power
 
Stoker Coal Boiler: KEYSTOKER Kaa-2
Hand Fed Coal Stove: Hitzer 50-93 & 30-95, Vigilant (pre-Vigilant-II)
Baseburners & Antiques: MANY (Mostly when burning wood)
Stove/Furnace Make: HITZER / KEYSTOKER
Stove/Furnace Model: 50-93 & 30-95 , Kaa-2

Re: flat bed [KAA2] vs sloped bed stokers

PostBy: dave brode On: Wed Nov 20, 2013 9:55 pm

Gents,

Yes, the smaller flat bed unit is much less "industrial like". Fwiw, I smear the nylon roller with high temp anti-seize, and lube the pusher all four sides with same. The nylon screws used as guides are a little mickey-mouse imo. The gap on the adjusted side allows fines will build up around the pusher, and cause binding. That said, I've had no issues with mine.

You can test for binding by adjusting the white screw all the way out. this allows moving the pusher in/out by hand to judge friction.

Back to topic, Here's a pic of the larger sloped bed, just down from top of page;

http://keystoker.com/products.php

Mid way down, exploded view. Note four grates;

http://keystoker.com/manuals/2012/A-250-A-350-A-450.pdf

I can't find a pic of the flat bed, but it really isn't all that much smaller. Stovepipemike used the term bunching up. That's my point. I wonder if a little down angle on the bed would allow the coal to push easier, and therefore be less densely packed on the bed = better burn.

I know, it ain't broke, but I fix things often, and then re-fix them back. LOL

Dave
dave brode
 
Stoker Coal Boiler: Keystoker KAA-2
Hand Fed Coal Boiler: used to have a 5 section Red Square
Coal Size/Type: rice anthracite

Visit Lehigh Anthracite