More Babble -Setup for Variable Stoker Feed Rate Keystoker

More babble -setup for variable stoker feed rate Keystoker

PostBy: dave brode On: Sun Feb 26, 2012 12:49 pm


Talking Keystoker type flat bed stoker. I'm looking at my Kaa2, but this could apply to others. Yes, I have tinkeritis. But, slow boiler temp recovery is an issue for many of us.

Objective: quicker recovery when boiler gets a call from 'stat. My boiler recovers quicker with the stoker set at full stroke. Of course full stroke can't be used for normal hard running. My proposed setup would allow full stroke for a set time period at the onset of a call for heat, so the bed fills quicker. After set time period, stoker feed rate would return to a normal feed rate [usually 1/2 to 3/4 of stoker capacity].

How to accomplish:

Seperate stoker and combustion fan wiring. Wire blower to run any time boiler is powered up. The factory supplied timer would still control the stoker for idle fire only. A lesser number of "pins" should allow full stroke setting to be used. Use a 2nd timer, powered from 'stat [but not the timer], to cycle stoker on/off during steady running to allow intermittent full stroke feed rate, to allow for a normally required feed rate for a steady run fire.

To allow steady full stroke for a time period at onset of call;

Use a timed relay of some sort to allow continious full stroke action for a time period at onset of a call to allow filling bed quicker. In other words, use a part time circuit to bypass the 2nd timer that cycles stoker motor.

Control options:

The 2nd timer could be the same as the factory supplied timer, or any number of options out there for cycle timers. To run the stoker at full stroke for a time period for quick bed fill, it looks like a single shot, "switch on initiated interval relay" would work. See wide range timing function #7096K224; ... ys/=gf25m3

Another option would be a $10 delay on timer, controlling an NC relay, but the above looks simpler to me.

Fyi, keystoker wiring:

Ok, let me have it. Flame proof suit on.

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