Pilot mode airflow..? unbured coal!

Pilot mode airflow..? unbured coal!

PostBy: Coalbrokdale On: Thu Apr 03, 2008 11:39 am

Hey guys, I have to take pictures of the VF3000 install and post them, she is running I'm just trying to get it dialed in...

I have questions about the the Air flow?
1st - What are you guys doing with the restrictor plate, mannual says nothing about it, but I installed in on the Combustion blower, I keep it full open. should it be damped down? I guess it swings open and close on one of the screws......? last night I closed down the restrictor plate and kept a med to large fire on the feeder, when I checked this morning fire looked good no coal in the ash but the boiler temp was down to 125 degrees. Normal is 180-185.

2nd - When the the boiler enters pilot mode I get unburned coal in the ash which I have heard is normal..? not going bellow 5 minutes on time.

3rd - Is is bad to adjust it to keep it running no stop? no pilot mode..?

4th - I was thinking it would be great if I could setup a second fan that would run at a slow speed/airflow in pilot mode to keep all the coal buring, since it seems the lack of air is what cases the unburned pieces of coal.

My draft seems good have not measured it yet, but the stove pipe is staying rather cool, it never get's above 180, and drops to 120 ish... It pulls a nice draft as I check it with a lighter, and it pulls the flame through the baro-damper.
Coalbrokdale
 
Stove/Furnace Make: Harman \ Coalbrookdale
Stove/Furnace Model: VF3000 \Darby

Re: Pilot mode airflow..? unbured coal!

PostBy: LsFarm On: Thu Apr 03, 2008 11:54 am

You definintely should get on the Manometer Loaner program.. PM Matthaus he is keeping track of the two Manometers in circulation.. here is the thread about the program: Manometer Loaner Program
Checking with a flame to confirm that you have a draft is fine... but the Manometer allows you to adjust the draft to what your boiler's manufacturer recommends. You can make a rough adjustment using the numbers on the 'V' shaped bracket with the slots.. Make sure you have the barometer set up correctly,, there is a vertical mode and a horizontal mode.

Yes, a small fan running all the time pushing some air through the coal will reduce the unburnt coal during pilot mode. Matthaus and several other users of the Harman stoker system do something like this. Maybe they plug the combustion fan into a full time outlet?? I can't remember.

The setting of the restrictor plate is a trial an error process. You said your water temp was down this morning... I assume that the stoker was running, but not producing enough heat? When did you see this reading?? was it after several people took showers, and the heat was turned up in the house?? When there is a large BTU draw on a coal boiler, it takes a while for it to catch up, to build up a bigger coal fire, and burn that coal. So there is lag during the recovery. So make sure you were seeing the boiler in a resting mode, not after several showers pulled the water temp down.

I thihk Matthaus is out of town, but he will get online once or twice a day for the rest of the week.

Greg L
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Re: Pilot mode airflow..? unbured coal!

PostBy: WNY On: Thu Apr 03, 2008 11:56 am

Most combustion blowers run 24/7 and have no restrictor plates, other have them. My Hyfire does not have them, but my keystoker does and both run constantly?

If you had a manometer (Get on the Loan Program here) to check your actual draft, then you can set the blower to produce the desired amount at full burn and idle.

I know the boilers are a bit different and some have 2 blowers for low/high or multi speeds for the combustion blower(s).

Sounds like you are getting it close (dialed in)
WNY
 
Hot Air Coal Stoker Stove: Keystoker 90K, Leisure Line Hyfire I
Coal Size/Type: Rice
Stove/Furnace Make: Keystoker, LL & CoalTrol
Stove/Furnace Model: 90K, Hyfire I, VF3000 Soon

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Re: Pilot mode airflow..? unbured coal!

PostBy: coalkirk On: Thu Apr 03, 2008 1:49 pm

Coalbrokdale wrote:Hey guys, I have to take pictures of the VF3000 install and post them, she is running I'm just trying to get it dialed in...

I have questions about the the Air flow?
1st - What are you guys doing with the restrictor plate, mannual says nothing about it, but I installed in on the Combustion blower, I keep it full open. should it be damped down? I guess it swings open and close on one of the screws......? last night I closed down the restrictor plate and kept a med to large fire on the feeder, when I checked this morning fire looked good no coal in the ash but the boiler temp was down to 125 degrees. Normal is 180-185.
I've ranted on this forum in the past about the VF3K manual. When I first fired mine up, I filled the house with CO due to the restrictor plate or I should say the lack of the restrictor plate. I emailed annd called Harman about the lack of any mention in the VF3K manual regarding this part and the potential for problems such as I had experienced but got no response. Are you getting any coal gas odor in the house when the boiler is firing? What happpened in my case was the combustion blower was essentially overpressuring the combustion chambber and coal gas was being expelled out the feed through the hopper. Once i installed that nagging left over part(restrictor plate) and adjusted it, no more problem. There's not even a picture or part number in the expolded view parts picture.

2nd - When the the boiler enters pilot mode I get unburned coal in the ash which I have heard is normal..? not going bellow 5 minutes on time.
That's unavoidable. It bothered me at first but you've got to rationallize that you're saving lots of $ antway. You can minimize by making sure you're not pushing to much coal. I've got my feed adjusted at about 2 1/2 dots. I've got my on time at 4 minutes and my off time at 15 minutes.

3rd - Is is bad to adjust it to keep it running no stop? no pilot mode..?
No, it's not bad but there is a balance between running the fan, how much and how often you push coal that has to be resolved. I moslty just let mine cycle but a few times during very heavy demand, i ran the fan constantly.
4th - I was thinking it would be great if I could setup a second fan that would run at a slow speed/airflow in pilot mode to keep all the coal buring, since it seems the lack of air is what cases the unburned pieces of coal.
Some guys are using the coal-trol controller to give you more control over how dialed in you can get the boiler to burn. i'm happpy with my results but your heating demands may make it more desirable.

My draft seems good have not measured it yet, but the stove pipe is staying rather cool, it never get's above 180, and drops to 120 ish... It pulls a nice draft as I check it with a lighter, and it pulls the flame through the baro-damper.

Get on the Baro loaner thread and set your draft with it. It can be a real savings when you arn't sending too much heat up the stack.
coalkirk
 
Stoker Coal Boiler: Harman VF3000
Coal Size/Type: antrhcite/rice coal

Re: Pilot mode airflow..? unbured coal!

PostBy: LsFarm On: Thu Apr 03, 2008 4:01 pm

coalkirk,, approximately where did you set the restrictor plate?? I'm assuming this is a pivoting plate that can leave the inlet to the fan un-restricted or fully covered... So approximately how much of the inlet did you cover with the plate?? 1/2? 3/4? or??
I know this will vary a lot with draft, quality of coal, tightness of the house etc.. But it may give Coalbrookdale a starting point... it sounds like he covered too much of the inlet..

Greg L

.
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Re: Pilot mode airflow..? unbured coal!

PostBy: Highlander On: Thu Apr 03, 2008 6:04 pm

1st - What are you guys doing with the restrictor plate, mannual says nothing about it, but I installed in on the Combustion blower, I keep it full open. should it be damped down? I guess it swings open and close on one of the screws......? last night I closed down the restrictor plate and kept a med to large fire on the feeder, when I checked this morning fire looked good no coal in the ash but the boiler temp was down to 125 degrees. Normal is 180-185.


I run without a restrictor plate now, I did initially have it, and ran with it about half open, but have since modified the design, using a two speed approach for the combustion air. When stoking the fan runs full tilt, and runs at a reduced speed when not. It seems to work for me. If you want to get maximum heat out of your boiler, than you have to run with it fairly wide open, closing it down will reduce the maximum firing level you can achieve.


2nd - When the the boiler enters pilot mode I get unburned coal in the ash which I have heard is normal..? not going bellow 5 minutes on time.


I get unburned coal too, it doesn't seem to matter whether it is in warm or cold, I've concluded it must be shale or some unburnable coal.


3rd - Is is bad to adjust it to keep it running no stop? no pilot mode..?


Pilot mode is really just the minimum firing rate that will maintain a fire for a long time. Ideally you want your pilot mode settings to use as little coal as possible, or maybe to maintain a certain minimum water temperature in the boiler. If you don't run the blower constantly, then you rely on the natural draft of the chimney to pull enough air through the fire to maintain it. I've had much better results letting the blower run 24/7, and never had an outfire in the warmest parts of the summer months when my draft at the breech went down to about .02".


4th - I was thinking it would be great if I could setup a second fan that would run at a slow speed/airflow in pilot mode to keep all the coal buring, since it seems the lack of air is what cases the unburned pieces of coal.
I get unburned coal too, this last load seems to generate more than previous loads. I haven't seen any less unburned coal when we were in the peak of the heating season so I suspect its just shale or unburnable coal. Its not that much, but it is noticable.


Try using a fan speed controller to run the blower at a slower speed when not stoking, I think you'll find this does exactly that.

My draft seems good have not measured it yet, but the stove pipe is staying rather cool, it never get's above 180, and drops to 120 ish... It pulls a nice draft as I check it with a lighter, and it pulls the flame through the baro-damper.


My draft is very similar, .05-.06 when she's cooking, down to about .02 when idling and the wind isn't blowing. The draft over the fire runs about .04-.05 or about .01 less than at the breech. The pipe is just warm to the touch when idling.

Post some Pix, would love to see how it turned out.

Bill A.
Highlander
 
Stoker Coal Boiler: Harman VF3000
Hand Fed Coal Stove: Vermont Castings Resolute
Coal Size/Type: Rice
Stove/Furnace Make: Harman
Stove/Furnace Model: VF3000 Stoker Boiler

Re: Pilot mode airflow..? unbured coal!

PostBy: coalkirk On: Thu Apr 03, 2008 6:41 pm

LsFarm wrote:coalkirk,, approximately where did you set the restrictor plate?? I'm assuming this is a pivoting plate that can leave the inlet to the fan un-restricted or fully covered... So approximately how much of the inlet did you cover with the plate?? 1/2? 3/4? or??
I know this will vary a lot with draft, quality of coal, tightness of the house etc.. But it may give Coalbrookdale a starting point... it sounds like he covered too much of the inlet..

Greg L

.

My restricter plate is about half open. To really set things correctly you are going to need to get a manometer.
coalkirk
 
Stoker Coal Boiler: Harman VF3000
Coal Size/Type: antrhcite/rice coal

Re: Pilot mode airflow..? unbured coal!

PostBy: 1975gt750 On: Thu Apr 03, 2008 8:29 pm

where can you buy one of those fan speed controllers i would like to try that on my keystoker to slow the fan down. does the fan speed controller lower the voltage to the blower and if it does that could be bad for the blower motor. i get no unbured coal i ma y ash no matter if it is running full boar or just idling away

chris
1975gt750
 
Stoker Coal Boiler: keystoker kaa-2
Coal Size/Type: rice coal / blaschak
Other Heating: pensotti oil boiler with riello 40 burner
Stove/Furnace Make: keystoker
Stove/Furnace Model: kaa-2

Re: Pilot mode airflow..? unbured coal!

PostBy: Highlander On: Thu Apr 03, 2008 9:15 pm

where can you buy one of those fan speed controllers i would like to try that on my keystoker to slow the fan down. does the fan speed controller lower the voltage to the blower and if it does that could be bad for the blower motor. i get no unbured coal i ma y ash no matter if it is running full boar or just idling away


They are readily available at Home Depot or Lowes or any other hardware chain that sells electrical supplies. The ones I bought are used to vary the speed of ceiling fans, and are good for a couple of hundred watts, plenty for the small combustion air blower.
Highlander
 
Stoker Coal Boiler: Harman VF3000
Hand Fed Coal Stove: Vermont Castings Resolute
Coal Size/Type: Rice
Stove/Furnace Make: Harman
Stove/Furnace Model: VF3000 Stoker Boiler

Re: Pilot mode airflow..? unbured coal!

PostBy: Coalbrokdale On: Fri Apr 04, 2008 11:19 am

Here's my thinking for a simple pilot blower setup...

I'm considering bolting another fan to the current Combustion fans intake, leaving a gap between the 2 fans, and running it constantly at a much restricted airflow. I figure I can tweek the 2 fans with washers and restrictor plate(s) so when aquastat clicks off the feeder and main combustion blowers, the add-on fan will force just enough air the through the stopped main fan to provide a nice pilot burn. Then I can adjust the on off times to keep the fire going. When there is a large call for heat, it will ramp up faster. I just need to be sure I'm not pushing to much air, which should be easy enough..

Made these notes on the train this morning:
The idea is to:
1st - find a nice strong feeder and blower setting which creates a fast recovery time.
2nd - with a second blower motor (pilot-fan) blowing at the primarys' intake use washers to create a space between the intake and pilot fan. This will prevent the primary fan from having any restriction.
3rd - wire the pilot fan to run nonstop and restricted, providing just enough air to keep the coal buring while the pusher pushes enough coal to prevent the fire from going out and not so much as to create to much heat or dump hot coals off the edge...
Coalbrokdale
 
Stove/Furnace Make: Harman \ Coalbrookdale
Stove/Furnace Model: VF3000 \Darby

Re: Pilot mode airflow..? unbured coal!

PostBy: Matthaus On: Fri Apr 04, 2008 8:57 pm

Coalbrokdale wrote:Here's my thinking for a simple pilot blower setup...


I think will work nicely, you might want to run the pilot (secondary) combustion fan with a speed control that way you can get the burn correct while using less power ( as opposed to a plate over the intake which just makes the fan run full speed but restricts the air and increases the static pressure and also restricts the intake to the main combustion fan). This will also allow you to eliminate the spacers between fans (I think).

Have fun with the science project, keep us posted. :)
Matthaus
 
Stoker Coal Boiler: Leisure Line WL110 Dual Fuel
Hot Air Coal Stoker Stove: Leisure Line Lil' Heater (rental house)
Coal Size/Type: Rice and Buckwheat Anthracite

Re: Pilot mode airflow..? unbured coal!

PostBy: Dutchman On: Fri Apr 04, 2008 9:47 pm

My first year with the Mag I had everything running on the Harman controller, this year I took some advice and plugged the combustion fan into a live outlet- BIG difference in my mind- much more complete burn than cycling the fan on/off/on/off etc, especially when she's idling for extended times.

That restrictor plate, it attaches to one of the screws on the intake side of the blower, and then swivels open or closed as needed. Usually once a month for me to check and adjust since I have cat hair to clean off the intake screen. I monkeyed with setting it initially till I got a fire that looked bright but without blowtorch flames, that was open between 1/4 and 1/2 way. Bought a Dwyer Mark II for this season, and that helped a great deal in setting the plate and baro better.

I have no idea how similar the setup is between the Mag and the VF3000, but here's what the owner's manual says for the Mag. The first sentence, they have a picture of the meter installed between the top of the stove and the baro damper:

With the stove burning hot and stabilized set barometric damper at .04 to .06 on the draft meter. Next take a reading in the fire box by removing the bolt in the front center of the unit. Start the conbustion blower. While watching the draft meter, close the restricter plate on the combustion blower slowly, until the needle reads about the same as it did on the flue. An example would be a flue reading of .05 and a firebox reading of .02. Close the restricter plate until the firebox reading is .04 to.05. Closing the restricter plate will reduce the positive pressure from the blower and increase the negative pressure in the firebox.

(I love my Mag, it's a shame Harman can't use a spell-checker :lol:)
Dutchman
 
Hot Air Coal Stoker Stove: Harman Magnum
Coal Size/Type: rice/anthracite

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