Coalgun- Puff backs & Explosions

Re: Coalgun- Puff backs & Explosions

PostBy: whistlenut On: Fri Dec 28, 2012 11:35 am

Larry, yes I will share some of the 'experience' lessons. Steam-up......man can we all relate to being blown on our butts with a hand fed 'puff-back' when you learn to 'crack' the door...on wood or coal rigs. The wood-gun is one hell of an efficient machine, and probably we would all consider that technology if there were no coal to burn.....however coal is available, and it is DIFFERENT from batch to batch. Close enough to be able to keep similar settings.

Draft....the most important word to consider(and the ability to maintain an air source to allow for a draft)
Think of an oil boiler for a second. What technology is now required for a SAFE, CLEAN IGNITION? BEFORE AND AFTER.....THINK......
Control of the air is essential, and velocity of that air. Are coal gasses volatile ? If you have to ask, go to the outhouse, you are too dumb to go any further...........
Familiar with LEL (lower explosive Limit?) and the % required to make the situation a newspaper headline? How about UEL (upper explosive limit)?
Knowing how to operate within these acceptable parameters constantly, is the key to success.

When lighting a charcoal fire, do you soak the brickettes (if they are not already done), or do you just squirt from the lighter fluid container....and toss a book of lit matches in the general direction?????? Can you see where this is going.......????????

Don't trouble your complicated mind right now...just think about it. ...and yes, I have burned a beard, eyebrows, arms, and been knocked on my arse more than once......and I would gladly trade those experiences for less scars, less broken bones, less cuts and less burns, but that can't be altered. The hand-fed guys are tough bastards....simply because they LOVE livin' on the WILD SIDE! (had to get a dig for Freetown Fred---You da man, Fred!!!)

I went from the Itasca 415 direct to an AA 130 and a 260. Steep learning curve, but back then I had the muscles to hang on....now I prefer a quieter presence. The scars remain, the fractures are healed, and the surgeries have been successful, most mental functions are OK, but even that has been questioned many times here on the forum.......

Freddy has the cure...and it could be more universal in a kit......it all costs money.
There is NO trajectory research required, no appointed panel, no fearless leader to fly around the world fact checking.....some bright folks who have the power to think....... :woot: :doh: :funny: :mad3: :alone:

I tried with Ben, no response. I've burned in the sons of b****es for over 43 years, over 2300 tons of PA Gold, If I didn't learn anything, hell I could be President!!! Hawaii is sure warmer than 03301!!!
Perhaps they need a new pet elephant WITH LARGER EARS, to hear the howls in the night........'like talking to wolves'......
whistlenut
 
Stoker Coal Boiler: AA130's,260's, AHS130&260's,EFM900,GJ&VanWert
Hand Fed Coal Boiler: Franks Boiler,Itasca415,NYer130,Van Wert
Hot Air Coal Stoker Furnace: Yellow Flame
Hot Air Coal Stoker Stove: Alaska-4,Keystoker-2,
Hand Fed Coal Stove: Alaska,Gibraltor,Keystone,Vc Vigilant 2
Hand Fed Coal Furnace: Van Wert, NYer's, Ford,Jensen.
Coal Size/Type: Rice,Buck,Pea,Nut&Stove
Other Heating: Oil HWBB

Re: Coalgun- Puff backs & Explosions

PostBy: lsayre On: Fri Dec 28, 2012 8:20 pm

I got a call from Darren at AHS today in response to my email sent yesterday. We discussed my idea that puff-backs occur for a brief period of time after loading large amounts of cold coal into the hopper, and that loading smaller loads of coal more frequently might be of benefit. I'm not sure I convinced Darren of anything here. Darren then instructed me to go to an SV of 100 degrees, which I did. I then told Darren about the NEPACrossroads forum, and invited him to check it out.

A few minutes ago I checked the S130 right after a fan cycle was completed and brightly glowing coals were quite evident in the draft port. This is what I remember for Blaschak last season, so it appears (for now at least) that setting the SV down to 100 degrees for Harmony coal is working.

Actually, since I had the 3 puffs yesterday there have been no more, so I'm convinced they occur right after loading it. If I get puff-backs again after loading the hopper with another round of about 160 lbs. of coal, I will switch to loading it more frequently with less fresh coal per load and see if that helps things. I went back to last years spreadsheet and realized that this is exactly what I was doing with the Blaschak. My loads were mostly in the range of 70-80 lbs. per charge last season, when I was keeping the hopper pretty full at all times.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Stockton Anthracite Pea
Other Heating: Resistance Boiler (13 KW)

Re: Coalgun- Puff backs & Explosions

PostBy: lsayre On: Fri Dec 28, 2012 8:27 pm

Freddy wrote:My AHS buddy Charlie found he had fewer puff backs if he kept the hopper near full and added a bag of coal each day, rather than add 5 or 6 bags once a week.


Freddy, I'm with you and your buddy on this one. I think he hit on something there!!!
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Stockton Anthracite Pea
Other Heating: Resistance Boiler (13 KW)

Re: Coalgun- Puff backs & Explosions

PostBy: Coalfire On: Fri Dec 28, 2012 9:58 pm

lsayre wrote:
Freddy wrote:My AHS buddy Charlie found he had fewer puff backs if he kept the hopper near full and added a bag of coal each day, rather than add 5 or 6 bags once a week.


Freddy, I'm with you and your buddy on this one. I think he hit on something there!!!



Well if this is so wouldn't that mean that the AA's are less likely to boom, but in freddys case it seems not.

As with the auger it only feeds a little coal at a time :idea:



Eric
Coalfire
 
Hand Fed Coal Stove: DS Machine 96K btu Circulator
Coal Size/Type: Nut

Re: Coalgun- Puff backs & Explosions

PostBy: lsayre On: Fri Dec 28, 2012 10:13 pm

Coalfire wrote:Well if this is so wouldn't that mean that the AA's are less likely to boom, but in freddys case it seems not.

As with the auger it only feeds a little coal at a time :idea:



Eric


They both feed only as much coal as they burn, so they both have to feed the same amount of coal for the same amount of burn time (for the same degree of ashing). The AA however does not have a load of cold coal sitting right on top of the fire tube.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Stockton Anthracite Pea
Other Heating: Resistance Boiler (13 KW)

Re: Coalgun- Puff backs & Explosions

PostBy: Coalfire On: Fri Dec 28, 2012 10:22 pm

lsayre wrote:
Coalfire wrote:Well if this is so wouldn't that mean that the AA's are less likely to boom, but in freddys case it seems not.

As with the auger it only feeds a little coal at a time :idea:



Eric


They both feed only as much coal as they burn, so they both have to feed the same amount of coal for the same amount of burn time (for the same degree of ashing). The AA however does not have a load of cold coal sitting right on top of the fire tube.



That is what I mean, if it is the amount of coal on top or being loaded at once you would think that the AA would never puff back.
Coalfire
 
Hand Fed Coal Stove: DS Machine 96K btu Circulator
Coal Size/Type: Nut

Re: Coalgun- Puff backs & Explosions

PostBy: macdabs On: Sat Dec 29, 2012 6:41 am

I fill my hopper almost every morning and the puff backs were at several different times of the day with the hopper at levels of 3/4 to full. The last major explosion was with a 3/4 hopper. Unless the hopper isn't sealing right I think the hopper level is not the problem.

Mac
macdabs
 
Stoker Coal Boiler: AHS 260
Coal Size/Type: Pea
Other Heating: Pellet,oil
Stove/Furnace Make: AHS
Stove/Furnace Model: S260

Re: Coalgun- Puff backs & Explosions

PostBy: Dennis On: Sat Dec 29, 2012 8:48 am

macdabs wrote:Unless the hopper isn't sealing right I think the hopper level is not the problem.
:idea: :?:
Dennis
 
Hand Fed Coal Boiler: AHS/WOC55-multi-fuel/wood,oil,coal
Coal Size/Type: Anthracite/stove size

Re: Coalgun- Puff backs & Explosions

PostBy: rwwsr On: Sat Dec 29, 2012 10:39 am

FWIW

If I were having puff backs (none to date that I know of on 3 260s) after lowering sv and/or hysteresis and adjusting port door to open as much as possible and still function properly. I would then look to slow down the ashing/feed rate.

Change sprocket size, replace gear motor or wire in a repeat cycle relay. Of the three options the relay would be the quickest and least expensive on a 260. Would be less than $90.00 and a less than 30 min install, while your at it you could add a $10.00 relay to keep unit from ashing unless fan was on if desired. The 2 relays should fit in the existing electrical enclosure if the 130 box is the same size as on a 260.

My logic is that it seams like the avg ashing cycle for my 260s put more coal on the fire and quicker than necessary. The avg cycle lasts about 15m+-, it takes about 5m+- to cover current fire with a layer of new coal (maybe more or less for a 130?) so I would start with 5m on 5m off and make changes from there to keep the new coal layer thinner.

All this assuming the puff backs are caused from build up and ignition of coal gasses. It’s a bit of a pia but this is what I would try for my next line of attack if all else failed to stop puff backs.

YMMV :)
rwwsr
 
Stoker Coal Boiler: ahs s260 3
Coal Size/Type: pea

Re: Coalgun- Puff backs & Explosions

PostBy: lsayre On: Sat Dec 29, 2012 11:17 am

rwwsr wrote:FWIW

If I were having puff backs (none to date that I know of on 3 260s) after lowering sv and/or hysteresis and adjusting port door to open as much as possible and still function properly. I would then look to slow down the ashing/feed rate.

Change sprocket size, replace gear motor or wire in a repeat cycle relay. Of the three options the relay would be the quickest and least expensive on a 260. Would be less than $90.00 and a less than 30 min install, while your at it you could add a $10.00 relay to keep unit from ashing unless fan was on if desired. The 2 relays should fit in the existing electrical enclosure if the 130 box is the same size as on a 260.

My logic is that it seams like the avg ashing cycle for my 260s put more coal on the fire and quicker than necessary. The avg cycle lasts about 15m+-, it takes about 5m+- to cover current fire with a layer of new coal (maybe more or less for a 130?) so I would start with 5m on 5m off and make changes from there to keep the new coal layer thinner.

All this assuming the puff backs are caused from build up and ignition of coal gasses. It’s a bit of a pia but this is what I would try for my next line of attack if all else failed to stop puff backs.

YMMV :)


This is some good advice. I have an unused repeat cycle timer.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Stockton Anthracite Pea
Other Heating: Resistance Boiler (13 KW)

Re: Coalgun- Puff backs & Explosions

PostBy: whistlenut On: Sat Dec 29, 2012 11:20 am

Larry, 2 every ten..........................
whistlenut
 
Stoker Coal Boiler: AA130's,260's, AHS130&260's,EFM900,GJ&VanWert
Hand Fed Coal Boiler: Franks Boiler,Itasca415,NYer130,Van Wert
Hot Air Coal Stoker Furnace: Yellow Flame
Hot Air Coal Stoker Stove: Alaska-4,Keystoker-2,
Hand Fed Coal Stove: Alaska,Gibraltor,Keystone,Vc Vigilant 2
Hand Fed Coal Furnace: Van Wert, NYer's, Ford,Jensen.
Coal Size/Type: Rice,Buck,Pea,Nut&Stove
Other Heating: Oil HWBB

Re: Coalgun- Puff backs & Explosions

PostBy: lsayre On: Sat Dec 29, 2012 11:27 am

whistlenut wrote:Larry, 2 every ten..........................


Mine is actually called a TORK EJWT "percentage timer". It has one dial for "percentage of on", and another dial for "time", with time ranging from 30 seconds to 24 hours, and percentage ranging from 0% to 100%, so I assume this would mean setting it to '20% on' and '10 minutes' of time. Does that sound right?

http://www.nsiindustries.com/Repository ... _SHEET.pdf

The wiring already restricts my ash grate motor from running unless the fan is on, and the Dwyer LC temperature control further restricts it so that it runs only when the ash grate temperature falls to 95 degrees, and it shuts off at 100 degrees and above. Would I circumvent the LC and go with having the ash grate motor run as a percentage of fan operating time instead?
Last edited by lsayre on Sat Dec 29, 2012 11:46 am, edited 1 time in total.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Stockton Anthracite Pea
Other Heating: Resistance Boiler (13 KW)

Re: Coalgun- Puff backs & Explosions

PostBy: whistlenut On: Sat Dec 29, 2012 11:46 am

I think that type of timer is on-off and repeatable. You need to be able to 'accumulate ten minutes of run time for the stoker motor, before you issue a command to run the ashing motor for 2 minutes. I will look over the specs in a few minutes, but you DO NOT want to have the stoker run 10 min, ash for two minutes all day. Only when the accumulated ten minutes occurs, then it runs for 2 minutes. The run time is KEY, because that will indicate the the appropriate ash has been created. It is not very scientific, but we are not t in the return trajectory planning stages.....only trying to safely burn black rocks to keep the family warm...and our workshops.....

You may be in luck, and trust me, all the rest is hocks-pocus. Combustion air needs a helping hand......purging itself. :idea: :idea: :idea: Fuel depth in the hopper is not the issue, as long as it does not run out.
whistlenut
 
Stoker Coal Boiler: AA130's,260's, AHS130&260's,EFM900,GJ&VanWert
Hand Fed Coal Boiler: Franks Boiler,Itasca415,NYer130,Van Wert
Hot Air Coal Stoker Furnace: Yellow Flame
Hot Air Coal Stoker Stove: Alaska-4,Keystoker-2,
Hand Fed Coal Stove: Alaska,Gibraltor,Keystone,Vc Vigilant 2
Hand Fed Coal Furnace: Van Wert, NYer's, Ford,Jensen.
Coal Size/Type: Rice,Buck,Pea,Nut&Stove
Other Heating: Oil HWBB

Re: Coalgun- Puff backs & Explosions

PostBy: lsayre On: Sat Dec 29, 2012 11:48 am

whistlenut wrote:I think that type of timer is on-off and repeatable. You need to be able to 'accumulate ten minutes of run time for the stoker motor, before you issue a command to run the ashing motor for 2 minutes. I will look over the specs in a few minutes, but you DO NOT want to have the stoker run 10 min, ash for two minutes all day. Only when the accumulated ten minutes occurs, then it runs for 2 minutes. The run time is KEY, because that will indicate the the appropriate ash has been created. It is not very scientific, but we are not t in the return trajectory planning stages.....only trying to safely burn black rocks to keep the family warm...and our workshops.....

You may be in luck, and trust me, all the rest is hocks-pocus. Combustion air needs a helping hand......purging itself. :idea: :idea: :idea: Fuel depth in the hopper is not the issue, as long as it does not run out.


Thanks Whistlenut! While you were typing this, I was adding more to my previous post, so please also go back and re-read it.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Stockton Anthracite Pea
Other Heating: Resistance Boiler (13 KW)

Re: Coalgun- Puff backs & Explosions

PostBy: Bob On: Sat Dec 29, 2012 11:58 am

lsayre

I have to wonder if your Dwyer LC control or the thermocouple are defective or there is a problem with the programming of the Dwyer control.

As to the programming issue--have you check all programming paramenters to insure it is set up for the intended function?
Is the control set for farenheit and not centigrade?

I don't really know how to test for a defective control or thermocouple but I think that would be a fair question to put to AHS.
Perhaps they could provide known good units for substitution.

Also--since the puff backs have resumed what are you observing about the fire height?

How long does the ashing cycle run typically? Any sense of how much ash is dumped in a typical cycle and does it vary widely?

Finally, I am unclear whether the suggestion is to replace the Dwyer control with the percentage timer, effectively making the unit like the AHS unit without the thermograte control, or the have the Dwyer control and the percentage timer working together is some way.
Bob
 
Stoker Coal Boiler: AHS 130
Coal Size/Type: Pea/Anthracite