Puff backs in coal gun

 
Ttkrouse
Member
Posts: 23
Joined: Sun. Nov. 11, 2018 8:08 pm

Post by Ttkrouse » Sun. Nov. 11, 2018 8:26 pm

I read a post from several years back about a man named freddie could some how get his sight hole on the coal gun s130 to open 10 seconds before the blower shutoff to prevent puff backs how did you do this ?


 
User avatar
hotblast1357
Member
Posts: 5657
Joined: Mon. Mar. 10, 2014 10:06 pm
Location: Peasleeville NY
Stoker Coal Boiler: 1984 Eshland S260 coal gun
Coal Size/Type: Lehigh anthracite pea
Other Heating: air source heat pump, oil furnace

Post by hotblast1357 » Sun. Nov. 11, 2018 8:30 pm

Are you having puff backs?

If the fire is set properly there are no puff backs.

 
User avatar
StokerDon
Site Moderator
Posts: 7486
Joined: Mon. Nov. 11, 2013 11:17 am
Location: PA, Southern York County!
Stoker Coal Boiler: Gentleman Janitor GJ-5, Van Wert VA-600, Axeman Anderson130 X3.
Hand Fed Coal Furnace: Harman SF3500 reduced down to 3 grates connected to its own plenum
Coal Size/Type: Rice, Chestnut and whatever will fit through the door on the Harman
Other Heating: Noth'in but COAL! Well, Maybe a little tiny bit of wood

Post by StokerDon » Sun. Nov. 11, 2018 8:32 pm

Welcome to the forum.

This is the only "Freddy" that I know of on the forum. he has an Axeman Anderson though.
memberlist.php?mode=viewprofile&u=1789
You can send him a PM if you wish.

Getting the sight hole to pop open before the heat cycle ends probably isn't the way we would cure puff backs these days though.

Do you have one of the older Coal Guns that ash by a timer rather than ash temperature?

-Don

 
User avatar
hotblast1357
Member
Posts: 5657
Joined: Mon. Mar. 10, 2014 10:06 pm
Location: Peasleeville NY
Stoker Coal Boiler: 1984 Eshland S260 coal gun
Coal Size/Type: Lehigh anthracite pea
Other Heating: air source heat pump, oil furnace

Post by hotblast1357 » Sun. Nov. 11, 2018 8:39 pm

Like don is getting at, fire control is key.. the old way with a timer is no good...

Best way is to control ash is with a temp sensor, and ONLY ash when the fan is running.

I have not had one puff back. And I run a grossly oversized boiler that idles a lot, with 0 draft 90% of the time.

 
User avatar
coaledsweat
Site Moderator
Posts: 13763
Joined: Fri. Oct. 27, 2006 2:05 pm
Location: Guilford, Connecticut
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Post by coaledsweat » Sun. Nov. 11, 2018 8:44 pm

Stop ashing for a bit to raise the fire. Too much fresh coal on top.

 
Ttkrouse
Member
Posts: 23
Joined: Sun. Nov. 11, 2018 8:08 pm

Post by Ttkrouse » Sun. Nov. 11, 2018 9:53 pm

Mine ashes by temp set at 135 plenty of coal built up for fire bed seems to do it on long runs sight hole is open now placed a thin washer at bottom of flap to keep a small amount of air flowing in while blower is running has not popped again it cycled on and off about 6 times over a 6 hour or little longer period of time

 
User avatar
StokerDon
Site Moderator
Posts: 7486
Joined: Mon. Nov. 11, 2013 11:17 am
Location: PA, Southern York County!
Stoker Coal Boiler: Gentleman Janitor GJ-5, Van Wert VA-600, Axeman Anderson130 X3.
Hand Fed Coal Furnace: Harman SF3500 reduced down to 3 grates connected to its own plenum
Coal Size/Type: Rice, Chestnut and whatever will fit through the door on the Harman
Other Heating: Noth'in but COAL! Well, Maybe a little tiny bit of wood

Post by StokerDon » Sun. Nov. 11, 2018 10:01 pm

If it is Puffing back on a long run and not after shut down it may be ashing to much burying the fire. Lowering the ashing temperature may help and a little over fire air like you have added will help too.

-Don


 
Ttkrouse
Member
Posts: 23
Joined: Sun. Nov. 11, 2018 8:08 pm

Post by Ttkrouse » Sun. Nov. 11, 2018 10:11 pm

Yes it puffs back after a long run at shutdown. Making my wife very unhappy can't blame her. I leave the cap on the T above the hopper loose so it blows it off and doesn't blow the flu pipe apart. People from alternate heating are no help .

 
User avatar
coaledsweat
Site Moderator
Posts: 13763
Joined: Fri. Oct. 27, 2006 2:05 pm
Location: Guilford, Connecticut
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Post by coaledsweat » Sun. Nov. 11, 2018 10:53 pm

You should see a ring of fire breaking through the raw coal or about to at the surface along the wall of the firetube before it starts ashing.

 
Ttkrouse
Member
Posts: 23
Joined: Sun. Nov. 11, 2018 8:08 pm

Post by Ttkrouse » Sun. Nov. 11, 2018 11:18 pm

I can see small blue flames thru the sight hole . I thought that would burn off gas . Blower just kicked on and the asher ran a few minutes after that completed it's cycle and blower is still running . See if she pops ! I will try dropping the grate temp 5°see if that helps. It gets pretty frustrating after awhile . Funny no one from alternate heating seams no anything about puff backs . To bring the boiler backup to temp blower runs longer because of air coming in thru the flap and over the fire. She just ran for 20 minutes to bring boiler back to 175°. Blower runs when it goes down to 160°. Outside temp is 25°.no puff back .

 
User avatar
Freddy
Member
Posts: 7293
Joined: Fri. Apr. 11, 2008 2:54 pm
Location: Orrington, Maine
Stoker Coal Boiler: Axeman Anderson 130 (pea)
Coal Size/Type: Pea size, Superior, deep mined

Post by Freddy » Mon. Nov. 12, 2018 6:45 am

Hotblast gave you the most important key to this puzzle. You must change the wiring a bit so the asher can not run unless the fan is also running. I have a friend that has your exact boiler and that was the final thing for him. Since the re-wire he has had no puffbacks. One other thing he did which seemed to help some, is not FILL the hopper. He keeps enough in it for a day and a half or so, but always less than half full. We don't know if that really helped or not, but it seemed to so he continues that practice.

 
User avatar
hotblast1357
Member
Posts: 5657
Joined: Mon. Mar. 10, 2014 10:06 pm
Location: Peasleeville NY
Stoker Coal Boiler: 1984 Eshland S260 coal gun
Coal Size/Type: Lehigh anthracite pea
Other Heating: air source heat pump, oil furnace

Post by hotblast1357 » Mon. Nov. 12, 2018 6:47 am

Freddy, just for the record, I used to fill my hopper last year by hand, once a week usually, now with the auger it only keeps it about 1/2 full, I have seen no difference.

 
User avatar
Pa papa
Member
Posts: 96
Joined: Thu. Oct. 29, 2009 7:38 pm
Location: Summerville,PA
Stoker Coal Boiler: AHS-130
Coal Size/Type: Pea; anthracite
Other Heating: oil fired boiler; LP insert

Post by Pa papa » Mon. Nov. 12, 2018 8:22 am

coaledsweat wrote:
Sun. Nov. 11, 2018 8:44 pm
Stop ashing for a bit to raise the fire. Too much fresh coal on top.
That is the root cause. You correct that by slowing the ashing process either with addition of a couple of solid state timers and/or rewiring to ash only during time the I.D. fan is running.
I think you just got the wrong person at AHS. They have extensive knowledge of remedial actions for puff backs.
Tell the wife it can be eliminated, hang in there. :D
For now, you might try lowering the hysteresis down to 1 degree along with lowering the ashing temp.
Last edited by Pa papa on Mon. Nov. 12, 2018 9:19 am, edited 1 time in total.

 
User avatar
lsayre
Member
Posts: 21781
Joined: Wed. Nov. 23, 2005 9:17 pm
Location: Ohio
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Lehigh Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75

Post by lsayre » Mon. Nov. 12, 2018 8:50 am

Ask specifically for a technician named Darren Bricker at AHS. He knows his stuff!!!

But here is what I would do:
-------------------------------------------
Reduce your ashing temperature set-point to 110 degrees.
Reduce your ashing hysteresis set-point to 1 degrees.
Make sure it is wired so it can only ash while the fan is running.
Give it a few days for the changes to take root.

Does your AHS have an LC (Love Controls) brand PID that looks something like this one?
https://www.dwyer-inst.com/Product/Temperature/Pr ... /Series16B

 
User avatar
McGiever
Member
Posts: 10130
Joined: Sun. May. 02, 2010 11:26 pm
Location: Junction of PA-OH-WV
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Hand Fed Coal Boiler: BUCKET A DAY water heater
Hand Fed Coal Stove: Warm Morning 414A
Coal Size/Type: PEA,NUT,STOVE /ANTHRACITE
Other Heating: Ground Source Heat Pump and some Solar

Post by McGiever » Mon. Nov. 12, 2018 9:10 am

Remember AHS, in the end, had a kit to buy to correct sever cases of flawed limited production by a interim owner.
Long thread on puff back and flawed production caused some ruptured stove pipes many times over and over.


Post Reply

Return to “Stoker Coal Boilers Using Anthracite (Hydronic & Steam)”