Puffback blew pipe off of chimney and stove

Re: Puffback blew pipe off of chimney and stove

PostBy: gbru316 On: Tue Mar 14, 2017 3:35 pm

waldo lemieux wrote:Gee I dont know.... Looks like all the joints are screwed to me. The thing blew apart the 90. Ya cant fault anybody for that :gee: Too, with that much pipe into the chimney and it still blew out.... I dont think Id be ready to label the guy an idiot, and he did offer to come and fix it.



I can fault a professional for failing to realize that these adjustable elbows (this one still has the Lowes sticker on it) are susceptible to catastrophic failure given the right conditions - conditions that are much more likely with the equipment at-hand (and yes, I take full responsiblity for inducing these conditions). I see no reason why a fixed 90º can't be used here. Chimney pipe would not have blown out had the elbow not failed.

Also, only 2 screws were used per joint, and in each joint, 1 popped out.
gbru316
 
Hand Fed Coal Stove: Harman Mk III
Other Heating: Oil forced air


Re: Puffback blew pipe off of chimney and stove

PostBy: Lightning On: Tue Mar 14, 2017 5:59 pm

We should also suggest ways of preventing a puff back condition. In my experience the smaller sized coal (nut and pea) is more prone to puff back. The stove size is difficult to even force a puff back, but different setups have different results.

When I use small sized coal I'll crack the load door open about a quarter inch after loading until the blues are burning good. This keeps the volatile gases diluted until they can ignite safely over the fuel bed. Another method is keeping a corner of hot coals exposed. Others have said that boring a hole down thru the coal bed after loading works too.



With the stove size it seems I can just load and close it up without any problems.
Lightning
 
Hand Fed Coal Furnace: Overmodified/Bored out Clayton 1537
Coal Size/Type: Anthracite/Awesome Size

Re: Puffback blew pipe off of chimney and stove

PostBy: freetown fred On: Tue Mar 14, 2017 6:05 pm

I've probably had 2 lil puffs with my HITZER 50-93. I just open MPD for tending. Close up all doors SLOWLY when done topping off. Close MPD 1/2 way. Don't have to do anything else. That's with BLASCHAK nut. Course, I'm just into heatin my house, not having to constantly screw around with the old girl. Mine is not that much different from the MKlll
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut

Re: Puffback blew pipe off of chimney and stove

PostBy: oliver power On: Tue Mar 14, 2017 7:17 pm

freetown fred wrote:I've probably had 2 lil puffs with my HITZER 50-93. I just open MPD for tending. Close up all doors SLOWLY when done topping off. Close MPD 1/2 way. Don't have to do anything else. That's with BLASCHAK nut. Course, I'm just into heatin my house, not having to constantly screw around with the old girl. Mine is not that much different from the MKlll
Actually, it's the little things that do make them quite different Fred. Ya see, the Mark-III traps gas in the upper back part of the stove. If the gas is at full non-diluted strength, one little spark can create a BIG Ka BOOM. For this reason, the MARK series has no gasket at two sides of the glass. They call it an air wash, but it's really over fire air for diluting the gasses. Once gasses do ignite, the over fire air aids in burning the gasses.

The D.S. Circulator also pockets gas when the hopper is in. That's why sooo much over fire air in the D.S.. While experimenting / playing with the D.S., I closed up all my over fire air vents. I had a huge explosion. I never closed up all the over fire air vents after that. Now that I've pulled the hopper, it doesn't trap the gasses like before (another plus for pulling the hopper). Now the gasses travel around the baffle in full flow, and out. As long as all doors are closed, when gasses ignite, it's a soft, and gentle puff.

The HITZER doesn't trap gas like the MARK-III, or the D.S. Circulator. The gasses go around the hopper, in full flow, and out. Yes, it traps a little gas, but not like the MARK-III, or D.S. (With Hopper). That being said, any stove can have a KaBOOM if conditions are right. We all know that. However, the BIG Ka BOOMS are scary, and dangerous.

So, I'm curious to know if gbru316's MARK-III has the over fire air gap (missing gasket) at two sides of the glass. If not, maybe he should take some gasket out. :?: Lisa should be able to help here.
oliver power
 
Stoker Coal Boiler: KEYSTOKER Kaa-2
Hand Fed Coal Stove: Hitzer 50-93 & 30-95, Vigilant (pre-Vigilant-II), D.S. 1600 Circulator
Baseburners & Antiques: MANY (Mostly when burning wood)

Re: Puffback blew pipe off of chimney and stove

PostBy: rberq On: Tue Mar 14, 2017 7:30 pm

freetown fred wrote:Mine is not that much different from the MKlll
The stoves may be similar in size and BTU output, but the hopper alone makes your Hitzer very different from the MK III. Gradual continuous feeding of fresh coal from the hopper, vs. covering the whole burning mass with an equal mass of new coal. I have had FAR fewer puff backs of all sizes since switching from the MK I to the DS Machine, and then only when I got complacent and careless.
rberq
 
Hand Fed Coal Stove: DS Machine 1300 with hopper
Coal Size/Type: Blaschak Anthracite Nut
Other Heating: Oil hot water radiators, propane

Re: Puffback blew pipe off of chimney and stove

PostBy: gbru316 On: Tue Mar 14, 2017 7:55 pm

Lightning wrote:We should also suggest ways of preventing a puff back condition. In my experience the smaller sized coal (nut and pea) is more prone to puff back. The stove size is difficult to even force a puff back, but different setups have different results.

When I use small sized coal I'll crack the load door open about a quarter inch after loading until the blues are burning good. This keeps the volatile gases diluted until they can ignite safely over the fuel bed. Another method is keeping a corner of hot coals exposed. Others have said that boring a hole down thru the coal bed after loading works too.



With the stove size it seems I can just load and close it up without any problems.



Absolutely. I didn't do anything different this time than I did all last year, but it seems like the smaller particles really attenuated airflow -- much more than anticipated. I had, what I though to be, healthy flames rising from the bed before I added more, and I did not cover those flames. The combination of more coal and disrupting existing airflow by opening the door is what, I believe, led to the puffback.


Also, 2 pieces of glass are missing gasket at the bottom - intentional to provide over fire air, as mentioned. Sometimes, the gasses ignite right where this fresh air enters, and it looks like the glass is literally on fire.
gbru316
 
Hand Fed Coal Stove: Harman Mk III
Other Heating: Oil forced air

Re: Puffback blew pipe off of chimney and stove

PostBy: freetown fred On: Tue Mar 14, 2017 8:12 pm

OK--a lot different. :) I'm still thinkin the same tending procedure really helps on any stove. :|
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut

Re: Puffback blew pipe off of chimney and stove

PostBy: Lightning On: Tue Mar 14, 2017 8:21 pm

gbru316 wrote:Absolutely. I didn't do anything different this time than I did all last year, but it seems like the smaller particles really attenuated airflow -- much more than anticipated. I had, what I though to be, healthy flames rising from the bed before I added more, and I did not cover those flames. The combination of more coal and disrupting existing airflow by opening the door is what, I believe, led to the puffback.


Also, during these cold snaps it's easy to let the fuel bed burn down further than it usually does which results in loading more fresh coal at tending which leads to more volatile gas off the fresh coal. Add to that the burning hot stuff is buried even deeper.

Another variable could be chimney draft pressure. All of these things working together can lead to the right conditions for epic puff backs lol.
Lightning
 
Hand Fed Coal Furnace: Overmodified/Bored out Clayton 1537
Coal Size/Type: Anthracite/Awesome Size


Re: Puffback blew pipe off of chimney and stove

PostBy: CoalHeat On: Tue Mar 14, 2017 10:04 pm

Three screws in every connection.
I was worried the first time it happened to me!
Minor Explosion In Coal Stove
I also had my Mark I "blow up" a couple years ago when I was sitting right in front of it. Was great fun! :D
CoalHeat
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Baseburners & Antiques: Sears Signal Oak 15 & Andes Kitchen Range
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Puffback blew pipe off of chimney and stove

PostBy: coalkirk On: Tue Mar 14, 2017 10:05 pm

waldo lemieux wrote:Gee I dont know.... Looks like all the joints are screwed to me. The thing blew apart the 90. Ya cant fault anybody for that :gee: Too, with that much pipe into the chimney and it still blew out.... I dont think Id be ready to label the guy an idiot, and he did offer to come and fix it.


Waldo nailed it. You can see the screws in the photo. The elbow blew apart. Not the installers fault. It's nice of him to offer to come and help you and you should be thankful. You learned a valuable lesson about loading the stove. I would never use those adjustable elbows. Use T's or the corrugated elbows.
coalkirk
 
Stoker Coal Boiler: 1981 EFM DF520
Coal Size/Type: anthracite/rice coal

Re: Puffback blew pipe off of chimney and stove

PostBy: oliver power On: Tue Mar 14, 2017 10:07 pm

gbru316 wrote:Thanks guys, thats what I thought.

What about the flue collar/chimney adapter? Should that be secured to the wall? There are predrilled holes in the collar that look like they're supposed to be used for mounting hardware.
Every little bit helps. I have screws everywhere. Where the stove pipe enters the chimney, it's spring loaded. Also, a picture of stove showing no hopper.
Attachments
stove pipe 2.jpg
(105.58 KiB) Viewed 20 times
View: New PagePopup • Select:BBCode
[nepathumb]80055[/nepathumb]
stove no hopper.jpg
(104.83 KiB) Viewed 15 times
View: New PagePopup • Select:BBCode
[nepathumb]80056[/nepathumb]
oliver power
 
Stoker Coal Boiler: KEYSTOKER Kaa-2
Hand Fed Coal Stove: Hitzer 50-93 & 30-95, Vigilant (pre-Vigilant-II), D.S. 1600 Circulator
Baseburners & Antiques: MANY (Mostly when burning wood)

Re: Puffback blew pipe off of chimney and stove

PostBy: CoalHeat On: Tue Mar 14, 2017 10:10 pm

coalkirk wrote:
waldo lemieux wrote:Gee I dont know.... Looks like all the joints are screwed to me. The thing blew apart the 90. Ya cant fault anybody for that :gee: Too, with that much pipe into the chimney and it still blew out.... I dont think Id be ready to label the guy an idiot, and he did offer to come and fix it.


Waldo nailed it. You can see the screws in the photo. The elbow blew apart. Not the installers fault. It's nice of him to offer to come and help you and you should be thankful. You learned a valuable lesson about loading the stove. I would never use those adjustable elbows. Use T's or the corrugated elbows.


Agreed.
CoalHeat
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Baseburners & Antiques: Sears Signal Oak 15 & Andes Kitchen Range
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Puffback blew pipe off of chimney and stove

PostBy: gbru316 On: Tue Mar 14, 2017 10:23 pm

Not sure how you guys can say that adjustable elbows should be avoided, but then also say that it's not the installer's fault. No, the puffback isn't his fault. But using the adjustable elbows, is.

What likely happened is the force of ignition pushed against the chimney. High volume of expanding gasses put pressure back on the stove pipe. Stove pipe backed out of wall until the angle was great enough to push the adjustable elbow joint to failure. When this happened, everything fell down. Nonadjustable elbow = pipe still in wall, connected to chimney.

This is exactly the reason people pay professionals - to use their working knowledge to get the job done right. In this case, installer used the wrong product (according to consensus here) for the job. He replaced the entire stove pipe several months ago, and he chose the parts himself. Had the right product been used, I would have learned my lesson without having to evacuate my family from the house at 1 am in the middle of a snowstorm, and without damaged basement flooring.

The other lesson here is: if you want something done right, do it yourself. Which I usually live by, but these days between working full time out of state, raising a family, maintaining a home, and running a business on the weekends, I'm finding the time to learn how to do things right to be a bit lacking.
gbru316
 
Hand Fed Coal Stove: Harman Mk III
Other Heating: Oil forced air

Re: Puffback blew pipe off of chimney and stove

PostBy: coalkirk On: Tue Mar 14, 2017 10:34 pm

Don't want to start a beef here but the cause of this incident was the puff back. Adjustable elbows are used all the time. They are more common than the corrugated ones. I just said I wouldn't use them. They don't hold up as long as the corrugated ones. Again I'll say this was not the installers fault and you should be grateful he's coming to help you. Be grateful your error didn't result in personal injury or worse. We all screw up. This was just your turn.
coalkirk
 
Stoker Coal Boiler: 1981 EFM DF520
Coal Size/Type: anthracite/rice coal

Re: Puffback blew pipe off of chimney and stove

PostBy: gbru316 On: Tue Mar 14, 2017 10:52 pm

coalkirk wrote:Don't want to start a beef here but the cause of this incident was the puff back.


Totally agree.

I guess it's just a difference with how we view it. Root cause was absolutely my fault. Installer did not cause puffback. Period. He did, however, contribute to impact of said puffback by only securing pipe with 2 screws, not securing it to masonry wall, and using adjustable elbows.

And given by the number of "lol welcome to the big puff club, hahaha happened to me a few years ago" type responses, puffbacks are not uncommon with hand fired stoves. So, again, a professional should understand this and do what he can to ensure impact of a puffback is limited, or at least explained what options are available. Had he said "hey, I can install this adjustable elbow for $10 but I really recommend a fixed elbow or tee for $25 or $30 because of risk of pipe dislocation due to puffback -- which are more common with this type of stove," I'd absolutely have shelled out a few extra bucks for the parts the first time. When I hire someone, that's the kind of thing I expect. And when someone hires me for my side-business, that's the type of service I provide.

No hard feelings :)
gbru316
 
Hand Fed Coal Stove: Harman Mk III
Other Heating: Oil forced air