Vented burner no-no

[Chappy 138]

vented my burner as in the pic below. http://www.thegrimescene.com/forums/attachment.php?attachmentid=2556&d=1125682610 The problem was it caused back pressure and burned the ignitor out. Was told by the mechanic to leave a space between bottom of vent and top of burner, so as to create a venturi effect. also to only use straight pipe.

Other problems caused were a severe build up of soot and (because of another problem, a build up of unburned deisel.)

the stuff is still burning off after 4-5 uses. made a great show at night with the flames.

.Anyway, moral of story, vent carefully.

[Don Phelps 85]

Yep, I've seen that same machine smoke before.

[Russ Johnson 141]

The reason that happens is because the fan in the burner is there to mix enough air with the fuel for a clean burn. It is not designed to push a column of air up a pipe. I like one of those reducers, say from 12" to 10" or even 8", sitting just an inch or two over the stack. As the pipe warms, it will draw air up inside by itself.

Is the smoke flowing out the stack well, or does it kind of roll over the edge. If it's only rolling out, you may need to pull the burner head and manually wash the coil. The soot may be so built up that the burner just plain can't breathe.

[John T 744]

I'm just about done with my dream rig and I have pipes bending also. I'm keeping my fingers crossed. My Burners are going to run on Propane which is much cleaner then diesel so I'm hoping I don't get this problem. I'll post pictures when I get a chance down the road.

[Ron Musgraves 240]

John, your pipe is solid? You shoulnt have this problem then. even if the fuel mixture goes bad.

[Russ Johnson 141]

I'm just about done with my dream rig and I have pipes bending also. I'm keeping my fingers crossed. My Burners are going to run on Propane which is much cleaner then diesel so I'm hoping I don't get this problem. I'll post pictures when I get a chance down the road.

You REALLY ought to start your stack with a draft diverter on the machine to draw air up and out of the combustion chamber for a clean burn and to evacuate exhaust. A gas burner will soot up without the right fuel / air ratio. Gas burners have no fan at all, so even the air flow that an oil burner has isn't there. Also, John, remember this - LP gas is heavier than air...if the burner doen't light properly, you could be standing in a fire ball.

[John T 744]

You REALLY ought to start your stack with a draft diverter on the machine to draw air up and out of the combustion chamber for a clean burn and to evacuate exhaust. A gas burner will soot up without the right fuel / air ratio. Gas burners have no fan at all, so even the air flow that an oil burner has isn't there. Also, John, remember this - LP gas is heavier than air...if the burner doen't light properly, you could be standing in a fire ball.

Russ do you have any pictures of what this draft diverter looks like and where can I purchase one--------------Thanks

[Russ Johnson 141]

This came out huge..but the gist is - as the hot combustion air heats the pipe, cooler air wants to rush in around the outside. As the cool air rushes past, it creates a venturi to draw air up past the gas burner ring, through the coil, and out through the stack. They usually stand 12" - 18" high, so space may be a problem for you. They are available in 8", 10", and 12" diameters.

[Chappy 138]

I did cut out the grill to get better flow, but I think im just going to leave it openand not vent it. the position at the rear of my trailer is such that I only have a little soot on the back corner of the ceiling. With the side door open, there is enough air going through so that I can get inside for a few minutes with out asphixiating. and its not usially burning when im inside the trailer a. anyway .

Don, I hope this is the last of the problems. Other than burner problems and a starter switch, Ive been real happy with this machine.

[John T 744]

Russ,

Thanks for the info. I have two more questions. 1- Where do you buy this and 2-Why is it that you can just use exhaust pipes to vent out an engine and you don't need a draft diverder or is that what the muffler does??

[Ron Musgraves 240]

Russ,

You show the draft diverter outside? I like that, The others i saw where not. Is that correct?

[Russ Johnson 141]

An internal combustion engine creates pressure, much like an air compressor. It needs no help to vent. I can get a 10" from Hydro Tek for $100.00.

No, Ron, the diverter sits right on top of the coil chamber. Lousy artist...lol

[Aplus 525]

I'm thinking a draft diverter could be purchased from a supplier who carries the galvanized piping. Maybe even HD or Lowes.

Thanks for pointing that out Russ, I'm going to add a diverter to my setup as well.

[Ernie Greese 14]

Russ,

your reply to John T

draft diverter on the machine to draw air up and out of the combustion chamber for a clean burn and to evacuate exhaust. A gas burner will soot up without the right fuel / air ratio. Gas burners have no fan at all

John T will be using LP gas, do you recommend draft diverters for oil fired burners also. John C who asked the original ? has what appears to be a diesel/oil fired burner. Are you speaking of the diverters on top of gas fired home water heaters?

[Russ Johnson 141]

On oil fired burners, just suspend a 12 -8 reducer over the stack 1 or 2 inches. A draft diverter would work the same way. Biggest difference on a diverter is, as the name implies, there's a plate of metal in the thing that "diverts" downdrafts, should they occur, to keep the fire stable.

Yeah, Ernie, gas water heaters have little bitty ones.