Brick Oven (Gas fired)

[Aldream]

Re: Brick Oven (Gas fired)

A good book on kiln set-up as far as gas: THE KILN BOOK by Frederick L. Olsen. He gives a good breakdown on how to install and test a gas firing system. Gas can kill you in a number of ways so it is best to read up on it before you run a open pipe into your house.

Thank you for advice. I will try to get hold of this book.

[Aldream]

Re: Brick Oven (Gas fired)

dmun: although I realize the risk of using gas; but almost every restaurant around here have a similar oven as mine with the same setup. I wish I could find standard burners that would fit in my oven, but I doubt I can find one because of the length.

You mentioned that zinc and heat is not good; in what way?

[RTflorida]

Re: Brick Oven (Gas fired)

When heated, zinc "gases" - creating a toxic vapor. Do a google search of "metal fume fever" and you will find plenty of info on the effects. Welders and any foundry workers are well aware that galvanized steel and high heat don't mix. Damaging effects are not just long term......meaning, the right concentration of this vapor in an enclosed space (your home) could prove fatal from merely 1 exposure (heating your oven for pizza).

I hate to sound like the grim reaper.....but damn, this is your home. Just not worth the risk.

RT

[jmhepworth]

Re: Brick Oven (Gas fired)

I look at your fire, and it's pretty inconsequential compared to a wood fire heating up an oven. I suppose it would just take longer, particularly because there is no fire on the floor, the floor needs to absorb heat from the roof. Do you know what insulation is under the floor?

[Tscarborough]

Re: Brick Oven (Gas fired)

That is why gas work is done with black iron. Zinc and heat=big time no-no.

[nissanneill]

Re: Brick Oven (Gas fired)

Hi Aldream,
your pictures tell the true story. Your fire is like putting a series of candles in the oven to heat it. The flames should be much bluer and 3 to 4 times the height.
I am assuming that your LPG cylinder is coupled to your jets through a pressure regulator - yes?
Well, let me tell you a story of a close friend who had a powder coating business and heated his oven with electric elements which proved too slow, only 2 firings per day, so he contracted a gas installation with a jet of natural gas squirting into a 8" diameter black steel pipe that went across the back 8ft of the oven and then 20 ft down the length and then 4 ft up towards the top of the oven. The pressure in the gas input line was 2 lbs/sq. inch (which is only permitted with a permit into commercial and industrial applications over here), when compared to a household pressure of only around 1/2 to 3/4 lbs/sq inch. However, the increased pressure would shoot a flame almost 20 odd feet through the pipe heating it to a glowing red hot in around 5 minutes.
I think that you need to contact a specialist who can professionally advise you an the proper and safe installation, but I feel that with lpg, you will not need a regulator.

Neill

[Aldream]

Re: Brick Oven (Gas fired)

That is true... the gas tank is coupled to pressure regulator, but I have set on the max. I played around witht he air/gas mixer; however, that is the best setting I was able to acheive. Unfortunately, I am not able to find a specialist around here.

I called the gas company and requested a regulator that has a higher pressure rating but they advised me that with the size of tank I have gas might freeze if I utilize a higher pressure regulator!

I think the first thing I will do is to replace the burners with normal CS ones.

[Aldream]

Re: Brick Oven (Gas fired)

For all those who asked about the insulation and bricks used in the oven, I called the guy who made it for me and he told me that the bricks are fire bricks (except the ones used on front door). As for the insulation, he told me that he used salt as an insulator under the floor bricks and on top of the dome. I remember he dumped many salt bags over the oven after building it.

[Aldream]

Re: Brick Oven (Gas fired)

oh, one more thing: he told me that I can increase the temperature of the oven floor by wiping it with a wet peice of cloth once in a while while the oven is heating up.

[Aldream]

Re: Brick Oven (Gas fired)

Aldream

Can't give you any advice the gas topic, but would like to compliment you on the brickwork in your pizza-oven. Very nice job, but they don't look like fire-bricks to me. What type of brick are they? Also nobody has asked you what type of insulation is under the hearth. If the hearth itself is'nt made from a heat retaining brick and their is no insulating layer between your slab and the hearth then this might cause you problems. There probably is, and I'm just summising.

Interesting thread. Shall keep tuned in and I hope you find a solution to your problem.

Terry (C.F)

Thank you for the compliment. The guy who built it for me did a good job. I will try to take more pictures of the oven from the outside and also the chimney and post them here. I had also a fire place built from these bricks which I will try to also post here.

[cannyfradock]

Re: Brick Oven (Gas fired)

Aldream

I built my wood-oven by masonry experience and guesstimation. I came across this forum AFTER my build and I'm sure that if I described exactly how my oven was built, I would have recieved a lot of constructive criticism. I believe that is what you have recieved in the latest posts to your thread. After following this forum for a while I realise that the people of knowledge on this forum are only voicing their genuine concerns, and giving you the benifit of their experience

Keep battling on with your original concerns about your wood-oven and USE the comments voiced to find a solution.

Best of luck

Terry (C.F)

[Aldream]

Re: Brick Oven (Gas fired)

Aldream

I built my wood-oven by masonry experience and guesstimation. I came across this forum AFTER my build and I'm sure that if I described exactly how my oven was built, I would have recieved a lot of constructive criticism. I believe that is what you have recieved in the latest posts to your thread. After following this forum for a while I realise that the people of knowledge on this forum are only voicing their genuine concerns, and giving you the benifit of their experience

Keep battling on with your original concerns about your wood-oven and USE the comments voiced to find a solution.

Best of luck

Terry (C.F)

I do very much appreciate all the criticism I am receiving in this forum. I am learning and hoping that someone else will learn from my experience.

[lwalper]

Re: Brick Oven (Gas fired)

And, before we build a bigger fire is the flue adequate?

As far as running small LP tanks without a regulator it can be done and you can squirt a HUGE flame out the burner—but the tank will chill and gas flow will diminish to something that is probably less than adequate for heating all this masonry. I have a 450,000 BTU weed burner attached to a 30# unregulated cylinder that will put out a flame-and-a-half—it's impressive!! But after a few minutes of wide-open burning the tank does develop frost on the outside and fuel pressure/flow drops, limiting the flame size and heat output.

[Aldream]

Re: Brick Oven (Gas fired)

And, before we build a bigger fire is the flue adequate?

As far as running small LP tanks without a regulator it can be done and you can squirt a HUGE flame out the burner?but the tank will chill and gas flow will diminish to something that is probably less than adequate for heating all this masonry. I have a 450,000 BTU weed burner attached to a 30# unregulated cylinder that will put out a flame-and-a-half?it's impressive!! But after a few minutes of wide-open burning the tank does develop frost on the outside and fuel pressure/flow drops, limiting the flame size and heat output.

I think I have got a problem with my burners. The flame they shoot is mostly yellow in colour. If I increase the air opening, the flame starts getting bluer but it gets shorter and blows away from the burner. I am now doing some reading on burners and hopefully I will know why I have this problem. Although I have already decided to change the burners since they are galvanized steel as recommended by dmun earlier in this thread, but I want to make sure that I have the right design before doing that.

[lwalper]

Re: Brick Oven (Gas fired)

Yep, those are HUGE holes in the pipe. At low pressures and gas flows that's great, but when the flow increases you will blow more gas and blow it faster than the flame front can travel. There's a particular velocity that gases in various air/fuel mixtures like to burn. You're blowing pure fuel out those holes and snuffing out the flame with excess fuel (more than it can burn at the time). What you've got there is a good setup for a fireplace, but not so good for what you're trying to accomplish.

Check these Raku venturi burners: Ward Burner Systems - Power Burners, Raku Burners, and Kilns

They'll put some heat in your oven!

You might also look at getting a tank with a horizontal configuration which will give more surface area for the gas to change from a liquid to a vapor in the tank—or, tilt the existing tank about 15-20 degrees - that will accomplish the same thing. Just beware that when you tilt the tank there is always the possibility of squirting LIQUID fuel out the burner nozzle which makes a REALLY BIG and probably unexpected flame (read: DANGEROUS!!)