Ovens with gas question

[getastro]

Hello there folks, have a quick question for anyone out there who is using gas for your ovens. I have successfully built a 4'x6'x4' oven running at 15k watts, but the electric bill runs a little high. I am going to switch to gas, I know about the safety valve and the solid state igniter. What I need is information on the burner, I am looking to run the oven around 250,000 BTU's per hour and not sure how big to build the burner. I thought that someone out there should have an idea how to figure out the correct size for the burner. I also thought about adding oxygen or compressed air into the mix to bring the heat up and cut down on fuel expense. Would this idea work alright for an oven. If anyone could help it would greatly be appreciated. Thanks

i use propane ... i got a double burner from a grill.... i have used a tordeo heat to i built the box hooked up air duct for the house heater and ran it in the box with air vents on the side to keep the neat to 425F ..... i am building a new oven with the help of 111111... but good luck

[11111111]

use electrical conduit, cheap and easy to bend up. make sure you drill all the burner holes in the very topp. i have put them in the sides and bottom and all this does is gets the pipe hot and eventually caues the tube to distorte and you gain nothing. so drill all the holes right in he top, remeber heat rises and if the burner is under the flame it can not get hot. go to the r.v. shop and buy an old propane oven or to the applaince shop and get a gas lp or ng stove and simply disassemble it and put t into your oven just like they have it installed. lengthen what needs to be lengthened. get your self a 3/8 or bigger plate to put over the burner for a shield so as not to expose the product to direct flame.
okay here is a trick i spent hours and weeks figuring out. where you run the gas line to the burner weld on to the conduit or thread on to it if you have away to thread it (does not matter) and connect the gas line. let the end of the burner run 8inches long before the first burner hole. install your gas fitting four inches from the first burner hole. now on the end of the burner, the other four inches out (same end as the gas is plumbed) install another fitting. by the way your running all the gas lines in the oven in copper tube, aluminum is a pain in the ass. now take this end fiting you just installed and plump it in copper flex tube to the outside and attach it to a 1/4 inch ball valve. on the other end of the ball valve i just screw in a fitting that my air compressor line will plug in too. this new gadget will do to things for you. 1 it will allow you to gat the maximum btu's out of you gas by feeding th air to the burner (just like a torch you now get control over the oxygen).2 it allows you to have a nice tight box with out the need for vents to feed air to the fire or to have your burner partiaolly on the outside so that it can draw in the air.
i just light the burner with all the stuff form the donor oven, use all the origanal stuff, if it is safe enough for yur kithchen with some care and understaing of what they are doing you should be just as safe in your work shop.
after you light the oven burner just look at the flame and start to crack open the ball valve and when the flame turns from orange to a blue just leave it thier and set your temp on your oven controls that you moved from your donor to the new unit.
i also use those long thermeter's that you use for deep frying turkeys, from the very bottom i drill a hole and install one right through the side of the oven and every foot up to the topp. you will be amzed at how this allows you to get a circulaton system installed that distributes even heat from topp to bottom, it works better than those temp guns after you use it a few times. yes you still need a fan.
a tip, drill the holes in your nw burner the same size and distance apart as the one in the oven you are using as the donor. just do this, i tried to re invent the whel here and nothing worked better. it takes alot of time and patience to build the burner so try to get it right the first time. trust me this is my most un favorite teedius part of the whole build. after you get done you will know what i mean.

[getastro]

Thanks for the info, but how safe is running gas over electric? The electric works, but heat slowly and runs the bill up. If I run the oven with gas at 250,000 BTU per hour thats around 3 gal per hour on LP. I am not of the price of LP at this time and if its cheaper than electric. Would gas heat up the parts in the oven quicker than electric would? Thanks for the help folks.

[11111111]

how big is the oven? how did you determine 250k btu? and are you using oven controls to regulate enternal temps? 3 gal of gas a hour is huge. it wont be anything even close to this. by the way gas is not always cheaper depending on how insulated the oven is. and for those with natural gas (ng) where i live it runs 0.15cents per gallon and propane is 1.69. how many hours in amonth are you burning the unit it should be like running a hot tub. jeff

i built mine like that but i use the box from the oven and monted it to a frame where the burners are at ...

[getastro]

The size of the oven runs 4' wide x 6' high x 4' deep. I looked around the net to find an professionally built oven that is close to same size and are running at 250K BTU's. I am running 12K on a electric at this moment. I'm looking for faster heat uptime and better part to heat saturation. As far as insulation concerned there is 3 1/2" on all sides. At the current moment I run an omega temperature control unit connected to a set of relays connected to heating elements. If I switched to gas I would go temperature control to relay to solid-state igniter to safety valve, which would connect to gas line. Unfortunately I do not have natural gas in the area. Propane is the only choice of gas available. I think the current moment by a oven is under powered, just looking to upgrade it. Thanks for the info.

call caswell and talk to lance he will be able to point in in the right way.. he helped me find some stock ...

[11111111]

your right you are way under on the heating system, sounds like plenty of insulation. we were just talking about the thought that your system would actually be more effiecient if you wre to install more elemnts or get higher rated ones. tht how it would work in a home. to small of a furnace runs a big heat bill and to large keeps it cheaper, but in a two large system you will get un even heating in a home but in your oven this is not aproblem. i think in you situation bigger may be a lot better. faster heat up and then much easir to maintan the temp. jeff

[getastro]

Thanks for the info. I wish I could add more elements, but I would max out the incomming power supply. I am running the oven on a 60 AMP breaker at this time and only have 100 AMP Main to my little shop. This is the reason thought about gas. Is 250K LP gas around the correct amount to run in this oven? If I run it with compressed air & gas mix this should cut down on the amount a gas used right?