Commercial Pita Bread Oven Remodel

[seesoe]

i just realized that the server wasn't allowing the pictures from being shown, but i fixed it now, you may find the images here at this link

also i placed an order for a digital multimeter and a 10 inch high temperature k thermocouple. im going to start logging some temperatures, i should have some numbers posted by the weekend.

open for any questions comments or concerns
thanks
cheers
seesoe

[nissanneill]

Hi Seesoe,

i found out the bottom burners have a metal plate on top of the flame not to burn the bread, however the top burners do not, they need it though, when the bread over poofs and is baked then it gets burned because the flame is so close to it.

I built a conveyor drier which incorporated both Ultra violet and/or Infra red radiation to dry/cure screen prints. The infra red lamps were so hot (even though I had it thermostatically controlled, it would burn and destroy the textiles being cured. To overcome this, I put some expanded metal (I used aluminium but you might need to use some stainless steel due to the higher temperatures and melting points) directly beneath the lamps. Problem solved.
The perforations in the metal will still allow the heat to radiate to the breads but the flames will be prevented or severely limited.

Cheers.

Neill

[seesoe]

yeah it is a pretty important feature to have in ovens, the bottom has it as you can see here, i was thinking i could just put a strip of stainless down the length of the burners, and simply mount it to the beams holding the burners, you can see what i mean in here and here

cheers
thanks
seesoe

[drogers]

seesoe,
I had a chance to review your photos. Next time I am up in Gainsville I will give you a call. These are some of the observations and questions I came up with.

1. Could you just box in the return conveyor section and put some insulation over the box, as opposed to relocating the conveyor up into the existing oven area below the bottom burners ? A fabrication shop should be able to bend what you need out of light gauge mild steel at a minimum cost.

2. Can the discharge opening height be reduced without hitting the bread being discharged? This could be a major heat loss.

3. Is the distance between the conveyor deck, that the bread rides on, and the bottom of the top heater pipes sufficient to place a 3"x3" angle under each pipe ? The angle would be mounted like the letter "V" and would hang down about 2 1/4" from the cross supports that the pipe rests on. This would prevent directly "broiling" the bread, but still allow good heat circulation. The width across the "V" would be about 4 1/4", so you may be able to go with a different size angle. I thought of angle because it would be more self supporting.

4. Does the flue have any kind of manual or automatic damper ? If not, and if code allows, that could yield substantial savings. Without a damper you are discharging your heat almost as fast as it is being generated. These automatic units are also called barometric control dampers and are purely mechanical .

5. Could you install a larger propane tank? The larger the tank the less you and the dealer have in delivery charges. Delivery charges may not be listed seperately, but the are incorporated into what you are paying for propane. If you install a larger tank, and retain ownership of the tank then you can put your propane requirements out for bid. If you do not retain ownership then you cannot get competitive bids.

6. Does the cooling conveyor area after the oven cause a draft back into the oven because of the fans? Could this area be shrouded from the discharge of the oven ?

I hope some of these thoughts help you .
Don

[seesoe]

Originally Posted by drogers

I had a chance to review your photos. Next time I am up in Gainsville I will give you a call. These are some of the observations and questions I came up with.

thank you for your time. that would be great.

Originally Posted by drogers

1. Could you just box in the return conveyor section and put some insulation over the box, as opposed to relocating the conveyor up into the existing oven area below the bottom burners ? A fabrication shop should be able to bend what you need out of light gauge mild steel at a minimum cost.

yeah, this is what i am planning on doing, however i didn't mean to say relocate the belt in the oven but to higher the belt rollers a few inches up so the belt wont sag as much and move the ovens sheet metal floor to under the belt, this way the return belt will always remain isolated in the main body of heat of the oven, you can see what i mean in here and here

Originally Posted by drogers

2. Can the discharge opening height be reduced without hitting the bread being discharged? This could be a major heat loss.

we have little flaps that we can lower a bit more, but i am going to get rid of them and put something more efficient and have it continue down the edges of the discharge area, you are right it is pretty open, a good couple of inches on either side just wasted open, as shown here

Originally Posted by drogers

3. Is the distance between the conveyor deck, that the bread rides on, and the bottom of the top heater pipes sufficient to place a 3"x3" angle under each pipe ? The angle would be mounted like the letter "V" and would hang down about 2 1/4" from the cross supports that the pipe rests on. This would prevent directly "broiling" the bread, but still allow good heat circulation. The width across the "V" would be about 4 1/4", so you may be able to go with a different size angle. I thought of angle because it would be more self supporting.

that is a good idea i would have to take some measurements and report back, the heat of the angle iron can act as a nice heat source to make the bread have a nice color on top

Originally Posted by drogers

4. Does the flue have any kind of manual or automatic damper ? If not, and if code allows, that could yield substantial savings. Without a damper you are discharging your heat almost as fast as it is being generated. These automatic units are also called barometric control dampers and are purely mechanical .

no it is just a straight opening through the flue, i have thought about it though, later on when i get the oven nice and isolated to sustain heat, i am thinking about installing a PID system, like an oven controller, and i was thinking of putting a fan in the flue for the controller to control. the barometric dampers look interesting though i would have to get in contact with the city about it. ill see if i have some time to talk with them.

Originally Posted by drogers

5. Could you install a larger propane tank? The larger the tank the less you and the dealer have in delivery charges. Delivery charges may not be listed seperately, but the are incorporated into what you are paying for propane. If you install a larger tank, and retain ownership of the tank then you can put your propane requirements out for bid. If you do not retain ownership then you cannot get competitive bids.

this is also a thought, the 100 gallon tank we have is leased but they only fill it to 80 percent every week they come out, and we use about half of that a week

Originally Posted by drogers

6. Does the cooling conveyor area after the oven cause a draft back into the oven because of the fans? Could this area be shrouded from the discharge of the oven ?

not that i know of, i made sure to position the fans and an angle away from the oven like this "/"

thank you for the help, ill get back with more info as i get it.

cheers
seesoe