By David Gecic
This is a story of how a Wide Screen TV met a burn-off oven and the fun they had that night.
The phone call came late. They always come late, often almost too late. I had just settled down in my comfy chair with a glass of bourbon, next to a crackling fire, with the latest book of poetry I had found. Then the phone rang.
“I need your help right now!”
It was a customer who had a burn-off or heat cleaning oven. The kind that has a second oven chamber built-in to process the exhaust. The kind normally used to burn-off paint or burn-out electric motors.
“I put a wide screen TV into my oven, I think it was about 4 by 6 feet, and now my temperature keeps climbing. It’s at 1100 now.”
“Ok, what else is in the oven?”
“Just two racks.”
“What kind of paint is on the racks.”
“They were covered by a heavy coating of grease and I wanted to get it off before I sandblasted it.”
I guess it was an unusual problem, but you don’t often run into usual problems. I was grateful that I did not sell this oven. I actually had not done much work on it. It was a typical burn-off oven, old, but still in good shape.
“Right now,” I said, “you’re putting out a whole bunch of black smoke and everybody for miles around can see it.”
He said: “Definitely, I turned off the afterburner.”
“Oh.”
“Yeah it went up to 2000 degrees. I didn’t want it to get any hotter so I shut it off.”
“Your water spray came on right?”
“Yeah I turned it on.”
“Turned it on?” I asked.
“Yeah, it isn’t working right, so I just turn it on and off manually. If it goes over temperature, I turn it on. It’s up to 1200 right now. What am I gonna do?”
So if the water-spray safety is “turned off” what other “adaptations” have been made? The water spray was supposed to keep the temperature down and the afterburner, which was now off, was not processing the smoke.
“What kind of nozzles are in there?”
“Those V-jet nozzles from my spray washer”
I quickly told him that that was a bad idea and explained why: the spray is supposed to starve the oven of oxygen. He said that the water was still on, but the oven wasn’t cooling down.
“It keeps on going up,” he screamed. “I gotta do something!”
I was going to tell him to run. I was going to tell him to call the fire department. I was going to tell him to call some other oven guy, but instead I told him to take a wet rag and put it over the blower for the bottom chamber, which he did. It cut off the air, and the temperature started to drop very quickly.
“Why a wide screen TV?” I asked (finally).
He said that the garbage men would charge him fifty bucks to get rid of it so, he decided to burn it.
AND then he said that he wanted to open the oven to see what it looked like. I yelled at him and he promised not to open the oven until tomorrow morning. I hope he did not. Personally, I really wanted to see what it looked like.
The last thing the customer said to me was:
“So you don’t think it would be a good idea for me to put the couch in there?”
There are a lot of lessons here. Probably too many to count.
First of all, if a customer calls in the middle of the night it is usually something a little strange, sometimes dangerous, and in this case both. A good vendor is someone who is available if there is an emergency and has the answers to solve any problem. If there is a problem with an oven, call someone. Day or night go to the person with the answers. Call me if you need help 312-550-7083.
I also learned not to put a TV into a burn-off oven. I myself have cooked several pizzas in a (new) burn-off oven to celebrate the installation and because I knew it was the last time the oven would be clean. I have known ovens to be used to dispose of cattle that had mad cow disease. I have seen people recycle the aluminum in oil filters by burning out their interior.
A TV is kinda a different thing. When you are burning off a motor there is a limited amount of resin inside. When you are burning paint off the surface of a metal you have a thin coating of organic material. There is actually not that much paint. Sometimes paint hooks have a thick layer of paint, but a big chunk of plastic gives off a lot of heat.
Every oven is designed to heat-clean a certain number of pounds of material per hour. The afterburners cannot process more than that effectively, and burning too much too quickly can lead to disaster.
The oxidizer or the afterburner processes the fumes that are coming out of the oven. If the oxidizer is turned off, then the pollution machine is turned on. If it is an emergency, there is a dilemma in terms of whether or not to turn the afterburner off, but, if possible, leave it on. The afterburner is also important for the air flow through the oven. But I guess if you don’t know what to do, turning it off is not a bad idea.
There are two types of water sprays that an oven can have. The first kind is integral to the way the oven operates and cannot function properly without it. The other uses the water spray as an emergency device to stop bad stuff from happening inside.
If the over-temperature suppression (OTS) system is not working – fix it. Fix it right; don’t cut corners. I say “system” because the nozzles, type of nozzles, size of nozzles and how long they spray are all important. I’ll write an article in the future about more details about water sprays.
I have used the wet towel trick before. The reason it works is because it blocks the air flow the burner from getting in the oven. It makes the fire inside suffocate itself. There are certain conditions where it will not work but it usually does.
Lastly – DO NOT open up an oven that is still hot and just had a fire or anything else that just happened inside. If it sounded or acted like there was a dragon inside wait a long time before you open that oven. In this case where the flame went out because the oxygen was gone, opening the door could actually cause an explosion.
This may be a fictional story. Please take it as so. Let’s say an oven parable. If anyone asks me I’ll deny I told it to you.
There are a dozen other lessons here but mostly – please no TV’s in ovens and please no couches.
Social tagging: Afterburner > Burn-off > Oxidizer > TV