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Biglou13

Forced air burner plans?

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Biglou13    202

At this point it's purely research/tinkering stage, but planning on building kiln in a year or so.. I like the idea/ principle of forced air burner. Any info or comments will be greatly appreciated.

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Marcia Selsor    1,301

Look up Bendel burners.named after Don Bendel from Flagstaff, AZ. I made a pair and used a squirrel cage blowers on each from Graingers. That was in 1971. I don't know if I could find the plans. I can try to draw it.

It was about a 12" 2" dia. steel pipe. A flange screwed on to the pipe and attached to a blower at one end and a bell reducer down to 1 or 1.5" at the other. Gas is introduced by intersecting 1/2 " black

pipe with tiny orifices drilled into it. I think I had 5 holes. You'd need to check what size orifices you need for the BTUs you need. the balk pipe is capped at one end on the outside of the 2" pipe and plumbed to LP on the other end. with a valve. I used a metal off a coffee can bolted to the air in take on the blower to adjust the air.

 

I fired a nice size catenary arch kiln with these to ^10. I had 4 100 gallon tanks of propane. I'd recommend a 500 gallon tank.

 

Marcia

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neilestrick    1,379

I posted some info about a simple burner system HERE. I recommend using, at the very least, a Baso valve and pilot on each burner. UV sensors would be ideal, but very expensive. Additionally, wiring up a high temp shutoff with electric solenoids on the gas lines is a good idea. Start budgeting, as safety is expensive.

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Marcia Selsor    1,301

I agree with Neil that the safety equipment is really good to have. I made these burners a long time ago and did not have safety equipment. It was out in the boonies, but it would have been a good idea.

Nice burner set up , Neil.

 

Marcia

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I posted some info about a simple burner system HERE. I recommend using, at the very least, a Baso valve and pilot on each burner. UV sensors would be ideal, but very expensive. Additionally, wiring up a high temp shutoff with electric solenoids on the gas lines is a good idea. Start budgeting, as safety is expensive.

 

 

High temp limit systems and UV sensors add complexity to a system that can be quite safe with simple vigilance--not saying they're not useful, but really their functions can be replicated by a use who is aware and understands how his or her kiln works.

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neilestrick    1,379

 

High temp limit systems and UV sensors add complexity to a system that can be quite safe with simple vigilance--not saying they're not useful, but really their functions can be replicated by a use who is aware and understands how his or her kiln works.

 

 

You need safety systems unless you can sit next to the kiln and watch it for the entire firing. No phone calls. No bathroom breaks. No lunch break. No emergencies. No heart attacks. Here's why: if the power goes out, the burners will be pumping pure gas into the kiln. It will immediately produce huge flames coming out of the kiln, possibly more than can be contained by the hood. I've seen it happen. Electric solenoids are needed to shut down the gas line if the power goes out. If a pilot goes out before the inside of the kiln reaches red heat, and the burner flame sputters out, you've then got raw unburned gas pumping into the kiln. Major explosion hazard. Again, I've seen it happen. Pilots burners are notorious for going out. Power burners do not run great at the very low pressures required at the beginning of a firing. Baso valves or UV sensors are necessary to shut down the gas if this happens. A high temp shutoff is necessary because, let's face it, life is unpredictable, and something may happen that prevents you from being there to shut off the kiln. Maybe you or a family member gets in an accident. Maybe you hurt yourself in the studio and have to go to the ER and forget about the kiln during the mayhem. It has happened to me.

 

Don't skimp on safety. Do it right. Spend an extra $1000 to make sure you and your home/studio are safe.

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Biglou13    202

Clarifying safety issues....

( I need the 101 version..... Rank beginner)

 

Flame creeps up gas line .......

Pilot goes out Kiln fills with gas....

Power goes out ...pilot goes out....

 

 

Once kiln is red hot the pilot issue goes,away? And since gas pressure Is higher after preliminary firing stages, less risk for flame creeping up? So there is more risk at prelim art stage of firing? $1000 of safety equipment might as well buy it built then its no longer worth DIY. :(/> :(/> :(/>

 

Marcia I researched burner no info....But I did get a good giggle because I know what a purple ditto is (aging myself). If u find the purple notes I'm still interested. If you find the notes and they still have that smell .....priceless

 

Pilot- with sensors and electronics to relight it self. basso valve- to shut off gas if pilot goes out. Peeper--shuts of gas if flame creeps up line. Does that cover the primary saftey systems? These parts that expensive?

 

If one is super vigilant with multiple people at kiln prepared to relight pilot, danger level,goes down...?? Danger levels goes down drastically when kiln is red hot?

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neilestrick    1,379

Power burners are more likely to go out at lower pressure, at the beginning of a firing. The pilot ensures the main burner stays lit so unburned gas doesn't fill the kiln. The Baso shuts down the main gas if the pilot goes out. Once the inside of the kiln is red/orange hot, the gas will burn and the burner will likely stay lit. Baso systems are manually lit, like on a water heater- hold the button, light the pilot. There are fancier spark ignition systems that will try to relight the pilot if it goes out. The Baso system is the simplest and least expensive.

 

If the power goes out, the blower turns off and the burner has no air in the mixture, causing a huge flame, probably outside the kiln. The electric solenoid will instantly shut down the main gas if the power goes out, as it requires power to stay open. This danger does not go down when the kiln is hot.

 

The high temp shutoff shots down everything- gas solenoids and blowers- if the kiln reaches its set point before you shut it off manually. This prevents over firing and ruining your pots or burning down your studio.

 

To buy a pair of burners with the Baso/solenoid system will cost you close to $2500 without a high temp shutoff, so it's a lot cheaper to build your own. Safety is not an area you should skimp, and you should not rely on people sitting there watching the kiln the whole time. Your burner system will last for years and years. It will pay for itself if you sell some pots.

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Marcia Selsor    1,301

Not an ideal solution, but when I was in cooled (4 decades + ago) my professor s suggested using chunks of soft insulation bricks placed in front of the burners as a safety measure. The bricks glowed orange quickly and they believed they could keep the flame from blowing out. As I said, not ideal.

I need to look at a Grainger catalog.

Marcia

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Biglou13    202

I'll draw something up this week and post it here for you.

 

Thanks. Dolomite......er... Neil the human tornado

 

While here anyone have any experience with forced air "wood burning"?

 

If I build a kiln with combination hard brick with fiber blanket, do I just use btu calculation for ceramic fiber?

 

Is there a problem if I go with a higher rated but out put burner....(building small at first, but optimistic...)

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Biglou13    202

Marcia Ty I'm in touch with Lowell via email.

 

I was given some burner parts. Forced air.

 

I will be slowly putting this together.

 

I need to get a estimate if btu out put so I an build kiln from there.

 

Its a home made job. I recall reading how to calculate btu output by measuring gas orifice size? Can't find post. Can anyone help here.?

 

I was given 2 blowers with burners, pilot system ( not electronic). Ill post pics i soon (finishing up,for first show) wide photo some parts in "another kiln build" thread...

 

Does any have plans for DIY Venturi burner? Or one they aren't using? Back up, alternative source.

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Marcia Selsor    1,301

usually a gas company will have a chart for the orifice size and btu output. Many gases vary by location.

Contact your gas supplier.

Marcia

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Biglou13    202

Plugged in one of the squirrell cage blowers. At max on dial. Was no where near 100cfm which I've read they are rated at. Ok I really don't know what 100 cfm feels like. But I do have a small room fan that is rated at 150 cfm. The blower wasn't even in ball park. Not familiar at all with these but as they age they loose ability to move air? Any way to test cfm? What cfm is necessary for forced air burner? ( I recall a post about this if I find ill post link)

 

I researching alternative sources. Ill post when I have more ino

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Marcia Selsor    1,301

100 cubic feet per minute one a 3 x 3" fan may be sufficient relative to a 24" x 24' 150 cfm window fan.

If you have a propane torch, light it and hold it in front of the blower and see what happens. You are trying to introduce air to the flame of natural gas. You don't want to blow it out.

 

Marcia

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Biglou13    202

I went and played with it after posting. There was Missing bolt from blower to pipe, taped up gas orifice hole up, and got much better output... Then I realized..... Duh..... Dimmer dial........chances are i won't need 100cfm........ Especially. For smallish kiln.

( note to self don't test stuff when tired and late at night) ( so for most part disregard, in my best Gilda Radner voice......"never mind!"

 

Next question

 

What temperature do I need killn for gas to self ignite? What temp is red hot? ( yeah I'm trying figure options, before I drop coin for basso, and or other saftey parts)

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Marcia Selsor    1,301

I think red heat is when a kiln would ignite. ..but if the blower is running it may not ignite. I have used a round section of metal screwed over the air intake for reducing the air.

 

Get the basso before you invest in a dimmer. It is more expensive but well worth it.

Glad the blower is good.

 

Marcia

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I went and played with it after posting. There was Missing bolt from blower to pipe, taped up gas orifice hole up, and got much better output... Then I realized..... Duh..... Dimmer dial........chances are i won't need 100cfm........ Especially. For smallish kiln.

( note to self don't test stuff when tired and late at night) ( so for most part disregard, in my best Gilda Radner voice......"never mind!"

 

Next question

 

What temperature do I need killn for gas to self ignite? What temp is red hot? ( yeah I'm trying figure options, before I drop coin for basso, and or other saftey parts)

 

 

Don't "invest" in a "dimmer" switch--unless its rated to be used with a load like your blower will produce, you'll burn out a lamp dimmer switch quickly. See how your blower has an intake on the side? Use a flat fridge magnet to cover that, you can adjust how much of the intake is covered to adjust your air output to the burner--simpler and cheaper than a rheostat for the blower. Now take that money you saved, go drop the ~125.00 on a baso valve.

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Biglou13    202

I think red heat is when a kiln would ignite. ..but if the blower is running it may not ignite. I have used a round section of metal screwed over the air intake for reducing the air.

 

Get the basso before you invest in a dimmer. It is more expensive but well worth it.

Glad the blower is good.

 

Marcia

 

It came with rheostat/dimmer. I trying to figure out how to put together basso. I need hose and fitting,plumbing lesson.

 

Also found a few different basso devices on Internet, which one do I need?

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I think red heat is when a kiln would ignite. ..but if the blower is running it may not ignite. I have used a round section of metal screwed over the air intake for reducing the air.

 

Get the basso before you invest in a dimmer. It is more expensive but well worth it.

Glad the blower is good.

 

Marcia

 

It came with rheostat/dimmer. I trying to figure out how to put together basso. I need hose and fitting,plumbing lesson.

 

Also found a few different basso devices on Internet, which one do I need?

 

 

depends on a few things, one of which being the pressure that is feeding your burner(s). More information here: http://www.wardburner.com/burnersparts/safetyvalvesthermocouples.html

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Biglou13    202

I think red heat is when a kiln would ignite. ..but if the blower is running it may not ignite. I have used a round section of metal screwed over the air intake for reducing the air.

 

Get the basso before you invest in a dimmer. It is more expensive but well worth it.

Glad the blower is good.

 

Marcia

 

It came with rheostat/dimmer. I trying to figure out how to put together basso. I need hose and fitting,plumbing lesson.

 

Also found a few different basso devices on Internet, which one do I need?

 

 

depends on a few things, one of which being the pressure that is feeding your burner(s). More information here: http://www.wardburner.com/burnersparts/safetyvalvesthermocouples.html

 

 

I don't know yet. I do know its from propane tank. Size TBD. I've been studying lots of info from ward, grainger, basso, http://gashosesandregulators.com, Neil "dolomite" posts.

 

What information is necessary in determining pressure?

 

Sorry for all the questions. The gas stuff is like a foreign language. I'm stepping into unknown territory. I feel like 1st grader I'm trying to teach my self calculus.

 

I'll post images of components given to me soon.

 

And thanks for the help.

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neilestrick    1,379

First you need to determine how many BTU's/Hr you'll need for the size and materials of your kiln. Then look at an orifice size chart. The size of the burner orifice will be determined by the type of gas (propane or natural) and pressure available. You have to make sure the pipe size and pressure combination can deliver enough BTU's.

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