Any one doing high heat applications?

Getting ready to start building a pellet fired glass melting furnace. (Free standing crucible 190 lbs) The several glass furnaces I've done before were propane or natural gas. This burner so far was going to be modeled after a chip burner. Plans are for an adjustable tilt and refractory air hole modules that can be swapped out to try different styles. While buying pellets for our sweet home pellet stove the dealer mentioned wood pellet pulverization and blowing the dust as a high heat method. So my plans are less firm.

Heat exchangers have always played an integral part of my chimneys. Saving an honest 25% on six to nine hundred gallons of propane a month is a big deal.

Exhausting the flue gas through the (refractory) floor of the combuster unit will knock the edge off the up to 2600F corrosive exhaust. Exhaust further exchange takes place around a jacketed Inconel tube.
Glassblowing is the Electric Guitar of the art world... Check it out!!

Any one with any ideas notions or suggestions are welcome. One concern is too short a flame. Another issue is how to introduce secondary air.

Thanks
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Kraig

BrownianHeatingTech said:

Interesting application.

I'd probably design around chips, rather than pellets. Dry chipwood is a lot cheaper than pellets, and it sounds like you'll be using a lot.

One issue may be the cleanliness of the flame, in any solid-fuel application. The only demonstrations I've seen used exposed flame, but I must admit that I may be ignorant of the breadth of glassblowing technology, and perhaps you have a system which does not expose the glass to the flame?

Joe

Click to expand...

Thanks for responding Joe...

I like chips and have only really studied chip burners as the pellet units are all smaller.... low BTU ....low temperature. One problem with wood chips here-abouts was a few years ago, Shelburne Farms called up for their chips and was told that they just missed them ...that the chips had gone to McNeil ( A mega wood chip electrical generation plant in Burlington) A few more calls and no chips. Shelburne Farms is a huge multi faceted operation with many activities that couldn't afford to be left out in the cold. Conversion to pellet was soon underway. Chips are stringy prone to hang up, and need more horsepower to move. But they are a lot cheaper then pellets. Depending on efficiencies Nat Gas at 1.61$ a therm, is not that far from pellets at 300 a ton. Nat Gas from Quebec is coming down 7% in January. They are putting in a line on our street. It is only 1500 feet of ledge to get down our driveway. So close but so far. As a bona-fide tree hugger I'd still commit to this pellet furnace even if I had access to the Natural Gas supply.

My previous furnaces have often employed flame impingement where the burner is aimed and focused at a full tank level to help melt faster ( A trend picked up by float glass manufacturers over the past few years.) With the wood fired glass the flame will be below the lip of the crucible and a refractory ring on the furnace combined with downdraft exhaust will hopefully keep any particulates down below. Besides lip and burner placement furnace will sport perhaps four V shaped clean out troughs that can be uncovered to allow raking out any crap built up if there is any.

Trying to design a burner box that can be added to making it longer for larger applications. Now I need to wrap my head around blowing powdered wood dust. Looking for pulverizer information. And still wondering how to best introduce secondary preheated air (300 to 900 F) into the burn stream.

You're just a few minutes north of me. I'd love to check it out some time if you're willing. Lord knows I've struggled enough with refractory experiments gone bad....[/quote]

I remember melting 2800 degree softbricks, the sucky part is they were my furnace wall.Moral of the story.... Beware of shrinkage coefficients in blanket insulation's.

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