New products and new markets clearly help finances. Burning that much gas has got to be their major expense. Are there other way to heat the furnaces?

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GeekyBear 4 minutes ago | parent | next [-]

When they recently decided solar furnaces were not cost effective for electricity production (compared to solar panels), I did wonder if they couldn't be adapted to the production of energy intensive products like glass, bricks, or concrete.

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hhh 4 hours ago | parent | prev | next [-]

Sometimes, but not often. These furnaces burn for like 20 years at a time, so gas is pretty common.

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pfdietz 3 hours ago | parent | prev [-]

Glass furnaces operate somewhere around 1500 C. Electrical heating would work, but that's also quite expensive, usually even more so.

What they'd want to do is try to recover and reuse heat. In principle, there's no reason "new" heat has to be added each time they heat a batch of glass, if heat can be transferred from cooling glass back to the input materials.

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rlonstein 2 hours ago | parent [-]

> What they'd want to do is try to recover and reuse heat. In principle, there's no reason "new" heat has to be added each time they heat a batch of glass, if heat can be transferred from cooling glass back to the input materials.

Have you worked in any industrial or craft setting involving molten glass or metal? Walked around a workshop? There's no way the heat is going back into the process.

	▲	pfdietz an hour ago \| parent [-]
		I know there are industrial processes where heat is efficiently recycled, but I agree there are serious practical problems, particularly if the molten glass must be cooled quickly. Still, even somewhat lower grade heat can be upgraded back to high grade heat with high temperature heat pumps.