The Headache of Cold Spots in Glass Tunnel Kilns
If you’ve ever run a finishing line for oversized glass, you know the struggle. You’ve got these massive sheets moving through the kiln, but most standard lamps only come in 1-meter lengths. That leaves gaps. Those little cold spots might seem minor, but they’re a nightmare. They lead to uneven tempering and those annoying optical distortions that make a piece of glass look “off.” To fix this, we stopped trying to make standard lamps work and started building continuous infrared units that stretch well beyond 2 meters.
The Trick to Long Tubes
You can’t just stretch a piece of quartz and call it a day. If you do, you’re asking for trouble. The real challenge is managing the voltage and current. If you just pump power into a long tube without a plan, you’ll get a massive hot spot right in the center. That’s how you get quartz that bows or, worse, just burns out. We spend a lot of time dialing in the wattage-per-centimeter. We want the heat to feel exactly the same at the very end of the tube as it does at the start.Consistent heat, no surprises.
Building for the Heat
We use high-purity quartz because it can take the beating of continuous operation. But the real secret is in the end-caps. Think about it: a 2-meter tube grows quite a bit when it gets screaming hot. If the seals are too tight or poorly designed, the tube will literally pop out of its socket. We use specific sealing techniques to give the glass room to breathe as it expands. Plus, these are designed to sit side-by-side. You can wire them up in long banks, essentially creating a solid wall of infrared energy.
A Few Things to Watch Out For
Here’s the honest part: these units put a serious load on your electrical panels. Before you install them, double-check your wiring gauge. You don’t want your wires overheating because they can’t handle the continuous amperage. And a word of caution on the installation. These long tubes are fragile. One wrong move or a clumsy bump while you’re dropping them in, and crack—there goes your afternoon. We always suggest using support brackets every 500mm. It stops the tubes from sagging under their own weight and keeps everything safe.