The Headache of Cold Spots in Long Glass Kilns
Most infrared lamps stop at about 1.5 or 2 meters. That’s fine for small setups, but if you’re running an ultra-long tunnel kiln, those little gaps between lamps become a real problem. You get these “cold spots.” And when glass hits a cold spot after being heated, it doesn’t like it. It expands unevenly, and then—snap—you’ve got breakage. We fix this by building custom heating units that actually go beyond that 2-meter limit. No gaps. No surprises.
The Trick to Long Tubes
You can’t just stretch a piece of quartz and call it a day. If you do, the filament will either sag in the middle or just burn out completely. To stop that from happening, we tweak the voltage and wattage. We usually go with higher voltage setups. It keeps the current under control and means we don’t have to use ridiculously thick wiring to feed the unit. The result? You get a smooth, steady heat across the entire length. Just a heads-up, though: these high-wattage tubes pull a lot of power. Make sure your controllers can actually handle the load, or you’re asking for trouble.
Getting the Heat Right
We use heavy-wall quartz because these long spans take a lot of mechanical abuse. To get the heat into the glass fast, we stick with short-wave or medium-wave emissions. The layout is where the magic happens. We line them up in tight, continuous rows. This kills the “zebra effect”—those annoying alternating hot and cold stripes that show up when your lamps are spaced too far apart.
The Trade-offs (Because Nothing is Perfect)
We can build these as drop-in replacements or design them from scratch for a new line. But here’s the thing: the longer the tube, the more fragile it gets. They vibrate. They flex. You can’t just slide these in and hope for the best. You need precision mounting brackets, otherwise, the tubes might snap during thermal cycling. And if your kiln vibrates a lot? Tell us. We’ll add reinforced end-caps so your seals don’t leak.