Getting Rid of Cold Spots in Long glass Tunnel Kilns
If you’ve ever worked with ultra-long tunnel kilns, you know the headache of “cold spots.” You’re moving glass through the heat, but right where one standard lamp ends and the next begins, there’s a gap. A tiny dip in temperature. It doesn’t sound like much, but in glasswork, it’s a nightmare. That’s why we build custom infrared heating units that stretch over 2 meters. No gaps. Just one long, steady wall of heat. The struggle with power Here is the thing about going long: voltage drop. When you’re pushing power across a unit that’s over 2 meters, the electricity doesn’t always play fair. If you aren’t careful, the ends of the array can burn out or the middle can lag. We spend a lot of time balancing the electrical load. We make sure the wattage is exactly the same at the first centimeter as it is at the last. Your glass shouldn’t “feel” the difference as it travels. It just stays hot. Creating a wall of heat We don’t do modular setups here. Why? Because joints create lines. By packing quartz tubes into a tight, continuous row, we create a solid radiation wall. This is a lifesaver for large-scale processing. When you get rid of those thermal gradients, you stop the internal stress and warping that ruins a batch. Depending on how thick your glass is, we’ll use short-wave or medium-wave emitters. If you need the heat to punch deep and fast, short-wave is the way to go. The “gotchas” of installation Let’s be real—wiring up a 2-meter unit is a bit more work than popping in a few small lamps. First, you can’t just hang these. Quartz tubes are fragile, and over that length, they want to sag. You’ll need a heavy-duty mounting frame to keep everything straight and safe. And a heads-up on the heat: these arrays put out a massive amount of ambient energy. If your ventilation is an afterthought, you’re going to have a problem. You don’t want your control electronics or sockets frying because the air has nowhere to go. Double-check your cooling system—it needs to be able to handle the total BTU output of a run this long.