How to Handle Heat Gaps in Ultra-Long Glass Tunnels
If you’ve ever run a glass tunnel kiln, you know the nightmare of “cold spots.” They’re the enemy. Most standard IR lamps stop at about a meter, but when your tunnel stretches past two meters, those gaps become a real problem. You get uneven heat, which leads to glass stress, defects, and a lot of wasted material. It’s frustrating. And expensive.
Getting the Power Right
When we build these custom long-format units, we don’t just guess. We sit down and figure out exactly how many watts per centimeter your specific glass throughput actually needs. Here’s the thing: for anything over two meters, we usually go with higher voltage. Why? Because it keeps the current draw low. That means we can use thinner wiring without worrying about everything burning out. But be careful. You’ve got to make sure your power supply can actually handle the total load. If you cram too many high-wattage lamps onto one circuit, you’re just going to keep tripping your breakers all day.
The Hardware: Quartz and Layout
We use high-purity quartz because, frankly, it’s the only thing that can handle this kind of heat density without giving up. We center the filament so the heat hits the entire width of the glass sheet evenly. No stripes, no weird patches. For these long runs, we line the lamps up end-to-end. We keep the spacing as tight as possible to keep that heat flow constant. One detail people often overlook? Sagging. When quartz gets that hot, it wants to bow. To stop that, we put in rigid mounting brackets every 300mm to 500mm. It keeps everything straight and true, even at peak operating temps.
The Real-World Setup
Installing these requires a clean footprint. We use heavy-duty connectors because factory floors are rough—they take a beating, and your gear needs to be just as tough. Just a heads-up: when you put this much heat in one spot, the air around your conveyor is going to get hot. Really hot. Make sure you’ve got your cooling fans and ventilation sorted out. You don’t want the outer shell of your kiln overheating just because the inside is doing its job.