Dealing with the Headache of Long Glass Annealing Tunnels
Standard infrared lamps just aren’t built for the scale of modern glass production. If you’re running a tunnel kiln for oversized sheets, you’ve probably seen the problem: you line up dozens of short lamps, and you end up with “cold spots” at every single joint. It’s a mess. We figured there was a better way. So, we started building custom infrared units that stretch past 2 meters. The trick is in the power. You can’t just stretch a standard lamp and hope for the best. If you do, you’ll deal with massive voltage drops, and the center of that 2-meter tube will be lagging way behind the ends. That’s how you get bowing or uneven annealing. To stop that, we tweak the filament and the quartz envelope. We play with the ohms and voltage until the watt-density is dead even across the whole span. No weak spots. Just steady heat. Then there’s the physical side of things. When you’re dealing with a span of 2000mm or more, thermal expansion is a real beast. If your mounting brackets are too tight, the tube doesn’t have anywhere to go when it heats up.Snap. We use heavy-duty quartz and design the supports to let the lamp “breathe.” It gives the glass room to move without breaking. As for the wiring, we use connectors that can actually take a beating. Constant heating and cooling usually shakes things loose, but we prioritize hardware that stays put. A few things to keep in mind… Longer lamps are great because they mean fewer electrical connections to manage. But there’s a trade-off. These units pull a lot of amperage. You’ll want to double-check that your control panels can actually handle the load. And a quick tip: make sure your cooling fans are positioned to clear the heat away from the lamp ends. If that heat builds up, you’ll burn out your sockets faster than you can replace them.