Getting Glass Annealing Right with Ultra-Long IR Heaters
If you’ve ever dealt with continuous glass annealing, you know the struggle. You need a perfect thermal gradient across the whole tunnel, or you’re looking at internal stress and broken glass. The problem? Standard lamps are usually too short. You end up with these annoying gaps in your heat profile. We solved that by building custom infrared units that stretch past 2 meters.
The trick to long-form tubes
You can’t just stretch a quartz envelope and call it a day. If you do, you’ll get hot spots. And hot spots mean cracked glass. To stop that, we play around with the wattage per centimeter. We usually go with high-voltage setups to keep the current flowing steady from one end to the other. It keeps the heat uniform. One quick heads-up: check your power supply. An array this long pulls a lot of current. If your wiring is too thin, you’ll get voltage drops, and your annealing will be all over the place.
Keeping things sturdy
Here’s the thing about 2-meter tubes: they want to sag. When they get hot, gravity takes over and they start to bow. To fix this, we use heavy-wall quartz glass. It’s tougher. We also add reinforced supports and special end-caps so the tube stays straight and safe. Depending on how thick your glass is, you can go with shortwave or medium-wave. Shortwave digs deep into the glass, but it’s a bit harder on the surface. Medium-wave is your go-to if you just need to stabilize the surface temperature.
Getting them in and out
We don’t want you fighting with the alignment for hours. That’s why we use precision-machined mounts. You just slide the units into the tunnel and they click right into place. But be careful during maintenance. The longer the tube, the easier it is to snap. Don’t try to manhandle these during a swap-out. Use a dedicated lifting jig. It’ll save you from the headache of replacing a shattered quartz tube.