Engineering360: "Reducing fuel costs in process ovens and dryers"

Many years ago, I designed and built a drying oven for curing a cellulose based lacquer. It was approx. 40' long x 8' wide & 12' high; it had two levels and about 12 runs of conveyor running the length (6 on bottom, 6 on top). It fed in at the top & out at the bottom, both through the same opening, which had a extract duct to stop any fumes escaping into the atmosphere. Internally it had two boxes the size of the internal dims, 6" deep (one at the top, one on the bottom), the top fed by a combustion chamber on top of the oven. This forced hot air down through the product and sucked into the bottom collector box; by way of a duct, it was sent back up to the combustion chamber to be heated up with the process starting again. The gas supply was controlled by a variable gas valve linked to thermostats around the drying chamber; we noticed that after the initial start up, when the oven was empty, the gas valve was at 100%. When the product entered and the fumes were being sucked into the fire box the valve shut down to as much as 50%, meaning we were burning fumes mixed with gas. It made the process extremely efficient by accident, but I said it was planned that way anyway. Big pat on the back, but no pay raise.

I can see some of the efficiencies in a regen affect as well as possibly an oxider effect to your NCG’s?...