Abstract: In the tin float bath process of flat glass production, proposed automatic recuperative natural gas burners will replace the existing electrical heating elements. The use of natural gas instead of electricity creates a more energy-efficient bath operation, amounting to an approximately seventy percent savings. Control of the burner zones is comparable to that utilized with the replaced electrically heated zones. Combustion air and natural gas are ignited and burned within a heat-radiating chamber. The residue from burnt gases is exhausted externally to the bath and has no contact whatever with the atmosphere inside the bath. Advantages comprise a less complicated installation with minimal maintenance and with little or no replacement parts, all of which contribute to longevity not attained by prior art. Additionally, shutdown of the process is not necessary to remove and replace a possible defective burner, as is required with defective electrical heaters. Only periodic visual inspection is required.

Abstract: A unit for heating initially solid asphaltic material to provide asphaltic concrete in a condition suitable for application. The unit is operated to heat initially cold material to a temperature between 275.degree. and 300.degree. F. and to maintain it at that temperature until it is used. A thermostatic control system produces heated air intermittently in accordance with a predetermined schedule, and the heated air is used to heat the asphaltic material.

Abstract: Asphalt heating kettle with improved temperature control to prevent overheating, and with improved gas fuel pilot light to prevent pilot blowout. The temperature sensor for the kettle is housed in an apertured tube in direct heat transfer contact with a burner flue within the kettle, so that the temperature both of liquid asphalt and of the flue itself is sensed to prevent an overheat condition. The pilot burner is located behind the main burner, upstream of the high-velocity flame from the main burner, so as to be unaffected by the blast or shock wave of main burner ignition.

Abstract: Method and apparatus for the heat treatment of volatile containing materials in a rotary hearth type furnace wherein the flue gases emanating from the calciner are employed to create either a positive or negative pressure within the calciner hearth as well as the soaking pit area of the said calciner.

Abstract: Disclosed is a new and improved method for automatically balancing the temperature of a plurality of reversing heat exchanger units provided in parallel relation with each other. The balancing method comprises the steps of: detecting the temperature in portions of each core of the reversing heat exchangers whenever the flow paths of a feed stream and a heat medium stream are changed over, calculating a mean temperature of each core from the said detected values during the most recent certain changeover period from the current time point, calculating a mean temperature for all exchangers from the said calculated mean temperatures of each core, calculating deviation and deviation trend in temperature of respective exchangers depending on a difference between the mean temperature of each core and the mean temperature of all exchangers, feeding back a system deviation in dependence on the said deviation and deviation trend to control valves for balancing the temperature of reversing heat exchangers.