Abstract: This invention relates to a method to further enhance NOx reduction in rotary preheater mineral kilns by coupling the temperature control and gas composition uniformity afforded by the high temperature mixing with the use of chemical reducing agents. The chemical reducing agent or agents, generally chosen from ammonia or ammonia precursors, are introduced at a specific point in the rotary preheater kiln which has as an optimal temperature window to achieve the greatest reduction of NOx emissions.

Abstract: This invention relates to a method to further enhance NOx reduction in rotary preheater mineral kilns by coupling the temperature control and gas composition uniformity afforded by the high temperature mixing with the use of chemical reducing agents. The chemical reducing agent or agents, generally chosen from ammonia or ammonia precursors, are introduced at a specific point in the rotary preheater kiln which has as an optimal temperature window to achieve the greatest reduction of NOx emissions.

Abstract: A system for cooling a single or plural zones of the exterior of a furnace or similar hot device, e.g., kiln, calciner, etc. Each zone is cooled by a respective cooling assembly. The operation of the assemblies is effected by a common control system. Each cooling assembly comprises a shroud, an induction cooler, e.g., an exhaust fan, and at least one atomizing spray nozzle. The shroud is in the form of a jacket disposed over the associated exterior zone of the furnace and is spaced therefrom to form a cooling chamber therebetween. The exhaust fan is coupled to the shroud for inducing the flow of cooling air through the cooling chamber so that it absorbs heat from furnace's exterior. The atomizing spray nozzle is also coupled to the shroud and to a water and an air supply for introducing atomized droplets of water into the chamber, whereupon the droplets vaporize to absorb heat from the furnace's exterior. The exhaust fan vents the air and steam from the shroud means.