Abstract: A cooling element for a metallurgical furnace in which a body of cast material has cooling tubes and adapted to face the interior or the furnace and is transversely spaced opposite marginal portions. The marginal portions of the cooling element are provided with alternating tooth-like configuration having teeth and tooth gaps between them. The cooling tubes or pipes have two inlet planes and two outlet planes. The inlet ends of the cooling pipes are alternately located in one inlet plane and in the other inlet plane and are alternately located in the one outlet plane and the second outlet plane.

Abstract: The invention herein is directed toward a process for the conversion of oxides of nitrogen to nitrogen gas by employing a reactant carbon fiber or inter host carbon material at a temperature of about 550.degree. C. The reactant material can be utilized alone or on a support material; in reactors such as fixed bed, fluid bed and radial flow; and, if desired, can be regenerated during the conversion process.

Abstract: A method for treating an exhaust gas containing nitrogen oxides, oxygen and soot, in which the nitrogen oxides are selectively reduced into nitrogen by adding ammonia to the exhaust gas as a reducing agent under existence of a catalyzer, is improved in that the nitrogen oxide is removed by introducing the exhaust gas into a denitration reactor in which a plurality of planar catalyzer packs or catalyzer packs having gas passage holes are arrayed in parallel to a gas flow and a linear velocity of the gas through the reactor is selected at 4-15 m/s. In one preferred mode of the method, soot having a relatively large particle diameter is preliminarily removed by a dust remover disposed upstream of the reactor, while most of the remaining soot is removed by a high performance dust collector disposed downstream of the reactor. Denitration reactor structures suitable for the improved method for treatment are also disclosed herein.