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Show PYRETRON, A VARIABLE GAS/OXYGEN/AIR COMBUSTION SYSTEM Gregory Gitman American Combustion, Inc. Atlanta, Georgia, USA ABSTRACT This paper presents the engineering principles behind a new variable gas/oxygen/air combustion method called PYRETRON~M The Pyretron increases flame luminosity and velocity by using oxygen to accelerate the pyrolysis of natural gas inside an extremely hot flame core contained in a specially structured and controllable flame envelope. In addition, the system provides increased controllability of the chemical inputs to provide for an excess hot oxidizer when needed for refining or to reduce the oxidation ability of combustion products when they will negatively impact product quality. These advances have application in the melting of copper, steel and aluminum, in the forging and rolling of steel where the process is sensitive to combustion products and in processes such as the melting of glass and the heating of ceramic products where both the product and the furnace are sensitive to uneven temperature distribution. The paper specifically illustrates the operating advances of the Pyretron from experience gained in steel making applications. INTRODUCTION Most combustion processes use ambient air as the source of oxygen. During combustion the reaction of this oxygen with carbon and hydrogen in the fuel provides useful thermal energy, a major portion of which is absorbed by the nitrogen in the combustion air. When 171 pure oxygen is introduced, the vulume of nitrogen in the combustion gases is reduced leaving potentially more useful heat available. The general utilization of oxygen for industrial heating began in the early 1950s and since this period many attempts have been made to use oxygen to improve heating efficiency. Recent increases in the cost of fuel relative to oxygen have spurred new int erest in oxygen utilization for high temperature heating and melting applications. Oxygen enriched air burners and oxy-fuel burners are the most common methods of introducing oxygen into combustion. These methods were developed using two different design approaches. Oxygen enrichment was developed for applications where existing combustion hardware could be adapted to use small amounts of oxygen with minimum capital expense. This approach led to broad oxygen enriched air utilization in old reheating furnaces and soaking pits. However, oxygen enrichment above 24% has been limited because of the increasingly negative effects such as local hot spots, nonuniform load heating and excess oxidizing and decarburizing. On many occasions the reported fuel savings achieved through oxygen enrichment in furnaces using preheated combustion air have created misleading conclusions about oxygen's contribution to overall efficiency improvements. The theoretically possible effects of enrichment of preheated air shown in Figure 1 verifies the suspicion that the usual practice of tuning the ent ire combustion system at the time of modernization with oxygen enrichment resulted in substantially greater energy savings than can be attributed to t he use o f oxygen. A review of performance results |