Karpenko S. Improve efficiency to heat blast-furnace air by means of enhancement of heat exchange features and work patterns for Cowper Stoves-heat exchangers.

Thesis is dedicated to solve actual scientific and technological issue to improve the efficiency of blast-furnace air heating. It's established that in the process of using pulverized coal in the blast-furnace (up to 160 kg/t) instead of natural gas (up to 110 m3/t) the specific yield and heat value of blast-furnace gas are decreased up to 33,7 and 14,7 % correspondingly. The root cause of low resistance of heat exchangers (2,3-3,5 years) is the sulfuric acid corrosion of tubes. If low-sulfur coke (0,70 instead of 1,29 %) and pulverized coal (S = 0,40 %) is used in the blast-furnace the concentration of sulfur oxides in the flue gases is significantly decreased (from 190-192 up to 2-3 mg/m3). That results in improvements of heat exchanger life. The mathematical model and computer program to calculate new design of heat exchangers with cross and counter flow of heat carrier and air (gas) preheat have been established. There is a potential to furnish CS unit in use with heat exchanger system to heat combustion products. There is dependency between the temperature rise of CS flue gases and their heat exchange settings and also weight and dimensions of checkerwork. The new generation of CS and heat exchangers to heat combustion products is designed. The special feature of CS is the usage of dome heating, high temperatures of flue gases and checkerwork with high efficiency configurations and horizontal passes. Expected economic effect is 2,7 million UAH/year. Keywords: Cowper stoves, heat exchangers, pulverized coal, sulfur acid corrosion, modeling, resistibility, material intensity, efficiency.