Use of Refractories for Stove to Supply Hot Air Blasts to Blast Furnace

A hot blast stove is a facility which is used to supply continuously the hot air blast to a blast furnace. Before the blast air is delivered to the blast furnace tubers, it is first preheated by passing it through regenerative hot blast stoves that are heated primarily by the combustion of the blast furnace top gas. This causes some of the energy of the top gas to be returned to the blast furnace in the form of sensible heat. Especially in the checker chamber, the checker bricks having several gas holes, get piled up. This plays a major role in storing the heat provided by the hot combustion gas.This, however, improves the efficiency of the process. Apart from all these, the additional advantage is that it results from the lower fuel requirement and increases the hot metal production rate.

Characteristics of a modern hot blast stoveIn order to achieve the high flame temperature required for the higher hot blast temperatures of 1000 deg C to 1200 deg C, the calorific value of blast furnace top gas is not high enough in value. In order to obtain the high flame temperature, the stoves’ blast furnace gas is basically enriched by the addition of a fuel having higher calorific value, such as coke oven gas. However, most of the modern blast furnaces are having hot blast stoves, which have burners designed for the use of only the blast furnace gas.

Hot blast stoves designed for trendy blast furnace have the following characteristics.

• Achievement of high-efficiency combustion even in the operation with only blast furnace gas. • Smaller heat radiation from the stove body. • Low construction costs. • High stove service life • Complete elimination of stress corrosion cracking.

Characteristics of refractories required for hot stove furnacesBeside one blast furnace, three or four hot stoves are installed and operated alternately in combusting fuel and in blowing hot blasts of 1100 - 1300?. When exposed to high temperatures, the hot stove refractories should be highly durable against compression under high temperature for a long duration with a minimal deformation.

General requirements of hot stove refractories are • Volumetric stability at relatively high temperatures • Little residual shrinkage • High specific heat • Thermal spalling resistance • Corrosion resistanceIndia is a leading manufacturer of stove refractories. Each and every refractory is being constructed maintaining the industrial guidelines and under the vigilance of the expert professionals.

Thus, to conclude, stove refractories have certain characteristics that make it specific for the blast furnace.