Title

HOT BLAST STOVES – DESIGN AND CAMPAIGN LIFE EXTENSION

HOT BLAST STOVES – DESIGN AND CAMPAIGN LIFE EXTENSION

Authorship

SMITH, MARTIN; FONSECA, FABIANA

SMITH, MARTIN

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FONSECA, FABIANA

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DOI

10.5151/2594-357x-33Red-3404

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Abstract

The provision of an economic supply of hot blast is central to the efficient operation of the blast furnace. With the increased use of tuyere injectants as fuel, the need for higher blast temperatures and higher oxygen rates has become even more important. Despite the development of a number of possible alternatives over the years, the hot blast stove is still the most cost-effective means of supplying this need. VAI have a long history of designing, building and installing hot blast stoves of both the internal and external combustion chamber type. Both types of stove now include the features necessary to maximise the efficiency of combustion and provide high blast temperatures while minimising the effects of stress-corrosion cracking. Running costs can be reduced by the incorporation of waste heat recovery equipment and the use of computer models for the optimisation of gassing efficiency. Techniques for the retrofitting of modern refractory and burner designs within existing stove chambers have also been developed. The general purpose of this paper is to show the current designs offered by VAI for both external and internal combustion chamber stove designs. For the VAI external combustion stoves, the two stove chambers are designed to expand independently of each other. For the internal combustion the modern design features a mushroom dome arrangement that allows the dome itself to expand independently of the ring walls. Others topics covered are chequer and burner designs. The modern chequer is of “thinwall” construction thus giving a greater specific heating surface while the latest burners allow highly efficient combustion and low emissions levels. The paper describes the current “state-of-the-art” and shows examples of how hot blast stove technology can been used to maintain the competitiveness of blast furnace iron-making.

The provision of an economic supply of hot blast is central to the efficient operation of the blast furnace. With the increased use of tuyere injectants as fuel, the need for higher blast temperatures and higher oxygen rates has become even more important. Despite the development of a number of possible alternatives over the years, the hot blast stove is still the most cost-effective means of supplying this need. VAI have a long history of designing, building and installing hot blast stoves of both the internal and external combustion chamber type. Both types of stove now include the features necessary to maximise the efficiency of combustion and provide high blast temperatures while minimising the effects of stress-corrosion cracking. Running costs can be reduced by the incorporation of waste heat recovery equipment and the use of computer models for the optimisation of gassing efficiency. Techniques for the retrofitting of modern refractory and burner designs within existing stove chambers have also been developed. The general purpose of this paper is to show the current designs offered by VAI for both external and internal combustion chamber stove designs. For the VAI external combustion stoves, the two stove chambers are designed to expand independently of each other. For the internal combustion the modern design features a mushroom dome arrangement that allows the dome itself to expand independently of the ring walls. Others topics covered are chequer and burner designs. The modern chequer is of “thinwall” construction thus giving a greater specific heating surface while the latest burners allow highly efficient combustion and low emissions levels. The paper describes the current “state-of-the-art” and shows examples of how hot blast stove technology can been used to maintain the competitiveness of blast furnace iron-making.

Keywords

Hot Blast Stoves, life extension, rebuilding

Hot Blast Stoves, life extension, rebuilding