1972 Volume 58 Issue 5 Pages 651-659
The technique of high blast-temperature operation of blast furnace is advantageous in that it can reduce coke ratio and increase production of hot metal. Therefore, it is now a common practice to operate blast furnace with blast temperature over 1 100°C. With the advent of large, high top-pressure blast furnace operations, however, an increase in physical load caused by rising inside temperature and pressure due to high blast temperature leads to troubles in equipments. This is the bottleneck of such operation.
By adopting the following measures, we have achieved a satisfactory operation of No 1 blast furnace at our Kakogawa Works with blast temperature of 1 250 to 1 300°C.
(1) Adoption of Martin type hot stoves.
(2) Increase in thickness of the linning of hot main and bustle pipe and improvement of their structure.
(3) Adoption of blowing stock with two-fold linning structure.
(4) Increase of dome temprature of hot stoves through adoption of air preheater.
(5) Protector for hot blast valves.
(6) Control of charging material for blast furnace and adjustment of gas distribution by using movable armour and sampling equipment of furnace gas.
The basic construction plan for No 2 blast furnace at Kakogawa will be worked out based on our experiences in No 1 blast furnace. Furthermore, through lap parallel operation with four hot stoves and hot blast valves made of steel plates etc., we are intending to establish a technique of high blast temperature operation for a large, high top pressure blast temperature operation for a large, high top pressure blast furnace of 4 000m3 class.