Blast Furnace Tuyeres and Tuyere Stocks May29

Blast Furnace Tuyeres and Tuyere Stocks...

Blast Furnace Tuyeres and Tuyere Stocks The blast furnace (BF) has the objective of extracting the hot metal (liquid iron) from iron ore lump, sinter and/or pellet, coke and injected fuel. This objective is achieved by passing a hot enriched air flow (hot blast air) through the ore and coke burden which goes down in the internal column of the BF. The hot blast air and auxiliary fuel are injected into the blast furnace through tuyeres located around the perimeter of the BF. The upper zone of the hearth wall of the blast furnace contains the openings for the tuyeres which are used to introduce the hot blast air into the furnace. The furnace jacket in the tuyere zone contains steel reinforced openings within which copper (Cu) cooled elements are installed, similar to that shown in Fig 1. The steel reinforcements in the jacket are called tuyere cooler holders. The large Cu cooler which is installed within the machined inner surface of the cooler holder is called the tuyere cooler. The Cu cooler which actually introduces the hot blast air into the furnace is called the tuyere. It is installed within a machined, inner seating surface on the tuyere cooler. The blowpipe is part of the tuyere stock air distribution piping, which delivers the hot blast air from the bustle pipe, and which mates with the tuyere, to direct the hot blast air into the furnace. The tuyere breast walls are usually made of carbon brick and the cooling is generally external with jacketed cooling channels on the outside of the shell. Some furnaces have internal staves in the tuyere breast between the tuyere coolers as a cooling design for the tuyere breast. Fig 1 also shows the arrangement of the tuyere cooler holder,...

Air Blast System for Blast Furnace Jan29

Air Blast System for Blast Furnace...

Air Blast System for Blast Furnace A blast furnace (BF) produces liquid iron (hot metal) by the reduction of ore burden with reducing gases. The reducing gases are produced by the reaction of oxygen with coke and coal. This oxygen is part of enriched hot air blast which is blown and distributed at the bottom of the BF through the straight pipes, blowpipes and the tuyeres. This set is connected to the main bustle pipe. The volume of air which is enriched with oxygen and blown for the process in the BF to take place is provided by the air blowers. These air blowers take the air from atmosphere and compress it to the required pressure. This compressed air which is at about up to 200 deg C temperatures after compression is enriched with oxygen and blown into the hot stoves where the temperature is raised up to 1.200 to 1250 deg C. This hot blast air is then taken to bustle pipe through hot blast main. Air blast systems of modern high capacity blast furnaces operate with blast temperatures of up to 1350 deg C and blast pressures up to 5 kg/sq cm (g). The whole process is typically shown in Fig 1. Fig 1 Schematics of typical air blast system The main components of an air blast system of a blast furnace consist of (i) air blower, (ii) cold blast main, (iii) hot blast stove along with its combustion system, (iv) hot blast main, (v) bustle pipe, (vi) blow pipes and tuyeres known as tuyere stocks, (vii) set of valves, and (viii) control instruments. The air blower is the first equipment in the air blast system. It is located in the blower house and is meant for providing cold air blast to the...