Shaft furnace

Shaft Furnaces The oldest and most important application of the shaft furnace is the blast furnace used for the production of pig iron. Another use is in the manufac ture of phosphorus from phosphate rock. Formerly hme was calcined exclusively in this type of furnace. Shaft furnaces are widely used also as gas producers. Chemicals are manufac tured in shaft furnaces from briquetted mixtures of the reacting components. 

Schacht-ofen, m. shaft furnace blast furnace shaft kiln, -speicber, m. (Metal.) storage bin (Agric.) silo, -trockner, m. tunnel drier. 

Flow of gas in the blast-furnace shaft. U. S. Bur. Mines Rept. Investigations 2978. 

Type of furnace Shaft furnace with rotary grate... 

Units Rotary furnace Hearth type furnace Shaft fiimace Crucible furnace ... 

To change the offtake system of an existing cupola from above to below the charge-hole system is in most cases impossible. Post combustion of the waste gases in the furnace shaft therefore is a more viable solution for cupolas with an above charge-hole offtake. 

Alternatives to straight-line horizontal continuous furnaces are rotary hearth (disc or donut) furnaces (fig. 1.8 and secs. 4.6 and 6.4), inclined rotary drum furnaces (fig. 1.10), tower furnaces, shaft furnaces (fig. 1.11), and fluidized bed furnaces (fig. 1.12), and liquid heaters and boilers (sec. 4.7.1 and 4.7.2). 

In simple terms, the furnace shaft may be divided into fom zones. 

There must be careful balancing of operating parameters to achieve the necessary temperatures and heat balance in various sections of the furnace shaft. Zone 1 snpplies the heat and CO to drive the furnace and must receive the required amount of coke to achieve the leqniied temperature and to generate reduction gases at the base of the shaft... 

Although the above calculations are simplistic they can be used to clearly illustrate the impact of key process parameters on furnace performance, such as the CO C02 ratio in exit gas, the Pb content of sinter, the blast rate and the oxygen content of blast air. There are other practical limits on these parameters to maintain practical operating temperatures at various regions in the furnace shaft, and to minimise the formation of accretions and other obstructions. 

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