Parallel-flow regenerative kiln

Three aspects are common to all shaft kiln designs, namely charging, drawing of the ore, and combustion. A shaft kiln is essentially a vertical refractory lined cylinder or ellipse. The ore is charged in at the top of the furnace, along with, in some cases, a solid fuel such as coke or anthracite coal. Other fuels such as natural gas and oil can also be employed. There are a number of different variants of shaft kilns, such as the mixed feed, traditional type and modern basic design, annular, parallel-flow regenerative, double inclined, and multichamber. 

The parallel-flow regenerative kiln consists of two interconnected vertical cylindrical shafts. Burden is charged alternatively to each shaft and drawn downward through a preheating heat exchange zone and into the calcining zone. 

Figure 16.13. A pair of Maerz parallel-flow regenerative kilns (by courtesy of Buxton Lime Industries Ltd.)...

Figure 16.14. Cross-section of a parallel-flow regenerative kiln...

X. Liang et al., The first parallel-flow regenerative lime shaft kiln in the Peoples Republic of China , Zement Kalk Gips 7,1988,328-333 (English 9,1988,208-211). 

For example, a natural gas-fired parallel-flow regenerative kiln produces about 0.951 of C02/t of quicklime, of which 0.731 arises from the dissociation of the quicklime and 0.221 from the combustion of the gas. The use of less efficient kilns and fuels containing higher proportions of carbon would result in corresponding increases in the amount of CO2 emitted per tonne of lime. Carbon dioxide as-... 

Parallel flow regenerative type Modern with recuperators such as cooler type, preheater kilns and internals Horizontal ring type, grate kilns, etc. 

G. Schaefer, Heat consumption limits of parallel-flow/counterflow at combustion of lime regenerative kilns , Zement Kalk Gips 1,1981,36-41. 

J. Liebl, Construction and operation of the first pulverised coal-fired 300 t/d parallel flow/counter-flow regenerative kiln in the Federal Republic of Germany , Zement Kalk Gips 9,1988,417-422 (English 11,1988,246-249). 

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