Kilns annular shaft

Annular film reactor, Chemithon, 23 547 Annular flow, 11 772 Annular shaft kiln, 15 48-49 Annulenes, 12 243 Anode(s)... 

The annular shaft kiln consists of a central cylinder that restricts the effective thickness of the burden see Figure 6.14. This ensures a good distribution of... 

Figure 6.14 Annular shaft kiln. (Reproduced by permission of J.A.H. Oates and Wiley-VCH).

Thus the properties of quicklime from a given kiln reflect the average properties of individual lumps, each of which has experienced a particular time-temperature history. Fig. 15.8 compares the distribution of particle densities for a light-burned quicklime from an annular shaft kiln, with a mean apparent density of 1.66 g/cm with that of a solid-burned quicklime from a coal-fired traditional shaft kiln with a mean apparent density of 2.15 g/cm. Table 15.4 presents some typical... 

Figure 15.8. Distribution of particle densities of quicklime (a) from an oil-fired annular shaft kiln (b) from a coal-fired shaft kiln...

The annular shaft kiln (design E in Table 16.1) is shown in Figs. 16.11 and 16.12. 

Figure 16.11. A Beckenbach annular shaft kiln (by courtesy of Beckenbach Warmestelle GmbH)...

Figure 16.12. Cross-section of an annular shaft kiln (a) upper burners (b) lower burners (c) combustion air to upper burners (d) combustion air to lower burners (e) kiln exhaust gases...

Mass balances are a way of ensuring that the measurements of inputs correspond with outputs. This serves as a valuable check that the information is substantially correct, particularly when balances are made for each chemical element. The prime purpose of determining a mass balance is to provide a basis for calculating the heat balance. Table 16.2 lists the input, intermediate and output flows for an annular shaft kiln. 

Table 16.2. Inputs, intermediate flows and outputs for an annular shaft kiln...

K. Bechenbach, Lime burning in the annular shaft kiln , Zement Kalk Gips 5, 1970, 206-209. 

P. Zeisel, Annular shaft kilns with the TREIVO system , Zement Kalk Gips 9,1996, 530-539. 

W. Arnold, Injector air preheating for annular shaft kilns . World Cement, Febr. 1997, 28-33. 

Annular shaft kiln is a type of shaft kiln in which the burden occupies an annulus between a central column and the shell. 

Cover picture A Beckenbach Annular Shaft Kiln... 

Figure 1.2 Schematic diagram of annular shaft 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. 

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