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Limestone calcination in a rotary kiln

News Date:2017-04-18 09:09:03

 Limestone calcination has been carried out in a highly instrumented pilot-scale rotary kiln. Local gas, solids, and wall temperatures and pct calcination have been measured under a range of operating conditions to determine the influence of limestone type, feed rate, rotational speed, inclination angle, and particle size on calcination and heat flow in the kiln. Thus, it has been found that the local calcination is dependent primarily on the solids temperature and hence on heat transfer. Of the variables studied, the limestone feed rate has the strongest effect on the temperature and calcination fields, whereas inclination angle and rotational speed are relatively less important. The different limestones studied exhibited significant differences in heat-absorption capacity and calcination temperature which may be related to their radiative properties. Increasing particle size over a range of 0.75 to 3.5 mm resulted in an increase in both heat transfer to the bed and calcination.

Rotary kiln 2,5х75 m Performance data
 

Rotary kiln
Type
Operating type
Drum volume (m3)
Mass (kg)
RK 1.6x8
Parallel flow
continuous
16.0
12 400
RK 1.6x10
Parallel flow
continuous
20.1
13 500
RK 1.6x16
Parallel flow
continuous
32.0
17 800
RK 2.2x14
Parallel flow
continuous
52.3
33 625
RK 2.5x75
Parallel flow
continuous
 
 
RK 2.8x14
Parallel flow
continuous
84.08
48950 – 53 700
RK 2,8x14
Counter flow
continuous
84.2
61 200
RK 2,8x20
Parallel flow
continuous
120.1
72 930
RK 3,5x27
Parallel flow
continuous
250.0
200 000

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