| 摘要 |
<p>The invention relates to a process for preparing lime and carbon dioxide by decarbonization of the starting material consisting of limestone as powder extracted from lime pits and calcareous flour resulting as a by-product from the nitrogenous fertilizer manufacturing process. The starting material circulates by gravity through some vertical channels, being heated up to a temperature of 840°C by the smoke gas which circulates in counter-flow with the starting material. The smoke gas is formed by burning gaseous fuel with comburant air which cools the lime resulting from decarbonization down to 30°C. The air is introduced into the bulk lime under some metal pieces in the shape of a reverse V and the gaseous fuel is introduced at a level which is 20 cm-higher than the said metal pieces, after passing upwards through the starting material heating zone, as well as through an additional height for cooling the smoke gas. When the moist lime is dried, the smoke gas is sucked in, through some orifices cut in one of the furnace walls, at the level of some reverse V-shaped channels, and then are discharged through a metal stack. The cold lime is extracted through a flow rate-regulating gate, wherefrom it is sent to be processed by hydration or to be used otherwise.</p> |
