Integrated reaction process
AssigneeThe Associated Portland Cement Manufacturers Limited
InventorsAnthony Robin Pennell, Peter Leslie Dover, William Martin Davies
Life of this patent
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Abstract
A process in which a substance undergoes endothermic change within a predetermined temperature range in at least one stage of the process and is subsequently subjected to a substantially higher temperature in a further stage of the process, characterised in that effluent heat from said further stage is augmented and the resultant supply of heat is applied partly to the generation of power, and partly to said endothermic change.
Claims17
A thermal calcination process comprising the steps of:
- a. passing raw material through at least one heating zone wherein heat energy is applied to produce endothermic change in the material;
- b. passing the hot material treated in step (a) into a reaction zone wherein further heat energy is separately applied to produce exothermic change in the material;
- c. passing the still hotter material treated in step (b) through a cooling zone and recovering a cooled reaction product therefrom;
- d. supplying to said reaction zone a first source of heat energy in sufficient quantity and at a sufficiently high temperature to support said exothermic change;
- the said endothermic change of step (a) being all dependent upon at least one source of heat energy other than said first source;
- e. supplying a second source of heat energy to a boiler and applying said heat energy for raising steam and thereafter for producing at least part of the endothermic change in said material in step (a);
- f. augmenting said second source of heat energy by adding thereto heat recovered from at least one process zone including heat derived from the reaction zone;
- and
- g. employing steam raised in the boiler for the generation of power.
In a process of making Portland cement clinker which comprises continuously passing Portland cement raw feed mix through a first region in which endothermic change is effected in the raw feed mix and then through a sintering zone while applying sufficient heat to the process to recover Portland cement clinker, the improvement which comprises:
- a. physically separating the first region from the sintering zone;
- b. firing fuel along with combustion air in said sintering zone to generate heat at a first rate and temperature sufficient substantially completely to sinter the decarbonated mix therein and recover said clinker only when the mix received from said first region is substantially completely decarbonated;
- c. passing the effluent gas from step (b) directly into said first region to provide sufficient heat as only partially effects decarbonation of the feed mix within said first region;
- d. extracting heat from the hot recovered clinker by flowing air to recover cooled clinker and heated effluent air;
- e. firing fuel separately from step (b) in the heated effluent air of step (d) to generate heat at a second rate which is much greater than said first rate;
- f. applying the heat generated in step (e) to said decarbonation zone and to a boiler, said second rate being sufficient substantially completely to decarbonate said mix in the decarbonation zone and to generate steam from the boiler;
- and
- e. employing steam generated by the boiler for the generation of power.
Dependencies are inferred from the claim text.