Objective
To increase the production of a cement plant by 23.5% and lower its fuel consumption by adding a rotary cooler with peripheral blowing nozzles in the lower part of the rotary klinker kiln. Through this rotary cooler, klinker is cooled by injected cold air which is then used directly as preheated air for the firing of the fuel in the firing section of this same kiln. Expected energy saving is 5,000 TOE/yr. Expected payback time approximately 1,5 years.
In the first series of experiments, mechanical, electrical as well as problems related to the bloking of the orifices were noticed. In the second series of experiments serious problems connected with the quick deterioration of the different types of refractory materials used were experienced. These problems, enforced by the doubt related to the limited extent of the commercial potential of this technology, made the contractor decide the termination of the project.
In the conventional production process, klinker leaving the rotary kiln is cooled via an aerated mooving bed. These long cooling trays can be expensive in space and can create problems related to the recuperation of the warmed cooling air. In this project the lower part of a conventional rotary kiln was extented by a length enough to cool the outflowing hot klinker by the use of cold air injected through a number of peripheral nozzles. In this way the temperature of the klinker leaving the kiln will be lowered helping further the existing cookers to cope with more product. Additionally more heat can be recuperated, less maintenance of the kiln exit rings can be anticipated, while the quality of the produced klinker can be approved.
The actual extention of the length of the kiln was 2,7 meters incorporating nine rows of blowing nozzels with 22 orifices each, or a total of a 198 air injection points. Air supply was handled by a large circular air duct fed by four ventilators fixedon the supporting structure of the kiln. Air injection was controlled by a series of valves so activtaed as to open to allow air to be blown only through the mass of the klinker at the lower part of the periphery of the kiln.
Programme(s)
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
92156 Suresnes Cedex
France