Optimization of clinker cooler performance
with understanding of the heat exchanger challenges
M. Føns, Fons Technology International, Istanbul, Turkey
The efficiency of the clinker cooler in its process engineering function as heat exchanger has a significant effect on the specific heat consumption of a kiln plant. Basically, the task of the clinker cooler is to use the supply of cooling air to return the heat content of the clinker leaving the rotary kiln back to the rotary kiln process as fully as possible in the form of high temperature combustion air and to cool the clinker to such an extent that when it leaves the cooler there is no problem with its onward transport, storage and grinding. The efficiency of the heat exchanger depends substantially on the granulometry of the clinker, the speed at which the material flows through the clinker bed and on the height of the clinker bed on the cooler grate itself. The height of the realizable clinker bed finally depends on whether the process of heat exchange takes place in cross- or countercurrent in thermodynamic terms. The intention of the article is to make the flow conditions in the clinker bed more clearly understandable. As, in reality, the clinker granulometry , i.e. the particle size composition of the clinker are subject to large fluctuations and also the flow of the clinker from the rotary kiln on the cooler grate is associated with a stronger end mix, this article presents a ventilation system patented and developed by the author, which ensures a controlled air flow through the clinker bed dependent on the pressure loss. The flow regulators with the registered trade name STepped Air Flow Function (STAFF) installed below the clinker grate for this purpose are particularly described in detail. For the regulator, which operates with a pressure differential of 50 to 300 mm H2O, a mathematical model is shown. According to the author, the use of the STAFF flow regulator should lead to significant improvements in the Fons Delta clinker cooler, which operates according to the so-called Walking Floor Principle. According to the information given, the use of the STAFF Flow Regulators when retrofitting an existing clinker cooler, in addition to savings of electrical energy, the specific heat consumption of the kiln plant could be reduced accordingly.
Summary CEMENT INTERNATIONAL 02/2017 pp 56-61
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