Cement and Energy

clinker with a lower volume of air. This means aerating the cooler ca n improve the thermal efficiency ·of the ki ln/cooler system hy more than five per cent. FiRure 3 Spyrometer imaf?e shows various "lwlspols" inside !he kiln. 1hese tJrove viwl in 1he conlrol process. These coolers also address the reliability problem of conventional grate coolers. Direct aerated coolers are designed to operate wi th a thick bed of clinker on the front grute of the cooler. Rows of stati c grate plates are install ed at the front of the cooler and a layer of cooled <.:linker sits permanently on thi s section of the grate. Fresh hi gh temperature clinker slides over this cooled layer anti hot clinker docs not come into contact with grate. Grate plate wear is signi fi cantly red uced and mechanical reliabi li ty of the cooler is enhanced. Cmm esy: flllemlllional Cement Review, May 1998 These improvements provided by a direct aerated cooler do not mean that there is no rol e for a Spyrometer in such coolers. The moni toring of heat recovery and clinker cooling remains reliant on knowledge of the progression of temperature along the clinker bed in the cooler. This can be provided by Spyrometer or an infra- red scanner. The air flow of the cooler fans and the di stribution of th at ai r can be adjusted to optimise the heat recovery and cooling of the clinker. The visual image from the Spyrometer provides an additional benefit The reliance of di rect aerated coolers on a thick bed of clin ker can lead to problems with snowman formation at the front of the cooler. The visual image from Spyrometer allows the onset of snowman formation to be detected and remedial action to be taken by the operators before interruption of the process becomes necessary. Conclusion In conclusion a Spyrometer installed in a conventional or direct aerated cooler provides a unique combination of visual and temperature information. This allows the efli ciency and reliability of the cooler and kiln system to be significantl y enhanced generating an attracti ve return on investment. 9