Cement mfg. plant - with secondary air fed to calciner through the kiln

摘要

Appts. for making cement by the dry method including a rotary kiln, a calcination chamber in front of the kiln, a preheater heated by the effluent gases from the kiln and the calcination chamber and a cooler which provides secondary air to the furnace and the calcination chamber. Specifically the length/dia. ratio of the rotary kiln is 8-12 and the secondary air from the cooler is fed to the calcination chamber through the rotary kiln. Appts. avoids the use of a long heat insulated duct leading from the cooling chamber to the calciner and provision of distributor arrangements to distribute the air between kiln and cooler. Improved heat balance and fuel economy are obtd.