Pre-heating apparatus in rotary kiln plant

Claim 1

Apparatus for pre-heating pulverous raw material used for producing cement or the like in a rotary kiln having a gas outlet end comprising: a. four strings of raw meal treating units, each including a heat exchange zone in which the pulverous material and kiln smoke gases are brought into heat exchange relationship, and a separation zone in which the pulverous material entrained in a smoke gas stream from the kiln is separated from the gas, each string separately communicating with a single through-going substantially vertical smoke gas conduit connected to the gas outlet end of the kiln such that they are disposed independently of the three other strings in a manner which permits independent operation of one or more strings when one or more strings is entirely inoperable from the outlet of the kiln, each string including a plurality of said treating units arranged in series superimposed communicating relationship with respect to each other with said strings being interconnected at the lower portions by material outlet pipes to said single through-going conduit, said strings being arranged substantially vertically and symetrically with respect to a first plane extending vertically through the kiln axis and with respect to a second plane disposed in perpendicular relationship to said first plane adjacent the kiln outlet such that the gas flow and the raw material flow in each string is along independent and substantially similar paths; b. supply means for delivering the pulverous material into each string via the treating unit thereof most remotely located relative to the kiln outlet; and c. means for moving the hot kiln gases through the treating units of each string in a direction countercurrent to the direction of flow of pulverous material therethrough.