Capitol Cement's Project 2000

Abstract

Capitol Cement's dry process line in San Antonio, Texas has recently been upgraded to a nominal clinker production of 1816 mtpd (2000 stpd). The production increase was accomplished by converting the existing in-line calciner to a separate-line down-draft calciner system, retrofitting all preheater stages to a low-pressure design, and making modifications to the existing vertical raw mill. Production and fuel consumption guarantees were met and the system operates with superior performance and reliability. This paper explores Capitol Cement's recent expansion project and identify the relevant system design and start-up issues. Capitol Cement has proved to be a pioneer in implementing emerging technologies, with the end result being that the upgraded dry line is presently one of the most modern kiln lines in the United States. Innovative features such as a down-draft calciner (DDC), a two-channel calciner burner, and a SO/sub 2/ reduction system (D-SO/sub x/) is presented. Interestingly, the SO/sub 2/ reduction system uses a portion of calciner exhaust gas to absorb volatile sulfur compounds from the upper-most preheater stages and thereby prevent their release into the atmosphere. This technology, and others, are presented in the context of the overall project execution.