The Application of an Expansion Turbine in the Production of Expanded Aggregates

Abstract

The research into the expansion of Cypris clay from the overburden rocks of the Družba brown coal open-pit mine in North Bohemia has proven that targeted expansion enables good use of the thermal energy of hot aggregates, which has not yet been fully exploited. The integration of an electricity production expansion turbine into the production line and the use of residual gas heat in the turbine cycle can reduce production costs. The article assesses two possible solutions for the integration of the expansion turbine into the technological line, namely with an open and closed working cycle using various gaseous media. In both cases, the proportion of the energy usable for electricity generation in the expansion turbine cycle has been calculated along with the possible fuel savings in the rotary kiln by using combustion air preheated to a high temperature by the residual heat of the gas from the turbine gas cycle.