Improving the Efficiency of Equipment and Technology of Waste Briquetting

Abstract

The present-day problem of the accumulation of carbon waste was considered in connection with the aggravating urgency. General tendencies and approximate rational compositions of unprepared polydisperse fractions of mixtures of potential raw materials during their compaction and subsequent thermolysis have been experimentally determined. It was found that with an increase in moisture or binder content, solid carbon waste becomes more plastic and viscous (from 0.6 to 0.4), the coefficient of internal friction decreases. The effect of moisture on the coefficient of external friction is less noticeable (up to a 25 % reduction). It has been determined that preheating of the charge to 80 °C contributes to a decrease in density of the resulting briquettes (on average by 5–6 %) and leads to an increase in the coefficient of elastic expansion. Briquettes, all other things being equal, are 5–10 % stronger but a 1 % increase in strength accounts for a 2 % increase in energy costs. Upon re-compaction, a noticeable change in compression properties occurs. The briquette density increases by an average of 7 %. With a lower binder content, a 14 % increase in density was obtained. In this case, the increase in strength is directly proportional to energy consumption. An increase in binder content in briquets and their re-compaction were recommended. It has been found that with the optimized operation of the boiler plants that incinerate the briquetted waste, the coefficient of expenditure per year is 32.9 % less than the value of this index when using the equipment for recovery of unprepared waste. At the same time, the coefficient of influence on the environment over a 15-year period was 28.89 % less than the value of this index when operating similar equipment. The results obtained reasonably indicate that the optimized technology of waste briquetting and subsequent incineration is characterized by a significant increase in the environmental and economic efficiency of the waste recovery process.