RESEARCH ON SAPROPEL DEHYDRATION IN A SCREW PRESS WITH A SELF-CLEANING FILTER

Abstract

The formation of sapropel deposits ensures their humidity within 92–98%. To achieve a minimum level of profitability from the use of sapropel, it is necessary to reduce its humidity to 60–70%. Therefore, the process of dewatering the extracted sapropel is the most important stage of processing the extracted deposits. Convective drying, as the most common method of dewatering wet agricultural materials, is very energy-intensive. Among the methods of dewatering materials that involve the use of various kinds of mechanical energy, only cake filtration in presses with a limited chamber volume and the use of gravity during dehydration in pipes made of geotextile materials can be effective for dewatering sapropel. But when using a screw press, the question arises of the effective operation of the filter in which the liquid is separated from the solid. To solve this problem, we have proposed a press design with a self-cleaning filter. Therefore, the purpose of this work is to study the influence of the design parameters of a screw press with a self-cleaning filter on the process of sapropel dehydration. To obtain mathematical models of the studied process in the form of regression equations, the mathematical method of experimental design was applied. Analysis of the obtained equations and graphical dependencies showed that the design of a screw press with a self-cleaning filter is workable and provides a decrease in the humidity of sapropel samples from 92.2% to 80.0-82.0%. It was established that the rational parameters of such a press are the frequency of rotation of the screw shaft rpm, the compression force of the pressure plate spring  N, the gap between the filter rings  mm and the length of the filter  m. With such values, the press productivity will be  kg/s, and the humidity of the dehydrated sapropel - %