6TH INTERNATIONAL ISTANBUL CURRENT SCIENTIFIC RESEARCH CONGRESS
CAPACITY CALCULATION AND OPTIMUM SCREEN DESIGN IN THE MOBILE SCREENING UNIT
Yayıncı:
Liberty Publications
Screening is one of the oldest methods used in history to separate materials of different sizes. Simple sieves that could be carried by hand in the early ages and were moved by human power are now sieves with different geometries and motions found in industrial machines. Motions that will prevent the particles to be screened from remaining fixed in a pile have led to the need to design different screens and drive systems. One of these screen types, the Drum Screen, has a cylindrical geometry and provides mixing and screening of materials by rotating motion. Static and mobile Drum Screen Systems are used in the industry. The geometry and feeding/discharging system of the drum screen used in this study were created in accordance with Mobile Screening Units. The Mobile Screening Unit consists of a drum screen, conveyors that provide feeding and discharging, and an axle system. In this way, it can be pulled to the desired point in the facility or taken to another facility. The factors that determine the performance of the Mobile Screening Unit are; screening capacity and efficiency. Screening capacity is the time between the first feeding and the next feeding and the amount of material screened during this time, while screening efficiency is a measure of how accurately the sieve can separate particles. In this study, the capacity and efficiency of the sieve were measured under different loading conditions and different sieve designs using the Discrete Element Method with the ANSYS Rocky analysis software. Changes in screen designs were made by keeping the minimum dimensions of the holes, total hole areas and screen outer geometries constant. According to the results obtained by analyzing the effect of different hole sizes, improvement studies on the screens were made by changing the pitch distance of the helix part that allows the particles to advance inside the screen. The improved screens were analyzed again and the effect of the improvement was examined. When the results were examined, it was seen that the mass ratio of small and large particles in the feed volume directly affects the screening performance.Increasing the pitch distance is a solution that reduces the sieve efficiency but reduces the reloading time. As the mass ratio of small particles in the pile increases, the effect of the changes made to improve the screening time and efficiency increases.
