Ideally, all particles smaller than the sieve openings pass through the sieve and become the undersize product, while all particles larger than the sieve openings fail to pass through and become the oversize product. This achieves 100% screening efficiency. However, due to various reasons, such as clay and moisture in the raw material causing fine particles that should enter the undersize product to stick to coarse particles and enter the oversize product, or wear and tear on the sieve openings due to prolonged use, coarse particles that should enter the oversize product end up in the undersize product. There are many indicators for evaluating screening efficiency. my country's standard for evaluating the process performance of coal screening equipment (GB/T 15716-2005) specifies screening efficiency, average distribution error, and total mismatch content as evaluation criteria.
Screening efficiency is a technical indicator that evaluates the completeness of the screening process. There are two main indicators for measuring the screening process: production and screening rate.
Productivity: This refers to the amount of material that can be processed per unit of time. The unit is t/h. Screening rate: The ratio of the actual weight of the undersize product obtained during screening to the weight of particles smaller than the screen aperture or sieve opening size in the feed is called screening efficiency, expressed as a percentage. Screening efficiency is an indicator of the working quality of screening equipment. It indicates the degree of screening operation and the quality of the screened product.
The principle for applying the above three indicators is: for the technical appraisal of newly developed equipment, the acceptance of newly commissioned equipment, or important production technology inspections, all three indicators should be used simultaneously for evaluation. This restriction does not apply to routine inspections of screening equipment.
