sõelad

Sõelad are sieves or strainers used to separate particles by size, allowing finer material to pass through a mesh while retaining larger particles. They consist of a frame that holds a woven or perforated mesh, with the size of the openings determining which particles pass through and which are retained. The term is Estonian for sieve.

Materials and sizes vary widely. Frames are commonly made of stainless steel, carbon steel, aluminum, or durable plastics. Mesh openings are specified by mesh count (holes per inch) or by opening size in micrometres, enabling precise separation in scientific and industrial contexts. In kitchens, common sieves use finer stainless steel meshes, while laboratory and industrial sieves employ standardized sets for reproducible results.

Types and applications. Kitchen sieves and sifters are used to strain liquids, sift flour, rinse grains, or remove lumps from powders. In laboratories, geology, and mining, sieves sort samples according to particle size for analysis and quality control. Construction and civil engineering projects use sieve analysis to determine the grading of aggregates, which influences concrete properties and compaction. Food processing and water treatment also rely on sieves to separate solids from liquids or to separate materials by size during processing.

Operation and care. To use a sieve, place material on the mesh and agitate or shake so smaller particles pass through while larger ones are retained. Clean promptly after use to prevent clogging; dry thoroughly to minimize rust. Regular inspection for damaged frames or torn mesh helps maintain effectiveness and longevity.

See also: sieve, filtration, mesh, sieve analysis.