Trash rake

From Wikipedia, the free encyclopedia

A wooden or metal structure, frequently supported by masonry, that prevents water-borne debris (such as logs, boats, corpses, etc.) from entering the intake of a water mill. This protects wheels, penstocks, and sluice gates from destruction during floods.

Trash rakes composed of vertical wooden strakes separated by narrow gaps are very common and perform extremely poorly. Metal gratings are sturdier and can have narrower strakes, and angling the trash rake properly can allow some self-cleaning from the action of the water. Modern trash rakes such as are used by hydroelectric plants can incorporate such advanced features as wedge-wire screens, the Coanda effect, and cleaning robots.