calha

Calha is a term used for an elongated groove, trough, or channel designed to guide, collect, or convey liquids or granular materials. In architecture and building, the most common sense is a rain gutter along the edge of a roof, which collects precipitation and directs it toward a downspout. Calhas are often made of metal such as galvanized steel, aluminum, or zinc, or of plastic (PVC), and can be sectional to fit various rooflines. They may have curved or rectangular cross-sections and are lined with coatings to resist corrosion.

In civil engineering and urban drainage, calhas or channels convey surface runoff, stormwater or irrigation water. They can be open channels carved in concrete or lined with concrete, or closed conduits, and are integrated into drainage networks, roadsides, or landscape arrangements. Some calhas are designed for rapid conveyance of large flows, others for sediment control or filtration when paired with gratings or filters.

In industry and mining, calhas act as chutes or troughs that route bulk materials (ores, coal, grains) between equipment. They are typically steel or abrasion-resistant alloys, with smooth interiors and wear liners to extend life and ease cleaning. Some installations use modular plastic liners or fiberglass.

Maintenance and installation considerations include correct slope to promote drainage, secure supports, proper sealing of joints to prevent leaks, and regular cleaning to remove debris. Proper sizing and material selection depend on the intended use, flow rate, and environmental conditions.