Municipal drainage system with reduced liquid level - involves minimum outlay of materials while avoiding deposits in sewers

摘要

The municipal drainage system for conveying liquid with entrained solids is operated at reduced liquid level by reducing the flow cross-section of the sewer by an air cushion. The cross-section may be reduced over the whole length of the pipe, or variably in sections according to the gradient and the location of supply. The air cushion may be replaced by other gases or gas mixtures, and is provided by installing hermetically and pressure-tightly connected partitions at both ends of the horizontal pipe section and in the ascending pipe section.