Permissible filling level in pipes of gravity water networks with internal deposits

Abstract

Introduction. of the hydraulic characteristics of concrete pipes with a diameter of 400 mm with the values for pipes of the same diameter with different thicknesses of the sediment layer in the flume of the pipes. Materials and methods. Above the flow of waste liquid, the rules for the operation of gravity sewerage networks and current regulations always provide for a free space between the roof of the pipe and the surface of the flow, which ensures ventilation of the network and the transported waste liquid to remove the resulting gases released from the flow. Therefore, the greater the filling value in the pipes Hact, the greater the value of the thickness of the deposit layer h. The calculated dependences derived by the authors for the hydraulic calculation of gravity pipes with internal deposits are used. Results. The existence of a dependence of the actual degree of filling of pipes on the thickness of the layer of deposits in their flume was confirmed. The hydraulic slope values were compared for new concrete pipes and pipes with different thicknesses of the sediment layer in their flume. A specific example is considered, confirming the existence of a dependence of the actual degree of filling of pipes on the thickness of the layer of deposits in their tray part. Measures are indicated that increase the level of operation of sewerage networks from different types of materials. The change in the value of the actual filling level Hact in a gravity pipeline is shown, depending on the thickness of the deposit layer h in its flume part. Conclusions. It is shown that the need for hydrodynamic cleaning of sewerage networks depends on the actual level of their filling. Measures are proposed to ensure an increase in the level of operation of sewerage networks with deposits in the tray part of pipes to meet the requirements of regulatory documents.