Justification of the need for the hydrodynamic cleaning of gravity water discharge networks

Introduction. It is widely known that the operation of sewage treatment facilities requires a significant amount of energy, consumed by the pumping equipment, the automated control system, lighting, heating, ventilation, etc. To ensure the reliable operation of pressure sewerage pipelines, it is necessary to analyze the flow parameters and adequately protect these structures from pressure surges (fluid shocks), that demonstrate unique features in the process of wastewater discharge. The proposed method of analyzing principal hydrodynamic parameters in case of a fluid shock takes into account the multi-phase nature of the pressure flow. The hydrodynamic cleaning of water supply and sewerage networks involves special equipment used to clean pipes, having the diameter of over 150 mm which are made of any material. The process of the hydrodynamic cleaning of networks is expensive and laborious. Therefore, the authors of the article propose to prepare a preliminary justification report for such an expensive operation. The purpose of the research is to identify the pipe characteristics, that can justify the application of the hydraulic method for the removal of a layer of internal deposits. Materials and methods. Dependencies, derived by the authors for the purpose of the hydraulic analysis of gravity drainage networks, are used in the article. Results. Dependence between the actual pipe filling and the thickness of the sediment layer in the pipe gully was confirmed. A specific example is provided by the authors to confirm the existence of such a dependence. The graph shows dependence between the actual pipe filling level and the thickness of the sediment layer in the gully and dependence between the value of the hydraulic slope and the thickness of the actual sediment layer. Conclusions. It is shown that the hydrodynamic cleaning of pipes, having a gully sediment layer exceeding 70 mm, is justified for the case analyzed in the article.