1 II. Sewer Networks and Facilities Topic. II. 12. Detention (Retention) Basins: Kinds and Structures. Sewerage Pumping Stations Detention Basins: Kinds I. According to their technological function §For first flush detention §For hydraulic relief of the sewer network §For wet weather regulation of inflow to the WWTP II. According to their position in respect to the sewer main §On the line of the sewer mains §Of line the sewer mains III. According to their structures §Open air detention basins §Underground (covered) detention basins

2 Detention (Retention) Basins: Kinds and Structures Detention Basin on the Main Line with Gravity Emptying: Longitudinal Section (Scheme)

3 Detention (Retention) Basins: Kinds and Structures

4 Screw Pumping Station at the Of Line Detention Basin

5 Detention (Retention) Basins Volume Determination I. Graphical Determination §I - local hydrograph §Hatched area represents the detention volume §Q max /2 - chosen permanent water discharge from the detention basin II. Analytical Determination V = K db.Q max.t o V - detention basin volume K db - detention basin coefficient K db = ,5; ( K db = 0,25 - 0,55) Q max - hydrograph peak t o - time to peak

6 Sewerage Pumping Stations Purpose I. Pumping Stations at the Sewer and Drainage Networks §Rising sewer collector elevation §Transportation of sewage and runoff to higher elevation §Runoff discharge into receiving water II. Pumping Stations at the Wastewater Treatment Plants §Rising wastewater at the WTP inlet §Sludge and wastewater transportation according to the technological requirements §Part of the sludge dewatering equipment

7 Sewerage Pumping Stations (SPS) Schemes Illustrating the SPS Purpose a - Rising sewer collector elevation; б - Wastewater pumping transportation 1 - inlet sewer pipe; 2 - receiving chamber; 3 - machines hall; 4 - gravity sewer collector; 5 - pressure sewer pipe

8 Sewerage Pumping Stations (SPS) Schemes for SPS Structures with Submerged Pumps a - pumps with horizontal axes; б - pumps with vertical axes

9 Schemes for SPS Structures with Non-submerged Pumps Sewerage Pumping Stations (SPS)

10 Sewerage Pumping Stations (SPS) Classical SPS with Horizontal Centrifuge Pumps

11 Sewerage Pumping Stations (SPS) 1 - inlet sewer channels 2 - belt conveyor 3 - bar racks 4 - sluice gates 5 - overhead crane 6 - bridge crane 7 - electrical motor 8 - pumps 9 - barrel for wasted lubricate 10 - pressure pipes 11 - emptying pipe 12 - drainage pump 13 - pipes for suction of sediments 14 - service (water supply) pumps 15 - barrel 16 - service pipe

12 Sewerage Pumping Stations (SPS) SPS with Screw Pumps