Study On Influence Of Number And Spacing Of Drainage Riser,and Transverse Pipe Diameter On System Drainage Capacity

This study is based on the enhanced swirling type special single riser drainage system and the ordinary double riser drainage system with multiple drainage risers into the horizontal pipe.The test system is a 20-layer drainage test device,which using cast iron pipes and fittings.The three influencing factors of the number and the spacing of drainage risers,and the diameter of the transverse pipe are tested.By measuring the system limit pressure and the water seal loss value,the drainage capacity of the system and the measures to improve drainage capacity are obtained under different working conditions.When a plurality of enhanced swirling special single risers convergence,the number of connected risers and the diameter of the transverse pipe have an influence on the water passing capacity of the system,and the spacing of the inlet points has no effect on the water passing capacity of the system: Adopting the enhanced swirling type special single riser drainage system.when the diameter of the horizontal pipe is expanded from DN100 to DN150,the maximum drainage capacity is increased by10% to 11L/s;Adopting the two special single risers convergence system.The diameter of the horizontal pipe is DN150.When the spacing of drainage riser is 1.5m,extended to 3.0m and 6.0m,the water capacity of a single riser is 5L/s,and the total water discharge capacity of the system is 10L/s;The inlet point fitting is DN100×200and the diameter of the horizontal pipe is expanded from DN150 to DN200.When connecting special single riser drainage system,two special single risers convergence system and three special single risers convergence system,the water capacity of a single riser is 10L/s,The total water discharge capacity of the system is increased from 10L/s to 20L/s and then increased to 30L/s;The inlet point fitting is DN150×200 and the diameter of the horizontal pipe is expanded from DN150 to DN200.When connecting special single riser drainage system,two special single risers convergence system and three special single risers convergence system,the water capacity of a single riser is reduced from 10L/s to 9L/s and then to 8L/s.The total water-passing capacity of the system changes from 10L/s to 18L/s and then to 24L/s(due to the increase in the number of drain risers).When multiple ordinary double risers convergence,the number of access risers has an impact on the water passing capacity of the system,while the diameter of thetransverse pipe and the distance between the inlets have no effect on the water capacity of the system: Adopting the ordinary double riser system,when the diameter of the horizontal pipe is expanded from DN100 to DN150,the maximum drainage capacity is still 7.5L/s;Adopting the two ordinary double risers convergence system,when the diameter of the horizontal pipe is DN150,the water capacity of a single riser is 5.5L/s,and the total water discharge capacity of the system is 11L/s,when the diameter of the horizontal pipe is expanded from DN150 to DN200 and the inlet point fitting is DN150 × 200,the spacing of drainage riser is 1.5m to 3.0m and 6.0m,the water capacity of a single riser is 5.5L/s,and the total water discharge capacity of the system is 11L/s,the inlet point fitting is DN100×200,the water capacity of a single riser is reduced from 5.5L/s by 18% to 4.5L/s,and the total water discharge capacity of the system is reduced to 9L/s;When the three ordinary double risers convergence system,when the diameter of the horizontal pipe is DN150 or expanded from DN150 to DN200,the water capacity of a single riser is 5L/s,and the total water discharge capacity of the system is 15L/s.