Drainage pumped system calculation calculation - Option 1 Amount of wastewater to be pumped: 6,72 l/s General data we can know are: Geometrical height Drive height: 9,22 metre. Length of the pipe 22,29 metre. internal pipe diameter: 80 mm. Nº gate valves: 1 Nº valves: 1 Nº 90º elbows: 3 Sump pit calculation Qp = 1,25 · Flow rate
8,4
l/s
Vp = 0,3 Qp (l/s) being Qp pump capacity (l/s) Vp= 2,52 m³
=
2520 Litr Litre e
Note: Starting from the level that results between the ground level to the upper generatrix of the pipe and adding the recommended levels, we obtain the height of the sump pit. With this data we can only calculate the area of it, which results from the formula: litre / height of the pit. Sump pit area = litre/sump pit height Pit heigth = Pit area =
1,91
2,52
m
m² = Pit of
1,79
m of diameter
Sump pit characteris characteristics tics
P´I : 0,91m
PI: 1 m
H= Hr+Pc H: Manometric height (m) Hr: Drive height Pc: Pressure loss (pipes, valves, elbows ...) PI: Immersion depth (m) Sump pit depth: 1,91m Sump pit diameter: 1,80m
Calculation operations of the facility: 2. Pressure loss in Drive: Pipe length: 22,29 metre Singular losses: 10 metre (gate valve) 10 metre (valve) 15 metre (3nº bends of 90 °) Equivalent piping length: 57,29 metre With this value you can get lost in mca across the board losses. That is, 6,72 l/s in a pipe of 80
mm. diameter corresponding to 2,62 metre per 100 linear metre of pipe of given characteristics. Then, 2,62 x 57,29/100 = 1,50 m.c.a Then: Total head = Drive´s pressure loss + Drive heigth = 1.50 + 9,22 = 10,72 mca The appropriate flow rate of the pump must be of 8,4 l/s and the pumping impulse height must be at least of 10,72 m.c.a