water flows through a 650mm diameter main with a velocity of 1.5m/sec:?

Question

a) How many kiloliters will pass a given point in one day?

b) If sodium hypochlorite solution conataining 10% available chlorine is being used to chlorinate this main, at what rate (liters/hour) will the sodium hypochlorite be applied to achieve a dose of 1.5mg/L chlorine ?

nedd to see the showing out

Please help

Answer 1

(a)
The volume of water passing per second will be the water contained in a cylinder whose length is the distance covered in 1 sec, i.e. velocity times the cross-sectional area.
Cross-sectional area = PI*(d^2)/4= PI*0.65*0.65/4
= 0.3318 m^2
Volume of water coming out per second is 0.3318*1.5
= 0.4977 m^3 per sec
Now 1 m^3= 10^6 cc = 10^6 ml = 10^3 L = 1 kiloliter
So water flows at the rate of 1 kiloliter per sec.
So water flowing out in a full day is 1*24*60*60
=86400 kiloliter per day.

(b)
Water flows at the rate of 1 kiloliter per sec.
Water flowing out in an hour is 60*60=3600 kiloliter
Chlorine needed per hour is 1.5 mg/L * 3600 kilo liter
=1.5*3600 gm = 5400 gm
Since 10% chlorine is available from the hypochlotite, we need 54000 gm or 54 kg of sodium hypochlorite per hour.

Answer 2

Part A
you will need area of pipe cross section =

∏r² = (650 mm * 1/2 * 1m/1000 mm)² ∏ = (0.325 m)² ∏

(0.325 m)² ∏ * 1.5 m/s * 60 s/min * 60 min/hr * 24 hr/day = 43005.3 m³ / day * 1 Kilo L/ 1 m³ = 43005.3 Kilo Litres / day

B. 43005.3 Kilo Litres/day *1 day / 24 hrs = 1791.89 KL / hr
1.5 mg / L * 1791.89 KL / hr = 2687.84 gm / hr of Cl₂

2687.84 gm of Cl₂/ hr * 10 L Sodium Hypo / 1 gm of Cl₂
26878.4 L Sodium Hypo / hr