During backwashing process of a softener tank, resin in the tank is regenerated using brine solution. The Reynolds's number in the tank is needed to be maintained in a range of 4500 to 5500 for effective regeneration process. The internal diameter of the tank is 2 m. Two pipes with 200 mm internal diameter each are installed vertically at top and bottom of the tank with 0.5 m length per pipe. The viscosity and the density of the brine solution are taken as 1.2 mNs/m2 and 1250 kg/m3 respectively. The softener tank is 4 m high and had a friction loss equivalent to 300 pipes diameter;
a) Determine the head loss of the brine solution during backwashing process.
b) If the pump is 80% efficient, calculate the power requirement for the pump during backwashing process.