Test: Chemical Clarification

Explanation: ‘A’ represents the coagulant pipe which is used for discharging the coagulant into the flash mixer.

Explanation: ‘D’ represents the drain valve which is used for the removal of sludge from the mixer.

Explanation: Temporal mean velocity is the average of velocities at a point over a definite period of time. It is represented by G.

Explanation: ‘B’ represents the outlet of the mixer which goes to the flocculation tank.

Explanation: Temporal mean velocity G = (P/μV) ^1/2, where P is the power, μ is the dynamic viscosity and V is the volume of the tank. It is measured in per second.

Explanation: E represents the Impeller which is driven by the electric motor to revolve in the tank.

Explanation: The speed of impeller in a flash mixer is between 100 to 120 rpm and the propeller type impeller is used.

Explanation: ‘C’ represents the deflecting wall, whereas the boundary below the inlet and outlet of the tank is the flash mixer wall.

Explanation: The detention period of flash mixer lies between 30 seconds to 2 minutes.

Explanation: Impeller is connected to impeller shaft which is further connected to electric motor so as to drive the impeller and mixing of coagulant in water takes place.