Question

Cyclone separator design is based on -

(A) High tangential velocity

(B) Low radial velocity

(C) Low tangential velocity

(D) High radial velocity

Choose the correct answer from the options given below:

• (A) and (C) only
• (A) and (B) only
• (A) and (D) only
• (C) and (D) only

Hint:

Think separately about the spin that throws particles outward and the drift that carries clean air inward.

Answer 1

The Correct Option is B

Step 1: In a cyclone separator, dust laden air enters tangentially and spins around inside the cylindrical body, which creates a strong centrifugal force field acting on the particles.

Step 2: This centrifugal force depends on the square of the tangential (spinning) velocity, so a high tangential velocity is needed to fling the heavier particles hard against the outer wall where they lose momentum and slide down for collection.

Step 3: At the same time, the air still has to work its way inward, toward the central exit tube, and this inward movement is the radial velocity. If the radial velocity is high, particles get swept toward the exit before they have had enough time to migrate outward and hit the wall, so separation efficiency drops.

Step 4: Keeping the radial velocity low gives particles enough residence time inside the spinning stream to reach the wall before the cleaned air exits from the centre.

Step 5: So a good cyclone is designed for high tangential velocity together with low radial velocity, which is (A) and (B) only, option 2.