Cyclone Separator Lecture Review

A collection of flashcards based on the lecture transcript regarding Cyclone Separators, covering their mechanisms, advantages, disadvantages, and design equations.

What are the four main classes of particulate control equipment?

Mechanical separators (gravity settlers or cyclones), Fabric filters, Electrostatic precipitators, and Wet scrubbers.

What are the primary advantages of a Cyclone Separator?

Low capital cost, ability to operate at high temperatures, low maintenance (no moving parts), ability to handle mists or dry materials, and relatively small installation space.

What are the main disadvantages of a Cyclone Separator?

Low efficiencies for small particles, high operating costs due to pressure drop, and the inability to process "sticky" materials.

What specific physical forces are used by cyclone separators to remove fine particles?

Centrifugal, gravitational, and inertial forces.

What are the three types of cyclone separators mentioned?

(a) Cyclone with Tangential Entry, (b) Cyclonic Separator, and (c) Axial Entry Cyclone.

What is the formula for the number of effective turns ($N_e$)?

$N_e = \frac{1}{H} \left( L_b + \frac{L_c}{2} \right)$ where $H$ is the height of the inlet duct, $L_b$ is the length of the cyclone body, and $L_c$ is the length of the cyclone cone.

What is the formula for the 50% Cut Diameter ($d_{pc}$)?

$d_{pc} = \sqrt{\frac{9\mu_g W}{2\pi N_e V_i (\rho_p - \rho_g)}}$ where $\mu_g$ is gas viscosity, $W$ is inlet width, $N_e$ is effective turns, $V_i$ is inlet velocity, and $(\rho_p - \rho_g)$ is the density difference.

How is the collection efficiency for the jth particle size range ($n_j$) calculated?

$n_j = \frac{1}{1 + \left( \frac{d_{pc}}{d_{pj}} \right)^2}$ where $d_{pc}$ is the 50% cut diameter and $d_{pj}$ is the characteristic diameter of the jth particle size range.

What is the equation for Penetration ($P_t$)?

$P_t = 1 - n_o$ where $n_o$ is the overall efficiency.

According to the Shepherd and Lapple Equation, how is the number of inlet velocity heads ($H_v$) calculated?

$H_v = K \frac{H W}{D_e^2}$ where $K$ is a constant based on configuration, $H$ is inlet height, $W$ is inlet width, and $D_e$ is gas exit diameter.

What is the formula for the Pressure Drop ($\Delta P$) in a cyclone?

$$\Delta P = \frac{1}{2} \rho_g V_i^2 H_v$$

How does an increase in gas flow rate ($Q$) affect cyclone performance?

Efficiency increases; the relationship is expressed as $\frac{P_{t2}}{P_{t1}} = \left( \frac{Q_1}{Q_2} \right)^{0.5}$.

How does an increase in gas viscosity ($\mu$) affect cyclone performance?

Efficiency decreases; the relationship is expressed as $\frac{P_{t2}}{P_{t1}} = \left( \frac{\mu_2}{\mu_1} \right)^{0.5}$.

What effect does an increase in dust loading ($L$) have on cyclone efficiency?

Efficiency increases; the relationship is expressed as $\frac{P_{t2}}{P_{t1}} = \left( \frac{L_1}{L_2} \right)^{0.18}$.

What is the formula for the work input rate ($W$) into the fluid?

$W = Q \Delta P$ where $Q$ is the flow rate and $\Delta P$ is the pressure drop.