Filters Efficiency Arrestance

Overview

Engineering reference data for Filters Efficiency Arrestance in miscellaneous.

Key Formulas

Unit Conversion

$y = x \cdot k$

Multiply by conversion factor.

Linear Interpolation

$y = y_1 + \frac{(x - x_1)(y_2 - y_1)}{x_2 - x_1}$

Estimate between two known points.

Percentage

$p = \frac{\text{part}}{\text{whole}} \times 100\%$

Part as fraction of whole.

Variables

Symbol	Description	Unit
$x$	Input value	—
$y$	Output value	—
$k$	Conversion factor	—

Particle Sizes

Airborne particles vary significantly in size, affecting their behavior in air streams and the effectiveness of different filtration methods.

Additional Formulas

The text includes two key formulas for calculating filter performance.

Air Filter Efficiency (Atmospheric Dust Spot Efficiency):

$\mu_e = \frac{n_t}{n_u} = \frac{n_u - n_d}{n_u}$

Where:

• $\mu_e$ = air filter efficiency
• $n_t$ = particles trapped
• $n_u$ = particles upstream
• $n_d$ = particles downstream

Dust Arrestance:

$\mu_a = 1 - \frac{C_a}{C_b}$

Where:

• $\mu_a$ = dust arrestance
• $C_a$ = dust concentration after the filter
• $C_b$ = dust concentration before the filter

References

• Original Source