**On what factors ESP efficiency depends
on?**

ESP
efficiency depends on following factors.

- Dust collection area of ESP
- Dust particles size
- Dust or flue gas volume
- Resistivity of dust particles present in flue gas

**What do you mean by Corona Power
ratio?**

Corona power ratio is the ratio of power
consumed in watts to the flue gas flow in cubic feet per minute.

Corona power ratio = Power consumed by ESP in
watts / Flue gas flow in CFM

This tells us about the energy consumed in filtering
one cubic foot of flue gas per minute. The corona power ratio affects the
efficiency of an electrostatic precipitator. Higher the corona power ratio,
higher is the efficiency of the electrostatic precipitator

**What do you mean by specific
collecting area (SCA) & how do you calculate it?**

It is the
ratio of total collecting surface area of the ESP to the flue gas flow rate

SCA = Total
collection area in m2 / Gas flow rate in m3/sec

SCA =
m2/m3/sec

**What do you mean by Aspect ratio in
ESP?**

It is the
ratio of length of ESP to its Height

It should
be in the range of 0.5 to 2

**Calculation: **

**Calculate the aspect ratio of an ESP
of total length 12 meter having its collecting plates height 11 meter.**

Aspect
ratio (AR) = Length of ESP / Height of ESP

Aspect
ratio (AR) = 12/11 =1.09.

**What is the treatment time in ESP
having flue gas flow rate 90 m3/sec at velocity 0.7 m/sec.ESP having total 4
nos of fields each of length 3.5 meter.**

We have,
total length of ESP = 3.5 X 4 = 14 meter

Velocity of
flue gas in ESP = 0.7 m/sec

So, total Treatment
time for flue gas = 14 / 0.7 =20 seconds

*Read power plant O&M reference books*

**An ESP consumes 7 KW power for treating
flue gas of 17 m3/sec, calculate its Corona power ratio.**

Corona power ratio = Power consumed by ESP in
watts / Flue gas flow in CFM

We have
flue gas flow = 17 m3/sec = 599.9 X 60= 35994 CFM

CPR = 7000
/ 35994 = 0.2

**An ESP handles total flue gas at the
rate of 61920 m3 /h., its specific collecting surface area is 131.9 m2/m3/sec,
calculate the efficiency of ESP if ash particles migration velocity is 5.46 cm/sec.**

Given
that,

Flue
gas flow in ESP, Q = 61920 m3/hr / 3600 = 17.2 m3/sec

Total
collecting area A= 131.9 X 17.2 =2268.68 m2

Migration
velocity of dust particles, V = 5.46/100 = 0.0546 m/sec

Efficiency
of ESP = 1–eˆ (-AV/Q) X 100

= 1– eˆ (-2268.68 X 0.0546/17.2) X 100

ηESP = 99.92%

** Read more>>> for such calculations powerplant & Calculations**

*ESP troubleshooting guide*