USA-EPA – LESSON 3 ESP Design Parameters and Their Effects on Collection Efficiency

LEVCentral Expert Commentary

Electrostatic Precipitators (ESPs) are capable of achieving collection efficiencies in excess of 99%, but this level of performance is only possible when the precipitator has been correctly designed for its specific application.

This EPA training lesson examines the engineering parameters that influence ESP performance and explains how manufacturers determine the size, configuration and operating characteristics of a precipitator. It introduces concepts such as migration velocity, particle resistivity, specific collecting area, aspect ratio, gas flow distribution and corona power, demonstrating how each contributes to overall collection efficiency.

The lesson also explains that ESP design is not based on a single equation or rule of thumb. Instead, designers combine theoretical calculations with practical experience, pilot testing and computer modelling to produce a system capable of achieving the required emission limits under real operating conditions.

Although intended for environmental engineers reviewing pollution control equipment, the principles described remain highly relevant to anyone specifying, designing or assessing electrostatic precipitators used within industrial ventilation and emission control systems.

View Source Document

View Lesson 3

Source: USA EPA
Document Type: Technical Lesson
Status: Current 1985
Last reviewed by LEVCentral: June 2026

Key Learning Points

How collection efficiency is estimated during ESP design.
The significance of particle migration velocity.
Differences between theoretical and effective collection efficiency.
The influence of dust resistivity on ESP performance.
Methods for overcoming high and low resistivity problems.
The importance of electrical sectionalisation.
Understanding corona power and its influence on particle charging.
The role of specific collecting area (SCA) in determining collector size.
Why aspect ratio influences collection performance.
The importance of uniform gas flow distribution throughout the precipitator.
Practical design methods used by ESP manufacturers.

LEVCentral Perspective

One of the strengths of this lesson is that it explains why ESP performance depends upon far more than simply increasing collecting plate area.

Particle charging efficiency, electrical field strength, gas velocity, particle resistivity and gas distribution all interact to determine the final collection efficiency. Optimising one parameter may have little effect unless the others are also considered.

For LEV engineers, this reinforces an important engineering principle that applies equally to other air pollution control equipment: successful performance depends upon balancing multiple design variables rather than maximising any single parameter. Understanding these relationships enables designers to specify systems that achieve reliable long-term performance under real operating conditions.

Further Resources

Recommended Learning

Thought Leadership

Modern electrostatic precipitators demonstrate that high-performance air pollution control is achieved through careful engineering rather than simply increasing equipment size. The relationships between migration velocity, resistivity, electrical energisation and gas flow illustrate how multiple design parameters combine to determine collection efficiency.

Although modern design increasingly relies on sophisticated computer modelling, the engineering principles explained in this lesson remain fundamental.

Understanding these concepts enables engineers to critically evaluate ESP performance, interpret manufacturer data and appreciate why apparently similar precipitators can perform very differently under changing process conditions.