---
title: "Collecting electrode"
description: "The collecting electrode — usually called the \"collecting plate\" in plate-type ESPs — is the grounded surface on which charged particulate accumulates inside an electrostatic precipitator. Collecting plates are typically 9–15 m tall, rolled or profiled steel sections with stiffening pockets, hung in parallel rows 250–400 mm apart."
canonical_url: "https://sylio.co/glossary/collecting-electrode"
last_updated: "2026-06-28T02:29:30.330Z"
---

The **collecting electrode** — usually called the "collecting plate" in plate-type ESPs — is the grounded surface on which charged particulate accumulates inside an [electrostatic precipitator](/glossary/electrostatic-precipitator). Collecting plates are typically 9–15 m tall, rolled or profiled steel sections with stiffening pockets, hung in parallel rows 250–400 mm apart.

## How dust accumulates and releases

Charged particles migrate from the [discharge electrode](/glossary/discharge-electrode) towards the grounded plate, transfer their charge and adhere as a dust layer. The layer must be released regularly: too thick and it raises plate-face voltage, reducing the field, eventually triggering [back-corona](/glossary/back-corona). Release is achieved by [rapping](/glossary/esp-rapper) (mechanical impact) or [sonic horns](/glossary/sonic-horn) (acoustic vibration), with the released dust sheet falling into the [hopper](/glossary/esp-hopper) below.

## The re-entrainment problem

Aggressive rapping releases dust faster than the hopper can swallow it, and some of the falling sheet is caught back up by the gas stream — this is [re-entrainment](/glossary/re-entrainment), and it shows up as periodic opacity spikes on stack CEMS traces. Sonic horns produce gentler, more continuous release that reduces re-entrainment compared to mechanical rapping alone.

## Profile types

Collecting plates come in many profiled forms (CW, ZT, ECO, Opzel, baffle, etc.), each chosen to balance electrical performance against dust-release behaviour. Specialist ESP vendors (B&W, FLSmidth, Hamon, Mitsubishi) supply matched plate-and-rapping packages.

## Related terms

- [Electrostatic precipitator](/glossary/electrostatic-precipitator)
- [Discharge electrode](/glossary/discharge-electrode)
- [ESP rapper](/glossary/esp-rapper)
- [Sonic horn](/glossary/sonic-horn)
- [Re-entrainment](/glossary/re-entrainment)