Electric Filter Insulator Chamber Scavenging Gas System

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The increasing cost of electricity for heating scavenging air in electric filters of boiler plants poses a challenge, as existing methods require significant energy expenditure to maintain the required temperature for protecting insulators from dust and condensate.

Innovation Solution

The implementation of a system where process gas from the boiler plant, at a suitable temperature range of 80 to 300 °C, is used as scavenging gas, eliminating the need for separate heating, and incorporating a heating device and valve arrangement to ensure consistent scavenging gas supply during start-up and normal operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate heating is used to heat scavenging air to the required temperature, then the insulator chamber is protected from dust and condensate, but the energy consumption and costs increase significantly

Engineering Contradiction:
Improveprotection of insulatorsVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system uses the boiler plant's own process gas as scavenging gas, making the system self-sufficient. The process gas naturally available at suitable temperatures (80-300°C) eliminates the need for separate heating equipment, reducing energy consumption while maintaining insulator protection

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The process gas from the boiler plant serves dual purposes: it functions as both process gas for the boiler operation and as heated scavenging gas for protecting the insulator chamber. This multi-functionality eliminates the need for dedicated heating systems and reduces overall energy consumption

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Use of energy by moving object

If process gas is used as scavenging gas, then separate heating is eliminated and energy consumption is reduced, but the system complexity increases due to valve arrangements and multiple ducts

Engineering Contradiction:
Improveenergy consumptionVSAvoidsystem complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The first scavenging duct is integrated with the process gas channel of the boiler plant, merging two functions into one system. The valve arrangement combines multiple control functions (switching between process gas and heated air sources, three-way mixing) into a single coordinated control mechanism, reducing overall system complexity despite the additional components

Inventive Principle:
Principle #5Merging (Combining)

3Use of energy by moving object

If process gas temperature is in the range of 80 to 300 °C, then no additional heating is required, but the temperature control flexibility is reduced compared to separate heating systems

Engineering Contradiction:
Improveenergy consumptionVSAvoidtemperature control flexibility
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The system dynamically switches between two scavenging gas sources: process gas during normal operation and heated air during start-up or low-load conditions. The valve arrangement enables real-time adjustment and mixing of gas sources, providing temperature control flexibility while maintaining energy efficiency across different operating conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system prepares for varying operating conditions by having a pre-configured heating device and second scavenging duct ready for use during start-up phases or low-load conditions. This preliminary arrangement ensures that suitable scavenging gas is always available without requiring continuous high energy input

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces energy consumption and costs by utilizing existing process gas as scavenging gas, ensuring effective protection of insulators while minimizing electricity usage, especially during boiler plant start-up phases.

Implementation Method 1

Scavenging air is heated with an electric heater to the required temperature that is 140 °C, for example

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

The insulator chamber of the electric filter is connected through the first scavenging duct to a channel conveying process gas in the boiler plant

Methodology Applied
Scientific EffectGas flow: Convection

Data Source

PatentEP2866940B1Arrangement and method in electric filter
Publication Date: 2016.10.12 VALMET TECH OY
  • EP2866940B1 patent drawingFigure 1
  • EP2866940B1 patent drawingFigure 2

AI summary

An arrangement and method in connection with an electric filter of a boiler plant, the electric filter (1) comprising an insulator chamber (2).The arrangement comprises a first scavenging duct (6) for conveying warm scavenging gas to the insulator chamber (2).Said first scavenging duct (6) is connected to a channel conveying process gas in the boiler plant (5), which means that it is possible to supply process gas to the insulator chamber (2).