Stepped Flow Control Grid for Uniform SCR Flue Gas Turning

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Solution Overview

Problem

Existing flow control grids for SCR systems are large, heavy, and costly due to the difficulty in controlling flue gas velocity and direction, leading to premature catalyst deterioration and increased height, which complicates installation and increases costs.

Innovation Solution

A compact flow control grid with a flow straightening section and a flow turning section featuring a plurality of channel assemblies and turning vanes that change the direction of fluid flow by 90 degrees, creating a uniform velocity profile across the outlet, utilizing a stepped configuration and specific angles to optimize flow distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional flow control apparatuses are used to change flue gas direction and establish uniform velocity profile, then flow control function is achieved, but the apparatus becomes large, heavy, and costly

Engineering Contradiction:
Improveflow control functionVSAvoidapparatus weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The flow control grid is divided into multiple channel assemblies (e.g., 16 channel assemblies) that are arranged in a compact configuration. Each channel assembly contains turning vanes and flow straightening elements that work together to control flow locally, achieving overall flow control in a compact structure that reduces weight compared to conventional large-scale apparatuses.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses a three-dimensional stepped configuration where channel assemblies are arranged at different heights and positions within the grid structure. This spatial arrangement allows effective flow control in a compact volume, reducing the overall apparatus size and weight while maintaining the flow control function.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If conventional flow control apparatuses are used to change flue gas direction and establish uniform velocity profile, then flow control function is achieved, but the apparatus height increases significantly

Engineering Contradiction:
Improveflow control functionVSAvoidapparatus height
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The grid is segmented into multiple channel assemblies arranged in a compact three-dimensional configuration rather than a single large structure. This segmentation allows the flow control function to be achieved in a reduced height by distributing the flow control elements across multiple compact units.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The channel assemblies are arranged in a stepped three-dimensional configuration that utilizes horizontal and vertical space efficiently. This dimensional arrangement achieves effective flow control without requiring significant height, as the flow control functions are distributed across multiple levels and positions within a compact volume.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Speed

If flue gas velocity is not controlled properly, then flow direction change is achieved, but catalyst deterioration occurs due to localized high velocities

Engineering Contradiction:
Improveflow direction changeVSAvoidcatalyst durability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

Each channel assembly is equipped with turning vanes and flow straightening elements that locally control the flue gas velocity and direction. This local control ensures that high velocities are distributed evenly across all channel assemblies rather than concentrating in specific areas, preventing localized catalyst erosion while maintaining effective flow direction change.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The multiple channel assemblies are designed with similar configurations and are arranged to create a uniform velocity profile across the grid outlet. This homogeneity in flow distribution ensures that catalyst exposure to high velocities is evenly distributed, preventing localized deterioration and extending catalyst life.

Inventive Principle:
Principle #33Homogeneity

4Weight of stationary object

If compact flow control grid is designed, then apparatus size and cost are reduced, but flow control effectiveness must be maintained

Engineering Contradiction:
Improveapparatus weightVSAvoidflow control effectiveness
Core Design Contradiction:
Weight of stationary objectVSReliability

Solution Approach 1:

The compact grid is segmented into multiple channel assemblies, each containing turning vanes and flow straightening elements. This segmentation allows effective flow control to be achieved in a compact structure by distributing the control function across multiple smaller units rather than requiring a single large apparatus.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The channel assemblies are arranged in a three-dimensional stepped configuration that maximizes flow control effectiveness within a compact volume. This spatial arrangement allows the compact grid to achieve the same flow control effectiveness as larger conventional apparatuses by utilizing vertical and horizontal space efficiently.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

The solution reduces SCR reactor height, minimizes erosion, and enhances catalyst efficiency by achieving a uniform flow velocity profile, resulting in cost savings and improved system performance.

Implementation Method 1

a flow turning section having a plurality of turning vanes which extend into and cooperate with the flow straightening section to cause a change in direction of fluid flow

Methodology Applied
Scientific EffectFluid flow direction change:

Implementation Method 2

develop a uniform flow velocity profile across an outlet of the flow control grid

Methodology Applied
Scientific EffectFlow velocity uniformization:

Data Source

PatentEP2666535B1Flow control grid
Publication Date: 2022.06.08 ANDRITZ AB
  • EP2666535B1 patent drawingFigure 1
  • EP2666535B1 patent drawingFigure 2
  • EP2666535B1 patent drawingFigure 3

AI summary

A flow control grid includes a plurality of channel assemblies connected to one another. Each of the plurality of channel assemblies defines a flow straightening section and a flow turning section. The flow turning section has an arcuate segment and a first substantially flat segment. The first substantially flat segment is positioned in the flow straightening section. The arcuate segment extends outwardly from the flow straightening section.