Scouring Balls Prevent Grid Agglomeration in Fluidized Beds

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Solution Overview

Problem

In fluidized-bed vessels, agglomeration and accumulation on or around the gas distribution grid lead to unstable fluidized beds and frequent shutdowns, causing production delays and increased costs.

Innovation Solution

Introducing scouring balls above the gas distribution grid during the fluidized-bed process to break up and prevent agglomerate formation, using inert, non-fluidizable balls that are laterally movable and designed to minimize disruption to the fluidization process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If scouring balls are introduced into the vessel above the gas distribution grid, then agglomeration and accumulation on the grid is reduced or prevented, but device complexity increases

Engineering Contradiction:
Improvestability of fluidized bed operationVSAvoidcomplexity of vessel contents
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The scouring balls automatically perform the cleaning function through their own lateral movement caused by fluidizing gas flow. The balls self-regulate their position and motion without external control mechanisms, using the process fluid itself to generate the scouring action needed to prevent agglomeration on the grid.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The scouring balls act as intermediary objects between the fluidizing gas and the gas distribution grid. Instead of directly controlling gas flow patterns to prevent agglomeration, the balls mediate this interaction by physically contacting and clearing the grid surface through their lateral movement, simplifying the overall control system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If scouring balls are used to prevent agglomeration, then production continuity is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveproduction continuityVSAvoidease of vessel setup
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The scouring balls are simple, inexpensive objects that can be easily replaced if needed. They are not critical components requiring precision manufacturing, but rather simple spherical objects that perform a mechanical cleaning function, allowing for easy replacement without affecting overall system manufacturing complexity.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If scouring balls are introduced to break up agglomerates, then grid flow blockage is reduced, but fluidization disruption increases

Engineering Contradiction:
Improvegrid flow stabilityVSAvoiduniformity of fluidized bed
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The scouring balls concentrate their cleaning action locally at the gas distribution grid surface where agglomeration occurs. Their lateral movement is specifically directed toward clearing the grid holes and surrounding areas, providing targeted intervention only where needed rather than uniformly affecting the entire fluidized bed.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The scouring balls dynamically adjust their position and movement in response to local variations in gas flow and agglomeration patterns. Rather than being stationary or following a fixed pattern, the balls continuously adapt their motion to the instantaneous conditions at the grid surface, optimizing their cleaning effectiveness while minimizing disruption to the overall fluidized bed structure.

Inventive Principle:
Principle #15Dynamics

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 method effectively reduces and prevents agglomeration and accumulation on the gas distribution grid, maintaining stable fluidized bed operations and reducing the need for frequent vessel shutdowns, thereby minimizing production delays and costs.

Implementation Method 1

In fluidized-bed vessels such as those used in catalytic cracking, gasification, combustion, polymerization, and drying

Methodology Applied
Scientific EffectFluidization: Fluidisation

Implementation Method 2

introducing one or more scouring balls into the vessel above the gas distribution grid; and carrying out a fluidized-bed process in the presence of the scouring balls

Methodology Applied
Scientific EffectGas flow induced lateral movement: Drag

Data Source

PatentEP2247376B1Method of preventing or reducing agglomeration on grid in fluidized-bed vessel
Publication Date: 2018.10.17 WESTLAKE LONGVIEW CORP

AI summary

A method for preventing or reducing agglomeration and/or accumulation on or around the gas distribution grid in a fluidized-bed vessel. The method involves introducing one or more scouring balls into the vessel above the gas distribution grid, and carrying out a fluidized-bed process in the presence of the scouring balls.