Spouted-Fluidized Bed Reactor for Polyolefin Fluidization

Solution Overview

Problem

Conventional fluidized bed reactors face challenges in efficiently fluidizing large-diameter polyolefin particles with high cohesion ability, leading to flow defects and increased gas flow rates, which complicates the handling and processing of these particles during molding.

Innovation Solution

The development of a spouted-fluidized bed reactor with a vertically extending cylinder, a decreasing diameter portion, and through holes for gas inlet, allowing for controlled gas flow to create a spouted bed with high gas flow velocity, enabling efficient fluidization of large-diameter polyolefin particles at a lower blowing rate and improving solid-gas contact efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fluidized bed reactors are used to fluidize large-diameter polyolefin particles, then the particles can be processed, but flow defects occur and gas flow rate must be increased

Engineering Contradiction:

Improvefluidization stabilityVSAvoidgas flow rate

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The gas inlet system is segmented into multiple gas inlet orifices distributed across the bottom of the reactor, rather than using a single inlet. This segmentation allows uniform gas distribution across the particle bed, preventing flow defects and enabling stable fluidization of large-diameter particles at lower gas flow rates

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The reactor cross-section is divided into different regions with different numbers of gas inlet orifices - the central region has a different number of orifices compared to the radial region. This local quality variation optimizes gas distribution for large-diameter particles, improving fluidization stability while maintaining low gas flow rates

Inventive Principle:

Principle #3Local quality

2Reliability

If gas flow rate is increased to fluidize large-diameter polyolefin particles, then fluidization is achieved, but pressure loss increases

Engineering Contradiction:

Improvefluidization stabilityVSAvoidpressure loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The gas inlet system is segmented into multiple gas inlet orifices distributed across the bottom of the reactor, rather than using a single inlet. This segmentation allows uniform gas distribution across the particle bed, preventing flow defects and enabling stable fluidization of large-diameter particles at lower gas flow rates

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The reactor cross-section is divided into different regions with different numbers of gas inlet orifices - the central region has a different number of orifices compared to the radial region. This local quality variation optimizes gas distribution for large-diameter particles, improving fluidization stability while maintaining low gas flow rates

Inventive Principle:

Principle #35Parameter changes

3Productivity

If conventional fluidized bed reactors are used for polyolefin production, then production is achieved, but molecular weight distribution and composition uniformity are compromised

Engineering Contradiction:

Improvepolyolefin productionVSAvoidmolecular weight distribution uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The gas inlet system is segmented into multiple gas inlet orifices distributed across the bottom of the reactor, rather than using a single inlet. This segmentation allows uniform gas distribution across the particle bed, preventing flow defects and enabling stable fluidization of large-diameter particles at lower gas flow rates

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The reactor cross-section is divided into different regions with different numbers of gas inlet orifices - the central region has a different number of orifices compared to the radial region. This local quality variation optimizes gas distribution for large-diameter particles, improving fluidization stability while maintaining low gas flow rates

Inventive Principle:

Principle #3Local quality

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 allows for stable fluidization and mixing of large-diameter polyolefin particles at a lower gas flow rate, reducing pressure loss and residence time distribution, and enhancing the production of polyolefins with uniform molecular weight distribution and composition.

Implementation Method 1

a spouted bed or spouted-fluidized bed is formed within a reaction zone

Methodology Applied

Scientific EffectSpouted bed: Fluidisation

Implementation Method 2

allowing for controlled gas flow to create a spouted bed with high gas flow velocity, enabling efficient fluidization

Methodology Applied

Scientific EffectSpouted flow: Turbulence

Data Source

PatentUS8163246B2Spouted-fluidized bed-type olefin polymerization reactor

Publication Date: 2012.04.24 SUMITOMO CHEM CO LTD

AI summary

An olefin polymerization reactor according to the present invention comprises: a vertically extending cylinder; a decreasing diameter portion on the cylinder, having an inside diameter that decreases progressively downward, and having a gas inlet orifice at a bottom end thereof; and a plurality of through holes passing through from an outside surface towards an inside surface of the decreasing diameter portion. Inside a reaction zone enclosed by an inside surface of the decreasing diameter portion and an inside surface above the decreasing diameter portion of the cylinder, a spouted-fluidized bed or a spouted bed is formed.