Polymerization Reactor Design for Droplet Control and Wall Deposit Prevention

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Solution Overview

Problem

Existing droplet polymerization processes for producing poly(meth)acrylate face issues with deposit formation due to droplets colliding with reactor walls and increased energy consumption when scaling up to industrial levels.

Innovation Solution

A reactor design with a conical expansion above the fluidized bed, positioned gas extraction points, and a device for dripping the monomer solution through holes that ensure droplets fall vertically into the fluidized bed, minimizing wall contact and optimizing gas flow to prevent particle entrainment, while maintaining a larger hydraulic diameter between the droplet formation and gas extraction points.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If droplet polymerization is performed in a conventional reactor, then polymer particles are produced, but deposit formation occurs on reactor walls due to droplet collision

Engineering Contradiction:
Improvepolymer particle productionVSAvoiddeposit formation
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The reactor is divided into multiple functional zones: a droplet formation zone with a specific device having holes for monomer solution introduction, a reaction zone, and a separation zone with a fluidized bed. This segmentation ensures droplets form in a controlled manner and fall vertically into the fluidized bed, preventing wall contact and deposit formation while maintaining production efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A gas stream is introduced as an intermediary medium between the droplet formation device and the reactor wall. The gas extraction points positioned on the peripheral wall create a gas flow that acts as a protective barrier, preventing droplets from contacting and adhering to the reactor wall, thus eliminating deposit formation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the reactor is scaled up to industrial standards, then production capacity increases, but energy consumption increases sharply

Engineering Contradiction:
Improveproduction capacityVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The reactor design optimizes geometric parameters including the hydraulic diameter ratio (at least 10% larger between droplet formation and gas extraction levels), conical expansion angle, and positioning of the droplet formation device. These parameter optimizations enable efficient droplet guidance and gas flow management that maintain low energy consumption even at large industrial scales.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system utilizes pneumatic principles by introducing gas through addition points and extracting it at peripheral points to create controlled gas flows. This pneumatic system guides droplets vertically into the fluidized bed and prevents wall contact, achieving scalable production with optimized energy efficiency through gas-dynamic control rather than mechanical means.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Productivity

If droplets are allowed to fall freely into the fluidized bed, then reaction efficiency is maintained, but particle entrainment with exhaust gas occurs

Engineering Contradiction:
Improvereaction efficiencyVSAvoidparticle loss
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The reactor incorporates a conical expansion section that adds a vertical dimension to the gas flow path. The gas extraction points are positioned on the peripheral wall of this conical section, creating a radial-outward gas flow that separates particles from the vertical exhaust stream, preventing particle entrainment while maintaining efficient droplet fall into the fluidized bed.

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

Solution Approach 2:

The design allows droplets to rapidly fall through the gas phase into the fluidized bed before gas extraction occurs. The gas is extracted at a level below the droplet formation device but above the fluidized bed, creating a separation zone where particles are given time to settle into the fluidized bed before being carried by the exhaust gas, thus preventing particle loss.

Inventive Principle:
Principle #21Skipping (Rushing through)

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 design significantly reduces deposit formation and energy consumption by ensuring only non-sticky droplets reach the wall and prevents particle loss with the exhaust gas, enhancing the efficiency and scalability of the polymerization process.

Implementation Method 1

The mechanism of droplet formation can be turbulent or laminar jet breakup or droplet formation

Methodology Applied
Scientific EffectTurbulent jet breakup: Turbulence

Implementation Method 2

The mechanism of droplet formation can be turbulent or laminar jet breakup or droplet formation

Methodology Applied
Scientific EffectLaminar jet breakup: Laminar Flow

Implementation Method 3

The mechanism of droplet formation can be turbulent or laminar jet breakup or droplet formation

Methodology Applied
Scientific EffectDroplet formation:

Implementation Method 4

The droplets fall down in the reactor, where the monomer reacts to form the polymer. In the lower area of the reactor there is a fluidized bed, into which the polymer particles formed from the droplets by the reaction fall

Methodology Applied
Scientific EffectGravitational settling: Gravitation

Implementation Method 5

In the lower area of the reactor there is a fluidized bed, into which the polymer particles formed from the droplets by the reaction fall

Methodology Applied
Scientific EffectFluidization: Fluidisation

Data Source

PatentEP3157962B1Apparatus for production of pulverulent poly(METH)acrylate
Publication Date: 2019.04.10 BASF SE
  • EP3157962B1 patent drawingFigure 1
  • EP3157962B1 patent drawingFigure 2~3
  • EP3157962B1 patent drawingFigure 4~5

AI summary

The invention relates to an apparatus for production of pulverulent poly(meth)acrylate, comprising a reactor (1) for droplet polymerization having an apparatus for dropletization (5) of a monomer solution for the production of the poly(meth)acrylate having holes through which the solution is dropletized, an addition point for a gas (13) above the apparatus for dropletization (5), at least one gas withdrawal point (19) on the circumference of the reactor (1) and a fluidized bed (11). The outermost holes through which the solution is dropletized are positioned in such a way that a droplet falling vertically downward falls into the fluidized bed (11), and the hydraulic diameter at the level of the midpoint between the apparatus for dropletization (5) and the gas withdrawal point (19) is at least 10% greater than the hydraulic diameter of the fluidized bed (11).