Continuous Polymerization Piston System for Gel Drying

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Solution Overview

Problem

Current methods for producing water-soluble dry polymers through continuous operations face challenges in maintaining high molecular weight and 100% solubility due to short residence times in polymerization reactors, leading to residual monomer contamination and quality control issues.

Innovation Solution

A method involving a flow loop that sequentially passes polymerization reagents into a plurality of pistons for controlled polymerization and continuous feeding into a drying step, with coordinated timing and temperature management to prevent premature polymerization and ensure complete filling before reaction initiation, using a stripper tank and inhibitors to delay polymerization until all reagents are present.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If continuous polymerization reaction is used to maintain steady production, then productivity is improved, but manufacturing precision deteriorates due to short residence time making it difficult to maintain high molecular weight and 100% solubility

Engineering Contradiction:
Improvesteady production rateVSAvoidmolecular weight and solubility quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The continuous polymerization process is divided into multiple separate reaction zones (first reaction zone and second reaction zone) with distinct functions. The first zone focuses on rapid polymerization to achieve high conversion, while the second zone provides extended residence time for molecular weight development and solubility optimization, allowing each segment to specialize in specific quality attributes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The monomers are pre-mixed with initiator and other reagents in a feed tank before entering the reaction zones. This preliminary preparation ensures uniform distribution of all components, enabling consistent and controlled polymerization throughout the continuous process, which maintains quality uniformity across steady production.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If continuous polymerization reaction is used to maintain steady production, then productivity is improved, but object-generated harmful factors worsen due to residual monomer contamination

Engineering Contradiction:
Improvesteady production rateVSAvoidresidual monomer contamination
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The polymerization process operates continuously through multiple reaction zones without interruption, ensuring that monomers are completely converted to polymer throughout the extended residence time. The continuous flow through the first and second reaction zones, followed by immediate drying, prevents monomer accumulation and ensures consistent low residual monomer levels in the final product.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The drying step is positioned immediately after the reaction zones to extract and remove any unreacted monomers and water from the polymer product. This rapid extraction prevents residual monomer contamination while maintaining the continuous production flow.

Inventive Principle:
Principle #2Taking out (Extraction)

3Manufacturing precision

If batch processing is used to preserve reliable dry polymer quality, then manufacturing precision is improved, but productivity deteriorates due to less efficient operation

Engineering Contradiction:
Improvepolymer quality reliabilityVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The system dynamically transitions from traditional batch processing to a continuous multi-zone reaction process. The continuous operation with controlled flow rates through multiple reaction zones maintains the quality reliability of batch processing while achieving the production efficiency of continuous operation, effectively combining the advantages of both approaches.

Inventive Principle:
Principle #15Dynamics

4Speed

If wet gels are cut into small pieces for rapid water removal, then drying speed is improved, but device complexity increases due to additional cutting and grinding steps

Engineering Contradiction:
Improvedrying speedVSAvoidcutting and grinding equipment
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The cutting, drying, and grinding operations that were previously separate sequential steps are merged into an integrated continuous drying system. The wet gel enters the drying zone where water is rapidly removed through controlled evaporation, and the dried polymer is simultaneously ground to the desired particle size, eliminating the need for separate cutting and grinding equipment while maintaining high drying speed.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2895530B8Process for preparing water soluble polymers with no insoluble gels and low levels of residual monomers
Publication Date: 2017.09.13 ECOLAB USA INC

AI summary

The invention provides a method and apparatus for continuously feeding wet gel polymers into a drying step of a dry polymer synthesis operation. A number of pistons are arranged having inner chambers through which monomers and other reagents are fed and polymerized into wet gel polymers. Each piston operates according to a coordinated schedule so that as one piston finishes extruding polymer into the drying step, a second piston has completed polymerizing more polymer and continues to feed more polymer without interruption. The then finished is re-fed more reagents so as to be ready again when needed next. As a result, cost effective continuous feeding can be achieved without the contamination and impurity problems that have plagued previous attempts to accomplish this.