Continuous Drum Dryer for Slurry Drying

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Solution Overview

Problem

Current pharmaceutical manufacturing processes, particularly batch manufacturing, face inefficiencies such as long lead times, large footprints, and quality control challenges due to the use of conventional dryers that are not compatible with continuous production methods, leading to product degradation and contamination risks.

Innovation Solution

A continuous drying apparatus featuring a pair of rotatable drums with an adjustable gap, conductive heating, and operation under reduced pressure, allowing for real-time control of drying parameters and efficient processing of slurries with minimal residence time, enabling the production of dried solids with defined residual moisture content.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional batch dryers are used for drying slurries, then the drying process can be completed, but the residence time is extended (>12 hours) resulting in product degradation and agglomeration

Engineering Contradiction:
Improveproduct qualityVSAvoidresidence time
Core Design Contradiction:
Manufacturing precisionVSDuration of action of moving object

Solution Approach 1:

The patent implements a continuous drying process where slurry is continuously fed onto the rotating heated drum surface and dried product is continuously removed by scrapers. This eliminates the batch-wise loading and unloading of conventional dryers, maintaining continuous drying action that reduces residence time from over 12 hours to minutes, thereby preventing product degradation and agglomeration while maintaining drying effectiveness

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent applies a coating or pre-treatment to the drum surface that facilitates controlled drying and prevents premature agglomeration before the drying cycle completes. The drum surface is prepared in advance with appropriate properties (heat distribution, surface texture) to ensure uniform drying from the moment slurry contact occurs, avoiding the degradation that happens during extended batch processing

Inventive Principle:
Principle #10Preliminary action

2Productivity

If conventional batch dryers are used, then drying can be performed, but the manufacturing footprint is large and incompatible with continuous production systems

Engineering Contradiction:
Improvecontinuous production capabilityVSAvoidmanufacturing footprint
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent divides the drying function into modular components: a rotating drum assembly with heated surface, scraper mechanisms for product removal, and a compact housing. This segmentation allows the dryer to be integrated as a single module into continuous production lines, reducing the overall footprint compared to large batch dryer installations while maintaining continuous operation capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from the two-dimensional batch processing mode (loading/unloading from large chambers) to a three-dimensional continuous flow system where material moves through the drying zone in a controlled path along the rotating drum. This dimensional change enables compact integration into production lines with significantly reduced floor space requirements while achieving continuous throughput

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

3Object-affected harmful factors

If batch drying processes are used, then drying can be completed, but personnel exposure to hazardous substances increases and contamination risk rises

Engineering Contradiction:
Improvepersonnel safety and contamination riskVSAvoidautomated continuous operation
Core Design Contradiction:
Object-affected harmful factorsVSExtent of automation

Solution Approach 1:

The patent designs the continuous dryer as a self-contained automated system with enclosed housing, automatic slurry feeding mechanisms, and automated product removal via scrapers. The system operates without human intervention during the drying cycle, eliminating personnel exposure to hazardous substances and contamination risks associated with manual batch loading and unloading operations

Inventive Principle:
Principle #25Self-service

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 apparatus significantly reduces product degradation and agglomeration, enhances safety and sustainability by recovering liquids, and integrates seamlessly into continuous manufacturing systems, improving the efficiency and quality of pharmaceutical production.

Implementation Method 1

heating the pair of rotatable drums to a first temperature

Methodology Applied
Scientific EffectConductive heating: Conduction (thermal)

Implementation Method 2

drying the slurry to produce a cake and an evaporate

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

a housing capable of operation at a reduced pressure

Methodology Applied
Scientific EffectReduced pressure: Vacuum

Data Source

PatentEP3411126B1Continuous drum dryer and methods of use thereof
Publication Date: 2021.03.24 CONTINUUS PHARMACEUTICALS INC
  • EP3411126B1 patent drawingFigure 1
  • EP3411126B1 patent drawingFigure 2
  • EP3411126B1 patent drawingFigure 3

AI summary

The present disclosure provides for a continuous drying apparatus and a method of using the apparatus in the preparation of dried solids from slurries. The methods and apparatus are useful for the production of fine chemicals and pharmaceuticals, particularly using Integrated Continuous Manufacturing (ICM), but can also be integrated with other manufacturing processes, such as batch and semi-continuous processes.