Freeze Drying Sample Line for Continuous Moisture Monitoring

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Solution Overview

Problem

Current freeze-drying processes face challenges in accurately determining the end of the process without interrupting the operation, maintaining sterility, and achieving precise moisture measurement, as existing non-contact methods provide limited value and are not economically viable.

Innovation Solution

A method and system that utilize a sample line to continuously or intermittently remove a small sample of the medium from the freeze-drying system for precise measurement, allowing the process to continue uninterrupted while maintaining sterility, using a vacuum pump and multiple extraction lines aligned with product levels for comprehensive monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If direct measurement on the product is performed, then moisture content measurement is possible, but the freeze-drying process must be interrupted and sterility cannot be maintained

Engineering Contradiction:
Improvemoisture content measurementVSAvoidprocess continuity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The invention extracts a sample of the medium (water vapor) from the freeze-drying chamber through a sampling line and conducts measurement outside the chamber. This allows continuous monitoring without interrupting the freeze-drying process or compromising product sterility, as the measurement occurs in a separate location while the main process continues uninterrupted.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If a spectrometer measures at one point in the chamber, then non-contact measurement is achieved, but only a limited value can be determined and smaller fluctuations cannot be detected

Engineering Contradiction:
Improvenon-contact measurementVSAvoiddetection accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The invention divides the measurement approach by using multiple sampling points within the chamber rather than a single measurement location. This segmentation allows comprehensive monitoring of different regions, improving detection accuracy and enabling the system to capture smaller fluctuations in moisture content across the entire chamber volume.

Inventive Principle:
Principle #1Segmentation

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

Enables precise, continuous monitoring of the freeze-drying process without interrupting the operation, maintaining sterility, and allowing for timely detection of moisture changes, thereby optimizing the freeze-drying process efficiency and accuracy.

Implementation Method 1

part of the medium is removed from the interior of the chamber into a sample line by means of a vacuum pump

Methodology Applied
Scientific EffectVacuum suction: Suction

Implementation Method 2

a condenser (ice trap, cold trap) is connected to the sample line into which the medium flows

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP2447654B1Method for monitoring a freeze drying process and freeze drying system for same
Publication Date: 2018.09.19 HOF SONDERANLAGENBAU GMBH
  • EP2447654B1 patent drawingFigure 1
  • EP2447654B1 patent drawingFigure 2
  • EP2447654B1 patent drawingFigure 3

AI summary

The method involves measuring a medium located in a chamber (10) of a freeze drying system, and removing a portion of the medium continuously from the chamber by using extraction points, which are arranged at storage spaces or at products to be dried. The removed portion of the medium is supplied to a sample line (14), where the measurement of the medium takes place in the sample line. Concentration and/or speed of water vapor formed in the medium are/is measured, where a sample line shutoff valve (12) is arranged in the sample line. An independent claim is also included for a freeze drying system comprising a chamber and a condenser.