Tunnel Pasteurizer Temperature Control for Uniform Zone Treatment

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Solution Overview

Problem

Existing tunnel pasteurizers experience undesirable temperature fluctuations between treatment zones, leading to non-uniform product treatment and reduced quality, while also consuming excessive energy and resources.

Innovation Solution

A method for operating a tunnel pasteurizer that uses actual media temperatures to generate initial values for optimization, coupled with predictive models to determine target media temperatures, ensuring uniform treatment by controlling treatment zones simultaneously during processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If different media temperatures are set in treatment zones to slowly raise and lower container temperature, then pasteurization effectiveness is improved, but temperature fluctuations occur between zones leading to non-uniform treatment

Engineering Contradiction:
Improvepasteurization effectivenessVSAvoidtemperature uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The control device continuously measures actual media temperatures in each treatment zone and compares them with target temperatures. When deviations are detected, the control device automatically adjusts heating and cooling systems to maintain target temperatures, creating a closed-loop feedback control system that prevents temperature fluctuations between zones.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts media temperatures in real-time during container processing based on actual measurements and predictive models. The control device modifies target temperatures and heating/cooling rates adaptively to maintain optimal pasteurization conditions while ensuring uniform temperature distribution across all treatment zones.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If precise control of media temperatures is implemented using control devices, then target media temperatures are maintained, but energy and resource consumption increase

Engineering Contradiction:
Improvemedia temperature controlVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The control device uses predictive models to calculate optimal target media temperatures before processing begins. By pre-determining the exact temperature profile needed for effective pasteurization, the system avoids unnecessary heating and cooling adjustments, reducing energy consumption while maintaining precise temperature control.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system optimizes media temperature parameters dynamically based on actual processing conditions. The control device adjusts heating and cooling rates, media flow rates, and temperature setpoints to match actual container temperature profiles, minimizing energy waste from excessive temperature control while ensuring adequate pasteurization.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If heating and cooling systems are continuously adjusted to maintain target temperatures, then media temperature stability is improved, but treatment time increases

Engineering Contradiction:
Improvemedia temperature stabilityVSAvoidtreatment time
Core Design Contradiction:
Stability of the object's compositionVSDuration of action of moving object

Solution Approach 1:

The control device applies heating and cooling systems with optimized intensity levels that are sufficient to maintain temperature stability without excessive adjustment. By calculating the minimum necessary heating/cooling power required to maintain target temperatures, the system reduces treatment time while ensuring adequate temperature stability for pasteurization.

Inventive Principle:
Principle #16Partial or excessive action

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 ensures more uniform treatment of containers, improves product quality, prevents over-pasteurization, and reduces energy and resource consumption by optimizing media temperatures across zones.

Implementation Method 1

the containers are transported by a conveyor system through several sequentially successive treatment zones, where they are heated and preferably cooled again by treatment media at different temperatures

Methodology Applied
Scientific EffectThermal convection: Convection

Implementation Method 2

the containers are covered with treatment media, in particular water

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

the containers are transported by a conveyor system through several sequentially successive treatment zones, where they are heated and preferably cooled again by treatment media at different temperatures

Methodology Applied
Scientific EffectThermal convection: Convection

Implementation Method 4

the containers are covered with treatment media, in particular water

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3709821B1Tunnel pasteuriser and method for operating a tunnel pasteuriser
Publication Date: 2025.12.31 KRONES AG
  • EP3709821B1 patent drawingFigure 1
  • EP3709821B1 patent drawingFigure 2~3

AI summary

The invention relates to a method for operating a tunnel pasteuriser (1) having a plurality of sequentially successive treatment zones (Z1- Z4), wherein containers (2) with a product packed therein are transported by means of a conveying device (3) through the treatment zones (Z1 - Z4) and in so doing are heated with treatment media having different actual media temperatures, are pasteurised, and preferably then cooled again, wherein the actual media temperatures are detected by a control unit (4) and compared with target media temperatures, and wherein heating and/or cooling units (H1, H2, K3, K4) are controlled based on the comparison, characterised in that during the treatment of the containers (2), initial values for an optimisation (104) are formed (104a) from the actual media temperatures of the treatment zones (Z1 - Z4), and the target media temperatures are determined by means of a prediction model (210) for determining the expected degree of pasteurisation with the optimisation (104), such that at least a minimum degree of pasteurisation of the containers (2) is achieved (104b).