Helical Stirrer for Uniform Pasteurization of Liquid Food

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Solution Overview

Problem

Existing pasteurizing machines face challenges in uniformly regulating the temperature of liquid or semi-liquid food products, leading to localized burning or overheating, which affects the quality and organoleptic properties of the processed products.

Innovation Solution

A machine comprising a first container for thermal treatment, a second container for feeding the product, a stirrer for mixing, and a thermodynamic system with a heat exchanger, compressor, and pressure reducing unit, allowing for uniform heating and cooling by controlling the temperature between 50°C and 85°C, and enabling the product to be heated progressively through recirculation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the product is heated near the heated walls of the container, then the thermal treatment efficiency is improved, but localized burning or overheating occurs which modifies the quality of the product

Engineering Contradiction:
Improvethermal treatment efficiencyVSAvoidtemperature uniformity
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The patent employs a dynamic stirring mechanism that continuously moves the product within the container, transforming the static heating process into a dynamic one. This ensures that different portions of the product are exposed to heated walls at different times, preventing localized overheating while maintaining thermal treatment efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The stirring mechanism acts as an intermediary between the heated walls and the product, mediating the heat transfer process. By introducing this intermediate element, the direct contact between product and heated walls is controlled and distributed, preventing localized burning while ensuring uniform thermal treatment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the product is heated to achieve pasteurization, then the preventive pasteurization effect is improved, but localized burning or overheating occurs which affects organoleptic properties

Engineering Contradiction:
Improvepasteurization effectivenessVSAvoidlocalized burning
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The continuous stirring creates dynamic movement of product layers, ensuring that no single layer remains in contact with heated walls for extended periods. This dynamic approach maintains pasteurization effectiveness by ensuring all product receives adequate heat while preventing harmful localized burning.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The stirring mechanism operates continuously throughout the heating process, ensuring uninterrupted mixing and heat distribution. This continuous action prevents localized overheating while maintaining consistent pasteurization throughout the product volume.

Inventive Principle:
Principle #20Continuity of useful action

3Speed

If the thermal power is increased to speed up heating, then the heating speed is improved, but temperature control precision deteriorates leading to overheating

Engineering Contradiction:
Improveheating speedVSAvoidtemperature control precision
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The dynamic stirring system allows for high thermal power input while maintaining temperature control precision. The continuous movement distributes heat rapidly throughout the product, preventing localized overheating even when high thermal power is applied, thus enabling both fast heating and precise temperature control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The continuous stirring action ensures that heat is constantly redistributed throughout the product volume, allowing for higher thermal power input without sacrificing temperature control. The uninterrupted mixing prevents temperature gradients from developing, maintaining precision even at higher heating rates.

Inventive Principle:
Principle #20Continuity of useful 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

Ensures uniform thermal treatment of products, preventing localized heating and improving the quality by maintaining the product in motion during pasteurization, allowing for precise temperature control through adjustable stirrer speed without altering thermal power.

Implementation Method 1

a thermal system (5) comprising a heat exchanger (6) associated with the walls of the first processing container (2) to release heat to the first processing container (2)

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

heating the walls of the first processing container (2) to a temperature between 50°C and 85°C

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

making the stirrer (4) rotate in such a way as to cause the liquid or semi-liquid product to advance continuously from the inlet end (35) to the outlet end (36) of the stirrer (4)

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

a thermal system (5) comprising a heat exchanger (6), a further heat exchanger (30), a compressor (31), and a pressure reducing unit (32)

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3718409B1Machine and method for thermally treating liquid or semi-liquid food products
Publication Date: 2024.09.11 ALI SPA CARPIGIANI GRP
  • EP3718409B1 patent drawingFigure 1
  • EP3718409B1 patent drawingFigure 2~3
  • EP3718409B1 patent drawingFigure 4

AI summary

Described is a machine (1) for pasteurizing liquid or semi-liquid food products, comprising: - a first container (2) for the thermal treatment of a liquid or semi-liquid base product; - a second container (3) for feeding the liquid or semi-liquid base product, connected to the first, thermal treatment container (2), for feeding the liquid or semi-liquid base product; - a stirrer (4) for mixing the product in the first, processing container (2) and mounted inside the first, thermal treatment container (2); - a thermal system comprising an exchanger (6) associated with the walls of the first, processing container (2) and configured to release heat at the walls of the first, thermal treatment container (2), the machine being characterized in that the stirrer (4) is externally helically shaped and extends between a first, inlet end and a second, outlet end, so that as it rotates, the liquid or semi-liquid product is made to advance between the first, inlet end (35) and the second, outlet end (36). [Figure 1]