Apparatus and method for ohmic-heating a particulate liquid

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Solution Overview

Problem

Existing ohmic heating methods for particulate liquids face issues with arcing due to air bubbles and empty regions, leading to fouling and unsuitable pasteurization of products like fruit juices.

Innovation Solution

A method involving degassing of the particulate liquid in a vacuum tank with a sprayer creating a flowing film on vertical walls, allowing air bubbles to escape, followed by ohmic heating, and stabilization of liquid flow to prevent arcing through controlled pressure and flow-rate management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If air bubbles are present in the liquid during ohmic heating, then heating can be performed, but arcing occurs which burns particles and creates black spots rendering the pasteurized juice unsuitable

Engineering Contradiction:
Improveheating speedVSAvoidarcing and fouling
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary degassing action before ohmic heating by circulating the liquid through a vacuum chamber where dissolved gases are removed. This preliminary removal of air bubbles prevents arcing during the subsequent heating process, eliminating the harmful effect while maintaining the productivity benefit of rapid ohmic heating.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts air bubbles from the liquid by passing it through a vacuum chamber prior to heating. The vacuum environment causes dissolved gases to come out of solution and be removed from the liquid, thereby eliminating the source of arcing problems before the liquid enters the heating zone.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If regions are not fully filled with liquid during ohmic heating, then heating can proceed, but electric arcs jump through empty regions and calcine particles present in the liquid

Engineering Contradiction:
Improveheating efficiencyVSAvoidprocess stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent ensures continuous liquid flow through the heating zone by maintaining proper flow rates and using flow distribution mechanisms. This continuity prevents the formation of empty regions or gas pockets that would allow arcing, thereby maintaining both heating efficiency and process stability throughout the operation.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent introduces a vacuum chamber as an intermediary step between liquid storage and heating. This intermediary device removes dissolved gases and ensures the liquid is properly degassed before entering the heating zone, preventing arcing issues while maintaining efficient heating.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If conventional heating methods are used for particulate liquids, then equipment complexity is reduced, but heating uniformity is poor and processing time is excessive

Engineering Contradiction:
Improveequipment simplicityVSAvoidheating uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent replaces conventional thermal conduction heating with ohmic heating, where electrical current directly heats the liquid through its resistance. This substitution provides superior heating uniformity and faster processing times while the added complexity is minimized through the use of a relatively simple vacuum chamber for degassing and straightforward electrode placement in the heating zone.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Effectively prevents arcing and fouling by removing air bubbles and maintaining continuous liquid flow, ensuring uniform and efficient pasteurization of particulate liquids.

Implementation Method 1

a vacuum pump (12) for extracting the air floating in said central region

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

said degassing step comprises the substeps of: bringing the liquid into the tank through a sprayer (11)

Methodology Applied
Scientific EffectDegassing:

Implementation Method 3

bringing the liquid into the tank through a sprayer (11) provided with a nozzle (13) arranged for spraying the liquid onto the vertical internal wall

Methodology Applied
Scientific EffectSpray: Spray

Implementation Method 4

heating a conductive liquid by circulating an electric current therein through a pair of electrodes, the conductive liquid being the resistive element which is electrically heated

Methodology Applied
Scientific EffectOhmic heating: Joule Heating

Implementation Method 5

the conductive liquid being the resistive element which is electrically heated

Methodology Applied
Scientific EffectElectrical resistance heating: Joule Heating

Data Source

PatentEP2667111B1Apparatus and method for ohmic-heating a particulate liquid
Publication Date: 2017.07.12 FRUIT TECH NATURAL
  • EP2667111B1 patent drawingFigure 1A~1B

AI summary

Apparatus for the ohmic-heating of a particulate liquid, comprising degassing means (10, 11, 12) for degassing the liquid, which is turn comprises a vacuum tank (10) and at least one sprayer (11), in order to carry out a method comprising the step of degassing the liquid by spraying it onto a vertical or sloping internal wall of a vacuum tank, in such a way that a vertical cylindrical inner region of the vacuum tank that is away from said wall and reaches the top region of the vacuum tank is substantially free of liquid. The apparatus also comprises a conduit (51) for passing the degassed liquid through an ohmic-heating unit (50), a pump (30) located between the vacuum tank and the ohmic-heating unit, a safety valve (21) arranged in parallel with the pump and a back-pressure valve (20) located after the ohmic-heating unit.