Lactose Crystallization Yield via Evaporator System Segmentation

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Solution Overview

Problem

Existing methods for producing crystallized lactose suffer from low yield and efficiency due to issues with input quality, deposition, viscosity, heat transfer efficiency, crystal size distribution, and loss of fines, leading to suboptimal crystallization processes.

Innovation Solution

A method involving a lactose-containing liquid with less than 80% total solids, utilizing a heat exchanger and evaporation vessel with a rising film or flooded tube heat exchanger for forced circulation, allowing controlled crystallization and recirculation to achieve high solids content and consistent crystal size, followed by classification using a hydrocyclone for enhanced yield and purity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional crystallization methods are used, then the process is simple, but the yield is low and efficiency is poor

Engineering Contradiction:
Improveyield of crystallized lactoseVSAvoidcrystallization system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The crystallization system is divided into separate functional modules: a heat exchanger for heating and concentration, an evaporation vessel for controlled evaporation and crystal growth, and a hydrocyclone for separation. This segmentation allows each component to be optimized for its specific function, improving overall yield while maintaining manageable complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A hydrocyclone is introduced as an intermediary separation device between the evaporation vessel and the final product. The hydrocyclone uses centrifugal force to separate lactose crystals from the mother liquor, enabling efficient solid-liquid separation without requiring complex filtration or centrifugation systems, thus improving yield while keeping the system practically manageable

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If heating temperature is increased to improve heat transfer efficiency, then heat transfer efficiency improves, but lactose degradation and loss increase

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidlactose loss
Core Design Contradiction:
PowerVSLoss of substance

Solution Approach 1:

The system optimizes heat transfer by controlling the heating temperature within a specific range (50-90°C) rather than using high temperatures. The heat exchanger design and residence time are adjusted to achieve sufficient heat transfer efficiency at these moderate temperatures, preventing lactose degradation while maintaining effective heat transfer

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The lactose solution undergoes continuous circulation through the heat exchanger and evaporation vessel, maintaining constant heat transfer surface contact. This continuous flow ensures efficient heat transfer over time without requiring high instantaneous temperatures, thereby improving heat transfer efficiency while minimizing lactose loss through controlled, sustained heating

Inventive Principle:
Principle #20Continuity of useful action

3Productivity

If the lactose solution is concentrated to high solids content, then crystallization yield improves, but viscosity increases and heat transfer decreases

Engineering Contradiction:
Improvecrystallization yieldVSAvoidheat transfer efficiency
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The system performs preliminary concentration of the lactose solution in the evaporation vessel before the final crystallization stage. By pre-concentrating the solution to an optimal solids content (58-80%), the system prepares the solution for efficient crystallization while avoiding excessive viscosity that would impede heat transfer. This preliminary concentration action allows the final crystallization to proceed with better heat transfer efficiency

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the solids content of the lactose solution during the crystallization process. The continuous circulation and evaporation allow real-time control of concentration levels, maintaining the solution within the optimal viscosity range for heat transfer while achieving high crystallization yield. This dynamic control prevents the solution from becoming too viscous, thereby maintaining heat transfer efficiency throughout the process

Inventive Principle:
Principle #15Dynamics

4Manufacturing precision

If crystallization time is extended to improve crystal size distribution, then crystal uniformity improves, but production time increases

Engineering Contradiction:
Improvecrystal size distributionVSAvoidcrystallization process time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The crystallization process operates continuously with the lactose solution circulating through the heat exchanger and evaporation vessel without interruption. This continuous action maintains consistent supersaturation levels and crystal growth conditions, producing uniform crystal size distribution while avoiding the time losses associated with batch processing and repeated heating cycles

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system controls crystal growth by maintaining specific temperature and supersaturation parameters throughout the crystallization process. The heat exchanger keeps the solution at controlled temperatures (50-90°C), and the evaporation rate is regulated to maintain optimal supersaturation, enabling uniform crystal growth within a reasonable time frame without requiring extended processing

Inventive Principle:
Principle #35Parameter changes

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 method increases the yield of crystallized lactose from 60% to 70-80% by weight, reduces lactose loss in the mother liquor, and produces crystals with consistent size distribution, facilitating better downstream processing and reducing the frequency of cleaning requirements.

Implementation Method 1

heating the lactose-containing liquid in the heat exchanger to 50 to 90° C such that the lactose-containing liquid passes along the flowpath by forced circulation or thermo-siphoning

Methodology Applied
Scientific EffectForced circulation: Forced Convection

Implementation Method 2

heating the lactose-containing liquid in the heat exchanger to 50 to 90° C such that the lactose-containing liquid passes along the flowpath by forced circulation or thermo-siphoning

Methodology Applied
Scientific EffectThermo-siphoning: Free Convection

Implementation Method 3

concentrating the lactose-containing liquid in the evaporation vessel, to generate crystallised lactose in the lactose-containing liquid in the evaporator system

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

Crystallisation of a lactose solution produces crystals of α-lactose monohydrate (ALM). As ALM crystals are formed β-lactose coverts to α-lactose in the solution to maintain the equilibrium between these two isomers

Methodology Applied
Scientific EffectCrystallisation: Crystallisation

Data Source

PatentEP2629623B1Lactose production
Publication Date: 2018.03.21 FONTERRA COOP GRP LTD
  • EP2629623B1 patent drawingFigure 1
  • EP2629623B1 patent drawingFigure 2

AI summary

The invention relates to a method of crystallising lactose from a lactose-containing liquid comprising the steps of providing a lactose-containing liquid comprising less than 80% by weight total solids, providing an evaporator system that comprises a heat exchanger and an evaporation vessel, the heat exchanger comprising a tube or tubes that define a flowpath having an inlet and an outlet, heating the lactose-containing liquid in the heat exchanger to about 50 to about 90° C such that the lactose-containing liquid passes along the flowpath by forced circulation or thermo-siphoning, concentrating the lactose-containing liquid in the evaporation vessel, to generate crystallised lactose in the lactose-containing liquid in the evaporator system.