Capsule Delivery Wall Labyrinth Flow Path

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Solution Overview

Problem

Existing beverage capsule systems with prefabricated orifices in the delivery wall often result in low pressure rise, leading to poorly extracted coffee due to negligible back-pressure, resulting in a 'clear' and poorly extracted beverage.

Innovation Solution

The capsule design incorporates transversal restriction openings between adjacent layers, which provide resistance to beverage flow, maintaining elevated pressure and creating shear forces for foam formation, with a limited number of orifices and specific dimensions to ensure proper extraction and retention of coffee particles, and a labyrinth structure to create a tortuous flow path.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If prefabricated orifices are used in the delivery wall, then the device complexity is reduced and ease of manufacture is improved, but the pressure rise in the capsule becomes negligible and extraction quality deteriorates

Engineering Contradiction:
Improveease of manufactureVSAvoidpressure rise
Core Design Contradiction:
Ease of manufactureVSStress or pressure

Solution Approach 1:

The delivery wall is segmented into multiple functional layers: a support layer providing structural integrity and a filtering layer with controlled porosity. This segmentation allows each layer to perform its specific function - the support layer maintains structural strength while the filtering layer creates the necessary flow resistance for pressure build-up, resolving the contradiction between ease of manufacture and pressure rise capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The filtering layer is designed with specific local properties including controlled porosity (0.1-10 micrometers) and specific surface area (0.1-10 m²/g) to create optimal flow resistance. This local quality control in the filtering layer enables sufficient pressure build-up while maintaining the overall simplicity of the prefabricated orifice design

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the number of orifices is increased, then the ease of operation is improved and beverage flow is enhanced, but the back-pressure is reduced and extraction quality deteriorates

Engineering Contradiction:
Improveease of operationVSAvoidextraction quality
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The filtering layer is designed as a porous material with specific porosity parameters ( pore size 0.1-10 micrometers, specific surface area 0.1-10 m²/g). This porous structure provides controlled flow resistance that maintains back-pressure necessary for quality extraction while still allowing adequate beverage flow through the increased number of distributed pores, resolving the contradiction between ease of operation and extraction quality

Inventive Principle:
Principle #31Porous materials

3Productivity

If the orifice size is increased, then the productivity is improved and beverage delivery is faster, but the pressure build-up is reduced and extraction quality deteriorates

Engineering Contradiction:
ImproveproductivityVSAvoidpressure build-up
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The filtering layer parameters are precisely controlled including porosity (0.1-10 micrometers), specific surface area (0.1-10 m²/g), and thickness (0.1-5 mm). By optimizing these parameters, the system achieves a balance where sufficient open area provides fast beverage delivery (productivity) while the controlled porosity maintains adequate flow resistance for pressure build-up and quality extraction

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 design enhances the extraction process by maintaining elevated pressure within the capsule, promoting better interaction between water and coffee ingredients, resulting in improved coffee quality and the formation of 'crema' through controlled pressure release.

Implementation Method 1

The restriction opening provides a resistance to the flow of beverage enabling to maintain an elevated pressure in the chamber of the capsule

Methodology Applied
Scientific EffectFlow resistance: Drag

Implementation Method 2

The restriction opening also contributes to the formation of foam or coffee 'crema' by creating shear forces associated to a sudden release of pressure of liquid

Methodology Applied
Scientific EffectShear force: Shear Stress

Implementation Method 3

a labyrinth structure to create a tortuous flow path

Methodology Applied
Scientific EffectTortuous flow:

Data Source

PatentEP2239212B1Capsule for preparation of a beverage with a delivery wall forming a confined flowpath
Publication Date: 2015.11.11 NESTEC SA
  • EP2239212B1 patent drawingFigure 1~2
  • EP2239212B1 patent drawingFigure 3
  • EP2239212B1 patent drawingFigure 4

AI summary

Capsule for preparation of a beverage in a beverage production machine comprising a body and a delivery wall forming a chamber containing an extractable beverage ingredient, said delivery wall comprising at least one outlet, wherein the delivery wall comprises an inner layer including at least one first orifice and an outer layer including at least a second orifice, wherein the first and second orifices extend in the axial direction of the capsule, wherein the first and second layers are adjacent or the first and second layers are distant by a confined gap and, when a gap is present, a labyrinth structure is provided which extends transversally in said gap between the first and second orifices.