Membrane Foam Module for Coffee Machines to Reduce Residue Buildup

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Solution Overview

Problem

Existing beverage preparation devices, particularly fully automatic coffee machines, face limitations in foam temperature, consistency, and air content, and struggle with hygienically problematic residues and deposits in foaming modules, despite existing methods for minimizing these issues.

Innovation Solution

A method utilizing a porous membrane in a fluid chamber, where a motive fluid is conveyed through the membrane to incorporate propellant gas into the fluid to be foamed, allowing for cold foam production and simplified cleaning by reversing the pump direction and using propellant fluid to remove residues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a Venturi nozzle or jet pump is used for foaming, then the device can produce foam with varied temperature, air content, and consistency, but residues and deposits of foaming fluid accumulate in the module causing hygienic problems

Engineering Contradiction:
Improvefoam varietyVSAvoidresidues and deposits
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts the foaming process from the main fluid path by using a separate gas injection system. Gas is introduced through a nozzle into the milk stream, creating foam without requiring the milk to pass through complex Venturi structures where residues would accumulate. This separates the foaming function from the fluid transport path.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of forcing milk through a Venturi nozzle to create foam (liquid through gas path), the invention inverts the approach by injecting gas into the liquid stream. This reversal simplifies the fluid path and eliminates the need for complex internal structures that trap residues, while still achieving effective foaming.

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of operation

If the foaming module is designed to minimize residues through specific operating methods, then cleaning is improved, but the range of foam properties (temperature, consistency, air content) remains limited

Engineering Contradiction:
Improvecleaning easeVSAvoidfoam properties range
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The gas injection nozzle serves multiple functions: it creates foam with varied air content, influences foam consistency through injection timing and duration, and can be integrated with heating elements to control foam temperature. This single component enables diverse foam properties without complicating the overall structure, maintaining ease of cleaning.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system dynamically controls foam properties by varying the gas injection parameters (flow rate, timing, duration) during the foaming process. This dynamic adjustment allows the production of different foam types (dense, airy, hot, cold) using the same simplified hardware, maintaining both versatility and ease of operation.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If complex foam module designs are used to achieve diverse foam properties, then foam versatility is improved, but the complexity of the device increases making cleaning more difficult

Engineering Contradiction:
Improvefoam diversityVSAvoidmodule complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The foaming function is segmented into a separate gas injection system independent of the milk transport path. This segmentation allows the milk path to remain simple and easy to clean, while the gas injection component (a simple nozzle) handles the complexity of foam generation. The two functions are separated but coordinated during operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses a porous structure in the gas injection nozzle to distribute gas uniformly into the milk stream. This porous design achieves consistent foam quality and diverse foam properties through simple material selection rather than complex mechanical structures, maintaining ease of cleaning while providing foam versatility.

Inventive Principle:
Principle #31Porous materials

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

Enables a wide range of foam properties and simplifies cleaning by minimizing residues and deposits, with the ability to produce customizable foams and maintain hygiene.

Implementation Method 1

a preferably porous membrane of the foaming module is traversed with a motive fluid from a first membrane surface to a second membrane surface of the membrane

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 2

a fluid chamber in which the second membrane surface of the membrane is arranged is traversed with a fluid to be foamed, preferably containing protein, preferably milk

Methodology Applied
Scientific EffectGas incorporation through membrane traversal:

Data Source

PatentEP4434414B1Method for operating a beverage preparation device, in particular a fully automatic coffee maker with a membrane foam module
Publication Date: 2025.11.26 EUGSTER FRISMAG AG
  • EP4434414B1 patent drawingFigure 1~2

AI summary

The invention relates to a method for operating a beverage preparation device (01), in particular a fully automatic coffee machine, with a foaming module (20) comprising a foaming operation, wherein the foaming operation is characterized by the following process steps: - Flowing a motive fluid through a, preferably porous, membrane (10) of the foaming module (20) from a first membrane surface to a second membrane surface of the membrane (10); - Flowing a fluid to be foamed, preferably containing protein, from a fluid chamber in which the second membrane surface of the membrane (10) is arranged, wherein the fluid to be foamed is conveyed by a feed pump (15), in particular a roller pump, which engages a supply line (07) that connects a container (08), preferably a milk container, to the fluid chamber.