Milk Frothing Chamber Cleaning via Alternating Steam and Air Paths

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Solution Overview

Problem

Automatic coffee machines with milk frothing devices face issues with incomplete cleaning of the foaming chamber and milk intake area, leading to residue buildup, especially when cleaning is delayed after making milk-based drinks, and existing cleaning methods may not effectively remove adhering residues.

Innovation Solution

An automatic coffee machine with a milk frothing device featuring a hot water/steam supply conduit, a milk supply conduit, and an air supply conduit, utilizing a maintenance solenoid valve to alternately send hot water/steam through both conduits via a connecting conduit, leveraging the Venturi effect for enhanced cleaning power, and including a drying cycle to prevent bacterial growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If hot water is sent only through the hot water/steam supply duct during cleaning, then the cleaning system is simple to operate, but the frothing chamber and milk inlet area are not sufficiently cleaned and residues remain

Engineering Contradiction:
Improvecleaning operation simplicityVSAvoidcleaning effectiveness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The cleaning process is segmented into two distinct phases: first sending hot water through the hot water/steam supply duct to clean the frothing chamber and milk inlet area, then sending hot water through the air supply duct to clean the air supply and milk supply pipes. This segmentation ensures each area receives targeted cleaning attention, resolving the contradiction between simple operation and effective cleaning.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cleaning system uses periodic action by alternately switching between two cleaning paths through the maintenance solenoid valve. The control circuit automatically sequences the cleaning process, first directing hot water through one path, then through the other path, ensuring thorough cleaning without requiring complex manual intervention.

Inventive Principle:
Principle #19Periodic action

2Ease of manufacture

If only hot water is used for cleaning, then the cleaning system is economical and simple, but stubborn residues cannot be effectively removed

Engineering Contradiction:
Improvecleaning system simplicityVSAvoidresidue removal capability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The system changes the parameter of the cleaning fluid by heating water to high temperatures in the boiler before injecting it through the maintenance solenoid valve. This parameter change (temperature increase) enhances the cleaning power to remove stubborn residues while keeping the system simple and economical by using only water as the cleaning agent.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The high-temperature hot water is rushed through the cleaning paths at high velocity, generating mechanical force that helps detach stubborn residues. This rushing action complements the thermal effect, providing enhanced cleaning capability without adding complex mechanical cleaning components.

Inventive Principle:
Principle #21Skipping (Rushing through)

3Productivity

If cleaning is delayed after making milk-based drinks, then the machine can continue operating, but adhering residues build up and become difficult to remove

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidcleaning effectiveness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs preliminary cleaning action by automatically executing a cleaning cycle using high-temperature hot water immediately or shortly after milk-based drinks are made. This preliminary action prevents residue buildup by removing milk residues before they can adhere strongly to the surfaces, enabling continuous operation while maintaining cleaning effectiveness.

Inventive Principle:
Principle #10Preliminary 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

The solution ensures thorough cleaning and drying of the milk frothing device, effectively removing residues and preventing bacterial growth, even when cleaning is delayed, while maintaining a safe and ergonomic operation with a simple and economical design.

Implementation Method 1

a section restriction forming a milk and air suction system based on the venturi effect

Methodology Applied
Scientific EffectVenturi effect: Venturi Effect

Implementation Method 2

a boiler producing hot water and/or steam

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

at least one maintenance solenoid valve arranged on at least the hot water/steam supply duct, the control circuit controlling the boiler and the at least one maintenance solenoid valve for sending hot water/steam into the air supply duct

Methodology Applied
Scientific EffectFluid flow control: Valve

Data Source

PatentEP4108143B1Automatic coffee machine equipped with a milk foaming device with improved cleaning
Publication Date: 2024.05.01 SEB SA
  • EP4108143B1 patent drawingFigure 1
  • EP4108143B1 patent drawingFigure 2
  • EP4108143B1 patent drawingFigure 3

AI summary

The invention relates to an automatic coffee machine (1) comprising a milk frothing device (40) including a frothing chamber (42) supplied by a hot water/steam supply duct (32), a milk supply duct (43) and an air supply duct (44), the hot water/steam supply duct (32) including a section restriction (41) forming a milk and air suction system based on the venturi effect, the automatic coffee machine (1) including a boiler (33) producing hot water and/or steam, a control circuit (60) and at least one maintenance solenoid valve (51) arranged on at least the hot water/steam supply duct (32), the control circuit (60) including a cleaning program for the milk frothing device (40) and an activation element (61) for the cleaning program.According to the invention, the milk foaming device (40) includes a connecting conduit (50) linking the hot water/steam supply conduit (32) and the air supply conduit (44) and, during the cleaning program, the control circuit (60) controls the boiler (33) and at least one maintenance solenoid valve (51) to send hot water/steam alternately into the hot water/steam supply conduit (32) and into the air supply conduit (44), through the connecting conduit (50).