Series Jet Ejector Milk Heating for Higher Coffee Beverage Temperature

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Solution Overview

Problem

Fully automatic coffee machines struggle to heat milk to a sufficient temperature for coffee drinks like cappuccino or latte macchiato, as the existing steam heating method only achieves around 40°C, resulting in a low mixing temperature with coffee.

Innovation Solution

The use of at least two jet pumps connected in series or parallel, each with a driving nozzle generating negative pressure, allows for additional heating of milk or milk froth using steam, increasing the milk temperature to a range of 45°C to 90°C and improving suction reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a single jet pump is used to heat milk with steam, then the milk can be heated to approximately 40°C, but the temperature is too low for certain coffee drinks like cappuccino or latte macchiato

Engineering Contradiction:
Improvemilk temperatureVSAvoidheating efficiency
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The single jet pump is divided into multiple jet pumps connected in series. Each jet pump stage provides incremental heating, with the first stage heating milk to approximately 40°C and subsequent stages further heating it to reach 60°C-90°C. This segmentation allows the system to achieve higher temperatures while maintaining efficient steam utilization at each stage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multiple jet pumps operate continuously in series, with steam heating action maintained throughout each stage. The heated milk flows sequentially through each jet pump stage, receiving continuous heating action without interruption, ensuring the milk reaches the desired final temperature efficiently.

Inventive Principle:
Principle #20Continuity of useful action

2Temperature

If steam flow rate is increased to heat milk to higher temperatures, then the milk temperature can be raised, but the suction reliability deteriorates

Engineering Contradiction:
Improvemilk temperatureVSAvoidsuction reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The steam heating action is segmented across multiple jet pump stages rather than applying high steam flow rate in a single stage. Each stage uses moderate steam flow to achieve incremental temperature increases, preventing the suction reliability deterioration that would occur with excessive steam flow in a single stage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of applying excessive steam flow rate in one stage, the system applies partial heating action across multiple stages. Each jet pump stage applies a portion of the total required heating, with steam flow rates optimized for each stage to maintain suction reliability while achieving the cumulative temperature increase needed.

Inventive Principle:
Principle #16Partial or excessive 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

This solution effectively raises the milk temperature and froth temperature to a higher level, enhancing the heating process and ensuring a higher output temperature of the finished product, while also improving suction security and efficiency.

Implementation Method 1

The invention comprises at least two jet pumps connected in series or in parallel, in particular designed as individual pumps and interconnected, each having a drive nozzle for generating a vacuum

Methodology Applied
Scientific EffectVenturi effect: Venturi Effect

Implementation Method 2

The fluid drawn in by a first drive nozzle of the first jet pump due to vacuum and heated by steam can additionally be drawn in by a further drive nozzle of the second jet pump and heated further by steam

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

steam, which creates the suction (i.e., negative pressure), then enters the milk and heats it

Methodology Applied
Scientific EffectThermal energy transfer: Conduction (thermal)

Data Source

PatentEP3628193B1Beverage preparation device with jet ejectors
Publication Date: 2023.08.02 EUGSTER FRISMAG AG
  • EP3628193B1 patent drawingFigure 1
  • EP3628193B1 patent drawingFigure 2
  • EP3628193B1 patent drawingFigure 3

AI summary

The invention relates to a beverage preparation device (1), in particular a coffee machine with a brewing unit (2) for extracting coffee grounds, with at least one means (26) for heating a fluid, in particular milk, with steam, comprising a heating device (5) for heating water to form steam.