Coffee Bean Roasting Control Using Weight Loss Rate Feedback

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Solution Overview

Problem

Existing coffee roasting apparatuses struggle to achieve consistent roasting results due to variations in coffee bean varieties and initial roasting levels, as determining roasting time and temperature alone is insufficient to ensure a desired roasting degree, and relying on color may not guarantee consistency.

Innovation Solution

An apparatus with a processor that monitors the weight loss rate of coffee beans, using a sensor to determine the elapsed time between weight measurements and calculating the weight loss rate to select an appropriate roasting profile or terminate the roasting process based on the desired weight loss, ensuring consistent roasting results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the user specifies roasting time or temperature, then the roasting process can be controlled, but consistent roasting results cannot be achieved due to variations in coffee bean varieties and initial roasting levels

Engineering Contradiction:
Improveroasting consistencyVSAvoidadaptability to different coffee bean varieties
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system continuously monitors the weight of coffee beans during roasting and uses this feedback to dynamically adjust the roasting process. The processor calculates weight loss rate and compares it against target profiles, automatically modifying heating parameters to maintain consistent roasting results across different coffee bean varieties and initial roasting levels.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the control parameter from fixed time or temperature specifications to dynamic weight loss rate monitoring. By tracking the rate at which coffee beans lose weight during roasting, the system adapts to different coffee bean characteristics and adjusts roasting parameters in real-time to achieve consistent results.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If color is used to determine roasting degree, then visual assessment is simple, but it does not guarantee consistent roasting results across different coffee bean varieties

Engineering Contradiction:
Improveease of roasting assessmentVSAvoidroasting degree consistency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system replaces visual color assessment with an automated weight-based measurement system. A sensor continuously monitors coffee bean weight, and the processor calculates weight loss rate, providing an objective and consistent metric for determining roasting degree that eliminates the subjectivity and inconsistency of visual color assessment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system introduces weight loss rate as an intermediary parameter between the roasting process and the final roasting degree determination. Instead of directly observing color changes, the system uses weight loss as a reliable indicator that correlates with the chemical and physical changes occurring during roasting, providing a more consistent measurement across different coffee bean varieties.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If fixed roasting time is used, then the process is simple to control, but it cannot accommodate different initial roasting levels of coffee beans

Engineering Contradiction:
Improvecontrol simplicityVSAvoidaccommodation of different initial roasting levels
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system transitions from static fixed-time control to dynamic time-based control where the roasting duration and intensity are continuously adjusted based on real-time weight measurements. The processor monitors weight loss rate and automatically modifies the roasting timeline to accommodate different initial roasting levels, making the process adaptive rather than rigid.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system enables the coffee beans to essentially control their own roasting process by monitoring their own weight loss. The sensor detects changes in the coffee beans' weight, and the processor uses this information to automatically adjust the roasting parameters, allowing the material itself to guide the processing parameters rather than relying on predetermined fixed schedules.

Inventive Principle:
Principle #25Self-service

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 allows for precise control of the roasting process, ensuring consistent roasting results by determining the roasting degree based on weight loss rates, which correlates with the roasting level, thereby improving the consistency and quality of roasted coffee.

Implementation Method 1

The apparatus may further comprise a sensor for monitoring the weight of the coffee beans in said compartment

Methodology Applied
Scientific EffectGravitation: Gravitation

Implementation Method 2

fresh, i.e. green, coffee beans can be roasted by a thermal process, e.g. using hot gases or by physical contact with a hot surface

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

complex chemical reactions such as Maillard reaction and pyrolysis are induced

Methodology Applied
Scientific EffectMaillard reaction:

Implementation Method 4

complex chemical reactions such as Maillard reaction and pyrolysis are induced

Methodology Applied
Scientific EffectPyrolysis: Pyrolysis

Data Source

PatentEP3193684B1Apparatus and method for roasting coffee beans, and coffee machine
Publication Date: 2019.08.07 KONINKLIJKE PHILIPS NV
  • EP3193684B1 patent drawingFigure 1
  • EP3193684B1 patent drawingFigure 2
  • EP3193684B1 patent drawingFigure 3

AI summary

A apparatus (100) for roasting coffee beans is disclosed comprising a compartment (110) for holding coffee beans (10); a roasting element (140) for roasting the coffee beans in said compartment; and a processor (130) comprising a control unit (134) for controlling the roasting element. Wherein, the processor (130) is adapted to determine a weight loss rate of the coffee beans, and the control unit (134) is adapted to control the roasting element as a function of the determined weight loss rate. A coffee machine including such an apparatus and a method for roasting coffee beans are also disclosed.