Coffee Machine Pump Control for Flow-Responsive Capsule Extraction

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Solution Overview

Problem

Coffee machines using portion capsules often experience flow blockages due to fluctuations in capsule properties and brewing conditions, leading to incomplete coffee extraction and unsatisfactory taste, especially with finely ground coffee, as high pressure increases flow resistance and can cause blockages.

Innovation Solution

A coffee machine with a controller that adjusts pump output based on liquid flow, reducing pressure when flow decreases to prevent blockages by enlarging channels and loosening coffee beds, allowing for consistent brewing regardless of capsule variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high pump pressure is applied to ensure complete coffee extraction, then extraction quality is improved, but flow resistance increases causing blockages

Engineering Contradiction:
Improveextraction qualityVSAvoidflow blockage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The pump pressure is made dynamic rather than constant. The controller continuously monitors liquid flow and adjusts pump output in real-time, reducing pressure when flow decreases to prevent blockages, and maintaining or increasing pressure when flow is adequate to ensure extraction quality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A feedback control system is implemented where the liquid flow is measured and used to adjust pump pressure. The controller receives flow information and automatically modifies pump output to maintain optimal extraction while preventing blockages, creating a closed-loop control system.

Inventive Principle:
Principle #23Feedback

2Productivity

If pump power is increased to maintain liquid flow, then flow rate is improved, but flow resistance increases causing complete standstill

Engineering Contradiction:
Improveliquid flow rateVSAvoidflow standstill
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

Instead of increasing pump power to overcome flow resistance, the system inverts the approach by reducing pump pressure when flow resistance increases. This counter-intuitive strategy allows the flow channels to enlarge and coffee beds to loosen, actually improving flow rate while preventing standstill.

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

Solution Approach 2:

The pump pressure parameter is dynamically changed based on flow conditions. When liquid flow decreases, the controller reduces pump pressure, which changes the physical state of the coffee bed and flow channels, allowing them to loosen and enlarge, thereby restoring flow.

Inventive Principle:
Principle #35Parameter changes

3Duration of action of moving object

If conventional pump control is used to ensure complete brewing, then brewing time is extended, but pump load increases and taste quality deteriorates

Engineering Contradiction:
Improvebrewing timeVSAvoidpump load
Core Design Contradiction:
Duration of action of moving objectVSPower

Solution Approach 1:

The system uses flow feedback to determine when brewing is complete. Instead of relying on fixed brewing time or high pump load, the controller monitors liquid flow and can terminate brewing when adequate extraction is achieved, reducing unnecessary pump operation and improving taste quality.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system applies pump pressure selectively and moderately rather than continuously at maximum capacity. By adjusting pressure based on actual flow needs, the system achieves complete extraction without excessive pump load or extended brewing time.

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 ensures a high percentage of capsules are brewed to quality standards by preventing blockages and maintaining flow, ensuring complete extraction and improved taste by dynamically adjusting pump output in response to changing flow conditions.

Implementation Method 1

a water supply having a pump... for supplying water to the brewing chamber under pressure

Methodology Applied
Scientific EffectPressure increase: Pressure Increase

Data Source

PatentEP3145373B1Coffee machine for cartridges
Publication Date: 2019.08.21 TCHIBO SCHWEIZ AG
  • EP3145373B1 patent drawingFigure 1~3b
  • EP3145373B1 patent drawingFigure 2a~2f
  • EP3145373B1 patent drawingFigure 4~5

AI summary

The invention relates to an extraction device, particularly a coffee machine, comprising a brewing module (10) that forms a brewing chamber for a single-portion capsule (12), and a water supply line with a pump (5) and, in general, also a water heater (7) for supplying water to said brewing chamber under pressure. Said extraction device also comprises a control system (9) for the pump - this can be integrated into the pump or provided at least partially externally to the pump - as well as means for measuring a flow of liquid into said brewing chamber. According to the invention, the control system (9) is configured such that at least under certain conditions, a pump (5) output is dependent on the flow of liquid specifically such that the pump output when there is a smaller liquid flow is reduced in comparison to when there is a greater liquid flow.