Brewing apparatus for preparing a hot beverage
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Solution Overview
Problem
Commercial coffee machines experience significant fluctuations in coffee taste and quality due to variables like coffee type, grinding degree, and compression, leading to inconsistent brews, especially after extended inactivity periods.
Innovation Solution
A brewing apparatus with a controllable backpressure valve downstream of the brewing chamber, actuated by a motor-operated needle valve, maintains constant pressure across the coffee mass, allowing for precise control of the brewing process throughflow rate and time, compensating for differences in coffee powder grinding and optimizing coffee extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a mechanical control valve with spring pretension is used to maintain constant throughflow rate, then the relative throughflow rate can be kept constant within certain limits, but the taste and quality of the brewed beverage still experience severe fluctuations due to variations in coffee powder characteristics and compression
Solution Approach 1:
The patent implements a feedback control system where a measuring device (flow meter or pressure sensor) continuously monitors the actual throughflow rate or pressure, and the controller adjusts the backpressure valve position based on this feedback to maintain the desired throughflow rate. This closed-loop control compensates for variations in coffee powder characteristics, grinding degree, and compression, ensuring consistent coffee quality throughout the brewing process and after extended inactivity periods.
Solution Approach 2:
The patent replaces the purely mechanical spring-based control valve with an electronically controlled backpressure valve actuated by a motor (such as a stepper motor or piezoelectric actuator). This substitution allows for more precise and dynamic adjustment of the valve opening based on electronic control signals from the controller, enabling finer control resolution and faster response to maintain constant throughflow rate under varying conditions.
2Shape
If the brewing chamber pressure is increased using a throttle valve downstream to obtain better crema, then the crema quality improves, but the pressure drop across the coffee mass increases leading to greater fluctuations in throughflow rate and coffee quality
Solution Approach 1:
The patent extracts the pressure regulation function from the downstream throttle valve and relocates it to a backpressure valve positioned downstream of the brewing chamber. This separation allows the brewing chamber pressure to be maintained at optimal levels for coffee extraction and crema formation, while the backpressure valve independently controls the throughflow rate by regulating pressure downstream, preventing the coupling of these two functions that caused the quality fluctuations.
Solution Approach 2:
The patent employs a dynamically adjustable backpressure valve that can modify its opening position during the brewing process based on feedback from the measuring device. This dynamic adjustment capability allows the system to compensate for pressure variations caused by different coffee powder characteristics, grinding degrees, and compression levels, maintaining constant throughflow rate while still achieving optimal crema quality through appropriate pressure management.
3Reliability
If coffee powder is freshly ground and compressed in the brewing chamber, then the coffee quality should be optimal, but after extended inactivity periods the first dispensed coffee has extremely poor taste and quality
Solution Approach 1:
The feedback control system continuously monitors the actual throughflow rate or pressure during the brewing process and adjusts the backpressure valve to maintain the desired brewing conditions. This ensures consistent extraction quality regardless of when the brewing occurs, eliminating the degradation effect of extended inactivity periods by compensating for changes in coffee powder characteristics that occur over time through precise control of the brewing parameters.
4Manufacturing precision
If a motor-operated needle valve is used for backpressure control, then exact and rapid-response control of throughflow rate is achieved, but the device complexity increases
Solution Approach 1:
The patent replaces complex mechanical control mechanisms with an electrically actuated needle valve controlled by a motor (such as a stepper motor or piezoelectric actuator). This substitution simplifies the overall control system by using electronic control signals instead of complex mechanical linkages, while providing precise and rapid adjustment of the valve opening. The motor-driven mechanism offers fine control resolution and fast response time, and the control logic can be implemented in software, reducing mechanical complexity.
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 consistent coffee quality by regulating the brewing process at a constant throughflow time, reducing the impact of coffee powder grinding variations and allowing for the use of coarser grinds, while also optimizing coffee extraction and reducing coffee powder usage.
Implementation Method 1
active control of the backpressure which is generated by a backpressure valve which is arranged downstream of the brewing chamber in the flow direction, so that the pressure across the coffee mass which is contained in the brewing chamber can be kept substantially constant over the entire brewing process
Implementation Method 2
the needle valve used according to the invention allows firstly particularly exact and secondly rapid-response control of the throughflow rate
Implementation Method 3
a measuring device, which is arranged upstream or downstream of the brewing chamber, for determining a volume flow rate of the brewing water or a quantity of the brewing water which has already been conducted through or is still to be conducted through
Data Source
AI summary
In a method and an associated brewing apparatus for preparing a hot beverage, in particular a coffee beverage, a quantity of a flavoring source, in particular coffee powder, is introduced into a brewing chamber and then, in a brewing operation, a predeterminable overall quantity of brewing water is passed through the brewing chamber under pressure, in order to enhance the taste quality of the freshly brewed coffee beverages or at least to increase the consistency of the taste. During the brewing operation, a value for the volume flow of the brewing water upstream or downstream of the brewing chamber, and/or for the quantity of the brewing water which has already been passed through, or is still to be passed through, is determined continuously, or at least a number of times, and a controllable backpressure valve downstream of the brewing chamber is activated in accordance with the value determined. The backpressure valve is a motor-operated needle valve which the controller opens wider or closes by activating a corresponding drive motor.