Espresso Dispenser Heater Valve Timing for Coffee Pre-Wetting
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Solution Overview
Problem
Espresso machines with a heater on each dispenser unit cannot ensure optimal wetting time for ground coffee due to instantaneous exposure to operating pressure, resulting in inadequate water dispersion.
Innovation Solution
Incorporating an additional solenoid valve device that can be programmed to close for a customizable duration, allowing the water temperature and pressure to increase gradually before reaching the operating pressure, enabling adjustable wetting times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If water heater on dispenser unit is used, then heating efficiency is improved, but wetting time control deteriorates
Solution Approach 1:
The water supply path is segmented into two separate valves: a first valve controlling water supply to the water heater, and a second valve controlling water supply to the dispensing conduit. This segmentation allows independent control of heating water and dispensing water, enabling precise wetting time control while maintaining heating efficiency.
Solution Approach 2:
A programmable controller is introduced as an intermediary to coordinate the operation of the first and second valves. The controller programs the timing sequence where the first valve opens before the second valve, creating the desired wetting time delay without compromising the heating system's efficiency.
2Device complexity
If traditional pump pressure system is used, then water pressure control is simple, but wetting time becomes too short
Solution Approach 1:
The water supply system is divided into two controlled pathways: one through the water heater and another through the dispensing conduit. By using separate valves for each pathway, the system can control the timing of water arrival at the coffee grounds, extending the wetting time while maintaining relatively simple pressure control through the existing pump system.
3Speed
If water is expelled at maximum operating pressure, then dispensing speed is improved, but coffee brewing quality deteriorates
Solution Approach 1:
The system performs preliminary action by opening the first valve to supply water to the heater before opening the second valve to dispense water. This creates a time sequence where water is heated in advance and then dispensed at the optimal moment, ensuring both adequate wetting time for quality brewing and maintaining dispensing speed through the pre-heated water ready in the heater.
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
Enables adjustable and customizable wetting times for ground coffee, ensuring optimal water dispersion and beverage quality by allowing the water to reach the filter holder at a pressure slightly above 1 bar before increasing to the operating pressure of 9 ± 1 bar.
Implementation Method 1
Incorporating an additional solenoid valve device that can be programmed to close for a customizable duration
Implementation Method 2
a water heater placed on the dispenser unit
Implementation Method 3
a source of pressurized water
Data Source
Figure 1
AI summary
An improved device for wetting a dose of ground coffee in coffee machines, preferably espresso machines, particularly but without limitation professional espresso making machines. The device comprises a source of pressurized water (4), at least one beverage dispenser unit (13), a filter holder (15) removably coupled to said dispenser (13), a water heater (12) placed on the dispenser unit, a water supply system (3, 11) connecting said source of pressurized water (4) with said heater (12), a dispensing conduit (23) connecting the heater (12) with the dispenser unit (13), as well as a dispensing valve device (26) inserted in said dispensing conduit (23) for closing and opening the conduit and for feeding heated water to the filter holder (15) and cause it to spread into the dose of ground coffee contained in the filter holder, as well as an electronic control and programming unit (22) connected at least with said source of pressurized water (4), with said heater (12) and with said dispensing valve device (26). The device further comprises an additional valve device (28) located on said water supply system (3, 11) which connects said source of pressurized water (4) with said heater (12), said additional valve device (28) being connected to said electronic control and programming unit.