Hot Water Tank Pressure Control Using Pump and Reducing Valve

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Solution Overview

Problem

Existing hot beverage preparation devices with oscillating armature pumps have low flow rates, leading to long preparation times and impaired sensory quality of coffee beverages, limiting their use to household or open systems due to pressure limitations.

Innovation Solution

A more powerful oscillating armature pump is used in combination with a pressure reducing valve to generate working pressures above the limit pressure, ensuring the pressure relief valve does not activate, resulting in higher volume flow and shorter preparation times while improving sensory quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a more powerful pump with higher working pressure is used, then volume flow and preparation speed are improved, but the pressure relief valve activates and causes water to escape continuously

Engineering Contradiction:
Improvevolume flowVSAvoidpressure control
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

A pressure reducing valve is introduced as an intermediary component between the pump and the hot water reservoir. This mediator reduces the high working pressure from the pump to a level below the pressure relief valve's activation threshold, allowing the pump to operate at high pressure for improved flow while preventing continuous water escape through the pressure relief valve.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the pressure parameter at different locations: the pump operates at high pressure (above limit pressure) to generate high flow, while the pressure reducing valve transforms this to a lower pressure (below limit pressure) at the reservoir inlet, preventing pressure relief valve activation while maintaining high productivity.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If an oscillating armature pump is used, then device cost is reduced, but flow rate is limited and preparation time increases

Engineering Contradiction:
Improvedevice costVSAvoidpreparation time
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent changes the pressure parameter by using a more powerful oscillating armature pump that operates at higher pressure. Combined with the pressure reducing valve, this allows the inexpensive pump type to achieve higher flow rates and shorter preparation times while remaining cost-effective.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the pump working pressure is kept below the pressure relief valve limit, then water escape is prevented, but volume flow and sensory quality are reduced

Engineering Contradiction:
Improvepressure controlVSAvoidsensory quality
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The pressure reducing valve serves as a mediator that decouples the pump's high pressure operation from the reservoir's pressure requirements. This allows the pump to generate high pressure for improved flow and sensory quality while the pressure reducing valve ensures the reservoir receives pressure below the relief valve activation threshold, preventing water escape.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 configuration allows for faster preparation and enhanced sensory quality of hot drinks, enabling the use of inexpensive oscillating armature pumps in high-quality commercial machines without the previous disadvantages, with optimal results achieved between 10 and 12 bar pressure ranges.

Implementation Method 1

a water pump (9) connected to the hot water tank (1) on the inlet side

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

a pressure reducing valve (13) arranged between the water pump (9) and the hot water tank (1), which reduces the water pressure on the inlet side of the water reservoir limited to a pressure value below the limit pressure

Methodology Applied
Scientific EffectPressure reduction: Pressure Drop

Implementation Method 3

a pressure relief valve (5) which is activated when the pressure exceeds a predetermined limit pressure and opens and allows hot water to escape from the hot water storage tank

Methodology Applied
Scientific EffectPressure relief: Pressure Drop

Implementation Method 4

Because water expands as it heats up in the hot water tank, the hot water tank is typically pressurized

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3597084B1Hot beverage preparation device with a hot water tank
Publication Date: 2020.09.16 FRANKE KAFFEEMASCHEN AG
  • EP3597084B1 patent drawingFigure 1~2

AI summary

In a hot beverage preparation device, in particular a coffee machine, with a hot water storage tank for heating and storing hot water, a water pump fluidly connected to the hot water storage tank on the inlet side, and a brewing device fluidly connected to the hot water storage tank on the outlet side, in which the hot water storage tank has a pressure relief valve which opens when a predetermined limit pressure is exceeded and allows hot water to escape from the hot water storage tank, it is provided that the water pump is designed in such a way that it generates a working pressure which is above the limit pressure specified by the pressure relief valve, and that a pressure reducing valve is arranged between the water pump and the hot water storage tank, which limits the water pressure on the inlet side of the water storage tank to a pressure value below the limit pressure.