Sanitary Liquid Dispensing with Thermostatic Recirculation

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Solution Overview

Problem

Existing sanitary facilities require significant installation space and are costly due to the need for instantaneous water heaters or gas boilers to compensate for temperature drops in recirculated water, leading to high water consumption.

Innovation Solution

A sanitary device with a first thermostat to mix recirculated water with hot or cold water to achieve a tempered circulating liquid, and a second thermostat to mix hot and cold water for a desired mixed water temperature, eliminating the need for continuous flow heaters and reducing space and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If instantaneous water heater or gas boiler is used to compensate temperature drop in recirculated water, then temperature control is improved, but installation space requirement increases and cost increases

Engineering Contradiction:
Improvetemperature controlVSAvoidinstallation space requirement
Core Design Contradiction:
TemperatureVSVolume of stationary object

Solution Approach 1:

The patent extracts the temperature compensation function from traditional bulky instantaneous water heaters or gas boilers and integrates it into a compact thermostat device. The thermostat directly mixes recirculated water with fresh hot or cold water to achieve temperature compensation, eliminating the need for separate heating equipment and reducing installation space.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges multiple functions (temperature control, water mixing, and recirculation management) into a single integrated thermostat system. This combination allows the device to perform temperature compensation for recirculated water without requiring additional space-heating equipment, thereby resolving the contradiction between temperature control and installation space.

Inventive Principle:
Principle #5Merging (Combining)

2Temperature

If instantaneous water heater or gas boiler is used to compensate temperature drop in recirculated water, then temperature control is improved, but cost increases

Engineering Contradiction:
Improvetemperature controlVSAvoidcost
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent extracts the temperature compensation function from expensive instantaneous water heaters or gas boilers and implements it through a simpler thermostat-based mixing system. This extraction eliminates the need for costly heating equipment while maintaining effective temperature control, thereby reducing overall system cost.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces expensive, complex heating equipment with a simpler, more cost-effective thermostat-based mixing system. This substitution uses readily available components (thermostat, valves, pipes) instead of costly instantaneous water heaters or gas boilers, achieving the same temperature control function at lower cost.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Loss of substance

If recirculated water is used in sanitary facilities, then water consumption is reduced, but temperature drop requires additional heating equipment

Engineering Contradiction:
Improvewater consumptionVSAvoidequipment complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The patent merges the recirculation system with a compact thermostat-based temperature control system, eliminating the need for separate heating equipment. This integrated approach maintains water conservation benefits while reducing equipment complexity by using a unified mixing and control mechanism.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces complex mechanical heating systems (instantaneous water heaters or gas boilers) with a simpler thermostat-controlled mixing system. This substitution uses thermal mixing principles instead of active heating mechanisms, reducing equipment complexity while maintaining effective temperature control for recirculated water.

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

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

The solution achieves reduced installation space and lower costs by effectively tempering recirculated water and mixing fresh water without continuous flow heaters, while maintaining temperature control.

Implementation Method 1

the circulating liquid can be mixed with hot water or cold water by the first thermostat to form a tempered circulating liquid

Methodology Applied
Scientific EffectThermal mixing:

Implementation Method 2

hot water and cold water can be mixed by the second thermostat to form mixed water with a mixed water target temperature

Methodology Applied
Scientific EffectThermal mixing:

Data Source

PatentEP4194628B1Sanitary device with at least one dispensing device for a liquid
Publication Date: 2025.09.24 GROHE AG
  • EP4194628B1 patent drawingFigure 1~2
  • EP4194628B1 patent drawingFigure 3

AI summary

Sanitary installation (1), comprising at least: - at least one dispensing device (2, 3) for a liquid; - a basin (4) with a drain (5) for the liquid; and - a first thermostat (6) to which at least a portion of the liquid drained via the drain (5) can be supplied as a circulating liquid, wherein the circulating liquid can be mixed with hot water or cold water by the first thermostat (6) to form a temperature-controlled circulating liquid and wherein the temperature-controlled circulating liquid can be supplied to the at least one dispensing device (2, 3).