Combination device with a cooker hob and extractor device

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Solution Overview

Problem

Existing kitchen ventilation systems, particularly those using downdraft fans, require significant space and impose high demands on suction fans due to the long distance between the cooking area and the vacuum source, leading to inefficiencies in vapor extraction and increased risk of dirt and liquids entering the fan.

Innovation Solution

A combination appliance with a hob and extractor hood design featuring at least two recesses in the hob to reduce the distance air travels to the fan, integrating the hob and extractor device as a single unit with the fan positioned below the hob, and incorporating a radial fan with an upward-facing air inlet opening to minimize airflow deflection and protect the fan from contaminants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the fan is positioned far from the cooktop (as in separate downdraft ventilation systems), then the extraction of cooking vapors can be achieved, but the space requirement increases and the demands on the negative pressure source increase

Engineering Contradiction:
Improveextraction of cooking vaporsVSAvoidspace requirement
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent combines the cooktop and extractor hood into a single integrated unit, with the fan positioned directly below the cooktop surface. This merging eliminates the need for separate ventilation systems and long exhaust ducts, reducing space requirements while maintaining effective vapor extraction through the integrated design

Inventive Principle:
Principle #5Merging (Combining)

2Volume of moving object

If the fan is positioned close to the cooktop, then the space requirement is reduced, but the risk of dirt and liquids entering the fan increases

Engineering Contradiction:
Improvespace requirementVSAvoiddirt and liquids entering fan
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent implements a differentiated design where the front portion of the fan housing remains accessible for air intake, while the rear portion is sealed and integrated with the exhaust duct system. This local quality differentiation allows the fan to be positioned close to the cooktop for space efficiency while protecting critical components from contaminants through selective sealing

Inventive Principle:
Principle #3Local quality

3Device complexity

If radial fans are used with upward airflow from below, then the fan can be positioned below the cooktop, but the requirements for the fans to generate sufficient negative pressure are increased due to large airflow distance

Engineering Contradiction:
Improvefan positioningVSAvoidnegative pressure generation
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

The patent transitions from vertical airflow (upward from below) to horizontal airflow by positioning the fan laterally adjacent to the cooktop surface. This dimensional change allows the fan to draw air horizontally across a short distance and discharge it laterally, eliminating the need to generate high negative pressure over long vertical distances while maintaining effective vapor extraction

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Ease of operation

If extraction openings are located at the edges of the cooktop, then air can be drawn downwards, but the distance air has to travel to the fan is considerable

Engineering Contradiction:
Improveairflow directionVSAvoidair travel distance
Core Design Contradiction:
Ease of operationVSLength of moving object

Solution Approach 1:

The patent extracts the fan from its traditional position within the cooktop structure and positions it laterally adjacent to the cooktop surface. This extraction allows air to be drawn directly across the cooktop surface through nearby openings and immediately captured by the fan, minimizing the travel distance while maintaining the downward airflow extraction effect

Inventive Principle:
Principle #2Taking out (Extraction)

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 design simplifies the structure, reduces the demands on the fan, prevents dirt and liquids from entering, and enhances the extraction of cooking vapors while reducing the overall height and noise of the ventilation system.

Implementation Method 1

the requirements for the radial fans to generate sufficient negative pressure are increased

Methodology Applied
Scientific EffectNegative pressure generation: Pressure Gradient

Implementation Method 2

A suction fan is located at the outer end of the exhaust duct

Methodology Applied
Scientific EffectAirflow generation: Fan

Data Source

PatentEP3136004B1Combination device with a cooker hob and extractor device
Publication Date: 2019.10.09 BSH HAUSGERATE GMBH
  • EP3136004B1 patent drawingFigure 1
  • EP3136004B1 patent drawingFigure 2
  • EP3136004B1 patent drawingFigure 3

AI summary

The present invention relates to a combination appliance comprising a hob (10) with at least one cover plate (103) and at least one heating element (101) and an extractor device (11) arranged below the hob (10) with a fan (110) for extracting air from the space above the hob (10). The combination appliance (1) is characterized in that at least two recesses (104) are made in the hob (10) and the at least two recesses (104) are arranged offset horizontally with respect to the fan (110) arranged under the hob (10) and the edge of the recesses (104) in vertical projection onto the underlying fan (110) lies close to or partly on the edge of the air inlet opening (115) of the fan (110).