Curved Air Guide Rib for Uniform Low-Resistance Food Heating

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Solution Overview

Problem

Existing food preparation apparatuses suffer from significant heat loss due to air flow resistance and inefficient heat transfer, leading to increased energy consumption, inconsistent baking results, and longer preparation times, as they often rely on either vertical or cyclonic air flow patterns that are either energy-intensive or result in poor heat distribution.

Innovation Solution

The apparatus features an air guide rib arranged along a curved line with a concave side, forming an angle less than 90° with the bottom part, creating a hybrid air flow pattern that combines high upward velocity with a central rotating air core, reducing flow resistance and enhancing heat transfer for consistent and efficient cooking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If vertical air flow is used to achieve high upward speed and effective heat transfer, then heat transfer efficiency is improved, but power consumption increases substantially due to the vast energy required to divert the circulating air

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The air guide rib is configured with a curved geometry and a concave side forming an angle less than 90° with the bottom part, creating a hybrid flow pattern that combines vertical upward movement with rotational motion. This curved configuration reduces flow resistance and allows the air to follow a more efficient path, achieving high heat transfer efficiency without requiring excessive power to divert the air flow

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Use of energy by moving object

If cyclonic air flow pattern is used to reduce energy consumption, then power consumption is reduced, but baking consistency deteriorates due to large differences in heat distribution between central and wall areas

Engineering Contradiction:
Improvepower consumptionVSAvoidbaking consistency
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The air guide rib creates a hybrid flow pattern with distinct regions: a central rotating air core for consistent heat distribution and peripheral upward flow for effective heat transfer. This local differentiation of flow characteristics ensures uniform baking quality throughout the food preparation chamber while maintaining energy efficiency

Inventive Principle:
Principle #3Local quality

3Productivity

If air flow path is extended to allow air to contact food surface, then heat transfer to food is improved, but flow resistance increases causing substantial energy loss

Engineering Contradiction:
Improveheat transfer to foodVSAvoidenergy loss due to flow resistance
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The curved configuration of the air guide rib with its concave side at an angle less than 90° creates an optimized flow path that allows air to contact the food surface effectively while minimizing flow resistance. The hybrid flow pattern combines vertical upward movement with rotation, enabling efficient heat transfer without excessive energy loss

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 results in improved heat distribution and baking quality, reducing preparation time and energy consumption by minimizing air flow resistance while maintaining high vertical velocity and a rotating central air core, leading to more consistent and efficient food preparation.

Implementation Method 1

the food is heated from below by convection (by means of the air flow) and from above by radiation (by the heat radiating means) simultaneously

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

a centrally located core of rotating air. This results in a low air flow resistance

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

the food is heated from below by convection (by means of the air flow) and from above by radiation (by the heat radiating means) simultaneously

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 4

The air, which is heated by the heat radiating means, circulates within the apparatus and prepares the food

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2347186B1Apparatus for preparing food and air guide member therefor
Publication Date: 2016.02.17 KONINKLIJKE PHILIPS NV
  • EP2347186B1 patent drawingFigure 1~2
  • EP2347186B1 patent drawingFigure 3~4
  • EP2347186B1 patent drawingFigure 5~7

AI summary

An apparatus for preparing food comprises a food preparation chamber with an air-permeable bottom wall and an upper air discharge opening, a fan for moving hot air succesively through the bottom wall, the food preparation chamber and the discharge opening, air guide means for returning the air from the discharge opening towards the bottom wall separate from the food preparation chamber, heat radiating means positioned in the upper part of the food preparation chamber and air guide means below the food preparation chamber and on top of a bottom part for directing the air flow essentially upwards into food present in the food preparation chamber. Said air guide means comprises at least one air guide rib arranged along a curved line extending substantially towards a central region of said bottom part, wherein said air guide rib is provided with a concave side which, as seen in a vertical section through said air guide rib, along at least part of its extension along said curved line in¬ cludes an angle with the bottom part smaller than 90°.