Pipe Bend with Bionic Bulge to Reduce Exhaust Duct Pressure Loss

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Solution Overview

Problem

Existing pipe bends in exhaust ducts of cooker hoods experience high pressure loss and noise due to turbulent airflow, necessitating improved designs to minimize these issues.

Innovation Solution

A pipe bend with a bulge on its outer wall and asymmetrical design, featuring air guide elements with varying curvatures and cross-sectional adjustments, optimized for airflow to reduce turbulence and pressure loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a standard pipe bend with quarter circle curve is used, then the structural simplicity is maintained, but the pressure loss and noise increase due to turbulent airflow

Engineering Contradiction:
Improvestructural simplicityVSAvoidpressure loss
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The outer wall of the pipe bend is designed with a bulge that creates a bionic curved profile, deviating from the standard quarter circle. This curved design guides the airflow more smoothly around the bend, reducing turbulence and pressure loss while maintaining structural integrity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The cross-sectional area of the pipe bend is varied along its length, with a larger cross-section in the area of air guide elements compared to connection cross-sections. This parameter change optimizes flow characteristics and reduces wall friction losses.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If air guide elements are added to reduce turbulence, then pressure loss is reduced, but the device complexity increases

Engineering Contradiction:
Improvepressure lossVSAvoiddevice complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

Air guide elements are strategically positioned at specific locations within the pipe bend, particularly in areas where turbulence is most pronounced. This localized approach addresses flow problems where they occur without adding unnecessary complexity throughout the entire structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The air guide elements themselves are curved to match the bionic profile of the outer wall, creating a harmonious flow path that reduces turbulence without requiring complex angular or segmented designs.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Productivity

If the outer wall is modified with a bulge to create bionic flow pattern, then flow characteristics improve, but manufacturing complexity increases

Engineering Contradiction:
Improveflow characteristicsVSAvoidmanufacturing complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The bulge on the outer wall creates a smooth, continuous curved profile that can be manufactured using standard duct forming techniques. The curvature is designed to be achievable with common bending and shaping methods used in HVAC duct fabrication.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The cross-sectional area variations and bulge dimensions are designed with practical manufacturing tolerances in mind, allowing the bionic profile to be produced using conventional fabrication processes without requiring specialized or overly complex manufacturing steps.

Inventive Principle:
Principle #35Parameter changes

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 design achieves reduced pressure loss and noise by promoting laminar airflow and minimizing wall friction, resulting in quieter and more efficient fluid flow.

Implementation Method 1

the redirection of the airflow in the pipe bend results in at least partially non-laminar airflow due to highly turbulent air shedding and the associated turbulence within the bend

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

The design achieves reduced pressure loss and noise by promoting laminar airflow

Methodology Applied
Scientific EffectLaminar flow: Laminar Flow

Implementation Method 3

The cross-sectional expansion advantageously reduces wall friction losses and thus the pressure loss in the flow

Methodology Applied
Scientific EffectWall friction: Friction

Implementation Method 4

minimize pressure loss

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP4092340B1Pipe bend for an exhaust duct of an exhaust hood
Publication Date: 2025.10.29 NABER HOLDING GMBH & CO KG
  • EP4092340B1 patent drawingFigure 1
  • EP4092340B1 patent drawingFigure 2
  • EP4092340B1 patent drawingFigure 3

AI summary

Pipe bend, in particular for an exhaust air duct of a cooker hood, which has a deflection of 60° to 120°, preferably 90°, with an inlet side and an outlet side, wherein the pipe bend has at least one air guide element curved in the direction of deflection, which extends inside the pipe bend, characterized in that the pipe bend has a cross-sectional widening behind the inlet side, in particular adjacent to it, and a cross-sectional narrowing (18) in front of the outlet side, in particular adjacent to it, wherein the curve of the outer wall of the pipe bend deviates from the curve of a quarter circle and has a bulge located outside the apex of the pipe bend, in particular behind the apex in the direction of flow.