Air ejector system for a portable dry vacuum cleaning unit

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Solution Overview

Problem

Existing dry vacuum cleaners face challenges in achieving a compact and flexible design due to high exhaust air speed, which leads to dust turbulence and discomfort for users and bystanders, especially in compact models.

Innovation Solution

The air blow-out system incorporates a receiving bay in the vacuum cleaner's housing that can accommodate either an air filter insert or a blow-out adapter, allowing for filtered exhaust air or direct blower hose connection, with a diffuser design and modular components to reduce exhaust velocity and provide a large flow cross-section, positioned over a corner of the housing to optimize space and reduce blowing force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the exhaust opening cross-sectional area is reduced to make the vacuum cleaner more compact, then the device size is reduced, but the exhaust air speed increases causing dust turbulence and user discomfort

Engineering Contradiction:
Improvevacuum cleaner sizeVSAvoidexhaust air speed
Core Design Contradiction:
Volume of moving objectVSSpeed

Solution Approach 1:

The receiving bay is positioned to extend over a corner of the housing, utilizing three-dimensional space efficiently. This corner positioning allows the exhaust opening to have a larger flow cross-section while maintaining a compact overall device volume, as the bay occupies space at the corner rather than requiring additional linear dimensions.

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

Solution Approach 2:

The receiving bay is designed as a diffuser with multiple outlet openings distributed across its surface. This segmentation of the exhaust flow into multiple smaller streams reduces the velocity of individual jets and minimizes dust turbulence, while the combined cross-sectional area of all outlets provides sufficient total flow capacity.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If a fixed exhaust system is used, then the structure is simple, but the device cannot switch between vacuum and blower functions

Engineering Contradiction:
Improveexhaust system structureVSAvoidfunction switching capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system allows dynamic reconfiguration of the exhaust path by enabling the user to remove the air filter insert and install a blow-out adapter instead. This simple dynamic change transforms the device between vacuum mode (with filter) and blower mode (with adapter), providing functional versatility without complex mechanical systems.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The receiving bay is designed as a universal interface that can accommodate both the air filter insert for vacuum operation and the blow-out adapter for blower operation. This single multi-functional receptacle eliminates the need for separate exhaust systems for different modes, maintaining structural simplicity while enabling function switching.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 results in a more compact and user-friendly dry vacuum cleaner with reduced exhaust air velocity, minimizing dust turbulence and discomfort, while allowing for versatile operation as both a vacuum and blower.

Implementation Method 1

the receiving bay is designed as a diffuser. A reduction in the outflow velocity of the exhaust air can thus already be achieved

Methodology Applied
Scientific EffectDiffuser: Diffusion

Implementation Method 2

the air filter insert has a frame with a plurality of filter openings. As a result, a linearization of the otherwise turbulent air flowing out of the receiving bay designed as a diffuser can be achieved

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3790437B1Air ejector system for a portable dry vacuum cleaning unit
Publication Date: 2023.07.12 HILTI AG
  • EP3790437B1 patent drawingFigure 1
  • EP3790437B1 patent drawingFigure 2
  • EP3790437B1 patent drawingFigure 3

AI summary

The invention relates to an air outlet system for a portable dry vacuum cleaner, via which the intake air sucked in by the dry vacuum cleaner can be expelled into the environment as exhaust air, wherein the air outlet system has an accommodation bay which is to be disposed in a housing of the dry vacuum cleaner and in which optionally an air cleaner cartridge or an exhaust adapter may be accommodated, with the exhaust adapter having an exhaust fitting onto which a blower hose connects and the air cleaner cartridge being free from an outlet fitting of this kind.