Vacuum Cleaner Filter Cleaning Using Pressure Differential Feedback

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Solution Overview

Problem

Existing vacuum cleaning devices are inefficient in automatically detecting and cleaning the filter element's degree of contamination, leading to insufficient cleaning and disruption of the suction process.

Innovation Solution

A method utilizing pressure sensors positioned upstream and downstream of the filter element to measure pressure differences, triggering cleaning when predetermined thresholds are reached, and switching off the device when excessive contamination is detected, ensuring efficient filter element cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If automatic filter element cleaning is performed based on pressure difference detection, then the suction process can be maintained, but the cleaning effectiveness is insufficient and the filter element is not adequately cleaned

Engineering Contradiction:
Improvesuction process continuityVSAvoidcleaning effectiveness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control device continuously monitors the pressure difference between upstream and downstream of the filter element and uses this feedback to determine when cleaning is needed. After cleaning, the system measures the pressure difference again and compares it with reference values to verify cleaning effectiveness, creating a closed-loop feedback system that ensures reliable cleaning while maintaining continuous operation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system determines a first pressure reference value before cleaning begins and a second pressure reference value after cleaning completes. By comparing the actual pressure difference against these pre-established reference values, the system can proactively determine when cleaning is needed and verify when cleaning is sufficient, preventing suction disruption before it occurs

Inventive Principle:
Principle #10Preliminary action

2Extent of automation

If pressure sensors are used to detect filter contamination, then automatic cleaning can be triggered, but the cleaning may not be sufficient to restore adequate suction

Engineering Contradiction:
Improveautomatic cleaning detectionVSAvoidcleaning quality
Core Design Contradiction:
Extent of automationVSManufacturing precision

Solution Approach 1:

The control device measures the pressure difference before cleaning (first pressure difference) and after cleaning (second pressure difference). It compares these measurements against reference values to verify that cleaning has restored the filter to an acceptable state. This feedback mechanism ensures that cleaning is not just triggered automatically but also verified to be effective

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system continues the suction process even when the filter element is slightly contaminated, as long as the pressure difference remains below the first threshold value. This partial action approach allows the system to operate with marginally reduced performance rather than stopping completely, while still maintaining adequate suction through periodic cleaning

Inventive Principle:
Principle #16Partial or excessive action

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 approach ensures effective cleaning of the filter element, maintaining a sufficient suction process by determining and addressing contamination levels through pressure differential measurements.

Implementation Method 1

a first pressure sensor for determining a first pressure value upstream of the filter element

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 2

a second pressure sensor positioned downstream of the filter element for determining a second pressure value

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 3

a turbine for sucking in an air flow through the filter element

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3727120B1Efficient filter cleaning
Publication Date: 2021.04.07 HILTI AG
  • EP3727120B1 patent drawingFigure 1
  • EP3727120B1 patent drawingFigure 2
  • EP3727120B1 patent drawingFigure 3

AI summary

The invention relates to a method for operating a vacuum cleaning device having a filter element, a filter element cleaning device, a control device, a turbine, as well as a first and a second pressure sensor, wherein the first pressure sensor is positioned upstream of the filter element in the flow direction for determining a first pressure value, and the second pressure sensor is positioned downstream of the filter element in the flow direction for determining a second pressure value. The method comprises the following method steps: operating the vacuum cleaner device for suctioning the air flow through the filter element; determining a first pressure reference value according to the first pressure value relative to the second pressure value; measuring the pressure difference between the first and second pressure value; cleaning the filter element using the filter element cleaning device, if the value of the pressure difference between the first and second pressure values reaches a first threshold value; determining a second pressure reference value according to the first pressure value relative to the second pressure value after the cleaning of the filter element has finished; determining a difference value between the second and first pressure reference values; and cleaning the filter element if the difference value between the second and first pressure reference values reaches a second threshold value, or switching off the vacuum cleaner device if the difference value between the second and first pressure reference values reaches a third threshold value. The invention also relates to a vacuum cleaner device for carrying out the method.