Vacuum Cleaner Filter Pressure Sensing for Accurate Clog Detection
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Solution Overview
Problem
Existing vacuum cleaners fail to accurately determine when the filter is clogged due to the influence of connected work tools and accessories, leading to premature filter cleaning and inability to differentiate between filter occupancy and pressure losses caused by small power tools with small suction cross-sections.
Innovation Solution
The implementation of pressure sensors to measure pressure differences before and after the filter, allowing for reliable detection of filter clogging and automatic or manual initiation of filter cleaning, along with the use of absolute and differential pressure sensors to differentiate between filter contamination and pressure losses from connected devices, enabling adaptive engine speed control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pressure measurement is used to determine filter clogging, then filter cleaning can be triggered, but connected work tools with small suction cross-sections cause false positives leading to premature cleaning
Solution Approach 1:
The pressure measurement system is segmented into multiple measurement points: one before the filter and one after the filter. This segmentation allows differential pressure measurement that specifically isolates filter clogging effects from other pressure losses in the system, such as those caused by connected work tools with small suction cross-sections.
Solution Approach 2:
A differential pressure sensor is introduced as an intermediary measurement device that directly measures the pressure difference across the filter. This intermediary approach eliminates the need to infer filter status from total system pressure, providing accurate filter clogging detection independent of connected device characteristics.
2Productivity
If filter cleaning is triggered based on total pressure loss, then filter maintenance is initiated, but connected devices with small flow cross-sections cause unnecessary cleaning operations
Solution Approach 1:
The pressure measurement is segmented to distinguish filter-related pressure loss from device-related pressure loss. By measuring pressure specifically across the filter rather than total system pressure, the system avoids triggering unnecessary cleaning operations when connected devices with small flow cross-sections are used.
Solution Approach 2:
The system uses feedback from differential pressure sensors to intelligently control filter cleaning operations. The controller continuously monitors the pressure difference across the filter and only triggers cleaning when the differential pressure exceeds a threshold indicating actual filter clogging, preventing unnecessary cleaning during normal operation with small devices.
3Adaptability or versatility
If a single pressure sensor measures total pressure loss, then system status can be monitored, but filter occupancy cannot be differentiated from device-induced pressure losses
Solution Approach 1:
The pressure monitoring system is segmented into two distinct measurement locations: upstream of the filter and downstream of the filter. This segmentation enables the differential pressure sensor to isolate filter contamination effects from other system variables, providing precise filter status monitoring while maintaining overall system adaptability.
Solution Approach 2:
A differential pressure sensor serves as an intermediary measurement device that directly measures the pressure gradient across the filter. This intermediary approach provides specific filter contamination information without being influenced by connected device characteristics, enhancing both measurement precision and system versatility.
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
Ensures filter cleaning only when necessary, prevents malfunctions, and optimizes engine speed based on connected device performance, improving the accuracy and efficiency of filter maintenance and suction capacity.
Implementation Method 1
the pressure in the flow space before and in the flow space after the filter is detected with the pressure sensor via the measuring points. The pressure difference between the pressures in the two flow chambers increases with increasing clogging of the filter
Implementation Method 2
The filter can be cleaned with the help of a vibrating device, with which the filter is set in vibrating motion for filter cleaning. The shaking movements cause the suction material adhering to the filter to fall off
Implementation Method 3
it is also possible to achieve filter cleaning by directing an air flow through the filter in the opposite direction to the suction flow. This flow of air flows from the inside to the outside of the filter and thereby detaches the suction material adhering to the outside of the filter
Data Source
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AI summary
The device has flow chambers e.g. dust collecting chambers (2, 10), provided with measuring points (12, 13) and connected to pressure sensors e.g. differential pressure sensors (15), which are signal-connected to a controller. The controller sends a signal when difference between pressures (P1, P2) in the flow chambers reaches a threshold value. A warning apparatus (22) obtains a control signal, and comprises an optical and/or acoustic warning element e.g. warning lamp or horn.