Capillary Metering Device with Non-Circular Cross-Section
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing capillary metering devices for powders face challenges in achieving precise and reliable metering due to the need for precise adaptation to powder properties, clogging issues, and unpredictable flow and adhesion properties caused by non-uniform surface roughness and circular cross-sections, limiting flow rates and complicating cleaning and product changes.
Innovation Solution
A capillary metering device with a vibration body formed by multiple adjoining parts, allowing for a channel with an open side in the demounted state to be machined and coated, providing a clearly defined cross-section and surface properties, enabling precise and reliable powder flow control and easy cleaning, with the option for non-round cross-sections and parallel channels for increased flow rates and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a circular cross-section capillary is used, then the structure is simple and easy to manufacture, but the adhesion and flow properties are difficult to control and predict
Solution Approach 1:
The patent changes the capillary cross-section from circular to non-circular (rectangular, triangular, or trapezoidal). This asymmetric shape modification allows for defined wall angles and consistent surface properties, making adhesion and flow properties predictable and controllable while maintaining manufacturing feasibility through standard machining processes.
2Reliability
If the capillary cross-section is made smaller, then the adhesion forces increase and powder flow stops when vibration is off, but the flow rate becomes too low for practical metering
Solution Approach 1:
The patent modifies the capillary cross-sectional geometry parameters (changing from circular to non-circular with specific wall angles between 30° and 60°). This parameter change allows for larger cross-sectional areas while maintaining sufficient adhesion forces through optimized surface contact, thereby increasing flow rates to practical metering ranges (0.1 mg/s to 1 g/s) while preserving reliable flow control.
3Productivity
If the capillary cross-section is made larger, then the flow rate increases, but the cohesion forces are insufficient to stop the powder flow when vibration is switched off
Solution Approach 1:
The non-circular cross-section with specific wall angles creates asymmetric contact between powder particles and capillary walls. This asymmetry enhances adhesion forces through increased surface contact area and optimized force distribution, allowing larger cross-sections to maintain sufficient cohesion forces for reliable flow stopping while enabling higher productivity.
4Device complexity
If a stationary capillary is used, then the structure is simple, but powder flow cannot be generated without vibration excitation
Solution Approach 1:
The patent incorporates a vibration body that mechanically excites the capillary at controlled frequencies and amplitudes. This vibration overcomes powder cohesion forces to enable continuous flow during operation, while the optimized non-circular cross-section ensures flow can be reliably stopped when vibration ceases, achieving practical metering productivity.
5Ease of manufacture
If the capillary is formed as a single integrated part, then manufacturing is simple, but cleaning and product change are difficult due to minimal cross-section
Solution Approach 1:
The patent divides the metering device into separable components: a removable capillary assembly and a stationary housing. The capillary can be detached and replaced independently, enabling easy cleaning and product changes without disassembling the entire device, while the capillary itself remains a simple machined component for ease of manufacture.
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 solution enables precise and reliable metering with a wider range of flow rates (0.1 mg/s to 1 g/s) and allows for easy cleaning and aseptic applications, improving the adaptability to different powder properties and container geometries.
Implementation Method 1
the vibration body is excited to perform vibrations with a suitable frequency and amplitude, the cohesive forces are overcome
Implementation Method 2
the powder, as a result of its cohesive properties, cannot pass through the stationary capillary but remains adhered thereto
Data Source
AI summary
A capillary metering device for a powder product has a vibration body with a capillary formed within the vibration body for receiving and conveying the powder product. The vibration body is formed of at least two adjoining body parts, wherein the capillary is formed as a channel with at least one open side in the demounted state in at least one of the body parts. The open side of the channel in the mounted state is closed off by the adjoining body part. The vibration body is caused to vibrate with such an amplitude and frequency that a powder flow of the powder product passes through the capillary formed in the vibration body into a target container and that upon reaching a target quantity of the powder product in the target container the powder flow to the target container is interrupted.