Spiral Screw Shield for Vacuum Cell Contamination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vacuum measuring cells, particularly diaphragm cells, face contamination issues due to process gases and residual gases, leading to inaccurate measurements and drift behavior, which cannot be fully eliminated by cleaning, affecting precision and reproducibility.
Innovation Solution
A screw shield arrangement with spiral-form convolutions is implemented between the vacuum measuring cell and the process chamber, preventing direct through-view and forcing particles to interact multiple times with the shield before reaching the cell, thereby reducing contamination and enhancing the shield's protective effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a flat shield is used to block direct particle paths, then service life is improved, but measurement precision deteriorates due to scattered particles reaching the diaphragm
Solution Approach 1:
The patent applies a spiral-shaped shield instead of a flat shield. The spiral geometry creates multiple reflections and longer particle paths, effectively blocking scattered particles from reaching the diaphragm while maintaining protection. This curved/spiral configuration resolves the contradiction by improving both service life and measurement precision compared to flat shields.
Solution Approach 2:
The patent transitions from a two-dimensional flat shield to a three-dimensional spiral structure. This dimensional change allows the shield to block particles not only from direct paths but also from scattered trajectories, thereby improving measurement precision while maintaining the protective function for service life.
2Measurement precision
If the diaphragm is made thinner to increase sensitivity, then measurement sensitivity is improved, but contamination impact worsens leading to more errors
Solution Approach 1:
The spiral shield acts as an intermediary between the process chamber and the diaphragm. It blocks contaminants before they can reach the thin diaphragm, thereby protecting the sensitive component while allowing the diaphragm to maintain its thin configuration for high sensitivity measurements.
Solution Approach 2:
The spiral geometry of the shield creates multiple interaction points for particles, increasing the likelihood that contaminants will be blocked or redirected away from the diaphragm. This enhances protection for the thin diaphragm while preserving measurement sensitivity.
3Duration of action of stationary object
If a shield is added to protect the vacuum cell, then service life is improved, but device complexity increases
Solution Approach 1:
The spiral shield provides enhanced protection compared to flat shields while maintaining a relatively simple single-component structure. The spiral geometry achieves superior particle blocking without requiring multiple shields or complex assemblies, thus improving service life with minimal increase in device complexity.
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 screw shield significantly increases the service life of vacuum measuring cells by minimizing contamination, ensuring high precision and reproducibility of measurements while being economical and easy to clean.
Implementation Method 1
the shield 7 is to deploy its protective effect thereby that the undesirable gases or particles are condensed on the shield surface such that they do not reach into the vacuum cell
Implementation Method 2
a gas throughflow between the outer diameter of the thread flank and the inner wall is inhibited and this throughflow is substantially forced into the spiral-form thread pitch
Data Source
AI summary
A shield arrangement for a vacuum measuring cell has a tubular shield housing encompassing a shield and an exit port for connection to a vacuum measuring cell and a connection opening for the object space to be measured. The shield is between the two openings and is implemented as a screw shield with spiral convolutions, its thread flange in the outer diameter being in contact on the inner wall of the shield housing such that a gas throughflow between the outer diameter of the thread flange and the inner wall is inhibited and is substantially forced into the spiral thread flight, and the exit port is on one side of the tubular section and the connection opening is on the other, opposite side and the screw shield is implemented such that in the axial line of vision the shield arrangement between the two openings is optically tight.