Leak Detector Pumping System with Interstage Rough Vacuum Connection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing leak detectors face challenges in achieving low ultimate vacuum pressure while maintaining high pumping rates, robustness, and affordability, particularly due to aging rough vacuum pumps and background noise issues.
Innovation Solution
The leak detector configuration includes two rough vacuum pumps connected in parallel with their outlets between the pumping stages of each other, and a turbomolecular vacuum pump, allowing for enhanced pumping rates and reduced ultimate vacuum pressure, improving sensitivity and robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple rough vacuum pumps are connected in parallel to increase pumping rate, then the pumping rate is improved, but the ultimate vacuum pressure increases (worsens)
Solution Approach 1:
The pumping system is segmented into two functional groups: rough vacuum pumps (first group) responsible for high pumping rate at atmospheric pressure, and turbomolecular vacuum pumps (second group) responsible for achieving low ultimate vacuum pressure. The segmentation allows each group to optimize its performance for its specific function without compromising the other.
Solution Approach 2:
The patent introduces a temporal dimension to the pumping process by sequentially activating different pump groups at different pressure thresholds. The rough vacuum pumps operate first to rapidly reduce pressure, then turbomolecular pumps engage to achieve ultimate vacuum, creating a multi-stage temporal progression that resolves the contradiction between speed and final pressure.
2Measurement precision
If multiple pumping stages are connected in series to lower ultimate vacuum pressure, then the ultimate vacuum pressure is improved, but the pumping rate during evacuation deteriorates
Solution Approach 1:
The system dynamically switches between different pump configurations based on the current pressure level. At high pressure levels, the rough vacuum pumps provide high pumping rate. As pressure decreases below a threshold, the system transitions to turbomolecular pumps for ultimate vacuum. This dynamic adaptation resolves the contradiction by optimizing for pumping rate when needed and for ultimate pressure when achievable.
3Measurement precision
If an additional turbomolecular vacuum pump is inserted between the main turbomolecular pump and rough vacuum pump, then the ultimate vacuum pressure is improved, but the cost and complexity increase
Solution Approach 1:
The turbomolecular vacuum pumps are designed to serve multiple functions: they act as both the primary high-vacuum pumps and serve as a buffer stage to protect the main turbomolecular pump from repeated air inlets. This multi-functionality eliminates the need for an additional dedicated turbomolecular pump, reducing complexity while maintaining performance.
Solution Approach 2:
The second turbomolecular pump group serves itself by absorbing the repeated air inlets that would otherwise damage the main turbomolecular pump. This self-protective mechanism eliminates the need for external protection systems or additional pumps, reducing overall system complexity while maintaining reliability.
4Measurement precision
If the number of rough vacuum pump stages is increased to lower ultimate vacuum pressure, then the ultimate vacuum pressure is improved, but the device complexity and cost increase
Solution Approach 1:
Instead of adding more stages to existing rough vacuum pumps, the patent uses a second group of turbomolecular pumps that replicate the vacuum-creating function at a different operational level. These pumps copy the essential function of achieving low pressure but operate in a regime where they are more efficient and less complex than would be required to achieve the same result by adding rough pump stages.
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 configuration achieves a significant reduction in ultimate vacuum pressure, enhancing measuring sensitivity and robustness against pump aging, while maintaining pumping performance and cost-effectiveness.
Implementation Method 1
a first rough vacuum pump (5), at least one second rough vacuum pump (6)... The inlets (12, 14) of the rough vacuum pumps (5, 6) being connected in parallel to the detection inlet (2)
Implementation Method 2
a turbomolecular vacuum pump (7) having an outlet connected between the first isolation valve (8) and the inlets (12, 14) of the rough vacuum pumps (5, 6)
Implementation Method 3
a detection inlet (2) for connecting to an object to be tested... a gas detector (4) connected to the turbomolecular vacuum pump (7)
Data Source
AI summary
A leak detector for checking the sealing tightness of an object to be tested includes a detection inlet to be connected to the object, a first pumping device, and a gas detector. The first pumping device includes a first rough vacuum pump, at least one second rough vacuum pump, and a turbomolecular pump. The gas detector is connected to the turbomolecular pump. The outlet of the at least one second rough vacuum pump is connected to the first rough vacuum pump, between two in-series pumping stages of the first rough vacuum pump.