Vacuum System Booster Pump Segmentation for Viscous Flow
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Solution Overview
Problem
Existing vacuum systems, such as mass spectrometer systems, face challenges in maintaining high sample flow rates without significantly increasing power requirements, particularly in vacuum chambers operating in non-molecular or viscous flow regimes greater than 1 mbar, where traditional differential pumping arrangements are inefficient.
Innovation Solution
The integration of a booster pump in series with a primary pump, along with turbomolecular secondary pumps, enhances pumping capacity and reduces power consumption by configuring the primary and booster pumps to achieve synergy, allowing for efficient differential pumping of multiple vacuum chambers without increasing the number of pumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional differential pumping arrangements are used in vacuum chambers operating in non-molecular or viscous flow regimes greater than 1 mbar, then the system structure is simple, but the sample flow rates are insufficient and power requirements increase significantly
Solution Approach 1:
The vacuum pumping system is segmented into multiple functional units: a primary pump for rough pumping and backing, a booster pump specifically for viscous flow regimes, and secondary pumps for high vacuum. This segmentation allows each pump to operate in its optimal pressure range, with the booster pump specifically addressing the viscous flow regime gap that traditional single-stage systems cannot efficiently handle.
Solution Approach 2:
The booster pump acts as an intermediary device between the primary pump and secondary pumps. It receives gas flow from the primary pump in the viscous flow regime and delivers it to the secondary pumps, effectively bridging the pressure gap and enabling efficient sample flow without requiring the primary pump to operate inefficiently at low pressures or the secondary pumps to handle high pressure loads.
2Productivity
If the number of pumps is increased to enhance pumping capacity, then sample gas flow increases, but the power requirement and physical size of the system increase significantly
Solution Approach 1:
The booster pump is designed with multi-functionality, serving both as a primary pump for viscous flow regimes and as a backing pump for secondary pumps. This eliminates the need for separate dedicated pumps for each function, reducing the total pump count while maintaining adequate pumping capacity across different pressure regimes.
Solution Approach 2:
The system utilizes parameter changes in pump performance characteristics by selecting pumps optimized for specific pressure ranges. The booster pump is specifically chosen for its superior performance in viscous flow regimes, and its operating parameters are optimized to match the intermediate pressure requirements, allowing efficient operation without adding excessive system complexity.
3Reliability
If primary pumps are configured to back secondary pumps effectively, then high vacuum is achieved, but the compression ratio requirements become excessively high
Solution Approach 1:
The compression function is segmented across multiple pumps operating in series. The primary pump handles the initial compression from atmospheric pressure to intermediate vacuum levels, the booster pump provides additional compression in the viscous flow regime, and secondary pumps achieve final high vacuum. This segmentation distributes the total compression ratio requirement across multiple stages, preventing any single pump from requiring excessively high compression ratios.
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 increases sample flow rates and enables differential pumping of additional chambers while maintaining reduced power requirements and physical size, improving overall system performance in viscous pressure regimes.
Implementation Method 1
The secondary pumps may be turbomolecular pumps... As the secondary pumps are molecular pumps and cannot exhaust to atmosphere
Implementation Method 2
particularly in vacuum chambers having non-molecular, or viscous, flow regimes greater than about 1 mbar
Data Source
Figure 1~2
AI summary
The invention provides a vacuum system (12) comprising a plurality of vacuum chambers (14, 16, 18, 20) connected in series and a vacuum pumping arrangement (10) for differential pumping the chambers. The vacuum pumping arrangement comprises a primary pump (22) having an inlet (23) connected for pumping a first vacuum chamber (14) and an outlet (25) for exhausting at or around atmosphere, a booster pump (24) having an inlet (27) connected for pumping a second vacuum chamber (16) and an outlet (29) connected to the inlet (23) of the primary pump; and a secondary pump (26, 28) having an inlet (31, 33) connected for pumping a third vacuum chamber (18, 20) and an outlet (35, 37) connected to the inlet (27) of the booster pump.