Study on the Pumping Performance and Structure Parameters Optimization of High-Speed Small Compound Molecular Pump

Area of Science:

• Mechanical Engineering
• Vacuum Technology
• Analytical Instrumentation

Background:

• Existing molecular pumps for portable mass spectrometers are bulky and heavy, limiting device miniaturization.
• Miniaturization constraints (1.8 kg mass, 25 mm exhaust) pose challenges for pump strength and performance.
• Current designs often combine vertical bleed and compression channels, leading to suboptimal performance.

Purpose of the Study:

• To develop a miniaturized compound molecular pump with enhanced pumping performance for portable mass spectrometers.
• To address the limitations of existing molecular pump designs regarding mass, volume, and efficiency.
• To optimize the structural parameters of a novel compound molecular pump for improved flow rate and compression ratio.

Main Methods:

• Proposed a compound molecular pump integrating horizontal bleed and multi-stage spiral compression channels.
• Developed an aerodynamic model using the test particle Monte Carlo method for performance simulation in a thin air environment.
• Employed the NNIA multi-objective optimization algorithm to refine structural parameters.

Main Results:

• Optimized compound molecular pump design achieved a 13.6% increase in maximum flow rate.
• Achieved a 41.6% enhancement in the compression ratio after structural parameter optimization.
• Aerodynamic model predictions showed high accuracy, with experimental data exhibiting a 12-27% error.

Conclusions:

• The novel compound molecular pump design effectively enhances performance under miniaturization constraints.
• The validated aerodynamic model provides a reliable tool for designing and optimizing high-speed, small molecular pumps.
• Optimized pump parameters pave the way for broader adoption and advancement of portable mass spectrometers.