Multi-Stage Vacuum Pump Inter-Stage Coupling Recirculator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-stage vacuum pumps face issues where gas buildup on the exhaust side of a stage can cause stress on the rotor due to excessive gas being exhausted by one stage than can be handled by the subsequent stage, leading to pressure imbalances.
Innovation Solution
An inter-stage coupling with a recirculator is introduced to fluidly couple the outlet aperture with the inlet aperture, allowing recirculation of built-up gas from one stage to another, reducing the strain on the rotor and minimizing complexity by housing the recirculator within the coupling, which also protects it from cooler ambient conditions and potential condensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a multi-stage vacuum pump is used to evacuate devices, then the complete compression range from vacuum to atmospheric pressure is achieved, but gas can build up on the exhaust side of a stage causing stress on the rotor
Solution Approach 1:
A recirculation conduit is introduced as an intermediary pathway between the exhaust side and inlet side of the same stage. This mediator allows excess gas to bypass the rotor directly, preventing pressure buildup that would otherwise stress the rotor while maintaining the multi-stage compression functionality
Solution Approach 2:
The pump stage serves itself by recirculating its own excess exhaust gas back to its inlet side. The recirculation system enables the stage to regulate its own pressure balance without external intervention, preventing rotor stress through self-regulation of gas flow
2Device complexity
If the recirculator is housed within the inter-stage coupling, then the arrangement becomes compact and self-contained, but the recirculator is exposed to elevated temperatures that may cause condensation
Solution Approach 1:
The elevated temperature environment within the inter-stage coupling, which initially appears harmful due to condensation risk, is actually beneficial as it prevents condensation of solid materials from the pumped medium. The thermal energy that could be considered a harmful factor is converted into a protective feature against material deposition
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 solution effectively reduces the pressure imbalance across the rotor, prevents damage from gas buildup, and maintains a compact pump design by recirculating excess gas, thus enhancing the operational stability and efficiency of multi-stage vacuum pumps.
Implementation Method 1
a pressure-actuated valve actuatable to couple the recirculation inlet aperture with the recirculation outlet aperture in response to a selected pressure differential between the recirculation inlet aperture and the recirculation outlet aperture
Implementation Method 2
The valve may be configured so that the member is displaced by a translation movement... The recirculation inlet aperture and the recirculation outlet aperture may then be fluidly coupled when the pressure differential is greater than the selected or predetermined pressure differential
Data Source
Figure 1A~1B
Figure 2~3
Figure 4~5
AI summary
An inter-stage coupling for a multi-stage vacuum booster pump, a vacuum pump and a method are disclosed. The inter-stage coupling for a multi-stage vacuum pump comprises: a first coupling face configured to be received by a first adjacent stage of the multi-stage vacuum pump; a second coupling face configured to be received by a second adjacent stage of the multi-stage vacuum pump; and a recirculator comprising a recirculation inlet aperture formed in the first coupling face, a recirculation outlet aperture formed in the first coupling face, and a recirculation conduit having a recirculation valve configured to selectively fluidly couple the recirculation inlet aperture with the recirculation outlet aperture. In this way, the pressure in a stage can be relieved by fluidly coupling the outlet aperture with the inlet aperture in order to recirculate built-up gas from one part of the first stage pump to another part of the first stage pump in order to reduce the strain on the rotor.