Variable Orifice Check Valve for Turbo Pump Back Pressure Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbo-molecular pumps in semiconductor processing chambers experience back pressure due to fore line pressure fluctuations, leading to vibrations and potential damage.
Innovation Solution
The implementation of variable orifice check valves with a flange, guide pins, a spring, and a movable plate, which self-adjust to changes in pressure to regulate line pressure and reduce back pressure on turbo-molecular pumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed orifice check valve is used, then the valve structure is simple, but the back pressure cannot be effectively reduced during pressure cycling
Solution Approach 1:
The check valve employs a movable plate that can dynamically adjust its position relative to the flange body. The plate is guided by guide pins and controlled by a spring mechanism, allowing the orifice opening to vary automatically in response to pressure changes. This dynamic adjustment enables effective back pressure reduction during pressure cycling while maintaining a relatively simple overall structure.
2Reliability
If the orifice size is increased to reduce back pressure, then back pressure reduction improves, but the valve cannot maintain stable operation during pressure cycling
Solution Approach 1:
The spring mechanism provides a feedback force that acts on the movable plate. When fore line pressure increases, the pressure differential moves the plate to increase the orifice opening, allowing more flow through and reducing back pressure. When pressure stabilizes or decreases, the spring returns the plate to its original position. This automatic feedback control maintains stable operation during pressure cycling while effectively managing back pressure.
3Stress or pressure
If a variable orifice check valve with movable plate and spring is implemented, then back pressure is reduced, but the device complexity increases
Solution Approach 1:
The check valve is divided into distinct functional components: a flange body with guide pin openings, guide pins that constrain movement, a spring that provides restoring force, and a movable plate with an orifice. This segmentation allows each component to perform its specific function independently while working together to reduce back pressure fluctuations, making the complex system manageable and maintainable.
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 variable orifice check valves effectively reduce back pressure fluctuations on turbo-molecular pumps, preventing damage and ensuring stable operation during pressure cycling.
Implementation Method 1
A spring is positioned around the elongate shaft of each guide pin
Data Source
AI summary
Variable orifice check valves comprising a flange with a guide pin, spring and movable plate are described. The flange has a body with at least one guide pin opening in the top surface. A guide pin is positioned within the at least one guide pin opening and a spring is positioned around the guide pin. The movable plate has an opening and slides along the guide pins with the spring between the top surface of the flange body and the bottom surface of the movable plate.