Valve Sequencing for Pump Pressure Fluctuation Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current multi-stage pumps cause sharp pressure spikes in fluids during semiconductor manufacturing, leading to defects such as outgassing, bubble formation, and premature polymer crosslinking, which can damage sensitive chemicals and result in uneven coatings.
Innovation Solution
Implementing a valve sequencing method that minimizes pressure fluctuations by avoiding the creation of closed spaces and ensuring valves are opened or closed only when necessary, with exterior valves opening before interior ones and sufficient time allowed for valve changes to prevent pressure spikes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If valves are opened and closed rapidly to increase pumping speed, then productivity improves, but pressure spikes increase causing fluid damage and coating defects
Solution Approach 1:
The system performs preliminary actions by opening exterior valves before interior valves and closing interior valves before exterior valves. This predetermined sequencing prepares the fluid path in advance to prevent pressure trapping, allowing faster operation without causing pressure spikes that would damage the fluid or cause coating defects.
Solution Approach 2:
The valve system is segmented into interior valves and exterior valves with distinct sequencing rules. Interior valves (within the pump housing) are controlled separately from exterior valves (outside the pump housing), allowing independent timing control that prevents simultaneous closure that would trap pressure while maintaining high pumping speed.
2Productivity
If valves are closed to create sealed chambers for pumping, then pumping efficiency improves, but pressure variations increase causing outgassing and bubble formation
Solution Approach 1:
Before closing any valve that would create a sealed chamber, the system preliminarily opens vent valves to maintain pressure equilibrium. This preliminary action prevents pressure buildup that would cause outgassing and bubble formation, while still allowing the sealed chambers to function for efficient pumping.
Solution Approach 2:
Vent valves act as intermediary elements between the sealed pumping chambers and the external environment. These intermediaries provide a controlled pressure release path that prevents harmful pressure variations while allowing the sealed chambers to maintain their pumping efficiency.
3Reliability
If valve operation time is extended to ensure proper sealing, then reliability improves, but cycle time increases reducing productivity
Solution Approach 1:
The system performs preliminary valve operations in a predetermined sequence that ensures proper sealing is achieved before the main pumping action begins. By opening exterior valves first and closing interior valves first, the system establishes reliable sealing conditions in advance, allowing the main pumping cycle to proceed at full speed without extended timing.
Solution Approach 2:
The valve sequencing maintains continuous useful action by overlapping valve transition periods with pumping cycles. The predetermined sequence ensures that valves are always in the correct state for the current phase of operation, eliminating idle time while maintaining reliable sealing throughout the continuous pumping process.
Data Source
AI summary
Systems and methods for minimizing pressure fluctuations within a pumping apparatus are disclosed. Embodiments of the present invention may serve to reduce pressure variations within a fluid path of a pumping apparatus by avoiding closing a valve to create a closed or entrapped space in the fluid path and similarly, avoiding opening a valve between two entrapped spaces. More specifically, embodiments of the present invention may serve to operate a system of valves of the pumping apparatus according to a valve sequence configured to substantially minimize the time the fluid flow path through the pumping apparatus is closed (e.g. to an area external to the pumping apparatus).