Spherical Throttle Valve for Cryogenic Sealing
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Solution Overview
Problem
Rocket engine fluid control systems face challenges in reducing cost, weight, and size while maintaining accurate regulation and reliable stop functions, especially when handling cryogenic fluids, due to the limitations of existing valve designs and materials.
Innovation Solution
A valve device with a throttle element and annular sealing gasket, where the internal cavity is spherical, allowing for precise regulation and reliable stop functions with a single component, reducing the need for additional control interfaces and electronics, and using materials like PTFE or Vespel for sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single valve device is used for both regulation and stop functions, then device complexity and weight are reduced, but achieving reliable sealing in the fully-closed position becomes more difficult
Solution Approach 1:
The patent combines the regulation function and stop function into a single valve device. The throttle element with its variable opening serves for regulation, while the same element in its fully-closed position provides the stop function. This merging eliminates the need for separate regulation and stop valves, reducing device complexity and weight while maintaining reliable sealing through the spherical cavity design that ensures complete gasket contact.
Solution Approach 2:
The patent employs a spherical internal cavity in the throttle element that receives an annular sealing gasket. The spherical geometry ensures that when the valve is in the fully-closed position, the entire circumference of the gasket makes contact with the cavity wall, providing reliable sealing. This curved surface design is particularly effective for cryogenic applications where material contraction occurs.
2Ease of manufacture
If traditional sealing materials are used, then ease of manufacture is improved, but sealing performance in cryogenic conditions deteriorates
Solution Approach 1:
The patent specifies sealing gaskets made from materials such as PTFE (polytetrafluoroethylene) or Vespel (polyimide) that are specifically suited for cryogenic temperatures. These materials maintain their sealing properties at low temperatures where traditional materials would become brittle or lose elasticity. The spherical cavity design also adapts to thermal contraction, maintaining sealing contact across temperature variations.
3Manufacturing precision
If the throttle element has a long stroke for accurate regulation, then manufacturing precision requirements are reduced, but the valve occupies more volume
Solution Approach 1:
The patent utilizes rotational movement of the throttle element around a central axis to achieve regulation. The variable opening is formed by the interaction between the throttle element's peripheral opening and the duct, allowing precise flow control through angular positioning rather than linear displacement. This rotational approach enables accurate regulation with a compact stroke length, reducing the volume occupied by the valve device.
Data Source
AI summary
The invention relates to a valve device comprising a valve body defining a fluid flow duct having a throttle element disposed therein and turned about its axis by actuator means via a drive shaft, the throttle element having an internal cavity defined by a circular wall that is open in its bottom portion. The circular wall also presents, over a portion of its periphery, an opening of varying shape so as to define a fluid flow passage in the duct that is variable between a fully-open position in which the opening co-operates in full with the duct, and a fully-closed position in which said circular wall closes the duct. The device further includes an annular sealing gasket disposed in the flow duct, said gasket being in contact with the wall of the internal cavity in the throttle element. The internal cavity of the throttle element is spherical in shape so that in the fully-closed position of the valve, the entire circumferential of the sealing gasket is in contact with the wall of the internal cavity of the throttle element.