Movable Ring Sealing Device for Rotating Machine Shutdown
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Solution Overview
Problem
Rotating machines face challenges in effectively confining pressurized fluids when stopped, as existing sealing systems become unreliable and prone to leaks due to thermal expansions and pressure imbalances, especially when the rotor is stationary.
Innovation Solution
A sealing device with a movable ring axially guided in a static structure, activated externally when the machine is stopped, uses elastomeric seals and a control fluid to maintain separation between environments, preventing fluid leakage by displacing a front sealing gasket to contact the rotor disk, ensuring effective confinement without moving machine components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rotor shaft is made axially movable to engage sealing gaskets during shutdown, then fluid confinement during shutdown is improved, but the complexity of the sealing system increases
Solution Approach 1:
The patent applies dynamics by making the ring movable rather than fixed. This allows the sealing system to adapt its configuration based on operational state (running vs. shutdown), optimizing performance for each condition without requiring complete redesign of the sealing architecture
Solution Approach 2:
The patent uses pneumatic/hydraulic principles by introducing control fluid to actuate the movable ring. This allows complex positioning and sealing actions to be achieved through fluid pressure rather than complex mechanical linkages, reducing overall system complexity
2Device complexity
If existing sealing systems are used without additional control mechanisms, then the device complexity is minimized, but the ability to prevent fluid leakage during shutdown deteriorates
Solution Approach 1:
The patent applies self-service by designing the movable ring to automatically respond to shutdown conditions through control fluid pressure. The system serves itself by using the pressure differential that naturally occurs during shutdown to actuate the sealing action, without requiring external control systems or complex actuation mechanisms
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 solution ensures reliable confinement of pressurized fluids within the stator part of rotating machines during both operating and non-operating conditions, preventing leaks and allowing for seal replacement without exposing the internal pressurized environment to the outside.
Implementation Method 1
supplying a control fluid under pressure from the outside to a chamber on the back of the ring
Implementation Method 2
each seal being formed by an elastomeric ring
Data Source
AI summary
A fluid sealing device for rotating machines having a rotor part including at least one disk carried by a rotating shaft rotating in and relatively to a stator part in the presence of a fluid is disclosed. The rotating shaft has a sealing system defining a first environment at a first pressure. The stator part has a wall in front of the disk of the stator part defining a second environment therewith containing a fluid at a second pressure. The device includes a movable ring placed between the wall of the stator part and the disk of the rotor part and has a front sealing gasket facing towards the disk. The movable ring is moved in the active position when the rotating machine is stopped to prevent the fluid passage from one environment to the other.