Actuator Rod Sealing via Third Fluid Barrier

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Solution Overview

Problem

Mechanical seals in adjustable inlet guide vane systems for compressors fail to effectively isolate control electronics from harsh environments, leading to ice formation and pressure imbalances due to cryogenic temperatures and hydraulic forces.

Innovation Solution

Implementing a fluid dynamic sealing mechanism where a third fluid with higher pressure than the actuator rod fluid is circulated between the actuator rod and body, preventing ice formation and balancing forces by using a neutral fluid to enhance sealing and prevent fluid mixing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical seals are used to isolate control electronics from the harsh environment, then the control electronics are protected, but ice formation occurs and sealing reliability deteriorates due to cryogenic temperatures

Engineering Contradiction:

Improvesealing reliabilityVSAvoidice formation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A fluid dynamic seal using a third fluid (different from the first and second fluids) is introduced as an intermediary substance between the actuator rod and the environment. This third fluid creates a pressurized barrier that prevents ice formation and blocks the actuator rod from direct thermal contact with the cryogenic environment, thereby eliminating the harmful thermal effect while maintaining sealing reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention employs a hydraulically pressurized third fluid circulating through a dedicated circuit to create a dynamic seal around the actuator rod. The pressurized fluid generates sufficient pressure to prevent ice formation and maintains thermal isolation, replacing the inadequate mechanical seal system with a pneumatic/hydraulic sealing mechanism that actively combats cryogenic conditions.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Reliability

If mechanical seals are used to separate fluids, then fluid isolation is achieved, but pressure imbalances and force inefficiencies occur due to hydraulic forces

Engineering Contradiction:

Improvefluid isolationVSAvoidforce efficiency

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The third fluid acts as a mediator between the first and second fluids, allowing effective fluid isolation without the pressure imbalances that plague mechanical seals. The intermediary fluid dynamically transmits and balances forces while maintaining strict fluid separation, eliminating force efficiency losses while preserving reliable isolation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention replaces the mechanical seal system with a fluid dynamic sealing system. This substitution eliminates the mechanical contact and associated friction, wear, and force imbalances, while achieving equivalent or superior fluid isolation through the pressurized third fluid that dynamically adapts to pressure differentials.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Force

If the actuator rod extends into the actuator device body for force transfer, then actuation is achieved, but thermal contact causes ice formation due to cryogenic temperatures

Engineering Contradiction:

Improveforce transferVSAvoidthermal contact

Core Design Contradiction:

ForceVSTemperature

Solution Approach 1:

The third fluid serves as a thermal intermediary between the actuator rod and the cryogenic environment. It allows the actuator rod to extend into the actuator device body for effective force transfer while simultaneously preventing direct thermal contact with cold surfaces, thereby blocking the heat transfer path that would otherwise cause ice formation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The pressurized third fluid creates an inert thermal environment around the actuator rod, isolating it from the cryogenic conditions. This inert fluid barrier prevents the actuator rod from reaching temperatures low enough to cause ice formation, while still permitting mechanical force transmission through the fluid-filled space.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

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 fluid dynamic sealing effectively prevents ice formation and balances forces, ensuring reliable operation of actuator systems in harsh environments by maintaining separation and controlling temperature and pressure.

Implementation Method 1

the chilled actuator rod 120, which extends inside the body of the actuator device 130 and is a good heat conductor, may determine ice formation

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The third fluid has a pressure larger than a pressure of the first fluid

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS9835169B2Actuator sealing system and method

Publication Date: 2017.12.05 NUOVO PIGNONE TECH SRL

AI summary

Actuator devices useable to change orientation of one or more vanes, including an actuator rod and an actuator device body configured to allow the actuator rod to move along the axis inside the actuator device body, and having an inlet flange configured to allow a third fluid to enter a space between the actuator device body and the actuator rod, and an outlet flange configured to allow the third fluid to exit the actuator device body. Besides providing a fluid seal between the first fluid and the second fluid, the third fluid may also heat the actuator rod thereby preventing ice formation.