Tie Bolt Venting Sealing Arrangement for Turbomachine Rotor Leakage

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing rotor structures in turbomachinery lack features to monitor incipient leakage of process fluid about the tie bolt and convey a sealing fluid effectively, leading to potential escape of hazardous fluids to the atmosphere.

Innovation Solution

Implementing a venting/sealing arrangement with annular seals and conduits through the stub shaft to monitor and manage incipient leakage, using a dry fluid seal system for sealing fluid conveyance and venting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional rotor structures with tie bolts are used, then structural simplicity is maintained, but incipient leakage cannot be monitored and hazardous fluids may escape to the atmosphere

Engineering Contradiction:
Improvesealing reliabilityVSAvoidventing/sealing arrangement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The rotor structure is segmented by introducing separate venting and sealing systems within the tie bolt assembly. The venting system includes separate conduits that divide the internal space into process fluid side and atmospheric side, enabling independent monitoring of leakage paths without compromising the overall structural integrity of the tie bolt.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A sealing fluid is introduced as an intermediary substance in the venting/conduit system. This sealing fluid acts as a mediator between the process fluid and the atmosphere, creating a fluid barrier that prevents hazardous fluid escape while allowing the system to maintain structural simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Difficulty of detecting and measuring

If annular seals and conduits are added to the tie bolt, then incipient leakage monitoring capability is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveincipient leakage detectionVSAvoidtie bolt manufacturing
Core Design Contradiction:
Difficulty of detecting and measuringVSEase of manufacture

Solution Approach 1:

The venting and sealing systems are nested within the existing tie bolt structure. The conduits are positioned concentrically or adjacently within the tie bolt, and annular seals are installed in circumferential grooves, allowing the monitoring functionality to be integrated without requiring complete redesign of the tie bolt manufacturing process.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

Rather than modifying the entire tie bolt structure, the invention applies local modifications at specific critical locations. Annular seals are placed at the interface between the process fluid and atmospheric sides, and venting conduits are positioned only where needed for leakage detection, minimizing manufacturing complexity while achieving effective monitoring.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If sealing fluid is conveyed through conduits, then process fluid leakage prevention is improved, but system complexity and fluid management requirements increase

Engineering Contradiction:
Improveprocess fluid leakageVSAvoidsealing fluid conveyance system
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The sealing fluid system is designed to be self-regulating and self-contained within the tie bolt structure. The conduits and annular seals work together to automatically maintain the fluid barrier without requiring external control systems, reducing overall system complexity while effectively preventing process fluid leakage.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4093975B1Rotor structure for a turbomachine with venting/sealing arrangement in tie bolt
Publication Date: 2025.04.02 SIEMENS ENERGY GLOBAL GMBH & CO KG
  • EP4093975B1 patent drawingFigure 1
  • EP4093975B1 patent drawingFigure 2~3
  • EP4093975B1 patent drawingFigure 4~5

AI summary

Rotor structure for a turbomachine, such as a centrifugal compressor is provided. Disclosed embodiments make use of venting/sealing arrangements effective for venting a tie bolt rotor so that, for example, an incipient leakage of a process fluid can be monitored. Additionally, in operation disclosed embodiments are effective to, for example, convey to the tie bolt a pressurized sealing fluid effective for reducing the likelihood of process fluid escaping to the atmosphere.