Blade Tip Clearance
Introduction
Blade Tip Clearance Solutions for Turbines, Fans, and Rotating Machinery
When it comes to turbines and fans, blade tip clearance — the distance between the tip of the blade and the surrounding case — is one of the most crucial measurements. If the blade tips are too close, thermal expansion or vibration could cause destructive contact. If they’re too far, turbine efficiency and performance suffer. That’s why accurately measuring turbine blade tip clearance, fan blade tip clearance, or any form of tip clearance is essential for safe, reliable operation.
The Inquiry: Measuring Turbine Tip Clearance Through Inspection Ports
A global power equipment manufacturer needed a way to measure turbine tip clearance inside a steam turbine — without disassembling the machine. The challenge: measure the clearance between uniquely shaped turbine blade tips and the casing, using capacitive sensors that could fit precisely into threaded inspection ports. MTI Instruments was called upon to deliver a customized solution that worked flawlessly within these constraints.
The Solution: MTI’s Digital Accumeasure™ for Blade and Tip Clearance
MTI’s Digital Accumeasure™ system offers high-accuracy measurement of blade clearance and tip clearance using miniature capacitive probes. These advanced sensors are digitally corrected for linearity, allowing precise measurement even at larger-than-usual working gaps — a challenge for traditional analog capacitive systems.
To meet the client’s needs, MTI:
- Designed ultra-small probes to match the turbine’s port threading.
- Optimized the system to detect specialized blade tip shapes.
- Ensured no risk of contact with narrow blade tips, even in confined spaces.
Integration and Performance
The system was validated at MTI Instruments’ lab, ensuring the blade tip clearance sensors would work reliably without interference or impact. Using a MODBUS output, the system seamlessly transmitted real-time tip clearance data to maintenance engineers’ smartphones, enabling fast and informed decision-making during turbine rebuilds.
Field Results: Fan and Turbine Blade Tip Clearance Measurement
Two pilot systems are in successful field operation. During slow-speed rebuild inspections, the sensors confirm that blade tips will not rub during high-speed operation — minimizing the risk of costly damage.
Custom Tip Clearance Solutions for Every Application
Whether you’re dealing with a fan blade tip, a high-speed turbine blade, or a unique rotating component, MTI can customize a tip clearance measurement system to match your specs. Our capacitive sensing technology ensures you get accurate results — without breaking your budget.
Need a custom blade tip clearance solution?
Contact MTI Instruments today. Our application engineers are ready to help ensure your system runs efficiently, safely, and precisely.
