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Axial Compressor

The major installation work on the new axial turbo compressor group started in spring 2000, and the work was finished in November 2001. View the slide show of the construction.


Turbocompressor BBC VA 2888 was originally acquired for the Laboratory of Steam turbines at the Helsinki University of Technology in 1971; it was partially designed by Prof. Per-Holger Sahlberg. The compressor was operated together with an Esher-Wyss steam turbine.

Lapeenranta University of Technology decided to purchase the equipment to be used as a power source for a continuous, supersonic wind tunnel from the Helsinki University of Technology. LUT decided to make the hardware the goal of a project, with funding invested by the university and the Department of Energy Technology.

Disassembly and reassembly of the equipment

The hardware in Helsinki at Otaniemi consisted of an axial compressor and a steam turbine feeding into it. The steam turbine was sold back to Sulzer (now Man Turbo) and at Lappeenranta it was decided to build a high-speed motor to rotate the compressor.

The equipment was built on three stories and its disassembly took three weeks. This however proved to be the easiest step. The parts were then transferred to Lappeenranta for reassembly.

At Lappeenranta, the reassembly required a major effort because the equipment was originally designed for a completely different space.

The most important characteristics

  • Speed: 12,500 rpm
  • Pressure ratio: 3.35
  • Stage numbers: 11
  • Heat exchangers: 2
  • Oil container: 3 m3
  • Surge control equipment
  • On-line performance measurements
  • Motor: Rotatek
  • Frequency converter: Vacon

Flow measurement

A compressor can be connected to a variety of actuators (e.g. valves), whose operation, pressure loss, noise measurements, etc., can be taken. Similarly, the fatigue and vibration measurements can be taken, as well as the long-term exposure to very high flows. The measurement technology consists of a variety of sensors and calibrated measurement equipment, including measurement for supersonic speeds.

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Lower part of the compressor showing the stator vanes

The rotor in stationary position. In the background looms the white high-speed motor.

The gap between the rotating vanes and the housing is very small.