CONTROL SYSTEMS FOR RADIAL WINGS
The rotating rotor, under the influence of hot flue gas, is subjected to dynamic thermal distortion. To minimize the emerging gap, sealed around radial wings are used. They respond to the distortion and follow the rotor, while keeping a constant gap. With the old designs, wings seal the rotor in the hot state, and in the cold state are moved away at a safe distance.
Types of wing control systems that we use:
- two-state adjustment two-state adjustment – wings are in a “cold” or “hot” state. When the boiler reaches set up load parameters and temperature, readjustment of the wings to the "hot" state takes place; in case of boiler shutdown, it goes back to the “cold” state.
- with mechanical distortion measurement with mechanical distortion measurement– proprietary, tracking control system for the wings. There is a so called “pusher” mounted on the rotor, which changes its position along with the rotor distortion. During rotor distortion, the signal reaches the control system by means of a lever that works with the pusher, and is transmitted to the control mechanisms of the wings. The wings start “tracking” the rotor, while keeping a constant gap.
- with use of proximity sensors with use of proximity sensors – the latest, proprietary tracking control system for the wings. In this case, the continuous measurement of the rotor distortion is made by using proximity sensors mounted on the housing of the Rotary Air Preheater.