Experimental Study on the Wear-in Behaviour of Brush Seals

Although some investigations on the wear behaviour of brush seals can be found in the literature, not all aspects are yet understood during the wear-in process of the seal in operation. However, it is important to understand all aspects in order to en- sure a long service life of the seal. The present paper gives an overview of the procedure, the results and the knowledge gained through the long-term rub tests carried out with a tungsten car- bide coated rotor with the aim of determining the time required to wear the seal in (”time-on-condition”). The total test duration of the cyclic tests was approx. 100 h. The measurements have shown that on the basis of the applied test procedure the initial wear-in phase is completed after approx. 40 cumulated operat- ing hours and only very little wear occurs afterwards. Further- more, it could be shown that the major part of the wear occurred within a short period of time within these 40 h and that the prop- erties of the test cycle have a great influence on the wear-in time. The coupling of the rubbing intensity with time is achieved by measuring the transient rotor temperatures during rubbing. ... mehrThe tests carried out have also shown that the influence of the concentricity properties of the rotor can resulting in rotor temperature deviations over the circumference (”hot spots”).