|
Vol.17, No.3, 2017, pp.221–228 |
|
WEAR RESISTANCE IMPROVEMENT OF THERMAL PLANT FAN MILL IMPACT PLATES BASED ON NUMERICAL FLOW SIMULATION Mirko Kozić1, Slavica Ristić2, Boris Katavic3, Bore Jegdić4, Mirjana Prvulović3, Milan Prokolab3, Suzana Linić5 1)VTI (Military Technical Institute), Belgrade, Serbia mkozic@open.telekom.rs 2)Central Institute for Conservation, Belgrade, Serbia 3)Institute Goša, Belgrade, Serbia 4)ICTM – Inst. of Chemistry, Technology & Metallurgy, Belgrade, Serbia 5)University of Belgrade, Innovation Centre of the Faculty of Mech. Engng., Belgrade, Serbia |
|
Abstract Numerical simulation of 3D multiphase flow is performed to determine the velocity field in the fan mill. The mixture model of the Euler-Euler approach is used. Recirculating gas is a primary phase that carries granular phases including the coal powder and sand. The latter causes heavy wear of mill impact plates. The optimal form of hardfacing geometry and technology has an impact both on velocity magnitude and direction of flow in such a way as to reduce plate wear. This paper presents results of surface modification (based on numerical simulation), implemented on impact plates of the fan mill in the Kostolac B power plant in Serbia. Fishbone hardfacing is made in order to increase the lifetime of impact plates and extend the period between overhauls of fan mills. The experimental tests of fishbone surfacing plates, in exploitation conditions, show that the applied modification, hardfacing technologies and coating materials, give expected results. The application of this hardfacing in the form of a fishbone is simpler, faster and more economical compared to complete overlaying and honeycomb impact plate surfacing. The relative weight loss of base plate after an 1440-hour period of exploitation is 8%, while the weight losses for the hardfaced plate is below 7%. Keywords: thermal power plant, wear, fan mill, multiphase flow, CFD |
|
full article (5723 KB)
|
