Standard Technical Features of BTG System for Supercritical 660 ...

Standard Technical Features of BTG System for Supercritical 660/800 MW Thermal Unitsc) Fan rotational 1500 rpm (max.) 750 rpm (max.)speedd) Air/ flue gas flow blade pitch control blade pitch controlcontrole) Fan critical speed not less than 125% offan maximumoperating speed speedf) Fan componentdesign*g) Fan casingmaterial &thicknessh) Fan Housingdesign pressureto withstand torsionalstresses three (3)times the normal/ fullload motor torque atall speedsCarbon steel, 6.00mm (min.)Shut off head of fan56not less than 125% offan maximum operatingto withstand torsionalstresses three (3) timesthe normal/ full loadmotor torque at allspeedsAbrasion and wearresistant, high BHNsteel having minimum8.0 mm thickness or8mm mild steel withliner of thickness 10mm(min.)Shut off head of fan* The ID fan components such as blades, hubs, casing etc. shall be chosento encounter the high dust burden of the order of 250 mg/Nm 3 . Theminimum wear life of ID fan components shall not be less than 25000hours of operation from the date of commissioning.ii) Silencers shall be provided at the suction of FD fans to limit the noiselevel as specified. FD fan suction shall be provided with rigid bird andtrash screen assembly and shall have suitable arrangement to avoidrainwater from directly entering the fan.iii) Fan Bearingsa) Bearing shall be provided with oil bath to prevent damage in case ofcomplete loss of plant auxiliary power when the fans must coastdown without power.b) Oil reservoir in bearings housing shall be sized for maintaininglubrication for extended periods in case of oil circulation system isout of service.c) Duplex Pt-RTDs (100 ohm at 0 0 C) and temperature indicators shallbe provided for each bearing as per standard practice of the OEM forlocal as well as remote monitoring of bearing metal temperature.d) For mounting of vibration pads/ pickups, flat surfaces shall beprovided both in X and Y directions, on the bearing housing.