Steam Boilers, Engines, Nozzles and Turbines A single stage impulse turbine with a diameter of 1.2 m runs at 3000 r.p.m. If the blade speed ratio is 0.42, then the inlet velocity of steam will be 900 m/s 188 m/s 450 m/s 79 m/s 900 m/s 188 m/s 450 m/s 79 m/s ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines A turbine is said to have an axial discharge when the steam leaves the blade tip at _________ to the direction of the blade motion. 90° 60° 180° 270° 90° 60° 180° 270° ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines The efficiency of reaction turbine is maximum when (where α = Angle made by the absolute velocity ‘V’ at inlet) Vb = 0.5 V cosα Vb = V cos α Vb = V² cos α Vb = 0.5 V² cosα Vb = 0.5 V cosα Vb = V cos α Vb = V² cos α Vb = 0.5 V² cosα ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines A device used in a boiler to control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required, is known as Blow off cock Stop valve Fusible plug Superheater Blow off cock Stop valve Fusible plug Superheater ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines In designing air preheaters, the important design consideration is that Stack gases should not be cooled to the dew point Handling and maintenance should be easier Approach temperature should be as low as possible Heat transfer area should be optimum Stack gases should not be cooled to the dew point Handling and maintenance should be easier Approach temperature should be as low as possible Heat transfer area should be optimum ANSWER DOWNLOAD EXAMIANS APP
Steam Boilers, Engines, Nozzles and Turbines The draught (in mm of water), for maximum discharge of flue gases through the chimney, is given by (where H = Height of the chimney in meters, and T1 = Absolute temperature of air outside the chimney in K) 88.25H/T1 T1 /88.25H 176.5H/T1 T1 /176.5H 88.25H/T1 T1 /88.25H 176.5H/T1 T1 /176.5H ANSWER DOWNLOAD EXAMIANS APP
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