A single stage spur gear reducer is to be specified for a large industrial ventilating fan. The motor delivers 7.5 hp at a speed of 1760 rpm. The fan speed is to be about 500 rpm (± 3%). A family of economical (machined with shaping cutters) gears are available in standard pitches of 100, 80, 64, 48, 32, 24, 20, 16, 12, 10, 8, or 6 teeth per inch diameter. The bulk UTS of the manufactured steel gears is 130,000 psi and the surface hardness of the teeth is 340 BHN. Select and specify a pinion and mating gear that conform to standard limits on face width. Explicate all engineering assumptions that you make. Also be explicit as to how your final selection was made from among all of those which satisfy the design requirements.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Refrigerant 134a enters an insulated compressor operating at steady state as saturated vapor at -26°c with a volumetric flow rate of 0.18 m3/s. refrigerant exits at 9 bar, 70°c. changes in kinetic and potential energy from inlet to exit can be ignored. determine the volumetric flow rate at the exit, in m3/s, and the compressor power, in kw.

Inadequate stores control is not an obstacle to effective work order system. (clo4) a)-true b)-false