The diameter of the pulley on the compressor shaft must not be greater than 1.2 metre while the centre distance between the pulleys is limited to 1.85 metre. A compressor, requiring 95000W is to run at about 500 r.p.m. The drive is by V- belts from an electric motor running at 1500 r.p.m. The belt speed should not exceed 1500 m/min. The coefficient of friction between the belt and the pulley is 0.3. Determine the number of V-belts required to transmit the power if each belt has a crosssectional area of 3 cm2, density 1100 kg/m3 and an allowable tensile stress of 3 MPa. The groove angle of the pulley is 50°. Calculate also the length required of each belt.

The diameter of the pulley on the compressor shaft must not be greater than 1.2 metre while the centre distance between the pulleys is limited to 1.85 metre. A compressor, requiring 95000W is to run at about 500 r.p.m. The drive is by V- belts from an electric motor running at 1500 r.p.m. The belt speed should not exceed 1500 m/min. The coefficient of friction between the belt and the pulley is 0.3. Determine the number of V-belts required to transmit the power if each belt has a crosssectional area of 3 cm2, density 1100 kg/m3 and an allowable tensile stress of 3 MPa. The groove angle of the pulley is 50°. Calculate also the length required of each belt.

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter23: Compressors

Section: Chapter Questions

Problem 9RQ: Describe the reciprocating compressor piston, rod, crank-shaft, valves, valve plate, head, shaft...

See similar textbooks

Similar questions

Q1: A connecting rod for an I.C. engine running at 1800 r.p.m. and developing a maximum pressure of 3.15 MPa. The diameter of the piston is 100 mm ; mass of the reciprocating parts per cylinder 2.25 kg; length of connecting rod 380 mm; stroke of piston 190 mm and compression ratio 6:1. Take a factor of safety of 6 for the design. Take length to diameter ratio for big end bearing as 1.3 and small end bearing as 2 and the corresponding bearing pressures as 10 MPa and 15 MPa. The density of material of the rod may be taken as 8000 kg/m³ and the allowable stress in the bolts as 60 MPa and in cap as 80 MPa. The rod is to be of I-section for which you can choose your own proportions. Calculate the dimension of I- section of the connecting rod. Ixx = 4 lyy A = 11t? Ixx %3D kxx %3D A Fc = FL = p Apiston A oc H = 51 X-- -X 31 Buckling load WB = 2 1+ a xX. Y
An I.C. engine with brake power output an AF ratio of 15 to 1 uses a fuel with a heating value of 20,000 Btu/lb. fuel. The unit produces a continuous brake power output of 500 bhp while consuming 90 lb. of fuel during a 30-minute period of operation. From the engine performance, the indicated thermal efficiency is found to be 39 percent. Calculate (a) the mechanical efficiency, %; (b) the required air flow, lb. air/min; and (c) the brake specific fuel consumption, lb. fuel/bhp-hr.
The Stroke of a gas engine which works on the constant volume cycle is 310 mm. The pressure at the beginning of the compression is 1.42 bar and at the end of compression is 13.18 bar. Assuming compression follows the law PV^1.36 = C, Calculate the clearance between the piston and cylinder cover at the end of compression in mm of length.
Q1/Explain briefly the effects of heat loss factor on actual cycles reinforcing your answer with drawing
Problems-2 1- single cylinder single acting compressor has pressure and temperature at the section line of (100kPa) and (300K) respectively. The pressure at the end of the compression stroke is (800kPa). The volume of the stroke is (500cm') and volume of clearance is (20cm'). The compression is according to PV25 C. Determine (1) volumetric efficiency, (2) the work done per kg of air (3) the power consumption, (4) isothermal efficiency.
John’s automobile has a three-liter SI-V6 engine that operates on a four-stroke cycle at 3600 RPM. The compression ratio is 9.5, the length of connecting rods is 16.6 cm, and the engine is square (B=S). at this speed, combustion ends at 20o at T.D.C. This engine is connected to Dynamometer which gives a brake output torque reading of 205 N-m. At his speed, air enters the cylinders at 85 kPa and 60o C, and the mechanical efficiency of the engine is 85%. Calculate: (a) Brake power, HP || (b) Indicated Power, HP || (c) Brake Mean Effective Pressure, Bmep , Psia || (d) Indicated Mean Effective Pressure, Imep, Psia || (e) Friction Mean Effective Pressure, Fmep, Psia
A multi-cylinder engine is to run at a speed of 600 r.p.m. On drawing the crank-effort diagram to scale of 1 cm = 2452.5 N-m and 1 cm = 30°, the areas above and below the mean torque line in sq.cm. are as follows: +1.6, –1.72, +1.68, –1.91, +1.97 and -1.62. The speed is to be kept within ±1% of the mean speed of the engine. Calculate the necessary moment of inertia of the flywheel. Determine the suitable dimensions of a rectangular flywheel rim, if the breadth is twice the thickness. The density of the cost- iron is 725 gm/cm³ and its hoop stress is 588.6 N/cm?. Assume that the rim contributes 92% of the flywheel effect. %3D
5. A 5.6 liter V10 compression-ignition truck engine operates on a four stroke cycle at 3600 rpm producing 162 kW of power in the shaft. The bore and stroke of the engine are related as S = 1.12 B. Calculate: (15 pts) a. Average piston speed (m/s) b. Torque (N-m) c. Brake mean effective pressure
ACTIVITY 8 A tractor has a 300-hp engine under standard condition. What is the power engine when it is operating at an altitude of 5650 ft and at a temperature of 85 deg. The efficiency factor will be a 55 min hour.
An engine of 250 mm bore and 375 mm stroke work on otto cycle. The clearance volume (V2) is 0.00263 m3. The initial pressure and temperature are 1 bar and 50 C, if the maximum pressure (P3) is 25 bar, the network in the cycle in KJ/Kg will be: *
Q2 An automotive engine has a bore of 90 mm; the stroke is 110 mm; and the length of the connecting rod is 166 mm Knowing that the volume of the combustion chamber is 75 cm³ and the intake valve closes 18° crank angle degree after BDC. If injection Started 10 degrees before TDC and ends 40 degree after TDC. And the engine is running at 3000 rpm. a. Calculate the geometrical compression ratio and the actual compression ratio? b. Find the ratio between the maximum speed of the piston to the mean piston speed for this engine? c. Find the injection period
Problems-2 1- single cylinder single acting compressor has pressure and temperature at the section line of (100kPa) and (300K) respectively. The pressure at the end of the compression stroke is (800kPa). The volume of the stroke is (500cm') and volume of clearance is (20cm'). The compression is according to PV25=C. Determine (1) volumetric efficiency, (2) the work done per kg of air (3) the power consumption, (4) isothermal efficiency. 2- atmospheric air at (100kPa) and (27°C) is compressed adiabatically in ideal reciprocating compressor with single cylinder and single acting to a pressure of (450kPa). The clearance volume is (5%) of the compression stroke. The compressor 70 compress (0.1kg) of air per cycle. Find the volumetric efficiency and the work done on the compressor and the isothermal efficiency. 3- Air compressor is required to deal with atmospheric air at (105kPa) and (300K). the temperature pressure of air at the end of the section line are (20°C) and (100kPa) respectively.…