Chimney / Machine foundations/Heat transfer /Air compressor / Pumps

62問 • 1年前

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A steam generator with a economizer and air heater has an overall draft loss of 21.78 cm of water. If the stack gases are at 177°C and if the atmosphere is at 101.3 kpa and 26°C,what theoretical height of stack in meters is needed,when no draft fan are used?

D. 550

If the actual draft required for a furnace is 6.239 cm of water and the frictional losses in the stack are 15% of the theoretical draft, calculate the required stack height in meters. Assume that the flue gas have an average temperature of 149^{\circ}C and molecular weight of 30. Assume air temperature of 21°C

C. 220

A steam boiler consumes 9000 kg of coal per hour and produces 20 kg of dry flue gases per kg, air temperature is 32°C, average temperature flue gas in the chimney the chimney base coal per hour and produces 20 kg of dry flue gases is 343°C and of the flue gas entering the chimney i 260°C. The gage fluid density is 994, 78 kg per m³ and is needed when the barometric pressure is 760 mm Hg the theoretical Determine the height of the chimey?

A. 46

Machine Foundation What is the required base area of the foundation to support with specified speed of 1200 rpm amach kg? Assume bearing capacity of soil as 47.867 kpa. Use e=0.11

B. 8.87 m²

A foundation measures 3m x 4m x 5m Find the yd³ of stone needed for a concrete mixture of 1:2:4

A. 69.34

A Foundation measures 10 ft x 12 ft x 15 ft. Find the number of sacks of cement needed for 1:2:4 mixture

B. 400

A machine foundation has a trapezoidal cross-section with bases of 2 m and 3 m. The height is 1.5 m and foundation length of 4 m. Find the required yd sand to be used for 1:2:4 mixture

D. 8.63

A foundation has a weight equal to 4 times the weight of the engine. The safe bearing pressure of soil is 60 kpa and foundation has a base dimension of 2m x 4r . Find the maximum weight of the engine to be

C. 9.736 kg

A rectangular formation cross section has a blade plate dimensions of 4ft x 8ft. The uniform clearance on the height of foundation is 2.5ft. If the weight of the steel is bar reinforcements needed is 0.5% of the weight of the steel bars. Use concrete density of 2400 kg/m³

A. 51kg

A 15 cm thick wall has a thermal conductivity of 5~W/m-^{\circ}K If inside and outside surface temperature of the wall are 200^{\circ}C and 30^{\circ}C respectively. Determine the heat transmitted.

A. 5.67KW/m²

Sea water for cooling enters a condenser at 27°C and leaves at 37°C Sa condenser temperature is 45°C, what is log mean difference?

B. 12.33°C

Determine the thermal conductivity of a material that is use a 2~m^{2} test pannel, 25 mm thick with a temperature difference of 10.8^{\circ}F between the surfaces. During the 5 hours test period, the heat iransmitted is 200 KJ.

C. 0.023 W/m-°K

Birine enters a cacutting brine cooler at the rate of 60m² /hr at -10°Cand leaves at -16°C. Sp KG/KJ and specific gravity of 1.1. Determine the tons of refrigeration.

C. 33.54 TR

A heat echanger has a hot gas temperature of 300-C and suface conductance hot sode is 200 W/m-°K, an transmitted 1000 W/m², what is the surface temperature on the wall at hot side

A. 295°C

A heat exchanger is to be designed the following specifications: Hot gas temperature, 1145°C Cold gas temperature, 45°C Unit surface conductance on the hot side, 230 W/m²K Unit surface conductance on the cold side, 290 W/m²K Thermal conductivity of the metal wall, 115 W/m-°K Find the maximum thickness of metal wall between the hot gas and the cold gas, so that the maximum temperature of the wall does not exceed 545°C

C. 20 mm

An uninesulated steam pipe passes through a room in is 70 mm, and a surface temperature and emissivity are 200°C and C convection heat transfer from the surface to length of pipe? the air is 15 W/m²K 80, respectively.

A. 998 w/m²

A turbo-charged 16 cylinder, Vee-type diesel engine has an air consumption of 3000 kg/hr per cylinder to the speed.This air drawn to a filter by a centrifugal compresow air air te tempen temperature of the air from the compressor is 145°C and a counter flow air reduces the temperature of the air frotich header. Cooling enters air cooler at 30°C and leaves at 38°C C temperature difference.

A. 47°C

A turbo-charged, 16 cylinder, Vee-type diesel engine has an air consumption of 3,000 kg/hr per cylinder speed. This air is drawn in through a filter by a centrifugal compressor directly connected to the exhaus temperature of the air from the compressor is 145°C and a counter flow air cooler reduces the air temperat it goes to the engine suction header. Cooling water enters air cooler at 30°C and leaves at Calcu 38°C cooling water in m³/hr required to cool the total air requirements of the engine at rated load speed.

A. 144

An oil heater heats 100 kg per minute of oil from 35°C to 100°C in a counter flow heat exchanger. The average specific hast of the oil is 25 KJ/kg-°C. Exhaust gases used for heating enter the beater with an average specific heat of 1 KilkgCC/B mass flow rate of 250 kg/min and an initial temperature of 200°C The overall heat transfer coefficient is 75 W/m²- Determine heating surface in square meters.

D. 36

A surface condenser serving a 50,000 KW steam turbo-generator unit receives exhaust steam at the rate of 196,000 kg/ Vacuum in condenser is 702 mm Hg. Sea water for cooling enters at 29.5°C and leaves at 37.5^{\circ}C, For steam turb condenser, manufacturers consider 950 Btu/lb of steam turbine condensed as heat given up to cooling water. Calcul C. 12 logarithmic mean temperature difference in °F

C. 12

Calculate the energy transfer rate across 6° wall of firebrick with a temperature differences across thermal conductivity of the firebrick is 0.65 Btu/hr-ft-°F at the temperature interest.

B. 369 W/m²

The discharge pressure of an air compressor is 5 times the suction pressure if volume flow at suction is 0.1 m/sec what compressor 1.35 and power assuming is 98 Kpa?

B. 19.57 KW

A 10 Hp motor is use to drive an air compressor. The compressor efficiency is 75%. Determine the compressor work

B. 65 KW

The initial condition of air in an air compressor is 98 Kpa and 27°C and discharges air at 400 Kpa. The bore and stroke 355 mm and 381 mm, respectively with percent clearance of 5% running at 300 rpm. Find the volume of air at suction.

C. 620 m³/hr

An air compressor has a suction volume of 0.25 m³/sec at 97 Kpa and discharges to 650 Kpa How the compressor if there are two stages?

A. 8.27 KW

The suction condition of an air compressor is 98 Kpa, 27°C and 0.2 m³/sec If surrounding air is 100 the free air capacity in m³/sec.

B. 0.19

Carmine the percent clearance of an air compressor having 87% volumetric efficiency and compressor air pressure to be the suction ce the pressure.

D. 11%

The compressor work of an air compressor is 100 KW. If the piston speed is 15 m³/min, determine the mean effective pressure

С. 400 Кра

A double acting air compressor has 16 x 7 in, 600 rpm has what volume displacement?

D. 977 ft³/min

A wo-stage air compressor has a suction pressure of 14 psi and discharge pressure of 130 psig.What pressure in kpag

A. 209 Kpag

A two stage kg/cm² air compressor has an intercooler pressure of 3 kg/cm². What is the discharge pressure if suction kg/cm²?

B. 9 kg/cm²

The piston speed of an air compressor is 140 m/min and has a volume displacement of 0.2 m³/sec. Determ of compressor cylinder.

C. 467 mm

An air compressor piston displacement is 5000 cm³ when operates at 900 rpm and volumetric ef the mass flow of air at standard density

B. 243.5 kg/hr

A two stage compressor air at 100 kpa and 22°C discharges to 690 kpa. If intercooler intakes is 105°C, determine the value of n.

C. 1.345

Ale piston displacement of a double acting compressor running at 300 rpm is 0.4 m²/sec. If bore and stroke are unity. determine the length of stroke.

C. 371 mm

An air compressor takes air at 97 Kpa at the rate of 0.5 m³/sec and discharge 500 Kpa. If power input to the compress 120 KW, determine the heat loss in the compressor.

B. 18.55 KW

A single acting air compressor has a volumetric efficiency of 87%, operates at 500 rpm. It takes in air mean effective pressure in Kpa at discharge condition. If compressor is at mean effective pressure in kpa

D. 204

A single acting reciprocating air compressor has a clearance volume of 10%. Air is received at 90 Kg discharged at 600 Kpa. The compression and expansion are polytropic with n=1.28 The pressure dr port and 10 Kpa at the discharge port. The compressor piston displacement is 500~cm^{3} when operating the mass of compressed air in kg/hr

A. 16.76

The piston displacement double acting compressor is 0.358 m³/sec, delivers gas from 101.325 kpa and 100% to 475 kpa at the rate of 0.166 m³/sec to 150 rpm. Value of n for compression and expansion is 1.33. Find the compressor percent clearance.

A. 16.96

The piston displacement of a double acting compressor is 0.358 msc, devers gas Bom 101,305 Kpa at the rate of 0.166 m³/sec at 150 rpm. Value of n for compression and expansion is 1.33. Find there and assuming bore = stroke.

D. 450 mm

A 2-stage double acting, L-type air compressor 16" x 10" x 7", 600 rpm, has a free air unloader at each w control. It is driven through V-belts by a psi gage. Calculate piston displacement 150 Hp electric 460 V, 1,3 phase, 60 Hz, 1200 грm. Barometricpressure psi gage. Calculate the psiton displacement in in³/hr.

C. 649 m³/hr, 1661 m³/hr

A two-cylinder single-acting air compressor is directly coupled to an electric motor running at 1000 rpm follows: a. size of each cylinder =150~mm\times200~mm b. clearance volume =10\% of displacement c. exponent (n) for both compression and re-expansion process = 1.6 d. air constant = 1.4 e. air molecular mass M=29 Calculate the volume rate of air delivery in terms of standard air for a delivery pressure 8 times a ambient air conditions of 300^{\circ}K and 1 bar.

D. 5 m³/hr

A two stage compressor with first stage piston displacement of 94390 cm³/sec is driven by a motor Motor output is 35Hp. temperature suction 22°C, volumetric efficiency 14.5 psi. Find the compression efficienc Air temperature estimated is 85%. Mechanical efficiency is 95%, the intercooler pressurs 105°C and 44 Final disch is 30 psi 100 psi gage, suction

A. 77.60%

A double suction centrifugal pumps delivers 70 ft³/sec of water at a head of 12 m and running at 1250 rpm,find the specific speed of the pump?

D. 9968 rpm

The pump centerline of a centeifugal pump is located 2.5m above from the high tide level. The sea level varies two meter from high tide to low tide level. If friction loss at the suction is 0.8,determine the total suction head.

A. 5.30 meter

A centeifugal pump requires 40 ft head to diameter to deliver water from low level to higher level il pump speed is 1600 rpm, determine of the imperller diameter of the centrifugal pump.

A. 185 mm

The suction pressure of a pump reads 2 in mercury vacuum and discharge pressure reads 130 psi is use to deliver 100 gpm of water with the specific volume of 0.01639 ft³/lb. Determine the pump work.

B. 5.7 KW

A pump is to deliver 150 gpm of water at ahead of required to arrive the pump? 120 m. If pump efficiency is 70%, what is the horsepower required to drive the pump.

D. 21.33 Hp

A motor is used and motor? to drive a pump having an efficiency of 85% and 70% respectively. What is the combined effenciency of the motor.

A. 59.50%

in a boiler feed pump, the enthalpy at the entrance is 765 KJ/kg. If pump has a head of 900m, what is the the exit enthalpy of the pump

C. 774 KJ/kg

A submersible pump delivers 350 gpm of water to a height of 5 ft from the ground. The pump were installed 120 ground level and a draw down of 8 ft during the operation. If water level is 25 ft above the pump, determine the pump.

C. 7.24 KW

A boiler feed pump receives 50 li/sec of water with specific volume of 0.00112 m³/kg ahead of 750m. What is the power output of driving motor if pump efficiency is 65%?

A 505.32 KW

What power can aboiler feed pump can deliver a mass of 35 kg/s water at a head of 500 m?

D. 171.67 KW

A pump running at 100 rpm delivers water against a head of 30 m. if pump speed will increased to 120 rpm, what is the ncrease in head?

B. 13.2 m

A pump is used to deliver 50 li/sec of sea water at a speed of 120rpm. If speed will increase to 135 rpm, determine the increase in pump capacity.

D. 6.260 li/sec

A 15 KW motor running at 350 rpm is used to drive a pump. If speed will changed to 370 rpm, what is the incre power?

A. 2.72 KW

A certain pump is used to deliver 150 gpm of water having a density of 61.2 lb/ft³.The suction and discharge A certean Dum and 25 psi, respectively. The discharge gage is 2 ft above the suction gage. What is the brake power motor if pump efficiency is 75%?

A. 3.24 Hp

The discharge pipe of a pump is 400 mm height water to a tulding which mancans a pressure what power must be furnished by the pump of 100 Kpa at a in diameter delivers 0.5 m/sec of of 30 m above the reservoir If equivalent head is 2 m, what power must be furnished by the pump.

A. 211 KW

A centrifugal pump is designed for 1800 rpm and head of 61 m. Determine the speed if impeller diameter is reduced from 305 mm to 254 mm

C. 1500 rpm

Water from a reservoir A 10 m elevation is drawn by a motor driven pump to an upper reservoir B at 72 m elevation. and discharge head loss are 0.15 m, respectively. For discharge rate of 15 li/sec, find the power input to the motor efficiency is 65%.

C. 14.17 KW

The elevation of suction reservoir 5 m above the pump centerline and delivers to Kpa ft 1.5 mises of water is used to deliver 85 m elevation tank. a total head of 3m determine the power needed try by the pump.

A. 1372 kw

Water from a reservoir is pumped over a hill through a pipe 450 mm in diameter and a pressure of 1 kg/cm² at the summit. Water discharge is 30 m above the reservoir. The quantity pumped is 0.5 m³/sec. Frictional lo discharge and suction pipe and pump is equivalent to 1.5 m head loss. The speed of the pump is 800 rpm w energy must be fumished by the pump, KW

B. 206

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James Paul Concepcion · 31問 · 1年前

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