Overall heat transfer co-efficient for cooling of hydrocarbons by water

is about

(A) 50 -100 Kcal/hr.m2

.°C

(B) 50 -100 W/m2

.°K

(C) 50 -100 BTU/hr. ft.

2°F

(D) 1000 - 1500 BTU/hr. ft.

2°F

1 Answer

Answer :

(C) 50 -100 BTU/hr. ft.

2°F


Related questions

Description : The unit of heat transfer co-efficient is (A) BTU/hr. ft 2°F (B) BTU/hr. °F. ft (C) BTU/hr. °F (D) BTU/hr. ft

Last Answer : (A) BTU/hr. ft 2°F

Description : A BTU/hr.ft. 2 °F is equal to (A) 1 kcal/hr. m2°C (B) 4.88 kcal/hr. m. 2°C (C) 1 kcal/hr. m2 .°K (D) None of these

Last Answer : (B) 4.88 kcal/hr. m. 2°C

Description : Steam side heat transfer co-efficient in an evaporator is in the range of __________ kcal/hr.m2°C. (A) 10-50 (B) 100-500 (C) 1000-1500 (D) 5000-15000

Last Answer : (D) 5000-15000

Description : Pick out the correct statement. (A) 1 kcal/hr.m.°C is equal to 1 BTU/hr. ft.°F (B) In steady state heat conduction, the only property of the substance which determines the ... in the direction of temperature rise (D) In heat transfer by forced convection, Grashoff number is very important

Last Answer : (B) In steady state heat conduction, the only property of the substance which determines the temperature distribution, is the thermal conductivity

Description : Condensing film co-efficient for steam on horizontal tubes ranges from 5000 to 15000 Kcal/hr.m2 .°C. Condensation of vapor is carried out inside the tube in a shell and tube heat ... drop through the exchanger is desired (D) Temperature of the incoming vapor is very high

Last Answer : (B) Supersaturated

Description : A thin, flat & square plate measuring 2 m 2 m is freely hanging in ambient air at 25°C. It is exposed to the solar radiation falling on one side of the plate at the rate of 500 W/m2. The plate temperature will ... heat transfer co-efficient is __________ W/m2 °C. (A) 50 (B) 100 (C) 150 (D) 200

Last Answer : (B) 100

Description : 1 BTU/hr.ft.°F is equal to __________ kcal/hr. m.°C. (A) 1.49 (B) 1 (C) 4.88 (D) None of these

Last Answer : (A) 1.49

Description : What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. °K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively. (A) 2 (B) 8 (C) 10 (D) 40

Last Answer : (A) 2

Description : Pick out the wrong statement. (A) Superheated steam is preferably not used for process heating because of its low heat transfer film co-efficient (B) In a shell and tube heat exchanger ... surface heat exchangers, when the direction of fluid flow is parallel to the axis of the tube

Last Answer : (C) S.I. unit of fouling factor is Watt/m2 .°K

Description : The left face of a one dimensional slab of thickness 0.2 m is maintained at 80°C and the right face is exposed to air at 30°C. The thermal conductivity of the slab is 1.2 W/m.K and the heat transfer co-efficient from the ... temperature of the right face in °C is (A) 77.2 (B) 71.2 (C) 63.8 (D) 48.7

Last Answer : (D) 48.7

Description : The overall heat transfer co-efficient for a shell and tube heat exchangerfor clean surfaces is U0 = 400 W/m2 .K. The fouling factor after one year of operation is found to be hd0 = 2000 W/m2 .K. The overall heat transfer co￾efficient ... 1200 W/m2 .K (B) 894 W/m2 .K (C) 333 W/m2 .K (D) 287 W/m2 .K

Last Answer : (C) 333 W/m2 .K

Description : What is the unit of thermal conductivity? (A) Kcal/hr. m2 °C (B) Kcal/hr.m.°C (C) Kcal/hr.m (D) Kcal/hr. °C

Last Answer : (B) Kcal/hr.m.°C

Description : One ton of refrigeration capacity is equivalent to the heat removal rate of (A) 50 kcal/hr (B) 200 BTU/hr (C) 200 BTU/minute

Last Answer : (C) 200 BTU/minute

Description : Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole. °K (A) 0 (B) ∞ (C) 50 (D) 100

Last Answer : (B) ∞

Description : Pick out the wrong statement. (A) The condensing film co-efficient is about 3 times lower for vertical condenser as compared to the equivalent horizontal condenser for identical situation ( ... in a heat exchanger is controlled by the value of the film co-efficient, which is higher

Last Answer : (D) Overall heat transfer co-efficient in a heat exchanger is controlled by the value of the film co-efficient, which is higher

Description : . The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 and 0.1 W.m-1.°C-1 respectively. The ambient air is at 30°C ... from the outer surface in W.m-2 is (A) 165.4 (B) 167.5 (C) 172.5 (D) 175

Last Answer : (A) 165.4

Description : Three materials A, B and C of equal thickness and of thermal conductivity of 20, 40 & 60 kcal/hr. m. °C respectively are joined together. The temperature outside of A and C are 30°C and 100°C respectively. The interface ... C will be at a temperature of __________ °C. (A) 40 (B) 95 (C) 70 (D) 50

Last Answer : (C) 70

Description : Normal values of overflow rate for plain sedimentation tank using coagulants, is (A) 750 to 1000 litres/hr/m2 (B) 1000 to 1250 litres/hr/m2 (C) 1250 to 1500 litres/hr/m2 (D) 1500 litres/hr/m

Last Answer : (B) 1000 to 1250 litres/hr/m2

Description : Water filtration rate in a slow sand filter ranges from __________ litres/m2 /hr. (A) 10 to 20 (B) 100 to 200 (C) 1500 to 2500 (D) 4000 to 5000

Last Answer : (B) 100 to 200

Description : Pick out the wrong statement. (A) 'Solvates' are chemical compounds formed by solute with their solvents. When water is the solvent, then it is called a 'hydrate' (B) In heat exchanger ... vertical evaporators, area of central downtake is about 50 to 100% of the total tube cross-sectional area

Last Answer : (C) Heat transfer co-efficient during nucleate boiling is not influenced by the agitation imparted

Description : The heat flux (from outside to inside) across an insulating wall with thermal conductivity, K = 0.04 W/m.°K and thickness 0.16m is 10 W/m2 . The temperature of the inside wall is - 5°C. The outside wall temperature is (A) 25°C (B) 30°C (C) 35°C (D) 40°C

Last Answer : (C) 35°C

Description : One ton of refrigeration is not equivalent to the heat removal rate of (A) 200 BTU/minute (B) 50 kcal/minute (C) 50 kJ/sec (D) 3.5 KW

Last Answer : (C) 50 kJ/sec

Description : Heat load in a cooling tower (A) Means the amount of heat thrown away (KCal/hr.) by the cooling tower (B) Is equal to the number of kg, of water circulated times the cooling range (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Description : Optimum reaction temperature in steam reforming of naphtha is __________ °C. (A) 700 - 1000 (B) 300 - 450 (C) 1500-1700 (D) 100-200

Last Answer : (A) 700 - 1000

Description : Pick out the wrong statement: (A) With change in temperature, the radiant energy emitted by a black body remains unchanged (B) Absorptivity of a body approaches unity in case of diffuse reflection (C) Absorptivity of ... unity (D) Value of Stefan-Boltzmann constant is 4.876 10 -8 KCal/m2 .hr.°K4

Last Answer : (A) With change in temperature, the radiant energy emitted by a black body remains unchanged

Description : Which of the following has the lowest overall heat transfer co-efficient? (A) Dowtherm (B) Molten sodium (C) Water (D) Air

Last Answer : (D) Air

Description : Double pipe heat exchangers are preferably useful, when (A) High viscosity liquid is to be cooled (B) Requirement of heat transfer area is low (C) Overall heat transfer co-efficient is very high (D) A corrosive liquid is to be heated

Last Answer : (B) Requirement of heat transfer area is low

Description : In case of vertical tube evaporator, with increase in liquor level, the overall heat transfer co-efficient (A) Increases (B) Decreases (C) Is not affected (D) May increase or decrease; depends on the feed

Last Answer : (B) Decreases

Description : If h1 = inner film co-efficient and /h2 = outer film co-efficient, then the overall heat transfer co-efficient is (A) Always less than h1 (B) Always between h1 and h2 (C) Always higher than h2 (D) Dependent on metal resistance

Last Answer : (B) Always between h1 and h2

Description : Overall heat transfer co-efficient of a particular tube is U1 . If the same tube with some dirt deposited on either side has coefficient U2 , then (A) U1 = U2 (B) U2 > U1 (C) U1 > U2 (D) U1 = dirt factor - U2

Last Answer : (A) U1 = U2

Description : Out of the following four assumptions used in the derivation of theequation for LMTD [LMTD = (∆t1 - ∆t2 )/ln(∆t1 /∆t2 )], which one is subject to the largest deviation in practice ? (A) Constant ... (B) Constant rate of fluid flow (C) Constant specific heat (D) No partial phase change in the system

Last Answer : (B) Constant rate of fluid flow

Description : Steam is to be condensed in a shell and tube heat exchanger, 5 m long with a shell diameter of 1 m. Cooling water is to be used for removing the heat. Heat transfer co-efficient ... ) Horizontal heat exchanger with steam on tube side (D) Horizontal heat exchanger with steam on shell side

Last Answer : (B) Vertical heat exchanger with steam on shell side

Description : The unit of conductance in SI unit is (A) W/m (B) W/m2 (C) W/°K (D) W/m°K

Last Answer : (C) W/°K

Description : In a heat exchanger, one transfer unit means (A) A section of the exchanger in which change in temperature of one stream equals the average driving force in the section (B) The size of the exchanger in which heat transfer rate is 1 kcal/hr (C) Both (A) and (B) (D) None of these

Last Answer : (A) A section of the exchanger in which change in temperature of one stream equals the average driving force in the section

Description : Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re 0.8 . Pr n , is not valid, if the value of (A) n = 0.4 is used for heating (B) n = 0.3 is used for cooling (C) Reynolds number for the flow involved is > 10000 (D) Reynolds number for the flow involved is < 2100

Last Answer : (D) Reynolds number for the flow involved is < 2100

Description : I am wondering if Frigidaire FAX054P7A 5000 BTU Window Air Conditioner will be sufficient for my 15 Ft by 10 Ft (total bedroom area 150 square feet) bedroom as far as adequate cooling is concerned?

Last Answer : The Frigidaire FAX054P7A is designed to cool a room up to 150 square feet, so your bedroom size is just at the limit of it's capacity. Assuming you aren't someone who gets exceptionally hot, this unit should work fine.

Description : Normal values of overflow rate for plain sedimentation tanks in litres/hr/m2 , generally range  between  (A) 100 to 250  (B) 250 to 500  (C) 500 to 750  (D) 750 to 1000 

Last Answer : (C) 500 to 750 

Description : The value of gas constant 'R' is (A) 1.987 cal/gm mole °K (B) 1.987 BTU/lb. mole °R (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Description : Hydrogen content in petroleum products varies from 12 to 15% (by weight). As a result the difference between gross and net heating value of petroleum fuels varies in the range of __________ kcal/kg. (A) 600-750 (B) 250-350 (C) 1000-1500 (D) 2000-2500

Last Answer : (A) 600-750

Description : Gasification of the solid fuel converts its organic part into combustible by interaction with air/oxygen and steam so as to obtain a secondary gaseous fuel of high calorific value having no ash. Gasification reactions are ... __________ °C. (A) 400-500 (B) 900-1000 (C) 1400-1500 (D) 1700-1800

Last Answer : (B) 900-1000

Description : A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2 .K. The Biot number is (A) 5.6 (B) 0.025 (C) 3.5 (D) 0.0035

Last Answer : (B) 0.025

Description : The amount of heat required to raise the temperature of 1kg of water through 1 °C is called ______.  A. Calorie  B. Joule  C. BTU  D. Kilocalorie

Last Answer : Kilocalorie

Description : Coating thickness in case of galvanising of steel sheet generally corresponds to the deposition of __________ gms of zinc per m2 of steel strip. (A) 5-10 (B) 1000-1500 (C) 120-500 (D) 1500-3000

Last Answer : Option C

Description : The wetted wall tower is used to determine (A) Individual mass transfer co-efficient (M.T.C.) in gaseous system (B) M.T.C. of individual components in a liquid-liquid system (C) M.T.C. of liquid in liquid-gas system (D) The overall M.T.C. of the system

Last Answer : (A) Individual mass transfer co-efficient (M.T.C.) in gaseous system

Description : The overall mass transfer co-efficient for the absorption of SO2 in air with dilute NaOH solution can be increased substantially by (A) Increasing the gas film co-efficient (B) Increasing the liquid film co-efficient (C) Increasing the total pressure (D) Decreasing the total pressure

Last Answer : (A) Increasing the gas film co-efficient

Description : In a vapor-liquid contacting equipment, the overall gas phase mass transfer co-efficient (M.T.C), KG is related to individual co-efficients (KG and KL ) as (A) KG = 1/KG + m/KL (B) 1/KG = 1/KG + m/KL (C) 1/KG = 1/KL + m/KG (D) KG = 1/KL + m/KG

Last Answer : (B) 1/KG = 1/KG + m/KL