Which of the following parameters is not responsible for the heat loss from a hot steam carrying bare pipe surface located in a room without fans? (A) Emissivity of pipe surface (B) Diameter & length of the pipe (C) Temperature of hot pipe surface & that of air in the room (D) None of thes

Which of the following parameters is not responsible for the heat loss
from a hot steam carrying bare pipe surface located in a room without fans?
(A) Emissivity of pipe surface
(B) Diameter & length of the pipe
(C) Temperature of hot pipe surface & that of air in the room
(D) None of thes
by

1 Answer

Answer :

Option D
by

Related questions

Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at 35°C (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C (C) Boiling brine kept in open vessel when the bottom surface temperature of the vessel is maintained constant at 180°C (D) A sub-cooled refrigerant liquid at 8°C flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C

Description : Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at ... flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C

Last Answer : (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C

Calculate the rate of heat transfer by radiation from an unlagged steam pipe, 50 mm o.d. at 393K to air at 293K emissivity e = 0.9.

Description : Calculate the rate of heat transfer by radiation from an unlagged steam pipe, 50 mm o.d. at 393K to air at 293K emissivity e = 0.9.

Last Answer : Rate of heat transfer by radiation Assume length of pipe = 1 m

For a given ambient air temperature with increase in the thickness of insulation of a hot cylindrical pipe, the rate of heat loss from the surface would (A) Decrease(B) Increase(C) First decrease and then increase(D) First increase and then decrease

Description : For a given ambient air temperature with increase in the thickness of insulation of a hot cylindrical pipe, the rate of heat loss from the surface would (A) Decrease (B) Increase (C) First decrease and then increase (D) First increase and then decrease

Last Answer : (D) First increase and then decrease

Loss of heat from untagged steam pipe to the ambient air is by (A) Conduction (B) Convection (C) Radiation (D) All (A), (B) & (C)

Description : Loss of heat from untagged steam pipe to the ambient air is by (A) Conduction (B) Convection (C) Radiation (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

In a hot water heating system, there is cylindrical pipe of length 28 m and diameter 5 cm. Find the total radiating surface in the system. -Maths 9th

Description : In a hot water heating system, there is cylindrical pipe of length 28 m and diameter 5 cm. Find the total radiating surface in the system. -Maths 9th

Last Answer : Height of cylindrical pipe = Length of cylindrical pipe = 28m Radius of circular end of pipe = diameter/ 2 = 5/2 cm = 2.5cm = 0.025m Now, CSA of cylindrical pipe = 2πrh, where r = radius and h = height of ... = 2 (22/7) 0.025 28 m2 = 4.4m2 The area of the radiating surface of the system is 4.4m2.

reduction in thermal resistance during heat transfer does not occur in the (A) Convection heat transfer by stirring the fluid and cleaning the heating surface (B) Conduction heat transfer by reduction in the material thickness and increase in the thermal conductivity (C) Radiation heat transfer by increasing the temperature and reducing the emissivity (D) None of these

Description : reduction in thermal resistance during heat transfer does not occur in the (A) Convection heat transfer by stirring the fluid and cleaning the heating surface (B) Conduction heat transfer by ... Radiation heat transfer by increasing the temperature and reducing the emissivity (D) None of these

Last Answer : Option C

Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan (A) With greater number of blades (B) Of increased diameter (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan (A) With greater ... (B) Of increased diameter (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Disc compensators are provided in large diameter fuel gas carrying pipelines to (A) Keep the pipe in proper orientation (B) Make the pipe joint leak-proof (C) Account for contraction/expansion of pipe due to temperature changes of the surroundings (D) Account for the pressure variation side the pipeline

Description : Disc compensators are provided in large diameter fuel gas carrying pipelines to (A) Keep the pipe in proper orientation (B) Make the pipe joint leak-proof (C) Account for contraction/expansion ... due to temperature changes of the surroundings (D) Account for the pressure variation side the pipeline

Last Answer : (C) Account for contraction/expansion of pipe due to temperature changes of the surroundings

The heating capacity of muffle furnace depends on the (A) Surface area & emissivity of the stock (B) Properties of the muffle wall (temperature, area, and emissivity) (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The heating capacity of muffle furnace depends on the (A) Surface area & emissivity of the stock (B) Properties of the muffle wall (temperature, area, and emissivity) (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Pick out the wrong statement. (A) Economy of a multiple effect evaporator is not influenced by the boiling point elevation (B) Two identical cubes of iron and copper will have the same heat content under the same conditions of temperature (C) Double pipe heat exchangers are mostly used in the field of refrigeration (D) Finned tube heat exchangers are suitable for heating air by steam

Description : Pick out the wrong statement. (A) Economy of a multiple effect evaporator is not influenced by the boiling point elevation (B) Two identical cubes of iron and copper will have the same heat ... in the field of refrigeration (D) Finned tube heat exchangers are suitable for heating air by steam

Last Answer : (B) Two identical cubes of iron and copper will have the same heat content under the same conditions of temperature

TIG welding, thoriated tungsten electrodes are used, because it (A) Has higher current carrying capacity (B) Has better electron emissivity (C) Is stronger than ordinary tungsten (D) Is easy to prepare

Description : TIG welding, thoriated tungsten electrodes are used, because it (A) Has higher current carrying capacity (B) Has better electron emissivity (C) Is stronger than ordinary tungsten (D) Is easy to prepare

Last Answer : Option B

The heat transfer by radiation from a mild steel surface is to be reduced by reducing the emissivity of the surface. This can be best achieved by (A) Painting the surface black (B) Painting the surface white (with aluminium paint) (C) Giving the surface a mirror finish (D) Roughening the surface

Description : The heat transfer by radiation from a mild steel surface is to be reduced by reducing the emissivity of the surface. This can be best achieved by (A) Painting the surface black (B) ... white (with aluminium paint) (C) Giving the surface a mirror finish (D) Roughening the surface

Last Answer : (B) Painting the surface white (with aluminium paint)

Identification of pipelines carrying different liquids and gases is done by the __________ of the pipe(A) Diameter(B) Colour(C) Altitude(D) None of these.

Description : Identification of pipelines carrying different liquids and gases is done by the __________ of the pipe. (A) Diameter (B) Colour (C) Altitude (D) None of these

Last Answer : (B) Colour

Pick out the wrong statement. (A) The controlling resistance in case of heating of air by condensing steam is in the air film (B) The log mean temperature difference (LMTD) for counter flow and parallel flow can be theoretically same when any one of the fluids (hot or cold fluid) passes through the heat exchanger at constant temperature (C) In case of a 1 - 2 shell and tube heat exchanger, the LMTD correction factor value increases sharply, when a temperature cross occurs (D) Phase change in case of a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature

Description : Pick out the wrong statement. (A) The controlling resistance in case of heating of air by condensing steam is in the air film (B) The log mean temperature difference (LMTD) for ... a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature

Last Answer : (C) In case of a 1 - 2 shell and tube heat exchanger, the LMTD correction factor value increases sharply, when a temperature cross occurs

A __________ surface has the maximum thermal emissivity out of the following. (A) Black & smooth (B) Black & rough (C) White & smooth (D) White & rough

Description : A __________ surface has the maximum thermal emissivity out of the following. (A) Black & smooth (B) Black & rough (C) White & smooth (D) White & rough

Last Answer : (B) Black & rough

In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the (A) Rate of firing and emissivity of flame (B) Thermal conductivity of the charge & structural materials of furnace (C) Nature of process; whether batch, continuous or intermittent (D) All (A), (B) and (C)

Description : In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the (A) Rate of firing and emissivity of flame (B) Thermal conductivity of the charge & ... (C) Nature of process; whether batch, continuous or intermittent (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

The thermal radiative flux from a surface of emissivity = 0.4 is 22.68 kW/m2 . The approximate surface temperature (K) is (Stefan-Boltzmann constant = 5.67 × 10 -8 W/m2 .K4 )(A) 1000(B) 727(C) 800(D) 1200

Description : The thermal radiative flux from a surface of emissivity = 0.4 is 22.68 kW/m2 . The approximate surface temperature (K) is (Stefan-Boltzmann constant = 5.67 × 10 -8 W/m2 .K4 ) (A) 1000 (B) 727 (C) 800 (D) 1200

Last Answer : (A) 1000

Pick out the wrong statement. (A) The emissivity of a surface decreases, if it gets corroded by atmospheric environment (B) The emissivity of a surface increases with increase in surface roughness (C) The emissivity of a polished surface is quite low (D) The emissivity of a non-metallic surface decreases with increase in the temperature

Description : Pick out the wrong statement. (A) The emissivity of a surface decreases, if it gets corroded by atmospheric environment (B) The emissivity of a surface increases with increase in surface roughness ... quite low (D) The emissivity of a non-metallic surface decreases with increase in the temperature

Last Answer : (A) The emissivity of a surface decreases, if it gets corroded by atmospheric environment

The heating capacity of continuous reheating furnace depends upon the (A) Hearth area and furnace temperature (B) Emissivity of the stock (C) Ratio of wall surface to stock surface (D) All (A), (B) and (C)

Description : The heating capacity of continuous reheating furnace depends upon the (A) Hearth area and furnace temperature (B) Emissivity of the stock (C) Ratio of wall surface to stock surface (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Air is best heated with steam in a heat exchanger of (A) Plate type (B) Double pipe type with fin on steam side (C) Double pipe type with fin on air side (D) Shell and tube type

Description : Air is best heated with steam in a heat exchanger of (A) Plate type (B) Double pipe type with fin on steam side (C) Double pipe type with fin on air side (D) Shell and tube type

Last Answer : (C) Double pipe type with fin on air side

Heat transfer rate to the charge/stock in a furnace does not depend upon the (A) Type of fuels viz. solid, liquid or gaseous (B) Flue gas temperature (C) Emissivity of refractory walls (D) Initial temperature of the charged stock

Description : Heat transfer rate to the charge/stock in a furnace does not depend upon the (A) Type of fuels viz. solid, liquid or gaseous (B) Flue gas temperature (C) Emissivity of refractory walls (D) Initial temperature of the charged stock

Last Answer : (A) Type of fuels viz. solid, liquid or gaseous

A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place (A) The better insulation material should be put just next to pipe (i.e., inside) (B) The better insulating material should be put outside (C) Either of the insulating material could be put on either side (D) Steam temperature is considered before deciding as to which insulating material is to be put inside (i.e., just next to the pipe)

Description : A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place (A) The better insulation material should be put just ... to which insulating material is to be put inside (i.e., just next to the pipe)

Last Answer : (A) The better insulation material should be put just next to pipe (i.e., inside)

LMTD for evaporators & condensers for a given terminal parameters & set of conditions for counter-flow is equal to that for parallel flow. In such heat exchangers, with one of the fluids condensing or evaporating, the surface area required is the least in the __________ flow. (A) Parallel (B) Mixed (C) Counter flow (D) Same in either 'a', b' or 'c'

Description : LMTD for evaporators & condensers for a given terminal parameters & set of conditions for counter-flow is equal to that for parallel flow. In such heat exchangers, with one of the fluids condensing or evaporating, the surface ... Parallel (B) Mixed (C) Counter flow (D) Same in either 'a', b' or 'c'

Last Answer : (D) Same in either 'a', b' or 'c'

Presence of sodium tripolyphosphate (an additive) in synthetic detergent (A) Facilitates its use even in hard water (by sequestering the water￾hardening Ca & Mg ions) (B) Inhibits its corrosive effects (C) Does not allow redeposition of dirt on the cleaned surface (D) None of thes

Description : Presence of sodium tripolyphosphate (an additive) in synthetic detergent (A) Facilitates its use even in hard water (by sequestering the water￾hardening Ca & Mg ions) (B) Inhibits its corrosive effects (C) Does not allow redeposition of dirt on the cleaned surface (D) None of thes

Last Answer : (A) Facilitates its use even in hard water (by sequestering the water￾hardening Ca & Mg ions)

Which of the following two quantities when same, makes one pipe system equivalent to another pipe system? (A) Head & discharge(B) Length & discharge(C) Length & diameter(D) Friction factor & diameter

Description : Which of the following two quantities when same, makes one pipe system equivalent to another pipe system? (A) Head & discharge (B) Length & discharge (C) Length & diameter (D) Friction factor & diameter

Last Answer : (A) Head & discharge

The discharge co-efficient for an orifice meter does not depend upon the (A) Pipe length (B) Ratio of pipe diameter to orifice diameter (C) Type of orifice & the Reynolds number (D) Pipe diameter

Description : The discharge co-efficient for an orifice meter does not depend upon the (A) Pipe length (B) Ratio of pipe diameter to orifice diameter (C) Type of orifice & the Reynolds number (D) Pipe diameter

Last Answer : (A) Pipe length

For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) (A) μ (B) 1/μ (C) √μ (D) 1/√μ

Description : For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) (A) μ (B) 1/μ (C) √μ (D) 1/√μ

Last Answer : (B) 1/μ

Consider two pipes of same length and diameter through which water is passed at the same velocity. The friction factor for rough pipe is f1 and that for smooth pipe is f2 . Pick out the correct statement(A) f1 = f2 (B) f1 < f2 (C) f1 > f2 (D) Data not sufficient to relate f1 & f2

Description : Consider two pipes of same length and diameter through which water is passed at the same velocity. The friction factor for rough pipe is f1 and that for smooth pipe is f2 . Pick out the correct statement. (A) f1 = f2 (B) f1 < f2 (C) f1 > f2 (D) Data not sufficient to relate f1 & f2

Last Answer : (C) f1 > f2

The pressure drop per unit length for laminar flow of fluid through a long pipe is proportional to (where, A = cross-sectional area of the pipe & D = Diameter of the pipe) (A) A (B) D (C) 1/A (D) 1/A2

Description : The pressure drop per unit length for laminar flow of fluid through a long pipe is proportional to (where, A = cross-sectional area of the pipe & D = Diameter of the pipe) (A) A (B) D (C) 1/A (D) 1/A2

Last Answer : (C) 1/A

A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if (A) Length of both the pipes is same (B) Diameter of both the pipes is same (C) Loss of head and discharge of both the pipes is same (D) Loss of head and velocity of flow in both the pipes is same

Description : A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if (A) Length of both the pipes is same (B) Diameter of both the pipes is same (C) Loss of ... discharge of both the pipes is same (D) Loss of head and velocity of flow in both the pipes is same

Last Answer : Answer: Option C

Two pipe systems can be said to be equivalent, when the following quantities are same (A) Friction loss and flow (B) Length and diameter (C) Flow and length (D) Friction factor and diameter

Description : Two pipe systems can be said to be equivalent, when the following quantities are same (A) Friction loss and flow (B) Length and diameter (C) Flow and length (D) Friction factor and diameter

Last Answer : Answer: Option A

According to Darcy's formula, the loss of head due to friction in the pipe is (where f = Darcy's coefficient, l = Length of pipe, v = Velocity of liquid in pipe, and d = Diameter of pipe) (A) flv²/2gd (B) flv²/gd (C) 3flv²/2gd (D) 4flv²/2gd

Description : According to Darcy's formula, the loss of head due to friction in the pipe is (where f = Darcy's coefficient, l = Length of pipe, v = Velocity of liquid in pipe, and d = Diameter of pipe) (A) flv²/2gd (B) flv²/gd (C) 3flv²/2gd (D) 4flv²/2gd

Last Answer : Answer: Option D

The loss of head due to viscosity for laminar flow in pipes is (where d = Diameter of pipe, l = Length of pipe, v w = Specific weight of the flowing liquid) (A) 4 (B) 8 (C) 16 (D) 32

Description : The loss of head due to viscosity for laminar flow in pipes is (where d = Diameter of pipe, l = Length of pipe, v w = Specific weight of the flowing liquid) (A) 4 (B) 8 (C) 16 (D) 32

Last Answer : Answer: Option D

n a chemical factory where dyes are made, wet cake at 30 OC consisting of 60% moisture is put in a dryer to obtain an output having only 5% moisture, at atmospheric pressure. In each batch about 120 kgs of material is dried. a. The quantity of moisture removed per batch. b. What is the total quantity ( sensible & latent) of heat required to evaporate the moisture, if the latent heat of water is 540 kcal/kg at atmospheric conditions, Ignore heat absorbed by the solids c. Find the quantity of steam required for the drying process (per batch), if steam at 4 kg/cm2 is used for generating hot air in the dryer and the dryer efficiency is 80%. Latent heat of steam at 4 kg/cm2 is 520 kcal/kg.

Description : n a chemical factory where dyes are made, wet cake at 30 OC consisting of 60% moisture  is put in a dryer to obtain an output having only 5% moisture, at atmospheric pressure. In  each batch about 120 ... dryer and the dryer efficiency  is 80%. Latent heat of steam at 4 kg/cm2 is 520 kcal/kg.

Last Answer : Given that   Qty of material dried per batch - 120 Kgs  Moisture at inlet - 60% a. The quantity of moisture removed per batch.  Water quantity in a wet batch - 120 x 0.6 = 72 Kgs.  Quantity of bone dry ... - 48/0.95 = 50.5 Kgs.  Equivalent water in a dry batch - 50.5 - 48 = 2.5 Kgs.

The equivalent diameter for the annulus of a double pipe heat exchanger, whose inner pipe has fins on the outside is __________ compared to the same size pipes without fins. (A) More (B) Less (C) Same (D) Unpredictable

Description : The equivalent diameter for the annulus of a double pipe heat exchanger, whose inner pipe has fins on the outside is __________ compared to the same size pipes without fins. (A) More (B) Less (C) Same (D) Unpredictable

Last Answer : (B) Less

Pick out the wrong statement. (A) In process heat exchangers, saturated steam is preferred over the superheated steam (B) The maximum is the emissive power of a surface at a temperature T1 occurs at a wavelength of λ1 . If the surface temperature is halved, the maximum in the emissive power would occur at a wavelength of 0.5 λ1 (C) When a vertical plate is heated in infinite air environmental under natural convection conditions, the velocity profile in air, normal to the plate, exhibits a maximum

Description : Pick out the wrong statement. (A) In process heat exchangers, saturated steam is preferred over the superheated steam (B) The maximum is the emissive power of a surface at a temperature T1 ... under natural convection conditions, the velocity profile in air, normal to the plate, exhibits a maximum

Last Answer : (B) The maximum is the emissive power of a surface at a temperature T1 occurs at a wavelength of λ1 . If the surface temperature is halved, the maximum in the emissive power would occur at a wavelength of 0.5 λ1

Which is NOT a characteristic of emissivity?  A. It is high with most nonmetals  B. It is directly proportional to temperature  C. It is independent with the surface condition of the material  D. It is low with highly polished metals

Description : Which is NOT a characteristic of emissivity?  A. It is high with most nonmetals  B. It is directly proportional to temperature  C. It is independent with the surface condition of the material  D. It is low with highly polished metals

Last Answer : It is independent with the surface condition of the material

Recall homework 2 in which we calculated emissivity for a single layer atmosphere. If the atmosphere were to suddenly become a perfect emitter (i.e., if e = 1 rather than e = 0.8), what would happen to the surface temperature? (a) The surface temperature would be lower. (b) The surface temperature would be the same. (c) The surface temperature would be higher. (d) There would be initial warming followed by cooling as the planet moves toward radiative equilibrium.

Description : Recall homework 2 in which we calculated emissivity for a single layer atmosphere. If the atmosphere were to suddenly become a perfect emitter (i.e., if e = 1 rather than e = 0.8), ... . (d) There would be initial warming followed by cooling as the planet moves toward radiative equilibrium.

Last Answer : (c) The surface temperature would be higher.

Which of the following parameters are not required for evaluating volumetric efficiency of the compressor? a) Power b) Cylinder bore diameter c) Stroke length d) FAD

Description : Which of the following parameters are not required for evaluating volumetric efficiency of the compressor? a) Power b) Cylinder bore diameter c) Stroke length d) FAD

Last Answer : a) Power

Which of the following is the most widely used heat insulating material for pipelines carrying steam? (A) Tar dolomite bricks followed by asbestos (B) Fireclay refractory followed by aluminium sheet (C) Cotton followed by aluminium foil (D) 85% magnesia cement and glass wool

Description : Which of the following is the most widely used heat insulating material for pipelines carrying steam? (A) Tar dolomite bricks followed by asbestos (B) Fireclay refractory followed by aluminium sheet (C) Cotton followed by aluminium foil (D) 85% magnesia cement and glass wool

Last Answer : (D) 85% magnesia cement and glass wool

A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will (A) Increase (B) Decrease (C) Remain unaffected (D) May increase or decrease; depends on the thickness of each layer

Description : A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted ... ) Remain unaffected (D) May increase or decrease; depends on the thickness of each layer

Last Answer : Option C

LMTD for counter-flow and parallel flow heat exchanger will be the same, when the (A) Cold fluid is heated to a certain temperature by condensing steam (isothermal fluid) (B) Outlet temperature of both the hot and cold fluid are same (C) Outlet temperature of hot fluid is less than the outlet temperature of the cold fluid (D) None of these

Description : LMTD for counter-flow and parallel flow heat exchanger will be the same, when the (A) Cold fluid is heated to a certain temperature by condensing steam (isothermal fluid) (B) Outlet temperature of ... temperature of hot fluid is less than the outlet temperature of the cold fluid (D) None of these

Last Answer : (A) Cold fluid is heated to a certain temperature by condensing steam (isothermal fluid)

Out of 100 kcal/second of incident radiant energy on the surface of a thermally transparent body, 300 kcal/second is reflected back. If the transmissivity of the body is 0.25, the emissivity of the surface will be (A) 0.35 (B) 0.45 (C) 0.55 (D) 0.85

Description : Out of 100 kcal/second of incident radiant energy on the surface of a thermally transparent body, 300 kcal/second is reflected back. If the transmissivity of the body is 0.25, the emissivity of the surface will be (A) 0.35 (B) 0.45 (C) 0.55 (D) 0.85

Last Answer : (B) 0.45

Heat transfer rate to the stock/charge in the furnace does not depend upon the(A) Emissivity of the refractory walls(B) Size of the furnace(C) Use of waste heat recovery equipments(D) Thickness of the stock

Description : Heat transfer rate to the stock/charge in the furnace does not depend upon the (A) Emissivity of the refractory walls (B) Size of the furnace (C) Use of waste heat recovery equipments (D) Thickness of the stock

Last Answer : (C) Use of waste heat recovery equipments

Tar is a better fuel than furnace oil, because of its (A) Higher calorific value (B) Lower sulphur content (C) Higher emissivity (0.8-0.9) resulting in higher radiation heat transfer rate (D) Both (A) and (B)

Description : Tar is a better fuel than furnace oil, because of its (A) Higher calorific value (B) Lower sulphur content (C) Higher emissivity (0.8-0.9) resulting in higher radiation heat transfer rate (D) Both (A) and (B)

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

Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its (A) Emissivity factor is higher (B) Sulphur content is lower (C) Flue gas has lower dew point thereby facilitating more waste heat recovery (D) All (A), (B) and (C)

Description : Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its (A) Emissivity factor is higher (B) Sulphur content is lower (C) Flue gas has lower dew point thereby facilitating more waste heat recovery (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation will (A) Increase (B) Decrease (C) Remain unchanged (D) Either increase or decrease; depends on the coolant flow rate

Description : In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation ... Decrease (C) Remain unchanged (D) Either increase or decrease; depends on the coolant flow rate

Last Answer : (C) Remain unchanged

What is the Water Regulations the maximum permissible length of dead leg without insulation from the top of a hot water cylinder to the outlet tap for a 22mm pipe?

Description : What is the Water Regulations the maximum permissible length of dead leg without insulation from the top of a hot water cylinder to the outlet tap for a 22mm pipe?

Last Answer : 8m