LMTD can't be used as such without a correction factor for the (A) Multipass heat exchanger (B) Baffled heat exchanger (C) Condensation of mixed vapour in a condenser (D) All (A) (B) and (C)

LMTD can't be used as such without a correction factor for the
(A) Multipass heat exchanger
(B) Baffled heat exchanger
(C) Condensation of mixed vapour in a condenser
(D) All (A) (B) and (C)
by

1 Answer

Answer :

(D) All (A) (B) and (C)
by

Related questions

For a multipass shell and tube heat exchanger, the LMTD correction factor is always (A) 1 (B) > 1 (C) < 1 (D) Between 1 & 2

Description : For a multipass shell and tube heat exchanger, the LMTD correction factor is always (A) 1 (B) > 1 (C) < 1 (D) Between 1 & 2

Last Answer : (C) < 1

LMTD correction factor which is to be applied for a cross-flow heat exchanger increases with increase in the number of shell passes. Its value for a single pass cross flow heat exchanger is (A) 0 (B) 1 (C) > 1 (D) < 1

Description : LMTD correction factor which is to be applied for a cross-flow heat exchanger increases with increase in the number of shell passes. Its value for a single pass cross flow heat exchanger is (A) 0 (B) 1 (C) > 1 (D) < 1

Last Answer : (D) < 1

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

It is not recommended to use a 1-2 shell and tube heat exchanger for a particular heat duty, whenever the LMTD correction factor is (A) > 0.75 (B) < 0.75 (C) < 0.50 (D) < 0.25

Description : It is not recommended to use a 1-2 shell and tube heat exchanger for a particular heat duty, whenever the LMTD correction factor is (A) > 0.75 (B) < 0.75 (C) < 0.50 (D) < 0.25

Last Answer : (B) < 0.75

Fouling factor' used in the design of a multipass shell and tube heat exchanger is a (A) Non-dimensional factor (B) Factor of safety

Description : Fouling factor' used in the design of a multipass shell and tube heat exchanger is a (A) Non-dimensional factor (B) Factor of safety

Last Answer : (B) Factor of safety

In case of a multipass shell and tube heat exchanger, providing a baffle on the shell side __________ the heat transfer rate. (A) Increases (B) Decreases (C) Does not affect (D) May increase or decrease, depends on the type of baffle

Description : In case of a multipass shell and tube heat exchanger, providing a baffle on the shell side __________ the heat transfer rate. (A) Increases (B) Decreases (C) Does not affect (D) May increase or decrease, depends on the type of baffle

Last Answer : (A) Increases

In a multipass shell and tube heat exchanger, tube side return pressure loss is equal to __________ the velocity head. (A) Twice (B) Four times (C) Square root of (D) Square of

Description : In a multipass shell and tube heat exchanger, tube side return pressure loss is equal to __________ the velocity head. (A) Twice (B) Four times (C) Square root of (D) Square of

Last Answer : (B) Four times

Which of the following parameters is increased by use of finned tube in a multipass shell and tube heat exchanger? (A) Tube side pressure drop and the heat transfer rate (B) Convective heat transfer co-efficient (C) Effective tube surface area for convective heat transfer (D) All (A) (B) and (C)

Description : Which of the following parameters is increased by use of finned tube in a multipass shell and tube heat exchanger? (A) Tube side pressure drop and the heat transfer rate (B) Convective heat transfer co-efficient (C) Effective tube surface area for convective heat transfer (D) All (A) (B) and (C)

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

Tube expansion allowances exist in __________ heat exchanger. (A) Multipass fixed tube sheet (B) U-tube (C) Single pass fixed tube sheet (D) None of these

Description : Tube expansion allowances exist in __________ heat exchanger. (A) Multipass fixed tube sheet (B) U-tube (C) Single pass fixed tube sheet (D) None of these

Last Answer : (B) U-tube

The ratio of velocity head to tube side return loss in case of a multipass shell and tube heat exchanger is (A) 2 (B) 1/2 (C) 4 (D) 1/4

Description : The ratio of velocity head to tube side return loss in case of a multipass shell and tube heat exchanger is (A) 2 (B) 1/2 (C) 4 (D) 1/4

Last Answer : (D) 1/4

In case of a multipass shell and tube heat exchanger, the temperature drop in the fluid (A) Is inversely proportional to the resistance across which the drop occurs (B) And the wall are proportional to individual resistances (C) And the wall is not related (D) None of these

Description : In case of a multipass shell and tube heat exchanger, the temperature drop in the fluid (A) Is inversely proportional to the resistance across which the drop occurs (B) And the wall are proportional to individual resistances (C) And the wall is not related (D) None of these

Last Answer : (B) And the wall are proportional to individual resistances

For the same heat load and mass flow rate in the tube side of a shell and tube heat exchanger, one may use multipass on the tube side, because it (A) Decreases the pressure drop (B) Decreases the outlet temperature of cooling medium (C) Increases the overall heat transfer coefficient (D) None of these

Description : For the same heat load and mass flow rate in the tube side of a shell and tube heat exchanger, one may use multipass on the tube side, because it (A) Decreases the pressure drop (B) ... the outlet temperature of cooling medium (C) Increases the overall heat transfer coefficient (D) None of these

Last Answer : (C) Increases the overall heat transfer coefficient

In a 1-1 concurrent heat exchanger, if the tube side fluid outlet temperature is equal to the shell side fluid outlet temperature, then the LMTD is (A) ∞ (B) 0 (C) Equal to the difference between hot and cold fluids inlet temperature (D) Equal to the difference between hot fluid inlet temperature and cold fluid outlet temperature

Description : In a 1-1 concurrent heat exchanger, if the tube side fluid outlet temperature is equal to the shell side fluid outlet temperature, then the LMTD is (A) ∞ (B) 0 ... temperature (D) Equal to the difference between hot fluid inlet temperature and cold fluid outlet temperature

Last Answer : (B) 0

The outlet temperature of cooling water in a heat exchanger is generally not allowed to exceed above 50°C in industrial practice mainly to avoid (A) Its evaporation loss (B) Excessive corrosion (C) Uneconomic LMTD (D) Decrease in heat exchanger efficiency

Description : The outlet temperature of cooling water in a heat exchanger is generally not allowed to exceed above 50°C in industrial practice mainly to avoid (A) Its evaporation loss (B) Excessive corrosion (C) Uneconomic LMTD (D) Decrease in heat exchanger efficiency

Last Answer : (B) Excessive corrosion

In a parallel flow heat exchanger, if the outlet temperature of hot and cold fluids are the same, then the log mean temperature difference (LMTD) is (A) Minimum (B) Maximum (C) Zero (D) Infinity

Description : In a parallel flow heat exchanger, if the outlet temperature of hot and cold fluids are the same, then the log mean temperature difference (LMTD) is (A) Minimum (B) Maximum (C) Zero (D) Infinity

Last Answer : (C) Zero

Log mean temperature difference (LMTD) cannot be used, if (A) Heat transfer co-efficient over the entire heat exchanger is not constant (B) There exists an unsteady state (C) The heat capacity is not constant and there is a phase change (D) None of these

Description : Log mean temperature difference (LMTD) cannot be used, if (A) Heat transfer co-efficient over the entire heat exchanger is not constant (B) There exists an unsteady state (C) The heat capacity is not constant and there is a phase change (D) None of these

Last Answer : (D) None of these

In a liquid-liquid heat exchanger, for the same process temperature, the ratio of the LMTD in parallel flow to the LMTD in counter flow is always (A) < 1 (B) > 1 (C) 1 (D) ∞

Description : In a liquid-liquid heat exchanger, for the same process temperature, the ratio of the LMTD in parallel flow to the LMTD in counter flow is always (A) < 1 (B) > 1 (C) 1 (D) ∞

Last Answer : (A) < 1

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)

In a heat exchanger, the rate of heat transfer from the hot fluid to the cold fluid (A) Varies directly as the area and the LMTD (B) Directly proportional to LMTD and inversely proportional to the area (C) Varies as square of the area (D) None of these

Description : In a heat exchanger, the rate of heat transfer from the hot fluid to the cold fluid (A) Varies directly as the area and the LMTD (B) Directly proportional to LMTD and inversely proportional to the area (C) Varies as square of the area (D) None of these

Last Answer : (A) Varies directly as the area and the LMTD

For a heat exchanger, will the overall heat transfer coefficient increase along with an increase in LMTD (log mean temperature difference) around the unit?

Description : For a heat exchanger, will the overall heat transfer coefficient increase along with an increase in LMTD (log mean temperature difference) around the unit?

Last Answer : The overall heat transfer coefficient is generally weakly dependent on temperature. As the temperatures of the fluids change, the degree to which the overall heat transfer coefficient will be affected depends ... with temperature as I've noted and the U-value will decrease over time with fouling).

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'

Correction is applied to LMTD for __________ flow. (A) Parallel (B) Counter (C) Cross (D) None of these

Description : Correction is applied to LMTD for __________ flow. (A) Parallel (B) Counter (C) Cross (D) None of these

Last Answer : (C) Cross

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 (B) Film co-efficient for vaporisation decreases as a result of vapor binding (C) In industrial practice, sub-cooling of condensate is required, when thecondensate is a volatile liquid and is to be transferred for storage(D) Overall heat transfer co-efficient in a heat exchanger is controlled by thevalue of the film co-efficient, which is higher

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

A dephlegmator is a (A) Total condenser (B) Vacuum evaporator (C) Partial condenser (D) Double pipe heat exchanger

Description : A dephlegmator is a (A) Total condenser (B) Vacuum evaporator (C) Partial condenser (D) Double pipe heat exchanger

Last Answer : (C) Partial condenser

Small scale evaporation is done in a (A) Heat exchanger (B) Condenser(C) Multiple effect evaporator(D) Steam jacketed kettle

Description : Small scale evaporation is done in a (A) Heat exchanger (B) Condenser (C) Multiple effect evaporator (D) Steam jacketed kettle

Last Answer : (D) Steam jacketed kettle

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 exchanger, when the (A) Higher condensing film co-efficient is desired (B) Condensate is corrosive in nature (C) Lower pressure drop through the exchanger is desired (D) Temperature of the incoming vapor is very high Answer: Option B

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

Pick out the wrong statement. (A) Heat transfer by radiation cannot occur across an absolute volume (B) In case of a shell and tube heat exchanger, the pressure drop through the shell is proportional to the number of times the fluid crosses the bundle between baffles (C) Propagation velocity for travel of heat radiation through vacuum is equal to the velocity of the light (D) The amount of heat involved in the condensation or vaporisation of 1 kg of a fluid is the same

Description : Pick out the wrong statement. (A) Heat transfer by radiation cannot occur across an absolute volume (B) In case of a shell and tube heat exchanger, the pressure drop through the shell is ... The amount of heat involved in the condensation or vaporisation of 1 kg of a fluid is the same

Last Answer : (A) Heat transfer by radiation cannot occur across an absolute volume

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

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 calculations (Δt) weighted is used in place of Δt, when it involves more than one sequence of heating or cooling i.e., desuperheating & condensation or condensation & sub-cooling (C) Heat transfer co-efficient during nucleate boiling is not influenced by the agitation imparted (D) In case of short tube vertical evaporators, area of central downtake is about 50 to 100% of the total tube cross-sectional area

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

Explain construction and working of shell and tube type heat exchanger. A ice plant producing 2000 Kg ice per day required the condenser. Suggest the type of condenser with justification.

Description : Explain construction and working of shell and tube type heat exchanger. A ice plant producing 2000 Kg ice per day required the condenser. Suggest the type of condenser with justification. 

Last Answer : Shell and tube heat exchanger consist of a bundle of round tubes placed inside the cylindrical shell.Tube axis parallel to that of shell. One fluid inside the tubes while the other over ... of heat rejection by the evaporation of water into an air stream traveling across the condensing coil.

The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is (A) Less pronounced (B) More pronounced (C) Equal (D) Data insufficient, can't be predicted

Description : The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is (A) Less pronounced (B) More pronounced (C) Equal (D) Data insufficient, can't be predicted

Last Answer : (B) More pronounced

In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respectively, the Carnot COP will be (A) 5.2 (B) 6.2 (C) 0.168 (D) Data insufficient, can't be found out

Description : In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respectively, the Carnot COP will be (A) 5.2 (B) 6.2 (C) 0.168 (D) Data insufficient, can't be found out

Last Answer : A) 5.2

An ideal liquid refrigerant should (A) Not have a sub-atmospheric vapour pressure at the temperature in the refrigerator coils (B) Not have unduly high vapour pressure at the condenser temperature (C) Both (A) and (B) (D) Have low specific heat

Description : An ideal liquid refrigerant should (A) Not have a sub-atmospheric vapour pressure at the temperature in the refrigerator coils (B) Not have unduly high vapour pressure at the condenser temperature (C) Both (A) and (B) (D) Have low specific heat

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

Use of excess of combustion air in the combustion of fuels results in (A) Heat losses (B) Long flame (C) Condensation of water vapour from the fuel gas (D) None of these

Description : Use of excess of combustion air in the combustion of fuels results in (A) Heat losses (B) Long flame (C) Condensation of water vapour from the fuel gas (D) None of these

Last Answer : (A) Heat losses

Pick out the correct statement about the condensation. (A) Filmwise condensation gives a lower heat transfer rate than the dropwise condensation (B) Suitable coating or vapour additive is used to promote film wise condensation (C) If a condensing liquid does not wet the surface dropwise, even then condensation will take place on it (D) Reynolds number of condensing liquid is based on its mass flow rate

Description : Pick out the correct statement about the condensation. (A) Filmwise condensation gives a lower heat transfer rate than the dropwise condensation (B) Suitable coating or vapour additive is used to promote film ... place on it (D) Reynolds number of condensing liquid is based on its mass flow rate

Last Answer : (B) Suitable coating or vapour additive is used to promote film wise condensation

Multipass heat exchangers are used (A) Because of simplicity of fabrication (B) For low heat load (C) To obtain higher heat transfer co-efficient and shorter tube (D) To reduce the pressure drop

Description : Multipass heat exchangers are used (A) Because of simplicity of fabrication (B) For low heat load (C) To obtain higher heat transfer co-efficient and shorter tube (D) To reduce the pressure drop

Last Answer : (C) To obtain higher heat transfer co-efficient and shorter tube

When air passes through silica gel, A. it absorbs water vapour molecules B. latent heat of condensation is released C.dbt of air increases D. all of the mentioned

Description : When air passes through silica gel, A. it absorbs water vapour molecules B. latent heat of condensation is released C.dbt of air increases D. all of the mentioned

Last Answer : ANSWER : D

Saturated steam at 1 atm is discharged from a turbine at 1200 kg/h. Superheated steam at 300 0C and 1 atm is needed as a feed to a heat exchanger. To produce it, the turbine discharge stream is mixed with superheated steam at 400 0C, 1 atm and specific volume of 3.11 m 3 /kg. Calculate the amount of superheated steam at 300 0C produced and the volumetric flow rate of the 400 0C steam.

Description : Saturated steam at 1 atm is discharged from a turbine at 1200 kg/h. Superheated steam at 300 0C  and 1 atm is needed as a feed to a heat exchanger. To produce it, the turbine discharge ... amount of superheated steam at 300 0C produced and the volumetric flow rate of the  400 0C steam.

Last Answer : Solution 1. Mass balance of water 1200 + m1 = m2 ………………………………………… (1) …………………….1 mark 2. Energy balance (1200 kg/h)(2676 kJ/kg) + m1(3278 kJ/kg)

Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in (A) Increased COP (B) Same COP (C) Decreased COP (D) Increased or decreased COP; depending upon the type of refrigerant

Description : Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in (A) Increased COP (B) Same COP (C) Decreased COP (D) Increased or decreased COP; depending upon the type of refrigerant

Last Answer : (A) Increased COP

5. In "Imperial Smelting Process" for extraction of zinc, zinc vapour thus produced is quenched in the external condenser by the use of the following: (A) Jet of water at high pressure (B) Blast of air (C) Mixture of water and air (D) Rain of molten lead

Description : 5. In "Imperial Smelting Process" for extraction of zinc, zinc vapour thus produced is quenched in the external condenser by the use of the following: (A) Jet of water at high pressure (B) Blast of air (C) Mixture of water and air (D) Rain of molten lead

Last Answer : Option D

In counter flow compared to parallel flow, (A) LMTD is greater (B) Less surface area is required for a given heat transfer rate (C) Both (A) and (B) (D) More surface area is required for a given heat transfer rate

Description : In counter flow compared to parallel flow, (A) LMTD is greater (B) Less surface area is required for a given heat transfer rate (C) Both (A) and (B) (D) More surface area is required for a given heat transfer rate

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

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 deviationin practice ?(A) Constant overall heat transfer co-efficient.(B) Constant rate of fluid flow(C) Constant specific heat(D) No partial phase change in the system

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

For a turbine agitated and baffled tank, operating at low Reynold's number (based on impeller diameter), the power number (Np ) varies with NRe as (A) Np ∝ NRe (B) Np ∝ √NRe (C) Np → constan(D) Np ∝ 1/NRe

Description : For a turbine agitated and baffled tank, operating at low Reynold's number (based on impeller diameter), the power number (Np ) varies with NRe as (A) Np ∝ NRe (B) Np ∝ √NRe (C) Np → constan (D) Np ∝ 1/NRe

Last Answer : (D) Np ∝ 1/NRe

During agitation of liquids, the (A) Froude number is independent for the curves between power number and Reynolds number in baffled system (B) Power number becomes independent of impellers Reynolds number at high Reynolds number, but is dependent on the geometry of the impeller (C) Froude number is used to account for the effect of surface (e.g., the centre vortex) on the power number (D) All (A), (B) and (C)

Description : During agitation of liquids, the (A) Froude number is independent for the curves between power number and Reynolds number in baffled system (B) Power number becomes independent of impellers Reynolds number at high Reynolds number, ... , the centre vortex) on the power number (D) All (A), (B) and (C)

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

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, the shell pressure drop is maximum for orifice baffles (C) S.I. unit of fouling factor is Watt/m2 .°K (D) Longitudinal fins are used in extended surface heat exchangers, when the direction of fluid flow is parallel to the axis of the tube

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

Fouling factor for a heat exchanger is given by (where, U1 = heat transfer co-efficient of dirty surface U2 = heat transfer co-efficient of clean surface). (A) U1 - U2 (B) 1/U1 - 1/U2 (C) 1/U2 - 1/U1 (D) U2 - U1

Description : Fouling factor for a heat exchanger is given by (where, U1 = heat transfer co-efficient of dirty surface U2 = heat transfer co-efficient of clean surface). (A) U1 - U2 (B) 1/U1 - 1/U2 (C) 1/U2 - 1/U1 (D) U2 - U1

Last Answer : (B) 1/U1 - 1/U2

How can one estimate how the friction factor changes in heat exchanger tubes with a change in temperature?

Description : How can one estimate how the friction factor changes in heat exchanger tubes with a change in temperature?

Last Answer : Seider and Tate recommended the following for determine friction factors inside heat exchanger tubes with varying temperatures: First, determine the average, bulk mean temperature in the processing line. For example if ... 0.11 and for heating, it's divided by (bulk viscosity/wall viscosity)0.17.

In a shell and tube heat exchanger, the shell side fluid velocity can’t be changed by changing the (A) Tube layout (B) Tube diameter (C) Tube pitch (D) Number of baffles

Description : In a shell and tube heat exchanger, the shell side fluid velocity can’t be changed by changing the (A) Tube layout (B) Tube diameter (C) Tube pitch (D) Number of baffles

Last Answer : (B) Tube diameter

Condensation of a vapour-gas mixture just begins, when (where, p = partial pressure of the vapour P = vapour pressure of the liquid). (A) p = P (B) p >>P (C) p < P (D) p << P

Description : Condensation of a vapour-gas mixture just begins, when (where, p = partial pressure of the vapour P = vapour pressure of the liquid). (A) p = P (B) p >>P (C) p < P (D) p

Last Answer : (A) p = P

Presence of a non-condensing gas in a condensing vapour (A) Increases the rate of condensation (B) Decreases thermal resistance (C) Is desirable to increase the film co-efficient (D) None of these

Description : Presence of a non-condensing gas in a condensing vapour (A) Increases the rate of condensation (B) Decreases thermal resistance (C) Is desirable to increase the film co-efficient (D) None of these

Last Answer : (D) None of these