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Chemical Heat Transfer
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For small temperature difference, the heat transfer rate as per Newton’s law of cooling is proportional to (where, Δt = excess temperature) ?
Related MCQs
Overall heat transfer co-efficient for cooling of hydrocarbons by water is about__________?
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In evaporators, lowering the feed temperature__________?
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Correction is applied to LMTD for __________ flow?
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Crystal size in a continuous crystalliser depends upon the__________?
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Black liquor generated during paper manufacture is concentrated in a__________?
What is Nusselt number ?
In the equation Q = UAΔt; Δt is__________?
For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in__________?
Hot water (0.01 m3 /min) enters the tube side of a counter current shell and tube heat exchanger at 80°C and leaves at 50°C. Cold oil (0.05 m3/min) of density 800 kg/m3 and specific heat of 2 kJ/kg.K enters at 20°C. The log mean temperature difference in °C is approximately ?
Graetz number is given by__________?
Reynold’s analogy states that__________?
Which of the following has the minimum thermal conductivity ?
For an ideal black body__________?
For concentrating an aqueous solution of a material like anhydrous Na2SO4, whose solubility decreases with rise in temperature, the most suitable evaporator is a __________ evaporator?
Leidenfrost point is a term concerned with the__________?
Which of the following is not used as a medium for high temperature heating ?
The inside heat transfer co-efficient in case of turbulent flow of liquid in the tube side in a 1-2 shell and tube heat exchanger is increased by __________ times, when the number of tube passes is increased to 8?
In regenerative air preheater (as practised in heating of coke ovens), the heat is transferred__________?
A multiple effect evaporator has a capacity to process 4000 kg of solid caustic soda per day, when it is concentrating from 10% to 25% solids. The water evaporated in kg per day is__________?
The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe whose surface temperature remains constant is__________?
Which characteristic of a fluid is not important in deciding its route in a shell and tube heat exchanger ?
What is the absorptivity of a black body?
Economy of a multiple effect evaporator is not influenced much by the__________?
Asymptotic conditions is reached, when for a fluid flowing in laminar flow through a long tube__________?
In case of evaporators, liquid entrainment results primarily due to__________?
Heat exchangers operating, when the asymptotic range is reached, ?
In counter flow compared to parallel flow, ?
Mode of heat transfer involved in the cooling of air cooled internal combustion engine is__________?
In a single effect evaporator, the economy is__________?
Small scale evaporation is done in a__________?
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__________?
Low thermal conductivity of heat insulating materials is due to its__________?
Low thermal conductivity of heat insulating materials is due to its__________?
For small temperature difference, the heat transfer rate as per Newton’s law of cooling is proportional to (where, Δt = excess temperature) ?
A. Δt
B. Δt2
C. Δt3
D. √(Δt)
Correct Answer:
Δt
✔
Last Updated:
March 03, 2019