A process stream of dilute aqueous solution flowing at the rate ofKg.s-1 is to be heated. Steam condensate at 95°C is available for heating purpose, also at a rate ofKg.s-1. A 1 - 1 shell and tube heat exchanger is available. The best arrangement is
Pick out the wrong statement.
Baffles in the shell side of a shell and tube heat exchanger
In case of vertical tube evaporator, with increase in liquor level, the overall heat transfer co-efficient
Heat waves
Air is best heated with steam in a heat exchanger of
Fourier's law applies to the heat transfer by
Heat produced when a steady state current, I passes through an electrical conductor having resistance, 'R' is
Economy of a multiple effect evaporator is not influenced much by the
Air is to be heated by condensing steam. Two heat exchangers are available (i) a shell and tube heat exchanger and (ii) a finned tube heat exchanger. Tube side heat transfer area are equal in both the cases. The recommended arrangement is
The steam ejector is used to
Which of the following is generally considered as opaque surface towards radiations?
Fourier's law applies to the heat transfer by
Increasing the liquor level in the evaporator results in the
For shell and tube heat exchanger, with increasing heat transfer area, the purchased cost per unit heat transfer area
Black liquor generated during paper manufacture is concentrated in a
The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a refrigerator (COP)R and the co-efficient of performance as a heat pump (COP)HP are
Pick out the correct equation.
Choose the correct equation.
In a gas-liquid shell and tube heat exchanger, the
Which of the following has the minimum absorptivity ?
Which is the most suitable for the concentration of foamy & frothy liquors ?
Boiling point elevation of an ideal solution
A black body when hot, emits heat radiation of __________ wavelengths.
Steam side heat transfer co-efficient in an evaporator is in the range of __________ kcal/hr.m2°C.
Correction is applied to LMTD for __________ flow.
The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe whose surface temperature remains constant is
The rate of heat transfer is a product of overall heat transfer co-efficient, the difference in temperature and the
Which of the following has the lowest overall heat transfer co-efficient ?
A composite wall consists of two plates A and B placed in series normal to the flow of heat. The thermal conductivities are kA and kB and the specific heat capacities are CPA and CPB for plates A and B respectively. Plate B has twice the thickness of plate A. At steady state, the temperature difference across plate A is greater than that across plate B, when
If h1 = inner film co-efficient and /h2 = outer film co-efficient, then the overall heat transfer co-efficient is
Low thermal conductivity of heat insulating materials is due to its
Multiple effect evaporators ar used to
The value of Stefan-Boltazman constant in SI unit is
Sensible heat of hot industrial flue gases can not be recovered by a/an
Vibrations in the tubes of a shell and tube heat exchanger is induced due to the
One kilogram of water at 0°C is changed to superheated steam of one atm pressure andC. The major heat consumption in the process will be to
The most conducive surface for dropwise condensation to occur is the __________ surface.
In an interphase heat transfer process, the equilibrium state corresponds to equality of temperature in the two phases, while the condition for equilibrium in an interphase mass transfer process is equality of
The unit of heat transfer co-efficient is
The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h0 = heat transfer coefficient at the outer surface)
Heat transfer by conduction in the turbulent core of a fluid flowing through a heated pipe is negligible, if the value of Prandtl number is
Calburn analogy is applicable for the value of Prandtl number from
Small scale evaporation is done in a
For turbulent flow in a tube, the heat transfer co-efficient is obtained from the Dittus-Boelter correlation. If the tube diameter is halved and the flow rate is doubled, then the heat transfer co-efficient will change by a factor of
The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances,andcm thick with thermal conductivities of 0.and 0.1 W.m-1.°C-1 respectively. The ambient air is at 30°C and the heat transfer co-efficient between the outer surface of wall and air isW.m-2.°C-1. The rate of heat loss from the outer surface in W.m-2is
Radiator of an automobile engine is a __________ type of heat exchanger.
In pipe flow, heat is transferred from hot wall to the liquid by
One kilogram of water at 0°C is changed to superheated steam of one atm pressure andC. The major heat consumption in the process will be to
Heat exchanger tubes are never made of