The local surface conductance for laminar film condensation on vertical surface is (where, t = film thickness)

kg of solids (on dry basis) is subjected to a drying process for a period ofseconds. The drying occurs in the constant rate period with the drying rate as, N_c = 0.5 x 10^-3 kg/m².s. The initial moisture content of the solid is 0.2 kg moisture/kg dry solid. The interfacial area available for drying is 4 m²/kg of dry solid. The moisture content at the end of the drying period is (in kg moisture/kg dry solid)

The purpose of providing a 'catchall' in the vapor line of an evaporator is to

With increase in temperature, the thermal conductivity of most liquids

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

Crystallisation of solids from a homogeneous solution is a/an __________ process.

The sum of reflectivity and absorptivity for an opaque body is equal to

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

With increase in temperature, the thermal conductivity of steel

A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter 'd'. For a fixed mass flow rate, the tube side heat transfer co-efficient for turbulent flow conditions is proportional to

Prandtl and Reynolds analogy are same, when Prandtl number is

The absorptivity of a grey body at a given temperature __________ with increasing wavelength of radiation.

If average heat transfer co-efficient is h_a and the local coefficient at the end of the plate is h_l then in case of heat transfer to a fluid flowing over a flat plate, heated over its entire length

Which of the following has the minimum thermal conductivity ?

Radiant energy received by a body is proportional to (where, d = the distance between the object emitting radiation and that receiving it.)

The purpose of floating head in a heat exchanger is to

Heat transfer co-efficient (h₁) for liquids increases with

In case of a vertical tube evaporator, with increase in the liquor level, the

What is the thermal conductivity of a perfect heat insulator ?

Duhring rule is important in solving problems on

For concentrating an aqueous solution of a material like anhydrous Na2SOwhose solubility decreases with rise in temperature, the most suitable evaporator is a __________ evaporator.

A tank painted with which of the following coloured paints, would heat up maximum by radiation from sun ?

Which is the most suitable for cold viscous feed?

h.D/K is called the __________ number.

Nucleate boiling is promoted

Which of the following is not concerned with the heat transfer?

A multiple effect evaporator has a capacity to processkg of solid caustic soda per day, when it is concentrating fromtosolids. The water evaporated in kg per day is

The film thickness for laminar film condensation on vertical surface __________ from top to bottom.

Which of the following forced convection heat transfer equation accounts for the liquid viscosity effect for viscous liquids ?

Heat transfer occurs by natural convection because change in temperature causes difference in

jH factor for heat transfer is not a function of the __________ number.

In a heat exchanger, one transfer unit means

Kg of liquid at 30°C in a well stirred vessel has to be heated to 120°C, using immersed coils carrying condensing steam at 150°C. The area of the steam coils is 1.2 m² and the overall heat transfer co-efficient to the liquid isW/m².°C. Assuming negligible heat loss to the surrounding and specific heat capacity of the liquid to be 4 kJ/kg.°C, the time taken for the liquid to reach desired temperature will be

A diathermaneous substance __________ the thermal radiation completely.

A hot body will radiate heat most rapidly, if its surface is

The ratio of total radiating power to the absorptivity of the body depends upon the __________ as per Kirchoffs law.

In a shell and tube heat exchanger, the height ofpercent cut baffles is equal to (where, D = inside diameter of shell)

Circulation pump is located below the evaporater to

The interchange factor for radiation heat transfer from surface 'x' to surface 'y' in case of an infinite parallel planes with emis-sivities εx & εy is given by

The separation of liquid droplets from the vapor is done by a/an __________ , in the evaporators.

Dropwise condensation is promoted on a/an __________ surface.

Prandtl number is the ratio of

Conductance is given by(where, x = thickness, A = heat flow area, K = thermal conductivity.)

In forced circulation, the heating element is injected

If all the conditions and dimensions are same, then the ratio of velocity through the tubes of a double pass heat exchanger to that through the single pass heat exchanger is

Latent heat absorbed by 1 lb of water at 212°F, when it is changed to steam at 212°F, may be around __________ BTU.

In counter flow compared to parallel flow,

Value of Prandtl number for water ranges from

Heat transfer in the laminar sublayer in case of a liquid flowing through a pipe, is mostly by

Viscosity of gases __________ with increase in temperature.