March 2019 - Page 823 of 895 -

Open pan evaporators are preferred to be used, when the solution to be concentrated is_________________?

Chemical Heat Transfer / admin

Open pan evaporators are preferred to be used, when the solution to be concentrated is_________________?

A. Scaling
B. Highly viscous
C. Corrosive
D. Salty

Open pan evaporators are preferred to be used, when the solution to be concentrated is_________________? Read More »

Chemical Heat Transfer

When warm and cold liquids are mixed, the heat transfer is mainly by_______________?

Chemical Heat Transfer / admin

When warm and cold liquids are mixed, the heat transfer is mainly by_______________?

A. Conduction
B. Convection
C. Radiation
D. Both A. & C.

When warm and cold liquids are mixed, the heat transfer is mainly by_______________? Read More »

Chemical Heat Transfer

At constant temperature, the thermal conductivities of gases _____________ with rise in pressure?

Chemical Heat Transfer / admin

At constant temperature, the thermal conductivities of gases _____________ with rise in pressure?

A. Decrease
B. Increase
C. Remain unchanged
D. May increase or decrease; depends on the pressure

At constant temperature, the thermal conductivities of gases _____________ with rise in pressure? Read More »

Chemical Heat Transfer

A single pass air heater is connected to a two pass unit. For the air flow rate and other conditions remaining the same, the film heat transfer co-efficient for air will vary in the ratio of__________________?

Chemical Heat Transfer / admin

A single pass air heater is connected to a two pass unit. For the air flow rate and other conditions remaining the same, the film heat transfer co-efficient for air will vary in the ratio of__________________?

A. 2
B. 20.8
C. 20.2
D. 20.5

Chemical Heat Transfer

It is not preferable to use superheated steam in evaporators, because of its very_________________?

Chemical Heat Transfer / admin

It is not preferable to use superheated steam in evaporators, because of its very_________________?

A. High temperature
B. High pressure
C. Low film co-efficient
D. None of these

It is not preferable to use superheated steam in evaporators, because of its very_________________? Read More »

Chemical Heat Transfer

_____________ heat exchanger is used for chilling oil to be dewaxed?

Chemical Heat Transfer / admin

_____________ heat exchanger is used for chilling oil to be dewaxed?

A. U-tube
B. Double pipe
C. Fixed tube
D. Floating head

_____________ heat exchanger is used for chilling oil to be dewaxed? Read More »

Chemical Heat Transfer

If heat transfer rate varies with the time, it is termed as__________________?

Chemical Heat Transfer / admin

If heat transfer rate varies with the time, it is termed as__________________?

A. Forced convection
B. Steady state conduction
C. Monochromatic radiation
D. None of these

If heat transfer rate varies with the time, it is termed as__________________? Read More »

Chemical Heat Transfer

The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 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 is 20 W.m-2.°C-1. The rate of heat loss from the outer surface in W.m-2is__________________?

Chemical Heat Transfer / admin

The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 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 is 20 W.m-2.°C-1. The rate of heat loss from the outer surface in W.m-2is__________________?

A. 165.4
B. 167.5
C. 172.5
D. 175

Chemical Heat Transfer