Flashcard on Heat Exchanger

Front

Which of the following is not the part of shell & tube heat exchanger? Baffles, Guide rod, Tube sheets, Vacuum pump

Back

Vacuum pump

Answer explanation

A vacuum pump is not a component of a shell & tube heat exchanger. The main parts include baffles, guide rods, and tube sheets, which help in the heat transfer process.

Front

In a sheets & tube heat exchanger the flow pattern is usually________________.

Back

Concurrent at a part and counter current at the other.

Answer explanation

In a sheets & tube heat exchanger, the flow pattern is often a combination of concurrent flow in some sections and counter current in others, allowing for efficient heat transfer across varying temperature gradients.

Front

In a shell and tube heat exchanger, sometimes flow regimes cannot be expressed as concurrent or counter-current.

Back

False

Answer explanation

The statement is false because in a shell and tube heat exchanger, flow regimes are typically classified as either concurrent or counter-current. Other configurations do not exist in standard practice.

Front

The purpose of floating head in a heat exchanger is to

Back

Avoid buckling of tubes.

Answer explanation

The floating head in a heat exchanger is designed to avoid buckling of tubes due to thermal expansion and contraction. This feature allows for movement without damaging the tube structure, ensuring efficient operation.

Front

Baffle spacing should be less than the inside diameter of the shell.

Back

True

Answer explanation

True. Baffle spacing must be less than the inside diameter of the shell to ensure proper flow distribution and prevent dead zones, which can affect the efficiency of heat exchangers.

Front

A 2-4 heat exchanger involves______________.

Back

Only parallel-flow of fluids.

Answer explanation

A 2-4 heat exchanger specifically utilizes parallel-flow of fluids, where both fluids move in the same direction, allowing for effective heat transfer. Counter-flow is not applicable in this configuration.

Front

The main function of baffles provided in a shell and tube heat exchanger is to

Back

Enhance turbulence, hold tube in place, and facilitate the cleaning of the outer tube surface.

Answer explanation

Baffles in a shell and tube heat exchanger serve multiple functions: they enhance turbulence for better heat transfer, hold tubes in place, and facilitate cleaning of the outer tube surface. Thus, the correct answer is 'All of these'.

Front

Baffle in the shell side of a shell and tube heat exchanger____________.

Back

Decreased the shell side heat transfer Co-efficient.

Answer explanation

Baffles in the shell side of a heat exchanger disrupt flow patterns, leading to increased turbulence but can also create dead zones. This can reduce the overall heat transfer coefficient, hence the correct answer is that it decreased the shell side heat transfer coefficient.

Front

Shell side pressure drop in a shell and tube heat exchanger does not depend upon the: Baffles spacing, Shell diameter, Tube Diameter, None

Back

None

Answer explanation

The shell side pressure drop in a shell and tube heat exchanger is influenced by factors like baffle spacing, shell diameter, and tube diameter. Therefore, the correct answer is 'None' as all options affect the pressure drop.

Front

In a shell and tube heat exchanger the shell side fluid velocity can't be changed by changing the_______?

Back

Tube diameter

Answer explanation

The shell side fluid velocity is primarily influenced by the flow area and the fluid properties. Changing the tube diameter affects the flow area but does not directly change the shell side fluid velocity, unlike tube layout.