4. If a single tube pass heat exchanger is converted to two passes; for the same flow rate, the pressure drop per unit length in tube side will __________ times.
5. The centre to centre distance between two consecutive baffles in a shell and tube heat exchanger is called the baffle pitch or baffle spacing, which is more than 1/5th the I.D. of the shell. Which of the following is not a function of the baffles?
Options
A. To increase the residence time of shell side fluid.
B. To provide support to the tube bundle.
C. To reduce the induced vibration in the tubes.
D. To increase the tube side heat transfer co-efficient by inducing turbulence.
A. Rivetting provides a permanent fastening method.
B. The joint made by overlapping of one plate over the other, and then rivetting the two plates together with two rows of rivets is called 'double rivetted butt joint'.
C. Shank diameter of the rivets should be less than the size of the hole drilled in the plate for rivetting.
D. The efficiency of a rivetted joint is the ratio of the strength of the rivetted joint to the strength of the solid plate.
Correct Answer: The joint made by overlapping of one plate over the other, and then rivetting the two plates together with two rows of rivets is called 'double rivetted butt joint'.
9. In a shell and tube heat exchanger having triangular pitch, the shell side equivalent diameter is given by
10. A high vapour velocity is required for high plate efficiency in a seive plate coloumn. The satisfactory value of operating vapor velocity for design purpose in seive plate column is about __________ percent of the flooding velocity.