Month: March 2019

In a shell and tube heat exchanger for a given heat transfer surface area, smaller diameter tubes are favoured as compared to larger diameter ones; because the smaller diameter tubes ______________?

by
In a shell and tube heat exchanger for a given heat transfer surface area, smaller diameter tubes are favoured as compared to larger diameter ones; because the smaller diameter tubes ______________?

A. Are easier to clean
B. Are less prone to fouling
C. Can be fitted into a smaller shell diameter hence the cost of the heat exchanger would be less
D. None of these

In a vertical short tube evaporator (Calandria type), the ______________________?

by
In a vertical short tube evaporator (Calandria type), the ______________________?

A. Tube dia of 2.5-7.5 cms, tube length of 75-200 cms and cylindrical drum dia of 1-6 metres are
normally used
B. Area of central downtake is equal to 40 to 100% of total cross-sectional area of the
surrounding tube
C. Liquor is inside the tube while the steam is outside the tube
D. All A., B. & C.

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 ?

by
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 ?

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