Heat Exchangers Review

Question 1

The heat flow from a tube to the attached fins would be by:

Answer 1

Conduction

Question 2

Baffles in shell and tube type heat exchangers are used for:

Answer 2

Preventing dead bypass areas

Question 3

Which baffles are normally used to change the shell side flow from parallel or counter flow into a mixed flow design?

Answer 3

Longitudinal baffles

Question 4

To ensure that no mixing of shell and tube side fluids can occur as a result of tube sheet leaks, what is used?

Answer 4

Double tube sheets are used

Question 5

The main function of a heat exchanger is to:

Answer 5

Reduce the temperature of one fluid, while increasing the temperature of the other

Question 6

Compared to the fixed welded tube sheet type heat exchanger, “U” tube bundles used in heat exchangers help reduce problems related to:

Answer 6

Differential expansion and contraction​

Cleaning the inside of the shell
​
Cleaning the outside of the tubes

Question 7

Compared to the split backing ring design, the major disadvantage of the pull through floating head design is:

Answer 7

Larger clearances exist between the shell and the tube bundle

Question 8

In a shell and tube heat exchanger, the most efficient heat exchange takes place with which design:

Answer 8

Counter flow

Question 9

Floating tube sheets are principally designed to:

Answer 9

Float Axially

Question 10

The shell side of a fixed tube sheet exchanger would be cleaned by:

Answer 10

Flushing

Question 11

If the front head (channel head) of a heat exchanger was divided into two by the use of a channel head baffle, the tube side would have #___ passes.

Answer 11

2

Question 12

Which baffle helps to reduce the eroding effect of the fluid in exchangers with high inlet velocities?

Answer 12

Impingement​

Question 13

When pulling a tube bundle from a multi-pass, shell and tube heat exchanger, what precautions should be observed?

Answer 13

Pull bundle using eye bolts​
Support bundles on baffles when lifting​
Ensure no toxic vapours are present

Question 14

When lifting a large tube bundle with baffles, where would you support?

Answer 14

Support the bundle under the baffles or tube sheet

Question 15

On a heat exchanger that has a floating head with a split-backing ring, what is bolted to the split-backing ring?

Answer 15

Floating head cover

Question 16

The most common type of tube joint is the:

Answer 16

Expanded

Question 17

All the fluids represented here are flowing in the same direction. The higher temperature Fluid 2 cannot be cooled:
(picture shows fluid 1 entering the top left, leaving bottom right, fluid 2 entering left leaving right side, parallel flow)
1
2===(=========)==2
1

Answer 17

Cannot be cooled below the highest temperature of Fluid 1

Question 18

Stress on a fixed tube sheet exchanger is sometimes reduced by the use of:

Answer 18

An expansion joint in the shell

Question 19

Photo shows;
Fluid entering top of shell/tube on left, longitudinal baffle horizontally, dividing into 2, fluid flows in, goes right, then down, then left and exit at bottom;
How many passes?

Answer 19

One pass

Question 20

The device used to prevent internal components from corroding due to electrical currents being produced by dissimilar metals is a (an):

Answer 20

Sacrificial zinc anode

Question 21

Which method is used first on a double tube sheet exchanger to determine which tube sheets are leaking?

Answer 21

Visual inspection of the tube sheet

Question 22

Routing the fluid through the inside of the tubes would be necessary if the fluid was:

Answer 22

High pressure

Question 23

A standardized exchanger size designation of 500 mm - 4000 mm would mean:

Answer 23

Shell diameter is 500 mm and tube length is 4000 mm

Question 24

A heat exchanger operates at 275 psi. What would be the recommended hydro test pressure?

Answer 24

412.5 psi

1.5x operating pressure

Question 25

As a safety precaution when removing the channel head for tube inspection, which set of studs should be loosened and removed first?

Answer 25

Bottom

let any liquids flow out first if any.