Chapter 15

Question 1

What is the section of the tower located above the feed tray called?

Answer 1

Rectifying or Enriching Section

Question 2

What is the section of the tower located directly below the feed tray called?

Answer 2

Stripping Section

Question 3

Describe how the liquid and vapor products on each tray in a tower could run countercurrent to each other

Answer 3

Vapor moving up the column while liquid moves down column

Question 4

After the level builds up on a tray, it flows over the weir. Where does the liquid go when it flows over the weir?

Answer 4

To the tray below it

Question 5

What kind of energy do molecules in motion have?

Answer 5

Kinetic Energy

Question 6

What is the condensed gas taken from a distillation column called?

Answer 6

Overhead product

Question 7

What is the bottoms product on a distillation column?

Answer 7

Residue, or the heavier components of the process

Question 8

What is the term for the temperature at which liquid turns to gas?

Answer 8

Boiling Point

Question 9

What two components does a distillation column balance?

Answer 9

Heat and Material

Question 10

What is the incomplete separation of a chemical in a distillation column called?

Answer 10

Overlap

Question 11

What is the condensed product that is pumped back to the top of a tray of a distillation column called?

Answer 11

Reflux

Question 12

What device is designed to maintain the heat in a column?

Answer 12

Reboiler

Question 13

Name three types of trays found in a distillation plate column.

Answer 13

Bubble cap
Sieve
Valve

Question 14

What is heat that cannot be measured called?

Answer 14

Latent Heat

Question 15

Name two types of distillation columns.

Answer 15

Packed and Plate

Question 16

List four conditions that can affect temperature in a distillation colum.

Answer 16

Pressure
Flow Rates
Fluid Levels
Feed Composition
Reflux Rate
Equipment Problems

Question 17

Name three types of packing used in a distillation column.

Answer 17

Berl saddle
Intalox saddle
Rasching ring
Cross-partition ring
Flexring
Sprial ring
Mini-ring
Sulzer packing

Question 18

How do you break a flood in a distillation column?

Answer 18

Decrease the feed rate, reflux rate, or bottom temperature

Question 19

Define temperature gradient

Answer 19

Progressively rising temperatures from the bottom of a distillation column to the top

Question 20

Downspouts that allow liquid to drop down to lower trays in a column

Answer 20

Downcomer

Question 21

The balance of the products (vapor and liquid) returned to the column from the kettle reboiler.

Answer 21

Boil-up Rate

Question 22

Occurs when the vapor velocity is so high that liquid down flow in the tower is restricted. Liquid accumulates in the tower, differential pressure increases, and product separation is reduced.

Answer 22

Jet Flooding

Question 23

Separation of two or more components through distillation.

Answer 23

Fractional Distillation

Question 24

Excessive liquid flowing down a column blocks vapor flow up the column in one section.

Answer 24

Local Flooding

Question 25

Operating a column at maximum conditions.

Answer 25

Overloading

Question 26

The characteristics associated with a liquid’s tendency to change state or ­vaporize inside a distillation system.

Answer 26

Relative Volatility

Question 27

4 most common types of packing

Answer 27

Rasching Ring
Berl Saddle
Intalox Saddle
Metal Pall Ring