Evaporation

Question 1

Multiple effect evaporation technology works on what principal regarding pressure and temperature of water?

Answer 1

Water boils at a lower temperature when pressure is reduced

Question 2

What evaporators are in the 1st effect?

Answer 2

Evaporators #1-4

Question 3

What evaporators are in the 2nd effect?

Answer 3

Evaporators #5-8

Question 4

Which effect evaporators operate under a higher vacuum pressure?

Answer 4

1st effect evaporators

Question 5

What are the two heating sources for the 1st effect evaporators?

Answer 5

MP steam & 200 proof ethanol vapors

Question 6

What is the one heating source required for the 2nd effect evaporators?

Answer 6

1st effect vapors

Question 7

List the three process streams created in the Evaporation System and its final use.

Answer 7

Syrup- Mixed with solids to form DDGS
Steam Condensate- Reused in Deaerator
Process Condensate- Used as cook water

Question 8

What is the main feed to the 1st effect evaporators?

Answer 8

Thin Stillage

Question 9

What is the name of the main product that feeds from the 1st effect evaporators to the 2nd effect evaporators?

Answer 9

Mid Stillage

Question 10

What percentage solids is the syrup that flows from Evaporator #8?

Answer 10

36-42%

Question 11

What is the purpose of the evaporators?

Answer 11

Vaporize water out of thin stillage feed stream

Question 12

What type of exchanger are the falling-film evaporators?

Answer 12

Shell and tube

Question 13

Where are the separator tanks located?

Answer 13

Directly below the falling-film evaporators

Question 14

In the falling-film evaporator, what part of the exchanger does the thin/mid stillage flow? Where does the heat source flow?

Answer 14

Thin/mid stillage flows down through tubes
Heat source flows through shell side

Question 15

What happens to the stillage as it encounters low pressure in the separator tank?

Answer 15

Water flashes out of the stillage

Question 16

Where does the majority of the stillage in the separator tank flow to?

Answer 16

Re-circulated back to the top of the evaporator

Question 17

What three vapors condense on the shell side of the falling-film evaporators? Which evaporators?

Answer 17

200 Proof- Evaporators #1/2
Steam condensate- Evaporators #2-4
Process condensate- Evaporators #5-8

Question 18

Which effect vapors produces the LP steam flowing in the Beer Column and Side Stripper as a heat source?

Answer 18

2nd effect

Question 19

What system requires the function of the Evaporation System to operate?

Answer 19

Distillation System

Question 20

What are the two main purposes of the Evaporator Pumps?

Answer 20

Re-circulate stillage from bottoms of evaporators to the tops
Pump a portion of stillage from the bottoms of evaporators to the next

Question 21

What are the two flows out of the Steam Condensate Receiver?

Answer 21

A portion of steam/condensate flashes into steam and flows to 1st effect vapor line. Remaining condensate flows to the Deaerator

Question 22

Why does condensate feed to the Steam Condensate Receiver flash into a vapor?

Answer 22

The Steam Condensate Receiver operates at a lower pressure than the pressure in the feed line

Question 23

What is the name of the condensate on the shell side of the 2nd effect evaporators? Where does it flow to?

Answer 23

Process condensate. Process Condensate Receiver

Question 24

What two places can the Process Condensate Receiver Pump flow to?

Answer 24

Cook Water Tank & Thin Stillage Tank

Question 25

What is the purpose of the Evaporator Process Condensate Filters?

Answer 25

Remove particulates in condensate to the Cook Water Pre-heater to prevent fouling in the exchanger

Question 26

What is the purpose of the Evaporator Drain Pump?

Answer 26

Drains evaporators for offline cleaning processes

Question 27

What two evaporators can the Syrup Draw Pump pull from?

Answer 27

Evaporator #7 & #8

Question 28

Why might we flow syrup to the Thin Stillage Tank?

Answer 28

Off-spec density (%Solids) of syrup

Question 29

During normal operation where does syrup from the Syrup Draw Pump flow to?

Answer 29

Syrup Tank

Question 30

Why is the Thin Stillage Tank essential for steady operation of the evaporators?

Answer 30

Thin Stillage Tank operates as a buffer for flow irregularities to the evaporators

Question 31

Which Evaporator receives the thin stillage feed stream from the Evaporator Feed Pump?

Answer 31

Evaporator #1

Question 32

What is the main purpose of syrup?

Answer 32

Increases protein content of DDG

Question 33

What five pieces of equipment receive syrup from the Dryer Syrup Pumps?

Answer 33

Centrifuge Conveyor #1 Centrifuge Conveyor #4 Dryer B Mixer Dryer D Mixer Wet Pad Conveyor #1