Evaporation Flashcards
Multiple effect evaporation technology works on what principal regarding pressure and temperature of water?
Water boils at a lower temperature when pressure is reduced
What evaporators are in the 1st effect?
Evaporators #1-4
What evaporators are in the 2nd effect?
Evaporators #5-8
Which effect evaporators operate under a higher vacuum pressure?
1st effect evaporators
What are the two heating sources for the 1st effect evaporators?
MP steam & 200 proof ethanol vapors
What is the one heating source required for the 2nd effect evaporators?
1st effect vapors
List the three process streams created in the Evaporation System and its final use.
Syrup- Mixed with solids to form DDGS
Steam Condensate- Reused in Deaerator
Process Condensate- Used as cook water
What is the main feed to the 1st effect evaporators?
Thin Stillage
What is the name of the main product that feeds from the 1st effect evaporators to the 2nd effect evaporators?
Mid Stillage
What percentage solids is the syrup that flows from Evaporator #8?
36-42%
What is the purpose of the evaporators?
Vaporize water out of thin stillage feed stream
What type of exchanger are the falling-film evaporators?
Shell and tube
Where are the separator tanks located?
Directly below the falling-film evaporators
In the falling-film evaporator, what part of the exchanger does the thin/mid stillage flow? Where does the heat source flow?
Thin/mid stillage flows down through tubes
Heat source flows through shell side
What happens to the stillage as it encounters low pressure in the separator tank?
Water flashes out of the stillage
Where does the majority of the stillage in the separator tank flow to?
Re-circulated back to the top of the evaporator
What three vapors condense on the shell side of the falling-film evaporators? Which evaporators?
200 Proof- Evaporators #1/2
Steam condensate- Evaporators #2-4
Process condensate- Evaporators #5-8
Which effect vapors produces the LP steam flowing in the Beer Column and Side Stripper as a heat source?
2nd effect
What system requires the function of the Evaporation System to operate?
Distillation System
What are the two main purposes of the Evaporator Pumps?
Re-circulate stillage from bottoms of evaporators to the tops
Pump a portion of stillage from the bottoms of evaporators to the next
What are the two flows out of the Steam Condensate Receiver?
A portion of steam/condensate flashes into steam and flows to 1st effect vapor line. Remaining condensate flows to the Deaerator
Why does condensate feed to the Steam Condensate Receiver flash into a vapor?
The Steam Condensate Receiver operates at a lower pressure than the pressure in the feed line
What is the name of the condensate on the shell side of the 2nd effect evaporators? Where does it flow to?
Process condensate. Process Condensate Receiver
What two places can the Process Condensate Receiver Pump flow to?
Cook Water Tank & Thin Stillage Tank
What is the purpose of the Evaporator Process Condensate Filters?
Remove particulates in condensate to the Cook Water Pre-heater to prevent fouling in the exchanger
What is the purpose of the Evaporator Drain Pump?
Drains evaporators for offline cleaning processes
What two evaporators can the Syrup Draw Pump pull from?
Evaporator #7 & #8
Why might we flow syrup to the Thin Stillage Tank?
Off-spec density (%Solids) of syrup
During normal operation where does syrup from the Syrup Draw Pump flow to?
Syrup Tank
Why is the Thin Stillage Tank essential for steady operation of the evaporators?
Thin Stillage Tank operates as a buffer for flow irregularities to the evaporators
Which Evaporator receives the thin stillage feed stream from the Evaporator Feed Pump?
Evaporator #1
What is the main purpose of syrup?
Increases protein content of DDG
What five pieces of equipment receive syrup from the Dryer Syrup Pumps?
Centrifuge Conveyor #1
Centrifuge Conveyor #4
Dryer B Mixer
Dryer D Mixer
Wet Pad Conveyor #1
