Cooling, Carbonation, and Blending Flashcards
Plate Heat Exchanger
Most common heat exchanger, series of plates, hot fluid in, cold fluid out
Shell and tube heat exchanger
Tubes (contained within the shell) rather than plates separate coolant from the hot liquid. Beer runs through tubes while coolant runs through the shell
Counter currant flow
Coolant flows opposite to the hot/warm beer, often the temp of the beer leaving HX is lower than the coolant entering it = risk of beer reaching its freezing point
Cocurrent flow
Useful when cooling beer a few degrees, eg when approaching the freezing point of beer. Beer will not be cooled to less than the temp of the coolant, ie will never freeze. Not as efficient, greater load on refrigeration
Double stage cooling
-Hot beer passes through zone 1, where coolant significantly lowers its temp
-Cooled beer passes through zone 2, where coolant adjusts the temp to desired value
-Greatly reduces risk of freezing beer in the HX
Carbonation: Temperature influence
CO2’s solubility in beer increases as the temperature decreases
Carbonation: Pressure influence
Henry’s law: CO2’s solubility in beer increases as the pressure increases
Carbonation: pH influence
CO2’s solubility in beer increases as pH increases
Carbonation: Gravity influence
As gravity increases (viscosity), CO2’s solubility in beer decreases
Maintaining carbontion
-Stable temperature
-Stable pressure
-Laminar, non-turbulent
DAW: Vacuum deaeration
Hot water sanitizes as its sprayed into a vacuum vessel, O2 & other dissolved gases escape easily
DAW: Gas stripping
Gas is injected into water until saturated; saturated water is sprayed into the vessel & gas escapes the droplets, also removing O2
DAW: Pack-bed gas stripping
Water is sprayed onto a packed bed which greatly increases water’s surface area, while N or CO2 flows upward, knocking O2 out of the water.
DAW: Membrane gaseous exchange
Water passes through a cartridge packed with hollow tubes made of hydrophobic material. Vacuum is applied to hydrophobic tubes, forcing gas into the tubes, but not the water because they’re hydrophobic.
