Week 2 Flashcards
Examples of quarter-turn valves
Butterfly and ball
An example of a single seat valve and why you would use one
Divert valves:
Fully CIP’able, faster response time, more hygienic, automation
Why might you use Mix Proof valves?
-Can fully automate 24/7
-Can run cleaner through one and product through the other side at same time
4 goals of sanitary design (in valves)
Cleanable - can you run CIP through it?
Self- draining - product or liquid doesn’t remain in the valve after usage
Made of compatible materials - FDA/USDA compliant elastomers - can be digested if pieces come off in product
Construction materials must be full compatible with product, environment, cleaning materials and methods used and be inert, nonporus and nonabsorbent
Smooth and accessible surfaces - free of pits, cracks, corrosion, gaps, bolts, rivets, dead ends. Easily disassembled for inspection and cleaning
Cool things about Electropolish?
Can fill any cracks caused by hydropressing or cold pressing
Good wettability
Sluff off pollutions more easily
Easier to spot corrosion
Three functions of valves, regardless of design
Shut-off
Divert
Modulating (or throttling) control
What is a converging valve?
A divert valve that allows flow into one outlet from two different inlets (at a time)
Why would a reverse acting shut off valve be beneficial?
For dynamic closures
Reduces hydronic shock
Free-draining top-to-bottom flow
Benefits of running a matrix of valves?
Can run concurrent processes with separation
Run multiple, dissimilar products flow through each valve and require separation (concurrent filling, emptying and CIP cleaning ex)
What is an atmospheric gap in a valve?
Prevents cross contamination by venting liquid out if a seal fails
Bonus, it gives you a visual indicator of a failed seal by leaking
Advantages of a matrix over a flow panel?
Adv matrix:
PLC control
Probability of occurrence low
Product safety is not jeopardized
Record of activity
Neg of flow panel:
Uncertainty to “what” could happen
Probability of occurrence high
Consequences could be severe to product safety
No record of activity
What application might a constant pressure valve be utilized for?
A filler - to provide a steady flow and constant pressure
Name the 3 heat transfer mechanisms
Conduction
Convection
Radiation
What factors affect heat conduction through a surface?
Material type, thickness of wall, surface area and distance
Which are more effective at transferring heat: co-current or countercurrent in heat exchangers?
Why?
Countercurrent
Liquids come into “contact” at the most extreme differences in temp
What must be taken into consideration when using direct steam injection?
Do you have the capacity to handle extra product, concentration…(look this up)
Give 3 uses for heat exchangers in breweries
Cool wort
Mashing w/ heating jackets
Collandria
Tunnel pasteurization
HLT
Steam boiler
Why are plate heat exchangers so efficient?
Turbulent flow, plates close together, big surface area, capable of countercurrent flow, thin plates
What happens to aluminum in contact with caustic?
Forms Hydrogen gas (explosive!)
Define the term “wetting” in terms of a material’s surface
You want material to have well wetted properties which allows a surface to accept a cleaning solution and not “ball up” and only contact in a small patch
What are the two most common SS used in modern breweries?
304L and 316L
L are “low carbon” versions that have better resistance to corrosion
What is galvanic corrosion
Dissimilar materials in a conductive medium (like water)
Example wrench left onto the top of a fermenter (moisture in the air can act as the conductive medium)
What is general uniform corrosion?
Rust
Examples of erosion corrosion?
Abrasion (grain, etc), cavitation
What is intergranular corrosion?
Corrosion caused by repeated heating and cooling cycles - weld decay, heat affected
What causes pitting?
Loss of passivation on SS - damage of that thin protective layer (more)
Chlorine is one of the biggest causes, exasterbated by heat
What is contact corrosion?
Similar to galvanic, it’s a combination of multiple factors
Name the 9 types of corrosions
General uniform
Galvanic
Erosion
Intergranular - not common in breweries
Pitting
Crevice - between two joints, bad welds
Contact - sum of galvanic, pitting, and crevice
Microbiological induced
Stress corrosion cracking
What happens during passivation?
Removes “free iron” contamination left from the fabrication process and promotes the protective Chromium Oxide layer
Starts w/ caustic cleaning of oils & dirt
Then Acid wash (nitric or (better/safer) citric acid @ 4%)
45min (20-120min) @ 100F (60-160F) @ 4% citric acid solution (20-50% Nitric acid by volume)
Three types of welding?
And what is the most common in brewery construction?
Stick
MIG*
TIG
Name some locations of important elastomers in the brewhouse
Valve seats (internal seals)
Manway gaskets
Pump seals
Inter-fitting gaskets
Hose linings
Bottle line O-rings
Keg Fittings
Filter gaskets
What are some elastomer types and where they might be beneficial in the brewhouse
Buna / BunaN - widely used in food, dairy, beverage and sanitary. Limited use due to temp and chemical concerns <80C, good oil and solvent resistance. 2% caustic 0.5% acid, moderate resistance to aromatics.
EPDM - very resistant to steam, good resistance to mild acids, alkalis and alcohols, very abrasion resistant, good tensile strength - widely used in Europe , most likely best choice in brewery use
Neoprene - not common, has a smell that can be picked up
Silicone - rarely used, ok for cold applications if not running high % caustics or acids
Teflon - steam applications, if held flat, will deform otherwise. Good for valve stem seats, but poor ability to crest seal
Viton - good for 320-350F, but not for steam. Very acid resistant - in valve seats primarily
Why do we insulate? 6 things
Conserve energy by reducing heat loss or gain
Control surface temps for personal protection
Facilitate temp control of a process
Prevent water condensation in cold surfaces
Increase operating efficiency of HVAC and other systems
Prevent or reduce damage to equipment - also a bit of physical protection from accidents
What’s “R value”?
The thermal resistance “R”: the overall resistance of a system to the flow of heat. How well the insulation creates a barrier to the heat
Types of insulations (5)?
Fiberglass
Armaflex (used to cover glycol piping). Both of these will suck up water unless protected
Closed cell polyethylene
Styrofoam
Trimer
Name 7 materials used in brewing vessels
SS, copper, brass, aluminum, glass/epoxy lined, steel, wood
List 5 material properties that must be considered in brewing vessels and equipment
Temp resistance
Chemical resistance
Corrosion resistance
Ductable density - formability
Heat capacity
Heat transmission
Finish
Hardness
Clean ability (wettability)
What causes contact corrosion in SS?
Contact with a dissimilar metal (particularly anodic or least noble) in an electrically conductive liquid
Name 6 materials that may be transferred by piping in a brewery
Beer, steam, water, glycol, CO2, compressed air, refrigerant gas/non glycol
Why is it important to inspect gaskets on a routine basis?
For micro bacterial contamination, physical condition (broken, leaking, deformation)
Name two advantages and two disadvantages of Buna-N as a gasket seal material
2 adv: cheap, resistant to organic (oils, solvents), resistant to tearing and abrasion
2 diss: less resistant to PAA sanitizers, limited temp resistance
What are the three types of compressors?
Piston, worm (“screw”), turbo
What type of refrigeration is most commonly used in a brewery?
Compression chillers
List the components of a basic single-level compression refrigeration system?
Compressor
Evaporator
Condenser
Expansion valve (throttle)
What is the function of the compressor in a basic refrigeration system?
Increases pressure, increases temperature and acts as a flow mechanism
List the critical factors important for the efficient operation of a compression refrigeration system
Want evaporation temp to be high and condensation temp to be low. The delta Temp between them to be as close as possible for efficiency
What is the definition of a primary refrigerant?
It is the refrigerant that is circulating and doing the cooling. By changing its state, heat will be absorbed (evaporation) or released (condensation).
Why are secondary refrigeration systems often used in breweries?
People safety, food safety - don’t want to cross contaminate
List 3 secondary refrigerants
Glycol, water, brine
Why is ammonia a commonly used primary refrigerant?
It’s effective, thermodynamics are excellent, pretty cheap, phase change is close, has a smell and it’s been around and used for a very long time - it’s well known 1874
List 3 general classes of refrigeration compressors
Piston, worm (“screw”), turbo
List 4 advantages of centralized refrigeration plants
Common condensers, common equipment, spare parts (lower inventory, training), you can have a cooling reserve, energy demands spread across the entire brewery. You can take out a single condenser for maintenance and the system still can work. If you are using ammonia, it’s not spread out everywhere
List 4 disadvantages of de-centralized refrigeration plants
Spare parts, need a back up for every system in case it goes down, more expensive, electrical demand
Advantages: shorter lines, temp control more precise
Instead of a compressor, what is the driving mechanism for an adsorption refrigeration plant?
It’s thermal drive - done through chemical nature vs mechanical means
Select objectives when selecting valves (4)
Low cost
Good longevity
Desired service characteristics
Compatibility w/ controlled fluids
What is a Cv value?
Cv is the flow coefficient.
It’s defined as the flow rate through a valve as a ratio of the corresponding pressure drop across it
Higher Cv = lower pressure drops
What is the Cv value used for?
It’s used to define the flow characteristics of a valve throughout its range, from fully open to full closed.
The engineer must match the value to an actuator and the fluid system requirements
Define the term controller
The device which establishes set point and differentiates set point value from feedback value to produce a control response
What is a gas compressor?
A mechanical device that increases the pressure of a gas by reducing its volume
Why must compressed gas (air) be dried?
Because it will release moisture once pressure is released otherwise. This moisture can cause corrosion at pneumatic actuating drives
List 4 uses of CO2 related to brewing
Carbonation of beverages
High pressure extraction
Inert gas packaging - fillers
Neutralization if alkaline effluents
What are the tasks of a CO2 recovery plant?
Eliminate undesirable ingredients from the fermentation CO2 (cleaning)
Storage of the cleaned, compressed CO2 gas
What substances are commonly contained in recovered CO2 from a fermenter?
Ethyl alcohol
Hydrogen sulfide
Dimethyl sulfide
Acetone
Oxygen
List steps in CO2 recovery and storage in a brewery
Foam trap - removed any foam
Gas re-direction station - to outside
Gas balloon - acts as buffer
Gas washer - w/ O2 free water
CO2 compressor -
CO2 pre-filter -
CO2 dryer
CO2 active carbon filter
CO2 trap filter
CO2 condenser
CO2 stripper
CO2 storage as liquid
What’s bad about oversized steam pipes?
What’s bad about undersizing steam pipes?
Neg Over:
greater cost
Greater heat loss
Great volume of condensate formed
Neg Under:
Lower pressure to steam users, or
Not enough volume of steam
Water hammer and erosiom
Name 3 types of pressure reducing valves
Direct acting pressure reducing valve
Pilot operated reducing valve
Pneumatic or electric pressure reducing valve
Name 3 basic types of steam traps
Mechanical/density
Thermostatic
Kinetic Energy
Name 3 main phases of a brewery construction project
Feasibility and pre-study
Pre- project
Engineering
How much water is used to wash a bottle in a bottle washer?
Min 150-200ml/bottle regardless of size
