Breweries Glycol loop hints

Breweries
Glycol loop hints
Dan Strömberg
The basic facts
§  Your inhibited propylene glycol media’s main task is to remove heat
from you fermentation tanks, brite tanks, cold liquor tanks, worth
chiller and also in some installations your walk in cooler
§  Normal temperature range for the media are 20F to 28F. (the bigger
ΔT the easier the exchange)
§  Media pressure 15 to 60 psi
§  Recommended velocity below 5 ft/s (without variable speed pumps)
to 7.5 ft /s (with variable speed pumps) ASHRAE 90.1-2010
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Piping for the glycol system | 8/11/2015 | Dan Strömberg
What size pipe to use?
•  To size the pipe right you need to know how much flow of glycol that will be needed.
•  This is determined by the fermenters. Normally your tank manufacturer can tell you
the needed flow/jacket for your fermenters and the bright tanks.
•  You then add up all the flow for all tanks and your now have a total.
•  Now you need to ask yourself how many of the tanks/ jackets will be calling for flow
at the same time? (for example maybe only 60% is calling for cooling at the same
time) This will get you an actual need.
•  It is also very wise to calculate and add for future expansion so that you don’t have
to change out your piping when you expand later on.
•  With the total needed flow we can now help you and pick the right pipe size. The
golden rule is (and this is even an ASHRAE standard) to keep the velocity in the
pipe to 5 ft/s or less and if you have variable speed pumps you can go up to 7.5 ft/
s.
Higher velocity = higher pressure drop (in fact if your velocity doubles your pressure
drop quadruples) and noise and water hammer effect also increases.
For example if you increase the velocity with 50% from 5 ft/s to 7.5 ft/s your pressure
drop increases with 225% and now your pumps need work harder (or you need
bigger pumps) and consume more energy.
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Manual valves for return
4
3
Actuated valves for supply
2
1
Chiller
5
6
7
Simple design that don’t help to
balance the system.
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Valve to bleed over
from supply to return, to
make sure you never
dead head a pump if all
fermentation valves are
closed
Chiller
4
3
2
1
5
6
7
8
First in last out
In this layout tank number one have the shortest supply
piping but the longest return piping. Tank number 8 will
have the longest supply piping but a the shortest return
piping. You get a very balanced system with this layout.
Fermentation
Conditioning
Storage
Beer
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First in last out
•  Place header higher than tank
connections so that you don’t create air
locks.
•  Also place header high enough for future
taller tanks.
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Valves directly at header
Makes it easy to change to bigger and taller tanks in the future
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Example of and Close up look at the
end of the loop design.
Air release
valves
Bleed
valve
Tank return valve
Tank supply valve
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Piping
•  Use piping material that can handle the media and also the media
temperature. Example on suitable piping materials: COOL-FIT ABS Plus (preinsulated), COOL-FIT ABS Lite (pre-insulated), COOL-FIT ABS, ecoFIT
(PE100), iFIT (multi layer pipe), PEX, Copper, Stainless Steel schedule 10 and
Carbon steel schedule 40
•  PVC and CPVC can not be used because the lowest temperature limit for PVC
and CPVC is 32F (some manufactures set the limit to 40F) and you normally
run your glycol below 32F also its limited chemical resistance to propylene
glycol is a big problem.
•  Make sure your piping is properly insulated and preferable with a jacketed
insulation (for wash-downs). Every time you see piping or equipment ice up or
condensate you loose money and It is also a source for mold. Pre-insulated
piping give you the highest quality and the most energy efficient solution, it is
also easy to install.
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Don’t flush money
down the drain
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Example of suitable piping material
•  Copper
Expensive, very desirable for thieves, insulation needed
•  Carbon steel
Need to be painted to prevent corrosion, heavy, time
consuming to install, insulation needed
•  Stainless steel
•  COOL-FIT ABS
•  PE100
•  PEX
Pre-insulated piping
•  COOL-FIT ABS Lite
•  COOL-FIT ABS Plus
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Time consuming, needs experienced installer,
insulation needed
Solvent cemented, quick install, low cost, insulation
needed
Welded, low cost, more expansion and contraction than
other plastics
Only mechanical connections, hard to install straight,
limited size range, more expansion contraction
No hard jacket, budget solution, only up to 6”
Maintenance free, energy efficient, easy to install
Daily problems in Chilled Water &
glycol Applications with Metal Piping Systems
- CORROSION
Stainless Steel
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‹#›
Carbon Steel
Copper
GMSM COOLING
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Daily problems in Chilled Water glycol
Applications with Metal Piping Systems
- Incrustations
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‹#›
Daily problems in Chilled Water glycol
Applications with Metal Piping Systems
- Condensation
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‹#›
Daily problems in Chilled Water glycol
Applications with Metal Piping Systems
– Insulation Damaged
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‹#›
Daily problems in Chilled Water glycol
Applications with Metal Piping Systems
– Mold
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‹#›
Daily problems in Chilled Water glycol
Applications with Metal Piping Systems
– Jackets Damaged
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‹#›
Return
Reduced Tees
Supply
With this optimal
configuration you
only need:
Front view
2 reduced tees
4 tees
2 elbows
1 actuated valve
1 manual valve
6 transition unions.
Try to get the
connection on the
cone mounted
horizontally if
possible
No
Yes
Option 1
Side view
Return
Reduced Tees
Supply
With this optimal
configuration you
only need:
Front view
2 Reduced tees
4 tees
2 elbows
1 actuated valve
4 manual valves
3 transition unions.
3 valve transition kits
Try to get the
connection on the
cone mounted
horizontally if
possible
No
Yes
Option 1:2
Side view
Option 1:2
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Return
Reduced Tees
Supply
If your tank connections are
in the same vertical line you
have to use more fittings
No Front view
For this option you need:
2 reduced tees
4 tees
8 elbows
1 valve
1 actuated valve
6 transition fittings
Try to get the
connection on the
cone mounted
horizontally if
possible
No
Yes
Option 2
Side view
Return
Reduced Tees
Supply
If your tank connections are
in the same vertical line you
have to use more fittings. This
is the same as Option 3 but
here the supply line is line up
with the connections and
don’t need any extra elbows.
No Front view
For this option you need:
2 reduced tees
4 tees
5 elbows
1 valve
1 actuated valve
6 transition fittings
Try to get the
connection on the
cone mounted
horizontally if
possible
No
Yes
Option 3
Side view
Option 3
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Tank valves
We recommend actuated ball valves (electric or pneumatic) for the supply
lines to the tanks because:
•  No need for a manual valve before and after the actuated valve as you
need with solenoid valves
•  They have manual override
•  Bigger bore = less pressure drop (to replace an 1”actuated ball valve you
need minimum a 2” solenoid valve)
•  No servo channels or tiny orifices that can clog and affect the function of
the valve
•  Make sure you get a housing fully in plastic= no corrosion, much less
condensation & that it is Nema 4x
•  Less water hammer (5-10 s from fully opened to closed for electric and
possibility to adjust time for pneumatic)
Manual ball
valve
Solenoid
Manual ball
valve
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Actuated Ball valve
2
For Type 107 valve
1
3
E
1
Valve connections
2
3
For Type 104 valve
SPDT
Relay
24V DC or 115V AC
Black or Red
White
Line/ hot
Neutral
Green or
Green-Yellow
Ground
115V AC/DC
From control panel
Single Pole Double Throw Relay configuration if you put in actuated valve instead
of solenoid valve and controller only can handle solenoid valves
Connections on tanks can be a huge
problem
If connections are not square or on the same plumb line piping could be an issue
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Air locks
Air will not travel down! If you get an air lock you will
not get desired flow and of course not the desired
cooling
A kink on a hose is course also a problem
Glycol return
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Air locks
Header goes up to higher elevation and later on down to a lower elevation but
no air vent valves so you can’t get the air out and you get an air lock.
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Notes for pressure testing
•  Double check that everything is installed according to drawings
and that supply piping is connected to supply on tanks (lower port
on jacket) and other equipment and return piping to return on tanks
(higher port on jackets) and other equipment.
•  Check ratings on tank jackets and other equipment's (for example
pump seals) and make sure to isolate if test pressure is higher
than pressure rating on jackets and equipment
•  Fill from bottom up and make sure all vent valves are open
•  Do hydronic testing 1.5 times higher than system pressure
•  This is also a good time to rinse the system
•  After pressure testing and rinsing make sure to drain the system as
much as possible so you don’t compromise your glycol mixture and
quality when you fill it again.
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Glycol
•  Always use propylene glycol and not ethylene glycol (that
is very toxic)
•  The fluid must be industrially inhibited propylene glycol.
The fluid contains corrosion inhibitors that are specially
formulated for systems to keep pipes and equipment free
of corrosion without fouling.
Heat transfer fluid has to be •  The minimum recommended concentration is 25%
diluted to the right
glycol for most applications. Diluting the concentration
concentration before
below 25% to 30% glycol may reduce the inhibitor
charging.
concentration to a level that may not provide adequate
Do not use ethylene
corrosion protection. Solutions of glycol less than 25%
glycol!
may be at risk for bacterial contamination. The maximum
recommended concentration of glycol is 60% for efficient
heat transfer.
•  New metal piping systems are typically coated with oil,
grease or a protective film during fabrication, storage, or
construction. Dirt, solder flux, and welding and pipe scale
can also cause problems. Therefore, thorough cleaning
of new systems is recommended.
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Glycol
•  Use only good quality water in solution with the
propylene glycol fluid. Water used to dilute propylene
glycol must meet certain minimum standards for
purity. Impurities in dilution water can increase metal
corrosion, aggravate pitting of cast iron and steel,
reduce the effectiveness of corrosion inhibitors,
increase inhibitor depletion rate, cause formation of
scale and other deposits on heat transfer surfaces,
Us high quality water or buy
and cause clogging of system components. To assure
pre-mixed glycol.
inhibitor effectiveness, the levels of chlorides and
Do not combine fluids of
different manufacturers!
sulfates in water used to dilute propylene glycols fluids
should be less than 25 ppm each and less than 50
ppm of hard water ions (Ca++, Mg++) (get a water
specification from your glycol supplier).
•  Distilled or deionized water is recommended. If good
quality water is unavailable, purchase pre-diluted
solutions of industrially inhibited propylene glycol fluid
from the fluid manufacturer or, if available, from the
distributor.
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Glycol
•  Mix the water and propylene glycol properly before you
fill your system. If that is not done you first introduce the
water and after that the propylene glycol but you then
need to circulate for at least 24 hours to ensure complete
mixing.
•  Check the liquid concentration with a refractometer or
other method to assure that the correct mixture is
obtained
You can ad a dye to the
glycol to trace a leak easier.
•  Try to get the concentration correct to the desired
Do not use un-inhibited
glycol!
percentage and don’t use to much glycol because every
extra percentage of glycol reduce the heat transfer rate
of the fluid and your fluid also get more viscous (thicker)
and harder to pump (more pump power and energy
needed)
•  If the system contains more than 250 gallons of fluid,
annual analysis should be done (normally provided free
of charge by the fluid manufacturer).
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