Dan Strömberg

Breweries

Glycol loop hints

§  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

Piping for the glycol system | 8/11/2015 | Dan Strömberg 2

The basic facts

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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.

Chiller

4 3 2 1

5 6 7 8

Simple design that don’t help to balance the system.

Actuated valves for supply Manual valves for return

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

Beer

Storage

Conditioning

6

7

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 (pre-insulated), 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

•  Carbon steel

•  Stainless steel •  COOL-FIT ABS

•  PE100

•  PEX

Pre-insulated piping •  COOL-FIT ABS Lite

•  COOL-FIT ABS Plus Maintenance free, energy efficient, easy to install

Only mechanical connections, hard to install straight, limited size range, more expansion contraction

Expensive, very desirable for thieves, insulation needed

Need to be painted to prevent corrosion, heavy, time consuming to install, insulation needed 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

No hard jacket, budget solution, only up to 6”

Daily problems in Chilled Water & glycol Applications with Metal Piping Systems - CORROSION

GMSM COOLING 13 ‹#› 13

Stainless Steel Carbon Steel Copper

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

‹#› 15

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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Try to get the connection on the cone mounted horizontally if possible No Yes

With this optimal configuration you only need:

2 reduced tees

4 tees

2 elbows

1 actuated valve

1 manual valve

6 transition unions.

Return

Supply

Front view Side view

Reduced Tees

Option 1

Try to get the connection on the cone mounted horizontally if possible No Yes

With this optimal configuration you only need:

2 Reduced tees

4 tees

2 elbows

1 actuated valve

4 manual valves

3 transition unions.

3 valve transition kits

Return

Supply

Front view Side view

Reduced Tees

Option 1:2

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Option 1:2

Try to get the connection on the cone mounted horizontally if possible No Yes

Return

Supply

No Front view Side view

Reduced Tees

Option 2

If your tank connections are in the same vertical line you have to use more fittings

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

Return

Supply

No Front view Side view

Reduced Tees

Option 3

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.

For this option you need:

2 reduced tees

4 tees

5 elbows

1 valve

1 actuated valve

6 transition fittings

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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)

Solenoid Actuated Ball valve

Manual ball valve

Manual ball valve

Green or Green-Yellow

Ground

Valv

e co

nnec

tions

White

Neutral Black or Red

Line/ hot

24V DC or 115V AC

From control panel

115V AC/DC

For T

ype

104

valv

e

3

2

1

E

For T

ype

107

valv

e

2

1

3

SPDT Relay

Single Pole Double Throw Relay configuration if you put in actuated valve instead of solenoid valve and controller only can handle solenoid valves

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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

Heat transfer fluid has to be diluted to the right concentration before charging. Do not use ethylene 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.

•  The minimum recommended concentration is 25%

glycol for most applications. Diluting the concentration below 25% to 30% glycol may reduce the inhibitor concentration to a level that may not provide adequate corrosion protection. Solutions of glycol less than 25% 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

Us high quality water or buy pre-mixed glycol. Do not combine fluids of different manufacturers!

•  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, and cause clogging of system components. To assure inhibitor effectiveness, the levels of chlorides and 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

You can ad a dye to the glycol to trace a leak easier. Do not use un-inhibited 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

•  Try to get the concentration correct to the desired 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).