DOWTHERM™ SR-1

HEAT TRANSFER FLUID

Food & Beverage Processing Page 1

Chilling & Freezing
DOWFROST™ Inhibited Glycol-based Heat Transfer Fluid offers advantages in a variety of chilling/freezing and defrosting/dehumidifying applications. Breweries, wineries, dairies and fruit processors use DOWFROST™ to cool products during processing. They are also used by restaurants, bars, and in vending machines to cool liquid beverages.

The ingredients in DOWFROST™ are considered safe by the U.S. FDA food additive regulations1 for use in applications where incidental contact with food products or potable water is possible, including immersion freezing of wrapped meat, poultry, fish, seafood, vegetables, and fruit or winterization of RV plumbing systems. Both fluids are low in toxicity and odor, and virtually tasteless — important benefits in any food application.

Defrosting/Dehumidifying
DOWTHERM™ SR-1 is sprayed on refrigeration coils in walk-in freezers and cold rooms to remove condensation and maintain optimum chilling efficiency. Glycols mix with condensation from the coils, lowering the freeze point of the water to prevent frost formation. These sprayed fluids can also remove moisture from the air to control humidity.

DOWTHERM™ SR-1 may not be acceptable in some food applications. Contact your Dow representative for additional information, or contact us at Chemical.net.

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Philadelphia, PA 19136 USA
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DOWFROST™, DOWTHERM™ SR-1

Inhibited glycol-based heat transfer fluids for Applications

Applications and advantages of inhibited glycol fluids in the food industry

Inhibited glycol heat transfer fluids are widely used in the food industry for chilling and freezing food and beverage products. These applications include immersion freezing, cooling liquid foods and fermentation cooling. Inhibited glycols are also used to defrost equipment and dehumidify facilities, with specific applications including refrigeration coil defrosting and humidity control in meat packing operations.

Dow heat transfer fluids offer particular utility in food industry applications: DOWFROST* inhibited propylene glycol-based fluid, and DOWTHERM* SR-1 inhibited ethylene glycol-based fluid. The following information details the advantages of glycol-based heat transfer fluids, describes the physical and performance properties of DOW inhibited glycol fluids, and highlights some of their many food industry applications.

Why inhibited glycols are the preferred heat transfer fluids in the food industry

Inhibited glycol fluids have successfully demonstrated their ability to upgrade process efficiency, extend equipment life, and improve over-all economy while contributing to greater system cleanliness and safety. The following characteristics explain the preference glycols have gained in the food industry.

	The acute oral toxicity of propylene glycol is very low, similar to glycerin. Ethylene glycol is of moderate acute oral toxicity.
	Glycols provide good heat transfer ability and freeze protection with low volatility.
	Properly formulated with inhibitors, glycol fluids combat costly corrosion in heat transfer systems.
	Glycols are practically odorless and colorless, although they are sometimes dyed for easy detection of system leaks.
	Glycol/water solutions (up to 80 percent glycol) are not considered flammable; they have no flash points when tested under the Tag closed cup method.

*Trademark of The Dow Chemical Company

Inhibited glycol fluids are the answer to important food industry heat transfer needs

DOWFROST™and DOWTHERM™ SR-1 fluids offer specific advantages in a variety of chilling/freezing and defrosting/dehumidifying applications. These advantages include: The low oral toxicity of DOWFROST™ inhibited propylene glycol-based fluids (DOWTHERM™ SR-1 inhibited ethylene glycol-based fluid has moderate oral toxicity). The virtual absence of fluid odor or taste. Low corrosivity. Easy fluid analysis and reinhibition. Fast freezing performance. Dependable temperature control. Low flammability. No autoignition hazard. Easy regeneration and reconcentration. And, easy system maintenance and operation. These advantages can translate into significant productivity gains and cost savings as the following applications illustrate.

Chilling/Freezing

Cooling Liquid Foods

DOWFROST™ inhibited propylene glycol-based fluid is used extensively by breweries, wineries, dairies and fruit (juice) processors to cool liquid foods during processing. In addition, they are used by restaurants and bars, as well as in vending machines, to cool liquid beverages as they are dispensed.

In beverage processing, a 30 to 45 percent solution of DOWFROST™ fluid is circulated through cooling coils which may be submerged within a tank, or wrapped around it. The fluid provides dependable temperature control and lower temperature capabilities than water, so liquids can be chilled to 33˚F (1°C) or lower. In dairy can be bottled faster. DOWFROST™ fluid is nonflammable in solution.

Fermentation Cooling

DOWFROST™ fluid is also used by breweries and wineries to cool fermentation and wort tanks, and for refrigeration of yeast bulk storage tanks. A 30 to 45 percent solution of DOWFROST™ fluid is chilled in a primary refrigeration unit. The chilled fluid is then circulated through coils submerged in—or wrapped around—the tank.

DOWFROST™ fluid is low in toxicity and odor, and are virtually tasteless—important benefits since accidental contact with beverage products can occur in cooling operations¹. DOWFROST™ fluid will not affect the foaming or fermenting properties of beer or wine. And, the low temperature capabilities of DOWFROST™ fluid permits recovery of CO₂ generated during fermentation. This CO₂ can then be used later in the bottling process.

¹Propylene glycol is regulated by the U.S. Food, Drug and Cosmetic Act. It meets the requirements of the Food Chemicals Codex (FCC) and can be used for direct, as well as indirect, food contact applications. Appropriate regulations should be consulted for full details on the levels permitted in specific food types.

Considered chemically acceptable by the USDA and complying with U.S. FDA food additive regulations², DOWFROST™ fluid is commonly used for immersion freezing by processors of wrapped meat, poultry, fish, seafood, vegetables, and fruit. Immersion freezing owes its popularity among food processors to its speed and efficiency. Plus, it provides uniform freezing, a particular challenge with irregularly shaped foods. DOWFROST™ fluid provides faster freezing of foods than air or plate freezing, so production rates are increased. The speed with which products are cooled also reduces surface bacteria counts. And frozen product appearance and shelf life are improved.

Immersion Freezing of Wrapped Foods

In a typical immersion freezing process, food is tightly wrapped and sealed in air- and water-tight bags. It is then immersed in a freezing bath [12°F (-11˚C)] of 40 to 50 percent DOWFROST™ fluid in solution with water. In some cases, the wrapped foods are carried on a conveyor through freezing equipment where they are sprayed with a solution of cold DOWFROST™fluid. Food is bathed or sprayed until the proper depth of freeze is achieved, usually 3/8" to 1/2" (10mm to 13mm). Then the food packages are rinsed with water to remove excess glycol and are transported to a freezing room.

Packaging Carbonated Beverages

Sparkling wines, champagne, beer and other carbonated beverages are chilled prior to bottling to prevent loss of carbonation. For some beverages, cold DOWFROST is pumped through coils submerged in—or wrapped around—a process tank. In champagne production, inverted bottles of aged champagne are dipped in a chilled bath of DOWFROST™, freezing the contents in the neck of the bottle. This traps sediment for removal. Consistent product chilling is achieved because system equipment is easy to operate and fluids are easy to maintain and adjust.

Plastic Bottle Blow Molding

DOWFROST™is widely used by large dairies, other food processors and packaging companies to cool molds used to blow mold plastic bottles. A 30 to 45 percent solution of DOWFROST™ fluid is circulated through the mold for rapid cooling. Because these fluids remain liquid at lower temperatures than plain water, they cool molds faster, increasing production. Faster cooling also allows “flash” to be trimmed more quickly and cleanly, improving product quality.

Ice Making

Ice production plants use DOWFROST™ to freeze water quickly. Steel trays of water are lowered into tanks filled with a refrigerated and agitated 40 to 50 percent solution of DOWFROST™.