A huge number of technological processes in the food industry are tied to cooling. This is required by the dairy and meat industries, winemaking, beer and soft drinks manufacturing industries, oil and fat and confectionery industries, as well as many other industries.
A heat carrier, antifreeze (more general terms) or coolant (a name closer to the functionality) for a food enterprise must perform its main task - to transfer cold or heat between different parts of the heat exchange circuit. In addition, the heat carrier must not harm the circuit, primarily due to corrosive effects on metals. Also, taking into account the scope of application, the issue of the absence of harmful effects on the environment, which consists of personnel and the food products themselves, must be resolved.
First, let's determine the temperature range in which the heat carrier should operate.
The lower temperature limit is the lowest temperature to which the heat carrier can be cooled. Here it is necessary to consider 2 factors – the temperature given by the refrigeration equipment and the temperature of the environment in which the circuit itself is located. If the circuit is completely or partially located outdoors, the external temperatures in winter may be lower than those given by the refrigeration machine. The freezing point of the heat carrier (coolant) should be selected in accordance with the lower of the two temperatures.
Since the requirements for the temperature minimum can vary greatly, attention should be paid to the appropriate base of the heat carrier. Well-known and long-known glycol heat carriers/coolants are acceptable for use up to -400 C. Already at temperatures below -35℃, they become very viscous, which complicates their pumping, and accordingly heat transfer. If the project still requires temperatures below -40℃, it is necessary to consider coolants on a different basis, for example, based on potassium formate. They are able to operate up to -60℃, but are more demanding on operating conditions.
The upper temperature limit is the highest temperature possible in the circuit. For cooling systems, it is usually low. Glycol-based coolants can operate normally until they start to boil, that is, up to +100℃, so in this case this parameter is not a limitation. When it comes to antifreezes based on potassium formate, there is a strict ban on heating the coolant more than +40℃.
Are corrosion inhibitors needed in coolants for the food industry?
Of course, ferrous and non-ferrous metals in the circuit need anti-corrosion protection. However, in cases where the system is completely (including heat exchangers) constructed of food-grade stainless steel, the consumer may decide to do without corrosion inhibitors in the coolant.
The issue of coolant safety is of paramount importance for the food industry. Despite the fact that the coolant circulates in the technical system and in no case should it get into the cooled food product, accidents of circuit leakage cannot be avoided. “External” contact with the coolant should not be harmful to people. The absence of toxicity is a characteristic property of heat transfer fluids/coolants based on propylene glycol and potassium formate.
To summarize: the choice of coolant for food production requires certain qualifications and time.
Contact our company, and experienced specialists will help you make the right choice from a wide range of coolants produced by Stron LLC.
