New Materials Ice at Every Temperature: Discover the Many Uses of PCMs
With the frozen food market becoming popular with the working urban middle class population, manufacturers cannot afford losses due to challenges such as constant power failures, especially in a country such as India. Adapting to solutions such as Phase Change Materials, a company can not only maintain temperatures in the event of power outage or unavailability, but also ensure complete customer satisfaction.
Imagine a hot sultry summer day, where the only respite comes from a mouth-watering, deliciously cold ice cream and the vendor you purchase it from gives you a morose looking half melted one instead. If he is an Indian vendor, 80 per cent of the time the reason for that unfortunate looking ice cream would be power failure.
Agreeing Vice President – Procurements, Western Refrigeration, Mohit Goel affirms, “In India, many cities and rural areas have frequent and continuous power failures. This results in melting of frozen products such as ice cream and affects the product quality and subsequent demand. This also results in a lot of wastage, if such products melt up to a certain level. With conventional eutectic solutions, which use sensible energy, there are two challenges - the hold over time per volume of the solution is less, which makes the overall weight of the machine very heavy; secondly, during the backup period the temperature band is quite wide. For example, the temperature range maintained is -33°C to -18°C while the temperature required is only -20°C to -18°C.”
Western Refrigeration is a company that is engaged in manufacturing of commercial refrigeration equipment, for example, visicoolers, freezers, chest coolers etc., and is one of the largest suppliers of these products in India and also export the same to many countries. With their clientele including all the major beverage, milk, dairy products and chocolate manufacturers in India, the company cannot afford to generate losses due to issues such as power failures.
The Philosophy Behind PCMs
In order to combat problems such as the one stated above, the company decided to use Phase Change Materials (PCMs) from Pluss Polymers. PCMs are special thermal energy storage materials being extensively used as a reliable source of energy to maintain required temperatures in various industries. It stores and release energy in the form of latent heat. The thermal energy transfer occurs when a material changes from a solid to a liquid or from a liquid to a solid.
This is called a change in state or ‘phase’. Elucidating the same with the aid of an example, Director, Pluss Polymers, Samit Jain says, “A most generic example would be ice. Ice as made from pure water provides a very good illustration of what phase change materials are. In its solid phase, water exists as ‘ice’ at sub-zero temperatures. When exposed to heat, the temperature of ice starts rising in correlation to its specific heat capacity, until at 0°C, it starts liquefying.” This is the phase change temperature for ice, and two very important observations are noteworthy during its phase change - the temperature remains constantly at 0°C for a long time and the latent heat capacity.
“The temperature remaining constant is regardless of the variation in the temperature outside. The ice cubes continue absorbing the heat; however, till all of the ice converts into water, the temperature is constant. With respect to the latent heat capacity, the energy absorbed at 0°C by ice to turn liquid is higher than energy absorbed at any other temperature. The jargon heat capacity, because the energy absorbed by ice remains ‘latent’ or ‘hidden’ and does not show as temperature change in the ice temperature,” he adds. As a result, if the requirement for a given application is to maintain temperatures invariably at 0°C, ice can be an excellent choice of energy storage.