Use of Industrial Heating Appliances in the Food Industry

Food Industries and Vegetable Oil Viscosity  

Immersion heaters are used in many industrial processes to heat fluids like water, oils, solvents, salts and gases. Many industries like the oil and gas, petrochemical, transportation and process industry use heating devices for a variety of purposes. The food industry also makes use of these immersion heaters to maintain the temperature of certain food groups.

Vegetable oil is an important fluid that requires proper temperature maintenance as it tends to become viscose with high temperature, which as a result, hampers the overall industrial process flow. Hence, immersion heaters are used by the food industry to maintain temperature of vegetable oil and certain food groups.  

Industries that manufacture kitchen appliances use these heating devices to regulate the temperature of food groups. Screw Plug Immersion heaters are used by steam tables. The tubular heating plates of the heaters are equipped with thermocouples that help monitor temperature changes and maintain optimum temperature required for preparing food. These heating devices are a cost effective solution for maintaining temperature of food groups and have a variety of other applications in the food industry. These electrical heating devices are significant in the food industry as they have value in the service as well as in the food-processing arena.  

Other applications of immersion heaters in the food industry include their use in buffet service. Buffet tables make use of screw plug immersion heaters whose heating elements are made of stainless steel to provide even heat distribution to the required area. Cabinets used for storing equipment make use of immersion heaters with the heating elements directly installed along the sides of the cabinet for quick and efficient heat transfer for maintaining constant temperature.  

In the food industry, other applications that use immersion heaters for heating include cooking tables, kitchen appliances like dishwashing equipment, stands and installations for cabinets and racks.


Immersion heaters  

Fig1: Screw Plug Immersion heater used in Food Industry

Immersion Heaters are industrial heating appliances that are used by many industrial processes for maintaining fluids temperature. Many industries including the food industry make use of these electric heating devices to meet their heating environment requirements. Immersion heaters come in various sizes, shapes and watt density. They are low cost, efficient and reliable heat transfer solutions that can be customized to suit your specific requirements.       

The heating element is directly immersed within the container to provide direct heat to the substance inside in a quick and efficient manner. A digital control panel accompanies the heater that contains the controls to regulate heater operations. The thermocouple attached to the control box helps in maintaining optimum temperature and prevents fluid from overheating. Different type of immersion heaters include flanged heaters, screw plug heaters, circulation heaters and over the side heaters.    


Process Heating  

In the process Industry, flanged immersion heaters are used to heat up liquids in a quick and efficient manner. These heating assembly lines have digital control boxes that regulate heat transfer and ensure liquid heat up in quick time. Most industrial processes have a nonconventional industrial environment and require outdoor operations. For such an industrial environment, special immersion heaters with NEMA 4 and NEMA 7 control panels are used that have heating elements made up of special alloy materials that provide resistance to moisture, humidity and other climatic hazards.  

These special digital control panels provide protection against hazardous situations. Industries that have to operate in areas that have safety risks due to the hazardous elements being used make use of such special immersion heaters that are designed to provide protection in such environment. An example of such an industry is the petrochemical industry.  

There are many applications that make use of process immersion heaters depending on the temperature range and technical specification of each heater. These heaters have control mechanisms that monitor the overall heater performance and help regulate heat transfer. Immersion heaters are mostly used to provide quick and even heat distribution to fluids and gases in the industrial processes.  


Vegetable Oil Viscosity  

The most important element that requires heating in food Industry is vegetable oil. Large food processing operations require heating of vegetable oil that becomes less viscous with increasing temperature. With increased viscosity, the oil becomes thick and adhesive. This makes the fluid circulation difficult and hampers the quality of the industrial process. The amount of heating also affects the viscosity of any other liquid involved in the process.

Fig2: Effect of Temperature on Vegetable Oil Viscosity

Viscosity is a measure of a liquid’s resistance to flow. Fluids pose resistance to the movement of materials immersed through them and to the movement of layers within them that have varying velocities. Viscosity of a fluid is relatively unaffected by pressure but with extreme liquid pressure viscosity might increase. The molecule of a liquid are not pressed closer together with increased pressure as fluids are normally incompressible. Most fats like margarine and butter are more viscous and appear thick solids rather than flowing fluids.  

Viscosity of a liquid is largely dependent on temperature and change with varying temperature ranges. Viscous food groups like honey and syrups can be made less viscous by treating them to a little heat, which will turn them into soft flow liquids. Vegetable oil has a liquid state at room temperature. For food processing viscous vegetable oil becomes a hassle as the thick solidified material become difficult to process hence proper heating is required to maintain the vegetable oil temperature to ensure smooth processing.  

Normally, the viscosity of a fluid will decrease with an increase in temperature. This is because with an increase in temperature, the movement of the liquid molecules increases and there is lesser contact time with neighboring molecules. This in turn results in a decrease in average intermolecular forces and hence in the liquid’s viscosity. Because the vegetable oil is made of fats extracted from plants, therefore the chemical composition of the fats results in oil viscosity. To decrease the viscosity of vegetable oil food industries make use of immersion heaters or oil heaters to provide quick heating for the oil that eventually results in a decrease in the fluid’s viscosity making it easier for processing.