Flat tubular heaters boost fryer efficiency

FROM fryers to griddles to ovens, heat is an important in most foodservice applications. When it comes to the heat source for frying, not all heating elements are created equal. Electric fryer heaters can be segmented into two broad categories - round tubular heaters and flat tubular heaters. When first introduced, fryer heaters were round tubular, but engineers found that a flat tubular design offered many benefits - the most important being that the shape lifts the oil into the cook zone far better than round heaters. An innovation was born - incorporating these efficient features. Flat surface geometry. Because of its design and geometry, flat tubular heaters will heat viscous fluids from ambient temperature faster than round tubular elements with the same wattage and at a lower sheath temperature. As the graphic shows, the round tubular has a much more erratic flow pattern due to the tubular''s round shape, which causes a wider and less efficient flow of liquid around the heater surface. In contrast, the flow pattern around the flat tubular heater is streamlined; the flat surface has less restriction on the liquid as it moves up and past the heater sides. This efficient and faster flow pattern permits the liquid to move heat away from the sheath very quickly, resulting in the flat tubular heater''s lower operating sheath temperature. Greater buoyancy force. This natural convection phenomenon partially depends on the ratio of a buoyancy force to the viscous force of the fluid being heated. The length of the heater sides mainly determines the buoyancy force or the flow of liquid up and across the heater surface. The side of a flat tubular heater is typically 25mm (1 inch), compared to the 10.9mm (0.43 inch) or less dimension of a round tubular element. The flat tubular heater''s smaller edge and longer side creates a buoyancy force up to ten times greater than a round tubular heater depending on the material being heated. Smaller dimension norma l to flow. Typically, a narrower dimension will give a smoother and faster liquid flow. For example, the round tubular''s wide dimension, nearly a half-inch, inhibits the flow of liquid. It causes currents that disrupt the flow and the flow rate is somewhat slower. The flat tubular heater, on the other hand, has a much thinner dimension (5.97 mm), which reduces the drag forces on the liquid flowing past the heater. This allows the liquid to move past the flat heater faster than the round heater. The end result the flat tubular gets the heated liquid into the work zone faster than when using a round tubular. The flat tubular heater also has about a 50% greater surface area than a round tubular. This is the key to lowering watt density for the same length heater or reducing the heater size while maintaining the same watt density.Designers Sneakers