Sizing Heating and Cooling Coils
Why is it important for you to know this?
Twisting, turning tubes in tanks of steamy, colorful liquids. It is no wonder many still consider designing heat transfer equipment a type of sorcery. Most finishers work diligently at perfecting the chemical, physical and production details required for consistent quality finishes, and they understand that temperature control is critical. However, few fully understand how to specify heat transfer equipment and how the design affects production and operating costs.
Specifying heating equipment does not need to be confusing. Factors that affect how you boil a pot of water for spaghetti are the same as those influencing heat transfer equipment in the finishing shop. How much water is in the pot? How long should it take to heat up? How hot will the water get? How hot is the burner? How much of the pot is in contact with the burner?
These factors, along with the kind of material heated and how well it is mixed, are used to turn "a little of this and a pinch of that" into precise measurements. Simple calculations determine the proper size heating coil and can help solve a heat-transfer problem.
A few simple equations
Equation No. 1 combines all the factors that determine the surface area of the heat transfer device.
A = Q/U