Heating Solids Heating a solid can be accomplished using any of several heater types and/or a combination of types. Some heater types physically lend themselves more readily to an application than others, depending on the object’s shape, size and mass, as well as performance requirements. The application descriptions below will give you a general idea on how a particular heater type is applied to heating a solid and some common examples. Categories
Heating Liquids Heating a liquid can be accomplished using any of several heater types and/or a combination of types. Some heaters physically lend themselves to direct immersion in the liquid, while others are better suited for heating a pipe or vessel containing the liquid. The application descriptions below will give you a general idea on how a particular heater type is applied to heating liquids and some common examples. Categories
Heating in a Vacuum Heating a vacuum isn’t possible. There is nothing to heat. When referring to “heating a vacuum,” we mean heating an object located inside a vacuum. Regardless of the heater type, all vacuum heating is accomplished with radiant heating. Some heater types physically lend themselves more readily to an application than others. The application descriptions below will give you a general idea on how a particular heater type is applied for heating an object inside a vacuum. Categories
Heating Gases Heating a gas can be accomplished using any of several heater types and/or a combination of types. Some heaters physically lend themselves to direct immersion in the gas stream, while others are better suited for heating a pipe or vessel containing the gas. The application descriptions below will give you a general idea on how a particular heater type is applied to heating gases and some common examples. Categories
Heater Selection Guide What is Heating – The Three Heating Methods Heating an object or substance involves increasing the amount of thermal, or molecular kinetic energy. Heat energy always flows from hot regions to cold regions until an equilibrium is achieved. At that point, “heating” the cooler region ceases and an isothermal state is achieved.In a strict sense, heating can only be accomplished in two ways; conduction and radiance. Convection is a type of conduction heating.Below are some quick definitions and hints: Conduction The mode of heat transfer within a substance or by solids in direct contact with each other when a temperature difference exists. Conduction heating is most influenced by how easily the heat travels through the substance–its thermal conductivity–and how much mass there is to absorb the heat energy. Convection The mode of heat transfer associated with conduction in which heat is transferred from a higher temperature region in a fluid (liquid or gas) to a lower temperature region. This is accomplished through buoyancy. As the heated fluid in contact with a heat source expands, it develops less weight per unit volume and rises; and is replaced by the surrounding, cooler, heavier fluid. This results in movement of masses within the fluid to create convection currents. Influencing convection heating are the fluid’s permissible watt densities, thermal conductivity and expansion coefficient. Radiance The heating process that directs radiant energy, in the form of electromagnetic waves, onto an object. The earth is heated by the sun’s radiant energy. While all electromagnetic waves will “heat,” the most useful heating energy is contained in the infrared portion of the electromagnetic spectrum. Radiant heating is most often used for heating solids and liquids. Gases are generally unaffected due to their transparent nature. The major factors in radiant heating are the distance between object and heat source, and how well it absorbs radiant energy. For instance, a dark, matte finish is more absorbent than a light, bright polished surface.
Thermostats and Accessories Watlow designs and manufactures all of the components of a thermal system. This allows Watlow to recommend, develop and deliver the optimal thermal solution of customer’s equipment. Product Description SERIES EHG Includes a compact temperature control, thermocouple sensor and power switching device integrated into a heater’s power cord used to control process temperatures. SERIES EHG SL10 Integrates a heater, an adjustable set point temperature controller, high/low temperature alert, power switching device and high temperature safety limit all within the power cord system. ST10 and ST207 Pre-set thermostats used with flexible heaters are available mounted to the heater or as a separate device used to control process. Sensors A full range of thermocouple, RTD and thermistor sensors are available for integration into the heater construction or mounted remote to monitor process or heater temperature. Bulb and Capillary Regulates temperature in non-critical applications within a preset range and cycles heaters on and off. Low Liquid Level Sensors These sensors protect heating systems by determining low levels of fluid. The sensors can be connected to a variety of controllers, alarms or limit protection devices.
Radiant Heaters Watlow’s diverse radiant heater line provides a solution for almost any application requiring radiant heat. Watlow’s capabilities cover a wide range of needs, from contamination-resistant panel heaters to rugged tubular elements and high temperature ceramic panels. Product Material Maximum Operating Temperatures Maximum Watt Densities °F °C W/in2 W/cm2 RAYMAX Panel Stainless steel 2000 1095 30 4.7 Band and Strip Emitters Stainless steel 1300 700 30 4.7
Nozzle Heaters Watlow offers a full line of hot runner nozzle heaters for the plastics industry as well as slip-on heaters for the medical and analytical industries. While every heater has a unique set of capabilities, each nozzle heater is designed to meet specific application requirements. Whether an application requires high performance, high temperature or high watt density Watlow has the heater to fit the application. Product Material Maximum Operating Temperatures Maximum Watt Densities °F °C W/in2 W/cm2 Mineral Insulated Nozzle Stainless steel 1400 760 230 35.6 Pre-Coiled Cable Nozzle Stainless steel 1200 650 152 23.5
Band / Barrel Heaters Watlow’s line of band/barrel heaters are available for fast delivery and can be easily installed into original equipment manufacturer (OEM) and end user applications. This variety of heaters allows the user to specify the construction needed to result in the best heat solution. Product Material Maximum Operating Temperatures Maximum Watt Densities °F °C W/in2 W/cm2 Mineral Insulated Band Stainless steel 1400 760 100 15.5
Strip / Clamp-on Heaters Watlow’s strip/clamp-on heaters are a versatile solution for a number of applications. They can be bolted or clamped to a solid surface for freeze and moisture protection, food warming and other applications. These heaters make use of the most advanced heat construction techniques. Product Material Maximum Operating Temperatures Maximum Watt Densities °F °C W/in2 W/cm2 Mineral Insulated Strip 304 Stainless steel 1400 760 140 21.7 375 Strip Heaters Aluminized Steel 1100 595 100 15.5 FIREBAR Clamp-On Incoloy® 1400 760 120 18.6 304 stainless steel 1200 650 120 18.6 Thick Film Conduction 430 stainless steel 1025 550 75 11.6
