Industrial ovens are thermal processing machines. Ovens use heat to treat materials in many ways. The name for a given heat treatment process reflects the kind of property changes that occur in a product when it is heated; drying, baking and dehydrating are processes of moisture removal, curing is the process of strengthening and firing is the process of hardening ceramics. Industrial ovens are also used to activate adhesives, gel and fuse materials together, heat-set, heat-shrink, preheat, sinter, melt, laminate and thermal bond other materials.
Industrial ovens may be used for a broad variety of applications. These include powder coating, drying, baking, curing, and many others. These ovens have a wide range in temperatures that they are capable of reaching. Higher temperature industrial ovens may be used for drying materials and are sometimes also called a kiln; though they do not reach temperatures quite as high as traditional ceramic kilns. Lower temperature industrial ovens may be used for baking or curing and are found in places such as factories or bakeries. Industrial ovens come in many shapes and sizes, some come designed similar to a home oven, while others are large enough for people to walk into. There are also some industrial ovens which have a conveyor running through them in order to heat mass quantities of items over a short span of time.
Industrial ovens vary greatly in size and shape. There are the very large that contain many shelves and could be used for baking many loaves of bread at once. Ovens may be installed into large trucks or on carts for ease of portability. The one thing all of these ovens have in common is they are all temperature controlled based on their purpose. There are industrial ovens that are specifically designed to remove the moisture from objects that are placed inside, these are called drying ovens. Industrial ovens designed for curing are made to cause chemical reactions between the coating and the actual product itself. Like ovens found in homes, some industrial ovens are designed for specifically for food production. Although typically the industrial ovens used for food production are much larger and reach temperatures much higher than the average domestic oven the concept of baking food is the same.
The processes employed by industrial ovens require heat and
mass transfer, which can be accomplished by gas-fired and electric ovens, both
of which can use conduction, convection, or radiant infrared heat as a means of
heat generation. Some industrial ovens are designed to utilize a combination of
these types of heat generation; no single heating technology is perfect for
every process. Industrial oven manufacturers offer two oven configurations:
batch ovens, which range in their production volume capacities and can be
portable, and continuous or conveyor ovens, which are generally limited to
large-scale heat treatment operations. Batch ovens are more commonly employed
in commercial settings where an individual product is processed in large
groups. Continuous conveyor ovens consist of automated conveyor systems that
move large quantities of products through a heating chamber. Both batch and
continuous ovens may be used as curing ovens, drying ovens, powder coating
ovens or sintering ovens while vacuum ovens heat metals within a
convection-preventing vacuum at high temperatures. While many industrial ovens
are used in manufacturing and food processing settings, some laboratory ovens
have applications in industries that conduct heat-related research or who develop
new oven or heat treatment technologies.
Heat treatment is a very important industrial process. Industries that produce metal, plastic, wood, ceramic and glass products all rely on heat treatment processes to strengthen or otherwise improve the quality of their products. Industrial oven manufacturers create oven configurations that are suitable for varied heat treatment processes. Products like coated paper, textiles, carpeting, building materials, tubing, electronics, fuel cells, steel coils and automotive parts all require some kind of heat treatment before they reach their end-users. Because of the expansive variety of products that undergo heat treatment processes, an equally large variety of ovens is necessary to meet that need. Industrial ovens are divided into two main groups: batch and conveyor ovens. Batch ovens are popular with smaller-scale industrial heat treatment service providers because they allow for an even application of heat for a volume of products. They can be small and portable, or they can be large enough to fill most of a room. Some batch ovens allow for the evacuation of atmosphere in the oven's enclosure (such ovens are called vacuum ovens). This process allows for the heat treatment of metals without the risk of surface oxidization, which can occur in the presence of oxygen. Conveyor ovens are more useful in large-scale heat treatment operations because they allow for the heat treatment of a continuous stream of products. They can be less attractive to smaller operations because of their high initial cost compared to many batch ovens. They also require a steady stream of product input in order to be cost-effective.
Both oven configurations can use a variety of heating methods. The simplest form of heat transfer in industrial ovens is natural convection. Convection is the transmission of heat through gasses and liquids. In a natural convection oven, an electrified coil or gas-fired heat source produces heat that is transferred to the air in the oven's enclosure. That heat is then transferred to the product. Natural convection is sufficient in many small ovens, but when batch size increases, natural convection is likely to heat products unevenly. The solution to the unevenness of natural convection is forced convection. This solution involves a fan in the oven's enclosure that circulates the heated air around the product, resulting in an even distribution of heat. Most baking operations of any substantial scale require forced convection in order to be effective. The most efficient means of heat generation is infrared radiation. Ovens equipped with infrared heat sources use electromagnetic waves to transfer heat directly to products as opposed to through the air and then to the product. Heat in infrared ovens is generated in a coil, often a tungsten filament, and transfers directly to the product. Because of their high efficiency, infrared ovens are popular in all industrial heat treatment applications. A few, more obscure methods of heat generation exist (quartz is used in some conveyor ovens to produce intense light), but their use is limited.
Understanding heat transfer is an important part of understanding how ovens work. When an object is heated, the heat causes molecular activity in the object to speed up. In solids, the molecules in lattices vibrate, and in gasses, molecules collide. Laboratories use industrial ovens to study heat transfer and refine the means of its transmission in industrial contexts. As time has passed, inefficiencies in heat transmission have been eliminated, new methods of producing heat have been developed and new applications for heat treatment processes have been discovered. The result of this research has been stronger metal products, more versatile extruded polymer products, improved sanitation in healthcare facilities and a host of other benefits.
Industrial Oven Terms
Aging - The process of changing the properties of a metal or an alloy through temperature changes through the utilization of an industrial oven.Annealing - The process of softening an object or changing other properties of the object through cycles of heating and cooling using an industrial oven.
Postheating - Applying heat to an object after the manufacturing
process, such as brazing, welding or soldering.
Powder Coating - A dry finishing process that utilizes finely ground, electrostatically charged particles, which are sprayed onto a part to be coated. When placed in an industrial oven, the charged parts melt and fuse into a durable, even coating.
Preheating - The application of heat in industrial ovens before the manufacturing process.
Process Heating - The supplication of heat from industrial ovens to an object or material.Quenching - The rapid cooling of an object heated in an industrial oven.