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Heating Furnace 2 ~ Classification by Structure
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Overview.
In terms of furnace construction, there are two types: the versatile batch type and the continuous type suitable for mass production, which are further subdivided and used for different purposes.
01 Batch Type and Characteristics
Atmosphere heat treatment furnaces are the most versatile and widely used from general heat treatment to surface heat treatment such as surface hardening and nitriding. Batch type and continuous type They can be classified into batch type and continuous type based on their structure.
| Types of heat treatment furnaces | outline | Main applications (excluding carburizing and nitriding) | |
| batch style | Box-type furnace (muffle furnace) | Typical batch type, box-type heating furnace | Annealing, tempering, hardening and tempering of various parts |
| Bell Furnace (Covered Furnace) | Furnace heated with a cover over the processed materials on the furnace floor to keep them confidential | Annealing of coiled wire and steel plate | |
| Pit-type furnace | Furnaces mostly installed in underground pits, suitable for long products | Hardening and annealing of rolls and other long products | |
| continuous expression | Tray pusher type furnace | Heating furnace with trays conveyed by pushers from the inserted end of the furnace | Annealing, tempering, and hardening of machine parts, automotive parts, etc. |
| Roller Hearth Furnaces | Heating furnace that conveys first-time materials in the furnace by means of rotating rollers | Annealing, tempering, and hardening of steel pipes, steel, etc. | |
| Mesh belt furnace | Heating furnace with a mesh belt to transport processed materials inside the furnace | Hardening and tempering of relatively small items such as bolts and nuts | |
| Shaker hearth furnace | Heating furnace in which treated materials are transported in the furnace by vibration | Hardening and tempering of relatively small items such as bolts and nuts | |
| Opening Retort Shaped Furnace | Heating furnace in which processed materials are conveyed by rotating cylindrical retorts | Hardening and tempering of small items with simple shapes such as bearings and pins | |
Batch-type furnaces are suitable for a wide variety of products in small quantities and are widely used for various types of heat treatment. The most common heat treatment furnaces are Box type furnace and Muffle Furnace and is often used for quenching and tempering of various products. As an example, the figure below shows a schematic of a batch-type multipurpose box furnace. This heat treatment furnace can be used for various types of heat treatment, such as annealing, quenching, tempering, carburizing and quenching, and nitriding.
Others heat the processed materials placed on the furnace floor by covering them with a bell-shaped cover Bell-shaped furnace Most of the furnace body is stored in an underground pit Pit-type furnace The former is used for annealing coiled materials, while the latter is used for long or small materials. The former is used for annealing coiled materials, while the latter is used for quenching, carburizing, and nitriding of long or small parts.
02 Types and Features of Continuous Type
The continuous type is a furnace that continuously inserts processed materials and is suitable for mass production of the same processed materials, and is available in tray pusher type, roller hearth type, mesh belt type, shaker hearth type furnaces, rotary retort type, etc., depending on the conveying method in the furnace.
Tray pusher type The tray pusher type is a pusher that pushes trays or baskets sequentially in the furnace. They are especially suitable for heavy or long products and are mainly used for annealing and tempering.
Roller hearth type is suitable for annealing and tempering of long products because the material is conveyed by rotation. Mesh belt type and Shaker hearth type are often used for quenching, tempering, and carburizing when processing large quantities of relatively small parts such as bolts.
Rotary retort type is effective for uniform processing of small items, but is limited to simple-shaped items because it is prone to deformation.