by Clarissa Muliawan, M.Eng | Fri, 24 January 2025
Types of Heat Treatment Furnaces & Ovens
What is a Heat Treatment Oven/Furnace?
A heat treatment furnace/oven are designed to regulate atmospheric temperatures to which materials, such as steel and aluminum is soaked into, based on specific heat treatment requirements. These requirements include heating, holding, and cooling conditions. By processing metals within a heat treatment furnace and oven under controlled conditions, desired properties like hardness and toughness can be achieved.
Heat treatment equipments primarily perform two functions: heating and cooling. The heating function involves methods and atmosphere gases, while the cooling function depends on cooling methods and materials. These furnaces are essential in industries such as automotive and machinery manufacturing, with heat-treated parts constituting approximately 80% of their output. In Indonesia, heat treatment is a specialized field, supported by subcontracting manufacturers that process raw materials and finished products.
Batch-type Furnace & Ovens
This furnace type uses a conveying device to load and unload products. Materials are placed in trays or baskets, managed by residence time, and then transported. Batch furnaces are ideal for producing small quantities of varied products. The BH-HTO-05 bogie-hearth oven below is used for the batch-type normalizing treatment to various industrial pumps.
Continuous-type Furnaces & Ovens
A continuous furnace uses a conveyor system, such as a mesh belt or tray pusher, to move products through the heating chamber. It is suited for mass production of uniform products. The continuous annealing oven below is used in the annealing of stator assy.
Furnaces & ovens can both rely on heaters (electric types) or burners (combustion types) as the heat source. Commonly, our products uses electricity or LNG as an input. Heat output is calculated based on the required heating speed, heat loss, and the material being heated. Over- or under-designed systems can either increase costs or cause production delays.
The heating chamber raises materials to a specific temperature. Fans circulate air to ensure uniform heating, while insulation materials, such as refractory bricks for furnaces, or mild steel with insulation for ovens. All this is designed minimize heat loss and reduce energy costs. Sensors are often installed to detect equipment malfunctions and avoid significant losses.
Electric Furnace
Electric furnaces are valued for their precise temperature control, achieved through methods like direct heating. These furnaces are ideal for treatments such as tempering, quenching, and nitriding.
Combustion Furnace
Combustion furnaces generally uses LNG-based burner systems for both direct or indirect heating. They are suitable for processing large quantities but require safety measures like flame and gas detectors to prevent hazards.
Cooling processes vary based on the medium used:
How are heat-treated products inspected?
Inspections involve destructive tests (e.g., hardness testing, microstructure analysis) and non-destructive tests (e.g., X-rays, ultrasonic waves) to ensure desired properties.
How is furnace temperature measured?
Thermocouples, such as K-type or R-type, are commonly used. Temperature control is often achieved using PID systems integrated with the furnace’s control panel.
How to determine the lifespan of a heating furnace?
Degradation in insulation and structural components increases heat loss and energy costs. Monitoring power consumption and equipment condition helps determine replacement timing.
Summary
Heating furnaces are essential for industrial heat treatment processes, with their configuration varying based on requirements. Electric furnaces offer precise temperature control, while combustion furnaces are suited for large-scale production but require stringent safety measures. Cooling systems must align with the heat treatment conditions to achieve optimal results.
At Suhatherm Manufacturing Indonesia, we specialize in designing and manufacturing industrial heating furnaces tailored to your specific needs. With experience in building over 1,500 industrial furnaces, we also offer technical consultations. Feel free to contact us for more information.
