Walking beam type reheating furnace is an essential part of the steelmaking process. These furnaces are used to heat steel billets, blooms, slabs, and beam blanks to a high temperature, which makes them easier to work with during the rolling process. The walking beam furnace is a type of continuous furnace that uses a system of beams to move the steel stock through the furnace.

Historically, walking beam furnaces have been used in the steel industry for over 50 years. They were first developed in the 1960s and have since become a popular choice for steel manufacturers due to their efficiency and reliability. The design of walking beam furnaces has evolved over the years, with advancements in technology and materials allowing for greater precision and control over the heating process.

The operational mechanism of a walking beam furnace involves a series of beams that move the steel stock through the furnace. The beams are made from heat-resistant materials such as ceramic fibers or refractory bricks. The furnace is heated using burners that are positioned above and below the beams. As the steel stock moves through the furnace, it is heated evenly and gradually to the desired temperature.

Key Takeaways

• Walking beam type reheating furnaces are used to heat steel billets, blooms, slabs, and beam blanks to a high temperature, making them easier to work with during the rolling process.
• Walking beam furnaces have been used in the steel industry for over 50 years and have evolved in design and technology over time.
• The operational mechanism of a walking beam furnace involves a system of beams that move the steel stock through the furnace, while burners positioned above and below the beams heat the steel stock evenly and gradually.

Historical Development of Walking Beam Furnaces

Walking beam furnaces have been in use for several decades and have undergone significant development over the years. The first walking beam furnace was developed by the United States Steel Corporation in the 1930s. This furnace was designed to reheat steel slabs before they were rolled. The furnace used a walking beam mechanism to move the slabs through the furnace.

Over the years, the walking beam furnace has undergone significant improvements in terms of design and operation. These improvements have been driven by the need to increase productivity, reduce energy consumption, and improve product quality.

One of the major developments in the walking beam furnace was the introduction of computer control systems. These systems allowed for better control of the furnace temperature and improved the accuracy of the slab positioning. This, in turn, led to better product quality and reduced energy consumption.

Another significant development in the walking beam furnace was the use of regenerative burners. These burners use waste heat from the furnace to preheat the combustion air, which reduces the amount of fuel needed to heat the furnace. This has resulted in significant energy savings and reduced greenhouse gas emissions.

Today, walking beam furnaces are widely used in the steel industry and are considered to be one of the most efficient and reliable types of reheating furnaces. They are used to reheat steel slabs, billets, and blooms before they are rolled into finished products. The walking beam furnace is also used in other industries, such as the aluminum industry, where it is used to heat aluminum ingots before they are rolled or extruded.

In summary, the walking beam furnace has undergone significant development over the years, driven by the need to increase productivity, reduce energy consumption, and improve product quality. Today, it is widely used in the steel industry and is considered to be one of the most efficient and reliable types of reheating furnaces.

Design Principles of Walking Beam Furnaces

Mechanical Components

Walking beam type reheating furnaces are designed to reheat long and flat products such as billets, blooms, beam blanks, and slabs. The furnace has a series of mechanical components that work together to move the steel products through the furnace. These mechanical components include walking beams, skids, and rollers.

The walking beams are the main mechanical component of the furnace. They are designed to support and move the steel products through the furnace. The walking beams are usually made of high-strength steel to withstand the high temperatures and stresses of the furnace. The walking beams are driven by hydraulic cylinders that move them back and forth.

The skids are another important mechanical component of the furnace. They are designed to support the steel products as they move through the furnace. The skids are usually made of high-strength refractory material to withstand the high temperatures of the furnace. The skids are also designed to minimize the contact between the steel products and the refractory material to reduce the risk of damage to the steel products.

The rollers are the final mechanical component of the furnace. They are designed to transport the steel products out of the furnace and onto the cooling bed. The rollers are usually made of high-strength steel to withstand the weight of the steel products.

Thermal Characteristics

The walking beam type reheating furnace is designed to provide uniform heating of the steel products. The furnace is divided into several zones, each with its own heating system. The heating systems are designed to provide the required amount of heat to each zone to achieve the desired temperature profile of the steel products.

The heating systems of the furnace include burners, recuperators, and heat exchangers. The burners are used to provide the heat required to raise the temperature of the steel products. The recuperators are used to recover the waste heat from the furnace and use it to preheat the combustion air. The heat exchangers are used to transfer the heat from the exhaust gases to the combustion air.

The furnace is also designed to provide a controlled atmosphere to prevent oxidation of the steel products. The atmosphere in the furnace is controlled by the use of flue gas recirculation and the injection of natural gas or propane. The controlled atmosphere helps to reduce the formation of scale on the surface of the steel products.

In summary, the walking beam type reheating furnace is a complex system that requires careful design and engineering to ensure reliable and efficient operation. The mechanical components and thermal characteristics of the furnace work together to provide uniform heating of the steel products and prevent oxidation and scale formation.

Operational Mechanism

Walking Beam Movement

The walking beam type reheating furnace is designed to heat steel slabs before they are rolled into sheets or other shapes. The furnace uses a walking beam mechanism to move the slabs through the furnace. The walking beam consists of a series of cranes that are connected to a central drive system. The cranes move the slabs through the furnace in a continuous loop. The slabs are supported by a series of rollers that move along with the walking beam.

Heating and Temperature Control

The reheating furnace uses a combination of burners and fans to heat the slabs to the desired temperature. The burners are located above and below the slabs, and they are fueled by natural gas or other fuels. The fans blow hot air onto the slabs to distribute the heat evenly.

The temperature of the furnace is controlled by a series of sensors that measure the temperature of the slabs as they move through the furnace. The temperature sensors send signals to a computer that controls the burners and fans to maintain the desired temperature. The computer also monitors other variables, such as the speed of the walking beam and the position of the slabs in the furnace.

Overall, the walking beam type reheating furnace is an efficient and reliable way to heat steel slabs. By using a combination of burners and fans, the furnace can heat the slabs to the desired temperature quickly and evenly. The walking beam mechanism ensures that the slabs are moved through the furnace smoothly and efficiently.

Materials and Construction

Refractory Materials

When it comes to the walking beam type reheating furnace, the refractory materials used play a crucial role in the performance and longevity of the furnace. The refractory materials used in the construction of these furnaces must be able to withstand high temperatures and thermal shock, while also having good insulation properties.

Typically, the refractory materials used in these furnaces include fireclay, high alumina, and silica. These materials are chosen for their ability to withstand high temperatures and their ability to provide good insulation. In addition, the use of these materials can help to reduce energy consumption and improve the efficiency of the furnace.

Structural Materials

In addition to the refractory materials used in the construction of the walking beam type reheating furnace, the structural materials used are also important. The structural materials used must be able to withstand the weight of the furnace and the materials being heated, while also being able to withstand the high temperatures generated during the heating process.

Typically, the structural materials used in these furnaces include steel and cast iron. These materials are chosen for their strength and durability, as well as their ability to withstand high temperatures. In addition, the use of these materials can help to reduce maintenance costs and improve the overall performance of the furnace.

Overall, the materials used in the construction of the walking beam type reheating furnace play a crucial role in its performance and longevity. By carefully selecting the appropriate refractory and structural materials, we can ensure that the furnace operates efficiently and effectively for many years to come.

Advantages of Walking Beam Furnaces

Walking beam furnaces offer several advantages over other types of reheating furnaces. Here are some of the benefits we have observed:

High Productivity

Walking beam furnaces are designed for high productivity. They can handle large quantities of steel products such as billets, blooms, beam blanks, and slabs at throughput rates ranging from 60 up to 500 t/h. Additionally, they can handle products weighing up to 67 tons.

Efficient Heating

Walking beam furnaces are highly efficient in heating steel products. The furnace is heated to the desired temperature for the heat treatment process using burners or other heat sources. The workpieces are elevated and supported by the walking beams as they move through the heated zones of the furnace.

Flexible Control

Walking beam furnaces offer flexible control over the heating process. They can be programmed to heat steel products to specific temperatures and hold them at those temperatures for specific durations. This level of control allows for precise heat treatment of steel products, resulting in improved quality.

Cost-Effective

Walking beam furnaces are cost-effective compared to other types of reheating furnaces. They offer high productivity and efficient heating at a lower cost. Additionally, they require less maintenance, resulting in lower operating costs.

Proportional Control

The Stein Reheating Walking Beam Furnace (WBF) is a cost-effective walking beam furnace with proportional control. This feature allows for precise control of the heating process, resulting in improved product quality. The proportional control feature also helps to reduce energy consumption and operating costs.

In summary, walking beam furnaces offer several advantages over other types of reheating furnaces. They are highly productive, efficient in heating, offer flexible control, are cost-effective, and feature proportional control.

Applications in Industry

Metallurgy

Walking beam type reheating furnace is widely used in the metallurgical industry for various purposes. One of the most common applications is for reheating steel billets, blooms, beam blanks, and slabs before rolling or forging. The furnace can handle a wide range of steel products, from long and flat to round and square. The walking beam design allows for a smooth and continuous movement of the steel stock through the furnace, ensuring uniform heating and minimal distortion.

The furnace is also used for heat treatment of steel products, such as annealing, normalizing, and tempering. These processes require precise control of the temperature and heating rate, which can be achieved with the walking beam type reheating furnace. The furnace can also be used for preheating of steel ingots before forging, which can improve the quality and yield of the final product.

Manufacturing Processes

Apart from the metallurgical industry, walking beam type reheating furnace is also used in other manufacturing processes that require high-temperature heating of materials. For example, the furnace can be used in the production of glass, ceramics, and refractory products. The furnace can also be used in the production of non-ferrous metals, such as aluminum, copper, and brass.

The walking beam type reheating furnace is especially useful in manufacturing processes that require continuous and uniform heating of materials. The furnace can be designed to handle a wide range of materials, from small and lightweight to large and heavy. The furnace can also be integrated with other equipment, such as quenching tanks and cooling systems, to provide a complete heating and cooling solution for the manufacturing process.

Maintenance and Safety Procedures

Maintaining a walking beam type reheating furnace is crucial to ensure its optimal performance and longevity. Regular maintenance procedures should be followed to prevent equipment failure and minimize downtime. The following are some of the maintenance procedures that we recommend:

• Regular cleaning: The furnace should be cleaned regularly to remove any debris that may accumulate on the walking beams, skids, and other components. This will prevent damage to the furnace and ensure smooth operation.
• Lubrication: All moving parts of the furnace should be lubricated regularly to prevent wear and tear. This will also reduce friction and ensure smooth operation.
• Inspection: The furnace should be inspected regularly to identify any signs of wear and tear. Any damaged components should be replaced immediately to prevent further damage.
• Calibration: The furnace should be calibrated regularly to ensure that it is operating within the required parameters. This will prevent overheating and equipment failure.

Safety procedures should also be followed to prevent accidents and injuries. The following are some of the safety procedures that we recommend:

• Personal protective equipment: All personnel working on or around the furnace should wear appropriate personal protective equipment, including gloves, safety glasses, and hearing protection.
• Lockout/tagout: The furnace should be locked out and tagged out before any maintenance or repair work is performed. This will prevent accidental startup and ensure the safety of personnel.
• Fire prevention: The furnace should be equipped with fire prevention systems, including fire extinguishers and smoke detectors. Regular fire drills should also be conducted to ensure that personnel know how to respond in case of a fire.

In conclusion, regular maintenance and safety procedures are essential to ensure the optimal performance and safety of a walking beam type reheating furnace. By following these procedures, we can prevent equipment failure, minimize downtime, and ensure the safety of personnel.

Technological Advances and Future Outlook

Over the years, walking beam type reheating furnaces have undergone significant technological advancements to improve their performance and efficiency. These advancements include the use of advanced control technology, improved combustion systems, and the integration of energy and exergy analysis to gain insight into their performance.

In particular, the use of advanced control technology has enabled walking beam type reheating furnaces to achieve better temperature control, reduce fuel consumption, and minimize scale formation. This technology has also enabled the furnaces to operate more efficiently and with greater reliability, resulting in improved product quality and reduced operating costs.

Another significant advancement in walking beam type reheating furnaces is the integration of energy and exergy analysis. This approach provides a more comprehensive understanding of the furnace’s performance by considering both the energy and exergy flows within the system. By analyzing these flows, it is possible to identify areas of inefficiency and develop strategies to improve furnace performance and reduce energy consumption.

Looking to the future, there is still considerable scope for further advancements in walking beam type reheating furnaces. For example, the integration of artificial intelligence and machine learning technologies could enable these furnaces to operate with even greater efficiency and reliability. Additionally, the use of alternative fuels and renewable energy sources could help to reduce the environmental impact of these furnaces.

In summary, walking beam type reheating furnaces have undergone significant technological advancements in recent years, resulting in improved performance and efficiency. Looking to the future, there is still considerable scope for further advancements, and we are excited to see how these furnaces will continue to evolve and improve in the years ahead.

Frequently Asked Questions

How does a walking beam reheating furnace operate?

A walking beam type reheating furnace operates by using a series of walking beams to move the steel slab through the furnace. The walking beams are driven by a motor and are designed to move the slab at a constant speed. As the slab moves through the furnace, it is heated by a series of burners that are located above and below the slab. The burners are controlled by a computerized system that ensures that the slab is heated evenly and to the desired temperature.

What are the advantages of using a walking beam furnace for reheating slabs?

The advantages of using a walking beam furnace for reheating slabs include high productivity, excellent temperature uniformity, and low pollutant emissions. Walking beam furnaces are also highly efficient and can be used to reheat a wide range of steel products, including billets, blooms, beam blanks, and slabs.

What are the main components of a walking beam type reheating furnace?

The main components of a walking beam type reheating furnace include walking beams, burners, skids, and a computerized control system. The walking beams are used to move the steel slab through the furnace, while the burners are used to heat the slab. The skids are used to support the slab as it moves through the furnace, and the computerized control system is used to ensure that the slab is heated evenly and to the desired temperature.

How does the efficiency of a walking beam furnace compare to other types of reheating furnaces?

The efficiency of a walking beam furnace is generally higher than other types of reheating furnaces, such as pusher furnaces and rotary hearth furnaces. This is because walking beam furnaces are designed to heat the steel slab evenly and to the desired temperature, which reduces energy waste and improves overall efficiency.

What factors influence the cost of installing and operating a walking beam type reheating furnace?

The cost of installing and operating a walking beam type reheating furnace can be influenced by a variety of factors, including the size of the furnace, the type of fuel used, and the cost of labor. Other factors that can impact the cost of installation and operation include the cost of maintenance and repairs, as well as any environmental regulations that may apply to the furnace.

Can you explain the maintenance requirements for a walking beam reheating furnace?

The maintenance requirements for a walking beam reheating furnace can vary depending on the specific design and configuration of the furnace. However, some common maintenance tasks may include regular cleaning of the burners and skids, as well as periodic inspections of the walking beams and other structural components. It is also important to ensure that the computerized control system is functioning properly and that any necessary repairs are made in a timely manner.