Application of double chamber furnace melting technology in recycled aluminum industry

Application of double-chamber furnace melting technology in recycled aluminum industry

Application of double-chamber furnace melting technology in recycled aluminum industry

1. Overview of Double Chamber Furnace Melting Technology

Double chamber furnace melting technology is an efficient method for regenerating aluminum.

It distributes the preheating, melting and insulation of scrap aluminum in multiple independent furnace chambers to improve melting efficiency, reduce energy consumption and reduce metal burning.

The double chamber aluminum melting furnace usually consists of a heating chamber and a feeding chamber.

A partition wall connects the two furnace chambers, and a channel is provided on the partition wall for the circulation of furnace gas and aluminum liquid.

2. The structure and working principle of double chamber furnace

2.1 structure

Heating chamber: responsible for quickly raising the temperature of aluminum liquid, usually equipped with tangentially arranged burners to heat the aluminum liquid evenly and fully.

Feeding chamber: responsible for preheating and preliminary melting of scrap aluminum, usually equipped with a preheater to preheat scrap aluminum using flue gas waste heat.

Partition wall: separates the heating chamber from the feeding chamber, and a channel is provided on the partition wall for the circulation of furnace gas and aluminum liquid.

Circulating mixer: used to stir aluminum liquid to ensure uniform temperature and composition of aluminum liquid.

Air preheater: uses flue gas waste heat to increase the temperature of combustion air, improve combustion efficiency, and reduce energy consumption.

2.2 Working Principle

Preheating stage:

The scrap aluminum is first preheated in the feed chamber, and the preheating temperature is usually between 300℃-500℃.

The preheated scrap aluminum can reduce energy consumption and burning loss during the melting process.

Melting stage:

The preheated scrap aluminum enters the heating chamber through the channel on the partition wall.

The heating chamber quickly melts the scrap aluminum through the high-temperature heat source provided by the burner, and the temperature is controlled between 720℃-760℃.

Aluminum liquid circulation:

The aluminum liquid between the heating chamber and the feed chamber is circulated by an electromagnetic pump or a mechanical pump to ensure that the temperature and composition of the aluminum liquid are uniform.

This circulation stirring effect can improve the melting efficiency and reduce metal burning loss.

 Holding stage:

The molten aluminum liquid enters the holding chamber and is kept in an appropriate temperature range, usually between 700℃-720℃, for subsequent casting or processing.

3. Advantages of double-chamber furnace melting technology

⭐Low energy consumption

Preheating energy saving:

The scrap aluminum is preheated in the feed chamber, and the residual heat of the flue gas is used to significantly improve the thermal efficiency and reduce energy consumption.

When the preheated scrap aluminum enters the heating chamber, the required melting energy is greatly reduced.

Air preheating:

The air preheater uses the residual heat of the flue gas to increase the temperature of the combustion air, improve the combustion efficiency, and further reduce energy consumption.

The preheated combustion air can increase the flame temperature and reduce fuel consumption.

⭐Low burning loss

Immersed melting:

The scrap aluminum is immersed in the aluminum liquid in the heating chamber to melt, avoiding direct contact with the flame and significantly reducing oxidation burnout.

The burnout rate is usually between 0.6% and 1.0%, which is much lower than the 20% of the traditional single-chamber furnace.

Clean liquid surface melting:

The heating chamber maintains a clean liquid surface and regularly removes scum, further reducing oxidation burnout.

⭐High recovery rate

Rapid melting after preheating:

The preheated scrap aluminum melts quickly in the heating chamber, which reduces the melting time and improves the metal recovery rate.

The metal recovery rate can usually reach more than 90%.

⭐High melting rate

Preheated scrap aluminum:

When the preheated scrap aluminum enters the heating chamber, the melting rate is significantly increased and the melting rate is fast.

Large aluminum liquid circulation volume:

The aluminum liquid is circulated through an electromagnetic pump or a mechanical pump to ensure that the temperature and composition of the aluminum liquid are uniform, further increasing the melting rate.

⭐Strong adaptability

Adaptability to crushed materials:

The preheater exhaust improves the adaptability of the vertical furnace to crushed materials, which is suitable for UBC, chips, baled aluminum chips, baled materials and crushed materials.

Processing of various aluminum scraps:

The double-chamber furnace can process different types of aluminum scraps at the same time, such as thin aluminum scraps and large pieces of aluminum scraps, which improves the flexibility and adaptability of the equipment.

4. Application cases of double-chamber furnace melting technology

Aluminum profile industry

Application background:

A large amount of process scrap is generated during the processing of aluminum profiles, and these scraps need to be recycled efficiently.

The application of double-chamber furnaces in the aluminum profile industry can significantly improve the recovery rate and quality of waste.

Specific application:

Double-chamber furnaces are used to treat process scraps in aluminum profile processing, such as scraps, aluminum chips, etc.

Through preheating and immersion melting, the recovery rate of scraps is significantly improved and the burn loss rate is greatly reduced.

For example, the 100,000-ton UBC recycling project in Aipusheng has an output rate of about 85%.

Benefiting from the improvement of recycled aluminum recycling technology, the liquid aluminum output rate of newly built or newly put into production recycled aluminum re-grade utilization projects in China has increased to about 87-90%.

Auto parts industry

Application background:

A large amount of scrap aluminum is generated during the manufacturing process of auto parts, and this scrap aluminum needs to be recycled efficiently to reduce production costs and environmental impact.

The application of double-chamber furnaces in the automotive parts industry can significantly improve the recovery rate and quality of scrap aluminum.

Specific application:

Double-chamber furnaces are used to process scrap aluminum in the manufacturing of automotive parts, such as engine blocks, cylinder heads, pistons, etc.

Through preheating and immersion melting, the recovery rate of scrap aluminum is significantly improved and the burn-off rate is greatly reduced.

For example, the compound method developed by Alcoa to remove impure iron elements can reduce the w(Fe) of recycled 3××× and 4××× aluminum alloys from 0.57% to about 0.13% when combined with Mn and Si fluxes, and is suitable for industrial applications.

Electronics Industry

Application Background:

A large amount of scrap aluminum is generated during the electronics manufacturing process, and this scrap aluminum needs to be recycled efficiently to reduce production costs and environmental impact.

The application of double-chamber furnaces in the electronics industry can significantly improve the recovery rate and quality of scrap aluminum.

Specific application:

Double-chamber furnaces are used to process scrap aluminum in electronics manufacturing, such as housings, radiators, etc.

Through preheating and immersion melting, the recovery rate of scrap aluminum is significantly improved and the burn-off rate is greatly reduced.

For example, Samsung has increased the use of recycled plastics to more than 20% by optimizing the recycling process, and applied double-chamber furnace technology in scrap aluminum recycling, which has significantly improved the recovery rate and quality of scrap aluminum.

5. Market Trends of double-Chamber Furnace Melting Technology

5.1 Market Demand Growth

Environmental Protection Policy Promotion:

With the increase of global environmental awareness, governments of various countries have introduced strict environmental protection policies to promote the development of the recycled aluminum industry.

As a highly efficient scrap aluminum melting equipment, the dual-chamber furnace can significantly reduce energy consumption and emissions, meet environmental protection requirements, and market demand continues to grow.

Resource Shortage:

Primary aluminum resources are gradually in short supply, and recycled aluminum has become an important alternative resource.

The dual-chamber furnace can improve the recovery rate and quality of scrap aluminum, meet the market demand for high-quality aluminum alloys, and market demand continues to increase.

Cost Advantage:

The dual-chamber furnace significantly reduces energy consumption and burnout by optimizing the preheating and melting process, improves metal recovery rate, and reduces production costs.

This makes the dual-chamber furnace increasingly competitive in the market.

5.2 Technology Development Trends

Automation and Intelligence:

The automation and intelligence level of the double-chamber furnace is constantly improving.

By installing advanced control systems, precise control and automated operation of the smelting process can be achieved.

For example, the temperature automatic control system, the composition automatic control system, the pouring automatic control system, etc., have improved production efficiency and product quality stability.

High efficiency and energy saving:

The thermal efficiency of the double-chamber furnace is constantly improving.

By adopting regenerative combustion technology, electromagnetic pump technology, etc., the energy utilization rate is significantly improved and energy consumption is reduced.

For example, the thermal efficiency of the regenerative double-chamber aluminum melting furnace is generally around 80%-90%, which is 30%-40% higher than that of the traditional single-chamber furnace.

Low emissions:

The emission control technology of the double-chamber furnace is constantly improving.

By adopting baghouse dust collector, activated carbon adsorption, desulfurization and denitrification technologies, the emission of black smoke and harmful gases is significantly reduced, meeting strict environmental protection standards.

February 5, 2025