Changing coal-fired boilers to coke oven gas
In the future, precious energy sources such as natural gas, oil and electricity will become scarcer and even gradually depleted. Both domestic and foreign results show that the use of recycled metals to replace primary metals is an effective measure and key way to save energy. In the metal recovery and smelting process, the quality of the combustion system is a key factor affecting the amount of energy consumption. In the current industrial production of aluminum processing and secondary aluminum, an air-fuel combustion system is generally used. Nowadays, the pressure of global competition is gradually increasing, requiring the reduction of greenhouse gas emissions, more frequent environmental inspections, and rising fuel prices have made the aluminum industry more and more concerned about improving energy efficiency and reducing production costs. Pure oxygen combustion technology is a new type of combustion technology developed under this background, which can well meet these needs of the aluminum industry. In the past few decades, Linde has upgraded hundreds of metal smelting and processing furnaces from air combustion to pure oxy-fuel combustion, so it has extensive experience in the application of oxygen to industrial furnaces. These rich experience in the optimization of the production process before and after the pure oxy-combustion transformation can avoid the costly risk of trial and error at the initial stage of the project transformation and ensure that the furnace can safely and smoothly switch from air combustion to pure oxy-fuel combustion. This article will describe the benefits brought by the application of oxy-fuel technology and the potential risks that may exist in oxy-fuel technology.
The combustion process of industrial furnaces is where a large amount of energy is consumed and the main pollutant emission source. Energy in the metal industry is mainly used for heating, melting, smelting and reheating the materials produced. At present, China's output of most metal products accounts for more than 50% of the world's total output, such as steel and aluminum alloys. More than two-thirds of steel output comes from Asia. In China, there are more than 120,000 industrial furnaces in operation. The energy consumption of these industrial furnaces accounts for more than 25% of China's total energy consumption and more than 60% of the energy consumption in the industrial sector. Iron and steel, non-ferrous metals and other industries are the main energy consumption and pollutant emitters.
The combustion process of industrial furnaces is where a large amount of energy is consumed and the main pollutant emission source. Energy in the metal industry is mainly used for heating, melting, smelting and reheating the materials produced. At present, China's output of most metal products accounts for more than 50% of the world's total output, such as steel and aluminum alloys. More than two-thirds of steel output comes from Asia. In China, there are more than 120,000 industrial furnaces in operation. The energy consumption of these industrial furnaces accounts for more than 25% of China's total energy consumption and more than 60% of the energy consumption in the industrial sector. Iron and steel, non-ferrous metals and other industries are the main energy consumption and pollutant emitters.
The combustion system is the core of the fossil fuel kiln. As a core component, the combustion system must match the furnace. The size and morphological characteristics of furnaces vary greatly. Commonly used furnace types in the recycled metal industry include rotary furnace and reverberatory furnace. The rotary furnace is cylindrical and can be designed as a tilting converter or a fixed-axis non-tilting converter. According to the design and installation position of the burner, the converter can be divided into single-channel and dual-channel converters, which respectively represent the path of combustion in the furnace from the start point (burner) to the end point (flue gas discharge position). The reverberatory furnace is a square furnace, and can also be designed as a tiltable and fixed reverberatory furnace. The reverberatory furnace can be a single-chamber furnace or a multi-chamber furnace. The melt can be moved or stationary. The process can be designed as continuous smelting or batch smelting.
There are also many ways to choose the combustion system of the furnace. The combustion system can choose air combustion, pure oxygen combustion technology or an air combustion-oxygen combustion hybrid system that combines the two technologies. Each type of combustion system has different combustion characteristics and will produce different combustion effects. In this article, we will compare and discuss the results of the long-term application of these several combustion technologies in aluminum processing and secondary aluminum smelting production processes in terms of process parameters, energy consumption and flue gas emissions.
Rotary furnace is suitable for fast melting of metal and slag. Rotary furnaces are generally not used for alloying or holding furnaces in the later stages of metal smelting. The raw materials of the rotary furnace are generally added by a special feeding car, and the goal of melting is as fast as possible; the furnace has been rotating during the production process, and the dust and smoke generated will be discharged from the furnace along with the high-temperature flue gas generated after combustion outer. The exhaust fan draws the flue gas out of the furnace or sucks it into the flue gas treatment system.
There are also many ways to choose the combustion system of the furnace. The combustion system can choose air combustion, pure oxygen combustion technology or an air combustion-oxygen combustion hybrid system that combines the two technologies. Each type of combustion system has different combustion characteristics and will produce different combustion effects. In this article, we will compare and discuss the results of the long-term application of these several combustion technologies in aluminum processing and secondary aluminum smelting production processes in terms of process parameters, energy consumption and flue gas emissions.
Rotary furnace is suitable for fast melting of metal and slag. Rotary furnaces are generally not used for alloying or holding furnaces in the later stages of metal smelting. The raw materials of the rotary furnace are generally added by a special feeding car, and the goal of melting is as fast as possible; the furnace has been rotating during the production process, and the dust and smoke generated will be discharged from the furnace along with the high-temperature flue gas generated after combustion outer. The exhaust fan draws the flue gas out of the furnace or sucks it into the flue gas treatment system.