There are more than 60,000 industrial kilns in use in China, which consume more than 100 million tons of standard coal per year. The fuels used are coal, oil, gas, and electricity. Most of them are coal, including coal-based gas. The main industries are steel and non-ferrous metals. , Building materials, machine manufacturing, chemical industry, light industry, food and military industry, etc. Three demonstration EMC projects implemented nearly 100 various industrial furnaces, including metallurgical electric arc furnaces, ladle refining furnaces, steel rolling furnaces, heat treatment furnaces, sintering furnaces, submerged arc furnaces, sintering kilns, and glass melting furnaces. Kilns, ceramic roasting kilns and cement rotary kilns are mainly distributed in steel, nonferrous metals, building materials, light industry and machine manufacturing enterprises. There are still many kinds of industrial kilns energy-saving transformation demonstration EMC has not yet been involved. There are many energy-saving transformations of industrial kilns, mainly including heat source transformation, combustion system transformation, kiln structure transformation, kiln insulation transformation, flue gas waste heat recovery and utilization, and control system energy-saving transformation.
①Renovation of heat source
The content of the heat source transformation varies depending on the type of kiln. For kilns that use electricity as the heat source, according to the product process requirements, some are to change the industrial frequency power supply to a low-frequency power supply, and some are to change the AC power supply to a DC power supply. Electricity-saving transformation, automatic control transformation of electrodes, etc.; some kilns are changed from oil to use various recovered combustible gas, and some are changed from oil and gas to electric heating, all in order to reduce energy consumption.
②Renovation of combustion system
For oil-fired and gas-fired kilns, the combustion system transformation is mainly to replace old burners with new burners, and some recover flue gas waste heat to preheat the combustion air; for coal-fired kilns, this transformation is to transform the original coal seam combustion into Suspended combustion of pulverized coal to increase the combustion rate of coal.
③Renovation of kiln structure
The structure of industrial kilns varies according to different industries and processes, and there are many types, such as smelting, melting, sintering, heat treatment, heating and other kilns in steel and nonferrous industries, and those in building materials, light industry, chemical industry, machine manufacturing, food and other industries. Kilns for roasting, calcination, melting, heat treatment, reaction drying, baking, etc. With the advancement of science and technology, the implementation of energy-saving and environmental protection policies and the development of market competition, the structure of industrial kilns is continuously improved and optimized. Its main purpose is to improve the combustion status, reduce the heat dissipation area, and increase the effective volume of the kiln. The effect of structural transformation can not only reduce energy consumption, but also improve product quality and increase output. The transformation of kiln structure, especially for large-to-small projects, must be distinguished, that is, the energy-saving benefit of the transformation project is greater than other benefits such as increased production before it can be recognized as an energy-saving transformation project.
④Kiln insulation transformation
Most of the industrial kilns operate above 1000°C, and the lower ones are hundreds of degrees Celsius, so the insulation status of the kiln is directly related to its energy consumption. Replacing or improving the insulation condition of the kiln with new-type insulation materials can directly reduce fuel consumption and improve the working environment.
⑤Modification of control system
Transform manual control or semi-automatic control into automatic control. According to the product process requirements, comprehensively adjust the feed volume, fuel supply volume, air intake and induced air volume, and finished product output from the kiln (furnace), so that the kiln is running in a good state and can be obtained. Good energy saving effect.
The various energy-saving renovation measures of industrial kilns save coal and petroleum resources, which can obtain a good reduction effect of greenhouse gas CO2, which is beneficial to alleviate global warming, and can also reduce acid rain gas SO2 and NOX and total suspended particulate matter The emission of ions is conducive to improving the ecological environment of the region.