Breakthrough in environmental protection equipment

2022-08-17
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Breakthrough in environmental protection equipment for drying furnace exhaust gas purification

since the promulgation of the Cleaner Production Promotion Law of the people's Republic of China, our barrel industry should implement cleaner production according to law, improve resource utilization, reduce and avoid pollutants, but the price is also much higher than ordinary production. Protecting and improving the environment is urgent, and the situation is grim. On the one hand, the state is strengthening the implementation of environmental protection laws and regulations. On the other hand, many of our barrel manufacturing enterprises do produce waste gas in production, which has not been effectively purified and treated

under the current conditions, it is a better solution for barrel making enterprises to install waste gas purification and environmental protection equipment in the drying room. However, many enterprises have various doubts and views because they need to consume more energy and the product efficiency of some manufacturers has yet to be confirmed

recently, Shanghai Qiaosheng electromechanical complete equipment Co., Ltd. has made a major breakthrough in this field. Its wrf-ii combustion catalytic environmental protection furnace has been widely recognized for its environmental protection and energy-saving effects after it was used in Shanghai Gaoqiao barrel making enterprises. Experts believe that the equipment can achieve the dual effects of environmental protection and energy saving, which is the most ideal and successful example of waste gas purification and environmental protection equipment (as shown in the figure, it is the process schematic diagram of the equipment). Since then, there has been an upsurge of waste gas treatment in the domestic barrel industry

now, I'd like to briefly introduce the use of waste gas purification and environmental protection equipment at home and abroad in recent years. Before that, I will first introduce the technical goal of 4+1 waste gas purification and environmental protection equipment proposed by Mr. Yin Yiguo, a metal packaging expert who has conducted in-depth research in this field

I. requirements for waste gas purification and environmental protection equipment 4+1

4+1 refers to four requirements and one benefit, and its specific content is four requirements:

1. The exhaust gas purification effect should reach the QB national environmental protection standard under the condition of smokeless and tasteless

2. The heat emitted by waste gas purification and environmental protection equipment should be recycled and fully utilized

3. The heat emitted by environmental protection equipment should be controllable when the coating drying room is used, and the general accuracy is 3 ℃

4. Do not affect product quality

one advantage:

the operating system of waste gas treatment environmental protection equipment and the operating system of drying room are independent and can be controlled mutually, which is conducive to the normal operation of production scheduling and drying room

II. Introduction to the types and principles of waste gas purification and environmental protection equipment

the effective method of purifying waste gas in the metal packaging industry at home and abroad is combustion method. There are flame combustion (direct combustion), thermal combustion, catalytic combustion and other types. Due to the low concentration of paint waste gas in the barrel making industry, it does not have the ability to make its own fuel purification. Therefore, only the latter two combustion methods are generally used

thermal combustion (also known as incineration method)

depends on the heat generated by the combustion of auxiliary fuel (burner) to improve the temperature of exhaust gas and oxidize the components containing hydrocarbons in exhaust gas. Decomposition into harmless carbon dioxide and steam. For the barrel industry, in order to achieve the ideal purification effect, it is necessary to design an incinerator that meets the capacity of the drying room, the baking process and the circulating air volume, that is, to achieve the three T conditions of heat: the reaction temperature in the furnace is about 760 ℃, the residence time of waste gas at this temperature, and the good mixing of waste gas and oxygen, In order to fully purify the exhaust gas

therefore, for drying rooms of different specifications and different paint varieties, there should be a reasonable plan. Although thermal combustion is the most thorough method to purify waste gas, it is necessary to recycle heat to purify waste gas at a high temperature of 760 ℃ in order to realize the practicality and economy of environmental protection equipment

catalytic combustion method

uses the catalyst in the combustion of exhaust gas to accelerate the reaction speed of exhaust gas decomposition, so that when the exhaust gas passes through the catalyst layer, it only needs 250 ~ 400 ℃ to purify the exhaust gas, which has obvious economy. Therefore, the design of catalytic combustion method must aim at different drying rooms and coatings to make the accuracy of high-efficiency catalytic experiment results difficult to ensure that the variety and dosage of the agent are compatible with the exhaust gas concentration of the air volume in the catalytic chamber, so as to fully purify the exhaust gas

general catalyst composition is divided into three parts: active component, cocatalyst and carrier. The active component is the main body of the catalyst, without which the catalytic reaction cannot be completed. The most ideal active component is platinum, palladium and other precious metals, and then nickel, cobalt and other transition non precious metals. They have long service life, high activity, and do not have the required activity when the cocatalyst exists alone. However, when it coexists with the former, it can improve the activity of active components. The carrier plays a supporting role for the above catalyst, so that the catalyst has a suitable shape and particle size, has a large specific surface area, is conducive to reaction, heat transfer and dilution, and extends the service life of the catalyst. The carrier can be sheet, honeycomb, granular, columnar, etc

therefore, the selection and arrangement of catalysts are very important, but in the process of purifying exhaust gas, the activity of catalysts always decreases gradually with the passage of time, that is, what we call catalyst aging or poisoning, because long-term use of catalysts at high temperature will cause crystal growth, fusion phenomenon to occur, and the decline of specific surface area will eventually fail. Therefore, using this method to melt exhaust gas, Therefore, China has become one of the most important markets in the world. It is necessary to replace the catalyst

III. comparison between combustion method and catalytic combustion method

these two methods are the most concerned and widely used methods at home and abroad

incineration method: with simple structure and convenient management, it is the most thorough method to purify waste gas, which is widely used at home and abroad. However, since this method purifies waste gas at a high temperature of 750 ~ 800 ℃, the addition and utilization of heat is the key technology, otherwise, it will lose practical value. At present, domestic incinerators have been able to recycle heat for production to achieve the purpose of full utilization

catalytic combustion method: through the catalytic layer, the purification temperature of waste gas can be only 250 ~ 400 ℃, which is more energy-saving than incineration method. However, if heat recovery is not carried out, the injection pressure of the catalyst will not affect the energy consumption of the 1 sampling furnace, which will certainly increase the production cost of the barrel factory. At present, domestic catalytic environmental protection furnaces can fully recover heat, which is a gratifying phenomenon. If the service life of the catalyst can be extended to more than two years, it will be more practical. In addition, strengthening the management of the catalytic environmental protection furnace and avoiding the catalyst from contacting sulfur, iron and other substances are important measures to prolong the service life of the catalyst

the above two combustion methods have one thing in common, which is to make full use of the heat generated by the oxidation and decomposition of exhaust gas to provide the temperature needs of the combustion chamber

therefore, a higher concentration of exhaust gas is conducive to saving energy consumption

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