Application of dust removal technology in the renovation of power plant boilers

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This post was last edited by zhaolijun on 2015-6-6 at 16:37. In recent years, the rapid development of China’s economy has led to the prosperity of power enterprises. However, with the development of power companies, an increasing amount of boiler emissions have profoundly altered our atmospheric environment, leading to worsening air pollution. In today’s era of growing environmental awareness, installing boiler smoke and dust removal equipment has become a key measure and technological approach to reducing air pollution and emissions. Below is a brief introduction to the dust removal renovation technology for power plant boilers. In some more developed **, effective boiler dust removal technologies have been widely used to address air pollution, and their application is now quite mature. In our country, for various reasons, some advanced boiler dust removal technologies have not been properly promoted. With environmental pollution becoming increasingly severe, it is obvious that the promotion and application of these advanced technologies are imperative. 1. The main dust removal technologies for power plant boilers: At present, the dust removal technologies used in power plants in China are mainly divided into mechanical dust removal and electrostatic dust removal. The principle behind these methods is to use electricity or mechanical force to separate particles or dust from polluted gases, thereby achieving dust removal. However, there are mainly four types of dust removal technologies. In addition to the two mentioned above—mechanical dust removal and electrostatic dust removal—these also include filtration dust removal and wet dust removal technologies. The principle of dust filtration technology is to achieve dust removal through the filtering action of woven materials and filter layers. Within this field of dust filtration technology, it is mainly divided into particle filtration technology and bag filtration technology; among these two, bag filtration technology is being increasingly used for dust removal in power plant boilers, and this article will focus on explaining bag filtration technology. Another wet dust removal technique operates on the principle of using the cleaning effect of liquids to remove dust. This technique is not only highly effective at removing particulates from polluted gases but also helps to eliminate other harmful pollutants. The main types of wet dust removal techniques include venturi dust removal technology and low-energy washing technology. The above covers the boiler dust removal technologies used in major power plants and the relevant principles behind them. Clearly, many highly effective dust removal technologies have not yet been widely adopted in China. 2. The relevant principles and technical characteristics of bag dust removal technology: Among the various dust removal technologies used in power plant boilers, bag dust removal technology offers the most significant results and is also the most widely applied type of dust removal technology. Bag dust removal technology is a combination of filtration dust removal technology and electrostatic dust removal technology. In bag dust removal technology, the application of filtration-based dust removal methods relies on filter bags made up of filtering media or filter layers, which are used to filter out particulates and dust from polluted gases, thereby achieving dust removal. With continuous technological advancements, the materials available for filter bags are becoming increasingly diverse. The choice of filter bag material can be determined based on the characteristics of the power plant and its operational processes. Filter bags made of natural fibers or chemical fibers are widely used in dust removal systems for coal-fired boilers, while some power companies opt for metal fibers or glass fibers depending on their specific needs. Bag dust removal technology features high stability, low investment, simple technology, easy maintenance, and a high dust removal efficiency; therefore, it is widely used for dust removal throughout the entire production process. The application of bag filter technology in relation to electrostatic dust removal technology relies on high-voltage electricity generated by electric fields to filter out dust and pollutants present in polluted gases, thereby achieving dust removal. In electrostatic dust removal technology, pollutants collide with electric ions, and the resulting downward force causes the pollutants to aggregate and settle. Therefore, electrostatic dust removal technology can effectively filter out fine dust. The electrostatic dust removal technology is characterized by a high dust removal efficiency and a high degree of automation. However, its economic efficiency is low; therefore, when applying it, factors such as the actual production needs, energy consumption, and the production environment must be taken into account. In summary, bag filter technology, which combines filtration and dust removal techniques with electrostatic dust removal technology, is one of the good options for dust removal in power plant boilers. The fundamental principle of bag dust removal technology is to first utilize the principles of electrostatic dust removal: electric ions generated by the power plant collide with pollutants, causing them to settle, and then fine dust particles are collected and filtered through the filter bags, thereby achieving a very high dust removal efficiency. The combination of these two technologies can effectively reduce operating costs on a systematic basis; it enhances efficiency while simultaneously reducing pollution, making it an ideal dust removal technology for power plant boilers. It should be noted that bag filters also have their limitations in practical applications. The application of bag filters is susceptible to the influence of various factors, which are mainly reflected in two aspects. First, the corrosive substances present in the polluted gases can cause damage to the filter bags; therefore, when selecting the material for these bags, it is necessary to choose materials that are resistant to corrosion, high temperatures, and hydrolysis, in order to avoid increased maintenance and replacement costs in the future ； Secondly: Bag filters are prone to impurity condensation and filter layer clogging in conditions with high air humidity. Once this occurs, the particles that have already settled cannot fall properly, which affects the reliability of the equipment’s operation. Therefore, even though bag filter technology is one of the most effective techniques for dust removal in power plant boilers, there are still many areas that need improvement and enhancement. 3. Selection of bag dust removal equipment: When choosing bag dust removal technology, many factors need to be taken into consideration, such as the specific production capacity of the power plant, the type of boiler, and the production environment, among others. A thorough technical analysis is usually required before making a decision. At present, our country does not possess independent intellectual property rights for bag filters used in large-scale power plants. Our challenges lie in the short service life of the filter bags, the lack of reliability in the long-term operation of these bag filters, as well as high operational resistance and energy consumption of the systems. For the purpose of reducing operating resistance and ensuring the long-term reliability of dust collectors, a flow-balancing bag dust collector can be chosen. This type of dust collector is an improvement over conventional pulse bag filters; it uses a direct-in, direct-out airflow system, which effectively shortens the path that polluted gases take within the flue. The airflow is smooth and at a low speed, resulting in less resistance throughout the equipment’s structure. Additionally, this device includes a \"pressure stabilizing tank\" that is installed near the switching mechanism of the pulse valve. The pulse valve plays a key role in reducing operational resistance; it is used to release large amounts of compressed air in a short period of time. Therefore, when selecting a pulse valve, it is important to choose one with a simple structure, fast switching capability, and low resistance. A pressure stabilizing air tank with a large capacity can replenish air in a timely manner to facilitate the operation of the pulse valve. In addition, the air supply pipe should have a large diameter and low resistance. The requirements for the air storage tank are as follows: first, it must have sufficient capacity ； II. Stay as close as possible to the pressure stabilizing tank. The main components of this dust collector are: bag filters, necessary auxiliary equipment, and electrical and automation control systems. Some selective configurations will not be repeated here; power companies can choose those that suit their own needs. In summary, this bag filter offers excellent filtering performance, low operating resistance, reduced dust emissions, and improved reliability over the long term. Additionally, its simplicity of operation and ease of maintenance are also reasons why it achieves good results in practical applications. In short, it is a practical technology suitable for China’s specific conditions, and one that deserves to be promoted. Bag filters have strong adaptability, can remove a variety of pollutants, and do not cause secondary dust generation or fly ash, effectively preventing secondary pollution. Bag filters that combine two dust removal technologies reduce operating costs while achieving better dust removal results; moreover, such equipment offers advantages such as a small size, low energy consumption, and a relatively longer service life for the filter bags. In the areas that have undergone electrostatic treatment, the polluted gas is cooled, preventing the filter bags from coming into contact with hot polluted gas. This protects the filter bags, effectively extending their service life and improving the stability of the system’s operation. From an economic perspective, bag filter equipment requires a low initial investment, has low operating costs over time, and is easy to maintain with minimal expenses. Additionally, its excellent dust removal performance enables this technology to meet the increasingly stringent environmental requirements. In summary, bag filters, which are widely used, possess greater advantages over other technologies in boiler dust removal systems in power plants; they are technologies that should be widely promoted and represent a benefit to humanity. In practical applications, the technical staff at Weifang Tianjie actively explored various options and developed dust removal equipment tailored to the specific characteristics of the enterprise, achieving very good results. For example, some power plants emit various pollutants in the gases they produce; for instance, many boiler flue gases contain sulfur, and therefore the choice of dust collectors in such plants must take into account the need for sulfur removal. Many companies use waste ammonia water as a desulfurization agent; this not only helps to reduce operating costs but also saves them the expenses associated with treating waste ammonia water, achieving two goals at once and truly realizing the principle of using waste to deal with waste. These advanced technologies are worth learning from and promoting. Different dust removal technologies for power plant boilers have their own advantages and disadvantages, and the combination of various technologies also has its limitations. In practical applications, power companies should make appropriate choices based on their own circumstances, avoiding blindness; they can also innovate by flexibly selecting system configurations to develop dust removal equipment suited to their specific production needs. Additionally, when selecting dust removal equipment, economic efficiency and practical effectiveness should be taken into account. In an era of increasingly severe environmental pollution, power plants must assume their social responsibilities by taking active measures and employing technical solutions to treat the pollutants generated, and discharging them only after they meet the required standards. They must avoid short-sighted actions that prioritize their own immediate interests at the expense of the public’s interests. Finally, although there are many effective application technologies in boiler dust removal systems for power plants, they are not perfect; there is still much room for improvement in these technologies. In practical applications, power companies can make modifications as needed so that the dust removal systems better suit the company’s own development needs.