Solutions for dust accumulation on fan impellers

Thread Content

This post was last edited by yuchenchf on 2017-7-29 at 10:56. Solutions for dust accumulation on fan impellers 【Keywords】: steel industry, fan impellers, polymer materials, dust prevention. I. Exhaust fans As a type of general-purpose mechanical equipment, exhaust fans are widely used in factories, mines, tunnels, cooling towers, vehicles, ships, and buildings for ventilation, dust removal, and cooling； Ventilation and exhaust for boilers and industrial furnaces ； Drying and sorting of grains ； Wind tunnel air supply, etc. As an important component in the operation of industrial equipment and crucial for ensuring the safe and continuous production of a company, any issue with fans can force production to come to a halt, which is absolutely unacceptable for businesses that rely on continuous production. Therefore, ensuring the integrity and safe operation of fan equipment has a significant impact on the operational efficiency and production efficiency of the entire system. This requires not only maintaining high standards in the manufacturing and installation of fans but also ensuring their proper use and maintenance. II. The main reasons for dust accumulation on the surface of the induced draft fan and on its impellers are that, as the exhaust gas flows past the impellers, a large amount of fine dust collides and deposits in the areas at the non-working front and rear edges of the blades, as well as near the rear edge of the working surface of the blades, close to the rear disk of the impeller. Additionally, the higher viscosity of the dust at high temperatures increases the likelihood of such deposition. Therefore, the temperature and humidity of the exhaust gas, as well as the impact velocity of the airflow, play a crucial role in the process of dust accumulation and crust formation. The inner surface of the impeller is also prone to dust accumulation. Since dust contains corrosive substances, severe corrosion often occurs beneath the accumulated dust. On the other hand, a corroded surface becomes very rough, allowing dust from the flue gas to easily adhere to it during operation, thus creating favorable conditions for further dust accumulation. Dust-resistant products are water-based, epoxy-silicone, low-surface-energy coatings that offer excellent demolding properties, as well as resistance to sliding and wear. They can adhere to various substrates, and the dust-resistant effect is achieved once the material has cured. (1) Equipment parameters: Material – carbon steel; Number of blades – 14; Diameter – 1600 mm; Rotational speed – 700 revolutions per minute; Medium – gas. (2) Problem analysis: The formation of dust accumulation on the fan impeller, as well as the strength of adhesion of this dust, are influenced by various factors, including the properties of the medium being transported, the concentration of dust and smoke, and the humidity of the medium. As the exhaust gas flows past the impeller, a large amount of fine dust collides and deposits in the areas of the non-working front and rear edges of the blades, as well as near the rear edge of the working surface of the blades, close to the rear disk of the impeller. Additionally, the higher temperature increases the stickiness of the dust, further increasing the likelihood of deposition. It is easy to see that the dust concentration and humidity of the conveying medium are key factors. 　(3) Traditional solutions: When the dust accumulation on the fan impeller reaches a certain level, it is necessary to clean off this dust. Common cleaning methods include manual mechanical cleaning and high-pressure water flushing. Regardless of the method used, most of them are merely temporary solutions that do not improve the accumulation of dust at all. III. Polymer Material Protection Law The dust-resistant coating for impellers is a water-based, epoxy-silicone, low-surface-energy coating that offers excellent demolding properties, as well as resistance to sliding and wear. It can adhere to various substrate materials, boasting superior overall performance. This makes it possible for companies to carry out cleaning tasks quickly and effectively. Using this technology for surface treatment represents an ideal solution to such problems, especially for fan impellers in the chemical and power industries, where it yields excellent results. Compared to traditional repair methods, the dust-resistant coating for impellers is easier to apply and requires less time; it **reduces the workload on workers and can be used over a long period of time – advantages that traditional repair methods cannot match. The use of this coating can also reduce equipment noise, extend the intervals between maintenance tasks, improve the overall efficiency of equipment use, and lower maintenance costs. IV. Application Process: 1) Surface treatment: Before applying this coating, the surface of the components must be treated, using sandblasting; the sandblasting grade should be SA2.5. 2) Surface cleaning: After sandblasting, the surface of the impeller should be rinsed with alcohol to ensure that there are no dust, grease, or other contaminants present. 3) Material spraying: This coating consists of two layers of water-based coatings, which are applied using a spray gun. First, apply the primer, with a coating thickness of 30-40μm. After two hours of curing, a non-stick coating is applied with a thickness of 40–80 μm; it can be used after 12 hours of curing (the curing time depends on room temperature, with higher temperatures resulting in faster curing). V. Application of image information