Is dry ice used for dust removal in heat exchangers?

Yes, it works well. Specifically, it utilizes the “explosive force” generated by the rapid vaporization of CO2 to shake the ash off the furnace tubes. When cleaning with ice, it is usually necessary to keep the exhaust fan running at full capacity, so that the dust removed can be sucked away at any time

What was said upstairs is quite right – the rapid expansion of dry ice can be used to shake the dust down, but a fan needs to be turned on to remove it quickly. The specific manufacturing process can be found online

I. Principle of dry ice cleaning 1. Impact force. Dry ice impacts the surface to be cleaned at high speed; the dissipation of the impact kinetic energy, along with the extremely rapid heat transfer between the dry ice particles and the cleaning surface, causes carbon dioxide to transition from a solid state to a gaseous state in an instant. 2. “Micro-explosion”. When the dry ice particles penetrate the cracks in the dirt, they vaporize in a fraction of a second; their volume expands by nearly 800 times instantly, thereby lifting the dirt away from the surface of the object. 3. “Cracking”. For two different materials with distinct coefficients of thermal expansion, a temperature difference between them will disrupt the bond between the two materials. Dry ice particles have an extremely low temperature of -78.5°C; when they impact the surface of the material to be treated, they freeze the dirt until it becomes brittle and cracks, resulting in \"cracking\" or thermal shock effects that affect the mechanical properties of the dirt adhering to that surface. In the dry ice cleaning process, compressed air is used as a power source to propel dry ice particles at the surface of the item to be cleaned. However, achieving a clean result relies not solely on high wind pressure, but rather on the low temperature of dry ice. Therefore, when cleaning electronic devices, it is sufficient to reduce the wind pressure so as not to damage the structure of the devices ； When cleaning stubborn stains, we can also increase the air pressure and combine it with the cooling effect of dry ice to achieve a dual-pronged approach. II. Advantages of dry ice cleaning 1. Wide range of applications: It can quickly remove oil stains, paint, ink, adhesives, carbon deposits, asphalt, scale, rust, mold release agents, polyvinyl chloride resin, etc. It enables contactless cleaning of small holes, uneven surfaces, and edges. 2. Cost-effective: Fast cleaning with optimal results, improving production efficiency and product quality ； It can be cleaned online without shutting down operations, thereby increasing production capacity ； It does not damage the surface of the item being cleaned, thereby extending its service life ； Online cleaning also prevents accidental damage during the process of disassembling and assembling the object to be cleaned ； No residues remain, avoiding environmental pollution caused by other cleaning processes as well as the costs associated with dealing with such pollution. 3. Safe and environmentally friendly: CO2 is non-toxic and meets the safety and environmental standards set by USDA, FDA, and EPA ； No secondary pollution during the cleaning process ； Compliant with China’s relevant laws and regulations on clean production ； Replace toxic chemicals in cleaning processes to fundamentally prevent harm to the human body ； High operational safety ； It has the effect of low-temperature sterilization in the food and pharmaceutical industries. 4. Simple to use – utilizes on-site compressed air, making it convenient and practical ； Easy to operate. III. Examples of dry ice cleaning in the chemical industry: rapid cleaning of polyvinyl chloride resin from heat exchangers ； Effectively removes rust, hydrocarbons, and other surface contaminants from various pressure vessels such as compressors, storage tanks, and boilers ； Clean the reaction vessel and condenser ； Decontamination of complex machinery. Cleaning industrial facilities such as industrial boilers and heat exchangers can save a significant amount of energy. According to statistics, when scaling on heat exchange equipment reaches 5 millimeters, fuel losses are estimated to be around 10%. Based on China’s energy-saving targets during the \"Eighth Five-Year Plan\" period, which were 100–200 million tons of standard coal, the energy saved merely by cleaning boilers alone would already meet these requirements. On the contrary, industrial equipment suffers significant harm due to the lack of cleaning. In industrial equipment, corrosion of heat exchangers, coolers, and similar components is extremely severe; in the petrochemical industry, corrosion has become one of the main reasons for production shutdowns. A vinyl acetate plant with an annual production capacity of 300,000 tons loses 7.5 million yuan per day of shutdown. Thoroughly removing dirt through chemical or physical cleaning not only contributes to safe production but also helps to improve the production environment and extend the service life of equipment, which highlights the importance of cleaning tasks. It is reported that the Shuguang Oil Production Plant of CNPC’s Liaohe Oilfield Branch has actively adopted dry ice jet cleaning technology to clean boilers, achieving good results. This approach not only reduced the flue gas temperature but also proved effective in removing stubborn deposits from the boiler’s finned tubes. At the same time, it also provides some protection for the boiler’s insulation layer, extending the service life of the convection section and **improving the boiler’s thermal efficiency. Results of on-site tests showed that the flue gas temperature dropped from 275 degrees Celsius to 195 degrees Celsius, the furnace pressure decreased from 1.5 kPa to 0.65 kPa, and the fuel consumption per cubic meter fell from 64 kilograms to 59 kilograms, resulting in savings of over 400,000 yuan.