Silicon carbide nozzles are a new type of ceramic material characterized by high-temperature resistance, oxidation resistance, high strength, tolerance to extreme cold and heat, excellent thermal shock resistance, minimal high-temperature deformation, good thermal conductivity, wear resistance, and corrosion resistance. So, how much do you know about the structure of silicon carbide nozzles? Different structures of silicon carbide nozzles result in variations in processing efficiency and service life. A reasonable nozzle structure is essential for achieving high abrasive velocity, thereby improving processing efficiency and reducing costs. From the inception of nozzles until a long period afterward, cylindrical nozzle structures were predominantly used. To date, a variety of nozzle structures have been developed both domestically and internationally. 1. Cylindrical Straight-Hole Nozzle Structure Cylindrical straight-hole silicon carbide nozzles combine the functions of both a spray gun and a nozzle. They feature a simple structure and can be directly replaced with seamless steel tubes or obtained by drilling holes in materials. However, these nozzles have a relatively short service life and are mostly used in applications where sandblasting requirements are not stringent. 2. Tapered Nozzle Structure This nozzle structure includes a conical inlet for flow guidance and a straight section for focusing. Abrasives enter the nozzle more easily, and the distribution of abrasives across the nozzle cross-section is more uniform compared to cylindrical nozzles. 3. Venturi Nozzle Structure The Venturi nozzle structure consists of a Venturi-shaped throat and a slightly conical outlet with a slightly larger diameter. The airflow reaches sonic speed in the throat section and can achieve supersonic speeds exceeding 355 m/s at the nozzle outlet (whereas the exit velocity of abrasives in typical cylindrical straight-hole nozzles is low, only around 97 m/s). This type of nozzle is primarily used to achieve very high abrasive velocities, improving cleaning efficiency by 15%–25% compared to ordinary nozzles. To prevent rapid wear, the nozzle liner can be made of hard alloy or ceramic materials. To avoid clogging, the nozzle diameter should be 3–4 times the abrasive particle size. 4. Special Nozzles Special sandblasting nozzles have complex structures and are generally used in specific applications, such as sandblasting the inner walls of pipelines. 5. Combined Nozzle Structure This design involves using materials with different properties at the nozzle inlet, outlet, and middle section, which are mechanically assembled to form the nozzle. The inlet and outlet parts are typically made of high-hardness ceramics or other wear-resistant materials, while the middle section can be designed with high-toughness metals or other materials. Combined nozzles meet the varying requirements for erosion and wear resistance at different sections of the nozzle, thereby enhancing its overall erosion and wear resistance to some extent. However, compared to monolithic nozzles, they require the preparation of two or more materials and involve additional processes such as assembly.