What is Spray Pyrolysis
Principle of spray pyrolysis equipment
1. The spray process spray pyrolysis equipment first involves transforming the liquid precursor solution into tiny droplets through the spray device. This process utilizes pressure, ultrasonic vibration, or other physical means. For example, in the pressure spray, the solution passes through the special nozzle under the action of high pressure to form atomized droplets. The size and distribution of droplets are crucial for the subsequent thermal decomposition process, and smaller and uniformly distributed droplets can ensure more uniform thermal decomposition and product formation.
2. The droplets generated by the principle of thermal cracking then enter the high-temperature reaction zone. In this region, droplets rapidly evaporate solvents at high temperatures (usually ranging from several hundred to thousands of degrees), and precursor molecules undergo thermal decomposition reactions. Thermal decomposition reaction is based on the breaking and recombination of chemical bonds, which decompose the organic or inorganic components in the precursor into the target product. For example, in the preparation of metal oxide nanoparticles, the metal salt precursor decomposes at high temperatures, releasing metal oxides and gas by-products. Gas by-products will be discharged from the reaction zone, while metal oxides gradually form the desired nanoparticles or other forms of products.
Structure of spray pyrolysis equipment
Spray system
1. Type of nozzle: Pressure nozzle: By applying high pressure, the solution forms droplets through small nozzles. The nozzle can produce relatively uniform spray and is suitable for solutions with low viscosity. For example, in some processes of preparing ceramic powders, a pressure nozzle is used to spray a solution containing ceramic precursors into the pyrolysis zone.
- Ultrasonic nozzle: Using the vibration of ultrasonic waves to form tiny droplets of solution on the surface of the nozzle. The advantage of the ultrasonic nozzle is that it can produce smaller droplets, and it can also spray highly viscous solutions. Ultrasonic nozzles are a good choice for preparing nanomaterials, especially when small and uniform particle size is required.
2. The solution supply device includes components such as storage tanks, conveying pipelines, and pumps. The storage tank is used to store precursor solutions, and its material should be selected according to the chemical properties of the solution to prevent chemical reactions between the solution and the container. The conveying pipeline should ensure that the solution can be stably delivered to the nozzle, and the parameters such as the inner diameter and length of the pipeline will affect the flow rate and pressure of the solution. The pump is used to provide power so that the solution can reach the nozzle at a proper flow rate. The flow and pressure control accuracy of the pump have an important impact on the quality of spray.
Reactor furnace
1. Heating method: Resistance heating: This is one of the most common heating methods. By passing current through the heating elements (such as heating wires) of the reactor, heat is generated. The advantage of resistance heating is that temperature control is relatively simple and stable, and it can provide a relatively uniform temperature distribution. For example, in some small spray pyrolysis equipment, resistance heating is often used in the reactor used to prepare metal nanoparticles.
- Induction heating: Using the principle of electromagnetic induction, when an alternating magnetic field passes through metal components (such as graphite crucibles) in a reaction furnace, induced currents are generated in these components, which in turn generate heat. The characteristic of induction heating is its fast heating speed, which can reach high temperatures in a short period of time, making it suitable for reaction processes that require high heating speed.
2. The temperature monitoring and control system is equipped with temperature sensors inside the reactor, such as thermocouples or thermal resistors, for real-time monitoring of the temperature inside the furnace. These temperature data will be fed back to the control system, which adjusts the heating power according to the preset temperature curve to ensure that the temperature inside the reactor remains within the required range. For example, precise temperature control has a critical impact on the performance and quality of semiconductor materials during their preparation process.
Product collection system
1. The filtering device is used to collect solid products and separate them from gases. Filtering devices typically include ceramic filters, metal filters, or fiber filters. In the process of spray pyrolysis, the solid products (such as nanoparticles, powders, etc.) generated will be intercepted by the filter, and the gas by-products will be discharged through the filter. For example, in the process of preparing nano titanium dioxide, ceramic filters can effectively collect titanium dioxide nanoparticles.
2. The gas processing unit processes the discharged gas by-products. These gases may contain toxic and harmful substances or valuable chemicals. For example, in some precursor decomposition processes, acidic gases are generated and need to be treated through alkaline absorption towers to avoid environmental pollution. Meanwhile, if the gas contains valuable components such as organic volatiles, they can be recovered through condensation, adsorption, and other methods.
About Cheersonic
Cheersonic is the leading developer and manufacturer of ultrasonic coating systems for applying precise, thin film coatings to protect, strengthen or smooth surfaces on parts and components for the microelectronics/electronics, alternative energy, medical and industrial markets, including specialized glass applications in construction and automotive.
Our coating solutions are environmentally-friendly, efficient and highly reliable, and enable dramatic reductions in overspray, savings in raw material, water and energy usage and provide improved process repeatability, transfer efficiency, high uniformity and reduced emissions.
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