Ultrasonic Spray Granulation Technology

Ultrasonic spray granulation technology is an advanced process that combines ultrasonic atomization technology with spray drying technology to prepare micron or submicron spherical particles. It is particularly suitable for preparing high-purity and well homogeneous fine powders.

What is ultrasonic spray granulation?
In brief, ultrasonic spray granulation is a process that uses high-frequency ultrasonic energy to break liquid (solution, suspension or lotion) into extremely fine droplets, and then rapidly crystallizes or dries the solute or solid in the droplets through heating and drying to form fine, uniform spherical particles.

Its core is to replace the nozzle of traditional pressure or centrifugal spray dryer with ultrasonic atomizer.

Working principle and process

This process mainly consists of two key steps:

1. Ultrasonic Atomization

Core component: Ultrasonic atomizer, usually a piezoelectric ceramic transducer.
Working principle: High frequency electrical signals (usually 20kHz -3MHz) are applied to piezoelectric transducers to generate high-frequency mechanical vibrations of the same frequency.
Formation of capillary waves: This vibration is transmitted to the free surface of the liquid, forming a special type of ‘capillary wave’.
Droplet generation: When the vibration energy exceeds the limit that can be maintained by the surface tension of the liquid, a large number of extremely small and uniform droplets will splash out at the peak of the capillary wave, forming aerosol mist. The key point is that the size of droplets is mainly determined by the frequency of ultrasonic waves. The higher the frequency, the smaller and more uniform the droplets produced, and it is not related to the flow rate and pressure of the liquid.

2. Drying and solidification

The fine mist droplets generated are carried into a heated drying tower by carrier gases such as nitrogen and air.
In high temperature environments, the solvent (usually water or organic solvents) in the droplets is instantly evaporated.
For solutions, solutes rapidly supersaturate and precipitate crystals, forming solid particles.
For suspension or lotion, the solid particles are dried and agglomerated into balls.
Finally, the dried particles are separated from the airflow (through cyclone separators, bag filters, etc.) to collect the dried powder.

Main technical features and advantages

Compared with traditional spray granulation, ultrasonic spray granulation has significant advantages:

Uniform particle size and good monodispersity are its most prominent advantages. Due to the precise control of droplet size by ultrasonic frequency, the generated particles have a very narrow particle size distribution and high sphericity.
Small and controllable particle size: By changing the ultrasonic frequency, particles ranging from submicron (>0.5 µ m) to tens of microns (~50 µ m) can be produced, which is very suitable for preparing ultrafine powders.
No clogging problem: Ultrasonic atomizers do not have nozzles with small apertures, making them very suitable for handling suspensions or high viscosity liquids containing particles, avoiding the problem of traditional nozzles being prone to clogging.
Low energy consumption and low flow rate: The atomization process has high energy efficiency and can handle very low liquid feed rates (as low as milliliters per hour), making it very suitable for laboratory research and expensive material processing.
High purity: The process does not require compressed air (to avoid oil pollution), and the material only comes into contact with the inert atomization surface, ensuring the high purity of the product.
Simple and stable operation: parameters (frequency, temperature, gas flow rate) are easy to control and have good repeatability.

Main application areas

This technology is widely used in high-tech and high value-added fields:

Electronic ceramic materials: Preparation of dielectric powder, ferrite powder, fluorescent powder, etc. for MLCC (multilayer ceramic capacitors) requires uniform particles and high sphericity.
Catalyst: Prepare catalyst particles with high specific surface area and uniform distribution of active sites.
Pharmaceutical industry: Manufacturing microspheres of active pharmaceutical ingredients (APIs) for controlled release and inhalation administration (such as insulin dry powder inhalers).
New energy materials: Preparation of positive electrode materials (such as LiFePO ₄, NMC), negative electrode materials, solid electrolyte powders, etc. for lithium-ion batteries. Uniform particles help improve the consistency of battery performance.
Superconducting materials and metal powders: Prepare high-purity superconducting materials (such as YBa ₂ Cu ∝ O ₇₋ₓ) or metal powders through precursor solutions.
Research field: Used for the development and preparation of new materials and formulas in the laboratory.

Ultrasonic spray granulation is an accurate and efficient technology for the preparation of micro and nano particles. It uses the unique physical characteristics of ultrasonic wave to solve the bottleneck of traditional spray granulation in particle uniformity, fineness and handling of special materials, and has become one of the preferred technologies for research, development and production of high-end functional powder materials.

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.

Chinese Website: Cheersonic Provides Professional Coating Solutions