Power-Variable Ultrasonic Freezing of Salt-Water Fish Fillets

The patent applies dynamic adjustment of ultrasonic power during the freezing process. The ultrasonic power is varied in multiple stages: initially set at a first power level to promote nucleation, then adjusted to a second power level to control crystal growth, and finally adjusted to a third power level to break down large crystals. This dynamic power adjustment resolves the contradiction by enabling both rapid freezing and uniform ice crystal formation throughout the process.

The patent employs periodic ultrasonic treatment with distinct phases. The ultrasonic waves are applied in periodic cycles with different power levels at different stages of freezing. This periodic action allows the system to promote nucleation during certain phases while controlling crystal growth during other phases, achieving both short freezing time and uniform ice crystal size.

The patent dynamically adjusts ultrasonic power levels based on the freezing stage. Instead of continuous high-power application, the system uses a first lower power level for initial nucleation promotion, then adjusts to different power levels at subsequent stages. This dynamic approach maintains reliable nucleation promotion while significantly reducing overall energy consumption compared to continuous high-power treatment.

The patent applies ultrasonic waves at different power levels appropriate to each freezing stage rather than using excessive high power throughout. The first power level is sufficient for nucleation promotion, and subsequent adjustments prevent excessive energy input that would cause tissue damage. This partial action principle optimizes energy efficiency while maintaining treatment effectiveness.