The technical application process of pet freeze-drying machine is a precision machining process that combines low temperature, vacuum and sublimation principles, aiming to Retain the nutritional content and flavor of the raw materials while extending their shelf life. The following are the core technical steps and key points:

1. Pre freezing stage

Objective: To quickly freeze pet food ingredients (such as meat, fruits, vegetables, or seafood) below freezing point, allowing the internal moisture to form a stable ice crystal structure. Usually, freezing is achieved in an ultra-low temperature environment of -30 ℃ to -50 ℃.

Function: The low temperature at this stage can prevent cells from rupturing due to slow freezing, reduce damage to food tissue, and lay the foundation for subsequent sublimation dehydration. For example, the eutectic point of chicken nuggets is about -20 ℃, and the actual pre freezing temperature needs to be lower to ensure sufficient crystallization.

Equipment support: Cooling is achieved through the collaborative work of the compressor, condenser, and evaporator in the refrigeration system.

2. Vacuum sublimation drying (one-time drying)

• Environment construction: Transfer the pre frozen material into a high vacuum chamber, where the pressure drops below the triple point of water (about 610Pa), promoting the direct sublimation of ice crystals from solid to gaseous water vapor, skipping the liquid phase.

Temperature control strategy: Gradually increase the temperature to accelerate the sublimation rate, but strictly control it within the eutectic point to avoid material collapse or deformation. For example, the maximum drying temperature for meat needs to be dynamically adjusted based on its melting temperature.

Dehydration efficiency: It can remove 95% to 99% of water, significantly reduce weight and volume, while maintaining a porous sponge like structure for easy rehydration.

1. Analysis drying (secondary drying)

Deep removal of residual moisture: After one drying, maintain a moderate vacuum and fine tune the temperature to further remove free water molecules adsorbed on the surface of the material, ensuring that the final product has a moisture content of less than 5%.

Parameter optimization: Set the heating rate and duration based on the characteristics of different raw materials to prevent nutrient loss or shell coking and hardening caused by overheating.

2. Operation of Condensation Recovery System

• Water vapor treatment: The evaporated water vapor is cooled by a condenser and re liquefied into water before being discharged, which not only maintains the vacuum degree but also avoids the influence of moisture reflux on the drying effect. This closed-loop design improves energy efficiency and reduces pollution risks.

3. Full process intelligent control and monitoring

Automated management: relying on the PLC control system to adjust the temperature curve, vacuum degree, and time program in real time, ensuring that the parameters at each stage accurately match the material requirements. For example, large-scale industrial equipment can process 500-1000kg of raw materials in a single batch, balancing scalability and flexibility.

Quality assurance: By monitoring key indicators such as pressure fluctuations and temperature uniformity through sensors, process deviations can be corrected in a timely manner to ensure the color, shape, and nutritional stability of the finished product.

4. Post processing and packaging

• Form adaptation: Process freeze-dried products into granules, blocks, or powders according to market demand, such as single ingredient freeze-drying (chicken breast pellets), compound formula freeze-drying (beef+carrots), or functional additives (probiotic freeze-drying blocks).

• Fresh storage: Vacuum nitrogen filled packaging is used to isolate oxygen, allowing the product to be stored at room temperature for 12-24 months without the need for preservatives and easy to transport and carry.

In summary, pet freeze-drying technology achieves high nutrient conversion from raw materials to finished products through low-temperature freshness locking, vacuum dehydration, and intelligent temperature control. This process is not only suitable for the production of mainstream pet staple foods, but can also be extended to snacks, additives, and other fields to meet diverse feeding needs.