Operating Instructions for Retorts for Canned Food

**Horizontal Retort Sterilization Process for Canned Food**

Horizontal retorts are commonly used in canned food factories for normal-pressure boiling sterilization. These retorts use compressed air to achieve back-pressure sterilization, ensuring the integrity of the cans during the process.

### **Key Features of the Process:**

1. **Back-Pressure Sterilization:**

- Compressed air is introduced into the retort after the sterilization temperature is reached.

- This increases the internal pressure to 0.5–0.8 atmospheres, preventing can bulging and lid popping, especially for products like canned meat that require higher sterilization temperatures.

2. **Cooling Process:**

- After sterilization, steam supply is stopped, and cooling water is circulated through spray pipes to reduce the temperature.

- Compressed air compensates for the pressure drop caused by steam condensation during cooling.

3. **Venting:**

- Initial venting is performed to allow steam circulation.

- Additional venting every 15–20 minutes promotes effective heat exchange during sterilization.

### **Operational Notes:**

- **Sterilization Conditions:** The sterilization temperature, pressure, and time are strictly defined by the product's sterilization process to ensure safety and quality.

- **Compressed Air Usage:** Compressed air is not introduced during the heating phase but only after reaching the sterilization temperature to avoid heat transfer inefficiencies.

This method ensures effective sterilization while maintaining the structural integrity of the canned products.