LORDERAN 100L/150L Food Steam Autoclave with Air Compressor, Counter-Pressure Food Sterilizer for Retort Pouches, Cans, Jars

A Reverse Pressure High-temperature Sterilizer (also known as a Counter Pressure Sterilizer or a type of retort sterilizer) is an apparatus primarily used in the food packaging and related industries to sterilize products packaged in flexible or sealed containers like pouches, plastic trays, or bottles. It uses a combination of high-temperature saturated steam and a controlled amount of "reverse pressure" (or "counter-pressure") to ensure sterilization while preventing the packaging from being damaged. How it Works The operation of a reverse pressure sterilizer involves the standard process of steam sterilization combined with a balancing pressure mechanism. High-Temperature Sterilization: Similar to a traditional autoclave, the unit heats the contents (packaged products) using saturated steam to high temperatures, typically between 115°C and 135°C to kill microorganisms. Internal Pressure Build-up: During the heating and sterilization phase, the temperature inside the sealed packaging (like a food pouch) rises, causing the internal pressure to increase. Applying Reverse Pressure: To prevent this internal pressure from causing the flexible packaging to swell, deform, or even rupture, a controlled external pressure—the reverse pressure—is introduced into the sterilization chamber. This is typically accomplished by injecting compressed air or steam. The external pressure is maintained to be slightly higher than or equal to the internal pressure of the product package. Cooling Phase Protection: During the rapid cooling process after sterilization, the steam inside the chamber condenses, causing the external pressure to drop quickly. However, the contents inside the packaging remain hot for a period, maintaining a relatively high internal pressure. The reverse pressure must be continuously applied during this cooling phase to prevent the packaging from being damaged or collapsing due to the resulting pressure differential. This pressure control ensures the packaging's integrity, which is crucial for product safety and shelf life.