Retorting is oldest technology and has developed a lot in last century.
There are different types of retorting system
a. Steam Air Process
Temperature Come-up and Holding Time:
Steam is automatically & directly injected into the retort chamber and is properly distributed; a fan agitating air with efficiency enables to get a uniform steam/air distribution in the entire retort chamber in order to guarantee good temperature accuracy during the holding time.
- The cooling is obtained with recirculated water cooled by fresh water or via a Plate Heat Exchanger.
- Recirculated water comes from steam condensates to which is added an amount of pre-cooling water. The addition of cold water is automatically and gradually got in order to eliminate the "thermal shock" and control temperature for ramping down.
During all the Heat & Cooling steps, the electronic process controller monitors temperature and pressure inside the retort chamber. More information
B. FULL WATER IMMERSION / TECHNOLOGY
Temperature come-up and holding time steps
- A volume of preheated water at a pre-determined temperature is stored in a tank above the retort and is transferred into the treatment retort chamber (total immersion of the packaging)
- This amount of water is circulated by a pump and is heated by steam for maintaining a constant temperature during the desired treatment.
- Temperature control (steam injection in the exchanger) and pressure (injection or venting of compressed-air) are automatically and independently controlled, according to the programme settings of "Tables of set values".
A part of the hot water is put back into the tank (energy saving). The rest of the process water continues to be recirculated and is cooled through a heat exchanger.
During all the Heat & Cooling steps, the electronic process controller monitors temperature and pressure inside the retort chamber. More information.
C. Hot Water Spray / Technology
A low amount of water is kept in the bottom of the retort chamber. During all the process cycle (sterilisation & cooling) this amount of water is recirculated by a high flow rate pump and uniformly distributed with one inlet per basket. Heating and cooling of this water is made through a plate heat exchanger. A process controller actuates steam and water valves. During all the Heat & Cooling steps, the electronic process controller monitors temperature and pressure inside the retort chamber. More information
For Retort Pouch please read this article