1) Sterilisation cycle.
Based on the soft-packed beetroot sterilisation cycles (whole raw beetroot, 55-65 mm bag thickness) used by Steriflow customers, the full cycle time is about 70-75 minutes, of which 30-35 minutes is holding time (121C). Heating from 20C to 121C takes 10 minutes. Cooling to 30C takes 20 minutes.
2) Heating.
The speed of product heating depends primarily on the product itself, on its consistency. Therefore, it is illogical to claim that a technology heats a product faster simply without specifying the product. Saturated steam does carry more heat energy than water. But the basic fact is that steam autoclaves do not work on pure steam, but on a steam-air mixture. Air is needed to create back pressure in the autoclave chamber. It is a great insulator and reduces the heating capabilities of the steam. A fan is used to mix both steam and air and to circulate them. For example, a steam-air mixture at 120°C and 2 bar yields about 4000 kcal/cm2, and a water cascade has about 9000 kcal/cm2.
The purge time of the steam autoclave should also be included in the heating time, i.e. the time when the air is expelled and the chamber is filled with the required amount of steam. During this time, the product is not heated, but these 3 minutes are an integral part of the cycle time.
3) Cooling.
Water cascade cooling is much more efficient because of the more powerful cooling water flow. The nozzles in a steam autoclave have a weak effect because they are a resistance area of their own. In Steriflow, the water flow is free through the distribution grid and is more powerful.
4) Other advantages
Other advantages of Steriflow are also worth noting:
- Full recovery of steam condensate due to the heat exchanger (not available with direct steam injection, everything is lost in the chamber)
- Possibility of partial autoclave loading, which gives flexibility and convenience in production modes (not possible with steam autoclaves due to strict positioning of the baskets to ensure uniform steam-air flow)
- There are other design features that we can talk about in more detail during the meeting.