HSSP is a flexible batch sterilization process based on the Nauta® conical dryer design. It is especially suitable for the heat treatment of products like herbs, spices and teas.
The working principle of HSSP involves six steps before a product is sterilized. Raw material in big bags or sacs is unloaded manually in the Nauta sterilizer (step 1). All next steps of the HSSP process are fully automated. A recipe is selected on the control cabinet and soon after the treatment process is started. The sterilizer is put under vacuum, heat is added to the product via the wall of the sterilizer and the mixture is homogenized. Steam is injected for a very short moment to minimize the quality losses.
Next step is the post-drying step, in which the condensed water is evaporated at vacuum conditions. A cooling water condenser is trapping the evaporated water vapours and ethereal oil losses. The moisture level of the sterilized product sets the duration of the post drying step. In step 5, the product is cooled under atmospheric conditions. During this phase it is possible to reintroduce some oils to the product. The product is ready for discharge from the Nauta sterilizer. During discharge any lumps in powdery products are removed before bagging or loading in a container.