Steritherm DSI
Safeguard product taste, aroma, texture, appearance and nutrients with the Alfa Laval Steritherm DSI. This direct steam injection sterilizer protects the quality of dairy products, fresh beverages, and liquid foods. Continuous ultra-high-temperature (UHT) treatment rapidly heats products to sterilization temperatures for a short time, then quickly cools them before filling into aseptic packaging. It contributes to more production uptime, greater product integrity, and longer shelf life.
More uptime, enhanced product safety and longer shelf life with UHT treatment of dairy, food and beverage products
- Minimal thermal impact on heat-sensitive products due to rapid heating and cooling
- More uptime and lower maintenance costs due to direct steam injection and auto diagnostics supervision system
- Enhanced production safety due to verification of critical parameters by an automated FDA-approved recording device
- High energy efficiency and cost savings due to 100% use of the latent heat of steam
- Space-saving footprint that eliminates the need for condensate return systems
Increase product stability while retaining the natural, nutritional and organoleptic characteristics of dairy, food and beverage products. Sterilize heat-sensitive, low-acid or fouling-prone products with the Alfa Laval Steritherm DSI. This continuous UHT treatment module uses direct steam injection helps prevent product browning, overcooking, and protein denaturation.
As an integral component in a complete aseptic bag-in-box production line, the Steritherm DSI module ensures the integrity of products – from soups, sauces and baby food to coconut milk, dairy and non-dairy, or starch-based products. Backed by a global supplier with a local presence, the fully automated UHT sterilizer with an automatic diagnostics supervision system optimizes uptime and production.
How the Steritherm DSI achieves UHT treatment
Direct steam injection flow chart
Before production begins, the module undergoes sterilization-in-place (SIP) using superheated water. After SIP, the system remains sterile under aseptic conditions until production starts. When the aseptic tank and/or filling machine are ready to receive the processed product, production can start.
Product flow and heating
The product enters the balance tank, the entry point of the Steritherm DSI module. It is first preheated by regeneration in an indirect heat exchanger up to approximately 80°C (176°F). Final heating to sterilization temperature occurs in the steam injector, where high-pressure superheated water is continuously injected directly into the product.
The fully automated module maintains precise control of product temperature and water content. A temperature deviation of more than ±1°C (± 1.8°F) triggers an alarm.
Holding and flash cooling
Sterilization takes place in the holding tube, where the product remains at the desired temperature for the required time. The product then enters a flash vessel operating under vacuum. Pressure and temperature almost instantly drop to 85°C (185°F). Excess water from the injected steam evaporates as vapour and is removed.
The product then enters an optional aseptic homogenizer or can be introduced directly into the cooling section of an indirect heater, where it reaches the required filling temperature.
