DSI sterilizer is short for direct steam injection/infusion sterilizer, it is a sterilization method in which materials and heating medium (culinary steam) are directly mixed to rapidly heat materials to a specified sterilization temperature. Both steam infusion and steam injection are direct heating systems, steam injection is where steam is injected into the product to be treated, while steam infusion is where the products and culinary steam will be infused into the sterilization tank at the same time to realize the heat treatment. The steam must be of a good quality culinary grade and free from any off-flavors that could alter the flavor of the product.

Because of the short heating time, high heating efficiency, and fully enclosed operation, DSI sterilization technology is widely used in continuous UHT treatment heat sensitive low-acid and easy fouling products, such as milk, plant-based milk(coconut milk, oat milk, soy milk, almond milk), high value-added juices(NFC juice, fruit nectar), beverages, baby food puree, cream, milkshake, sauce and puddings with aseptic productions.

• Low-temperature milk products: 143-158℃ holding for 0.09S—-Flash cooling—65℃ homogenizing—4℃ milk outlet.
• Normal temperature aseptic products:135-142℃ holding for 4-6S—Flashing cooling—80℃ aseptic homogenizing—25℃ material outlet.
• Heat-sensitive aseptic products: 150-160℃ holding for 0.1-0.9S—Flashing cooling—65℃ aseptic homogenizing—25℃ material outlet.

• Gentle heating with direct steam infusion sterilization minimizes thermal gradients compared to other UHT processes, helping to protect important nutrients such as vitamins, resulting in a high-quality, fresh-tasting product. It provides the sterilization rate necessary for commercial aseptic products and can handle a wide range of viscosities, from light soy milk to thick custards and puddings.
• The cooling jacket on the steam sterilization chamber minimizes product foaming or fouling, and the entire direct steam infusion/injection UHT system is fully closed, with lower CIP cleaning frequency, and longer running time compared to indirect UHT processes, Superior processing speeds and longer cleaning intervals ensure higher productivity.
• High-temperature heating(120-150℃adjustable) for a short period of time(0.2-5S) helps the product maintain its fresh flavor while ensuring a very high sterilization rate, resulting in long shelf life of the product.
• The DSI sterilizer heats up and cools down products quickly, the heating and cooling time of the material is short, so the nutrition and color of the product can be well preserved.
• The infusion type can heat the material to 143℃, and the whole heating time is shorter than Inject type sterilizer; But the direct steam injection sterilizer can heat the material to 162℃ maximumly.
• The Flash cooling process performs in a vacuum evaporation tank to ensure precise control of water drainage so that the product is not diluted or concentrated compared to its original state.
• The whole machine has SIP and CIP functions, usually connect with the aseptic tank, aseptic homogenizer and aseptic filler to produce the aseptic products.
• The whole sterilization process is controlled by PLC, fully automatic, product flow is controlled by the flowmeter, product temperature is controlled by a sensor, and product flowing capacity is frequency control, available from 2 tons/hour to 8 tons/hour.
• The whole machine is made of SUS304 or SUS316L, which is full meets the hygiene requirements in the food and beverage processing field.
• The control system adopts international famous brands, such as Siemens S7 series PLC, Shneider eclectic control parts, Danfoss inverter, Spirax Sacro steam control system, Jumo temperature control system, GEA aseptic valve, etc.

The whole machine is composed of product balance tank with level sensor, product pump with frequency control, tubular preheating section, steam injection/infusion tank for sterilizing products, vacuum evaporating tank for flashing cooling, vacuum pump, aseptic product pump,  tubular precooling and final cooling section, aseptic valves, pipes and fittings, electronic control cabinet, control instrument, etc.

The optional equipment can be equipped includes aseptic homogenizer, clean culinary steam generator, rotor or screw pump for high viscosity product transferring.

Before production, the DSI sterilizer will do CIP and SIP process by cleaning solution and culinary steam to keep the sterilizer in an aseptic state. Then the products in the balance tank will be pumped to the tubular preheating section by product pump to heat the materials to 80℃, then the products flow to the sterilizing tank, where the high-pressure culinary steam will also be injected, then the steam and products are fully mixed to heat the material to sterilizing temperature, and the products will be held in a certain time in holding tubes. After sterilization, the products will be pumped into the vacuum flash cooler, where the products will be cooled to 80℃ instantly, and the excess water will form into vapor and flash off. At last, the products can be pumped into an aseptic homogenizer for homogenizing or directly pumped to the tubular cooler to cool down to room temperature for aseptic filling.