SHANDONG DINGTAISHENG MACHINERY TECHNOLOGY CO., LTD.

Working Principle

Products are loaded into the sterilization retort, and the retort door is closed. The door is secured by a triple-redundancy safety interlock mechanism. Throughout the entire process, the retort door remains mechanically locked.

The sterilization process proceeds automatically according to a pre-programmed recipe entered into the PLC-based microprocessor controller.

A specific volume of process water is maintained at the bottom of the retort. If necessary, this water can be automatically injected at the commencement of the heating phase. For hot-filled products, this water can be preheated in a separate hot water tank prior to injection. Throughout the entire sterilization cycle, this process water is circulated and sprayed onto the products via a high-flow pump and a series of four-way nozzles strategically positioned above each product tray. This ensures that every item—regardless of its position on the tray (top or bottom tier, front or back, left or right)—achieves an identical level of sterilization efficacy. Consequently, optimal heating and sterilization results are achieved. Thanks to the precise orientation of the nozzles, accurate, uniform, and thorough distribution of hot water is ensured across the center of every tray. This system effectively minimizes temperature non-uniformity within the chamber of the large-scale sterilization retort.

A spiral-tube heat exchanger is installed within the retort chamber. During the heating and cooling phases, process water flows through one side of the exchanger, while steam or cooling water flows through the other. This design prevents the products undergoing sterilization from coming into direct contact with the steam or cooling water, thereby facilitating a sterile heating and cooling process.

Throughout the entire operation, compressed air is automatically injected into or vented from the retort via automated valves, allowing the system to precisely control the internal pressure according to the programmed parameters. Because the system utilizes water-spray sterilization, the internal pressure of the retort remains independent of temperature fluctuations. Furthermore, the pressure can be freely adjusted to suit the specific packaging requirements of different products, thereby endowing the equipment with broad versatility across various packaging formats (including three-piece cans, two-piece cans, flexible pouches, glass bottles, plastic containers, etc.).

Upon the completion of the sterilization cycle, an audible alarm signal is triggered. At this point, the retort door may be opened to unload the processed batch, after which the system is ready to proceed with the sterilization of the next batch of products.

The temperature uniformity within the retort chamber is maintained within a tolerance of ±0.5°C, while pressure control is maintained within ±0.05 bar.


Advantages

● Precise Temperature Control and Exceptional Heat Distribution

The four-way nozzles positioned above each product tray ensure that every item—regardless of its specific location within the tray stack (top or bottom tier, front or back, left or right)—receives identical heating and sterilization treatment, thereby guaranteeing optimal heating and sterilization quality. The temperature control module (D-TOP system) developed by DTS Corporation offers up to 12 levels of temperature control. Depending on the specific product and process recipe, users can select either stepped or linear heating modes, thereby maximizing batch-to-batch repeatability and stability. Temperature control accuracy can be maintained within ±0.5°C.

● Precise Pressure Control, Adaptable to Various Packaging Formats

The pressure control module (D-TOP system) developed by DTS continuously regulates pressure throughout the entire process to compensate for internal pressure fluctuations within the product packaging. This minimizes packaging deformation—whether dealing with rigid containers such as tin cans, aluminum cans, or plastic bottles, or with flexible packaging such as plastic trays or pouches—effortlessly meeting the requirements for all formats. Pressure can be controlled within a tolerance of ±0.05 Bar.

● Ensuring High Hygiene Standards for Packaged Products

This heat exchanger employs an indirect heating and cooling method, ensuring that steam and cooling water do not come into direct contact with the process water. Impurities present in the steam and cooling water are prevented from entering the sterilization retort, thereby eliminating the risk of secondary product contamination. Furthermore, this design obviates the need for water treatment chemicals (such as chlorine) and significantly extends the service life of the heat exchanger.

● Compliance with FDA/USDA Standards

DTS boasts a team of highly experienced thermal validation experts and is a proud member of the U.S. IFTPS (Institute for Thermal Processing Specialists). The company collaborates extensively with FDA-recognized third-party thermal validation agencies. Through extensive experience serving numerous North American clients, DTS has gained deep familiarity with FDA/USDA regulatory requirements and cutting-edge sterilization technologies.

● Energy-Efficient and Environmentally Friendly

A minimal volume of process water is rapidly circulated to quickly achieve the predetermined sterilization temperature.

Low-noise operation creates a quiet and comfortable working environment.

Unlike pure steam sterilization systems, this method requires no venting prior to heating; this significantly reduces steam loss, resulting in steam savings of approximately 30%.