Steritherm VLM
Increase microbiological product stability by removing or inactivating microorganisms that cause product spoilage. The Alfa Laval Steritherm VLM is an aseptic multitube heat treatment system that sterilizes low- to medium viscosity products containing fibres and small particles. Based on a tubular heat exchanger, it ensures gentle product treatment and uniform heating and cooling. Versatile and robust, this aseptic sterilizer maximizes uptime and minimizes maintenance.
Secure process and product safety for low to medium viscosity food products through sterilization
- More uptime for fouling-prone applications, like high-fibre juices, compared to other technologies
- Reliable, low-cost operation with long run times and higher heat transfer efficiency than tube-in-tube designs
- Versatile handling of various capacities and product formulations
- High hygiene levels due to thorough cleaning-in-place
- Near maintenance-free operation due to no moving parts and low service requirements
Safeguard fresh food products from spoilage with the Alfa Laval Steritherm VLM.
The Alfa Laval Viscoline™ multitube tubular heat exchanger is at its core for effective sterilization. This multitube sterilizer treats products like milk, eggs, fruit and vegetable purees, fruit juices with pulp, ensuring food safety.
Pre-assembled and skid-mounted, the unit comes ready to install between an aseptic tank and filler. It ensures straightforward operation, safety throughout the packaging process, and next-to-no maintenance.
Choose models for:
- the removal of air from the product before treatment with integration of the Alfa Laval Alrox deaeration module
- direct and indirect heat recovery to improve energy efficiency
Understanding how the tubular sterilizer works
Sterilization
Before production begins, the Steritherm VLM undergoes sterilization-in-place. Superheated water at 125 °C (257°F) circulates through the unit for 30 minutes to ensure hygienic start-up conditions.
Balance tank
The product enters a balance tank, and a feed pump transfers it to the heat exchanger. A flow meter sends signals to the pump, ensuring a constant feed rate. Temperature and pressure transmitters continuously monitor the inlet temperature and pressure.
Indirect pre-heating (regeneration)
A dedicated closed water loop preheats the cold product. Indirect energy recovery reduces the need for external heating and cooling, improving overall energy efficiency. The product is maintained under higher pressure than the heating medium to ensure safe and stable processing.
Final heating and holding
Final heating to the sterilization temperature is achieved through hot water recirculation. A dedicated unit generates hot water by means of steam. A temperature transmitter at the heat exchanger outlet measures product temperature and sends data to the control system. The control system regulates the steam input via a modulating valve to maintain precise product sterilization conditions. The product then flows into an insulated holding tube, where it remains for the time required to achieve sterility.
Cooling
To reach the required product filling temperature, the cooling process may be carried out in three stages as required:
- Indirect cooling through the same closed water loop used for the preheating, improving overall energy efficiency
- Cooling with tower water
- Final cooling with chilled water or glycol solution in a counter-current flow
To ensure the correct final temperature, a temperature transmitter continuously measures the flow rate of the final cooling media. It sends signals to the control unit via a modulating valve installed on the cooling media pipeline and measures the product outlet temperature.
Cleaning-in-Place (CIP)
Under normal conditions, all product-contact surfaces are cleaned without dismantling the Steritherm VLM. Cleaning frequency depends on the product characteristics and operating temperatures.
Control system
The sterilizer operates automatically. Start and stop functions, set point and PID control parameters can be set and inspected. The control system displays relevant process data, including plant status, temperatures, flow rates, and alarm status.
Products
Food system services
Alfa Laval Food system services help extend the performance of your food systems by maximizing the performance of your processes. This enables you to:
- Continually improve your operations to maintain competitive advantage
- Focus on uptime, optimization and availability
- Maximize return on investment throughout the life cycle of your food systems
Learn more about our service offer for food systems
