Steritherm PHE

Enhance the safety, quality, and microbiological stability of your liquid food products with the Alfa Laval SterithermTM PHE module. This reliable plate sterilizer inactivates spoilage-causing microorganisms in food during processing. By combining high-temperature heat transfer with optimized hold times, this pre-assembled, skid-mounted system delivers safe sterilization, gentler pasteurization, and consistent product quality while preserving aseptic integrity.

High-performance plate sterilizer with efficient heat recovery

Optimize sterilization of dairy, food and beverage products
Maximize energy efficiency through heat recovery and reuse
Ensure gentle sterilization of heat-sensitive food products
Reduce footprint with space-efficient design
Leverage global expertise with local support and service

The Steritherm PHE is an aseptic plate sterilizer designed specifically for heat-sensitive food products. Combining efficient heat transfer with optimized holding times, it gently sterilizes liquid food products while preserving flavour, texture, and nutritional value. High heat recovery and reuse make the PHE process energy-efficient and cost-effective.

Built for modern food production lines, the skid-mounted Alfa Laval PHE module enables fast, seamless integration. Fully validated for aseptic use, its modular design allows easy adaptation to changing production demands. Whether connected to aseptic tanks, filling machines, or other hygienic processing units, it ensures reliable, continuous control over sterilization parameters 24/7.

How the plate sterilizer Steritherm PHE works

The plate heat exchanger consists of a pack of stainless-steel plates mounted in a frame with separate sections for pre-heating, final heating, and cooling.

Corrugated plates with unique plate patterns optimize heat transfer. Supporting points on the plate hold the plates apart and form narrow channels between them. The liquids enter and leave the channels through ports in the plate corners. Varying patterns of open and blind holes route fluids from one channel to the other. Gaskets around the plate edges and the ports form the channel boundaries, preventing external leakage and internal mixing.

Balance tank

Before production begins, the Steritherm PHE undergoes sterilization-in-place (SIP) using superheated water at 125°C (257°F). Thirty minutes after sterilization, the product flows through the balance tank into the module. A programmable logic controller regulates pump speed, transferring the product to maintain a constant feed rate to the heat exchanger based on signals from a flow meter. A temperature transmitter and a pressure transmitter monitor the inlet product temperature and tank pressure.

Pre-heating by direct regeneration

Direct energy recovery pre-heats the incoming untreated product, reducing the demand for heating and cooling media. The hot sterilized product raises the temperature of the cold incoming product in the regenerative heat exchanger. The treated product is maintained at a higher pressure than the untreated product to prevent cross-contamination.

Final heating to the sterilization temperature

Final heating is achieved through hot water recirculation. A dedicated hot water set generates hot water using steam. A temperature transmitter monitors the product temperature at the heat exchanger outlet and adjusts the steam supply via a modulating valve to maintain precise control.

The temperature difference between the hot water and the product is kept very low to prevent product burning and reduce plate fouling. Once the product reaches the desired sterilization temperature, it is held in an insulated holding cell to ensure consistent and effective sterilization.

Cooling

The product cools to the final temperature in two stages. First, the regeneration section mentioned above cools the product. The second and last stage uses a cooling medium, chilled water, ice water, or propylene glycol, depending on the requirements, to cool the product to the desired outlet temperature. A temperature transmitter controls the chilled media, measures the product's outlet temperature, and sends commands to the modulating valve on the cooling media pipeline.

Cleaning-in-place

Under normal operating conditions, all product-contact surfaces are cleaned in place without requiring module disassembly. Recommended cleaning intervals vary, depending on the product type and processing temperatures.

Control system

Automated operation controls start and stop functions, set point, and piping and instrumentation diagram (P&ID). Control parameters can be reviewed and adjusted. The system displays relevant process data, including as plant status, real-time temperatures, and flow rates, and alarm status.

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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: