Pasteurization Unit (HTST)

Working Principle

The process flow is built on a staged cycle that guarantees food safety:

1. Balance tank (BTD): The product is first taken into a constant-level balance tank and fed from there to the plate heat exchanger.
2. Regeneration (pre-heating): The pasteurized hot product is used to pre-heat the incoming cold product. This heat recovery significantly lowers the energy needed to reach pasteurization temperature.
3. Heating: The product is raised to the targeted pasteurization temperature via a hot water or steam circuit.
4. Holding tube: A stainless steel pipeline with a calculated hydraulic slope holds the product at the target temperature for the legally required time, ensuring correct pasteurization.
5. Flow diversion valve (FDV): If the temperature drops below the set point, the valve activates and automatically returns the product to the balance tank. This prevents unpasteurized product from passing to the filling line.
6. Cooling: At the outlet, the product is typically cooled to 4 °C for cold filling or storage.

Technical Specifications

The following values are typical references for standard HTST milk pasteurization; they are configured according to product type and process requirements.

Parameter	Value
Capacity options	500 – 1,000 – 2,000 – 3,000 – 5,000 L/hour
Product inlet temperature	4 °C
Pasteurization temperature	72 °C
Product outlet temperature	4 °C
Holding time	15 sec
Hot water temperature	74 °C
Cooling (glycol) water	4 °C

Consult the HOMMAK sales team for other operating parameters, capacities and special product applications.

Material and Hygiene

• Product-contact parts: AISI 304 (AISI 316L plates on request)
• Control panel and frame: AISI 304 stainless steel
• Product-contact gaskets: EPDM and NBR
• Surface finish: Ra ≤ 0.8 µm

The entire system is designed with a hygienic production philosophy compliant with HACCP and international food safety requirements.

Unit Design and Components

The compact unit is delivered on a single stainless steel chassis and includes the following main components:

• Constant-level balance tank (AISI 304)
• Hygienic feed pump
• Plate heat exchanger with 1, 2 or 3 stages depending on the process
• Slightly inclined holding tube for full pump drainage
• Automatic flow diversion valve and manually operated butterfly valves
• 3-way proportional valve with electro-pneumatic positioner for hot water
• Stainless steel chassis with height-adjustable feet
• PLC control panel with temperature regulator

Optional Equipment

• Steam-heated hot water generation circuit
• Flow control for the feed pump with a frequency converter and electromagnetic flowmeter on the control panel
• Paper or digital temperature/flow recorder
• Special heat exchanger plates for products containing suspended solid particles
• 4-stage heat exchanger for homogenizer and cream-separator integration
• Different temperature and holding-time modes (yogurt, cream, fruit juice, etc.)

Applications

HOMMAK pasteurization units are used in different sectors:

• Milk and dairy products: Raw milk, yogurt milk, cream, drinking milk
• Beverages and fruit juice: Fruit juices, nectar, iced tea, plant-based drinks
• Food processing: Sauce, paste, liquid egg and similar fluid products

Integration with HOMMAK Process Solutions

The pasteurization unit can be set up as a complete production line together with HOMMAK’s other process equipment. A high-pressure homogenizer to increase the viscosity and stability of the milk, a positive-displacement piston pump to transfer viscous products, a Hommix powder-liquid mixer to prepare powder/liquid recipes and a CIP system for line hygiene are integrated under a single engineering roof. This way, supply, commissioning and service are handled from a single source.

Frequently Asked Questions

What is HTST pasteurization?

HTST (High Temperature Short Time) is a continuous pasteurization method in which the product is raised to a high temperature for a short time. For milk, it is usually applied at 72 °C for 15 seconds. This method destroys pathogens while largely preserving the product’s taste and nutritional value.

At what temperature does a pasteurization unit operate?

Standard milk pasteurization is carried out at around 72 °C with a 15-second holding time. The temperature and time are configured by HOMMAK according to the product’s type, viscosity and targeted shelf life. Different parameters may be used for products such as fruit juice, cream or sauce.

What is the difference between a pasteurizer and a homogenizer?

A pasteurizer makes the product microbiologically safe through heat treatment. A homogenizer, on the other hand, micronizes particles under high pressure to give the product a permanently homogeneous structure. On milk lines, the two pieces of equipment are mostly used together, in sequence.

Does a pasteurization unit save energy?

Yes. Thanks to multi-stage regeneration, the pasteurized hot product is used to pre-heat the incoming cold product. This heat recovery significantly lowers the energy consumption needed for heating and cooling.

In which capacities is it available?

HOMMAK pasteurization units can be designed in capacities ranging from 500 L/hour to 5,000 L/hour and above, from small businesses to large facilities. Contact our sales team for the model that suits your needs.