Product Introduction

The UHT plate‑type sterilizer comprises a plate heat exchanger, a centrifugal sanitary pump, a material balance tank, a hot‑water system (including a hot‑water tank, a hot‑water pump, a water heater, and a manual steam control valve), an electrical control cabinet, pneumatic three‑way reflux valves (hereinafter referred to as “reflux valves”) with associated piping, and a supporting frame, forming an integrated structural configuration. The plate heat exchanger is configured into multi‑stage process sections—preheating, homogenization (not included in this complete set), sterilization, holding, and cooling—according to process requirements.

Working principle

The UHT plate heat exchanger is the heart of the complete equipment, comprising numerous plates with edge seals and gaskets, as well as intermediate plates, movable pressure plates, and insulated coil tubes. The plates are arranged in a strictly prescribed sequence according to the process flow diagram and assembled by stacking and clamping. Between every two plates, a fluid channel is formed.
Two different fluids flow into the plate heat exchanger:
1. Processed materials (hereinafter referred to as “materials”): such as milk, etc.
2. Working fluids: hot water, superheated water (water at a temperature above 100°C that does not boil under a given pressure), cooling water, ice water, and others.
The two distinct fluids enter adjacent flow channels of the plate heat exchanger, each following its own path without any cross‑contamination or mixing, yet continuously exchanging heat.

Product Applications

UHT plate heat sterilizers are widely used for ultra-high-temperature short-time sterilization of beverages, dairy products, fruit juices, alcoholic drinks, and other food products.
1. Milk beverage
Milk‑based beverages are drinks made from fresh milk or dairy products, processed either through fermentation or without it, with a protein content of at least 1%. During processing, they often contain added ingredients such as thickeners, sugars, stabilizers, and acidulants. The sterilization process for these beverages, conducted at 135–150°C for 2–8 seconds, is known as ultra‑high‑temperature short‑time (UHT) sterilization. Even after UHT treatment, milk may still harbor viable spores or other microorganisms; however, these do not proliferate to levels that would cause spoilage, resulting in a product that is “commercially sterile.”

2. Fruit and vegetable juice beverages
Fruit and vegetable juice beverages are produced by processing various fruits and vegetables or their concentrated juices (pulps) through key steps such as pretreatment, juicing, formulation, sterilization, aseptic filling, or hot filling. The appropriateness of the sterilization process directly affects both the shelf life and the overall quality of these products. The primary objectives of sterilizing fruit and vegetable juice beverages are to eliminate microorganisms, prevent spoilage, and inactivate enzymatic activity. In practice, ultra‑high‑temperature short‑time (UHT) sterilization equipment is commonly employed: after degassing and homogenization, the juice is rapidly pumped into a UHT sterilizer, where it is quickly heated to 93 ± 2°C and held at that temperature for 15–30 seconds to achieve effective sterilization; under special conditions, an alternative approach involves heating at temperatures above 120°C for 3–5 seconds.

3. Alcoholic Beverages
Filtered beer still contains a small number of live yeast cells or contaminating microorganisms. To ensure its biological stability, these live yeast cells and contaminants must be eliminated through pasteurization. However, in actual production, pasteurization typically requires lengthy processing times, entails substantial capital investment, and increases operating costs. Nowadays, a widely adopted filling method abroad involves pasteurizing the beer after it has been clarified—specifically, using ultra‑high‑temperature short‑time (UHT) sterilization. Using UHT…
High‑temperature short‑time pasteurization (HTST) technology maximizes beer freshness, minimizes the degradation of flavor compounds, delivers a well‑balanced mouthfeel, and provides superior microbial inactivation.

4. Tea beverages
The pH of tea beverages typically ranges from 5 to 7, classifying them as mildly acidic drinks. The microorganisms primarily responsible for spoilage are bacteria; therefore, to ensure safety and shelf life, tea beverages must undergo sterilization. Due to the complex composition of tea infusions and the inherent instability of their systems—particularly in green tea, which exhibits the lowest redox potential and greatest system instability—their sensory qualities can change significantly following thermal processing, especially sterilization. However, UHT sterilization helps prevent darkening of color and flavor deterioration after treatment, while the addition of β‑cyclodextrin and vitamin C can enhance sterilization efficacy. Furthermore, incorporating preservatives can either bolster sterilization performance or shorten the required processing time. During post‑sterilization filling, sparging with nitrogen or carbon dioxide to displace oxygen can help stabilize catechins in the tea infusion.

Product Features

1. Small footprint, minimal auxiliary equipment, and low capital investment.
2. When cleaning the system, this UHT unit must be equipped with a CIP section. Disassembling and cleaning plate heat exchangers is relatively cumbersome.
3. Since preheating, sterilization, and final material cooling are all carried out using plate heat exchangers, the heat supply can be easily adjusted by adding or removing plates, thereby achieving temperature profiles that meet various process requirements. Consequently, this system offers a broad range of applicability and flexible operation.
4. This process is designed for fruit juice: first, the material is preheated; then it passes through a homogenizer to break down fat globules; finally, it enters a plate heat exchanger for pasteurization. For other types of materials, the homogenizer may need to be positioned after the pasteurization step.