The continuous sterilizer is a highly integrated sterilization system, which mainly includes a vessel for the sterilization process and a fully integrated loading and unloading system.
The entire system involves a series of complex mechanical and electrical technical knowledge. It is not easy and unnecessary for the end user to understand this knowledge in detail.
This article will explain some of the most basic principles of continuous sterilizers to help you get started quickly.
Table of contents:
- Why is it called “continuous”?
- How does the continuous sterilizer work?
- How are the products loaded and unloaded?
- How are the temperature and pressure stability in the sterilization vessel maintained?
- Additional requirements
1. Why is it called “continuous”?
Continuous sterilizers are compared to traditional batch retort sterilizers.
Batch sterilizers process “one batch” of containers of prepackaged products at a time. Batch sterilizers usually consist of single or multiple sterilization vessels. When processing each container batch, each vessel repeats the cycle from loading, door closing, heating, sterilizing, cooling, and door opening to unloading.
The continuous sterilizer only has one vessel. Through the transmission of the chain, the containers are continuously transported into the vessel, passing through the sterilization, cooling, and other areas at a specified speed, and then are transported out. The entire process is continuous.
2. How does the continuous sterilizer work?
Keeping products at a specified temperature for a specified time is the common logic of all equipment that uses temperature to sterilize.
The vessel of the continuous sterilizer is divided into upper and lower areas. The upper area is filled with saturated steam for high-temperature sterilization, and the lower area is filled with cooling water.
After the containers are loaded into the carriers, the carriers are fixed on the chain and enter the vessel as the chain is driven. The containers are first sent into the upper high-temperature area and then moved down layer by layer. The speed of the chain drive is designed in advance to ensure that the product lasts enough time in the high-temperature area to achieve the sterilization effect. The product then enters the cooling water and moves downward layer by layer until it is output out of the vessel.
3. How are the products loaded and unloaded？
1) Carriers
The continuous sterilizer relies on the transmission of the chain to achieve the purpose of continuous sterilization. How to fix the containers on the chain is the first problem we need to solve.
Our solution is to use custom-made carriers; the containers are loaded into the carriers first, and then the carriers are fixed on the chain.
Containers come in all shapes and sizes, and a single type of carrier can’t meet such a wide range of requirements. Therefore, depending on the characteristics of different containers, we generally need to use custom-made carriers.
For example, for round plastic bottles and glass bottles, tube carriers are generally used; for cans, square carriers with self-locking devices are typically used; for stick pouches, we have designed special carriers with many grooves…
2) Loading and unloading
After the carriers are finalized, the second problem we need to solve is how to put the containers into and out of the carriers.
There are two commonly used methods: push rod and manipulator.
The push rods – to push the containers into or out of the carriers. It has a simple structure, and is generally used with tube carriers.
The manipulator will be used when the push rods cannot meet the requirements. For example, for soft plastic bags, a robot is generally used with a suction cup; for printed cans, loading and loading by a robot with a soft suction cup can better protect the cans and avoid scratching their surface.
3) Which type of carrier and loading and unloading method is more suitable for my product?
When choosing the appropriate type of carrier and loading and unloading method, you need to consider the characteristics of the product itself (for example, some products require the carriers to be constantly rotated during the entire sterilization and cooling process), container size and characteristics, production capacity requirements, etc.
We suggest you contact the OUSI technician team. We will select the most suitable one from the existing solutions or, if necessary, specially design your product’s carriers and loading and unloading method.
4. How are the temperature and pressure stability in the vessel maintained?
OUSI has designed a special device for the continuous sterilizer – the water seal valve, which serves as the channel for products to enter and exit the sterilization vessel.
During the entire operation of the continuous sterilizer, the containers continuously enter and exit the vessel through the water seal valve. The water seal valve not only realizes this continuous process but also ensures that the sterilization vessel maintains sufficient sealing so that the temperature and pressure are always stable within the specified range.
5. Additional requirements
Due to the diversity of products and packaging containers, the operation processes of continuous sterilizers are different. When necessary, the continuous sterilizer can meet the requirements through some additional configurations, which include but are not limited to the following:
- Atmospheric Pressure Preheating System
- External Atmospheric Pressure Cooling System
- Pressure Sterilization and Pressure Cooling System