What are the disinfection methods of UV sterilizers?

Ultraviolet disinfection systems use UV radiation to kill bacteria and viruses in water; due to their quick disinfection and high sterilization efficiency, they are widely applied in the water treatment industry. What are the structures and methods included in the disinfection process of UV disinfection systems? Today, our editor gives a brief introduction.

Ultraviolet Disinfection Systems: Divided into two systems—closed and open—based on different water flow boundaries.

Closed-loop system

The closed UV ultraviolet sterilizer is a pressure-type device, which encloses the water to be sterilized using a metal cylinder and UV lamps fitted with quartz sleeves.

The cylinder is commonly made of stainless steel, with the inner wall often polished to enhance its reflectivity to UV rays and boost radiation intensity. The number of UV lamps can also be adjusted according to the water treatment volume.

Closed systems are further categorized into open and immersion types. Open disinfectant systems are suitable for medium to large water volume treatment and are commonly used in wastewater treatment plants. Closed disinfectant systems are generally used for medium to small water volume treatment or in situations where pressure disinfection is required and cannot be applied in open channels.

Quartz sleeve UV lamps in various systems can be arranged either perpendicular or parallel to the water flow direction. The parallel system has minimal hydraulic loss and uniform water flow, while the perpendicular system allows for water movement, enhancing sterilization efficiency.

Open System

Water sanitized in the open-type UV sterilizer flows through the unit under gravity, inactivating microorganisms in the process. The open system can be further categorized into immersion and surface-level types.

Immersion method, also known as water-illuminated technique. The ultraviolet lamps with an external concentric quartz sleeve are placed in water, with water flowing around the sleeve. When the lamps (set) need replacement, lifting equipment is used to elevate them to the working surface for operation. This method is relatively complex in construction, but it offers high efficiency and utilization of ultraviolet radiation, excellent results, and ease of maintenance.

Surface water method, also known as surface water irradiation, involves placing an ultraviolet lamp above the water surface, with parallel electron tubes generating parallel ultraviolet light to disinfect the water. This method is simpler than immersion, but it is energy-wasting and has poor sterilization effectiveness, and is rarely used in actual production.