How does an Automatic Backwash Filter work

JX Filtration October 12, 2023 Automatic Backwash Filter

An Automatic Backwash Filter is a sophisticated filtration system designed to efficiently remove contaminants and particles from liquids or gases in industrial and commercial applications. Its operation involves a combination of intelligent control mechanisms and advanced filter media to ensure optimal filtration performance. Here's how an Automatic Backwash Filter works:

Filtration Phase:
- The process begins with the filtration phase. Contaminated fluid enters the filter housing from the inlet.
- The fluid flows through the filter media, typically a fine mesh or screen, which captures impurities, particles, and contaminants.
Accumulation of Contaminants:
- Over time, as the filter media captures contaminants, it begins to accumulate them. This buildup can reduce the efficiency of the filtration system.
Differential Pressure Sensing:
- Automatic Backwash Filters are equipped with sensors that monitor the pressure difference between the inlet and outlet sides of the filter. When the pressure difference exceeds a predefined threshold, it indicates that the filter media is becoming clogged with contaminants.
Initiation of Backwash Cycle:
- In response to the rising pressure differential, the system initiates a backwash cycle. This cycle is typically automatic and controlled by a programmable logic controller (PLC) or a similar control system.
Reverse Flow:
- During the backwash cycle, the direction of fluid flow is reversed. The control system diverts a portion of the clean effluent or an external cleaning fluid (in some cases) to the outlet side of the filter.
Dislodging Contaminants:
- The reverse flow dislodges and lifts the accumulated contaminants from the filter media. These contaminants are carried away in the reverse flow of fluid.
Drainage and Disposal:
- The dislodged contaminants are transported to a drain or collection point, where they can be safely disposed of or processed as required.
Resumption of Filtration:
- After the backwash cycle is completed and the filter media is cleared of contaminants, the system returns to the filtration phase. It resumes its duty of efficiently capturing impurities from the incoming fluid.
Continuous Operation:
- The Automatic Backwash Filter operates continuously, monitoring the pressure differential and initiating backwash cycles as needed. This ensures that the filtration system remains efficient, providing consistent, high-quality filtrate.

The automatic backwash process is an efficient and reliable method for maintaining the performance of the filter without requiring manual intervention. It is particularly beneficial in applications where uninterrupted filtration is essential, such as in the water treatment, chemical, and food and beverage industries.