Industrial filters and strainers are a core component of fluid systems that filter out unwanted solids and potentially damaging particulates from the liquid material and trap them for removal. This ensures the system stays clean, which ultimately contributes to preserving its performance in the long term and extending the service life of various mechanical devices it consists of, including pumps, valves, and more.
That said, a traditional industrial strainer typically requires manual intervention (i.e., frequent removal of the strainer for emptying and cleaning) since the continuous accumulation of solids will eventually impede the flow of the process fluid. In most cases, this requires the flow to be temporarily shut down or to bypass the strainer assembly. But thanks to continuous innovation in fluid processing technologies, this inconvenience and inefficiency are completely solved by a motorised and automatic self-cleaning strainer. Read on to learn more about what this solution provides and the use cases where it shines.
What are automatic self-cleaning strainers?
Automatic self-cleaning strainers serve the same purpose as simple strainers, but unlike their traditional counterparts, they no longer require manual cleaning or replacement. As their name suggests, these improved strainers and filters in Singapore are designed to clean themselves during operation automatically. This self-cleaning feature is made possible through a combination of mechanical and electronic components that remove accumulated debris from the straining element, thereby maintaining consistent flow rates and reducing downtime.
In most automatic strainer designs, the liquid enters from its bottom inlet, flows upwards, and passes through the entire filtration system, and exits as clean fluid. The debris that gets trapped is then pushed to a designated collection and removal area that gets opened by a flush valve whenever the system detects that the pressure reaches a certain threshold.
A few mechanisms that are common among different self-cleaning strainer models include:
- Mechanical scraping: This involves using blades to scrape off the filter’s surface.
- Backwashing: The strainer reverses the flow of the incoming liquid to send some of it back through the filter and effectively dislodge the trapped debris, allowing it to be sent to the collection area.
- Continuous flushing: Strainers that use this method leverage a bypass stream to constantly dislodge and remove contaminants while the process fluid flows through the strainers.
- Ultrasonic cleaning: High-frequency vibrations break up stubborn debris so they can more easily be dislodged and carried away to the collection area.
The two main types of self-cleaning strainers
1. Mechanically cleaned strainers
Mechanically cleaned filters come in a stainless steel housing that features a filter screen. The process liquid enters this screen and exits through an outlet while any solid particles it may contain get left behind and trapped. Once the filter needs cleaning, a spring-loaded cleaning disc within the housing physically moves up and down to wipe the filter clean in both directions.
Afterwards, the disc pushes the dislodged solids to the bottom of the housing and flushes them out through a flushing valve. All these steps take place while the filter is still running to preserve process efficiency and does not require the use of disposable filters, helping maintain a consistent low pressure differential.
2. Tubular backwash strainers
Tubular backwashing strainers work by replacing cartridge or bag filters, which are primarily designed to catch granular particulates in high flow rate applications. Its backwash sequence activates once differential pressure reaches a set threshold, at which point the process fluid’s flow is reversed to dislodge the accumulated debris on the filter’s surface. The base of the strainer features an outlet where the solids can then be purged from the system.
Conclusion
Automatic self-cleaning strainers offer significant advantages over simple and duplex strainers, particularly in applications where continuous operation and minimal maintenance are critical. Their advanced design and automated cleaning mechanism make them an essential component in various industries, ensuring efficient and reliable fluid filtration. That said, there are several factors to consider before investing in them, such as your application’s operating conditions, the contaminants present in the fluid, and the nature of the process involved, be it a batch process or a continuous process.
