The Xinxiang Lifilter shallow sand filter operates based on a straightforward yet highly effective principle of water filtration.
At its core, it utilizes a bed of carefully selected sand grains as the primary filtering medium. When water enters the filter, it first passes through a distribution system that evenly spreads the incoming flow across the entire surface area of the sand bed. This is crucial as it ensures that the water is uniformly filtered, preventing any preferential channels or bypassing of unfiltered water.
As the water percolates down through the sand, which typically has a specific particle size range and porosity, suspended solids, sediment, debris, and even some microscopic impurities are trapped within the interstitial spaces between the sand grains. The physical structure of the sand bed acts like a sieve, with the small pores and tortuous pathways effectively capturing particles that are larger than the pore openings.
Over time, as more and more impurities accumulate in the sand bed, the resistance to water flow increases, leading to a rise in the pressure drop across the filter. This pressure differential serves as a key indicator for the filter's need for maintenance, most notably, the backwashing process.
When the preset pressure drop threshold is reached or after a certain period of operation, the automatic backwashing mechanism is activated. During backwashing, the flow direction of water is reversed. A combination of high - velocity water jets and agitation helps to dislodge the trapped impurities from the sand grains. The loosened impurities are then carried away with the backwash water and discharged out of the filter through a dedicated outlet, restoring the sand bed's filtration capacity and allowing the filter to resume its normal operation.
This continuous cycle of filtration and backwashing enables the shallow sand filter to provide a consistent supply of purified water, making it suitable for a wide array of applications.
Proper maintenance is essential to ensure the long - term efficiency and reliability of the Xinxiang Lifilter shallow sand filter.
Backwashing is the most fundamental maintenance task. As mentioned earlier, it should be carried out when the pressure drop across the filter indicates a significant build - up of impurities. The frequency of backwashing depends on various factors such as the quality of the incoming water, the flow rate, and the specific application. In general, for relatively clean water sources and lower flow rates, backwashing might be required less frequently, perhaps every few days or even weeks. However, in more demanding industrial settings with highly turbid water or high flow demands, it could be necessary daily.
During backwashing, it's crucial to monitor the process to ensure that the water jets are strong enough to effectively remove the trapped impurities and that the backwash water is being discharged properly. If the backwash seems weak or incomplete, it could be due to clogged nozzles or insufficient water pressure, which should be addressed promptly.
Periodically, the condition of the sand bed needs to be examined. Look for signs of uneven settling, compaction, or the presence of large clumps of impurities that might not have been fully removed during backwashing. If the sand bed has become compacted, it can reduce the porosity and filtration efficiency. In such cases, gentle agitation or even partial replacement of the sand might be required.
Also, check for any loss of sand due to erosion or improper installation. Replacing lost sand promptly with the correct grade and quality is vital to maintain the integrity of the filtration process.
The valves and pipes associated with the filter are critical components that require regular upkeep. Inspect all valves for proper operation, checking for leaks, sticking, or malfunctioning. Lubricate valve stems regularly to ensure smooth opening and closing.
For the pipes, look for signs of corrosion, especially in applications where the water has a high chemical content. Leaking pipe joints can lead to water wastage and a drop in system pressure. Repair or replace any damaged pipes or fittings immediately.
