Suction-Scanning Technology
Fast, Efficient Self-Cleaning Technology for Continuous Flow of Filtered Water
Amiad's greatest achievement is its research, development and production of suction-scanning technology. Presently, Amiad is the only water filtration manufacturer to offer this technology to the market. This breakthrough has led to the design and production of self-cleaning filters with screen areas that were previously unattainable. Suction-scanning technology combines focused flush with automation to provide 100% cleaning of the screen area. The success of this technology has established Amiad as a global leader in providing water filtration solutions.
Focused Back-Flushing - Complete Cleaning of the Screen Surface
Suction-scanning, also known as focused back-flush creates suction force by reversing flow through a small section of the screen element into a nozzle at the tip of the suction scanner.
The suction-scanner releases flush water into the atmosphere through an exhaust valve. The reversed flow of high velocity water is created by the differential pressure between the positive working pressure of the vessel and the atmospheric pressure at the exhaust valve. This high velocity water stream pulls the debris layer, called a filter cake, off the screen and out the exhaust valve without the need for the nozzles to touch the screen. The suction-scanner is a hollow stainless steel pipe with tubular nozzles evenly spaced along its length. A combination of a threaded drive shaft and motor creates a spiraling motion of the suction scanner nozzles, which sweep across 100% of the screen in a single 15 to 30 second stroke.
Multi-Layer Screen - Optimal Filtration to 10 Microns
Amiad suction-scanning filters incorporate a unique multi-layer stainless steel screen available in degrees of filtration as small as 10. Amiad's engineering team has developed the optimal combination of material strength, filtration efficiency and clean-ability by combining select ratios of screen weave type and patterns, resulting in a high efficiency of filtration. This sophisticated screen assembly allows the accumulating filter cake to be rapidly and totally removed.
Uninterrupted Flow with Minimal Waste
Amiad's suction-scanning technology uses less than 1% of the total process water for cleaning. This is the lowest ratio of process to exhaust water of all competing automated self-cleaning methods; however this ratio can vary depending on specific application conditions.
The self-cleaning cycle is triggered by the accumulation of suspended solids (filter cake) on the screen surface, as measured by the pressure differential. Therefore, cleaning is performed "as needed" - resulting in minimal water and energy waste. Suction-scanning technology eliminates the need for isolating the filter during the self-cleaning cycle. This focused cleaning and the minimal exhaust requirement allow for uninterrupted process flow.
Micro Fiber Technology
The Filtration Media
Textile fibers are widely used for fine filtration in the disposable cartridge filter market. The Amiad MTG filter uses Micro Fiber Technology to create a self-cleaning filter system. The basic filtration element in a "thread" filter is the "thread cassette." Fine threads, which are 10 micron in diameter, are wound over a rigid grooved base plate. Water flows through the thread layers into the grooves and channel the water to specially designed outlets. The rigid base plate supports the thread layers and also plays a major role in the cleaning process of the media. The filter cassettes are mounted on hollow collector pipes.
The Filtration Process
The unfiltered water flows into the cassette package chamber via the filter's inlets. The water flows through the cassette threads. The filtered water, after passing through the cassettes, is collected in the four collector pipes upon which the cassettes are mounted. The small particles are stopped and trapped between the threads.
The Cleaning Mechanics
High-pressure water jets spray through the thread layers, hit the grooved base plate and reject back through the layers again. The contaminant is carried off the cassettes by the reject stream. Therefore, no dirt passes through the filter during back-flush. The filtration mechanics are a combination of surface and depth filtration. The design velocity through the media is 1-40 m/h. The newly developed filter is efficient for drinking water filtration, including the removal of cryptosporidium, as well as for swimming pools, reverse osmosis protection, cooling tower side stream filtration for Legionella reduction, etc.
The Cleaning Process
The filtered water flows from the four collector pipes to the filter's outlets. As dirt builds up on and in the cassettes, the pressure differential across the cassettes increases. When the differential pressure reaches a pre-set adjustable level, it triggers the filtration system's flush sequence. Flush sequences also can be triggered at pre-set timed intervals. The flush sequence is governed by an electronic control unit or by manual input.
Filter Elements
Manually operated filters
A wide range of filter elements and filtration degrees are available for Amiad's manual filters.
Grooved disc elements
These elements are constructed from plastic discs that are stacked onto a telescopic core. The discs are grooved on both sides. These grooves intersect to form the filtration element when compressed on the core. The disc element provides especially effective retention of organic matter. The effective filtration area is comprised of both the outside surface and the channels formed by the intersected grooves. Suspended organic particulate adheres to the grooved surface. Cleaning the cartridge is made simple by the unique design of the telescopic core, which allows the discs to separate during the cleaning process.
Disc elements are available for use with 1"-3" Amiad plastic filters and 2"-4" Amiad steel filters.
Weave-Wire Screen Elements
The weave-wire screen elements are constructed of molded plastic ribs that support a stainless steel or nylon screen. Suspended solids accumulate on the inside surface of the screen. The screen can be removed from the housing to be washed manually. Optional accessories are available to facilitate cleaning without the need to disassemble the filter housing.
