BACKWASH STRAINER|gas detection|combustible gas detectors|hazardous gas detection|gas leak detection instruments Backwash often ineffective against stubborn solids which remain in screen openings and reduce performance. Usually cast vessels with pre-determined connection locations and orientations. Fabricated vessels on custom orders only, resulting in substantially higher prices. Backwash must be flowing in order to clean the screen. As screen becomes clogged with resistant solids, backwash intervals increase. Water loss is typically 5% of total flow. Backwash arms usually rotate at 3-4 RPM, resulting in longer backwash times to clean screen. Strainers are typically designed with a screen to pipe ratio of 3:1 using a 1/16” screen slot. If the standard cast vessel is used and a smaller slot size is specified, the net open area decreases resulting in a lower flow rate or a higher pressure drop. All strainers are fabricated to the exact design requirements of each client and are still cost-competitive with cast-vessel backwash strainers from Acme's main competitors. As of June 2007, ACRS strainers can now be ordered with FRP vessels for maximum corrosion resistance in seawater or process applications. Matching media configuration, retention, and materials to your application is easy when you select an Acme backwashing/tubular filtration system. We offer media choices from compact configurations that pack a large amount of surface area into a small amount of space, to simple strainer-type systems for removing larger contaminants.
A common problem in many smaller size automatic self-cleaning strainers (2˝ to 8˝ ) is inefficient backwashing due to debris lodged in the strainer element. A unique vane plate is positioned at the inlet of the strainer element where it contacts the process media before it enters the element. The vane causes the incoming liquid to move in a circular motion, forcing the debris to lay up against the surface of the strainer element rather than impinging on the element and lodging in the element’s openings. Lodged debris in the strainer element can negatively impact the differential pressure across the strainer, resulting in a shut down of the strainer while the element is manually cleaned. Cenpeller Technology helps prevent this problem while making backwashing much easier and more efficient. Widely used in many industries, Automatic Backwash Strainers are a rugged design that provides reliable, efficient, un-attended operation. Also called Automatic Backflush Filters, they remove suspended solids, dirt, and debris from many different water streams and process fluids. The strainers work around the clock with minimal maintenance or operator attention. They provide cost effective continuous protection for downstream equipment, reducing maintenance and downtime for heat exchangers, spray systems, and process equipment. Backwashing: The automatic strainer stays on stream during the backwash cycle, so flow to the process is not interrupted. A backwash cycle is initiated by a differential pressure switch or an adjustable interval timer. During the short backwash cycle an automatic valve opens, and the backwash drive motor is energized to rotate the internal backwash assembly. The backwash assembly has a hollow backwash arm and shaft. As the backwash arm rotates, a seal plate moves along the inlet side of the tubesheet. Each element is cleaned one at a time in sequence, as a small amount of strained water reverses flow, flushing the collected solids through the backwash valve.
An automatic backwash strainer uses some of the fluid already strained to dislodge particulate embedded within the filter element. This is accomplished by effectively reversing the flow through the element and out the drain port using an internal nozzle assembly which slowly rotates within the element. Approximately 5% of the flow is used for backwashing the filter element and the duration of the cleaning cycle is typically 3-5 minutes. Body shall be fabricated out of M.S plate IS 226. Thickness of sheet & sizes shall be as per table below, chamfered pipe with flanges shall be provided at inlet / outlet connections of the Automatic Backwash strainer. Butterfly valves shall be provided at inlet / outlet connections as shown in drawing and included in BOQ. The Automatic Back Wash strainer body shall have two separate chambers properly sealed to avoid mixing of filtered and unfiltered water. A powerful magnet shall be provided in the body to arrest MS particles. Automatic strainer shall have Back-wash system for cleaning the filter elements: A heavy duty Reduction Gear motor unit of stainless steel Body shall be provided at top of upper lid of Automatic Back Wash strainer. A suitable stainless steel shaft SS-304 shall be provided for rotating the backwash arrangements having Bristle Brush for cleaning in side circumference of element. How Automatic Backwash Strainer works : the debris laden dirty fluid enters the strainer’s large bottom chamber where the line velocity gets reduced. Flow continues upward passing in a radial manner through the “sealed” screen element. Unwanted materials are trapped on the inside of the filter element screen. The fluid keeps getting filtered and comes out clean through the outlet nozzle. As the filter screen gets loaded with dirt, the differential pressure keep raising.