Acme Automatic Scraper Strainers Overview of Technical Advantages and Product Design G.S. Presser, P. Eng. November 2004
Advantages of Scraper Strainers Can automatically remove large and small particles, unlike backwash strainers. Solids accumulate at the bottom of the vessel and are blown down using dirty water, in place of backwash from the clean side of the screen. Scraper mechanism eliminates stapling and blinding. Special designs effective for low intake pressure or suction-side applications. Flexible control systems to reduce liquid loss during solids blowdown.
View of Scraping Mechanism All SS316L or Monel construction regardless of vessel material. Durable wedgewire screen prevents blockage. Spring-loaded blade and brush maintain contact with screen as they wear. Large open area between scraper supports to allow large solids to fall directly to collection area.
Problems With Backwash Strainers Typical Designs Large solids and bio-fouling cannot be removed by these designs.
Membrane filter pre-screening Our smallest strainer-a 6 vessel good for connections up to 3, 200 USGPM. Optional bypass skid to maintain flow during servicing. Compact design, easy to install Available in CS, SS304/316, Alloy 20, Monel and Titanium. Filtration down to 75 micron. Skid increases the efficiency and reduces maintenance requirements of downstream equipment.
Raw seawater intake for desalination plant Three 24 inlet/outlet strainers in SS316L for the Dunore Point water treatment plant in Ireland. 5mm filtration, using a collector system bracketed by gate valves for solids removal. Acme s largest SS strainers to date.
Gate valve isolation system The Dunore Point pumps could not tolerate a loss of flow or pressure upstream; The strainer blowdown had to be isolated from the regular flow; Two 8 SS gate valves were used to bracket a collector section; Water was injected to assist in dumping the solids into a trough for disposal.
Low pressure/suction side design 4 CS strainer designed for installation in a hazardous area for sludge filtration; Low pressure in system meant that line pressure was insufficient for adequate solids blowdown; Gate valve closes to isolate collector while jets add pressurized water to assist blowdown; Uninterrupted flow.
Application: River Water Intake 18 connections, 11,000 GPM off the Columbia river. 400 micron filtration for a smelting furnace cooling water application. In operation since 1996 with very little downtime. Complete package with controls and blowdown valve.
Wastewater pre-treatment Our smallest strainer-a 6 vessel good for connections up to 3. Used to remove solids in a multistage filtration project in NYC. Compact design, easy to install Available in CS, SS304/316, Alloy 20 and Titanium. Filtration down to 75 micron.
Application: Saltwater Intake 10 In-line strainer fabricated in CS with special coal tar epoxy coating. Used for saltwater intake at the Tynes Bay Bermuda water treatment facility. Special Ashcroft differential pressure switch with diaphragm seals for islolation. Separate control panel.
Jacketed strainers for viscous fluids 6 SS304L steam jacketed strainers for a CSX terminal. Jacket designed to keep the asphalt fluid during the transfer process. Solids removed manually using a hand valve at the end of a batch. U stamp vessel.
Pump Seal Water Protection 3 SS316L 100 micron filter used as a first pass in a multi-stage seal water filtration skid at a power plant. Strainer output goes to two cyclone units that provide filtration down to 5 micron. Note the booster pumps to increase velocity for the 5 micron filters.
Sewage/stormwater filtration Strainer designed to automatically remove up to 6 stones from a waste slurry; Tall collector bracketed by gate valves connects to flange on bottom of vessel; Collector fills with debris, top gate valve closes and collector is dewatered prior to dump; Ideal for applications where a settling tank is impractical.
Where Can You Use an Automatic Strainer? River and lake water intakes with manual basket strainers or no strainers at all. Old duplex strainers in hard to reach areas, or that plug up frequently. Replace older automatic strainers manufactured by Zurn, RP Adams, Kinney, Tate Andale, Hayward and Spirax Sarco (scraper unit). Low pressure situations like gravity flow from tanks. Intakes with heavy solids loading, large solids and viscous fluids.
Things to Remember About Acme A custom manufacturer of strainers, process heating equipment and gas detection systems. In-house capabilities for mechanical, electrical and electronic systems and controls. Equipment made for your customer s specific requirements at a standard product price. Small, responsive company with accessible and accountable management.