Screening is the first operation at any wastewater treatment works. The screening process involves the removal of large non-biodegradable solids that frequently enter a wastewater works, such as rags, papers, plastics, latex, tins, containers and wood.
Efficient solids removal protects the downstream plant and prevents any possible damage, unnecessary wear tear, pipe blockages and the accumulation of unwanted material that will interfere with the required wastewater treatment processes.
Initial coarse screening, especially on large works with gravity feed should be considered an essential element to provide a barrier to damage. SPIRAC has two main coarse screen selections to offer. MULTIGUARDTM our multi-raked bar screen and RAKEGUARDTM our single articulated rake screen. Depending on channel dimensions and expected incoming screenings and debris loads we can advise the optimum solution for your treatment works inlet.
With the initial interception of influent successfully achieved with a coarse bar screen, we can turn out attention to fine screening. SPIRAC again have two main fine screenings solutions. BANDGUARDTM and FINEGUARDTM can offer 2D screenings of sewage flows down to 3mm.
BANDGUARDTM, vertical band screen can be supplied in a range of sizes to accommodate civil structure limitations and flow requirements. With Ultra High Molecular Weight Polyethylene panels the BANDGUARDTM offers a robust screenings solution. FINEGUARDTM, inclined screen has a number of features to maximise screenings removal. Asymmetric stainless steel screening panels offer the benefit of a step to help retain debris and eliminate rag rolling in front of the screen. The panel profile and self adjusting rotary brush mechanism maximises primary debris removal, while panels are finally cleaned with wash water spray nozzles to complete the cleaning process.
SPIRAC fine screen designs incorporate cranked link chains which enable the screens to be supplied with odd numbers of panels, more accurately achieving the required discharge height and dispenses with a number of small screen assembly items. This simplifies production and future on site repairs and this way maximising screen availability.
SPIROGUARD®combines screening, conveying, dewatering and removal of solids from effluent and process streams in one compact machine. The unit is robust, easy to install and, with only one moving part, virtually maintenance free. Slow speed combined with automatic intermittent operation ensures a reliable and efficient system.