Methods of removing solids from liquids

Abstract

A method of removing solid matter from liquid using two or more sets of screening devices installed in series. Each set of screening devices consists of one or more identical or nearly identical screening devices. Each downstream set of screening devices has smaller openings than the preceding upstream set of screening devices. Solid matter collected by the screening devices is automatically discharged onto two or more conveyor systems that deposit the material onto one or more central collection areas for final removal and disposal. The present invention uses screening devices in a special configuration to achieve enhanced removal of solid matter from liquid (i.e. a series installation with screen opening size decreasing in a downstream direction).

1 . A method for collecting objects or materials from a conduit of moving liquid comprising:
 placing in series, within the conduit, at least two sets of screening devices having self-cleaning apparatuses, such that objects or materials are collected as the liquid flows through the screening devices;   removing the collected objects or materials from the screening devices utilizing the self-cleaning apparatuses; and   depositing the removed objects or materials onto a conveyor system for transport to one or more collection areas.   
     
     
         2 . The method, according to  claim 1 , wherein the conduit is a channel, canal, or other man-made waterway. 
     
     
         3 . The method, according to  claim 1 , wherein the conduit is a natural flowing waterway. 
     
     
         4 . The method, according to  claim 1 , wherein each set comprises screens of the same or approximately the same size openings. 
     
     
         5 . The method, according to  claim 1 , wherein a series comprises at least two sets, wherein one or more sets having the largest openings are placed in a more upstream position and sets with successively smaller openings are placed further downstream, such that one or more sets having the smallest openings are in the most downstream position. 
     
     
         6 . The method, according to  claim 5 , wherein at least one set is placed facing upstream, substantially perpendicular to the liquid flow. 
     
     
         7 . The method, according to  claim 5 , wherein at least one set is tilted such that the screen face forms an angle of approximately 95° to approximately 140° relative to the liquid flow. 
     
     
         8 . The method, according to  claim 5 , wherein a series comprises at least one downstream set having more screens than an upstream set. 
     
     
         9 . The method, according to  claim 1 , comprising independently operating bar screen devices with self-cleaning apparatuses. 
     
     
         10 . The method, according to  claim 9 , wherein the self-cleaning apparatuses are screen scrapers. 
     
     
         11 . The method, according to  claim 10 , further comprising a dedicated conveyor system for each set of screens for transport of collected objects or materials to a collection site. 
     
     
         12 . The method, according to  claim 11 , further comprising one or more subsidiary conveyor systems for further collecting objects or materials from the dedicated conveyor systems for transport to one or more locations. 
     
     
         13 . The method, according to  claim 1 , wherein the moving liquid comprises industrial fluids, human or animal food-grade fluids, pharmaceutical or biological fluids, stormwater, wastewater, combined sewer overflow, raw water, or industrial flows. 
     
     
         14 . The method, according to  claim 5 , wherein a first set has openings of approximately 1.0 inch and a second set has openings of approximately 0.125 inch. 
     
     
         15 . A system for collecting objects or materials from a conduit of liquid moving from upstream to downstream comprising:
 two sets of bar screen devices arranged in series by successively smaller openings, such that the bar screen set with the largest openings in the most upstream position and consists of four bar screen devices and the bar screen set with the smallest openings is in the most downstream position and consists of six bar screen devices;   at least one screen scraper apparatus for automatically cleaning each bar screen device;   a conveyor system dedicated to receiving and transporting objects or materials collected from each bar screen by a screen scraper to a collection area; and   at least one container at each collection area for receiving objects or materials from each conveyor system.   
     
     
         16 . The system, according to  claim 15 , further comprising at least one subsidiary conveyor system for receiving objects or materials, from each dedicated conveyor system, for transport to one or more collection areas.