Sludge extraction apparatus and method

Abstract

There is provided sludge extraction apparatus ( 10 ) including a collection pipe ( 13 ) having a plurality of spaced, a suction pump ( 23 ), a suction pipe ( 15 ) with an end connected to the suction pump ( 23 ) and a suction head assembly ( 16 ) connected to the other end and slidable through the collection pipe ( 13 ) from an end, the suction head assembly ( 16 ) including a leading body portion ( 17 ) spaced from and connected to a trailing body portion ( 21 ) having an axial bore ( 19 ) connected to a suction pipe ( 15 ), the leading ( 17 ) and trailing ( 21 ) body portions substantially occluding the collection pipe ( 13 ) in use and defining there between a suction zone ( 22 ) of a length selected to open to at least one said opening at selected positions of the suction head assembly along the collection pipe.

1 . Sludge extraction apparatus including:
 a collection pipe having a plurality of openings through the wall thereof at selected spacings;   a suction pump;   a suction pipe having one end connected to the suction pump;   a suction head assembly connected to the other end of the suction pipe and slidable through the collection pipe from one end thereof, the suction head assembly including a leading body portion spaced from and connected to a trailing body portion having an axial bore connected to a suction pipe, the leading and trailing body portions substantially occluding the collection pipe in use and defining therebetween a suction zone of a length selected to open to at least one said opening at selected positions of the suction head assembly along said collection pipe.   
     
     
         2 . Sludge extraction apparatus according to  claim 1 , wherein the collection pipe is of a polymer material or composite thereof. 
     
     
         3 . Sludge extraction apparatus according to  claim 2 , wherein the polymer is HDPE. 
     
     
         4 . Sludge extraction apparatus according to  claim 1 , wherein the apertures are selected from single apertures spaced in a line along the pipe and apertures arranged in groups around the pipe with the groups spaced along the pipe. 
     
     
         5 . Sludge extraction apparatus according to  claim 4 , wherein the apertures are in groups and the apertures are elongate in the direction of the pipe axis to preserve cross section for a given aperture area. 
     
     
         6 . Sludge extraction apparatus according to  claim 1 , wherein the collection pipe is permanently installed in a sludge pond or pit. 
     
     
         7 . Sludge extraction apparatus according to  claim 1 , wherein the collection pipe is relocatable in a sludge pond or pit. 
     
     
         8 . Sludge extraction apparatus according to  claim 1 , wherein the selected spacing of the apertures comprises even spacing. 
     
     
         9 . Sludge extraction apparatus according to  claim 1 , wherein the suction pump is selected from positive displacement pumps. 
     
     
         10 . Sludge extraction apparatus according to  claim 1 , wherein the suction pump is a compressed air operated venturi vacuum/pressure cycle pump. 
     
     
         11 . Sludge extraction apparatus according to  claim 1 , wherein the suction pump is mobile or transportable. 
     
     
         12 . Sludge extraction apparatus according to  claim 1 , wherein the suction pipe is formed of polymer or polymer composite. 
     
     
         13 . Sludge extraction apparatus according to  claim 1 , wherein the connection of the suction pipe to the suction pump is a rotating coupling to the suction pump associated with a spooler, whereby the suction pipe may be spooled on and off the spooler. 
     
     
         14 . Sludge extraction apparatus according to  claim 13 , wherein the spooler is co-mounted with the suction pump to form a transportable assembly. 
     
     
         15 . Sludge extraction apparatus according to  claim 1 , wherein the suction head assembly runs at a working clearance in to bore while maintaining a substantial occlusion to the bore of the pipe separating the suction zone from the collection pipe upstream and downstream of the suction head assembly. 
     
     
         16 . Sludge extraction apparatus according to  claim 1 , wherein the leading and trailing body portions are each of plastic construction selected from cast resin, thermoplastic moulding, and a free-machining polymer. 
     
     
         17 . Sludge extraction apparatus according to  claim 1 , wherein the leading body portion is spaced from the trailing body portion by being integrally formed with interconnecting web portions. 
     
     
         18 . Sludge extraction apparatus according to  claim 1 , wherein the leading body portion and the trailing body portion comprise respective leading and trailing members spaced apart and interconnected by one or more interconnecting strut members. 
     
     
         19 . Sludge extraction apparatus according to  claim 1 , wherein there is provided an equalization port passing through the leading body portion and connecting the suction zone to the collection pipe ahead of the suction head assembly. 
     
     
         20 . Sludge extraction apparatus according to  claim 19 , wherein the port is a substantially axial equalization port between the suction zone and the collection pipe ahead of the suction head assembly. 
     
     
         21 . Sludge extraction method including the steps of:
 installing into the bottom of a settling pit, pond or the like a collection pipe having a plurality of openings through the wall thereof at selected spacings;   connecting a suction pump to one end of a suction pipe;   connecting a suction head assembly including a leading body portion spaced from and secured to a trailing body portion to the other end of the suction pipe by an axial bore through the trailing body portion;   inserting the suction head assembly into an open end of the collection pipe, whereby the leading and trailing body portions substantially occlude the collection pipe and define a suction zone therebetween of a length selected to open to at least one said opening at substantially all positions along said collection pipe; and   moving said suction head assembly through the bore of said collection pipe while operating said suction pump to draw sequentially through said openings.