Auger cleaning of solids

Abstract

A system for cleaning particulate solids contaminated with hydrocarbons and water includes a preheating feed auger ( 12 ), a first separator ( 14 ) which comprises an auger ( 26 ) and a heat source, a first vapour collection and condensation system, a second separator ( 30 ) which comprises an auger ( 26 ) and a heat source which accepts the solids from the first separator and operates at a higher temperature, and a second vapour collection and condensation system. The system is particularly useful for cleaning solids obtained from drilling mud, which solids are mixed with water and diesel.

1 . An apparatus for cleaning particulate solids mixed with at least a first liquid and a second liquid, wherein the first and second liquids have different boiling points, said apparatus comprising: 
 (a) a first separator comprising: 
 i. an elongate cylindrical housing having an inlet and an outlet and defining a vapour collection opening;  
 ii. an augur rotatably disposed within the housing,  
 iii. means for heating the first separator;  
   (b) a second separator comprising: 
 i. an elongate cylindrical housing having an inlet and an oulet and defining a vapour collection opening;  
 ii. an augur disposed within the housing;  
 iii. means for heating the second separator;  
   (c) means for rotating the first and second augurs;    (d) a first vapour collector and condensor attached to the first housing for collecting and condensing vapour from the first separator; and    (e) a second vapour collector and condensor attached to the second housing for collecting and condensing vapour from the first separator;    wherein the outlet of the first separator is connected to the inlet of the second separator and the temperature of the first separator is maintained higher than the boiling point of the first liquid but lower than the boiling point of the second liquid and the temperature of the second separator is maintained higher than the boiling point of the second liquid.    
     
     
         2 . The apparatus of  claim 1  further comprising a feed augur for directing the solids to the inlet of the first separator, wherein the feed augur comprises heating means for preheating the solids.  
     
     
         3 . The apparatus of  claim 2  wherein the means for driving the first and second separators comprises at least one internal combustion motor.  
     
     
         4 . The apparatus of  claim 2  wherein the means for driving the first and second separators comprises at least one electric motor.  
     
     
         5 . The apparatus of  claim 4  further comprising an internal combustion motor driving an electric generator, wherein the electricity generated is used to drive the at least one electric motor, and wherein the internal combustion motor exhaust is used to heat one of or a combination of the feed augur, first separator and second separator.  
     
     
         6 . The apparatus of  claim 1  wherein the first separator augur and the second separator augur each comprise a discontinuous section at one end of the augur adjacent the separator outlet, and wherein each of the first and second separators comprise a weir adjacent the separator outlet.  
     
     
         7 . The apparatus of  claim 5  wherein the one or both of the first augur and the second augur comprise a hollow shaft and the internal combustion motor exhaust is directed through one or both of the hollow shafts.  
     
     
         8 . An apparatus for treating solids mixed with a first liquid and a second liquid, wherein the first and second liquids have different boiling points, said apparatus comprising: 
 (a) first and second separators each comprising: 
 i. an elongate cylindrical housing having an inlet and an outlet and defining a vapour collection outlet;  
 ii. an augur disposed within the housing, said augur having a discontinuous section near the outlet comprising solids churning means;  
 iii. means for heating the first separator;  
   (b) means for driving each of the first and second separators;    wherein the outlet of the first separator is connected to the inlet of the second separator.    
     
     
         9 . The apparatus of  claim 8  further comprising a preheater connected to the inlet of the first separator for heating the solids and liquids mixture.  
     
     
         10 . The apparatus of  claim 9  wherein the preheater comprises a heated feed auger.  
     
     
         11 . The apparatus of  claim 8  wherein the first and second solids churning means comprises a plurality of pins extending radially outward from the augur shaft.  
     
     
         12 . The apparatus of  claim 11  wherein the first and second solids churning means further comprises a plurality of planar scrapers disposed on the outer ends of the pins.  
     
     
         13 . The apparatus of  claim 8  wherein the first separator comprises an intake restriction plate which limits the entry rate of solids into the first separator.  
     
     
         14 . The apparatus of  claim 8  wherein the first separator is maintained at a temperature higher than the boiling point of the first liquid but less than the boiling point of the second liquid and the second separator is maintained at a temperature higher than the boiling point of the second liquid.  
     
     
         15 . The apparatus of  claim 8  further comprising first means for collecting and condensing vapour generated by the first separator and second means for collecting and condensing vapour generated by the second separator.  
     
     
         16 . The apparatus of  claim 15  wherein the first and second condensation means each comprise means for cooling the condensate and spraying the condensate into the incoming vapour stream.  
     
     
         17 . A method of cleaning particulate solids mixed with first and second liquids having different boiling points, comprising the steps of: 
 (a) passing the solids through a first augur separator heated to temperature greater than the first boiling point but less than the second boiling point;    (b) collecting and condensing the vapours from the first augur separator;    (c) passing the solids through a second augur separator heated to a temperature greater than the second boiling point; and    (d) collecting and condensing the vapours from the second augur separator; and    (e) recovering the clean, dried solids.