System for treating drilling mud containing potassium chloride (KCl) for disposal

Claim 1

A method for treating an aqueous slurry of used drilling mud containing salt and clay in a rotating tube forming a bore having first and second ends, comprising: projecting at least one open flame part way down the bore from its second end and producing therefrom a flow of hot combustion gas that moves through the bore and is exhausted from the bore adjacent its first end; introducing the slurry into the bore at its first end; advancing the slurry through the bore until it reaches flame while simultaneously cascading it during such advance, so that the slurry moves countercurrently to the flow of hot combustion gas, is directly heated thereby and water is evaporated from the slurry to leave a mud residue in the form of discrete lumps which retain therein most of the salt; further advancing the mud residue lumps while contacting them with the flame to convert said lumps into dried pellets that retain the salt and are more cohesive and resistant to water breakdown than the lumps; and discharging the pellets from the second end of the bore.

Claim 2

A method for treating an aqueous slurry of used drilling mud containing salt and clay in a rotating tube forming a bore having first and second ends, comprising: projecting at least one open flame part way down the bore from its second end and producing therefrom a flow of hot combustion gas that moves through the bore and is exhausted from the bore adjacent its first end; introducing the slurry into the bore at its first end; advancing the slurry through the bore until it reaches flame while simultaneously cascading it during such advance, so that the slurry moves countercurrently to the flow of hot combustion gas, is directly heated thereby and water is evaporated from the slurry to leave a mud residue in the form of discrete lumps which retain therein most of the salt; further advancing the mud residue lumps while contacting them with the flame to convert said lumps into dried pellets that retain the salt and are more cohesive and resistant to water breakdown than the lumps; and discharging the pellets from the second end of the bore.

Claim 4

A method for treating an aqueous slurry of used drilling mud containing salt and clay in a rotating tube having an inside surface forming a bore having first and second ends, comprising: projecting two open flames part way down the bore from its second end, one flame being positioned centrally of the bore and the other being positioned adjacent the lower portion of the inside surface of the tube, and producing therefrom a flow of hot combustion gas that moves through the bore and is exhausted from the bore adjacent its first end; introducing the slurry into the bore at its first end: advancing the slurry through the bore until it reaches flame while simultaneously cascading it during such advance, so that the slurry moves countercurrently to the flow of hot combustion gas, is directly heated thereby and water is evaporated from the slurry to leave a mud residue in the form of discrete lumps which retain therein most of the salt; further advancing the mud residue lumps while contacting them with flame to convert the lumps into dried pellets that retain the salt and are more cohesive and resistant to water breakdown than the lumps; and discharging the pellets from the second end of the bore.

Claim 5

A method for treating an aqueous slurry of used drilling mud containing salt and clay in a rotating tube having an inside surface forming a bore having first and second ends, comprising: projecting two open flames part way down the bore from its second end, one flame being positioned centrally of the bore and the other being positioned adjacent the lower portion of the inside surface of the tube, and producing therefrom a flow of hot combustion gas that moves through the bore and is exhausted from the bore adjacent its first end; introducing the slurry into the bore at its first end: advancing the slurry through the bore until it reaches flame while simultaneously cascading it during such advance, so that the slurry moves countercurrently to the flow of hot combustion gas, is directly heated thereby and water is evaporated from the slurry to leave a mud residue in the form of discrete lumps which retain therein most of the salt; further advancing the mud residue lumps while contacting them with flame to convert the lumps into dried pellets that retain the salt and are more cohesive and resistant to water breakdown than the lumps; and discharging the pellets from the second end of the bore.