US 4,576,572 A · Apparatus and method for cleaning contaminated soil

Abstract

Apparatus and method for effecting thermal reclamation of granular materials, particularly foundry sand and contaminated soil. In a first embodiment, a sand calciner system (10) includes a refractory-lined drum (12) mounted for oscillation about its longitudinal axis (14). An arrangement of plows (76) are provided along the bottom inside of the drum (12) for mixing the sand received through an inlet (54) and advancing it toward a discharge outlet (56) responsive to oscillation of the drum over a predetermined arc about the axis (14). The plows (76) are arranged in staggered rows with each plow having a transverse front surface facing the inlet (54), an inclined top surface, and an angled back surface facing the outlet (56). An aerator pipe (78) is provided in conjunction with the plows (76) to fluidize the sand and thereby effect more thorough mixing and exposure to burners (58) positioned along the upper side of the drum (12) for complete calcining. A tempering section (16) and screening section (18) are preferably connected to the discharge end of the drum (12) to pre-cool the calcined sand and then classify it for further handling and reuse in foundry cores and molds or the like. In a second embodiment, the system (130) is particularly adapted for cleaning soil contaminated with pentachlorophenol, creosote, oil, fuel or other hydrocarbon-rich liquids.

Claims15

Dependent claims

Apparatus for effecting thermal reclamation of contaminated soil or other granular material comprising:

an elongate drum having a longitudinal axis, a generally cylindrical side, and opposite generally circular closed ends;
means defining a material inlet in one end of said drum;
means defining a material outlet in the other end of said drum;
an internal liner of refractory material on the side and ends of said drum;
means for supporting said drum for at least partial rotation about its longitudinal axis;
means for effecting oscillation of said drum over a predetermined arc about its longitudinal axis;
a plurality of burners located at longitudinally spaced, staggered intervals in the side of said drum for heating the interior of the drum sufficiently to incinerate any hydrocarbons in the material;
a plurality of plows located at longitudinally spaced-apart intervals on said refractory liner and between the ends of said drum, said plows being arranged in staggered rows with each plow having a generally transverse front surface facing the material inlet, an inclined top surface, and an angled back surface facing the material outlet, for mixing the material for maximum exposure to said burners while advancing the material toward the material outlet responsive to oscillation of said drum;
and
an aerator pipe associated with said plows for injecting air into the material to facilitate mixing and advancing thereof, and for adding combustion air to facilitate thorough thermal reclamation of material in said drum.

7 more elements

Apparatus for effecting thermal reclamation of contaminated soil, which comprises:

an elongate, refractory-lined drum having a longitudinal axis, a generally cylindrical side, and opposite generally circular closed ends;
means defining a material inlet in one end of said drums;
an excess combustion air fan fluidly connected to said material inlet;
means defining a material outlet in the other end of said drum;
means for supporting said drum for at least partial rotation about its longitudinal axis;
means for effecting oscillation of said drum over a predetermined arc about its longitudinal axis;
a plurality of burners located at longitudinally spaced, staggered intervals in the side of said drum;
a plurality of temperature sensors located at longitudinally spaced intervals in the side of said drum for monitoring the temperature therein;
and
indexing structure located inside said drum opposite said burners for mixing the soil for maximum exposure to said burners to incinerate any hydrocarbons therein, and for advancing the soil from the inlet to the outlet responsive to oscillation of said drum.

7 more elements

Dependencies are inferred from the claim text.

Apparatus and method for cleaning contaminated soil

Life of this patent

Apparatus and method for cleaning contaminated soil

Life of this patent

Abstract

Claims15