US 5,050,386 A · Method and apparatus for containment of hazardous material migration in the earth

Abstract

A method and system is disclosed for reversibly establishing a closed, flow-impervious cryogenic barrier about a predetermined volume extending downward from a containment site on the surface of the Earth. An array of barrier boreholes extend downward from spaced apart locations on the periphery of the containment site. A flow of a refrigerant medium is established in the barrier boreholes whereby water in the portions of the Earth adjacent to the barrier boreholes freezes to establish ice columns extending radially about the boreholes. The lateral separations of the boreholes and the radii of the ice columns are selected so that adjacent ice columns overlap. The overlapping ice columns collectively establish a closed, flow-impervious barrier about the predetermined volume underlying the containment site. The system may detect and correct potential breaches due to thermal, geophysical, or chemical invasions. Also disclosed are a method and apparatus for reversibly freezing a predetermined volume extending downward from a containment site on the surface of the Earth and for establishing and removing cells within that volume. An array of heat transfer devices is established in a stick-like fashion in the volume for systematically freezing and unfreezing portions of the Earth adjacent to the heat transfer devices. One embodiment of the disclosed heat transfer devices includes at least one heat transfer rod extending radially outwardly from the heat transfer device into the predetermined volume for establishing a horizontal layer of frozen earth beneath the containment site.

Claims24

Dependent claims

A method for reversibly freezing a predetermined volume extending downward beneath a surface region of the Earth, and for establishing, and removing at least one substantially frustum-shaped cell extending downward from said surface region and within said volume, the method comprising the steps of:

A. establishing an array of elongated heat transfer devices extending downward from spaced-apart locations throughout said surface region, said array including a first subset of said devices positioned on the lateral surfaces of said cell, and including a second subset of said devices positioned at least within said cell,
B. establishing a relatively low temperature on the outer surface of said heat transfer devices of said second set, whereby the water in the portions of the Earth adjacent to said heat transfer devices of said second set freezes to establish ice columns extending axially along and radially bout the central axes of said heat transfer devices of said second set, wherein the position of said central axes, the radii of said columns, and the lateral separations of said heat transfer devices of said second set are selected so that adjacent columns overlap, said overlapping columns collectively filling at least the periphery of said cell to establish a frozen volume substantially containing at least the Earth therein,
C. establishing a relatively high temperature on the surface of said heat transfer devices of said first set, whereby the water in the portions of the Earth adjacent to said heat transfer devices of said first set and along the lateral surfaces of said cell is substantially unfrozen, said unfrozen portions of the Earth defining the lateral surfaces of said cell,
D. removing said cell from said volume by lifting said cell from its in situ position in said volume.

1 more element

A. establishing an array of elongated heat transfer devices extending downward from spaced-apart locations throughout said surface region, said array including a first subset of said devices positioned on the lateral surfaces of said cell, and including a second subset of said devices positioned at least within said cell,
B. establishing a relatively low temperature on the outer surface of said heat transfer devices of said second set, to establish low temperature columns of earth which extend axially along and radially about the central axes of said heat transfer devices of said second set, wherein the position of said central axes, the radii of said columns, and the lateral separations of said heat transfer devices of said second set are selected so that adjacent low temperature columns overlap, said overlapping low temperature columns collectively filling at least the periphery of said cell to establish a low temperature composite volume of earth therein,
C. injecting water into selected portions of the Earth adjacent to said second subset of heat transfer devices resulting in a frozen volume of earth being established at least at the periphery of said cell;
D. establishing a relatively high temperature on the surface of said heat transfer devices of said first set, whereby the water in the portions of the Earth adjacent to said heat transfer devices of said first set and along the lateral surfaces of said cell is substantially unfrozen, said unfrozen portions of the Earth defining the lateral surfaces of said cell,
E. removing said cell from said volume by lifting said cell from its in situ position in said volume.

2 more elements

An Earth-freezing apparatus comprising:

A. a relatively high thermal conductivity, elongated tubular element extending along a reference axis and having a relatively high thermal conductivity, solid central core within said tubular element, said tubular element and central core both having a proximal end and a distal end,
B. a continuous central channel extending within said central core from said proximal end to a point near said distal end and from said point to said proximal end, said central channel being adapted to accommodate a flow of a heat exchange fluid therethrough,
C. at least one substantially uniform cross-section heat transfer rod guide channel extending within said central core from said proximal end to an exit point between said proximal end and said distal end, said guide channel extending along a guide axis, said guide axis being substantially parallel to said reference axis at said proximal end and being angularly offset with respect to said reference axis at said exit point, whereby the walls of said channel are adapted to receive an elongated metal rod inserted from said proximal end and driven therethrough along said guide axis, whereby the leading tip of said rod exits in part from said core at said exit point.

Dependencies are inferred from the claim text.

Method and apparatus for containment of hazardous material migration in the earth

Life of this patent

Method and apparatus for containment of hazardous material migration in the earth

Life of this patent

Abstract

Claims24