Crane-mounted drill and method for in-situ treatment of contaminated soil

Apparatus for in-situ treatment of contaminated soil that includes:

• an elongated hollow drive shaft, means for rotating said shaft about its axis while supporting said shaft in desired orientation, means coupled to said shaft for selectively injecting fluid under pressure into said shaft, drill means affixed to a lower end of said shaft for drilling a hole downwardly through the soil, and nozzle means on said drill means coupled to said shaft for injecting fluid from said shaft into the soil;
• characterized in that said fluid-injecting means comprises:
• first sensing means coupled to said shaft for providing a first electrical signal as a function of velocity of said shaft,
• valve means responsive to an electronic control signal for controlling flow of fluid to said shaft, and
• electronic control means responsive to said first electrical signal for providing said control signal so as to control injection of fluid into said drive shaft as a predetermined function of velocity of said shaft so as to achieve substantially uniform injection per unit of volume of drilled soil.

A method for in-situ treatment of contaminated soil that includes the steps of:

• (a) rotating a drill bit about its axis into the soil, and (b) injecting soil treatment fluid into the soil through the drill bit as the drill bit is rotating;
• characterized in that said step (b) comprises the steps of:
• (c) measuring axial velocity of said drill bit within the soil, and
• (d) controlling rate of fluid injection as a function of such axial velocity so as to achieve substantially uniform fluid injection per unit volume of drilled soil.

Apparatus for in-situ treatment of contaminated soil that includes:

• an elongated hollow drive shaft, means for rotating said shaft about its axis while supporting said shaft in desired orientation, means coupled to said shaft for selectively injecting fluid under pressure into said shaft, and drill means affixed to a lower end of said shaft for drilling a hole downwardly through soil;
• characterized in that said drill means comprises:
• a hollow sleeve mounted to said lower end of said shaft and extending therefrom coaxially with said shaft,
• a pair of drill blades cantilevered from said sleeve and extending radially outwardly therefrom diametrically opposite each other, said blades being of identical uniform cross-section and length,
• a plurality of radially spaced drill teeth oriented tangentially of said sleeve along one radial edge of each said blade, said teeth being angulated downwardly with respect to said sleeve,
• a hollow pipe on each said blade extending along a radial edge of said blade opposite said one edge, each said pipe opening into said sleeve for receiving fluid from said sleeve and said shaft, and
• a plurality of nozzle means on each said pipe opening tangentially of said sleeve oppositely of said teeth, said pluralities of nozzle means being identically oriented and positioned on each said pipe, said nozzle means being positioned at non-uniform radial spacing on each said pipe spaced from each other by decreasing distances radially outwardly of each said pipe.