THERMOCORER FOR RAPID DRILLING TUNNELING AND EXCAVATING

The potential of drilling bore-holes and tunnels by the dynamic kerf-melting technique is investigated. This technique, Thermocoring, uses an electrically heated tubular screw pump attached to a radially slotted annular flat drill-head, which resembles a shell end-mill with slot jets. The rotating screw heats and pumps the viscous lava through the drill-head. Experiments have demonstrated concept feasibility by dynamic kerf-melting 2 in. diameter holes in low-melting-temperature, non-spallable rock simulants, such as solidified glycerin and fuzed salt, using inexpensive steel components. Advance rates of 2500 ft/hr in solid hard salt were recently achieved using pumped molten salt, super-heated to 200C above its melting temperature. As a result, a new mechanism of melt drilling is hypothesized having measured energy requirements one-tenth those of direct bulk melting and offering the potential for advance rates in earth-strata far beyond present technology, with concomitant cost savings. As a result, Thermocoring may offer solutions to many of mankind's most urgent earth-centered ecological, scientific, raw material and energy supply problems.

  • Corporate Authors:

    Energy Research and Generation, Incorporated

    Lowell and 57th Street
    Oakland, CA  USA  94608

    National Science Foundation

    Research Applied to National Needs
    Washington, DC  USA  20550
  • Authors:
    • Benson, G M
  • Publication Date: 1976-7

Media Info

  • Pagination: 125 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00159262
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: NSF-RA-760483
  • Contract Numbers: NSF-GI-43100
  • Files: TRIS
  • Created Date: Aug 31 1977 12:00AM