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  United States  94608

  National Science Foundation

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

Media Info

• Pagination: 125 p.

Subject/Index Terms

• TRT Terms: Boreholes; Cost effectiveness; Cutting; Drilling; Drilling machines; Excavation and tunneling; Field studies; Heat flux; Melting; Rock mechanics; Thermal properties; Tunnels
• Old TRIS Terms: Drilling equipment; Drilling methods; Kerf; Screw pumps; Tunnels /field measurements/
• Subject Areas: Bridges and other structures; Construction; Highways;

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