Application of water jet assisted drag bit and pick cutter for the cutting of coal measure rocks. Final technical report. [Tests of combination in different rocks]

Technical Report · Tue Apr 01 04:00:00 EST 1980

DOI:https://doi.org/10.2172/7049656· OSTI ID:7049656

Ropchan, D; Wang, F D; Wolgamott, J

A laboratory investigation was made of the effects of high pressure water jets on the cutting forces of drag bit cutters in sedimentary rocks. A hard and soft sandstone, shale and limestone were tested with commercially obtainable conical and plow type drag bits on the EMI linear cutting machine. About 1200 cuts were made at different bit penetration, jet orientation, and water pressure to determine the reduction of cutting forces on the bit from the use of the water jet. Both independent and interactive cutting was used. The greatest reduction in cutting forces were with both of the sandstones; the drag forces were reduced about 30 percent and the normal forces about 60 percent at 5000 psi water pressure with the nozzle behind the bit. The method was less effective in the shale, except at 10,000 psi water pressure the reduction in drag force was about 55 percent. Of the rocks tested, the limestone was least affected by the water jet. The cutting forces for the plow bit showed continuous change with wear so a machined conical bit was used for most of the testing. Tests with the plow bit did show a large reduction in cutting forces by using the water jet with worn bits. An economic analysis of equipping a drag bit tunnel boring machine indicated that the water jet system could reduce costs per foot in sandstone by up to 40 percent.

• Research Organization: Colorado School of Mines, Golden (USA). Evacuation Engineering and Earth Mechanics Inst.
• DOE Contract Number: FG01-77ET12463
• OSTI ID: 7049656
• Report Number(s): DOE/ET/12463-1
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
012000* -- Coal
Lignite
& Peat-- Mining
42 ENGINEERING
420206 -- Engineering-- Mining & Drilling Equipment & Facilities-- (1980-1989)
COAL MINING
COMPARATIVE EVALUATIONS
CUTTING TOOLS
DATA
EQUIPMENT
EXPERIMENTAL DATA
HYDRAULIC MINING
HYDROGEN COMPOUNDS
INFORMATION
JETS
MINING
MINING EQUIPMENT
NUMERICAL DATA
OXYGEN COMPOUNDS
ROCKS
TOOLS
UNDERGROUND MINING
WATER