DRILLING: WHAT”S NEW WATER-JET DRILLS

With financial assistance from the National Research Council, a small, publicly listed industrial research company in Toronto is aggressively pursuing Canada’s hard-rock drilling and bolting market. The company, Indescor Hydrodynamics, has built a water-jet- assisted drilling machine which it hopes to eventually produce on a commercial scale. Such a machine, which could conceivably be automated, probably will be marketed soon as an alternative to conventional pneumatic and electric/hydraulic rock-bolting machines already on the market. Dr Richard Puchala is director of research and development for Indescor. He says the economics of cutting slots in rock with water jets was proven by his company last fall in a granite quarry in Quebec (see “Goodbye Bits and Steel” in our September, 1987, issue). Indescor is already marketing machines that demolish concrete in underground parking garages, again using high-pressure water. Proof that high-pressure water can be used to advantage for drilling holes in underground mines may be just around the corner. Once perfected, such a drill will be quiet, will have relatively small reaction forces and will produce little vibration or dust.

Initial test results from Indescor’s plant in Concord, Ont., have been encouraging, but Murphy’s Law reduced test pressures to a minimum in the early stages of the test. “A seal, imported from the U.S., failed in the early stages of the tests,” Puchala says,”so we’ve been unable to use pressures in excess of 20,000 lb per sq inch in our initial tests.” To increase the pressure of the water for future tests, Indescor has assembled a hydraulic intensifier testing unit. It has the capacity to deliver water to the prototype drill at pressures that are three times as high as those used in initial test work. The testing unit consists of two McCartney intensifiers combined with two hydraulic power packs. Once the seal on the drill is replaced, this unit will be used to deliver water at a pressure of 60,000 lb per sq inch to the drill.

A total of 10 holes has been drilled in a block of black “Peribonka granite” by the prototype at pressures of 20,000 lb per sq inch. The maximum penetration rate was 80 cm per min, but Puchala would like to see penetration rates of 140 cm per min or better using the higher pressure water. Flow rates were about 18(us) gal per min at 20,000 lb per sq inch, but would be even lower at the higher pressures anticipated. “Although this technology is ideal for granite, the rock types in which the machine has hitherto been tested are not representative of the variety of ground conditions in underground mines,” Puchala explains. “The problem now is getting the money to continue the research. What should be accomplished next is co-operation between mining companies and the drill manufacturers.” Three New Craelius Drills

Craelius has introduced a new series of multi-purpose drill rigs. Called the Terramec 400, 600 and 1000, they can be used for auger, in-the-hole, coring and reverse circulation drilling.

The hydraulic rig, assembled in modular components, is available on either crawler or wheeled carriers. Accessories include numerous types of spindles, hydraulic winches and alternative-length drill masts. Pneumatic Drills

Sullair Corp. of Pittsburgh, Pa., has introduced a new m-series of pneumatic drills. Available in 30-, 40- and 50-lb weights, the drills are a part of the Maco-Meudon line, being distributed by Sullair.

Features include a dead man handle, which automatically stops the tool when the throttle lever is released, and a throttle latch to help prevent uncontrolled starting.

A variable throttle control allows stepless speed control for maximum production.

Any part that wears out during normal operation is covered by Sullair’s exclusive warranty. Portable Sonic Drill

Vi-Cor Technologies of Richmond, B.C., has introduced a high-performance, low-cost sampling system called Vibra Corer. cents

This portable sonic drill can advance up to 5 ft in 10 seconds in unconsolidated sediments and consistently recovers continuous, undisturbed, representative cores, Vi-Cor says.

Powered by an 8-hp Honda engine, the drill produces high-frequency sonic vibrations at a rate of 12,000 vibrations per minute. The vibrator effect, aided by the weight of the drill head and rods, is sufficient to penetrate a variety of unconsolidated formations. The drill head weighs 11.5 kg and the power pack weighs about 41 kg.

Samples can be viewed through a transparent liner, before capping the ends and shipping off to a lab.

Optional features include a portable pontoon platform for drilling in swampy areas. Surface Drill Rig

Atlas Copco has combined a large and powerful rock drill with a folding boom to drill several holes 35-76 mm in diameter from the same setup position.

The new rig is the ROC 612HC-01 all-hydraulic crawler drill. It is a one- man-operated rig. Three different impact stroke settings make the drill (the COP 1238LP) easily adaptable to different rock conditions and different types of steel.

An on-board compressor reduces set-up time, and good ground clearance and well-dimensioned chassis make it highly manoeuvrable, according to Atlas Copco. The folding boom with extended reach makes it practical to drill several holes without moving the rig. –30–