New high performance product from Driltech Inc.
Driltech's goal was to provide one specialized drill to replace two drills, to effectively better utilize the drilling operation. Ultimately, by providing a new highly mobile drill the overall cost per foot of drilling would be reduced. The key to a successful drill would be the ability to cover a wide range of drilling conditions and achieve higher production rates.
As part of the feasibility study, Driltech analyzed the various overburden depths and the corresponding percentages. By doing so they could target a single pass depth which would produce the best results in terms of productivity. Driltech found in one case that 65% of the drilling was 55 feet or less, 32% was to 105 feet, and the remaining 3% was over 105 feet. Driltech's experience had proven that the most cost effective method of drilling was single pass, which could result in a 20 - 25% increase in productivity, due to the elimination of drill pipe changes.
Driltech came to the conclusion that the greatest cost reduction could be achieved from a 9 7/8" to 10 5/8" highly mobile drill with a single pass capability of 55 feet. However, to achieve the utilization goal, one additional feature was required, a total depth capability of 105 feet. This presented a problem, because no 10 5/8", 130,000 lb. drill with the required specifications was available now in the drilling industry. Products were available which could provide the single pass and total depth requirement, but their cost and weight was nearly double of that which the application required.
In the months that followed, Driltech Inc. began a project to compose a specification and design a new product. Very strict criteria was written, which included a hole size of 9 7/8" to 10 5/8", single pass depth of 55 feet, a total depth of 105 feet, and a minimum hole bailing velocity of 6,200 feet per minute, all the while maintaining good machine stability. Driltech analyzed the requirements and came to the conclusion that the specification could be fulfilled and all of the expectations achieved.
Design work began on the D55SP in March of 1993 and was completed in October 1993. Driltech drew from the experience accumulated on the D75KS and D60KS drills, of which over 100 drills are in operation around the world. The results revealed a product mounted on a D75KS chassis for stability and strength, with a newly designed mast structure and pulldown system. The combination of the two provided all of the requirements expected and more.
The D55SP is equipped to deliver 55,000 lbs. of bit load, 2000 cfm of air, 55 foot single pass and has a two position drill pipe loader which extends the drilling depth to 105 feet. No other drill of its size has accomplished all of these aspects while maintaining stability until now. In addition, to improve productivity the D55SP was equipped with a pulldown system which has the fastest feed and retract rates of any drill in its class. These rates coupled with a high performance 180 hp rotary head set to deliver 150 rpm at 6,300 foot pounds of torque, assure improved penetration.
The D55SP was delivered in December of 1993 and drilled its first production holes in January of 1994. The first six months have proven the drill design concept, through its productivity. The D55SP is averaging over 1000 feet per shift, while drilling a 10 5/8" hole, 30% better than required. As for the availability of the D55SP, from January through the month of June the drill has averaged 87% mechanical availability, proving the reliability of the D75KS was carded to the D55SP. In addition the 19' 6" long track base provides excellent stability in all types of bench conditions. Overall, the result has been a measurable improvement in drilling costs of 66% over the previous cost per foot. In the final analysis, the D55SP has clearly proven the design goals of the project.
The D55SP is an excellent example of how close cooperation between mining companies and manufacturers can result in new products which improve production and ultimately lower mining costs. In the case of the D55SP, it has a wide range of applications in multi seam coal and hard rock mines. Undoubtedly the D55SP will have a bright future in the Driltech product line, and will prove to be one of the most productive drills in the industry.
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|Title Annotation:||Company Profiles; D55SP mobile drill|
|Publication:||E&MJ - Engineering & Mining Journal|
|Date:||Aug 1, 1994|
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