Other

Methane Drainage Ventures

Carel J Brest Van Kempen

Robert M Sweet

Anil Mahyera

Amber C Davidson

Means and method for improving productivity and quality of grouted rock bolt installations. The invention provides means of automatically installing full length grouted bolts as well as tensioned (point anchor) grouted bolts, which ensures proper shredding of the grout package, proper mixing and proper curing of the grout, and minimizing machine time involvement. The invention also makes it possible to include a test for quality on each grouted bolt installed, within the automatic installation cycle. The invented means further allows control of the depth of holes drilled for rock bolting and automatic freeing of drill steels, where they may be danger of drill steel binding during drilling for rock bolting.

Method for automatically installing and testing grouted rock bolts

A gas-liquid-solids separation system for use with a drilling device includes a surge tank for holding drilling efflux comprising gas, liquid and solids, and adapted for mounting on a drilling device in a position for having a drill shaft extending therethrough. A stuffing box attached to a back side of the surge tank means and configured for enabling passage of the drill shaft therethrough prevents the drilling efflux from escaping the surge tank. A flange attached to the front side of the surge tank and aligned with the stuffing box for allowing passage of the drill shaft therethrough provides a seal between the surge tank and a borehole casing to enable the drilling efflux to flow into the surge tank means. An agitator disposed within the surge tank maintains suspension of the solids within the liquid, and a gas cyclone in fluid communication with the surge tank withdraws gas from the surge tank and separates any entrained liquid therefrom. The liquid and solids suspended therein are transferred to a slurry cyclone for separation and thereafter the liquid is stored in a tank for subsequent reuse as a cutting fluid.

Gas-liquid-solids separation system

A self-aligning stuffing box for use with a drilling device having a rotatable drill shaft includes a packing gland having an opening therethrough sized for passage of the rotatable drill shaft and includes packing rings for forming a seal between the packing gland and the drill shaft. A generally spherical exterior surface on the packing gland is supported by an interior spherical surface of a socket in a ball-and-socket like manner to enable the packing gland, packing rings and the rotatable drill shaft to pivot about the longitudinal axis of the rotatable drill shaft together. A frame slidably supports the socket and enables the socket, packing gland and packing ring means and rotatable drill shaft to be laterally displaced, with respect to the longitudinal axis of the drill shaft, as a single unit, in order to prevent damage to the packing rings by vibrational movement of the drill shaft during drilling.

Self-aligning stuffing box

A method for controlling parametric variations in processes where one variable is subject to an exponential change with time. One application is particulary advantageous in underground mine roof bolting using mechanical anchors where a device utilizing the method can be employed to install mine roof bolts at varying initial tensions in such a manner that the bolt tensions found among a population of roof bolts converge to one tension value within one or two hours after installation due to individual differences in tension decay rate. Since roof bolt tension decay bears an exponential relationship to time, variability in bolt tension which develops after mentioned convergence has taken place is small for a long period of time, in marked contrast to a conventional installaton which is characterized by bolt tension variability which grows rapidly into a far wider range immediately after installation. An extension of said mine roof bolting application further allows an exact assessment of mine roof movements using the roof bolts themselves. A device embodying the invention in mine roof bolting as described, senses the roof bolt tension decay rate during the installation process and automatically tensions the roof bolt to a value appropriate to achieve tension convergence as described.

Device and method for controlling time dependent parameter variability

A method for controlling parametric variations in processes where one variable is subject to an exponential change with time. One application is particularly advantageous in underground mine roof bolting using mechanical anchors where a device utilizing the method can be employed to install mine roof bolts at varying initial tensions in such a manner that the bolt tensions found among a population of roof bolts converge to one tension value within one or two hours after installation due to individual differences in tension decay rate. Since roof bolt tension decay bears an exponential relationship to time, variability in bolt tension which develops after mentioned convergence has taken place is small for a long period of time, in marked contrast to a conventional installation which is characterized by bolt tension variability which grows rapidly into a far wider range immediately after installation. An extension of said mine roof bolting application further allows an exact assessment of mine roof movements using the roof bolts themselves. A device embodying the invention in mine roof bolting as described, senses the roof bolt tension decay rate during the installation process and automatically tensions the roof bolt to a value appropriate to achieve tension convergence as described.

A device and method for determining compressive strength of solid matter in situ. One embodiment is particularly advantageous in underground mine roof bolting, where the device can be used to indicate the compressive strength of the rock immediately surrounding the roof bolt anchor. Such compressive strength indication is developed for each bolt installed as it is installed using no machine operator time or effort beyond the time and effort normally used already. The compressive strength indication is developed by monitoring rate of bolt head torque increase with respect to bolt head rotation and relating these to anchor tooth penetration parameters and hence rock compressive strength.

Growing community of inventors

Salt Lake City, UT, United States of America

Carel J Brest Van Kempen