The design of rigs for drilling a fan of underground boreholes is at present lacking in sound foundations, owing to the absence of a method for estimating their productivity and of assessing how this index depends on the constructional elements of the equipment.On the basis of a study of the drilling process and the preparatory and finishing operations of the NKR-100M, KS-50, and S13[J-70 drill rigs and the experimental BU-1V model, using the method in [1] we have analyzed the factors governing their productivities. As a result of this investigation we suggest an equation for the productivity per shift of the drill rig [2], which enables us to determine in advance the effectiveness of technical measures or research work aimed at increasing the productivity of the rigs:where 1I is the depth of the borehole in meters, L is the effective length of the drill pipe in meters, lc is the length of the drill pipe couplings in meters, l r0 is the optimum travel of the boring bit before regrinding, in meters, V d is the mechanical drilling speed in meters per minute, V m is the speed at which the boring bit is manuevcred in meters per minute, V i is the idling speed of the boring bit in meters per minute, t b is the time to replace one bit in minutes, n is the number of bits expended on the borehole before their first regrinding, tf is the time to rotate the frame by the angle between the boreholes, in minutes, t d is the drilling time in minutes, t c is the time for resetting the rig to a new fan of boreholes, in minutes, tf is the time for transporting (flitting) the rig to a new fan of boreholes, in minutes, k is the number of boreholes in each fan, t o is the total time taken to build up or disas-~ .5 g I '}7 ~_~.
The possibilities of obtaining porous permeable cermet SHS-materials with catalytic properties are studied. The mixture consisted of powders of steel alloy scale, concentrate of ilmenite, oxides of aluminum or chromium, the basis of the material formed the backbone of metal ceramics (Al2O3) and reduced iron, as well as additives of metal oxides. The resulting material is intended for the catalytic purification of exhaust gases of diesel engines, in particular, from nitrous oxide, carbon monoxide and soot.