A steel structure that revolves a mine car and discharges the contents,
usually sideways, into a bunker or onto a screen. Nelson
Earth-moving machine with vertical wheel that carries digging buckets
peripherally. These loosen soil and deliver to short conveyor loader, the
assembly being mounted on crawler track. Capacity up to 5,000 st/h (4,500
t/h). Also called bucket wheel excavator. Pryor, 3
See:rotational fault
a. A feeder comprising a horizontal rotating circular plate mounted under
the mouth of a hopper and arranged with an adjustable plow to control the
rate of flow of material over the edge of the plate. BS, 5
b. See:disk feeder
Horizontally mounted cylinder rotating between trunnions through which gas
or oil flame is introduced. Pryor, 3
A drilling machine that operates as a purely rotary machine to which is
added a percussive action. The specially designed rotary-percussive
drilling bit not only gives a greater penetration rate, but is also able
to operate longer without deterioration of the cutting edges. A
disadvantage is the great size of the air-operated machine, which is
usually mounted on a carriage. Nelson
A method of drilling in which repeated blows are applied to the bit, which
is continually rotated under power. BS, 12
A positive-displacement pump in which the liquid-propelling parts are
cams, gears, impeller wheels, etc., rotating within a case, as
distinguished from those pumps that move liquids by means of the
to-and-fro motion of a piston within a cylinder. CF:centrifugal pump
Long
a. A screen for sizing aggregate and similar material; it is a pierced
rectangular plate bent into a cylinder. Hammond
b. See:trommel
a. Any rotary drill used to drill blastholes. Long
b. See:seismograph drill
Any of the cylindrical smelters that depend on slow rotation about a
horizontal axis for agitation of the molten mass. See also:smelter
ASTM
A circular plate conveyor to effect a preliminary grading of coals and
removal of stone by hand. A screened-out fraction of the run-of-mine coal
is delivered to the table by chute from a conveyor. As the stream of coal
revolves on the table, the various grades of coal and the dirt are raked
into positions where they are diverted by plows into chutes. The operators
are positioned on the inner and outer edges of the table and the coal is
not handled but only raked. Syn:circular grading table
a. The geared rotating table that propels the kelly and the drill stem
when drilling a borehole with an oilfield-type rotary rig. Also called
rotary; table; turntable. Long
b. The mechanism used in some forms of rotary drilling to rotate the
drilling column. BS, 9
A rotor of cylindrical outline with radial, spaced plates or vanes
rotating on a horizontal axis, for controlling the flow of bulk materials.
A tippler designed to overcome the tendency for coal or dirt to stick to
the bottom of the tubs or mine cars. When the tippler is in the inverted
position, the car rests upon a vibrating frame that gives it a high-speed
vertical jolting motion, which frees any material tending to stick inside
the car. Nelson
rotating casing screw conveyor
A screw conveyor in which the tubular casing rotates at a different speed
or in an opposite direction to the conveyor screw.
See also:screw conveyor
A fault on which rotational movement is exhibited; a partial syn. of hinge
fault. CF:hinge fault; scissor fault. Syn:rotary fault
Turbulent flow involving all parts of a moving liquid.
Apparent fault-block displacement in which the blocks have rotated
relative to one another, so that alignment of formerly parallel features
is disturbed. CF:translational movement
AGI
One of four types of slope failure. Failure by rotational shear produces a
movement of an almost undisturbed segment along a circular or spoon-shaped
surface and occurs in comprehensive, uniform material. This material would
not be affected by geological planes of weakness. Failure of this type can
occur from causes that either increase the shear stresses or decrease the
shear strength of the material. Woodruff
A slide of homogeneous earth or clay in which the slip surface of failure
closely follows the arc of a circle. Nelson