A passage for the escape of gases from a mold while the molten metal is
being poured. Standard, 2
Said of minerals naturally dried to equilibrium with the prevailing
atmosphere. Pryor, 3
An analysis expressed on the basis of a coal sample with moisture content
in approximate equilibrium with the surrounding atmosphere. BS, 4
a. An opening driven for ventilation purposes, often inclined and driven
in stone.
b. A drift connecting a ventilation shaft with the fan.
a. A small diamond drill driven by either a rotary or a
reciprocating-piston air-powered motor; used principally in underground
workings. Long
b. As used by miners, a percussive or rotary-type rock drill driven by
compressed air. CF:air rig
a. Dry to such a degree that no further moisture is given up on exposure
to air. Most air-dry substances contain moisture that can be expelled by
heating them or placing them in a vacuum. Webster 3rd; Fay
b. Said of timber the moisture content of which is in approximate
equilibrium with local atmospheric conditions. CTD
a. Tubing that conducts air, usually from an auxiliary fan, to or from a
point as required in the mine. BS, 8
b. An air box, canvas pipe, or other air carrier for ventilation.
Hess
Method of dividing a substance into various particle sizes by means of air
currents. Bennett
An appliance for producing, by means of currents of air, a series of sized
products from a finely crushed mineral (e.g., for the paint or abrasive
industries). See also:air classification; air classifier. CTD
A narrow roadway driven in a coal seam parallel and close to a winning
headway chiefly for ventilation; it usually acts as a return and is
connected at intervals of 10 yd (9 m) or so to the headway by crosscuts.
Shaking table in which ore is worked dry, air being blown upward through a
porous deck so as to dilate the material. Pryor, 1
See:air current
A flow-equalizing device that is fitted to tube breathing apparatus. There
are two kinds in general use, one consisting of a flexible, corrugated
rubber tube and the other a canvas fabric bag. On inspiration, air is
drawn partly from the equalizer, which is reduced in volume, and partly
from the tube. On expiration, the equalizer restores itself to its
original volume and in doing so draws air through the tube. Thus the air
is kept flowing very nearly in a continuous stream, and the wearer,
without the aid of bellows or rotary blower, experiences very little
resistance to breathing. Mason
An instrument that measures and provides readout of the flow of air in a
pipe or hose in cubic meters per second.
See:air circulation
The circulation of air through the drilling apparatus during drilling to
cool the bit and to remove the cuttings from the hole. BS, 8
A fan with an airfoil-shaped blade that moves the air in the general
direction of the axis about which it rotates. Strock, 2
Malleable-iron furnace.
Å €¿ ÚÀ k DICTIONARY TERMS:air gate a. Mid. An underground roadway used princi
[\B]air gate[\N]
A tool in which a hammerhead is activated by means of compressed air. The
airhammer is called a jackhammer in coal mining and jackleg-hammer in
hardrock mining. The tool is used to drill blastholes to grade or take up
bottom or to advance a stope. Crispin
An appliance to warm the air as it enters the downcast shaft or intake
drift. In countries where the winter is very cold, nearly all mines are
equipped with air heaters of the oil-fired, gas-fired, or electric type.
a. Hoisting machinery operated by compressed air. Fay
b. A small portable hoisting machine usually mounted on a column and
powered by a compressed air motor. Also called tugger. Long