Used in open-hearth furnaces to increase the furnace temperature by
preheating the fuel gas and air previous to their combustion in the
furnace. Newton, 1
Brick used in furnace regenerators to recover heat from hot outgoing
gases, and later to release this heat to cold air or gas entering the
furnace; so called because of the checkerboard pattern in which the bricks
are arranged. Harbison-Walker
In hydraulics, the condition of a river with respect to the rate of its
flow as measured by the volume of water passing different cross sections
in a given time. Webster 3rd
a. Extending over large areas in contradistinction to local or restricted
areas. Fay
b. In gravity prospecting, contributions to the observed anomalies due to
density irregularities at much greater depths than those of the possible
structures, the location of which was the purpose of the survey. The term
is also employed in an analogous sense in magnetic prospecting.
AGI
a. The more localized departures in the Earth's field from the values that
would be predicted if the field were to originate with a single magnet
oriented along the magnetic axis. These have maximums as great as 10,000
gamma, which is about a third the total intensity at the equator, and
extend over areas as large as a million square miles. The locations of
such features do not change with time as do anomalies associated with
secular variation. Dobrin
b. The departure of a measured quantity from an expected or theoretical
value on a scale larger than the most rapid spatial variations of the
measured quantity; typically variations over tens to hundreds of
kilometers.
The nearly uniform inclination of strata over a wide area, generally at a
low angle, as in the Atlantic and Gulf coastal plains and parts of the
Midcontinent region. CF:homocline
A general term for metamorphism affecting an extensive region, as opposed
to local or contact metamorphism. CF:dynamothermal metamorphism;
local metamorphism.
A surface of discontinuity in sedimentary rocks that extends throughout an
extensive region. It may record a significant interruption in deposition,
tectonics, or erosion of older strata.
Premises registered with the local authority for the storage of not more
than 60 lb (27.2 kg) of explosive. See also:licensed store; magazine.
BS, 12
A 12-in (0.3-m) scale divided into tenths and hundredths of a foot, used
for accurate measurement in conjunction with a steel band that is
graduated only in feet. See also:band chain
The layer or mantle of loose incoherent rock material, of whatever origin,
that nearly everywhere underlies the surface of the land and rests on
bedrock. It comprises rock waste of all sorts: volcanic ash, glacial
drift, alluvium, windblown deposits, organic accumulations, and soils.
Syn:mantle rock
Wire rope or cable in which the individual wire or fibers forming a strand
are twisted in a direction opposite to the twist of the strands. Also
called ordinary lay. Syn:standard lay
See:left regular lay
A polygon having equal sides, and the angles between these sides are
equal. Jones, 2
The sampling of the same coal or coke received regularly at a given point.
There are two forms of regular sampling, namely, continuous sampling and
intermittent sampling. BS, 2
All places in a mine through which there is a positive flow of air without
the aid of a blower fan or of ventilation tubing.
In contrast with choke feed, feed that is throttled back to a value below
the full capacity of the crusher. South Australia
In mine ventilation, a split where it is necessary to control the volumes
in certain low-resistance splits to cause air to flow into the splits of
high resistance.
A gate used to vary size of opening so as to control the flow of material
through the opening. See also:bin gate
a. A ventilating device, such as an opening in a wall or door; usually
placed at the return of a split of air to govern the amount of air
entering that portion of a mine. Kentucky
b. A device for creating shock loss to restrict passage of air through an
airway. Regulators are usually set in doors as adjustable, sliding
partitions that can be varied to the desired opening. In their simplest
form, for temporary service in an untraveled part of a mine, regulators
consist of doors propped partially open. Where possible, regulators are
located on the exhaust side of a split (in a return airway) to minimize
interference with traffic. See also:ventilation
Syn:ventilation regulator