Makch 27, 1914.

THE COLLIERY GUARDIAN

701

water currents or fluids in coal or ore washing plants, and
for testing the coal or ore with regard to its contents of
undesirable ingredients or the proportion of different sizes
or grades in a given quantity, so that the results can be
represented by curves and diagrams. At the same time it
enables the attendant by use of the results obtained thereby
to ascertain at any time if a coal washer is working in the
best possible and most economical manner to ensure a first-
class product free from slate to be obtained, and to avoid
any loss in coal that might otherwise be washed away with
the slate or dirt. An apparatus according to the invention
is designed for the following functions:—(1) To ascertain
if the coal is free from slate; (2) to ascertain if the slate
contains no more coal; (3) to ascertain a suitable current
for a given grade of coal; (4) to ascertain the proportion of
slate or different ingredients in a given quantity of raw
material and the proportion of grades of marketable
products in the same. The apparatus comprises in com-
bination a supply tank having a valved outlet provided
with an indicator, a rigid U tube provided on one limb with
a transparent extension or cube to receive the coal or the like
sample to be tested, and a graduated reservoir carrying
means for separating the coal from the water which is
adapted to be passed through the tube from the supply
tank and into said reservoir. Fig. 1 is a diagrammatic
sectional elevation of the apparatus; fig. 2 is a side view of
the reservoir and tubes ; fig. 3 is a detail sectional elevation
of the tapered head on the transparent test tube. The
apparatus is calibrated by opening the valve J, whereupon
the water flows down through A, and rises with a certain
force through B and F, and flows over through G1 into G,
and thence into H by way of the outlet G2. The stream
ascending in F is accelerated in the piece G1 on account of
its tapered form. The following formula is then obtained.

V = —
st

where V = velocity of water in F.; Q — quantity of water
flowing through tube F in t seconds; s = area of tube F;
t = number of seconds. The various velocities obtained by
calculation are marked on the disc T for future use. In
using the apparatus, the sample of coal to be tested with
regard to its contents of slate or dirt and the proportions
of different market sizes, is placed, after weighing, in the
tube F, where it rests on a copper sieve between B and F.
The stream is then turned on at the lowest velocity marked
on the disc on the valve J, whereupon the smallest particles
are first separated in the tube F. These flow with the
current through the nozzle G1 into one of the tubes K
mounted on the top of the reservoir H, the tubes having

K Fig-,2.

Fig-.l.

-D

H

-E

-B

Fig- 3.

wire bottoms, which allow the water to pass into the
reservoir H, but retain the coal. As soon as no more
parts flow through G1 the water in reservoir H is measured
by means of marks in litres or gallons on the same, thus
enabling the operator to see the required amount of water
at a known velocity to separate grains of coal of a certain
size, from a definite weight of coal under test. The tube K
in question is twithdrawn, and the collected coal removed
therefrom for examination. The current is turned on for
the second degree marked on J, and grains of larger size
are removed from F, and collected in the next tube K.
This process is repeated until all material is removed from
the tube F. The coal sample has thus been divided up or
graded into a number of samples of different sized particles.
These coal samples are dried and weighed. The difference
between the weight of the sample and the sum of the
weights of all the grades obtained in the tubes K represents
the weight of the dirt and the like carried away with the
waeh water. (Three claims.)

5467 (1913) Improvements in and relating to Detectors of
'Combustible Gases. A. Philip, B.Sc., and L. J. Steele,
M.I.E.E., electrical engineer, both of his Majesty's Dock-
yard, Portsmouth.—Relates to catalytic detectors in which
the indication is given by the deflection of a galvanometer.
For example, a catalytically active and an inactive wire
may be arranged in parallel each in series with one winding
of a differential galvanometer, or may form arms of a
Wheatstone bridge joined to a battery and galvanometer in
well-known manner. In order that the instrument may
readily be brought to zero reading, it is proposed to make
use of the junction pieces which unite the supports of
separate wires as a means of adj usting the resistance of the
various circuits—for example, for balancing the arms of a
Wheatstone bridge, in order to obtain an initial zero
reading. To this end such junction pieces are preferably
made of resistant material as—for example, German silver,
platinum, or better, platinum silver alloy which has but a
small temperature coefficient, and are made of sufficient
length to afford the necessary range of adjustment. The
leads running to the galvanometer or to the battery, in the
Wheatstone-bridge arrangement, preferably those to the
galvanometer, are no longer permanently secured to these
junction pieces but are joined to insulated metal arms
which are capable of sliding along the junction pieces. It
is not enough, however, to adjust the resistances of the
arms accurately. For supposing that the instrument has
an exact zero reading it may still be found that when
indicating the presence of combustible gas its reading does
not remain steady. It may gradually fall or it may

gradually rise. This phenomenon is found to be due to
slight differences in the facility with which the active and
inactive wires are enabled to radiate their heat. It is
preferable to have the wires enclosed in tubes. Supposing
that when all the wires are thus enclosed the reading
gradually falls. Then if the tube surrounding the inactive
wires is wholly removed the reading may, instead, rise.
Use is made of this discovery to provide for the balancing
of the radiation effects so that the reading remains substan-
tially constant long enough for careful observation; this is
done by {making openings—which may be adjustable—in
the tubes around the wires, preferably in the tube around
the inactive wires. While the instruments before devised
have been so designed as to be to a large extent self-
protecting, with the result that the active wires are not
liable to become fused through exposure to a rich mixture
of combustible gas, it is further desirable to avoid the
excessive heating of the wires that may occur if they are
exposed to mixtures which, though far from being rich, are
beyond the danger point commonly recognised in mining
work. The wires are commonly run at a very dull red heat
so that they are practically invisible. But the presence of
a percentage of combustible gas rather above the danger
point is sufficient to bring them to fairly bright incan-
descence. Hence if a window be provided in the tube about
the wires and in the outer casing, it is easy to make a
preliminary test by switching on current to the wires and
observing them through the window. If they begin to
glow there is no need to delay to take readings, for it is
certain that the atmosphere is beyond the danger point,
and the current may be immediately switched off. If they

I JO

-/z

7/3

2— 16

do not visibly glow a reading can be taken in the ordinary
manner to ascertain the precise percentage of gas present.
Fig. 1 is an elevation of a complete detector with its casing
in section. Fig. 2 is an elevation, the upper part partly
in section, of the tubes surrounding the wires. (Five
claims.)

12810 (1913); Improvements in or relating to Machines for
Crushing Stones, Ore and the like. T. G. Rennerfelt, of
29, Timmermansgatan, Stockholm, Sweden.—Relates to
machines in which the material is crushed between two
jaws, one of which is stationary and the other movable, the
movable jaw being actuated by a lever arm fulcrumed in
the frame of the machine. The machine comprises a frame,
a jaw arranged to swing in the frame, an unequal-armed
lever fulcrumed in the frame and means for oscillating the
lever, and is characterised by the fact that a roller is
mounted between the jaw and the shorter arm of the lever
and arranged to transmit pressure and to roll between the
lever and the jaw. The part of the lever which is in
contact with the roller is convex, and the angle between
the directions of the pressures which act upon the roller
from the lever and from the jaw does not exceed twice the
angle of friction. The accompanying drawing shows a
vertical cross-section of the crusher. (Four claims.)

a

11

No. 12810 (1913).	No. 13610 (1913).

13610 (1913). Improvements in and relating to the Cooling
of Apparatus Built in connection with an Electric Motor.
Aktiengesellschaft Brown, Boveri et Cie., of Baden,
Switzerland.—Consists in an installation in which the air
can circulate freely between the casings, no reducing means
being used. The accompanying diagrammatic drawing
shows one way of carrying the invention into effect. In the
form illustrated the apparatus a, such as a transformer,
which is to be cooled, is built on the motor casing g and
Surrounded by a casing k, which encloses it from the
outside. The motor casing g is at this point provided with
openings ox o2, through which passes a part of the codling
air delivered, for example, by the fan v in the direction of
the arrow, passing along and in contact with the apparatus a.
The path of the air is, if desired, determined or controlled
by means of baffle plates b. (Two claims.)

15273 (1913). Process and Apparatus for Intermittently
Producing Oxygen for Inhaling Purposes. G. Matschinski, of
No. 46, Alexander-strasse, Frankfurt a/M, Germany.—An
oxygen generator is used in conjunction with an inhaler,
the former device consisting of a receptacle containing a
solution of oxygen yielding salts, and the wide tapered neck
of the receptacle being closed by another tapered vessel in

which a reagent is placed and which terminates at its
bottom into a capillary tube. Near the top of the lower
receptacle a tubular extension is fitted to which the flexible
tube of an inhaler may be fitted. The drawing given by
way of example shows a vertical section of an apparatus
made, for instance, of glass. T (Two claims.)

No. 15273 (1913).

16910	(1913). Process of Burning Solid Fuel. A. G.
Glasgow, 38, Victoria-street, Westminster.— Consists in
preventing the formation of clinkers in the combustion of a
bed of fuel having a fusible ash by so applying the gas-
making fluids (usually an air blast) as to produce a rela-
tively high-temperature zone intermediate of a relatively
low-temperature zone and that end of the fuel bed to which
fuel is fed, some unconsumed carbon passing through the
hotter zone, and such carbon being burned in the cooler
zone. ^Usually the invention is carried out by maintaining
in the fuel bed superposed zones of relatively high and low
temperatures, such as will and will not melt and agglutinate
the residuum or ash into clinker by apportioning a divided
blast between them; feeding through the upper and hotter
zone a sufficient quantity of unburned fuel along with the
residuum or ash of the burned fuel for preventing agglutina-
tion of the partly-melted ash or residuum into clinker, and
feeding the last-mentioned unburned fuel and divided
residuum to the lower and cooler zone, and there burning
such fuel at a temperature insufficient to agglutinate the
divided residuum. Fig. 1 is a vertical section of one type
of gas-producer or generator; and fig. 2 is a similar view of
another type. (Three claims.)

16911	(1913). New or Improved Process of Burning Solid
Fuel.. A. G. Glasgow, of 38, Victoria-street, Westminster.—
Consists in maintaining in the fuel bed superposed zones of
relatively high and low temperatures, such as will and will
not melt and agglutinate the residuum or ash into clinker
by changing the direction and by apportioning the quantity
of flow of blast through them ; feeding through the hotter
zone a sufficient quantity of unburned fuel along with the

F^2

residuum or ash of the burned fuel for preventing aggluti-
nation of the partly melted ash, or residuum into clinker,
and feeding the last mentioned unburned fuel and divided
residuum to the cooler zone and there burning such fuel
at a temperature insufficient to agglutinate tne divided
residuum. Fig. 1 is a vertical section of one type of gas
producer or generator, and fig. 2 is a similar view of
another type. (One claim*)

19697 (1913). Improvements relating to the Production of
Oils from Coal, Cannels and Shales. A. Rollason, of Lime-
grove, Long Eaton, Derbyshire.—-The object is to utilise
coals, cannels and shales, which are high in oxygen, for the
production of endothermic hydrocarbons, which is carried
out by adding to the coals, cannel or shale, before charging
the retort, or whilst in the retort, during carbonisation, a
substance which will diminish the union of the hydrogen
and oxygen and allow the union of the atoms of carbon and
hydrogen forming the molecules of the various hydro-
carbons, thus preventing the combination of hydrogen and
oxygen to form water, and the deposition of amorphous
carbon. In carrying out this invention the coal is first
crushed, and a percentage (approximately between 3 and
5 per cent.) of finely ground limestone, or other suitable
carbonate, is added, proportionate to the oxygen contained
in the coal, &c., as, for example, 3 to 5 per cent, of limestone
to coal containing from 8 to 131 per cent, of oxygen. The
crushing of the coal and the fine grinding of the material
added is for the purpose of providing a large surface area
for the evolved gases to come into contact with the atoms
of the carbon dioxide now diffused in the charge being
carbonised, and to provide a free passage for the heat into
the interior of the charge, and a ready exit for the gases as
evolved, so that by their surface action the whole of the
gases come into intimate contact with the particles con-
taining the carbon dioxide. Upon carbonisation, the charge
is slowly heated up until a temperature of approximately
500 degs. Cent, is reached. The water contained in the
coal, &c., is driven off at a temperature between 85 and
105 degrees Cent., the carbon dioxide contained in the
charge is evolved at a comparatively low temperature, and
by its inert properties retards the evolution of the com-
bustible gases until a temperature between 130 and
175 degrees Cent, is reached; upon contact of these gases
with the carbon dioxide disseminated in the charge, the
action of the affinity of the oxygen for hydrogen is
diminished, and the volume of water which would be
otherwise formed is reduced. Upon the formation of the
endothermic hydrocarbons the temperature of the charge

{Continued on page 704.)