1040

THE COLLIERY GUARDIAN.

November 13, 1914.

ABSTRACTS OF PATENT SPECIFICATIONS
RECENTLY ACCEPTED.

29 (1914). Process for Purifying Coal Gas. R. Fabry,
'The White Building, Fitzalan-square, Sheffield.—The object
of the present invention is to remove from the crude coal gas
so much carbon dioxide and sulphuretted hydrogen that no
more and even less acid impurities (CO2, H2S, and HON)
will afterwards remain in the coal gas than will be sufficient
to neutralise the ammonia then contained in the gas. These
remaining acid impurities will thus be removed with the
ammonia when the gas is further washed successively with
weak ammoniacal liquor and fresh water. For this purpose the
crude coal gas, after being cooled down to as near as possible
atmospheric temperature, and practically deprived of all its
tarry constituents, is washed in any suitable apparatus with
a combined solution of alkali carbonate, preferably potassium
carbonate, and caustic ammonia of suitable concentration,
and sufficient in quantity to absorb all the free carbon dioxide
and all the free sulphuretted hydrogen present in the coal
gas with simultaneous formation of alkali bicarbonate and
ammonium sulphide and hydro-sulphide, all of which are
retained in the washing solution. The gas is then passed in
the ordinary way through other or secondary washers in
suitable numbers, fed successively with weak ammoniacal
liquors and fresh water, and issues from the last of them
practically free from all the impurities it previously con-
tained, namely, ammonia, carbon dioxide, sulphuretted
hydrogen, and hydrocyanic acid. The ammoniacal liquor
obtained by cooling the crude coal gas, and by washing it
in the secondary washers, is collected, settled, and distilled
in the ordinary way preferably with addition of milk of
lime, the ammonia expelled from the stills being converted
either into ammonium sulphate or concentrated ammonical
liquor. The spent combined solution flowing from the
primary washer is now first allowed to separate by settling
from the naphthalene which it has collected, and is then sub-
jected to partial distillation in a dissociating still of suitable
construction, preferably of the system forming the object of
separate specification, No. 337/1914, in which dissociating
still carbon dioxide and sulphuretted hydrogen are set free
owing to the dissociation of the alkali bicarbonate and
ammonium sulphides caused by the gradual heating of the
said combined solution. The original compounds of the
combined solution, namely the alkali carbonate and the
caustic ammonia, are thereby regenerated, and after the
distilled solution has been thoroughly cooled down to the
temperature of the coal gas entering the primary washer,
or even to a lower temperature, it is again pumped in the
primary washer, and goes through the same cycle of chemical
and physical changes over and over again. The noxious
gases issuing from the dissociating still consist largely of
carbon dioxide and sulphuretted hydrogen, but they also
contain a small percentage of ammonia, which it pays to
recover. To this effect the said noxious gases are preferably
passed through an acid lye of ammonium sulphate, which
will absorb whatever ammonia is carried by them; or when,
as is generally the case, a sulphate of ammonia plant is
established at or near the gas works or by-product coking-
plant, the gasses from the dissociating still and the ammo-
niacal vapours from the ordinary ammonia still or stills are
mixed and passed all together through a common saturator
for the purpose of converting the whole of the ammonia
from both sources into marketable ammonium sulphate, and
of uniting the sulphuretted hydrogen contained in both the
noxious gases and the ammoniacal vapours, for subsequent
treatment by partial or total combustion. The noxious gases
from the dissociating still, whether or not mixed with
ammoniacal vapours, are, after being deprived of their
ammonia, either partially burnt in a Claus kiln for the pur-
pose of recovering their sulphur in a marketable form, or
completely burnt with excess of air whereby their sulphur
may then be converted into sulphuric acid by any of the
well-known processes. The process of purifying coal gas
described above can also be used in plants where the coal
gas is thoroughly cooled down before passing it through an
acid lye of ammonium sulphate for the purpose of recovering
its ammonia. In this case, however, only the bulk of the
impurities (C02 and H2S) can be extracted from the gas by
means of this process, owing to the fact that the ammonium
compounds left in the gas, and which are decomposed by
the acid lye of ammonium sulphate, produce free carbon
dioxide and free sulphuretted hydrogen, which remain mixed
with the coal gas, and can only be extracted from it by
means of ordinary dry purifiers. Even then the present
invention will be applied advantageously whenever the yield
and quantity of recoverable sulphuretted hydrogen are suffi-
cient to justify of its being converted into marketable sulphur
or sulphuric acid'. The process of purifying coal gas
described above could also be carried out by washing the
gas firstly with a solution of an alkali carbonate, and
secondly with a solution of caustic ammonia, both solutions
being used and regenerated separately. (Three claims.)

3526 (1914). Improvements in Centrifugal Fans. P. W.
Allday, a director of Alldays and Onions Pneumatic Engi-
neering Company Limited, of Great Western Works,
Sydenham-road, Birmingham, Warwickshire, and T. H.
Plummer, Great Western Works, aforesaid.—Has reference
to centrifugal fans of the multi-wheel type having axial
intake openings at opposite ends, and a tangential discharge
at the middle, the casings of the end wheels or runners
having curved vanes or webs on one side of the interior to
guide the air compressed by the rotation of the end wheels or
runners to the axial inlet openings of the inner or middle
fan, and the said invention consists of the construction and
arrangement or combination of parts whereby an increased
volumetric efficiency is obtained and a silent or nearly silent
action results. In constructing the improved multi-wheel
fan three fans are employed, the two end fans, when the'
fan is at work, compressing or forcing air into the inlet
openings of the casing of the middle fan as is usual, and
the make of the casing of the middle fan and base of the
compound fan, which is in one, therewith being in two
symmetrical halves, the flanges of which meet in a vertical
plane, and are bolted together, or the casing can be made in
four parts, the other division passing through and contain-
ing the axis of the runner shaft. The runner of the middle
fan may consist of a double inlet single wheel as heretofore
or two single inlet runners secured base to base. The
runner or runners of the middle fan casing receive axially
the air compressed to a certain pressure by the end fans,
and discharge the same into an annular space, having a
tangential discharge opening preferably in the base. The
casings of the two outer or end fans may be made in two
symmetrical halves meeting together in a horizontal plane
or plane containing the axis of the fan, but are preferably

made in four parts, and the said casings are secured by screw
pins to the casings of the middle fan. The inner walls or
parts of the end casings, that is, the walls adjacent to the
middle casing, have curved webs or vanes, which guide the
air forced or compressed into the circumferential space of
the casings into the axial eyes or openings, constituting the
inlet openings of the middle fan. The bearings for the
runner shaft are fixed to or carried by the lower halves of
the outer casings, and the common hub of the three runners
is preferably made in two halves meeting together end to
end at the middle of the inner fan. . By this arrangement a
convenient means of balancing the runner is obtained, as
the one half can be partially rotated with respect to the
other half when the balance of the runners is being tested





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until the best balance is ascertained, when the three runners
are secured together by the bolting of the two halves end
to end. Each of the runners is provided with concentric
flanges, which work between annular concentric flanges on
the casings, and constitute obstructions or baffles to prevent
the escape or return of the compressed air to the inlet open-
ings. Fig. 1 represents in longitudinal section a two-stage
compression centrifugal fan constructed according to the
said invention; fig. 2 is an end elevation of the same; and
fig. 3 is a half plan and half section of one of the end fans,
the said section being taken on the dotted line 3—3, fig. 2.
Fig. 4 is an elevation of the inner half 'of one of the end
casings of the fan showing the webs or vanes which guide
the air compressed by the end fans to the axial openings in
the middle casing. (Five claims.)

3893 (1914). Improvements in and Relating to the Regu-
lation of Turbines. Akt-Ges. Brown, Boveri et Cie., of
Baden, Switzerland.—Relates to the regulation of turbines,
and more particularly steam or gas turbines, in which both
the main inlet valve and the additional valve oi valves are
oil controlled. The invention consists in first moving the
means controlling the additional valve comparatively slowly,
and without raising the valve itself, then for a short time
moving the valve very rapidly, subsequently completing the

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movement at a reduced rate, the additional valve being so
constructed and connected to its operating means that it
completes the stroke independently of the operating means.
Fig. 1 illustrates a scheme of a controlling system with
governor, a main valve, and one additional valve; figs. 2—5
are longitudinal sections through an additional valve and
its operating means (which may be a servo-motor), illustrating
different positions assumed by the various parts during regu-
lation. (Four claims.)

22435 (1913). Improvements in Band Brakes, particularly
applicable to Electrically Operated Band Brakes for Electric
Cranes and the like. The Lancashire Dynamo and Motor
Company Limited, of Trafford Park, Manchester; R. S.
McLeod, of 21, Victoria-avenue, Didsbury, near Manchester;
and H. B. Whitmore, of Brereton Cottage, Bramhall-lane,
near Stockport.—Relates to band brakes of the kind adapted
to act equally well for either direction of rotation of the
drum, in which the opposite ends of the band are connected
to band actuating members, the movement of which is
limited by fixed stops so arranged that when the brake is
applied one or other of the two actuated members abuts
against its stop, according to the direction of rotation of the
brake drum, and the invention is particularly applicable to
that type of this class of geay in which the brake is applied
by a spring or other mechanical means, and released by a
two-part solenoid core. Fig. 1 is a diagrammatic view of
an explanatory character; figs. 2 to 4 are views showing the
invention applied to an electrically controlled brake for a
lift or crane, fig. 2 being an elevation, fig. 3 a plan, and
fig. 4 a side elevation ; figs. 5 and 6 are views similar to

the lower part of fig. 2, and illustrate modifications. Accord-
ing to the invention, the brake band is crossed and the ends
are coupled respectively to two bars articulated by short
links to a fixed base, and capable of limited movement in a
direction approximately parallel to a tangent to the brake
drum; these two movable bars are respectively coupled
to two cores of a solenoid, each of which cores is capable



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of movement relatively to the solenoid, a spring or weight
being provided which tends normally to produce relative
movement between the bars in such a direction as to apply
the brake, the solenoid, when energised, overcoming the
said spring- or weight, and releasing the brake. (Three
claims.)

23393 (1913). Improvements in Safety Devices or
Arresters for Colliery Winding Cages, Hoists, and the like.
J. Yates, of 13, Joseph-street, Sutton, St. Helens, Lanca-
shire, and C. Heyes, of the Locomotive Inn, Sutton, afore-
said. — Relates to safety devices or arresters for colliery
winding cages, hoists, and the like, and comprises improve-
ments in or modifications of former invention, No. 5858 of
March 10, 1913. The present invention includes several
modifications or means of actuating the grippers by connect-
ing each pair of grippers together with toothed gearing so
that the movement of one gripper lever is positively com-

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municated to the other, .also improved means for actuating
each pair of grippers when three or more pairs of grippers
are used. In the arrangement shown in elevation in fig. 1
and in plan in fig. 2, the safety devices or arresters are
applied to a cage having three conducting rods. Figs. 3
and 4 show in elevation and plan respectively a modification
in figs. 1 and 2 for applying the invention to a colliery
winding cage with three conducting ropes, and in which the
gripping blocks c c are positively actuated by toothed gear-
ing. (Seven claims.)

23699 (1913). Improvements in Tip Wagons. G. A.
Wood, of 172, W. Fifth-street, and formerly of 100,
E. Twelfth-street, St. Paul, Minnesota, U.S.A.—Relates to
an improved hydraulic unloading device for vehicles, and
has for its object to provide an efficient apparatus for tilting
the body of a vehicle for the purpose of quickly dumping the
contents thereof. The invention therefore consists in pro-
viding an apparatus wherein means are provided for cir-
culating fluid in a system of piping having therein controlling
means for the fluid, whereby the elevating means for the
tip body is adapted to stop automatically in an elevated
position by the continuous circulation of the fluid. Fig. 1
is a side elevation of an automobile truck showing the
invention applied thereto; fig. 2 is a diagrammatic view of
the improved apparatus; and figs. 3, 4, 5, 6, and 7 are views
of details, part of which are illustrated in section. In oper-
ation when it is desired to dump the contents of the body C,
the operator throws the clutch 18 by means of the levers 19
and 20 into connection with gear 15, which operates the
gear pump 13 by the engine B, and the valve 24 is turned
into the position illustrated in fig. 6, directing the flow of
liquid to the piston through the pipe 26, causing it to rise
in the cylinder E, and at the same time elevating the for-
ward end of the body C by means of the yoke 71 and con-
nectihg arm 6. When the piston reaches a point just above
the port 31 it will stop automatically, and the liquid will
flow out through the port 31, pipe 32, and valve 24, to the
gear pump 13. and continue through loop 23 and pipe 26 to