822

THE COLLIERY GUARDIAN.

April 28, 1916.

position is shown in dotted lines in connection with com-
pressor 2. As the load on a machine of this type, that is,
the number of cubic feet of air passing through it, varies,
the pressure produced by it varies. For no load, the pressure
is a certain amount. As the load increases, the pressure
increases somewhat up to a certain point, and then decreases
again. At full load the pressure may be about the same as at
no load, and at over load the pressure will still further
decrease. In operation, the machines are all started and
brought up to speed with the valves closed, those of com-
pressors 2 and 3 being pinned closed by the pins 15. The
valve 7 of compressor 1 is then gradually opened by hand.
If the load on the entire system is less than a certain
minimum, pulsations will occur if the valve 7 is opened wide,
so it must be set at some intermediate point so as to eliminate
pulsations. Under these conditions, there is no need for other
machines, and they can be shut down. If, however, the
valve 7 can be opened wide without pulsations occurring, it
shows that the load is more than the minimum for one
machine. The valve 7 is then locked in the wide open posi-
tion, and the stop pins 15 of compressors 2 and 3 are
unscrewed, so that the check valves are free to open. If
the load on the entire system is less than the maximum load
for one machine, the check valves will remain closed, and
compressor 1 will carry the load. If the load on compressor

I	increases, when it reaches about full load the pressure in
the discharge pipe will be about the no load pressure of
machines 2 and 3. If it still continues to increase, the pres-
sure in the discharge pipe will become less than the no load
pressure of the other machines. When this occurs the valve

II	of one of these machines will open. The weights 14 of
these two machines will be so adjusted with regard to the
characteristics of the machines that the valve 11 of one will
open before the other. As soon as the valve 11 of the second
machine opens, say, compressor 2, the load will then be
divided between compressors 1 and 2/ Each of these machines
is now carrying less than full load, so that the discharge
pressure increases, and hence the valve 11 of machine 3 will
remain closed. When the pressure in the discharge pipe
again drops to’ the no load pressure, or slightly below, the
valve 11 of machine 3 will automatically open, and the load
will then be divided among the three machines. If, now, with
all three machines running, decrease in the load occurs as
soon as the load on each machine reaches a value where with
further decrease a decrease in pressure occurs, an unstable
condition will be set up, which causes oscillations of the
valves 11, which are nearly balanced. As soon as one of the
check valves reaches a nearly closed position (compressor 3),
the pressure becomes substantially the no load pressure, while
the pressure of compressor 1 still maintains a value greater
than the maximum load pressure, and hence greater than the
no load pressure. This will then cause the valve 11 to be
closed. The load will then be automatically distributed
between two of the machines. Should still further decreases
in load occur, the same conditions will arise, and the other
automatic gate valve will close. (Five claims.)

15585 (1915). Improvements
Johnson, of 47, Lincoln’s Inn

in Gas Producers. J. Y.
Fields, London (communi-

cated from abroad by W. Wood, of 4th and Chestnut-streets,
Philadelphia, Pennsylvania, U.S.A.).—Relates to gas pro-
ducers of the kind in which the body of the producer is
rot at able, and the stirring, or slicer, bars are suspended from
a fixed frame and extend into the interior of the said body,
and means are provided for rotating the stirring, or slicer,
bars (which are sometimes curved at the lower ends) to

agitate the material while being carried by the rotating
casing. The drawing is a vertical section. 1 represents the
base on which the gas producer is mounted; and 2 represents
the rotatable body portion of the producer. The air pipe
3 extends into the cone 4, and the producer is sealed in the
ordinary manner; 5 represents a worm wheel on the body
portion with which a worm 6, on a driving shaft 7, engages
to rotate the body portion of the producer. The body
portion rests upon flanged wheels 8, mounted in bearings.
At each side of the producer are beams 9, 9, and supported
on these beams, independently of the producer, is a beam 10,
which carries the stirring bars 11. 12 is the top section of
the producer, the said section being stepped, the portion 13
being less in height than the portion 14. In the portion
14 is a fuel opening and gas outlet. The joint between the
rotating body 2, and the top section 12 is sealed, in the
example illustrated, by a water seal 15. Each slicer bar

has a lower part 16,
which is curved, and
one of the bars has a
greater curvature than
the other, and conse-
quently has a more
extended sweep. Each
slicer bar is rotated as
the body portion
rotates, therefore, the
entire mass of the
charge is agitated and
kept in motion. Each
bar passes through an
opening 17, in the
beam 10, and has a
worm-wheel 18,
secured thereto, so
that the bar must turn
with the worm-wheel.
19 is a driven shaft
having secured to it
worms 2 0, which
engage with the
worm-wheels 18, so

that, as the shaft 19 rotates, rotary motion is imparted to
each of the slicer bars. A stationary bar may be mounted
in the bearings 28, in the beam-10, and one of the other bars
may be stationary and only one rotate. The shape of the
lower end of the stirring bar may be varied according to
circumstances. In the example illustrated, each stirring
bar has a longitudinal spline 21, adapted to receive a key
secured to the worm wheel, so that the stirring bar can be
vertically adjusted to any point desired, but will always
turn with the worm-wheel. In order to hold the stirring bar
in the position to which it is adjusted, transverse grooves
22, can be made in the stirring bar at suitable distances
apart, and a two-part collar 23, having a rib on its inner
surface, be clamped to the stirring bar, the rib entering
that one of the grooves 22 which is opposite it when the
bar is adjusted. The said collar is held between the upper
end of the worm-wheel 18 and a bearing 24, supported by
standards 25, on the beam 10. The weight of each stirring-
bar is taken by a bearing 26, on which rests the extended
hub of the worm-wheel 18. Each stirring bar passes
through a suitably packed stuffing box 27, in the top section

of the producer, as clearly shown in the drawing. The
stirring bars can be water cooled, which can be done in
the usual manner. As the body of the producer rotates,
one, or more than one, of the stirring bars will also rotate
around its own axis and cut a path in the charge. Such
paths may be arranged close together, or farther apart,
according to the speed of rotation of the stirring bar and,
where two bars rotate, it will be evident that one bar may
be arranged to cut through the path of the other bar, thus
completely stirring the charge. One, or all, of the bars may
be adjusted vertically so as to bring them in line, or out of
line, as desired. (Four claims).

24001 (1914). Improvements in and relating to Chain
Grate and the like Automatic Stokers. A. W. Bennis, of
Little Hulton, Bolton, Lancashire.—Relates to chain grate
and the like .automatic stoking apparatus of the type -applic-
able particularly to internally flued boilers, such as the types
usually used in marine work. Fig. 1 is a sectional side
elevation; fig. 2, a cross sectional view of the stoker; .and
fig. 3, a similar view from the back of the grate. The
lower member 1 carrying the chain grate is preferably in
the form of a semi-cylinder, and has flanges for carrying
the fire arch or for the reception of the shafts or bearings of
the guide rollers 3 of the chain grate 4. It may also be
provided with suitable bearings for the driving shaft or
drum 5 of the chain grate. The member 1 is inserted into
the base of the fire tube 6, preferably sb that a portion of
the cylindrical member 7 will project from the front 8 of
the boiler flue as shown (fig. 1). A stoker front 14, covering

Fig. 1.

Ji

the upper portion of the internal flue is preferably secured
to the outside of the flue 6, for instance by a clamping ring
12 arranged behind the heads of the rivets 11. The stoker
front 14 can be connected by means of hook bolts 13 engag-
ing behind this clamping ring 12. These bolts 13 may also
be hinged and pass through slots in the stoker front 14.
The arch 18 can be arranged to have portions 17 extending
upwards of similar contour to the flue 6, and then the head
or roof of the arch 18 can be carried by these portions 17,
which roof is of a greater radius than the flue 6, whereby
a space 19 will be left between the top of the coking arch
18 and the internal surface of the flue 6. The coking arch
18 may be perforated, as shown at 20, if desired. On the
lower portion 1 two longitudinal angle members 2 can be
secured to form runways for the wheels or guides 120, on
which the chain grate runs. The chain grate itself may
be built up in the usual manner, having side frames 21 to
support the guide rollers and the front and back drums, the
front drum being preferably only fitted with sprockets to
engage the chain 4, while the back drum 22 is preferably
more in the form of a guide drum, and is formed without
sprockets, being preferably four-sided, so as to reduce the
depth of the chain at the back. At the front end of the
furnace the member 1 is provided with a flange or lugs 15
for carrying a platform 23 for the coking arch. The plat-
form 23 has a rib 24 adapted to be shrouded by <a troughed
side bar 25 carried by flanges 90 on the sides 21, this bar

25	touching or nearly touching the sides of the outer links

26	of the chain grate 4, the space between this rib 24 and
the trough 25 being filled with small ash or sand so as to
prevent entry of an excess of air. The holes 20 in the
arch 18 allow a portion of the gases to pass through the arch
into the space 19. At the end of the arch farthest away
from the stoker front 14 a side bar 27 is provided, arranged
over and supported by a flange 28 on the lower cylindrical
portion 1. This side bar 27 is extended at 29 to form a
trough as shown,
and another side
bar 30 may rest in
this trough 29 to
touch or nearly
touch on its inner
side the side links
26 of the chain
grate 4, the space
between these two
side bars being
filled with small
ash, sand or the
like to protect
them from the fire
as much as pos-
sible. The side
bar 30 can be sup-
ported at its ends
by flanges on the
sides 21. Under-
neath the grate
adjacent to the
last supporting
roller 32 a bar of
metal or suitable
material 33 is pro-
vided carried by
the plates 21, and
slotted to receive
two side protecting
plates 34. In the
front of the last

18

roller 32 a damper
door 35 can be placed.
36 or the like passing
the front of the boiler,
clinkers from the back.

This can be' drawn up by a chain
over a guide 37, and extending to
when it is desired to clean out the

The usual guide rollers 3 for the

chain are mounted in the side plates 21. Between the
rollers 3 damping plates 39 are mounted, so that they may
be swung by mechanism (not shown) to allow a free passage
of air through the grate, or any number may be closed at
different places along the grate to regulate combustion upon
a known principle. The stoker may have a lifting fire door
40 and a cut-off 41 in the hopper 42 of usual construction.
The driving drum 5 of the chain grate has a worm wheel
43 keyed to it driven from a worm 44 operated from a
vertical shaft 45, having a bevel wheel 46 at its lower end
gearing with a bevel wheel 47 driven from a horizontal
main driving shaft 48. The shaft 48 may. extend right
across the front of the boiler. A change-speed gear box
providing a variable ratio of drive can be interposed
between the driving shaft 48 and the bevel wheel 47. The
semi-cylinder has an extension 7 beyond the end of the flue,
and protecting plates 49 may depend from this projection
to protect the change-speed gear from clinkers and ashes.
The front end of the extension 7 may be covered in by
plating 50 having hinged doors 51 at suitable places. Along
one or both sides of the stoker front an air trunk is led
from which pass pipes so that air may circulate to various
parts as required for cooling the parts of the stoker or for
applying forced draught to the stoker. The air trunk opens
into the space below the upper traverse of the chain grate
4 by'means of a mouth 56 (fig. 2). Compressed air prefer-
ably pre-heated, will therefore pass down the air trunk
through the mouth 56, and thence through the grate 4, to
accelerate combustion. Certain parts of the chain grate, for
instance (fig. 3), the platform 23, or bars 25, 27, or 30, are
cast hollow or cast about pipes to allow compressed air to
pass along them for cooling purposes. If desired, this air
may be directed beneath the upper traverse of the chain
grate, to be of assistance in combustion. The back drum
22 may also be hollow as shown at 57, for the purpose of air
cooling, and be connected to pipe 58 leading to the air trunk.
The fire door 40 may be cooled by passages 59 and a flexible
hose connection 60 may be made with the main wind trunk.
(Fifteen claims.)

PUBLICATIONS RECEIVED.

Transactions of the Institution of Engineers and Ship
Builders in Scotland ” (Vol. 59, Part 6), April; “ Bulletin
of the American Institute of Mining Engineers ” (No.
112), April; “The Engineering Magazine,” April, price
Is. ; “ The B.E.A.M.A. Journal ” (Vol. 2, No. 2), April,
price Is. net.

GOVERNMENT PUBLICATIOHS.

*** Any of the following publications may be obtained
on application at this office at the price named post free.

List of Articles declared to be Contraband of War, Id.

Customs : Form No. 115, lOd. per quire.

Statutory Rules and Orders, 1916 : No. 237, Customs
Order in Council, IJd.

A conference on engineering and scientific research will be
held on May 1 by the Society of Engineers in the Caxton
Hall, Westminster, when a paper on this subject will be
read by Mr. J. Fleming. ,

Utilising Danish Turf.—In order to meet the threatened
fuel famine resulting from the British coal restrictions, the
Danish Government issued an order to all municipalities
to take care that every bit of turf and moss is utilised to the
fullest extent. If private owners do not make use of this
fuel, the municipal authorities are to take it over and pre-
pare it for consumption. The entire scheme is under the
general control of the well-known Danish Association for
Heat Production.

An All-Electric Colliery.—The members of the Association
of Colliery Managers in India recently paid a visit to the
Burelia Colliery, by the invitation of Messrs. Bird and Com-
pany’s manager, Mr. P. T. Marley. This is the only entirely
electrified colliery in India. The property to be worked has
an area of approximately 1,500 biggahs. The seams are two
in number. In addition to these, there is a small area of a
seam 30 ft. thick in one corner of the property. Four shafts
of 14 ft. diameter have been sunk, in groups of two, at about
700 ft. centres, and 4,400 ft. apart, along the strike. The
depth to the bottom of the seam is 290 ft., the top seam being
85 ft. above at the Dahooka end, and 115 ft. at Chichuria.
The colliery is worked electrically throughout, the power
station and boilers being situated at the Chichuria pits. The
generating engines are two in number, of 300 horse-power
each—two-cylinder compound non-condensing, by Messrs.
Beiliss and Morcom. They are direct-coupled to Siemens
alternators of 250 kw. capacity, generating current at 2,200
volts, and running at 375 revolutions per minute. The
winding engines are four in number, and all of the same size
and type, having drums 6 ft. diameter, and 3 ft. 6 in. wide.
They are driven by a 25 horse-power motor, running at 500
revolutions per minute. The capacity of the winders is 200
tons in eight hours, using single tub cages and 15 cwt. tubs.
There is one pump at each dip shaft, each having a capacity of
6,000 gals, per hour against a head of 320 ft. Four addi-
tional dip pumps on trolleys of the three-throw type have
been delivered. They <are driven by a 3 horse-power motor.
The ventilating plant has not yet arrived. There will be
two Turbon fans, one at Chichuria and one at Dahooka. The
proposed method of working is on a large panel system, the
panels being 700 ft. wide, 'and it was proposed to work
right up to the outcrop and then take out the pillars with
a longwall coal cutter. This refers to the top 8 ft. iseam.
The pit bottoms are to be laid out with points and crossings
made of 241b. rails, so arranged that by means of spring
points the empty tubs will automatically take the empty
line. The ropeway is on the single rope system by Messrs.
Ropeways Limited. It is divided into two sections, one of
which, 4,400 ft. in length, is between the Dahooka and
Chichuria Collieries, and has a capacity of 30 tons per hour;
and the other section is capable of transmitting 60 tons
per hour from the Chichuria pits to the screens. The two
sections are driven by one 60 horse-power motor, but the
actual power taken is only about 30 horse-power. The
buckets have a capacity of lOcwts., and are 105 in number.
A steel bunker of 400 tons capacity has been erected at
both the Chichuria and Dahooka pits. The coal from the
pits is tipped into these bunkers, and then loaded into the
ropeway buckets by means of chutes.