618

THE COLLIERY GUARDIAN

September 24, 1915.

average cost of generating power is 0*3d. per unit, includ-
ing depreciation of plant. About 240 tons of fuel are
gasified each month to do the work required.

Langwith Plant,—This is, no doubt, one of the finest
Mond by-product plants installed' at any colliery. There
are eight producers, five of which are now at work. Each
producer gasifies about 25 tons of fuel. A rough pit
slack of the following analysis is used :—Ash, 10 to 12
per cent.; volatile matter, 28 to 30; nitrogen, 1*3 to 1’4.
The producers work 24 hours per day through the whole
year, 10 cwt. being dropped in each charge about every
half-hour. The long pokers are used every two hours,
or oftener if necessary. The air and steam blast show a
water gauge of 24 in.

The temperature of the air blast is 85 degs. Cent., and
the temperature of the steam blast 210 degs. Cent. The
temperature of the gas coming off the producer is roughly
800 degs. Cent., which is cooled down to about 40 degs.
Cent. About 62 cu. ft. of gas is got from each pound of
fuel, the analysis of the gas being as follows :—

Per cent.

Carbon dioxide (CO2) .............. 16*2

Oxygen (O) ......................... 0’0

Carbon monoxide (CO)................ 8'0

Hydrogen (H) ....................   23*6

Methane (CH4) ...................... 3*4

Nitrogen (N)....................... 48’8

The gas is used for firing boilers, three of which are
used for the purposes of the plant. About 801b. of
sulphate of ammonia, and about 4 gals, of pitch are
being obtained from each ton of fuel gasified. An
average of 25 men are employed each shift of 12 hours.

Denaby Main Colliery Plant,—This gas producer plant
—which is in course of being installed to generate 70,000
cu. ft. of gas per hour when gasifying small coal—con-
sists of a producer with steam-driven blower, gas washer,
gas cooling tower, gas holder governor, two centrifugal
cleaning fans, tar baffle and dash box, and two scrubbers,
together with the necessary piping, connections, etc.

The producer is 10 ft. inside diameter, and comprises
a mild steel casing, provided with suitable brackets for
supporting the same over a water lute in the foundations,
through which the ashes and clinkers are withdrawn.
The producer is fitted with a charging hopper having a
suitable valve with balance weight for feeding in the
fuel, the top of the hopper being provided with a sliding
lid. Top and bottom poking holes, a special grate of
cast iron firebars, supported in the form of an inverted
cone, with the necessary firebar rings and air inlet con-
nection, designed so as to distribute properly the blast
around the fire grate, are included. The producer casing
is provided with a firebrick lining of best quality fire-
bricks, special fireclay blocks forming the crown of the
producer. A steel chequer plate operating platform is
provided at the level of the top of the producer, with the
necessary hand railing and ladder to give access to the
platform from the ground level.

The gas outlet of the producer is connected up through
a plate valve and dust outlet to a Mond gas washer 5| ft.
wide, 14 ft. long, and 9 ft. high, in which vessel a revolv-
ing dasher, driven by belting from an electric motor,
creates a water spray, which effectively washes the gas as
it passes on through its way to the gas cooling tower. This
tower is a vertical cylindrical vessel 32| ft. high, and
5| ft. in diameter, and is filled with ring tiles, on which
water is sprayed from the top, the gas entering at the
bottom of the tower, and leaving at the top. From the
tower the gas passes into a gas holder governor 8| ft. in
diameter, which is arranged to operate an air relief valve
fitted on the air blast main, thus regulating the make of
gas in accordance with the requirements of the load.
From the holder the gas passes on to the centrifugal
cleaning fans, which are run in series. Each fan is
driven separately by belting from an electric motor, and
is supplied with water and drain connections. From the
second fan gas passes through a tar baffle and pressure
regulating box into a gas collecting main, from which
connections are taken to two scrubbers, which are built
up of cast iron plates, and provided with suitable trays
for carrying the packing material. The scrubbers are
also provided with suitable overhead gear for lifting the
covers, so as to give easy access for cleaning and re-pack-
ing the scrubbers. The outlets of the scrubbers are
connected up to the gas main leading to the engine.

The air blast for the producer is provided by a steam-
driven blower of the Roots type, the exhaust steam from
the blower engine being passed into the blast pipe, where
it mixes with the air blast in the producer. At a suitable
height over the producer is mounted a circular coal
bunker, 7> ft. in diameter, with a capacity of about five
tons, fitted with hand-operated discharge valve imme-
diately over the producer hopper. This bunker is fed
by a bucket type electrically-driven elevator, which lifts
the coal up from the elevator boot. This boot is so
arranged that railway wagons can run over it and dis-
charge into it their contents.

(To be continued.)

Immingham Coal Exports.—There was no export of coal
from Immingham during the week ending September 17.
During the corresponding period of last year, the totals were
28,436 tons foreign and 1,750 tons coastwise.

South Wales Institute of Engineers.—An ordinary general
meeting will be held at the Metal Exchange, Swansea, on
Tuesday next, at 5 p.m. The following papers are down
for discussion :—“ The South Wales Coal Field—Part III.,”
by Henry K. Jordan, F.G.S.; “ The Products of Coal Dis-
tillation,” by W. J. A. Butterfield, M.A., F.I.C.,
A.M.Inst.C.E.; “ Coke Oven By-Products,” by Thos. G.
Watts, B.Sc.; “ The Coal Trade and Allied Industries,” by
R. H. Greaves, M.Sc.; “ Description of a Modern Regenera-
tive Coke Oven Installation, with Notes on the Measurement
of the Gas,” by P. N. Hambly, M.I.Mech.E.; “ Notes on
the Subject of Testing Portland Cement,” by William Alden
Brown, Assoc.Am.Soc.C.E.

Institution of Mining Engineers.

ANNUAL MEETING AT LEEDS.

(Continued from p. 584.)

Rock Faults and Washouts.

The .first paper to be submitted to the meeting on
September 15 was that by Prof. Fearnsides, “ Some
Effects of Earth Movement on the Coal Measures of the
Sheffield District (South Yorkshire and the Neighbour-
ing Parts of Derbyshire and Nottinghamshire).” (See
Colliery Guardian, September 17, p. 567.)

The President (Sir Thomas Holland) proposed a vote
of thanks to Prof. Fearnsides for opening a discussion on
what was certain to be a very interesting and important
question for mining engineers as well as geologists.

The thanks were heartily accorded, and the paper was
afterwards discussed at considerable length.

Prof. Kendall (Leeds) said the hypothesis put for-
ward by the author was not a new one. He was not
prepared to advance any definite opinion upon it, but
he thought before they discussed a question like that,
where they were dealing with a large series of deltaic
deposits, they ought to consider very carefully what
were the conditions of deposition in existing deltas. It
was well known that during periods of slight elevation,
or temporarily stable conditions, the streams which
coursed over deltas altered their courses, and if the
last deposit upon the surface which was now invaded
should chance to be a bed of peat, the stream would
wash it out. These stream channels tended to become
silted up with sand, gravel, and debris from the neigh-
bouring banks. Seeing that these things occurred in
modern deltas, it would be passing strange if they did
not occur in the old deltaic deposits of the coal meas ires.
He did not know from whom Prof. Fearnsides got the
suggestion that the strange inclusions in the coal were
boulders that had been washed down. He (the speaker)
had never made the suggestion. He could quite imagine
that when a stream was coming down through soft
deposits they would have large masses sliding down from
the side and getting overwhelmed. Again, they had the
intermittent action of a stream, at one time cutting into
the coal, and then the wound being healed by a further
growth of coal, and then the stream cutting in some-
where else, so that they got islands of coal. Prof.
Fearnsides had referred to the strange forms assumed.
He was surprised that the author, in his disquisition
upon the compressibility of clays and muds, had said
nothing about the much greater compressibility of peat.
He possessed data from the Whitwood Colliery which
suggested that a seam of coal 3 ft. in thickness was
originally a bed of peat 90 ft. thick. They could well
imagine the disturbances that must take place in any-
thing included in that yielding pulpy mass when it
settled down. Prof. Kendall also stated that he had
for some time been engaged in investigating the ques-
tion of cleat, and he found it necessary to travel far
beyond the boundaries of the South Yorkshire coal field.
The same general parallelism prevailed in all the British
coal fields, and the same features were to be found in
India, China, and Siberia.

Mr. Arnold Lupton remarked that 45 years ago he
made a survey of the Midland coal field for the Coal
Commission. He traced a good many washouts. He
was under the entirely uninformed view that they were
rivers, that washed away the coal and deposited sand
in its place. He had ho ground for that opinion, but
they looked like that, and he found other people held the
same view. One of these washouts, in South Yorkshire,
he traced for a distance of about six miles, and in many
parts of its course it was about two miles wide.

Mr. J. H. Merivale said such faults as he had seen
had certain characteristics. The length was several
times the breadth. Only one seam was affected—not
those above or below it. There was no loss of coal,
which thickened very much on either side of the wash-
out. The islands of coal had the same relative dimen-
sions as the washout itself—they were long in one
direction and narrow in another. All these phenomena
seemed to be consistent with the theory that they were
due to streams which rushed through the deposited
vegetable matter, washing it away and piling it up on
each side, here and there leaving portions of matter
which became coal in time, and bringing down sand
which in process of time became sandstone.

Prof. Henry Louis considered that there were three
possible causes of faults—earth pressure outside the
seams, contemporaneous erosion by streams going
through the swamps whilst they were being deposited,
and—a point to which Prof. Fearnsides seemed not to
have drawn attention—the possibility of eddies existing
in the swamps in which the deposits were being formed.
He took his views to a considerable extent from what he
had been able to see in the extensive mango swamps on
the West Coast of Africa, which he imagined must afford
a very fair analogy to what happened when the vegetable
masses that now formed our coal seams were being
deposited. It seemed to him that in specific cases all
three causes might be operative. He did not think it
was sound reasoning to imagine that one of them
excluded the others.

Mr. John Gerrard considered that there were diffi-
culties in accepting the theory of lateral movement. It
was as if they had three books, and only the middle
one was disturbed. He could not understand that. He

also called attention to cases in which a washout
affected one seam only, and not those overlying it or
below it.

Mr. Ger vase Cook said it was quite easy to imagine
a washout if they considered the action of rivers in China
—the Kiang J, which at times rose 40 ft., and washed
the whole country, or the Yellow River, which had
several times shifted its bed. In the floods in
Manchuria it was no unusual matter to see tons of
stone rolled out of position and carried a mile or two.

Mr. W. D. Lloyd said details of the paper had been
collected from the Altofts collieries, and he had had the
opportunity of discussing with Prof. Fearnsides, on the
spot, his theories as to the material that he described
as rock fault jumble. He should like to add his
testimony to the fact that, on the spot, the actual facts
coincided very closely with the arguments that the
writer advanced in favour of the lateral movement
theory. At the same time, he thought it was wise, as
Prof. Fearnsides said, not to dogmatise too much. It
seemed to him that this was not the only cause—pro-
bably erosion was also responsible. They had at Altofts
an instance, although fortunately it did not cut into the
coal, of a river following a meandering course, and its
bed was now entirely filled up with what was practically
stratified sandstone. The jumble in the Haigh Moor
was a different thing altogether, consisting of masses of
rock which to his mind did not show any evidence of
water erosion.

Prof. Fearnsides replied to some of the points raised,
leaving the rest to be dealt with in writing. He was
not at all sure that the conditions in existing deltas
could be quoted as an exact parallel with that condition
of the coal measures. What he had seen at Altofts,
especially with regard to the micro-structure of coal, had
left him in doubt as to whether they could think of the
making of coal as a process of simple compression of
peat, or mango swamps, or anything now growing on
earth. He quite agreed that there were three causes
for rock faults—possibly more. No case had been shown
him in South Yorkshire which he could accept as
explicable on any other theory than the one he had put
forward, but he did not say that other causes did not
exist. He knew that there were washouts in some of the
sandstones. He took it that it would be very hard for
erosion to stop about 4 in. or 14 in. from the bottom of
a coal seam. He did not accept Mr. Gerrard’s analogy
of three books. He took it that the analogy was rather
that of a pack of cards, all of which had gone forward,
each over the bed below. He took it that at the time
when the rock fault was developed the measures were
approximately flat, and had not been converted into
basin form.

Compressed Air for Coal Cutters.

Mr. Sam Mavor then gave a summary of his paper on
“ Compressed Air for Coal Cutters.” (See Colliery
Guardian, September 17, p. 570 and p. 622 of this issue.)

Mr. Price Abell said that the new Mine Regulations
and restriction of the use of electricity in mines, had
given a tremendous fillip to the use of compressed air for
coal cutting, haulage, pumping, and ventilation. He
heartily supported Mr. Sam Mavor’s advocacy of more
attention to efficiency in the use of compressed air, and
to the use of meters and gauges. Mr. Mavor gave the
loss by leakage in pipes as usually 45 per cent.; this was
quite an avoidable loss, although leaking air in a noisy
mine was not apparent. A simple arrangement of pres-
sure gauges and stop valves would locate this. With a
considerable experience of vacuum pumps, in cases
where the slightest air leak meant spoiling thousands
of pounds worth of sugar, Mr. Abell could not emphasise
too greatly the difficulty and the care that was necessary
to locate vacuum leaks. This had been overcome, and
the same care extended to locate and prevent compressed
air leaks would amply repay any colliery. Another main
cause of loss was the present necessity for 60 or higher
lb. pressure in the pipe lines, whilst, as pointed out in
the paper that Mr. Price Abell read before the Midland
Counties Institute, in 1905, the average pressure used
in the coal cutter in ordinary work was 151b., and
again, in his paper of 1906, this pressure was shown to
vary from 20 1b. ‘‘to as low as 111b.,” whilst Mr.
Reavell, in his discussion on this paper, pointed out that
100-horse power was required to drive the coal cutter
when the pressure was wire drawn down from 60 to
20 lb., whilst only 40-horse power was required to do the
same work if the air was pressed to 20 lb. Whilst the
loss in leaking pipe lines could be avoided by known
means and attention, one was faced with the necessity
of providing high pressure for emergencies, and conse-
quently the difficulty of preventing the loss that followed
by compressing air to 60 lb., and using at a low pressure
of, say, 20 lb. After considerable thought on this
matter, he was driven to the conclusion that the only
way to obviate this was to get over it by some mechanical
means, such as having a light auxiliary motor on the
coal cutter itself, such that it could be turned into
use when jams or chokes occurred. This would, to a
great extent, obviate the great drop from 60 to 201b.,
but still there would always have to be a margin of
pressure to enable the coal cutter to work in the various
qualities of coal, say, of 10 lb. Hence, they must
always look for a loss in the coal cutter being designed
to do the bulk of this work with a lower pressure than