May 11, 1917.

THE COLLIERY GUARDIAN.

899

naphthalene. The manufacture of the raw material
for dyes would be more rationally carried out on
coking plants than at the dye works. If coke oven
plants would undertake the manufacture of these raw
materials, it would leave the manufacturers of dyes
more opportunity for concentrating on the production
of colours. Mr. Foxwell pointed out that the surplus
gas evolved from by-product regenerative coke ovens
was equivalent to over a million tons of coal per
annum. In a great number of cases this gas was
allowed to burn at a blow-off pipe in order to get rid
of it. It should be possible to transfer this gas to
neighbouring towns by means of high-pressure mains,
as was done in the case of natural gas in the United
States.

In a paper on boiler corrosion, Mr. Basil G.
McLellan, of York, remarked that from the tests
made he came to the conclusion that even the absence
of dissolved oxygen was no guarantee that corrosion
would not take place. That the corrosion was caused
solely by electrolytic action was not definitely proved,
but the evidence was very strong. It was sometimes
recommended that the inside of boilers should be coated
with protective paint. Graphite in a volatile carrier
was frequently used. If the corrosion was due solely
to dissolved oxygen, this might be efficient, but unless
the coat was absolutely perfect—which it never could
be in practice—it was difficult to see how it could do
otherwise than aid corrosion, graphite being electro-
negative to iron.

ASSOCIATION OF MINING ELECTRICAL
ENGINEERS.

At a.meeting of the West of Scotland branch of the
association, on Saturday last, in the Royal Technical
College, Glasgow, papers were read on “ Electric Con-
verting Machinery for Collieries ’’ and “ Some Aspects
of Power Station Centralisation and Inter-Connecting
Systems.”

Electric Converters.

In the course of his paper, Mr. Buyers claimed that
during the last decade the distinctive feature of elec-
trical development had been the rapid growth in the
size of power units and the largely increased capacity
of central stations. To his mind, the future would
undoubtedly see great developments in this direction
in Scotland. In a recent presidential address to the
Institution of Engineers and Shipbuilders in Scotland.
Mr. W. W. Lockie stated that the electric power
requirements of the whole of Scotland could be pro-
vided for by three central stations suitably situated.
By such an arrangement the high-tension transmission
lines feeding the industrial areas could be laid within
easy reach of .colliery districts, and as the power
supply of collieries in this manner had already attained
considerable success in certain districts, it augured
well for the future extension of this system. Mr.
Buyers proceeded to discuss the relative merits of
different types of converters, and said that, on an
average, he believed the following was the correct
method of tabulation for a 300 kw. set, the cheapest
coming first: —(1) Rotary converter, (2) motor- con-
verter, (3) induction motor generator, and (4)
synchronous motor generator. Further, the tabula-
tion in respect of ease and simplicity of operation
might be given as follow's:—(1) Induction motor-
generator, (2) motor converter, (3) rotary converter,
and (4) synchronous motor generator.

Messrs. Henderson, Cowie, McGuefie, Anslow,
Muirhead, Robertson, Kivlen, and Leckib took part
in the discussion which followed.

Centralising and Inter-Connecting Electric Power Systems.

Mr. J. P. C. Kivlen, electrical engineer to the
United Collieries Limited, who contributed this paper,
remarked on the fact that within 500 yds. of the centre
of the city of Glasgow a large public park covered an
area of proven coal of high calorific value. That par-
ticular park was bounded on one side by a large river,
in addition to which there was a weir which might be
used for driving generators direct. In deference to
public opinion, Glasgow Corporation had decided that
the park must not be destroyed, but in his (the
author’s) opinion a few undulations from underground
workings would enhance the appearance of the place,
which at present was rather flat and uninteresting.
That particular area of coal would require to be
worked some day, and no one appreciated that fact
more than a colliery manager. Why, then, should
they not work it now? The one way to conserve the
coal supplies of the nation was to use the coal econo-
mically. The economical generation of electricity
from steam meant that the power house should be as
near as possible to the pit mouth. Given the ideal
site, the ideal composition of the power house must
be dealt with. Primarily, the destructive combustion
of coal could not appeal to the engineer or chemist.
Its intrinsic value was high, and should be observed
from the point of view of its utility in this respect, and
not entirely on the calorific value. It appeared to
him that a plant operated by large gas engines
running in conjunction with a by-product plant would
prove the most efficient.

Partnerships Dissolved.—The London Gazette announces
dissolution of the partnership of W. H. Pagett and T. G.
Pagett, trading as W. H. and T. G. Pagett, coal and crate
wood merchants, Stourport; and of A. E. G. Braithwaite,
J. H. Humpfiryes, and A. Anderson, trading as Braith-
waite and Kirk, engineers, 117, Victoria-street, West-
minster, Crown Works, West Bromwich, and elsewhere.

Proposed Coal Monopoly in Russia.—A conference was
held at the Ministry of Commerce, Petrograd, on April 24,
to discuss the question of the introduction of a coal mono-
poly. It is proposed to place at the disposal of the Govern-
ment all mineral combustibles, and to regularise their
distribution. The representatives of the industry, who
were present at the conference, made no protest against
this scheme, which, it is believed, will be realised in the
middle of May.

SOME ASPECTS OF THE PROBLEMS
OF FUEL ECONOMY.

By E. Crowther.

At the present moment, when the vital importance
of the question of fuel economy is now generally
realised, and its study has been recommended and
initiated by the country through the Research Com-
mittee, it occurs to the writer that the views of one
who, though keenly interested, is yet not directly
concerned, might be of interest to others whom it
touches more nearly.

It has long been recognised that the majority of our
present methods of utilising coal, whether for the pro-
duction of power or heat, are unsound and wasteful,
and, in view of the fact that the whole fabric of our
national prosperity depends upon our coal resources,
little less than criminal; though undoubtedly any
radical re-organisation of our present system can come
but slowly, marching with the progress made in the
various branches of engineering affected.

As in many other trades and industries, the war has
had a very valuable and stimulating effect on our work
in this connection, particularly by bringing home to
the country its absolute dependence on coal, and the
necessity for economy in its use. Even the rise in
price has not been an unmixed evil, as it has caused
power users to put forth their most strenuous efforts
to improve the efficiency of the plants under their
control; whilst it has taught the domestic user (one
of the worst offenders against the principles of
economy) to rely more upon alternative schemes of
heating, such as the use of coal gas, and coke-fired
steam or water radiators, instead of the wasteful burn-
ing of raw coal in inefficient grates.

On the larger scale, the problem of power production
is complicated by the introduction of the financial
element. For example, where large powers are
needed, as in the case of a central electricity station,
it might be possible, by the use of an internal combus-
tion plant in place of a steam turbine set, to reduce
the coal consumption by, say, one-third. Yet if this
reduction in the fuel charges is counter-balanced by
increased first costs, maintenance costs, and uncer-
tainty of operation, the natural consequence is the
adoption of the steam plant, and a loss to the nation
of the coal, which might have been saved had the
internal combustion plant been selected. It is easy
to suggest the remedy, though less easy to carry it
out. Obviously the reliability of the latter plant must
be improved, its capital cost and the cost of main-
tenance diminished, and its period of life prolonged,
until it can compete in these respects with its rivals.

It is unlikely, in this country at any rate, that the
steam turbine will ever be displaced in high power
work by internal combustion engines of the recipro-
cating type, on account of considerations such as those
just instanced, though no doubt the appearance on the
market of a thoroughly reliable gas turbine would com-
pletely alter the situation. This is by no means an
impossible contingency, as a considerable amount of
experimental work has already been carried out along
these lines, and progress has been made in spite of the
many difficulties in the way. The great mistake of
the past has been to regard coal solely as an agent for
the production of heat, and to neglect very largely the
importance of the various products which may be
obtained by scientific treatment of the raw material.
By carbonising the coal according to one or other of
the various systems now in vogue, provided that suit-
able markets can be found for the products, not only
may its commercial value be increased, but also a very
real gain secured to the nation as a whole, in respect
of the conservation of supplies, the cessation of atmo-
spheric pollution, and the home production of several
articles of vital necessity, at present imported from
abroad. A very striking instance of this last-
mentioned point is furnished by our need of oil for
power and other purposes.

The carbonisation of a very much larger portion of
the coal consumed than is so treated at present is
delayed solely by the difficulty of expanding the
markets concerned, which is in part due to the inade-
quate education of the average power user in the
benefits conferred by the use of so-called “ manufac-
tured ” fuels. If the markets were to be artificially
enlarged, for example, by the total prohibition of the
use of raw coal as a direct fuel, it is probable that the
price of coke and gas for raising steam and for use
in internal combustion engines would fall to such a
figure that it would become considerably cheapen to
obtain power by their agency than by the direct use
of coal as practised at present.

Of the two systems of carbonisation at present
obtaining—viz., in coke ovens and in gas works—
neither was primarily intended for the purpose of
making the best possible use of the coal distilled, but
was laid down to produce one particular by-product
for a special object, and consequently neither attains
perfection with regard to maximum fuel economy.
There is, however, nothing antagonistic in the two
systems, and the tendency of modern practice is to
increase the similarity between the results obtained.
It is likely that the two systems may be run in con-
junction with one another in the future, the gaseous
products of each being pooled, and used indifferently
for lighting, heating, or power production. A step in
this direction has already been taken by Leeds, whose
gas works now takes a portion of the surplus gas from
a neighbouring coke oven plant, for use along with the
gas which it produces itself.

Another process for the treatment of raw coal, which
has been strongly advocated for some years in certain
quarters, is that of low temperature distillation. By
this method, it is claifned, not only is a large quantity
of valuable oils recovered, but also the residue from
the distillation is a smokeless, easy-burning fuel,
superior to coal, and especially suitable for domestic
use. To make the industry a financial success, how-
ever, it appears to be necessary to dispose of the fuel

at a price as high as that of coal—a difficulty well nigh
insuperable without legislative aid in some shape or
form.

A word on the subject of the gas producer would not
be out of place here. Except for a few particular
uses, the gas producer cannot be said to represent the
highest pitch of fuel economy, as by its agency but a
very small part of the possible by-products in the coal
is retained, and in many types the fuel is burned
entirely. Its efficiency is admittedly higher than that
of a steam plant, yet, at its present stage of develop-
ment at least, it can only be said to have a restricted
field, namely, for powers between 100 and 2,000 horse-
power ; since, below the lower limit, coal gas can com-
pete with it successfully, and above the upper limit the
steam turbine, whilst even within this range it is by no
means free from serious rivals when the question to be
decided is not coal, but cash.

For certain uses, however, it is unrivalled, both on
commercial and economic grounds. For example,
many waste products, such as sawdust and vegetable
refuse, may be gasified successfully and efficiently in a
producer, as may also low grade coals, unsuitable for
other purposes; whilst, as a means of disposing of
surplus gas works coke when the market is slack, and
of adding to the make of gas without employing more
coal, the water-gas producer is very valuable.

Centralisation of power appears to be a growing
tendency in electrical circles, and is most certainly a
sound proposition, for, up to certain limits, the greater
the size of a power station, the lower the running costs
per unit of energy. Centralisation of coal distilling
plants, too, would appear to possess equal advantages,
especially if run in conjunction with large generating
stations, and perhaps blast furnaces as well; and this
is one of the possible developments which the future
may see. Radiating from the centres of large circles,
situated if possible in the immediate vicinity of coal
mines, would be heavy transmission lines of cheap elec-
trical energy, for universal power purposes, and high-
pressure gas mains for domestic and industrial heat-
ing purposes. The generators would be driven by
steam turbines, fed from boilers fired either with
surplus coke, coal gas, or blast furnace gas; the coke
produced by distilling the coal would be used in the
blast furnaces, and the oils for general industrial pur-
poses, driving motors and aircraft, and perhaps also
for ship propulsion in Diesel engines. The only raw
coal used would be on board ship, and perhaps also for
railway work in cases where electrification was imprac-
ticable.

Such a scheme may seem visionary, and would pro-
bably be possible only under State control, but the
matter is urgent, and centralisation and the abandon-
ment of the use of raw fuel seem to offer the only
means of effecting radical economies.

THE DAVIS-FURNTON BELL.

Referring to the description published in our issue
of April 13 last (page 729), it should be mentioned
that, when the bells are employed in noisy places,
such as haulage engine houses, it is desirable to indi-
cate the ringing in some other way than by sound.

■S'

■

With this object, the makers have attached to the
armature—as shown in the accompanying illustration
—a flag, which vibrates with the striker of the gong,
but ceases immediately the contact is broken and the
bell stops, so that the conflicting of two signals is
precluded.

Irish Coal Fields.—The recent decision of the Govern-
ment to build a railway connecting the Wolfhill Colliery,
in Central Ireland, with the Great Southern and Western
Railway at Athy, has revived interest in a scheme for direct
railway connection with the Castlecomer Collieries, which
lie to the south-west of the same seam. Four fully-
equipped collieries in this region are drawing coal to the
extent of about 70,000 tons a year, but their output is
limited by the absence of railway connections and by a
cartage charge of 8s. to Carlow Station, 11 miles east, and
of 10s. to Kilkenny, 15 miles south-west. More than one
attempt has been made to give railway communication to
this district. The latest proposal is for a railway of 12£
miles from Clinstown, a point about 3| miles south of
Ballyragget, on the Maryborough and Kilkenny branch of
the Great Southern and Western Railway, to Castlecomer
and Crettyard. This would follow the natural lie of the
country.