February 2, 1917.

THE COLLIERY GUARDIAN.

231

FUEL ECONOMY.

The question /o£ fuel economy was discussed lat a meet-
ing of the Manchester section of the Institution of
Electrical Engineers on Tuesday last, Mr. Julius Frith
dealing with the matter from the electrical engineer’s
point of view, whilst Mr. Drummond Paton treated the
matter from the mining standpoint.

Mr. Frith said it was becoming increasingly obvious
that coal was not only a fuel, but in reality a storehouse ■
of many very desirable products, of which thermal.
energy was only one, and not necessarily the most .
important; and consequently to use it as a fuel alone,
'by throwing it on .the fire, not only wasting all its other
products, but turning them into the atmosphere to
become’ there ■ a source of pollution, harmful to life, and
costly to industry, was an economic sin which ought.,
never 'io have been allowed, and which, in the face of
the present urgent need for economising our national
resources, ought to be prevented, if necessary,' by the
State. After describing in some detail the. various
by-products of coal, Mr. Frith went on to suggest that
indusitries which had coal as their origin should be
collected round the collieries, thus effecting consider-
able saving in connection with the handling of the coal
itself and the by-products. By way of example., he
quoted am electrical supply undertaking of 12,000 kw.
installed and capable of turning out, with a reasonable
reserve of pliant and a load factor of 25 per cent., about
20 million units per annum. Such a station, if
equipped with turbine engines and water tube boilers,
fired direct with coal, would consume about 22,500 tons
per annum. Suppose, then, the station were run in
connection with a battery of coke ovens, the surplus gas
from which was used for gas firing the boilers.. Owing
to the slightly higher thermal efficiency of gas over
coal-fired boilers, say, 80 and 75 per cent, respectively,
and the greater ease of getting up steam in those, boilers
effecting a reduction in banking losses, the net thermal
efficiency of the station might be increased from 11*4 to
13’6 per cent. Taking coke oven gas as 450 British
thermal units per cubic foot, and 32 degs. Fahr., and
30 in. barometric pressure, higher calorific value, and
assuming that one ton of coal made 10,000 cu. ft. of gas,
and used 6,000 of those for heating itself, the station
would have to coke about 280,000 tons of coal per
annum. He estimated that about 150 ovens would be
required, and in coking 280,000 tons of coal a revenue of
12218,700 per annum would be drawn from products
other than gas. On the expenditure side, he would
allow 150 ovens, with coal crushers and bunkers, eleva-
tors, water-cooling plant, and recovery plant, at a cost
of £225,000; 10 acres of land, at £50 per acre, £500;
and for extra railway sidings over what would be
required for the coal-fired boilers — not forgetting the
saving in ash handling plant—‘the sum of £1,500, making
a total of £227,000. The prices he quoted were not
present inflated war prices, nor were they as low as
some pre-war periods, but were an estimate or forecast
of what might reasonably be expected after the war.

The total annual cost he would estimate' as follows :
5 per cent, interest on £227,000, £11,350; 10 per cent,
maintenance and depreciation on £226,500, £22,650;
labour to handle coke ovens and recovery plant at 2s.
per ton coked, £28,000; reagents used in the recovery
process costing about lOd. per ton. of coal coked,
£11,700; sundry and establishment charges at Is. per
ton coked, £14,000; and 280,000 tons of coal at 8s. per
ton, £112,000—a total of £199,700. The sale of pro-
ducts other than gas would produce £218,700; 22,500
tons of coal not burnt under boilers at 8s., £9,000; and
the saving of_ga>s over coal firing at 6d. per ton of coal,
say, £600—a total of £228,300, thus showing a saving
of £28,600 per annum, or 0-34 per unit on the 20 million
' units sold. On the other hand, gas producers of the
Mond type could be installed to completely gasify the
coal to its final ash, with a saving over coal firing of
£1,300 per annum.

Low-Temperature Distillation.

Against the first scheme, the treating of coal in coke
ovens, it might be urged that the market for metal-
lurgical coke was (strictly limited by the demand for that
product by the blast furnaces, and that a state of over-
production would soon be .reached. That was, of course,
true, and it therefore remained either to combine coke
ovens and Mond-type producers, limiting the production
of coke to the requirements of the iron and steel trade,
or else gasify the surplus coke from the coke ovens in
producers, for which purpose it formed an excellent fuel,
yielding about 160,000 cu. ft. of gas, and la calorific value
of about 120 British thermal units per cu. ft., as well as
60 lb. of sulphate of ammonia per ton. Another, and
possibly a better, method was the manufacture of semi-
coke by processes of low-temperature distillation, which
gave a practical solution of the domestic fire difficulty,
because soft coke of that kind was said to burn satis-
factorily in open grates. Some eminent authorities had
gone so far as to state that 'that fuel was so satisfactory
that a period ought to be fixed by law, after which it
should be illegal to burn raw coal at all. Then, the
burning of coke in a steam boiler had not received the
attention it deserved, and he knew a case of a fair-sized
works being supplied with steam from a battery of
Lancashire boilers which had been fired for years with a
mixture of coke breeze and coal slack in the proportion
of seven or me lormer to six of the latter. That had
given excellent results from both a practical and finan-
cial standpoint, as the pre-war prices were 2s. 3d. and
10s. 4d. per ton of coke and coal respectively. In
London, too, gas coke alone had been used with success
for firing Lancashire boilers, and considering that
apparatus had been used which was designed and
developed entirely with a view to burning coal, with
only the addition of forced draught, it was extremely

likely that even more' satisfactory results would be
obtained if the subject were more closely studied, and
a furnace 'specially designed for that class of fuel. 'The
lines that design would take would be in the provision
of a better and more dirigible forced draught, a better
means of mixing and firing the fuel, provision for a con-
siderably increased depth of fire, and by moving fire-
bars and possibly steam jets (though these were objec-
tionable in other ways), the provision of some effective
means -of dealing with the increased clinkerihg of the
coke fuel. Even if. none of those innovations were
adopted, a vast improvement might be effected in, one
might say, nearly all industrial boiler houses by a more
scientific handling of the problem of combustion. He
felt sure that, as the increasing cost of fuel forced that
more and more on the attention of -the owners of such
plants, boiler house foremen would be appointed who
would have a. sufficient knowledge- of chemistry and
physics to enable them to direct the activities of the
stoker, and check the results by analyses of the fuel and
the flue gases. ■

Mr. J. Drummond Paton said it was a human failing
to desire to make money quickly, and until the engi-
neering, and particularly the electrical and allied trades,
as a community forced upon the nation the considera-
tion and utilisation of coal, we should still! have that
basis of our national prosperity wasted in millions of
tons, as it had been in the -past. • Two features to which
he wished to draw particular attention were, the national
loss of coal left in the mines or thrown away at the pit
bank, and the huge untouched reserve of coal which had
been partly destroyed by a system of mining that would
•be- absolutely criminal if allowed to continue. He was
no believer in the condition which left commercial
returns to a voluntary control, and therefore if legisla-
tion permitted our ’coal to be used as it had been in
■the past, our errors were a national misfortune, not an
offence; so that producers and consumers were equally
to blame, and our present work was to supply and
enforce the remedy. By means of slides, Mr. Paton
explained the composition of various Lancashire steam
coals, Yorkshire slack, cannel coal, and Chesterfield
and Nottingham district coal. Those coals, he went on
to say, had been the main basis upon which our engi-
neering industries had been built, but in the develop-
ment of mining, several seams had been discovered
which were neither high-grade coal, nor yet an abso-
lutely useless shale. They were invariably classified as
bastard cannels or coal. Some of those coals had a
classification which brought them very closely into the
cannel zone, and if that matter were mined and supplied
to a steam user, he would complain that he had not gone
in for a tar distillation works, but wanted coal for boiler
purposes. In the very words of that complaint lay the
secret and value of the material which, in the past, had
been considered as valueless; and when many Lanca-
shire mines were in full operation, mining house and
steam coal, those coals were available, but the pits had
been abandoned, leaving, in many cases, large reserves
istill unworked. In their own district there were several
mines with seams of that type which only required to
be opened out. It was simply a question of calculation,
as to what extent the supply of that material, in addition
to the existing supplies of steam and hard coal, would
affect the actual market.. To do that there was no need
to. interrupt the present methods. . What was wanted
was a national investigation of the reserves to which he
would draw attention, and a means of application and
use of coals under the new conditions that had developed
and which must be considered in the . future if we
wished , to establish our commercial supremacy.

He also- drew attention to. the fact, that, whereas'in
the past our desideratum had been a hard dry coal, the
development of modern engineering, distillation,
recovery of oil, and other features which had been
brought before technical institutions, had shown that
coals which in the past had been- rejected and left in
the mine would in the future possibly be worth more
than was now paid for the best Lancashire is team slack.
Another feature which must be noted by the engineer-
ing and allied industries was the fact that whereas in
the past mines had been worked with a view to producing
lump coal, in modern means for the utilisation of coal it
had been proved that lump coal was unnecessary for
high efficiency, and, as a matter.of fact, it.had become
a truth that to get the maximum value out of coal, at
least in a furnace system, it was first of all necessary to
powder it and fire as dust. The supposed value of the
individual or human element in the mine was the extent
of round or lump coal he could recover in excess of
machine systems, but now that it had been discovered
that lump coal was unnecessary, we could go to the
limit in providing a machinery system for its recovery.

Dealing with the question of hydraulic stowing, he
remarked that the process, which was first taken up in
the States, and then in Germany, percolated into this
country about 10 years ago, and if the holocausts which
had occurred through terrific gas explosions, and the
terrible national- waste which had gone on for genera-
tions, were to be arrested in this country, it was one of
the means by which the desired end could be attained.
' Beneath the bulk of large Lancashire cities there was
abandoned coal which would run the power stations of
those cities for centuries, and it was surely time that
not only the mining industries, but the community in
general should consider a means by which that waste
could be utilised. What could be done under a
Stadhaus in Germany on the Rhine, could be done
under the public halls-in Manchester, Bolton, Bury, and
Wigan. In simple language, the method of stowing was
to convey into the mines a mixture of shales, gravel,
sand, and other suitable rubbish, and fill up the cavity
from which the coal had been extracted. It was
admitted that for the efficient mining of coal on an
economical basis it was necessary to leave as wide a
space as possible between the actual coal face and the

goaf or cavities from which coal had been extracted for
transport facilities. By reason of 'the advance of the
face, the foregoing was evident when one considered the
fact that cutter machines, transport systems, and means
of rapid extraction.and removal had to be placed between
the actual coal face and the goaf space. The simplest
consideration and investigation of mining subsidence
would show to the layman that the nearer we could
retain the superstrata in its original condition, the less
would be the possibility of fissure running out from the
excavated area to the surface and producing subsidence.
Consequently, if the actual removal of the coal were
followed up by a replacement with a suitable material
which filled up the cavities where the coal was removed
from, one could extend the distance between the goaf
and the advancing face to a maximum, so. that by trans-
port systems, etc., maximum efficiency could be main-
tained. Therefore, for the installation of machinery in
coal mines, and the consequent .improvement in output,
also the receipts of recovery, diminution of explosions,
diminution of trouble in ventilation, diminution of sur-
face damage, and the deletion of the enormous burning
heaps which were the funeral pyres of the past genera-
tion of mining engineers, there was only one way out,
and that was the efficient use and application of. such a
method of stowing. The destruction of superimposed
coal had been enormous by gluttonous use, inefficient
methods, and criminal mining, and again there were
innumerable seams which lay close to the surface which,
if opened out under the existing conditions, would-imme-
diately produce subsidence which would bring in surface
water. By hydraulic stowing, it was possible to- pack
these seams so closely that no- water came in from the
surface; -'and a successful application of this method
and an illustration of the claims made by the speaker
was afforded by the present mining system in vogue
under the Olyde, where a company -had established a
most successful plant, and was adding further installa-
tions.

In a paper read before the Institution of Mining Engi-
neers at Manchester in 1913, he had defined a lay-out-
system for the operation of a mine, and.it was a well-
known fact that at the Koenigen Louise Mine in
Silesia, an output had been maintained from one coal
face 200 yds. wide which was equal to the output-of
some of the largest collieries in the Lancashire area.
He would say again that what had been done in Silesia
could be done in the same way in the Lancashire coal
fields, on the basis that union labour would, admit the
claim and advantage of machinery, and that the British
colliery owners would listen to the pleadings of reason
and the advantages which would accrue from the appli-
cation of scientific mining, and the extraction of coal
for a national purpose. Accepting that they had defined
ia means of mining, and granting the necessity of the
mining of all coals in the seam, the next feature was to
provide a means of utilisation which would pay an
economic return, and procure to the country a maxi-
mum value from her original resources. In many of
the lower grades of coal there was a large amount of
resinous or -pitchy matter, and there was a class of coal
of a greasy, sticky nature which was useless in the fur-
naces. Past methods of utilisation destroyed that, the
most valuable element in the coal, but future systems
of utilisation would accentuate the value of that item,
and recover it as their main purpose in the method by
which the coal would be used.

MIMING INDUSTRY AND MILITARY SERVICE.

To the Durham County appeal tribunal the Tyne Coal and
General Supply Company, South Shields, appealed for the
exemption of a foreman. It was stated that - the company
contracted for the supply of coal to the military in and about
the borough. Judge Greenwell, presiding, said the company
could not expect to retain a man of 29 years who had been
passed for general service. It was the. duty of everybody
who h ad anyone of th ait age in his employ to do hiis level
best to find a substitute. The appeal was dismissed.

It has been necessary for Mr. Herbert Greener, agent for
Messrs. Pease and Partners Limited, to write to the military
representative of Crook tribunal asking that it should be
made perfectly plain -that the firm comd not select men for
substitution. The whole question lay in the hands of the
military authorities. The military representative has
endorsed this statement, and . has pointed out that a firm
could not take out any man and say, “ Go into the Army.”
It could say, however, that the man provided ajs a substitute
was not satisfactory, in which case the man who was being
substituted could not be sent into the Army. The tribunal
was empowered to send reinforcements into works, and to
give men conditional exemption, 'subject to their taking up
work of national importance. It wals that step Which had
caused some feeling -at Messrs. Pease Is Bankfoot Works. The
men who li.ad gone to Bankfoot were reinforcements, not
substitutos.

At the Whitehaven tribunal, Cumberland, a pumpman land
mines fitter, aged 35, married, applied for absolute- and con-
ditional exemption. He had worked in the mines since 1913,
firlst in the iron cite mines, and then in the collieries. He was
now Working at William- pit, Whitehaven. Conditional
exemption was granted.—Mr. T. Foster, of Newcastle-on-
Tyne, applied for the exemption of a mining engineer in the
Whitehaven district. Applicant explained that he had been
asked by the Ministow of ’Munitions to look after his interests
as regards the working of a certain mine. Mr. E. L.
Nanson, the Earl of Lonsdale’s agent, also appeared on
behalf of the engineer referred to, who had the looking after
of 20 iron ore lettings on the Lowther estate. Conditional
exemption was granted for six months.

An appeal for the colliery -bill clerks of a large firm was
heard by the Auckland Rural tribuanal. It was contended
that the work involved at least 12 months’ training. Exemp-
tions, pending substitution, were granted. — At the same
court, a local colliery owner and farmer from the Fir Tree
district applied .for a man in charge of about 100 horses and
pit ponies, and secured conditional exemption. The court-
pointed out, at the request of the agricultural representative,
that a man who was being substituted could not be called up
until toe substitute was proved to be satisfactory.