364

THE COLLIERY GUARDIAN.

February 25, 1916.

CURRENT SCIENCE

Hand-Firing Soft Coal.

In Bureau of Mines, Technical Paper No. 80, Hl.
Kreisinger describes methods of hand-firing for power
plant boilers and of handling fire to reduce smoke and
increase heat efficiency, giving detailed instructions
(with diagrams) for correct firing, and showing the effects
of careless firing. Soft .and bituminous coals should be
fired in small quantities at short intervals. The.best
results are obtained when the average air supply over the.
fuel bed is rather less than that necessary for complete
combustion at the maximum rate of burning. In deal-
ing with draught regulation, diagrams are given showing
two methods of arranging for controlling the position of
the damper from the firing floor. The relations of
draught pressure and fuel bed thickness are discussed.
The cleaning of fires and the requisite tools for that
purpose are described, with drawings. (Tinkering, coal
burning in the ashpit, and the combustion of coal are
also treated. Heat losses in a steam plant are
enumerated and shown in a chart.

Unwatering Old Mines.

In course of a paper on “ Mine Drainage,” read by
Mr. Joseph Blight, before the Cornish Institute of
Engineers, the author made some suggestive remarks oil
the subject of unwatering old mines—a matter of special
interest in Cornwall. This branch of mine drainage is
one which must be considered with reference to the exist-
ing conditions on the particular property under
consideration, both in regard to the quantity of water
to be drained and (the size of the drainage shafts. Taking
two cases :—The first, in which the pumping and
winding appliances have been left intact, and. in a fit
state or repair, it would be out of place to consider the
installation of any new plant. If the engine and pump
work are of the Cornish type, the hoisting shaft is provided
with suitable skip roads, and the adit drainage is in
order; then, with properly constructed water skips, more
or less automatic as regards filling and emptying, the
unwatering could be proceeded with on fairly satisfactory
lines. If any difficulties should be encountered by a
pole giving out under water, an air lift could be installed
at a very small outlay to overcome the difficulty.

The second case is that of unwatering an old mine on
which there is no drainage plant of any description, with
the exception of the adits. The first operation would be
to clear the adits. The preliminary pumping might be
done% by an electrically driven sinking pump of the
multiple-stage turbine type if power could be procured at
a reasonable rate from a power supply company close at
hand. This method would give every opportunity to
place the permanent (Cornish) pump work in position.
There would be no necessity for using drop lifts, unless
the electric pump should be lost. If electric power were
not available, compressed air sinking pumps could be
utilised for this work, and the installation of the Cornish
pump work could be proceeded with, without interrup-
tion, the air pump delivering to the lowest plunger
cistern of the Cornish pump. By this arrangement the
air pump would never be subjected to excessive pressure,
and the greatest head against which the Water would
have to be pumped would not exceed 50 fathoms.
Another point in favour of the air pump is that it never
requires more power than that necessary to raise the
water through a height measured from the surface of the
water to the point of discharge; this is not so- with
electrically driven sinking pumps. If a pump of this
class is designed for a given lift, say, 600 ft., and it is
only required to lift, say, 30 ft., then the discharge has
to be throttled down to give a pressure equal to that due
to a head of 600 ft. The total power cost for the same
useful effect will be as 2 to 1, thus giving the advantage
to the air pump. This method may be considered in
preference to the use of electrical power, and it is the
belief of the author that it would be. much more satis-
factory. The cost would not be much in excess of a
transformer house and other expenses connected with
■electrical installation, and the compressor would be
useful for development and other purposes after the
unwatering had been completed. With a multiple-stage
turbine pump, however, some of the impellers could be
removed in the early stages of pumping, so reducing the
power required, say, to that equivalent to 300ft. head,
and, when required, the impellers could be again placed
in position. By this means the difference in power
required would be less than that given above, but it
would be still in favour of the air pump in the ratio
of 3 to 2.

The Three Methods of Sulphate Manufacture on Coke Ovens.

In a paper read by Mr. T. H. Biley before the Coke
Oven Managers’ Association, the relative advantages
and drawbacks of the three methods are stated to be as
follow :—

In the indirect process generally, the advantages are
none, whilst the disadvantages are many, viz. :—(1) A
large number of pumps, - storage tanks, etc., are
required; (2) the plant occupies a large area, and
demands a great deal of supervision; (3) the whole of
the ammonia has to be recovered by distilling the
ammoniacal liquor, and, consequently, a large quantity
of effluent has necessarily to be dealt with, and a great
amount of steam is required; (4) inefficient scrubbing
and loss of “ free ” ammonia, through the scrubber
grids becoming blocked with naphthalene and sediment
from the water used for washing the- gas (if hard water
is used), and at times, should the sprinklers become
blocked,'from the unequal distribution of the water.

In the Hoppers semi-direct process, the advantages
are many:—(1) No naphthalene troubles; (2) less risk
of loss of ammonia; (3) effluent considerably reduced;
(4) sulphate of better and purer quality; (5) less steam
required, as there is less liquor to be treated, and
exhaust steam is used; (6) the plant is much simpler to
work, and is more efficient.

AND TECHNOLOGY.

In the direct process, the chief feature is that pro-
bably more “ free ” ammonia passes direct with the gas
to the saturator. The disadvantages of the system are :
(1) More power is required than in the semi-direct
process, owing to the high speeds of the centrifugal
machines and turbo-exhausters if the liquor made were
treated in a still, then even more steam would be
required; (2) indirect loss of the “ fixed ” ammonia,
owing to the salts crystallising out in the gas mains and
passing away with the tar; (3) effluent from the final
coolers; (4) tar much thicker than in the other two pro-
cesses; (5) trouble in effectually removing the tar owing
to the gases being much hotter; (6) more wear and tear
on a portion, of the plant, due to the presence of
ammonium chloride.

THE GERMAN AND AUSTRIAN COAL
AND IRON TRADES.

We give below further extracts from German
periodicals that have reached us, showing the course of
the coal and iron trades in Germany and Austria :—

Austrian Coal Output in 1915.

The total output from Austrian mines was :—Coal,
16,083,075 tons (15,411,370 tons), an increase of 671,705
tons, or 4'36 per cent.; coke, 1,907,619 tons (2,189,913
tons), a decrease of 282,294 tons, or 12'89 per cent.;
briquettes, 205,041 tons (194,221 tons), an increase of
10,820 tons, or 5'57 per conf. The chief producing
districts were :—Ostrau Karwin, coal, 9,672,770 tons
(8,917,922 tons), coke, 1,849,037 tons, briquettes, 29,641
ions (30,432 tons); Kladno, coal, 2,602,100 tons
(2,439,337 tons); Pilsen, coal, 1,181,326 tons (1,159,087
tons), briquettes, 76,799 tons (68,691 tons); Galicia, coal,
1,647,069 tons (1,738,199 tons); other districts, coal,
1,079,810 tons (1,156,825 tons), coke, 58,582 tons
(69,923 tons), briquettes, 98,601 tons (95,098 tons). The
brown coal output totalled :—Coal, 22,027,151 tons
(23,772,069 tons), a decrease of 1,748,258 tons, or 7'35
per cent.; briquettes, 252,286 tons (230,642 tons), an
increase of 21,644 tons, or 9'38 per cent. Chief pro-
ducing centres : Brux-Teplitz-Komotau, coal, 14,222,441
tons (16,184,728 tons), briquettes, 4,253 tons (2,636
tons); Falkenau-Elbogen-Karlsbad, coal, 3,653,185 tons
(3,507,856 tons), briquettes, 248,580 tons (225,580 tons);
Trifail-Sagor, coal, 1,107,782 tons (1,013,678 tons);
Leoben and Pohnsdorf, coal, 913,512 tons (901,786 tons);
Voitsberg-Koflach, coal, 620,924 tons (628,126 tons);
other district's, coal, 1,509,307 tons (1,545,895 tons),
briquettes, nd (2,426 tons).

Fuel Traffic in Ruhr Harbours in November.

Total shipments to Coblenz and places higher up
river, 433,992 tons (549,308 tons in November 1914);
to places below Coblenz, 18,964 tons (14,486 tons); to
Holland, 93,250 tons (183,054 tons); to Belgium, 18,014
tons (75,724 tons); to other destinations, 35,627 tons
(8,611 tons). Total shipments from : — Duisburg-
Ruhrort, 458,956 tons (661,655 tons); Rheinpreussen,
58,717 tons (66,864 tons); Schwclgern, 23,151 tons
(48,881 tons); Walsum, 50,023 tons (43,812 tons);
aggregate, 599,847 tons (821,182 tons).

Fuel Traffic on the Rhine-Herne Canal in January.

Total shipments in the direction of Ruhrort, 247,149
tons (105,449 tons), of which 32,564 tons (20,905 tons)
were from Arenberg-Prosper, 56,660 tons (24,705 tons)
from the State Collieries, 24,029 tons (14,863 tons) from
Bismarck, 12,728 tons (nil) from Concordia, 9,067 tons
(7,505 tons) from Friedrich der Grosse, 5,509 tons (nil)
from Hibernia, 9,814 tons (nil) from Koln-Neuessen,
9,873 tons (11,573 tons) from Konig-Ludwig, 8,547 tons
(nil) from Konig Wilhelm, 22,245 tons (16,582 tons) from
Mathias Stinnes, 2,535 tons (nil) from Minister
Achenbach, 4,680 tons (2,695 tons) from Nordstern, and
46,850 tons (6,621 tons) from Wanne-We-st.

Iron Market in Upper Silesia.

During January the market was particularly firm, and
all the iron works were very busy, owing to the pre-
vailing opinion that the difficult position created by the
war will be accentuated on the conclusion of peace.
Both pig iron and semis were very scarce, and the selling
prices advanced all along the line in sympathy with the
increases made by the Westphalian associations. Oiher
raw materials have also gone up, and the works- are
further penalised by having to use unskilled labour and
to carry out increased repairs. Sales are therefore small,
and the sales associations are raising prices considerably
for all products. To counteract the decline in the rate
of exchange, the prohibition of exportation has been
extended to bars, hoop iron, and universal iron until
three months after the end of the war, except by per-
mission of the Steel Union, Dusseldorf, who will
examine the prices before granting permits. The State
also stipulates for minimum prices, fixed in the currency
of the purchasing country, so that it is no longer possible
to complete old contracts entered into at low prices and
in German currency. Purchasers will, however, be sup-
plied with the balance of these contracts, when the
prohibition is removed, if they agree to take delivery
within a given period. To assist the Reichsbank in
meeting the increased need for foreign currency, all
foreign debts and payments received from abroad are to
be placed at its disposal. The works are busy meeting
the pressing demand for war material, both direct and
indirect, such as locomotive builders, screw, rivet, and
iron ware makers, railway and military workshops, all
of whom are large buyers. High-grade fine plate is in
special request, and the works have orders in hand to
keep them occupied for months, in spite of the great
advance in prices. The requisitioning of copper vessels

has increased the demand for sheets. In cast steel, it is
difficult to place private orders for delivery in any
reasonable time.

Ruhr Coal Market.

During January, the previous shortage of railway
wagons improved, and the pits were enabled to increase
their deliveries considerably, so that there is every
prospect of the industrial demand being met for some
time ahead. There is, however, a scarcity of small
nuts, which are largely used by the chief industrial
consumers; and deliveries of coke have been delayed
from various causes. The delays in the Rhine traffic
congested the Ruhr harbours, and inconvenienced con-
sumers of waterborne fuel, especially in view of the
depleted state of up-river stocks of steam nuts. In
house coal, the return of milder weather has relieved
the demand, and released large bituminous nuts to the
benefit of industrial users of small nuts. Belgian
mines, which are producing about 75 per cent, of their
normal capacity, are offering smithy coals and anthra-
cite in good qualities. The meetings held to consider
the prolongation of the Rheinische Kohlenhandel- u.
Reederei Ges. m.b. H., have not yet brought the matter
to a conclusion, owing to differences of opinion between
the old members, and with regard to the new members
to be included in the Kohlenkontor, and finally in rela-
tion to the Coal Syndicate.

German Pig Iron Union : New Price List.

The following new price list has been issued for high-
grade pig, for the period from March 1 to June 30 next :
Foundry pig No. 1: Sales district No. 1, 96 mk. (ex
Oberhausen); No. 2, 97 mk. (ex Engers or Wetzlar);
No. 3, 102 mk. (delivery buyer’s station); Nos. 4 and 5,
102 mk. (ibid). Foundry pig No. II.: Sales district
No. 1, 91 mk.; No. 2, 92 mk.; No. 3, 98 mk.; Nos. 4
and 5, 96 mk. Puddling pig, 90*50 mk. Siegerland
steel iron, 93-50 mk. Steel iron low in Ou, 113 mk.
Spiegeleisen (10 to 12 per cent. Mil), 114-50 mk.; all ex
Siegen. Siegerland addition iron, grey, 102 mk.;
mottled, 101 mk.; white, 100 mk., ex Siegen.

American-Made Briquettes in 1914. — The production of
briquetted fuel in the United States in 1914 amounted to
250,635 short tons, valued at 1,154,679 dots., compared with
181,859 tons, valued at 1,007,327 dols., in 1913; the increase
amounting to 68,776 short tons, or 37'82 per cent, in quantity
and 147,351 dols., or 14*63 per cent, in value. The quantity
of fuel briquettes produced in 1914 was the largest in the
seven years for which these statistics have been collected by
the United States Geological Survey. The briquettes which
appear to meet with favour in the Eastern States are of the
boulet type, pillow or egg shaped, and are about the size of
anthracite nut. Those that are practically smokeless, as
they should be, make an ideal fuel for the open grate or
kitchen range, holding their shape until entirely consumed,
and then falling, when stirred, into a pulverulent clinkerless
ash. In the central and Pacific coast States the popular
type of the briquetted fuel appears to be the larger size,
about that of egg coal, for which the raw materials available
seem to be best adapted. More than half the briquetting
establishments use coal-tar pitch as a binder, and if to these
are added those that use asphaltic ^nd gas-tar pitch, binders
of this type are used dn two-thirds of the briquetting plants
that employ binders. The five establishments using binders
other than pitch employ mixtures whose constituents are
principally of vegetable origin. Inorganic binders, such as
cement and lime, have not given satisfactory results, for
although they may be efficient in cementing qualities they
have the serious objection of increasing the ash and of
adding nothing to the combustible matter of the fuel.

Benzol Production at American Coke Plants.—In response
to the unprecedented demand for high explosives, a new
industry, the recovery of benzol and toluol, suddenly sprang
into existence in the United States in 1915. Before the
European war the demand in the United States for these
products was so small, and the price so low, that but one
company engaged in coke making sought to recover them on
a large scale. By the end of 1915 there were 19 new plants
for benzol recovery in operation, and others in course of
erection. Reports made to C. -E. Lesher, of the United
States Geological Survey, by all of the by-product coke
plants in the country, indicate that the output of benzol and
other light oils in 1915 amounted to 13,942,763 gals., in con-
nection with which there were produced 761,256 lb. of naph-
thaline. Some of the benzol recovery plants were in operation
at the beginning of the year, but many were built during the
early months of 1915 under contracts calling for great speed
in erection. Several of the plants are not equipped to separate
the different oils found in the crude, and 7,322,670 gals.,
more than half of the total output, was reported as crude
benzol and light oil, and was shipped in tank cars to
refineries connected with powder works and other chemical
industries. In the 6,620,093 gals, of oils refined at the place
of recovery, there were 4,833,939 gals, of 100 per cent, benzol,
1,315,727 gals, of toluol, and 470,425 gals, of solvent
naphtha. Thirty-one coke-making establishments, with 4,933
by-product ovens contributed to this total, and it is esti-
mated that between 8,000,000 and 9,000,000 tons of coal
were carbonised in the ovens that furnished the gas from
which the oils were recovered. The annual capacity of the
benzol recovery plants now in operation is estimated at over
20,000,000 gals., and with the completion of plants now
building will probably exceed 22,000,000 gals. The value of
these products is indicated by the prices currently reported
during the year. Benzol, normally selling for 20c. or less a
gallon, in September brought as high as 1-25 dols. for imme-
diate shipment, and 65c. on contract; toluol, with a normal
price of 25c., was sold for- as much as 6 dols. a gallon for
immediate delivery, and was contracted for at 4-25 dols. per
gallon. After the war demand for explosives is over, and the
price of benzol returns to normal, serious effort will, of course,
be made to find a market for this product. Shut off from
European competition, the dye and chemical industry in the
United States is now making rapid strides forward. If this
industry after the close of the war is able to hold its own
against the highly-developed foreign competition, it may com-
pletely absorb the output of benzol, and add another source
of income to the coke oven plants.