1110

THE COLLIERY GUARDIAN.

December 8, 1916.

getting all that was there, and it did not matter whether
it was 2| or 3, so long as they were recovering it. On
the question of the point of saturation of the oil, they
were all at sea, because they used different tests. Mr.
Wilson would say, work up to 3| per eent. saturation,
but he did it by a certain test. They might do it by
another test, and get another saturation, and the results
would be all at variance. That was why he asked that
the association should form a committee to go into these
questions.

Mr. Wilson said the water trouble to which Mr. Green
referred puzzled him very much. They had had a
greater quantity of water, some two or three years ago,
and they got that out easily enough with the same plant.
He wished he knew why they could not get it out in the
case referred to in the paper. The only difference was
that the oil in that case was of a worse quality than in
the previous instance. He was afraid they had not
gone much into the question of the phenols, and whether
they were an asset or otherwise he did not know. Speak-
ing generally about the quality of the wash oil, their
experience was that if they had a sufficiently low tem-
perature, they could work with a very poor quality of
oil. The drawback to that poor quality was that they
got deposits of free carbon, anthracene, and so on, in
the scrubbers and elsewhere, and had to clean out now
and again. If they were on a sufficiently low tempera-
ture, they got the recovery of the benzol all right. He
was working up to 1*100 gravity—they found it paid
them to do so with the quality of oil that they were
getting now. They had not taken up the question of the
phenols in the crude benzol and the spent oil. They
once thought of recovering the pyridene from the crude
benzol, but they found there was not a great deal in.
They found the chief amount just after the change, the
oil naturally coming from the wash oil, but it dwindled
to next to nothing. He had not quoted any figures as
to the loss of benzol in the return gas, for the simple
reason that he did not consider they were worth much
with the tests that they had at present. The tests were
very exhaustive, but he did not think them good enough.
They could not get an average test that was worth
much. The results never seemed to tally near enough
with what they actually got in practice.

Mr. Green said he omitted to mention the first test
that they had, distilling up to 135 degs. Mr. Wilson
distilled in the flask with the four pears on, but they
simply distilled in an ordinary Wurtz flask with the
thermometer opposite the branch tube, and distilled uj
to 135 degs. The rich oil gave a gravity of 0*921. At
120degs. they had 37 per cent., and at 200degs. they
had 79 per cent. A member of a coke oven firm sug-
gested to him that possibly what they were losing in the
return gas was of a higher quality than the other, a
richer benzol. They made a test on that, and they
found, testing it in the same way, that at 120 degs. they
got 39 per cent.—both of which approximated very
closely to Mr. Wilson’s figure—but at 200 degs. they
got 88 per cent. It gave a slightly higher yield at
200degs., and did not bear out the theory that was pro-
pounded. In connection with rectification, and as to
whether it would pay to make 60’s or 55’s, he should
like to ask how the steam consumption would be affected,
and what was the steam consumption in the ordinary
crude plant.

Mr. Wilson said he had some figures of steam con-
sumption, but not with him. He could give them to
any gentleman who was interested. Of course, if they
distilled a product that gave a residue of 25 per cent.,
they naturally had to use more steam for a given yield
of benzol. They had not found that they got more
toluol in winter than in summer. They did get more
benzol, and also more sulphur in the benzol, showing
that at lower temperatures they were recovering more
carbon disulphide.

Collaboration Suggested.

Mr. J. W. Lee (Grassmoor) said the discussion
reminded him of when he was a member of the gas pro-
fession. He would suggest that the two professions
would get most good from each other if they did not
jibe at one another, but remembered that, although the
gas engineers might be children in this matter, they, as
coke oven managers and associate members, had much
to learn from the gas industry. That was borne out by
the fact that one of the points made in the paper was
the advisability of metering. Metering was a point
'which had always been very much to the front in gas
engineering. Every part of a plant, the water supply,
and so on, was all metered. He would ask any member
present if he knew by meter how much water he was
supplying to his ammonia scrubbers. He did think
that, at this time in the nation’s history, the two pro-
fessions should remember that they were both out for
the same end, which was to supply those things which
the country very much needed, and if in any way they
could help one another, they ought to do so. He felt
that they ought to insist upon the importance of meter-
ing. He agreed most fully with Mr. Wilson that every
point of doubt that they could eliminate, the better it
was for them, and if they could do it in this way, they
ought to. In connection with naphthalene, he was
reminded of discussions on the subject from a gas distri-
bution point of view 10 or 15 years ago. The general
result of them was that the fact remained that, where
the conditions seemed to be absolutely identical, that
which was a trouble in one case, was not in another, and
that which was a remedy in one case, was not in another.
They must bear in mind that benzol plants varied very
greatly. Where one man found by experience that he
must work to a certain top temperature, such as Mr.
Wilson’s 140degs., another could work at 110degs., or
108degs., which was his own experience. In order to
get exact knowledge as to the varying conditions of the
plants, they must put on paper the whole of the dimen-
sions, the steam conditions, even the size of the houses
in which they were worked, and the ventilation, and

other particulars. What he meant was that one man’s
temperature would not do for another plant. Of course,
they gained a great deal by hearing another man’s
experience, but, when they went back to their own
plants, they must not be silly enough to think that they
could apply the other man’s temperature to them. If
they did, they would have a great deal of trouble. In
his experience, he did not get water so long as his tem-
peratures were just over 100 degs. Cent, for top tempera-
ture. They never got water except under such condi-
tions as leaky taps. As to the question of testing crude
benzol, he suggested that the temperature of 167 degs.
had come from the fact that solvent naphtha was sold
at a dry point of 167 degs. Therefore, they had got into
the habit of testing the crude oil up to 167 degs. He did
not say the figure was right, but it was natural to adopt
it. Mr. Wilson did not tell them the amount of fresh
oil circulated per gallon of benzol recovered, nor the loss
of creosote per gallon. In the speaker’s case, taking
figures for a year’s working, it was 0*096 gal. of fresh
oil, and 0*044 gal. of creosote. On the question of wash-
ing, Mr. Wilson quoted figures of 3| per cent. He
worked that out to 7*8 per cent, by weight. In the
speaker’s case, again taking figures over a year’s work-
ing, the percentage of d.o.v.* used was 3 per cent, by
weight—a very different figure. He had been wonder-
ing whether some of the high percentage of acid
required might not be due to the high top temperature,
at which Mr. Wilson worked, bringing in something
which might need a great deal more washing up than
they got with their lower temperature. Mr. Bishop
considered shale oil better than creosote oil for washing,
but his own experience with shale oil was exactly the
opposite. It emulsified, and increased their water con-
tent very greatly, until they got up to 40 per cent, of
water in the wash oil. It seemed to him that naph-
thalene was an exceedingly good medium for removing
benzol. He was certain that it was not a disadvantage
from a scrubbing point of view. The trouble was that
they had to eliminate it i'n the after process.

Temperature and Acid Consumption.

Mr. Wilson was glad that Mr. Lee agreed with him
with regard to metering. He often thought that he
should like a meter on the ammonia liquor going to the
still, and in other parts of the plant. It all came to a
question of narrowing as much as possible the variable
factors in a plant. With regard to the fresh oil, they
circulated about 100 to 120 gals, per ton of coal car-
bonised per day. He would rather not quote any figures
as to the loss of creosote. It was rather high with them,
but he was not satisfied with the figures that he got out
some time ago. He certainly thought that the tempera-
ture had some effect on the expenditure of acid, but at
the same time, when they were washing for pure, he
did not think they could do without a considerable
amount of acid. He certainly thought that one draw-
back bo working at high temperatures was that they got
certain products over which increased the amount of
acid required in washing. He was rather disturbed
about the amount of acid he had to use in washing for
pure, but, as the result of exhaustive tests, he was
quite sure it could not be lowered any more. They had
a very good test on their pure, and never got any com-
plaints about it. The Government specification was
fairly stringent. He was glad the Government did not
insist on the acetone test, because he thought the results
they got with acetone were not very good.

Mr. B. W. Haigh (Barnsley Main) said he would like
to hear, from someone who had considerable recent
experience, what percentage of finished products one
might expect to recover from 65 per cent, crude. He
had heard figures of 78, and even 82, quoted, but other
people told him that 72 was the absolute maximum.

Mr. Wilson said from 70 to 72 was about their figure,
but, as he had pointed out, although they had been
frequently at 65 per cent., recently it was not a true 65
under their present conditions, because they only got
75 per cent, of light and heavy oil from their crude
benzol. With true 65’s, they ought to get at least 85
per cent.

Mr. Thorpe (Barugh) believed that a heavy oil was
best for absorption, but they must consider the thicken-
ing of the oil afterwards, its action on the scrubbers, and
so forth. Consequently, he was inclined to go part way
with Mr. Bishop, and mix along with a heavy oil a
Scotch oil so as to obtain an oil with a gravity of some-
thing like 1*060. The gravity of the Scotch oil was
under 1, and the two combined kept the boiling point
of the oil up. This prevented the distilling of the
creosote in the crude still, and also assisted the pumps.

Mr. Wilson, referring to the relative temperature of
the wash oil and the gas, considered that there ought not
to be a great deal of difference. A friend in America
informed him that they put in a refrigerator plant for
their oil, and that was one of the first troubles. They
found the temperature of the gas so much higher, and a
lot of water in their oil. Another thing was that on the
cooling coils they got a deposition of naphthalene, and
that interfered with the interchange of the temperatures.
With regard to the wastage and thickening of the wash
oil, he thought it was a good idea to wash preliminarily in
a washer in which they allowed the oil to thicken of its
own accord, and then to reject it entirely, and not
trouble about its benzol content. He thought that
perhaps Mr. Lee was right about the naphthalene ques-
tion. One was apt to confuse one thing with another.
At the time that they got naphthalene trouble they also
had a lower yield, but that came from another cause.

Mr. Carr (Waleswood) said that on a direct recovery
plant they did not find the oil thicken. They eliminated
the tar before it entered the benzol scrubbers.

The President, referring again to the gas industry,
said he did not know that they were the pioneers of the
benzol industry. If they were, they had not benefited
much by the experience they ought to have gained.
Whilst the Coke Oven Managers were quite ready, as an

association, to afford the gas engineers the benefit of
their own experience, there was no reason why they
should push it down their throats. It was there when
they cared to ask for it. With regard to the circulating
oil, a great deal depended oh the working conditions of
their plants. If they were making crude benzol for
themselves, certain oil might be suitable which would
not be suitable if they were selling 65’s. His experience
with regard to shale oil quite bore out what Mr. Lee had
said. They had great trouble with water. With
anthracene oil washing, in contradiction to Mr. Thorpe,
his experience was most disastrous. He had taken so
much notice of what he had seen at Mr. Wilson’s plant,
and what he had heard him say, that he had gone in for
a rather big set of centrifugal pumps. He had found
gilled pipes, placed horizontally with vertical gills, to
work very satisfactorily indeed. With regard to chang-
ing the oil, the practice they adopted, and found very
satisfactory, was to keep adding a little fresh oil every
two or three days, so that' the oil never got above 10 or
12. If they started with a good oil, and finished up
with a bad, there must be a time when their efficiency
was impaired very considerably.

A vote of thanks was accorded to Mr. Wilson for his
paper, on the motion of Mr. Price, seconded by Mr.
Taylor.

THE STATE-PAID COLLIERY FIREMAN.

A lecture, under the title of “ The State-paid Fireman
—will he reduce accidents in mines ? ” was given before
the Platt Bridge (Wigan) branch of the Lancashire and
Cheshire Colliery Firemen’s Association on Saturday
week by Mr. Thomas Mason, colliery manager, of
Wigan, who said that the inventor of the proposition
for the State-paid fireman must have been ignorant of
the practical and economical life of our present-day
fireman. They were told by the promoters of the pro-
position that a fireman should be appointed, controlled
and paid by the State, so that he would be independent
of the owners, managers and miners alike in the interests
of safety. He maintained, however, that the State bad
already something to do with two of these requests.
The manager was strictly forbidden to appoint any
fireman unless he had complied with the law and had
passed satisfactorily the examination presented by State
officials, whilst under the new Regulations, 49 to 62,
firemen were controlled by statutory duties to the extent
of bringing the safety of mining to its maximum. He
should feel ashamed as a colliery official if bethought that
by being paid by the State he could reduce accidents.
He held the view that if any fireman thought he could
save limb and life by being State-paid, he ought to do it
now. In the speaker’s belief, firemen generally did
attempt to do it so far as their intelligence and foresight
could guide them. It was insulting and dangerous
patter to suggest that the fireman could reduce accidents
in mines by being State-paid, and it was equally
insulting to the manager, or the under-manager, to be
told that he impeded the fireman in his statutory
duties. Surely the leaders of the firemen were not
thinking that the owners did not desire to have their
pits free from accidents. If so, they could disabuse
their minds of such an idea, for the simple reason that
accidents did not pay. Any accident was so much loss
to the owner financially, and thereto e the owner
naturally expected all his officials to see as far as they
could to the interests of safety. Personally, the
lecturer felt certain that being State-paid would not
only be harmful, but would tend to increase rather than
decrease accidents in mines, because once outside the
direct touch of the manager and the under-manager
there would be a tendency towards slackness in super-
vision, and firemen would become dilatory in their
methods of action. They must rememl er they would
still be human and subject to human errors, and would
be liable to drift, through lack of incentive, more into
mechanical action instead of being the thoughtful
and prudent men they ought to be. It was much Letter
for them financially, and in the interests of safety, to be
paid as they now were. They should adopt State
control as defined in then* statutory duties, and carry
out those duties fearlessly in their supervision of the
miner at his work. By so doing they would assist their
manager *and under-manager to the fullest extent in the
interests of safety. He was sure it was much better to
keep the chain of management unbroken and working
in harmony than to take a link out and risk the chance
of disaster. Let the mining world see that they could,
by the application of thought, tact and judgment, serve
the interests of safety in mining, irrespective of whether
the paymaster happened to be private owner or State.
Then, he felt sure, they would have earned and would
receive the gratitude of both owners and miners.

Prospecting for Coal in France.—The French Minister of
Public Works has informed the President of the General
Council of Calvados that the Government has decided to ask
Parliament for the necessary credits to enable prospecting
for coal to be undertaken in that Department. The coed
basin of Littry (Calvados), to the east of Saint-Lo, has
already yielded a couple of million toms of coal in former
times; and more recently (in 1907) a German group carried
out borings at St. Jean de Daye, which were reported to have
encountered four seams of coal, each 5 to 6 ft. thick (two of
them workable) at a depth of 300 to 400 yds. Now, the
French State is to resume the work. The depth of the coal
measures has been estimated by M. Delafosse as 400 to
500 m. from the surface, provided the jurassic rocks are
underlain by lias and trias formations. It may be, how-
ever, that some considerable portion of the secondary rocks
which overlie the coal measures in the Pas-de-Calais have
been removed by erosion, the position of the northern coal
field and that of Normandy with relation to the cretaceous of
the Paris basin lending some support to the probability of
this being the case.