226

THE COLLIERY GUARDIAN.

February 2, 1917.

calorific power would be decreased, but with a fairly
good coal they could rely on that figure. Of course, if
they were going to use slimes, they wanted to get rid
of the water. The slimes must be dried, but the
material was there. He had had sent tb him some of
the slimes from the Staffordshire district that were
thrown away by the acre, and, properly used, they con-
tained over 8,000 British thermal units.

The President asked what was the comparative value
of briquettes made from a good coal 'with 12 per cent, of
ash and similar steam raising coal.

Mr. Yeadon said, they might take it, generally, that
if. they kept their briquettes under 12 per cent, of ash,
they would get the' same price, or more, for them, than
they would for the best house coal.

The President : What about the steam raising?

Mr. Yeadon : Steam raising the same. They would
find, if they looked at the lists in South Wales, that the
patent fuel, or briquettes, were slightly higher than the
best steam coal and the best house coal; so it was simply
a question of keeping down the ash and getting a fair
good quality if one wanted to sell them to the market.
If they wanted to use them for themselves, they could
use anything up to 30 per cent, of ash.

The Rectification of Benzol.

Mr. W. Newton Drew then read his paper on “ The
Rectification of Benzol.” (See Colliery Guardian,
January 26, p. 179.)

Discussion.

The President said they were very much indebted to
Mir. Drew, who was a busy man, for preparing the paper.
With regard to the use of benzol as motor spirit, there
had been an attempt made—although he agreed with
Mr. Drew that it was a very half-hearted attempt—to
get it put commercially on the market. He himself was
one of the first to use benzol in cars, and stuck to it for
a considerable time, but had to give it up because of its
objectionable smell. Since then, they had succeeded in
washing it to such an extent that they got a very good
spirit indeed. A great many people would be'only too
pleased if they could get benzol to use now, instead of
the stuff which was sold to them at a high price and
called petrol. He proposed a hearty vote of thanks to
Mr. Drew for his valuable paper.

Mr. G. Blake Walker seconded, and the resolution
was carried.

Mr. G. L. Moss said Mr. Drew had alluded to the
changed conditions in the industry resulting from the
war. In the old days, benzol rectification was carried
out to a great extent by tar distillers, and the fractiona-
tion of the products was very crude indeed. It was the
custom ■ to .simply distil in any old thing that would do
as a still, and use any sort of a column. Fractionation
in those days was very little understood. The majority
of people were content with a simple tube, usually of
wrought iron, filled in some cases with bits of broken
brick, and in others with perforated plates, and they
usually dispensed with analysers. He was speaking of
people who just made ordinary 90’s benzol, and did not
manufacture pure, for which then there was a fair
demand. A considerable quantity was exported to the
Continent, principally to France. In those days there
were, regulations under which benzol could not be
imported into France as benzol, and it was imported as
a tar oil, or under same ambiguous description of that
kind. It was made into pure in this country, and
coloured brown with pitch; then at the other end it was
simply blown over rapidly, and they got the pure stuff
without any trouble. Since the war started, the
Government regulations had been very strict, and atten-
tion had had to be given to fractionation and the frac-
tionating details, and to cutting out the toluol, which
Mr. Drew had rightly spoken of as being very valuable.
The fractionation of these compounds of the homologous
series was comparatively simple, but required some
attention, and also some intelligent design of plant to
get the best results with the least possible trouble.
There were several types of column employed, but
recently, and, in his opinion, rightly, the type that Mr.
Drew' had described had become the , most prominent.
This was the cast iron column, built up in sections,
each section having a number of hoods in which the
vapour of the benzol had io bubble, through a definite
seal of liquid descending the column. The other type
was simply of wrought iron circular section, built up of
rather longer sections, with numerous trays inside per-
forated, and with return seals. The difficulty in that
case was that the action was not so positive. The frac-
tionation was good, certainly, but the holes were liable
to block up with scale and dirt. . Before leaving the
question of the conditions now as compared with before
the war, it might be interesting to'remember that, when
. benzol was first employed as motor spirit, the market
for toluol was practically nothing at all. Toluol fell to
a, hopeless,price, and consequently the distillers used to
mix their toluol in with the benzol. So far, however,
from being an adulterant, this was of great benefit, in
that it increased the calorific power of the motor spirit,
and, in the winter time, prevented freezing. . Benzol
froze at about 6degs. Cent., and considerable trouble
was experienced in the early days, when makers
endeavoured to make their benzol very good, because in
the winter time, owing to the rapid motion through the
air, the tanks often got frozen. The mixing of toluol
with the spirit obviated this, and there was no doubt
that, when the demand for toluol for explosives fell, its
admixture with benzol would be beneficial to motor
users. He agreed with Mr.-Drew that there should be
some better organisation for the distribution of motor
spirit after the war. There was no doubt that we should
be heavily in debt, and that every effort that could be
made to keep down the imports, and therefore keep up
the -rate of exchange, would .be necessary. If we could
produce, as he thought we could, 60,000,000 gals. of
motor spirit per annum, and rightly organise our

resources and distribution, he thought we could effec-
tively knock out the petrol combines, or at least very
much reducb their prices. He was afraid he could not
comment very much on Mr. Drew’s admirable paper,
because the author had covered the subject so well, and
in the. main he (the speaker) agreed entirely with his
method of working the plant, with regard to the running
of the once-run fractions. In certain quarters this met
with opposition, but he thought that in well-informed
quarters there w’as very little doubt that this was the
better method of working—that was, to distil the crude
first and roughly divide it, and afterwards wash the pro-
ducts separately. They got a better fractionation that
way, and it was easier worked. It meant a little more
complication, perhaps, but it all tended to economy and
efficiency in working.'As to the “topping up” referred to
by Mr. Drew, he himself had found it advantageous, not
only as ensuring full charges in the still, and a.minimum
of starting and stopping, changing over, and so forth,
but it also had a very beneficial effect on the fractiona-
tion, inasmuch as the cutting and changing points were
considerably reduced. Moreover, the fractionation of a
still depended very largely upon the amount in the still
of the product they were working for. If they had a
charge of once-run benzol in a still, they would have a
certain amount of toluol, say, 20 per cent, present,'and
they accumulated that toluol, and got a much better
product when they started working for the toluol, by
accumulating it, than they would if they worked it off
straight away after the benzol, because they had a bigger
hulk to deal with, the percentage of intermediate pro-
ducts of toluol was much reduced, and the number of
changing over times was also reduced. He should like
to ask Mr. Drew if he had at any time found corrosion
taking place in the analyser tubes, and whether he liked
the idea of superposing the analyser on the column, or
having it as a separate piece of apparatus. The advan-
tage in having it separate was that the column could be
readily dismantled without handling any extra weight;
also, the analyser being full of water, and being a
rather heavy piece of apparatus, imposed more strain
on the centre ring of the still, and thus the still shell

The Oliver Automatic Safety Skip.

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itself had to be designed rather strongly. With regard
to the patent referred to by Mr. Drew for the direct-
washing of benzol, he thought there was a little mis-
apprehension. Mr. Drew said: “In this new process
the vapours from the crude benzol still before condensa-
tion,” and so forth. It was not from the crude still,
but from a rectifying still, taking the crude benzol after
separating from water at the crude plant in the ordinary
way. He regretted that he could not tell the meeting
anything about the apparatus, as his experiments were
not completed. He had great hopes that it would be a
success, both practically and economically. The advan-
tages were obvious,- and he should like to hear what
opinion Mr. Drew had formed of it. The difficulties,
too, were pretty patent to anyone that had anything to
do with the industry. He should like to know Mr.
Drew’s opinion on continuous distillation, both as
regarded efficiency and economy. It was a matter that
was receiving attention now, and had done so in the
past, but it had not been made a startling success so far.

Difficulties of Continuous Process.

Mr. Drew, in acknowledging the vote of thanks, and
replying to the discussion, regretted the absence of Prof.
O’Shea, an authority on the subject. He saw many
difficulties in Mr. Moss’s process, ingenious as it was,
but when he remembered that it was in that city, some
eight years ago, that they first heard the outline of the
direct recovery of sulphate, and scoffed at the idea, he
was very diffident about saying that anything was
impracticable, particularly a system like that of Mr.

Moss’s, which was capable of careful study on a fairly
small scale. The difficulties which he should foresee
were that, at-a temperature at which the vapours would
remain as gas, the sulphuric acid, would be very hot,
and he should imagine that,, unless the bubbles were
almost infinitely small, the outward part of the bubble,
in passing through the hot acid, would be sulphonated
and destroyed, whereas the inside would not be washed.
But it really was a matter of experiment, 'and he sin-
cerely hoped that Mr. Moss would-be successful, as, if
so, his process would cut out a great deal of cumbrous
plant, and save a great deal of money. As to con-
tinuous distillation, he had made attempts at it, not
with benzol, but with other things, and it had always
seemed to him that the game was not worth the candle.
Still, that was a thing that should certainly be studied
in the future, and might prove a great economy. He
had not found any corrosion in the tubes of the dephleg-
mator. He agreed, with Mr. Moss that it was better to
have the dephlegmator separate. "With regard to the
president’s remarks on benzol, he had been informed
that their petrol friends had made a collection cf corroded
engine parts, the damage to which had been caused by
the use of benzol; so that, whatever combination they
made, they would probably have a fight. The advan-
tages of benzol were several, and there were certain dis-
advantages. He considered it was a very much better
fuel, and he hoped they would all push their own pro-
duction, as far as they possibly could, in the future.

The President remarked that he had a car which had
done close on 200,000 miles, nearly all on benzol.

THE OLIVER AUTOMATIC SAFETY
SKIP.

Mr. Frank Oliver, M.E., a member of the Canadian
Mining Institute, is the designer of a safety automatic
skip for use. in vertical shafts, which are now being
installed at the McIntyre-Porcupine. Mine, South
Porcupine.

The advantages claimed for this skip are:—(1) The
skip in. motion is absolutely locked, so that it cannot
tip, however loaded, while in motion until it reaches
the tipple; (2) the cost of construction on skips of one
ton capacity and over is much less than other designs;
(3) low weight of skip compared with weight of its
capacity.	<

The yoke for. this skip, shown in the accompanying
figure, is made of J in. X 6 in. soft steel, which is
carried round the bottom of the skip, being riveted
only to a 1 in. x 6 in. soft steel head piece, between
angle irons.

The slippers, which stride the guides, are riveted to
the sides oi the yoke through IT plates holding slipper
side plates, the side plates being made of % in. spring
steel. The depth is governed by the size of guides used.

The roller brackets, which act as locks on the sides
of guides, straddle the yoke and engage with the
guide by means of a roller, the bracket being made of
soft steel drawn or forged down from J in. X 6 in. to
2 in., which is the diameter of the base of the axle,
which is set at right angles and turned down to lj|in.
The roller is made of cast steel 6 in. in diameter, and
the width of guide. It is bored out to Iff in. to fit the
axle of the roller bracket.

The body of the skip is made, as most well-built skips
are, of Jin. plate for sides and T5^ in. bottom plate, with
1 in. wood false bottom, with J in. plate above the false
bottom.	.	,

The axle on the bottom of the skip is made also of
mild steel, out of 2 in. square, turned down to 1 in.