The Lexington intelligencer. [volume] (Lexington, Mo.) 1901-1949, 1904-01-30
cost DUST EXPLOSION.
Results Of Experiments Recently
Carried On in England.

Va apartments Recently
Carried On in England.
Experience proves that fine dust
IN soft coal mines is almost as
dangerous as gas. Though the ex.
piosions thus caused are not so
numerous and terrible, perhaps, as
those which result from hredamp,
the risk attendant upon the exist.
ence of dust is now beyond ques-
tion. Not only will it aggrayate
the violence of an explosion when
both gas and dust are involved,
but it will make trouble by itself
when there is little or no gas pres
ent. This fact has been estab-
iished recently by a set of expert.
.ments in England, undertaken
under the auspices of a govern
ment commission, by an inspector
named Eall. The tests were made
in such a way as not to hurt any
body, and, though not as exten-
sive and complete as could be
wished, we're conclusive. James
Ashworth, In "Mines and Miner
ais" summarizes a part of Mr..
Halls report:
he proved that when a gunpow-
der shot was fired in a pit so yards
deep and 2 feet in diameter and
ventilated by an air current of $50
cubic feet a minute-that % min,
utes after the coal dust had been
thrown into the pit and only the
dnest dust remained in suspen-
sion-that under these conditions
a very violent explosion might re-
cult and flame be forced out Of the
shaft to a height of 60 feet. The
photographs of the explosions, as
they appeared above the pit top,
showed that when only the fine
dus4 was in suspension the smoke
and dust were less dense and the
dame more intense, Experiments
were also made by firing shots in
che pit 80 to AS minutes after the
previous explosion without add
Ing any additional dust, and the
resultant explosion shot up is to
so feet above the pit top.
A record was kept showing the
state of the weather while the ex.
periments were in progress. Most
Of the tiuae the air was very dry.
still, on at least two days the hu.
nudity was high, the atmosphere
being almost completely saturat.
ed with moisture. On these occa.
sions the first one or two charges
OF gunpowder Of blasting powder
which were ignited would not set
on the dust, but the second or
third one would result in a violent
explosion. In all of these cases
the Ignition of the first blast was
preceded by the intentional add
tlon of dust to the air in the shaft
Anasmuch as each discharge would
drive a little of the dust out nm.
burned, the amount in suspension
was less when the third explosion
occurred than at first. Hence
damp air, while it discourages ex
pioslon, does not entirely prevent
il. Mr.. Ashworth adds:
In reference to these expert.
snents mr.. Hall remarks that
mines which are naturally of a
dry and dusty character cannot
be ~artiicially damped so as ia
render gunpOwder safe, and it is
deserving OF consideration and
experiment to test whether a coal
dust explosion would be STONED
In It's course by a certain length Of
roadway being constantly kept in
q wet condition, Personally,
thlnis such a plan would not prove {
effective, in consequence of what {
may be termed the pioneering
cloud Of dust which precedes the |
Games"
Apparently, the point is not vet {
fully cleared up; but if watering a |
mine will not check dust expIo. !
then better ventilation NAV
be deemed necessary.