Idaho County free press. [volume] (Grangeville, Idaho Territory) 1886-current, 1916-08-03
DEPARTMENT OF AGRICULTURE
SUGGESTS EXPLOSION SAFEGUARDS

duced i'll number of ways by the oper.
alton of the machine during the thresh-
ing process and under certain condi-
tions will readily ignite the dustladen
atmosphere within the thresher. 1t is
generally agreed that before this can
take place the dust must be fine and
dry and in a state of suspension, but
the exact conditions necessary to bring
about an explosion have not been
definitely determined. This uncer.
tainty, it is said, is strong argument
for equipping all threshers with the
| preventive devices already named
| The best method, the Investigations
indicate, for carrying off any static
electricity that may be produced is to
connect wires from all moving parts ON
the machine to one wire and to ground
that wire. This is the method that has
been adopted in the system recommends
ed by the department specialists. In this
system the common wire or conductor is
grounded through a rod which should
be driven at least 3 feet into the ground,
which should be kept moistened. There
are connections to this conductor from
the shaft OF the cylinder, from shakers,
from the entire sieve, and from the
metal casing of the stacker fan. These
parts are the ones on which static elec-
| tricity appears most likely to be gene
rated The common lead and its main
branches are of No. IA bare copper wire.
Connections should be flexible insulated
wire coied a sufficient number of times
to permit full flexibility. The wire
should be attached to the framework Of
wooden machines by staples, which
should be of the insulated type, or else
there should be a cushion of rubber or
other material between the staple and
the wire. Otherwise the wire is likely
to snap and break the circuit.
The installation of the suction fan is
desirable because, before explosion can
occur, there must be favorable mix.
ture of dust and air The purpose OF
the fan, therefore is to remove the dust
from the vicinity of the cylinder. The
arrangement recommended by the inves-
tigators is to attach a suction fan to
the top of the separator. This fan
exhausts from above the cylinder and
also from beneath the fan.
While it is pointed out that there Is
no way of absolutely demonstrating that
either the grounding of the machine or
the suction fan actually prevents ex'
plosions, the fact remains that no such
occurrences have taken place, as far as
properly equipped in this way. On the
other hand, explosions are constantly
occurring in the other machines operat-
ed without them but otherwise under
identical conditions.
These devices, however, do not re-
move all danger from fire, for in addi-
tion to electric sparks foreign materials
which find entrance into the separator
may start fires, and for this reason the
automatic fire extinguisher is regarded
as desirable additional protection.
This device consists of tank mounted
on top Of the separator. This tank Is
filled with water containing soda, and in
addition there is bottle within 1t
. filled with sulphuric acid. A wire line,
0 in which are mounted number or
, fuses, connects the tank with the sepa-
s rator. If sufficient heat is developed
= within the separator, one or more II
7 these fuses will melt. This breaks the
wire line and releases a trigger mechan-
! ism and causes hammer within the
d tank to strike and break a bottle of sui
n phuric acid. The discharge of the sui
!, phuric acid forms carbon dioxide. This
d generates sufficient pressure to force
the water through the discharge pipe
n and the discharge noZzles to all the
% lereyices of the separator. The locations
e of the fuses will vary with each type OF
n machine. They must be such, however
q that the fuses are sure to be reachec
d either by the flame or the heat. On thu
. other hand, they must be so placed thai
" the wire connecting them will not bt
n broken by the straw or by the moving
/ parts of the separator. The location oi
the nozzles also depends upon the type
It of machine. Further details in regard
II to the construction of this device anc
IS of the two others will be furnished witt
e blue prints upon application to tns
$, Office of Public Roads and Rural Engl
IL neering.
y In recent years the number OF ex
n plosions and fires in threshing machines
1t appears to have been increasing
n to such an extent that tn'
+. situation is now serious in many sec
70 tions of the country. Definite reports
of 166 such accidents were received b.
E. the field workers of the department ant
1t investigated 1t is probable, however
e. that many more explosions occurred OF
'e which no reports were made. Snch &C
E. cidents have been known to cause seri
Gus injuries to workmen and in addl
ID tion are responsible for much destruc
s. ton of property and for Practlcalt.
1t prohibitive insurance rates. For tnes'
x reasons it is believed that the measures
10 outlined for their prevention deserve
he the careful study of all concerned wlti
a grain threshing.
|