Improvements connected with Pipes and Conduits for Localizing the Effect of Explosions therein, and so Minimising Damage. therefrom.
Year: 1897

page_text: Date of Application, 16th Dec., 1897
Complete Specification Left, 27th July, 1898-Accepted, 1st Oct., 1898
PROVISIONAL SPECIFICATION.
Improvements connected with Pipes and Conduits for Localizing
the Effect of Explosions therein, and so Minimising Damage.
therefrom.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicated to me from abroad by Edouard Fouché, representing La Com-
pagnie Francaise de l'Acetylene discous, of 28, Rue St. Lazare, Paris, in the
Republic of France) to be as follows:-
This invention has for its object to provide means for ensuring safety in pipes
and conduits enclosing explosive gases such for example as acetylene gas by
preventing any explosion that may occur at any point, from spreading to any
great extent in the pipes or conduits.
According to this invention there is inserted at intervals in the pipe or conduit
an obstacle which localizes the explosion and which is brought into play by the
explosion itself.
However rapidly an explosion may spread such spreading does not occur
instantaneously. The considerable pressure developed at the point where the
explosion occurs is according to this invention utilized to operate a device which
closes the conduit or pipe at a point but little in advance of the point of explosion,
so that the explosive effect is thereby stopped.
The device will fulfil the required object, provided that the time necessary for
the mechanism actuated at the point of the explosion will close the pipe or conduit.
at the point in advance in less time than that required for the effect of the explosion.
to traverse the distance between these two points. In order that this result may
be attained, care is taken that the points are sufficiently far apart from one
another in the course of the pipe or conduit, whilst their distance in a straight
line is as small as possible which may be effected by giving the passage through
the pipe or conduit a bend between the said two points.
An apparatus suitable for the purposes of this invention consists of a junction
piece in line with and connected to the pipe or conduit. A tube open at its
bottom and containing a porous substance is secured in the said junction piece.
A second tube closed at one end, fits round the first mentioned tube like a cap,
the cylindrical wall of this second tube lying between the first tube and the
inner wall of the junction piece. These various pieces leave but a small free
space between them.
A perforated piece is used as a support for the second tube.
The gas can pass through the porous substance and through the small spaces
existing between the tubes and finally through the perforated supporting piece.
When an explosion occurs, the pressure resulting therefrom first causes the
sides of the aforesaid tube in the junction piece to be forced against the sides of
the said junction piece so that when the explosive effect ultimately arrives at the
intermediate space between the said tubes and between the outer tube and the
junction piece it finds its way blocked and is thus stopped.

page_text: The object of the porous substance is to create, at the moment of the explosion,
a strong resistance to the passage of the gas, the effect of which is to maintain for
a certain interval of time an increased pressure in the first portion of the inner
tube so that the forcing of the tubes against the sides of the junction piece is
ensured and maintained.
The porous substance may be of any suitable kind; or any suitable material
may be used such as sand, tightly packed between two pieces of wire-gauze.
The invention is not limited to the precise device described for example it may
consist of a cylinder provided with external screw threads and introduced and
held in the junction piece with the inner wall of which it comes into contact only
at the edges of the screw threads. The helical space between the screw threads
forms a long passage for the gas. The centre of this screwed cylinder is hollowed
out and contains at its lower part an accurately fitting and hollow piston.
Opposite this piston and a short distance from it is a filling piece with a per-
foration in it around which is a tapered groove into which the thin bottom edge
of the piston can enter so as to become wedged therein.
In order to ensure an absolutely reliable closing of the perforation by the piston,
the said groove may be filled with any suitable plastic substance, into which the
edge of the piston enters.
Under normal conditions the gas passes freely through the helical passage
between the screw threaded cylinder and the sides of the junction piece and
between the end of the said cylinder and the perforated filling piece and thence
through the hole in the said filling piece. When an explosion occurs, and before
its effect can pass through the helical space, it forces forward the piston so that
it becomes wedged in the groove around the hole in the filling piece and thus
closes it and therefore the conduit.
1 ..
1
100%
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements connected with Pipes and Conduits for Localizing
the Effect of Explosions therein, and so Minimising Damage
'therefrom.
1 I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicated to me from abroad by Edouard Fouche, representing La Com-
pagnie Francaise de l'Acetylene dissous, of 28, Rue St. Lazare, Paris, in the
Republic of France) and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
This invention has for its object to provide means for ensuring safety in pipes
and conduits enclosing explosive gases such for example as acetylene gas by
preventing any explosion that may occur at any point, from spreading to any
great extent in the pipes or conduits.
According to this invention there is inserted, at intervals in the pipe or conduit
an obstacle such as an elastic diaphragm or other device which localizes the
explosion and which is brought into play by the explosion itself.
Referring to the accompanying drawings,
Figure is a diagrammatic view, of a pipe in which an explosion is supposed
to occur

page_text: Figure 2 illustrates in longitudinal section a device constructed according to
this invention for stopping or localizing the explosion.
Figure 3 shews in longitudinal section a modified arrangement of the same.
The invention is not restricted to the precise details shewn in the drawings.
However rapidly an explosion may spread such spreading does not occur
instantaneously, and taking two points A and B of a conduit (Figure 1) for
illustration, an explosion which we will suppose occurs in the direction of the
arrow F, at the point A must take place at this point a certain interval of time
before it reaches B. The considerable pressure developed at the point A where
the explosion occurs is according to this invention utilized to operate a device
which closes the conduit or pipe at the point B, but little in advance of the point
of explosion so that the explosive effect is thereby stopped.
The device will fulfil the required object, provided that the time necessary for
the mechanism, actuated at the point of the explosion A, for closing the pipe or
conduit at the point in advance B, be less than that required for the effect of
the explosion to traverse the distance between these two points. In order that
this result may be attained, care is taken that the points A and B are sufficiently
far apart from one another in the course of the pipe or conduit, whilst their dis-
tance in a straight line is as small as possible which may be effected by giving
the passage through the pipe or conduit a bend between the said two points.
An apparatus suitable for the purposes of this invention is shewn in Figure 2.
It consists of a junction piece M M in line with and connected to the pipe or
conduit 0 0¹. A tube A provided with a flange B constituting a diaphragm is
held between the two flanges N M¹. The said tube is open at its bottom and con-
tains a porous substance P.
A second tube C, closed at one end, fits round the first mentioned tube A like
a cap; the cylindrical wall of this second tube C lying between the said tube A
and the inner wall E of the junction piece. These various pieces leave but a
small free space between them.
A piece I perforated with holes e is used as a support for the second tube C.
The gas can pass through the porous substance 1', and through the small
spaces existing between the tubes and finally through the perforated supporting
piece.
When an explosion occurs in the direction indicated by the arrow F, the
pressure resulting therefrom first causes the sides of the aforesaid tubes in the
junction piece to be forced against the sides E of the said junction piece so that
when the explosive effect ultimately arrives at the intermediate space between the
said tubes A and C and the tube C and the side E of the junction piece it finds
its way blocked and is thus stopped.
.
The object of the porous substance P is to create, at the moment of the explo-
sion, a strong resistance to the passage of the gas, the effect of which is to main-
tain for a certain interval of time an increased pressure in the first portion of the
inner tube so that the forcing of the tubes against the sides of the junction piece
is ensured and maintained.
The porous substance may be of any suitable kind, or any suitable material
may be used, such as sand, tightly packed between two pieces of wire-gauze.
The invention is not limited to the precise device just described, for example,
a modified device as shewn in Figure 3 may be employed.
In this arrangement a cylinder A is employed provided with external screw
threads and introduced and held in the junction piece E (which is provided with
flanges M) with the inner wall of which it comes into contact only at the edges of
the screw threads. The helical space between the screw threads forms a long
passage for the gas. The centre of this screwed cylinder A is hollowed out and
contains at its lower part an accurately fitting and hollow piston P.
Opposite this piston P and a short distance from it is a filling piece B with a
plug piece with a perforation H in it around which is a tapered groove V into

page_text: which the thin bottom edge of the piston P can enter so as to become wedged
therein.
In order to ensure an absolutely reliable closing of the perforation H by the
piston P, the said groove V may be filled with any suitable plastic substance,
into which the edge of the piston enters.
Under normal conditions the gas passes freely through the helical passage
between the screw thread cylinder and the sides of the junction piece and between
the end of the said cylinder and the perforated filling piece and thence through
the hole in the said plug piece. When an explosion occurs in the direction
indicated by the arrow F, and before its effect can pass through the helical space,
it forces forward the piston P, so that it becomes wedged in the groove P, and
thus closes it and therefore the conduit H.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. Improved means for ensuring safety in pipes and conduits, enclosing explo-
sive gases, by interposing or inserting in such pipes or conduits an obstacle or
stopping device which utilizes the pressure produced by the explosion, for closing
the whole passage in the pipe or conduit in front of the said explosion; the
explosive effect after having operated the closing mechanism being compelled to
traverse, a circuitous or helical passage, in order to reach the portion of the pipe
or conduit now stopped; this stoppage being obtained either by the deformation
of an elasti, body or diaphragm, or by the action of a stopping device or plug of
any kind, substantially as described.
2. For localizing the effect of explosions in pipes and conduits enclosing explo-
sive gases, an obstacle consisting of a retarding device formed of a porous or
pulverulent substance placed in the passage of the gases in combination with a
stopping device formed by an elastic body or bodies or diaphragm substantially
as herein before described with reference to Figure 2.
3. For localizing the effect of explosions in pipes or conduits the construction
of a retarding and stopping device formed by the combination of a cylinder or
the like with an external elongated and helical passage for the gases, and of
a movable plug to be operated by the explosion to close the pipe or conduit sub-
stantially as herein described with reference to Figure 3.
Date : 971 of 1.. 1000
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.