Illuminating Gas and other Gaseous Fluids.
Year: 1889

page_text: Illuminating Gas and other Gaseous Fluids.
We, THOMAS ARTHUR GREENE and CHARLES MAYNARD WALKER, both of
155 Cannon Street in the City of London, Gas Engineers, do hereby declare the
nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
Our invention relates to the construction of an extremely sensitive liquid governor
for regulating the supply of illuminating gas and other gaseous fluids, so constructed
as to work with the smallest possible amount of friction, and which, being of very
simple construction, is not liable to get out of order and is very reliable in its action.
The invention consists mainly in the arrangement, in a chamber containing a suitable
liquid such as mercury, of an annular float surrounding a central outlet orifice for the
gas, projecting up from the bottom through the liquid, which float is connected by a
bridge-piece to a central stem the lower end of which passes loosely into the orifice of
the gas outlet, while the upper end extends up to the underside of a flat valve that
closes the inlet for gas into the top of the chamber. The valve has a central coned
recess on its underside, against the apex of which bears the pointed end of the stem,
so that the valve acts as the upper guide for the stem without being jointed thereto,
thus avoiding all friction. The valve is pivotted at one side to the casing, by
preference in the manner to be presently described, so as to produce the least possible
friction. The float chamber being made to communicate at bottom with a second
chamber to which consequently the liquid also has access, the action of the governor is
as follows:-
The two chambers are charged with liquid to such a height that when gas enters
the inlet opening at the desired pressure, the float will hold open the valve to a certain
extent, but when the gas pressure increases, such pressure will depress the level of the
liquid in the float chamber to an increased extent, forcing a portion of the liquid into
the second chamber where the level will consequently rise. By such depression of the
liquid the float will consequently descend and will allow the flap valve to close more
or less by gravity, thereby restricting the flow of the gas and regulating its pressure.

page_text: .
This action will be assisted by the increased downward pressure of the gas directly.
upon the upper surface of the valve and also by the downward pressure upon the
upper surface of the float, tending to immerse it to a greater extent into the liquid.
On the pressure decreasing again the head of liquid in the second chamber will cause
that in the float chamber to rise again and in raising the float, to open the valve again
to the normal degree.
By the above described means an exceedingly sensitive action of the governor is
obtained, which is principally owing to the fact that the pressure of the inflowing gas
is in the same direction as that of gravity acting on the valve, and to the absence,
practically speaking, of friction in the moving parts.
The accompanying drawing shews at Fig. 1 a vertical section of a governor constructed
according to our above described invention. Fig. 2 shews a plan of the same; A is
the outer casing of the governor closed at top by a screw cap B to which is attached
a cylindrical extension C passing down so as to leave a small "opening between its
lower end and the sides of the casing A, thus dividing the space of the latter into a
central or float chamber which communicates with. the gas supply, and an annular
outer chamber which communicates with the atmosphere.
To the top of the cap B is fixed a nozzle E by which the governor is connected to
the gas supply pipe, and the central chamber communicates with this through a
passage II which is closed at top by a flap-valve D pivotted at I. Into the lower end
of the casing A is fitted an outflow nozzle F which projects up a certain distance into
the float chamber, and the lower end of .which is -fixed to the outflow pipe. The
casing A is charged with suitable liquid, such as mercury, which is introduced through
an opening J on top, communicating with the outer chamber C of the governor and
fitted with a plug so as to leave a restricted communication between the outer
chamber and the atmosphere, the central chamber being cut off from such communi-
cation by the liquid seal at bottom.
In the central chamber is placed an annular float K of any suitable material
surrounding the nozzle F and having a central stem L connected thereto by a bridge-
piece, the lower end of which stem passes loosely into the opening of the nozzle F
which thus acts as a guide thereto, while the upper pointed end butts against the apex
of a conical recess on the underside of the valve D, which thus acts as the upper guide
to the stem. The quantity of liquid in the casing A is so adjusted that. the float will
hold the valve D open to a certain extent by means of its stem when the level of the
liquid in the central chamber is slightly depressed by the normal pressure of the gas
supply. On any increase of the pressure of the entering gas beyond the normal, this
will depress the liquid level in the central chamber to a greater extent, causing the
float to sink, thereby allowing the valve D to close to a corresponding extent, and
consequently restricting the inflow of gas and diminishing its pressure, which action
will be aided by the increased direct downward pressure of the gas upon the valve,
and upon the float as before stated.
In order to insure perfect freedom of motion to the valve by obviating friction as
much as possible in its joint, we by preference construct the post to which the valve is
pivotted, with two side centres; the valve is fitted with arms D' having pointed ends
which spring into the centres of the post, being merely in contact therewith at the
extreme points, as shewn more clearly at Fig. 2. Thus the only frictional contact
between the valve and the post is that between the points of the arms and the
centres.
The adjustment of the governor to afford any desired pressure of the issuing gas
may be effected by raising or lowering the liquid level either by introducing a greater
or less quantity of liquid or by more or less protruding a displacing plunger into the
liquid, but by preference we effect it by more or less restricting by any known means
the outflow of the gas from the governor, and we prefer to employ for this purpose a
screw plug G of well known arrangement such as is described in Thorp's Specification
No. 2137 of 1888.
We are aware that it has already been proposed to employ a float for regulating.a
gas supply valve, by causing the gas pressure to raise or lower the level of a liquid

page_text: contained in two chambers, communicating with each other one of which contains the
said float, such an arrangement being described in Clark's Specification No. 1818 of
1881, and we do not therefore claim such an arrangement generally.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In a governor for regulating the supply of gaseous fluids, the use of an annular
float situated in a liquid that is subject to the pressure of the inflowing gas, which
float has a central rising stem that butts against the underside of an inlet flap valve so
as to hold it in an open position without being connected thereto, so that any increase
of pressure of the inflowing gas in depressing the level of the liquid, causes the float
to descend, and the valve to close more or less by gravity substantially as herein
described.
2. In a governor for regulating the supply of gaseous fluids, the use of an annular
float K, surrounding a gas outlet nozzle F and having a central stem L connected,
thereto by a bridge-piece, the lower end of the stem being guided in the orifice of the
nozzle F while the upper pointed end butts against the apex of a coned recess in the
underside of an inlet flap-valve D, forming a self-centering guide way, substantially
as herein described with reference to the accompanying drawing.
3. In governors for regulating the supply of gaseous fluids, the general arrangement
and combination of parts substantially as herein described with reference to the
accompanying drawings.
D
101 1
CT1
1000