FLUID FLOW CONTROL VALVE

REGULATEUR DE DEBIT DE FLUIDE

English Abstract

ABSTRACT OF DISCLOSURE
A valve for the automatic control of the
supply of a fluid to a system, the valve comprising
two chambers one of which is in communication with
the fluid supply via a trickle valve, and with the
system, and the other of which, being open to atmosphere,
is defined by a compressible hollow member disposed
Within the first chamber, and whose internal volume
is determined by the difference between the pressures
in the two chambers, the compressible hollow member
having an aperture therein formed as a seating for a
valve member disposed in the first chamber such that
when the valve member is unseated the two chambers
are connected, the position of the valve member being
adjustable by means outside said first chamber and
operative according to some condition in the system to
which the fluid is supplied.
- 1 -

Claims

m e embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows :
1. A valve for controlling the pressure of a
fluid supplied to a system, the valve comprising two chambers
one of which is in communication with the fluid supply
and with the system and the other of which has a port
through which fluid therein can escape, said other chamber
being defined by a compressible hollow member disposed
within said first chamber and whose internal volume is
determined by the difference between the pressures in the
two chambers, a surface of said hollow member being
formed as a seating for a valve member disposed in said
first chamber, such that when the valve member is unseated
said two chambers are in communication one with the other,
said valve member being connected to a valve stem which
passes through the interior of said other chamber and
outwardly thereof to abut movable means for adjusting
the position of said valve member and thus the pressure
at which the latter becomes unseated to release fluid
from said first to said second chamber.

2. A valve according to claim 1, wherein said
hollow member comprises flexible bellows having said
valve seating at one end thereof.
3. A valve according to claim 2, wherein said
valve seating is formed as an aperture in the end wall
of said flexible bellows, the valve member having a
portion which seats in said aperture.
4. A valve according to claim 1, comprising a
valve body serving to define said first chamber inter-
nally, said compressible hollow member being attached
in sealing engagement to a removable plug closing said
valve body.
5. A valve according to claim 4, wherein said
valve body is adjustable relative to said valve member.
6. A valve according to claim 1, wherein said
first chamber has a single port which communicates
with a duct carrying said fluid from said fluid supply
to said system.
7. A valve according to claim 1, wherein said
other chamber is connected permanently to atmosphere.
- 8 -

8. A valve according to claim 1, wherein said
first chamber communicates with said fluid supply via
a trickle valve.
9. A valve according to claim 1, wherein said
compressible hollow member is normally urged into an
expanded condition by means of a resilient member
disposed within said hollow member.
10. A valve according to claim 4, wherein said
valve body is adjustable by means of a pair of
internally threaded collars mounted on a threaded
outer surface of the valve body above and below a
fixed support member respectively, whereby the valve
body may be adjusted to a desired position and locked
therein.
- 9 -

Description

1l)59~03
This invention relates to a valve for controlling
the pressure of a fluid supplied to a system~ and ha~ for
its object the provision of such a valve through which
the rate of flow of the fluid is controlled both by the
pressures at the inlet and outlet sides of the valves and
by some other condition in the system to which the fluid
is being supplied. ~xamples of such a condition are given
below. -`
A~ an example of the application of such a valve,
it may be used to control the supply of air to a coal
washing installation in which washing water is agitated
by the air supplied. In this case the other condition
in the system to which the fluid i8 being supplied is the
amplitude of pulsation of the water in the washing installa-
tion.
Another example of the application of the valve
is for regulating the supply of air to apparatus controlling
the mixing of two liquids or solids. In this case the
other condition in the system to which the fluid i~ being
supplied i8 the variation in the supply of one of the
constituents to be mixed.
According to the present invention a valve for
controlling the pressure of a fluid supplied to a ~ystem,
the valvo comprising two chambers one of which is in
communication with the fluid ~upply and with the system
and the other of which has a port through which fluid
therein can escape, said other chamber being defined by a
- 2 -
':
A
- . . - , .. . , . .~ . . ,
,. . . ~ . . ,.. . ,. . ~,
.. ...

1059403
compressible hollow member disposed within said first
chamber and whose internal volume i8 determined by the :
difference between the pressures in the two chambers,
a surface of said hollow member being formed as a seating ^
for a valve member disposed in said first chamber, such
that when the valve member is unseated said two chambers
are in communication one with the other, said valve
member being connected to a valve stem which passes through
the interior of sa~d other chamber and outwardly thereof
to abut m~vable means for ad~ustingthe position of said
valve member and thu~ the pressure at which the latter
becomes unseated to release fluid from said first to
said second chamber.
As an example of the invention, a valve for
automatically controlling the supply of air to a coal- --
washing installation will now be described in greater
detail with reference to the accompanying drawing which
shows the valve in sectional elevation.
In the embodiment shown in the drawing the
fir~t chamber is defined by a hollow casing 10 vhich
via a port 11 communicates with the fluid supply via
a pipe 12 and trickle valve 13, and with the system
to which the fluid is to be supplied, via a pipe 14.
A plug 16 closes the ca~ing 10. The second chamber
is formed by flexible bellows 17 sealed to the plug
- 3 -
, ~ , . .

iO59403
16 at 18, and capable of compression within the
casin~s 10. A port 19 in the plug 16 permits free
movement of air to and from the bellows 17.
The upper rlat surface 20 Or the bellows
17 has a central aperture therein which forms a
seat for a valve member 21 which is formed in one
piece with a spindle 22 which passes downwardly through
the bellows 17 and plug 16. The lower end Or the
spindle 22 as viewed in the drawing may be connected
to a float in the bed o~ the coal-washing apparatus,
or, alternatively, a~ shown, can be disposed against
a cam 23 which moves according to a condition prevailinl 5
in the washing apparatus.
~e casing 10 is adjustable in position
by means of a pair Or internally threaded collars 24
mounted on the threaded outer surrace Or the casing
above and below a Pixed support member 25, so
that the valve can be raised and lowered and locked
relative thereto.
In operation, air is ~upplied to the interior
of the casing 10 via pipe 12 and trickle valve 13. The
port 19 is ooen to the atmosphere.

1059403
Thus as the pressure within the casing
10 builds up, the bellows 17 compresses downwardly
as viewed in the dra~ng and, assuming that the
position of the valve member 21 does not change,
the latter is thus unseated and the surplus
passes from the upper chamber through the
aperture in the surface 20, into the bellows 17
whence it escapes into the atmosphere through the
port 19. Therefore air at a constant pressure, equal
to or less than that of the supply, is supplied
through the delivery pipe 14 to the system.
I~ now the position o~ the valve member 21
i8 permitted to change owing to a change in the positio~
of the ~loat or the cam 23, the pressure of the air
supply needed to unseat the valve member 21 changes
a¢cordingly.
It will be appeciated that upward movement
o~ the valve member 21 as seen in the drawing causes
a decrease in the resultant pressure in the upper
chamber while downward movement causes an increase.
If necessary a spring may be provided
within the bellows 17 to give enhanced accuracy.

1059403
It will be realised that a very small
force is sufficient to move the valve member 21 and
that that force is not materially affected by the
pressure existing in the upper chamber and acting on
the valve member.
, '.
The valve is set up for delivery of air
at a predetermined pressure by adjusting the collar
24 and thus the height of the casing 10 relative to,
in this case, the cam 23 which itsel~ determines the
height of the valve member 21 according to a certain
condition in the system.
It is not intended to limit the invention
to the above example only, many variations, such
as might readily occur to one skilled in the art
being possible without departing ~rom the scope
of the invention.
Thus for example, the bellows can be replaced
by a plurality of sealed tubular members mounted in
telescopic relationship such that the internal volume
o~ the memb so ~ormed is variable.
. . , . . . . ~. - -