U.S. patent number 3,756,576 [Application Number 05/118,162] was granted by the patent office on 1973-09-04 for apparatus for charging a liquid with gas.
Invention is credited to Franco Tremolada.
United States Patent |
3,756,576 |
Tremolada |
September 4, 1973 |
APPARATUS FOR CHARGING A LIQUID WITH GAS
Abstract
In producing carbonated water, CO.sub.2 gas from a storage tank
is introduced into a charging chamber together with a water spray
delivered by a double-acting pump. The charged water is collected
in a reservoir from which a portion of the evolving gas is directed
to the pump for reciprocating same; on its way to the pump, this
gas flow passes through a pair of control valves held open by gas
pressure from another reservoir outlet as long as the liquid in
that reservoir remains below a predetermined level. When this level
is reached, a float cuts off the gas pressure so that the control
valves close to arrest the pump. Reciprocation of the pump piston
is controlled by a switching valve which is temporarily locked in a
terminal phase of each piston stroke to stress a spring in a
lost-motion coupling between the piston and the valve body, the
subsequent release of the locking detent enabling the instant
reversal of the switching valve by snap action.
Inventors: |
Tremolada; Franco (Milan,
IT) |
Family
ID: |
11177718 |
Appl.
No.: |
05/118,162 |
Filed: |
February 23, 1971 |
Foreign Application Priority Data
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Feb 26, 1970 [IT] |
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21165 A/70 |
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Current U.S.
Class: |
261/35;
261/DIG.7; 261/82 |
Current CPC
Class: |
B01F
25/105 (20220101); B67D 1/0057 (20130101); B01F
23/2363 (20220101); B01F 23/2362 (20220101); Y10S
261/07 (20130101) |
Current International
Class: |
B01F
3/04 (20060101); B01F 5/00 (20060101); B01f
003/04 () |
Field of
Search: |
;261/DIG.7,35,82 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Miles; Tim R.
Assistant Examiner: Markowitz; Steven H.
Claims
I claim:
1. In a system for charging a liquid with gas, in combination:
a supply of liquid to be charged;
storage means containing a charging gas under pressure;
a charging chamber provided with a first inlet for said liquid and
a second inlet connected to said storage means;
a pump for delivering said liquid to said chamber, said pump
comprising a cylinder with a double-acting piston having a pair of
spaced-apart heads, said cylinder being provided with an internal
partition between said heads defining with the latter a pair of
inner compartments each having an entrance port connected to said
supply and an exit port connected to said first inlet, said
cylinder having end walls defining with said heads a pair of outer
compartments;
a source of motive fluid for said pump;
valve means operable to connect said source alternately to said
outer compartments for reciprocating said piston;
a reservoir for gas-charged liquid connected to said chamber;
sensing means responsive to the amount of liquid in said
reservoir;
and control means for said valve means operable by said sensing
means to cut off the flow of motive fluid to said pump upon said
amount of liquid reaching a predetermined magnitude.
2. The combination defined in claim 1 wherein said pump is provided
with a first pair of check valves ahead of said entrance ports and
a second pair of check valves beyond said exit ports.
3. The combination defined in claim 1 wherein said pump is provided
with a high-pressure conduit originating at said source and with a
low-pressure conduit opening into the atmosphere, said valve means
including a switching valve for alternately connecting said outer
compartments to said high-pressure conduit and said low-pressure
conduit, respectively, said valve means further including a pair of
shut-off valves in said conduits controed by said sensing
means.
4. The combination defined in claim 3 wherein said reservoir is
provided with a discharge line for evolving gases with a restricted
termination opening into the atmosphere and with branches leading
to said shut-off valves, said sensing means comprising a floating
member in said reservoir positioned to obstruct said discharge
lines upon a rise of the liquid to a predetermined level.
5. The combination defined in claim 4 wherein said source is an
outlet of said reservoir connected to said high-pressure
conduit.
6. The combination defined in claim 3 wherein said piston has a
hollow rod interconnecting said heads, said switching valve
comprising a valve body provided with an axially extending stem
lodged in said rod, a spring-loaded lost-motion coupling in said
rod linking same with said stem for temporarily immobilizing same
in a terminal phase of each reciprocating stroke of the piston,
deactivation of said detent means in a dead-center position of said
piston resulting in an instant reversal of said switching
valve.
7. The combination defined in claim 6 wherein one of said end walls
is formed with a socket communicating with said conduits and
opening into a passage leading to the proximal one of said outer
compartments, said pump being further provided with a channel
connecting said socket with the distal one of said outer
compartments, said valve body being shiftable in said socket for
alternately connecting said conduits with said passage and said
channel, respectively.
8. The combination defined in claim 7 wherein said socket has a
wall surface provided with terminations of said conduits and said
channel at axially spaced locations, the termination of said
channel being bracketed by the terminations of said conduits, said
valve body having an annular shoulder bearing upon said wall
surface in a fluidtight manner and surrounding a recess confronting
one pair of adjoining terminations in a first postion and another
pair of adjoining terminations in a second position.
9. The combination defined in claim 8 wherein said valve body
comprises a frame parallel to and spaced from said wall surface, a
disk member and a ring member seated side by side in said frame
with relative transverse mobility and with formation of a
peripheral gap therebetween, said ring member projecting toward
said wall surface to form said annular shoulder, and an elastically
deformable annular gasket in said gap tending to spread said
members apart against said wall surface and an opposite surface of
said socket.
10. The combination defined in claim 9 wherein said disk member has
a concave front face next to said ring member forming part of said
recess, said disk member further having a rear face with a
depression accessible to high-pressure gas in said socket for
urging both said members toward said wall surface.
11. The combination defined in claim 6 wherein said lost-motion
coupling comprises a guide tube for said stem rigid with one of
said end walls, said tube being formed with a lateral hole and
being provided with a ball of a diameter greater than the wall
thickness of said tube seated in said hole, said stem having a pair
of axially spaced incisions alternately engageable by said ball for
locking said valve body in either of two operating positions
thereof, a ferrule inside said rod surrounding said tube in the
region of said hole with frictional fit but axial displaceability
between two extreme positions out of line with said ball, and a
pair of axially spaced abutments in said rod engaging said ferrule
in opposite terminal piston positions for moving through an
intermediate locking position aligned with said ball to immobilize
said stem temporarily just before the end of each stroke.
12. The combination defined in claim 11 wherein said abutments form
part of two relatively movable elements in said rod, said coupling
including an expanding spring tending to spread said elements
axially apart, said elements being respectively engageable with
said stem in opposite terminal positions of said piston for
shifting said valve body upon movement of said ferrule past said
locking position.
13. The combination defined in claim 12 wherein said elements are a
first sleeve, coaxially surrounding said stem and said ferrule, and
a second sleeve in line with said guide tube, said valve body
having a pair of projections alongside said stem engageable by said
first sleeve, said stem having a flanged end engageable by an
internal flange of said second sleeve.
Description
My present invention relates to a pumping system to be used in an
apparatus for charging a liquid with gas, e.g. in the production of
carbonated water.
An object of my invention is to provide means in such a system for
supplying water or other liquid under constant pressure to a
charging chamber for as long as a reservoir connected with that
chamber contains less than a predetermined volume of charged
liquid; whenever the reservoir is sufficiently filled, the liquid
supply is to be cut off in a manner enabling instant resumption of
liquid flow at the prescribed pressure.
Another object of my invention is to provide a double-acting pump
of simple design and easy maintenance for delivering the liquid to
that chamber under the pressure of e charging gas (such as carbon
dioxide) itself, e.g. as evolving within the reservoir from the
charged liquid, thus eliminating the need for any external power
source.
In accordance with this invention I provide, in a liquid-feeding
system of the general character described, a pump in which a pair
of inner compartments and a pair of outer compartments are defined
by a pair of piston heads on opposite sides of an internal
partition of a cylinder or housing, the piston being reciprocated
by a motive fluid which advantageously consists of a portion of the
evolving charging gas and which is alternately directed by one or
more valves to the two outer compartments. A supply of liquid, such
as a water tap, communicates through respective entrance ports with
the two inner compartments from which the liquid is alternately
ejected through respective exit ports to the mixing chamber. In the
reservoir connected with that chamber, a sensing device such as a
float valve cuts off the flow of motive fluid to the pump as soon
as a predetermined amount of charged liquid has been stored.
The motive fluid, particularly if constituted by the charging gas,
can be simply released into the atmosphere via a low-pressure
conduit to which the two outer compartments are alternately
connected at the end of each piston stroke by the valve assembly
which simultaneously reverses the connection of the gas supply to
these compartments; aside from a switching valve required for this
operation, the valve assembly may include a pair of shut-off valves
in the two conduits controlled by the level sensor in the reservoir
to stop and to restart the pump.
Another important feature of my invention resides in the provision
of a spring-loaded lost-motion coupling between the pump piston and
the switching valve for reversing the latter in a terminal piston
position, this coupling including a detent mechanism which locks
the piston in a terminal phase of its stroke to stress the loading
spring preparatorily to a sudden release to trip the valve by snap
action upon a subsequent deactivation of the detent. For ths
purpose I prefer to provide the piston with a hollow rod into which
a stem rigid with the movable valve body axially extends for
alternate engagement by a pair of spaced-apart abutments within
that rod, these abutments being advantageously formed by two
sleeves held separated by an interposed compression spring and
severing also to shift ferrule on a stationary guide tube
surrounding the valve stem, the ferrule being effective in an
intermediate position to lock the stem temporarily against axial
motion by acting upon one or more retaining balls lodged in lateral
holes of the tube and engaging in either of two axially spaced
incisions on the stem.
The above and other features of my invention will be described in
detail hereinafter with reference to their accompanying drawing in
which:
FIG. 1 is a diagrammatic overall view of a system for producing
carbonated water in accordance with my invention;
FIG. 2 is an axial sectional view of a pump included in the system
of FIG. 1, shown in the upper-dea-center position of its
double-acting piston;
FIG. 3 is a view generally similar to FIG. 2 but limited to the
region close to the pump axis, showing the piston in an
intermediate descending position;
FIG. 4 is a view similar to FIG. 3 with the piston in a terminal
phase of its descent;
FIG. 5 is another such view showing the piston at lower dead
center;
FIG. 6 is a similar view showing the piston in a terminal phase of
its ascending stroke;
FIG. 7 is a framentary cross-sectional view taken on the line
VII--VII of FIG. 2;
FIG. 8 is a similar cross-sectional view taken on the line
VIII--VIII of FIG. 5;
FIGS. 9 and 10 are cross-sectional views of a first shut-off valve,
inserted in a high-pressure conduit for supplying gas to the pump,
in closed and in open position, respectively; and
FIGS. 11 and 12 are analogous cross-sectional views of a second
shut-off valve located in a low-pressure conduit for venting the
spent gas to the atmosphere.
In FIG. 1 I have shown at R a supply of water, which could be a
continuously open tap on a water pipe, connected via a check valve
42 in a pipe 41 and a pair of branch pipes 41', 41" with additional
check valves 42', 42" to two inner compartments 14, 15 of a pump 1,
these compartments being defined inside a cylinder 4 by a
transverse partition 8 and two heads 11, 12 (see also FIG. 2) of a
double-acting piston. This piston further forms with the pump
housing a pair of outer compartments 13, 16, compartment 13 being
defined by the top wall 7 of the housing and by the upper piston
head 11 whereas compartment 16 is bounded by the lower piston head
12 and the bottom wall 6 of the housing. Inner compartments 14 and
15 also have exit ports leading to branches 43', 43" of a discharge
pipe 43 which contain respective check valves 44' and 44"; the
several check valves referred to prevent any return flow of liquid
out of the pump housing by way of the entrance ports of
compartments 14 and 15.
The water discharged via pipe 43' arrives under pressure at a spray
nozzle 45 of a charging chamber 2 where it is atomized and
intimately mixed with a flow of charging gas, specifically
CO.sub.2, supplied from a tank B via a pipe 46 containing a
pressure gauge B'. The mixture of water and gas passes from chamber
2 through drain 47 into a reservoir 3 which it is desired to keep
filled up to a maximum level L. A syphon tube 48 rises from the
bottom of the reservoir to facilitate the drawing of liquid
therefrom to a destination U; two conduits 49 and 50 extend from
the top of the reservoir to carry off evolving gases. The inlet end
of conduit 50 confronts a stopper 57 within a nipple 56, this
stopper being carried on a stem 55 of a floating ball 54 so as to
obstruct that inlet whenever the liquid in the reservoir rises to
the level L.
The reciprocation of the pump piston is controlled by a switching
valve 18 in the base of the pump housing 4, this valve lying at the
junction of a high-pressure conduit 19 connected with line 49 via a
shut-off valve 51, a low-pressure conduit 21 leading to the
atmosphere by way of another shut-off valve 52 and an extension
21', a chennel 21 extending to the distal (i.e. upper) outer
compartment 13, and a passage 33' communicating with the proximal
(i.e. lower) outer compartment 16. with shut-off valves 51 and 52
open, switching valve 18 operates in a manner more fully described
hereinafter to direct gas from conduit 19 alternately into channel
20 and passage 33' to pressurize one of the two outer compartments
while venting the other of these compartments through conduit 21
and its extension 21' to the atmosphere. Valves 51 and 52 are
controlled by gas pressure from line 50 via branches 50' and 5"
thereof, being held open whenever the inlet of that line is
unblocked whereby the pump 1 keeps operating until the liquid in
reservoir 3 reaches the level L; when this occurs, stopper 57
obstructs the tube 50 which has a restricted termination 53 opening
into the atmosphere by way of conduit extension 21'.
The structural details of switching valve 18 and its control
mechanism will now be described with reference to FIGS. 2-8. As
shown particularly in FIGS. 2-6, the piston has a hollow stem 10
interconnecting its heads 11 and 12 which bear in a fluid-tight
manner upon the inner wall surface of cylinder 4 by way of packing
rings 11a, 12a. Similar packing rings 5' and 5" between the
cylinder wall and the end walls 6 and 7 of the pump housing seal
the interior thereof against the atmosphere while a further packing
ring 9 engages the piston rod 10 in partition 8.
The bottom wall or base 6 of the pump housing forms a socket 17
which accommodates the body 27 of switching valve 18 and, like that
body, is of generally prismatic shape with a pair of parallel wall
surfaces 17', 17" separated by a distance h (FIGS. 7 and 8)
slightly exceeding the thickness of the frame-shaped valve body.
Two independently transversely displaceable members 37 and 38,
embraced by a mounting ring 36 snugly fitting within the opening 34
of valve body 27, are normally separated by a small gap, this
separation being maintained by an elastically deformable annular
gasket 39 received in a peripheral recess of the generally
disk-shaped member 37. The other member 38, confronting the socket
surface 17', is ring-shaped and forms an annular shoulder
projecting toward that surface beyond the frame 27 and the mounting
ring 36. Disk member 37 has a concave front face next to ring
member 38, this front face forming a recess 40 as a continuation of
the opening of the ring member; the opposite, rear face of member
37 has a shallow depression 37' confronting the wall surface 17".
The terminations of gas conduits 19 and 21 and of connecting
channel 20 open at axially spaced locations into the socket 17 at
its surface 17', the termination of channel 20 being bracketed by
those of conduits 19 and 21 in such a way that this channel
communicates only with conduit 19 in a raised position of valve
body 27 (FIG. 7) and only with conduit 21 in a lowered position of
that valve body (FIG. 8). In the first instance, gas pressure from
conduit 19 enters the recess 40 and urges the disk 37 into firm
contact with surface 17" while also deforming the gasket 39 to
press the ring 38 against surface 17'; in the second instance the
high-pressure gas enters the socket 17 directly, outside the valve
members 37 and 38, and forces its way to the depression 37' of disk
37 to urge it together with ring 38 into sealing engagement with
surface 17'. In each case, therefore, gas leakage between the
high-pressure and low-pressure sides of the system will be
minimized.
A stem 26 rigid with valv body 27 extends axially upwardly into the
hollow piston rod 10 and terminates at its upper end in a beveled
shoulder 26'. The lower part of the stem is surrounded by a guide
tube 23 which has a base 22 held onto housing wall 6 by a retaining
plate 22'. Tube 23 is provided near its upper end with two or more
holes 24 accommodating balls 25 whose diameter slightly exceeds the
wall thickness of the tube and which are partly receivable in
annular grooves 29 and 29' formed at axially spaced locations in
the stem 26. A furrule 30 slidably embraces the tube 23 and is
frictionally retained thereon by at least one of two axially spaced
packing rings 23', 23" engageable with a portion 30' thereof having
a reduced inner diameter. The lower end of tube 23 fits between a
pair of humps 27' of valve body 27 in a manner enabling circulation
of gas between socket 17 and compartment 16 via a clearance 33 in
any position of valve body 27 and piston head 12. A sleeve 35,
freely slidable within piston rod 10, has a bottom flange 32 with
an inwardly projecting annular shoulder 32' by which it comes to
rest on the humps 27' in the terminal phase of the descending
piston stroke (FIG. 4). Another sleeve 28, also freely slidable in
piston rod 10, surrounds the upper end of stem 26 and is urged away
from sleeve 35 by an enveloping coil spring 31; sleeve 28 is in
line with tube 23 and has its lower end formed with a beveled
internal shoulder 28' engageable with the beveled shoulder 26' of
stem 26 in the terminal phase of the ascending piston stroke (FIG.
6). The outer diameter of sleeve 28 is the same as that of ferrule
30 which is engaged by the sleeve 28 toward the end of the
descending stroke as shown in FIG. 4.
As seen in FIGS. 9 and 10, valve 51 has a housing 60 into which the
conduits 19, 49 and 50' open, an insert 61 within this housing
forming a seat for a valve cone 62 which is urged by a spring 59
into a postion (FIG. 9) blocking communication between conduits 19
and 49. A piston head 58 secured to valve cone 62 drives the latter
upwardly, against the force of spring 59, in respone to gas
pressure in conduit 50' so that gas from conduit 49 enters the
conduit 19 (FIG. 10). In an analogous manner, as shown in FIGS. 11
and 12, the housing 60' of valve 52 has an insert 61' which forms a
seat for a valve cone 62' urged by a spring 59' into a closing
position to disconnect conduit 21 from its extension 21'; in the
presence of gas under pressure in conduit 50", a piston head 58'
rigid with valve cone 52' is driven upwardly to vent the conduit 21
to the atmosphere via its extension 21'.
With valves 51 and 52 open, the operation of the pump shown in
FIGS. 2-8 is as follows.
In the upper-dead-center position illustrated in FIG. 2, the valve
body 27 has been raised by the upward entrainment of its stem 26 by
the sleeve 28 through the interengagement of their respective
flanges 26' and 28'. In this position of valve 18, also shown in
FIG. 7, gas under pressure of conduit 19 is directed by valve
members 37 and 38 into channel 20 and reaches the upper outer
compartment 13 to drive the piston 0-12 down. At this stage the
ferrule 30 is elevated above its locking position, through its
engagement with the internal shoulder 32' of sleeve 35, so that the
balls 25 are not restrained against limited outward movement to an
extent permitting an axial shifting of stem 26. Since, however, the
valve body 27 is frictionally retained in its socket 17 by the
gaspressure, as previously explained, there is no tendency for the
stem to shift downwardly even after the piston has begun its
descent so that the flange 28' of sleeve 28 disengages the flange
26' of the stem as shown in FIG. 3.
Next, as illustrated in FIG. 4, the piston reaches a position in
which the lower end of sleeve 28 comes to rest on ferrule 30 to
drive its reduced-diameter portion 30' down past an intermediate
locking position in which it engages the retaining balls 30'.
Substantially simultaneously with the temporary immobilization of
its valve body 27, its humps 27' intercept the sleeve 35 to prevent
any further descent thereof so that spring 31 is compressed between
the two sleeves. Shortly thereafter, just before the upper piston
head 11 reaches the top of stem 26, ferrule 30 is depressed
sufficiently to release the balls 25 whereupon the spring 31
instantly expands and drives the valve body 27 into its alternate
position (FIG. 8) by a snap action.
With the piston now in its lower-dead-center position, as
illustrated in FIG. 5, its stroke is reversed as high-pressure gas
from conduit 19 enters the socket 17 and finds its way into the
lower outer compartment 16 through the clearance 33 between the
hump 26' and the tube base 22, this clearance corresponding to the
passage 33' indicated diagrammatically in FIG. 1. With the piston
rising into the position of FIG. 6, the shoulder 32' of sleeve 35
entrains the ferrule 30 upwardly so that, again the valve stem 26
is temporarily immobilized as the spring 31 is being compressed
between the two sleeves 28 and 35. Sleeve 28, being retained at
this point by its flange 28' coacting with flange 26' of stem 26,
cannot follow the rise of the piston until the latter reaches its
top-dead-center position shown in FIG. 2 whereupon the release of
the detent balls 25 by the lifting of ferrule 30 allows the spring
31 to re-expand and, again by snap action, to restore the valve 18
to its previous position. The cycle can then be repeated.
It will thus be seen that I have provided a pump which instantly
reverses the stroke of its double-acting piston so that the flow of
water to the charging chamber 2 is virtually continuous and under
constant pressure. Naturally, this pump could also be used in a
system in which the liquid propelled by the pump is used for a
different purpose, yet the availability of gas pressure to drive
the pump is particularly advantageous in an apparatus for making
carbonated water.
Some of the features described above, including the reversal of the
pumpint stroke under the control of a floating member,could also be
realized with valves that are operated electrically instead of
pneumatically, e.g. with the aid of a microsensitive switch
operated by the float 54. The driving gas entering the conduit 49
could also be taken directly from the tank B rather than from the
reservoir 3.
* * * * *