Abstrict A flow meter means for flowing columns of mixed liquids and gases
comprising an elongate flow tube between upstream and downstream
sections of a fluid conducting line, an elongate return duct with
upstream and downstream ends communicating with the sides of the
tube at longitudinally spaced fronts, a plurality of plugs slidably
engaged in the tube, and shiftable through the duct, means to intermittently
move plugs from the upstream end of the duct into the tube and to
move plugs from the tube into the downstream end of the duct and
means to count the number of plugs moved into and out of the tube
and to time the rate at which the plugs move through the tube.
Claims Having described my invention, I claim:
1. An elongate fluid flow meter with upstream and downstream ends,
comprising an elongate flow tube with upstream and downstream ends
substantially coextensive with the meter means, means connecting
the upstream and downstream ends of the tube with upstream and downstream
sections of a fluid line, an elongate transport duct at the exterior
of the tube with upstream and downstream ends communicating with
sides of the tube adjacent the upstream and downstream ends thereof;
a plurality of plugs shiftable longitudinally in and through the
duct and tube, intermittently operable plug engaging transfer means
actuatable to synchronously transfer a plug transported through
the duct to the end thereof into the tube and to transfer a plug
transported through the tube to the downstream end thereof into
the duct, control means for the transfer means comprising a plug
sensing device at a predetermined position longitudinally of the
tube, connected with the transfer means and operable to sense the
presence of a plug in the tube at said position and cause the transfer
means to actuate whereby plugs are transferred into and out of the
upstream and downstream ends of the tube without substantially impeding
of the flow of fluid through the tube and means to count and time
intervals between plugs sensed by the device.
2. A meter as set forth in claim 1 wherein said transfer means
includes an elongate shiftable plug-engaging member at the downstream
end of the tube on an axis substantially normal to the axis of the
tube and at that side of the tube opposite from the downstream end
of the duct, said member normally occurring outward of the tube
and shiftable transversely therethrough to engage a plug in the
tube adjacent thereto and move it laterally into the duct when the
transfer means is actuated.
3. A meter as set forth in claim 2 wherein said transfer means
includes retaining means at the upstream end of the meter releasably
retaining the upstream most plug in the duct laterally outward of
the tube, said duct accommodating a series of plugs in substantial
bearing contact whereby said upstream most plug is displaced from
the duct urged by the retaining means when a plug is transferred
from the tube into the duct at the downstream end of the meter.
4. A meter as set forth in claim 2 including retaining means at
the downstream end of the duct and engageable with the downstream-most
plug in the duct to prevent downstream movement of that plug in
the duct.
5. A meter as set forth in claim 2 wherein said transfer means
includes retaining means at the upstream end of the meter releasably
retaining the upstream-most plug in the duct laterally outward of
the tube, said duct accommodating a series of plugs in substantial
bearing contact whereby said upstream-most plug is displaced from
the duct and urged by the retaining means when a plug is transferred
from the tube into the duct at the downstream end of the meter,
and retaining means at the downstream end of the duct and engageable
with the downstream-most plug in the duct to prevent downstream
movement of that plug in the duct.
6. A meter as set forth in claim 1 wherein said transfer means
includes an elongate axially shiftable plug-engaging member at the
downstream end of the tube on an axis substantially normal to the
axis of the tube and at that side of the tube opposite from the
downstream end of the duct, said member normally occurring outward
of the tube and shiftable transversely therethrough to engage a
plug in the tube adjacent thereto and move it laterally into the
duct, a second elongate axially shiftable plug-engaging member at
the upstream end of the duct on an axis substantially normal to
the axis of the tube and shiftable transversely into and through
the duct to engage the upstream-most plug in the duct and move it
laterally into the tube when the transfer means is actuated.
7. A meter as set forth in claim 6 wherein said transfer means
further includes a third elongate axially shiftable plug-engaging
part at the downstream end of the duct in axial alignment therewith
and shiftable from a normal position downstream from the duct axially
upstream into the duct to engage a plug transferred from the tube
into the duct and advance that plug and adjacent plugs upstream
in the duct.
8. A meter as set forth in claim 7 including retaining means at
the upstream and downstream ends of the meter engaging the upstream-most
and downstream-most plugs in the duct and releasably retaining said
plugs laterally outwardly from said tube.
9. A meter as set forth in claim 1 wherein the transfer means includes
a plug-engaging arm supported on an axis at the downstream end portion
of the meter upstream of the downstream end of and between the tube
and the duct and selectively shiftable from a normal position spaced
from the interior of the tube, laterally inwardly, downstream and
thence laterally outwardly into and through the tube and thence
laterally inwardly and upstream in the duct to engage a plug in
the downstream portion of the tube and transfer it into the downstream
portion of the duct and drive means to move said arm from and to
its normal position.
10. A meter as set forth in claim 1 wherein said transfer means
includes retaining means at the upstream end of the meter releasably
retaining the upstream-most plug in the duct laterally outward of
the tube, said duct accommodating a series of plugs in substantial
bearing contact whereby said upstream-most plug is displaced from
the duct urged by the retaining means when a plug is transferred
from the tube into the duct at the downstream end of the meter.
11. A meter as set forth in claim 9 wherein said transfer means
includes a second plug-engaging arm supported on an axis at the
upstream end of the meter downstream of the upstream end of and
between the tube and duct and selectively shiftable from a normal
position in the duct downstream of the upstream-most plug in the
duct, and selectively shiftable out of the duct laterally toward
said tube whereby said upstream-most plug is moved into the tube
and thence shiftable laterally outwardly relative to the tube and
laterally inwardly into the duct to its normal position downstream
of the next upstream-most plug in the duct and drive means for the
second arm.
12. A meter as set forth in claim 1 wherein said transfer means
includes a star wheel rotatably supported between the duct and tube
upstream of the downstream ends thereof on an axis normal to the
common plane of the tube and duct and having radially extending
plug-engaging arms moveable laterally into, downstream and thence
laterally outward of the tube and thence laterally into the upstream
in and thence laterally out of the duct, one of said arms engaging
a plug in the downstream end of the tube and moving it ito the downstream
end of the duct each time the transfer is actuated and drive means
operable to rotate the wheel a portion of predetermined one revolution
each time the transfer means is actuated.
13. A meter as set forth in claim 12 wherein said transfer means
includes a second star wheel rotatably supported between the duct
and tube downstream of the upstream ends thereof on an axis normal
to the common plane of the tube and duct and having radially extending
plug-engaging arms moveably laterally into, upstream in and thence
laterally outward of the duct and thence laterally into and downstream
in and thence laterally out of the duct, one of said arms engaging
the upstream-most plug in the duct and the downstream side thereof
and moving it into the upstream end of the tube each time the transfer
means is actuated and drive means operable to rotate the second
wheel a predetermined portion of one revolution each time the transfer
means is actuated.
Description This invention has to do with a flow meter and is more particularly
concerned with an improved meter adapted to accurately measure the
flow rate and volume of a fluid mixture of liquid and gas.
The prior art has provided practical and effective flow meters
for liquids and for gas, but to the best of my knowledge and belief
said art has failed to provide a simple, economical and practical
meter capable of accurately and effectively indicating the volume
of flowing mixtures of liquid and gas.
It is understood that failure of the prior art to provide effective
metering means for liquid and gas mixtures resides in the wide differences
in the physical characteristics of liquids and gases. For example,
gases are inherently less dense or lighter than liquids, are more
compressible than liquids and are more fluid than liquids. As a
result of the above, while it is simple and practical to establish
a mechanical metering means or structure to effectively measure
the flow rate and volume of a liquid or of a gas, embodying substantially
uniform physical characteristics, great and difficult to overcome
problems or complications are presented in the establishment of
fluid metering means intended to measure the flow rate and volume
of fluids comprising mixtures of gas and liquid and where the distinct
physical characteristics of each is present. For example, turbine
or vane-type meter structures and positive displacement piston-type
metering means, which are designed and intended to measure the flow
rate and volume of a liquid, are incapable of properly measuring
the flow rate and volume of lighter, compressible gases. Further,
such metering means are such that the presence of any appreciable
volume of light, compressible gas in the liquids to be measured
thereby adversely affects their effectiveness and accuracy. Such
adverse effects are oftentimes undetected. When such effects are
detected, efforts are made to compensate for resulting errors in
the meter outputs by taking samples of the fluid mixtures, determining
the ratio of gas to liquid in such samples and then calculating
what the average or means volumes of liquids and gases might be
with respect to the meter output. Such procedures presuppose that
the operation of the meters are not slowed or adversely affected
by the presence of gases in the liquids or, attempts are made to
determine the extent of such adverse operational effects in the
meters and the findings of such attempts are sought to be incorporated
in the calculations employed to determine the actual volumes of
the gases and liquids being measured.
To date, the most effective means and/or procedures commonly practiced
in the measurement of gas and liquid mixtures is to select a suitable
liquid handling flow meter, place it in the pipe or line through
which the liquid and gas mixture is conducted and to set and adjust
the meter so that its read-out or output approximates the means
total volume of the mixture conducted therethrough. Adjusting and
setting of such meters is effected by an apparatus commonly referred
to as a Meter Tester which comprises an elongate by-pass flow duct
of known volumetric extent related to the line upstream of the meter
to be tested and which includes means for introducing and removing
plugs at its upstream and downstream ends. The plugs serve to separate
predetermined volumes of the fluid mixtures in the duct and flow
longitudinally therewith, through the duct. Finally, such apparatus
include valve means to selectively establish flow through the by-pass
duct and line. With such apparatus, it is possible to selectively
by-pass plug defined test volumes of the mixture through the duct,
time the movement of the volumes therethrough and calculate the
rate and/or volume of flow in the line. Thereafter, the meter can
be adjusted so that its read-out corresponds to the calculated flow
in the line.
The obvious shortcoming in the above procedure resides in the fact
that it does not and cannot take into account or compensate for
variations in the relative volumes of liquids and gases that are
likely to occur in the mixture or in variations in the operation
of the meters that are likely to occur as a result of variations
in the temperatures of the mixtures and which result in disproportionate
expansion of the mixed liquids and gases.
An object and feature of my invention is to provide a novel fluid
meter engageable in a fluid conducting line and which operates to
effectively and accurately measure the volume of a fluid mixture
of liquid and gas flowing through said line and which is substantially
unaffected by the volumetric ratio of liquid and gas in said mixture.
A further object and feature of my invention is to provide a meter
of the character referred to which includes an elongate flow duct
of predetermined longitudinal and volumetric extent engageable between
spaced upstream and downstream sections of a flow line in communication
therewith, a plurality of plugs and means to intermittently and
synchronously introduce and remove plugs from the upstream and downstream
ends of the duct and counting means to count and record the number
of plugs conducted through the duct.
Still another object of my invention is to provide a meter of the
character referred to above wherein the means to introduce and remove
the plugs from the duct comprises upstream and downstream plug transfer
means at the upstream and downstream ends of the duct and plug transport
means between said downstream and upstream transfer means.
It is an object and feature of my invention to provide a meter
of the character referred to wherein the duct, transfer and transport
means are in communication with each other and are sealed from outside
pressures whereby a pressure balanced loop through which the plugs
circulate is established.
Still further, it is an object of my invention to provide a meter
of the general character referred to above which further includes
drive means for the transfer means, sensing means to sense the location
of plugs in the duct and adapted to control operation of the drive
means and timing means related to the sensing and/or the above noted
counting means whereby recorded data, comprising the number of plugs
conducted through the duct and the time which lapses between the
movement of the plugs from one position to another within the duct,
is provided and from which both the rate and volume of fluid through
the meter can be computed.
It is a general object and feature of my invention to provide a
meter of the general character referred to which is simple and economical
to manufacture and maintain and a meter which is accurate, dependable
and durable in operation.
The foregoing and other objects and features of my invention will
be fully understood and appreciated from the following detailed
description and illustrations of typical preferred forms and applications
of the invention throughout which description reference is made
to the accompanying drawings, in which:
FIG. 1 is a view of my invention with portions shown in sections
to better illustrate certain details of the structure;
FIG. 2 is a view similar to FIG. 1 showing another form of my invention;
FIG. 3 is a view similar to a portion of FIG. 2 and showing a modified
construction;
FIG. 4 is a view similar to FIGS. 1 and 2 showing yet another form
of the invention;
FIG. 5 is a view taken as indicated by line 5--5 on FIG. 4; and
FIG. 6 is a view taken as indicated by line 6--6 on FIG. 4.
In the form of the invention shown in FIG. 1 the meter M that
I provide is a unitary structure arranged between spaced opposing
ends of upstream and downstream sections of a flow line L.sup.u
and L.sup.d. The meter M includes, basically, an elongate flow tube
T with upstream and downstream ends communicating with the sections
L.sup.u and L.sup.d of the flow line, an elongate transport duct
D extending longitudinally of the tube T and having an inlet end
communicating with the downstream end portion of the tube T at one
side thereof and an outlet end communicating with the upstream end
portion of the tube T, at one side thereof. The meter M next includes
a plurality of spherical plugs P corresponding substantially in
diametric extent with the interior of the tube T to establish sliding
sealing engagement therein, injector and ejector transfer means
I and E at the upstream and downstream ends of tube and duct T and
D and operating means O for the means I and E.
The tube T is a straight cylindrical length of pipe or tubing with
a smooth interior wall surface and is provided with coupling flanges
F at its end to facilitate connecting the meter with the opposing
related ends of the sections L.sup.u and L.sup.d of the flow line,
which sections are provided with complimentary flanges F'. The flange
type connecting means is only intended to be illustrative of one
typical form of connecting or coupling means that can be employed.
In practice, the interior of the tube can be coated with a suitable
plastic or the like which presents a smooth surface and has an extremely
low coefficient of friction with the plugs, that is, with the material
of which the plugs P are established or coated with.
The upstream and downstream end portions of the tube T are provided
with lateral openings 10 and 11 through which the plugs P can be
freely moved, into and out of engagement in the tube. The openings
10 and 11 are shown as occurring in the top side of the tube.
The transfer duct is an elongate tubular part with an elongate
central portion 12 spaced laterally from the central portion of
the tube T, a downwardly turned upstream or outlet end 14 communicating
with the opening 10 of the tube and a downwardly turned downstream
or inlet end 15 communicating with the opening 11 in the tube. The
duct is preferably sufficiently larger in cross-section than the
diametric extent of the plugs and is such that the plugs P are freely
received therein and can move freely therethrough. In practice,
the duct can be of any desired cross-section and, as shown, the
plugs need not seal therewith.
In practice, there is provided a number of plugs sufficient to
substantially fill the duct, from one end thereof to the other,
with said plugs in substantial bearing contact with each other and,
in addition thereto, a limited number of extra plugs which are adapted
to occur in the tube, in longitudinal spaced relationship therein
and which are adapted to move downstream in the tube when the meter
is in operation.
In practice, and to facilitate free operating of the means I and
E, the number of plugs P in the duct is in fact one plug short or
shy of completely filling the duct.
The injector means I of the transfer means includes a releasable
retaining means R within the duct D adjacent its outlet end and
adapted to releasably retain the plug P at the outlet end of the
duct, in said duct, and clear or out of interfering engagement in
the flow passage of the tube T. The means R can vary in form and
construction and is shown as including an annular, flexibly and
resilient, flange-like ring 16 suitably mounted in the duct and
such that it normally yieldingly engages about and supports the
plug in the duct which is positioned adjacent thereto. The ring
16 of the means R is such that it will yieldingly stretch and permit
the passage of the plug P related thereto when the plug is forcibly
urged downwardly.
The next I next includes a drive means to engage and forcibly urge
the plug P related to the means R, downwardly by or through the
means R and into the tube T. In practice, the drive means preferably
includes a hydraulic or pneumatic double acting cylinder and ram
unit 20 arranged in vertical alignment with the opening 10 in the
tube, with its cylinder fixed to and projecting upwardly from the
end portion 14 of the duct and with its ram projecting downwardly
and shiftably vertically in and through said end portion 14 of the
duct.
With the means I briefly described above and illustrated in the
drawings, it will be apparent that when the unit 20 is energized,
the plug P engaged by the means R is urged downwardly through the
means R and into the tube T and that thereafter, when the unit 20
is operated to return its ram from a down, actuated position within
the duct to normal unactuated position where it is up and clear
of the duct, the next adjacent plug P in the duct is free to advance
downwardly and into engagement with the means R.
The means E at the other, downstream end of the tube and duct includes
a retaining means R' which can be substantially identified with
the means R and a cylinder and ram unit 20' substantially identical
with the unit 20 except that the unit 20' is arranged below the
tube T in axial alignment with the opening 11 and is operable to
urge plugs in the tube T upwardly through the means R' and into
the duct D. The cylinder of the unit 20' is mounted below the tube
and the ram of that unit is shiftable from a lower unactuated position
where it is clear of the interior of the tube to an actuated position
where it projects upwardly into the tube and toward or into the
opening 11.
In addition to the foregoing, the means E includes a suitable stop
and/or orienting means to stop and orient plugs advanced downstream
through the tube in vertical axial alignment with the opening 11
and the unit 20'. In the case illustrated, the stop means is a simple,
vertical web 22 arranged centrally of the tube immediately downstream
of the opening 11 and against which the plugs stop.
A similar web 23 can be provided in the tube upstream of the opening
10 to prevent accidental movement of plugs upstream through the
tube and into the flow line.
The operating means O can vary widely in form and is shown including
a fluid pressure accumulator A, a reservoir K, a fluid pump N' between
the accumulator and reservoir, a four-way valve V connected with
and between the opposite ends of the cylinders of the units 20 and
21 with the accumulator and with the reservoir. The valve is such
that when in a normal position, fluid is directed from one end of
the cylinders of the units 20 and 20' to the reservoir K and fluid
from the accumulator A is directed to the other ends of the cylinders
of the units 20 and 20' to urge and maintain the rams thereof in
their normal, unactuated position and is operable to an actuated
position where the above noted direction of flow is reversed and
the rams of the units 20 and 20' are urged to their actuated positions,
to transfer related plugs as hereinabove described.
The means O next includes a suitable valve actuator or drive means
K operable to intermittently shift or operate the valve V to and
from its actuated position and control means for the means K.
The drive means K can be and is shown as including an electric
linear motor or solenoid unit operable to drive a rack 30 engaging
a pinion 31 on the operating shaft (not shown) of the valve. The
means K is such that it rapidly drives the valve to its actuated
position and remains in that position a suficient period of time
to simultaneously fully actuate the units 20 and 20' of the means
I and E and thereafter returns the valve to its normal position
where the said units are returned to their normal position. The
means E is such that the plugs are moved rapidly and synchronously
into and out of the tube T and in such a manner that little or no
impedence to the flow of fluid in the tube is caused.
The control means, in its simplest form, comprises a plug actuated
switch 40 with a plug engaging operating arm 41 suitably arranged
at and within the downstream end of the duct substantially as shown.
The arm 41 is positioned within the tube so that it is engaged by
the downstream most plug P in the tube T as that plug approaches
aligned position with the opening 11 and so that the switch 40 is
closed and the means K is actuated to effect ejection of the downstream
plug from the tube and simultaneous injection of a plug into the
upstream end of the tube without noticeable or appreciable delay
or interruption of movement of fluid and/or plugs downstream through
the duct.
In addition to the foregoing, the control means includes a counter
and timer means N connected in the circuit between the switch 40
and means K which means counts and times the number of times the
control means is energized to actuate the means K and units 20 and
20'.
In practice, the number of cycles or counts within a fixed period
of time can be presented by a numbered read-out device 50 and the
time can be presented by a clock face 51 provided in the means N.
The means N can further include a suitable graphic recording means
G to record cycling of the means K with respect to time and which
can, if desired, be adjusted and set whereby the rate and/or volume
of fluid flowing through the duct is recorded.
In practice, one or more counting switches 40', similar to the
switch 40 and connected with the means N can be provided in predetermined
longitudinal spaced relationship along the tube T, between the opening
10 and 11. The provision of an additional switch or switches 40',
as above described, increases the number of counts effected by each
plug as it moves downstream in the tube and thereby increases the
accuracy of the meter read-out. Also, by dividing the column of
fluid in the tube T into separated masses by a plurality of plugs,
the intermediate mass or masses serve to buffer or to absorb the
effect the injecting and ejecting of plugs might impose upon the
flow of fluid through the tube T. By counting and timing movement
of the plugs defining the central buffered masses, a smooth, uniform
read-out is assured in most instances.
In practice, the spherical plugs P are preferably light-weight
so that the effect of gravity therein and their mass inertia effect
within the meter is maintained at a minimum. The plugs can be rigid
or can be reasonably flexible, as desired, or as circumstances require.
Referring to FIG. 2 of the drawings, I have shown another form
of meter M' embodying the present invention. The meter M' is similar
in nature to the meter M except the injector and ejector means I'
and E' include plug transporting star wheels W and W' related to
the inlet and outlet openings 10' and 11' at the ends of the tube
T' and duct D'.
The star wheels W and W' are adapted to be intermittently synchronously
rotated a predetermining portion of one revolution by a suitable
drive means E' which is part of the operating means O' of the meter.
The drive means E can, as shown, include a prime mover 50 driving
a shaft 51 which extends longitudinally of the meter and is drivingly
connected with shafts 52 which are provided to rotatably support
the wheels W and W'. The shafts can, as illustrated, be drivingly
connected by means of worm and pinion gears 53 and 54.
In the case illustrated, the wheels W and W' have three arms spaced
120.degree. from each other and are arranged so that they normally
occur clear from interferring engagement in the tube T' and such
that when rotated 120.degree., one arm advances downwardly, forwardly
and thence upwardly into and out of engagement in the tube T' whereby
the wheel W' engages a plug P' in the tube T' adjacent the opening
11' and transfers it through the opening 11' into the duct D' and
the wheel W advances a plug P' in the duct D' adjacent the opening
10' through that opening and into the tube T', as will be abundantly
clear upon viewing FIG. 2 of the drawings.
It will also be apparent that when the plugs P' are advanced from
and into engagement in the tube T' in the manner noted above and
as the wheels W are rotated as noted, the wheel W engages the leading
plug P' at the upstream end of the duct D' and advances that plug
toward the tube T' preparatory to its being advanced, further, into
the tube T', upon the next cycling of the structure. Further, the
wheel W' advances the plugs P' previously removed from engagement
in the tube T' into engagement with their next leading plug P' in
the duct D' and serves to advance the series of plugs P' in the
duct D' upstream therein.
In light of the above noted operation and/or functioning of the
wheel W', it will be apparent that the wheel W could be eliminated
and the wheel W' utilized to advance the plugs into the upstream
end of the tube as the plugs are removed from the downstream end
thereof.
To the above end, and as shown in FIG. 3 of the drawings, the upstream
end of the duct D" need only be provided with a suitable releasable
retaining means R" adjacent the opening 10" to yieldingly
releasably hold the leading plug P" in the duct D" in
said duct until it is forced thereby the advancing series of plugs
in the duct. The means R" can be similar to the means R and
R' shown in FIG. 1 of the drawings or can, as shown in FIG. 3 include
a simple plug-engaging spring-loaded pawl 56.
It is to be noted that in carrying out the forms of the invention
shown in FIGS. 2 and 3 the portions of the wheels W and W' or the
portions of the wheel W' and retainer means R" which do not
occur within the tube T' or T" and the ducts D' or D"
are enclosed within case-like structures related to and communicating
with the tubes and ducts and that the tubes and ducts are suitably
formed or slotted whereby the wheels and/or pawl are free to move
between and within the confines of the tubes, ducts and case-like
structures.
The operating means O' in the form of the invention shown in FIG.
2 of the drawings and which would be provided in that form of the
invention if further modified in accordance with the showing in
FIG. 3 of the drawings is or can be essentially the same in principle
as that provided in FIG. 1 of the drawings, and can include a plug-actuated
cycling switch 40.sup.a at the downstream end of the tube T' to
control the prime mover, a plug actuated counter switch 40.sup.b
between the ends of the tube, counter and timer means N' related
to the switches and which can include a recording means G'.
In the form of the invention shown in FIGS. 4 5 and 6 of the drawings,
I have shown a more compact form of meter M.sup.2 wherein the tube
and duct are in side by side relationship and wherein elongated
plugs P.sup.2 can be advantageously employed.
In this form of the invention, the openings 10.sup.2 and 11.sup.2
are elongated to accommodate the elongated plugs P.sup.2 and can,
as shown, be established by extremely simple chest-like units 60
and 61 which are connected with and between related ends of the
tube T.sup.2 and D.sup.2 and with the sections L.sup.u and L.sup.d
of the flow line and which define transfer chambers between the
said related ends of the tube and duct, the central portions of
which chambers constitute or define the openings 10.sup.2 and 11.sup.2.
The meter M.sup.2 includes means I.sup.2 and E.sup.2 similar to
the means I and E in the first form of the invention and which include
linear prime movers 20.sup.2 and 20.sup.3 in the form of hydraulic
or pneumatic cylinder and ram units or electric solenoids. The means
20.sup.2 is operable to shift and move plugs P.sup.2 delivered to
the upstream end of the duct D.sup.2 into the upstream end of the
tube T.sup.2 and the means 20.sup.3 is operable to shift and move
plugs P.sup.2 delivered to the downstream end of the tube T.sup.2
out of engagement in the tube and into the duct D.sup.2 or into
the chamber defined by the chest 60 preparatory to its being moved
into the duct D.sup.2.
The meter M.sup.2 like the meter M, is provided with retaining
means R.sup.2 and R.sup.3 to releasably hold the plugs at the ends
of the meter in proper operating position during cycling of the
construction.
The means R2 is shown as including a spring-loaded pawl 70 at one
side of the duct 61 and operable to yieldingly releasably hold the
plug P.sup.2 at the upstream end of the construction next to be
introduced into the tube T.sup.2 out of and clear of interfering
engagement in the tube. The means R.sup.3 includes a similar pawl
70' related to the chest 61 and adapted to hold plugs P.sup.2 move
out of engagement in the tube T.sup.2 in alignment with the duct
D.sup.2.
In addition, the meter M.sup.2 includes advancing means A.sup.1
adapted to be operated following each synchronous operation or action
of the means I.sup.2 and E.sup.2 to advance the plug P.sup.2 last
moved from engagement from the tube T.sup.2 by the means E.sup.2
upstream and into engagement in the duct D.sup.2 advance the series
of plugs in the duct D.sup.2 upstream and advance the plug which
is the next to be injected plug, into position and aligned with
the means I.sup.2. The means A' is a simple cylinder and ram unit
or linear electric prime mover mounted at the downstream end of
the chest 61 in axial alignment with the duct D.sup.2 and so that
its linearly shiftable member is shifted in an upstream direction
into and through the chest 61 when the means A' is actuated, to
engage and shift a plug moved in the chest, into alignment with
the duct D.sup.2 upstream into said duct and to thereby move or
advance the plugs P.sup.2 in said duct, upstream, as required.
The control means and/or operating means (not shown) can be essentially
the same as the control and/or operating means in the previously
considered forms of the invention and preferably includes a plug
actuated cycling switch 40.sup.2 at the chest 61 and can, if desired,
include a plug-actuated counter switch 40.sup.3 between the ends
of the tube T.sup.2.
The plugs P.sup.2 are shown as including elongate cylindrical bodies,
longitudinally spaced, annular, radially outwardly projecting, flexible,
fluid pressure actuated, tube engaging sealing flanges at the opposite
ends of the bodies. In practice, the ends of the plug bodies can
be provided with semi-spherical or otherwise suitably shaped ends.
The plugs are preferably hollow structures, in the nature of canisters
and such that they are normally lighter than the fluid they displace
and so that they can be advantageously filled with suitable ballast
whereby their mass is equal or substantially equal to the mass of
fluid they displace and such that their mass affords minimum effect
on the flow of fluid through the tube T.sup.2.
It will be apparent that the fourth and last considered form of
my invention is such that, by suitable reproportioning of the chests
60 and 61 spherical plugs can be advantageously employed, if such
is desired.
Having described typical preferred forms and applications of my
invention, I do not wish to be limited to the specific details herein
set forth but wish to reserve to myself any modifications or variations
which may appear to those skilled in the art and which fall within
the scope of the following claims. |