Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to fluid flow meters.
I~itherto, the many flui~ flow metering requirements
have resulte~ in numerous different types of flow meters. The
operational principles of flow me-ters vary a lot; listed here
are a few classes: differentia1 pressure flow meters, mass
flow meters, area flow meters, electromagnetic flow meters,
positive displacemen-t flow meters, and, open channel flow
meters. All of these have specific areas of application but
have also their limitationsq as for example: some do not ope-
rate in reverse flow conditions; some must be mounted only inone position; some do not work well with soily or opaque
liquids; some require individual calibration; some are not
easily convertable to digital display output nor remote dis-
play; some must have see-through tubes, and; some may become
damaged by pressure variations or by changes in physical state
of the fluid being measured.
One aspect appears to be common to a great many
flow meters: the price - they are quite expensive. In many
cases this is the result of the intricate nature of the device
and the resultant high degree of accuracy required in manufac-
turing the component parts. In other cases individual calib-
ration is a necessary requirement leading to the high price.
The idea of the present invention is to have as a
moving part a ball and as a housing material having groves and
holes, through which fluid may flow unobstructively, thus
causing the ball to follow the total volumetric velocity of
the fluid without leaving the housing body. This permits -the
revolutions to be counted, and from this volume, flow rate and
other data can be computed, indicated, recorded and controlled.
It is an object of the present invention to accomp-
lish accurate measurement of fluid flow in a way that allows
inexpensive fabrication of the device through mass production.
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Other objects of this invention are to make the
device: respond well to changes in flow over a wide range of
flow rates, especially in the laminar region; to handle pure
fluids as well as true solutions, colloidial dispersions and
suspensions of fluids; handle high viscosity liquids and non-
Newtonian fluids; unsusciptible to changes in viscosity or
temperature of the liquid; offer little resistance to fluid
flow; unaffected from hammer effect; and capable of measur-
~ ing pulsating flow.
; 10 Further objects of this invention are to provide
; a device which is simple in design, construction and opera-
tion; offers ease of installation and maintenance; and; has
; long service life.
In this invention the ball in the housing will
follow the fluid flow at a velocity very close to the velo-
city of the fluid. This invention may be classed as a posi-
tive displacement flow meter and an area-velocity inte-
grating type flow meter as it has the characteristics Gf
both. Making reference here to other similar looking
devices having a spinning ball and two orifices on the
outer surface of the toroid, and used as flow indicators,
the basic difference to these is in the arrangement of the
orifices, explained later, which makes these flow indicator
devices perform differently and not part of the positive
displacement category.
For the fluid there are one inlet and one outlet
orifice located so that when the fluid entering at the
inlet orifice has made almost one full round within its
circular passageway, it will exit at the outlet orifice
located almost opposite the inlet orifice. The ball will
otherwise follow the mass of the fluid but, due to the
shape and size of the outlet orifice, will not exit but
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travels past the boundary line between the incorning and
outgoing fluids, only to start another cycle in the device.
The pushing force of the fluid is continuous, without
interruptions, between the inlet and outlet orifices.
The toroidal passageway in the housing is as
round and circular in shape with as smooth a surface as
can be manufactured without extra effor-t. The ball is only
slightly smaller than its passageway to allow free travel~
touching the wall of the passageway only at one point, as
a rule~ or occasionally, at two points on locations where
an orifice is located, or at no point at all.
The inlet and outlet orifices in the passageway
carry through the housing to the outside surface where
connections to pipe, hose, tube or other fluid carrying
enclosure or fitting can be made. A good direction to the
holes thus formed is close to the line which is 17 degrees
away from the direction of the tangent to the centre line
of the toroidal passageway, the 17 degree-line being on the
perpendicular plane to the plane defined by thetoroid's centre
line and the tangent to the centre line. The above
direction minimizes friction and turbulence; however~
deviations from said direction up to 45 degrees to the plane
defined by the centre line do not make the device in-
operative. The two orifices, formed where the holes from the
exterior connection means meet the toroidal passageway~ are
on the opposite sides on the passageway but slightly off,
allowing the fluid to flow easily into and out of the
passageway.
The most prevelent application of this invention
is envisioned as that of measuring flow rates of liquids in
situations where digital read-out is required, or, where
signals~ directly proportional in frequency to the flow rate,
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carry the lnformation to the processor. To the large family
of different types of flow meters this invention is a new-
comer, suitable for many -uses. For example~ this invention
can be used when an inexpensive device with electronic pulse
output, together with a signal processor, is required, e.g.
in aircraft for measurement of gasoline consumption. In
automobiles and boats and ships this invention can provide
similar information.
In any watercraft this invention, when installed
to read water speed, can measure the speed of the vessel,
the distance travelled, etc.
In industrial applications the flow rate of many
types of liquids can be measured because the invention can
be made of metals or plastics. Monitoring, batching and
totalizing of volumes of liquids as part of process control
is just a matter of selecting the appropriate signal pro-
cessor.
From the foregoing it should be apparent that
the application of the present invention overcomes numerous
objections heretofore encumbering the measuring of fluid
flow, one important feature being the freedom of mounting
in any position.
In the following explanatory description of this
invention reference is made to the accompanying drawings, to
wit: -
FIG. 1 is an isometric view, half-way transparent,
of the fluid flow metering device.
FIG. 2 is a sectional view of the fluid f`low
metering device taken in the plane indicated by line II-
II of FIG. 3, and showing the location of the toroidal ori-
fices in relation to each other and to the external connec-
tion means. This view also shows the male~type external
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connection means and the clamp-type fastening means of the
housing halves.
FIG. 3 is a sectional view of the fluid flow
metering device taken in the plane indicated by line III-
III of FIG. 2, and showing the ideal location of the inlet
orifice in relation to the external connection means and
to the toroidal passageway. This view also shows the male-
type input connection means and the screw-nut type
fastening means of the housing halves. m e sectional view
taken in the opposite direction of the plane III-III is
identical to this one.
It is considered that the most advantageous
application of the idea embodied in this invention is to be
found in a fluid flow metering device constructed as
follows:
The passageway 1, shaped as a toroid, is formed
by two housing halves 2a and 2b,-each having a grove of
semicircular section, when the housing halves 2a and 2b are
fastened together. The housing halves 2a and 2b also contain
the orifices 3 and 4, leading, within the housing halves 2a
and 2b, to the inlet and outlet connection means, male 5a
and 6a, or female 5b and 6b.
In operation the flow of fluid through the device
can be in either direction, and the use in this specifi-
cation of terms 'inlet' and 'outlet' is only for clarity of
description. Also, the connecting means may be male, female,
or other as per need.
The ball 7 enclosed within the passageway 1 is
the only moving component. The diameter of the ball 7 is
slightly less than the diameter of the passageway 1.
The inlet orifice 3 and the outlet orifice ~ in
the passageway 1 are sized, shaped and located in such a
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manner that the fluid flowing through the passageway 1 willmove with little friction and will direct its force in the
direction of its travel.
The size of the orifices 3 and 4 is close -to the
cross-sectional area of the inlet and outlet connection
means 5a or 5b and 6a or 6b as well as to the passageway 1.
This reduces the minor losses due to acceleration and de-
celeration of the fluid, and thus the overall pressure drop
across the fluid flow meter, to the minimum.
The shape of the orifices 3 and 4 is, preferably,
close to that of a droplet. When fluid enters the passageway
1 at an angle less than 45 degrees this shape directs the
centre of mass of the fluid towards the centre line ~ of
the passageway 1.
The location of the orifices 3 and 4, when viewed
in the direction of the line l, is such that the droplet
heads are touching but not overlapping each other~ and the
two holes connecting the orifices 3 and 4 with the inlet and
outlet connection means 5a or 5b and 6a or 6b are off by one
hole width as shown in FIG. 2. At the location between the
orifices 3 and 4 on the line l the incoming fluid meets and
directs out the fluid just as it is about to complete a
revolution in the passageway 1. Thus all fluid enters the
passageway 1 without shortcutting to the opposite outlet
orifice 4, and, consecuently, the ba]l has the least dis-
tance to clear without propulsion before starting a new
round.
The means of fastening the housing halves 2a and
2b are: 8a is a typical rivet, screw, screw-nut combination,
or similar; 8b is a clamp outside the housing 2, and; 8c is
a permanent bond. Fastening means 8a and 8b require the
gland 9 and seal 10 outside the passageway 1 to make a
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fluidtight joint.
The pick-off means 11 is loca-ted perpendicular to
the passageway 1 and may operate on the optoelectronic prin-
ciple, if the housing halves 2a or 2b, or both or part of
them are transparent; or, may operate on the proximity
sensing principle, e.g. inductive, capacitive, or magnetic,
if the housing halves 2a and 2b are opaque.
The signal processor 12 is equipped with proper
read-out display and is connected to the pick-off means 11.
All materials embracing the fluid are impervious
and joined to form a fluidtight enclosure. Either thermo-
plastics or thermosetting plastics can be utilized for this
purpose, as can other materials, such as metals and glass.
Selecting appropriate materials for the housing halves 2a
and 2b and the ball 7 involves taking into consideration
the effect the fluid will have on the materials and the
requirements of the pick-off means, and the workability of
the materials. Selecting proper material for the ball 7
also involves choosing a material with low specific gravity,
or, if a material with high specific gravity is chosen,
e.g. a ferromagnetic plastic, then the ball 7 would have to
be hollow to reduce its weight.
I have discovered that devices~ being otherwise
similar but having holes at different angles~ i.e. angles
formed by the li~e l and the plane of the centre circle of
the toroid, perform differently. Other factors being same,
devices having different size toroids, or different size
passageways, also perform slightly differently. In theory,
viscosity of the fluid being measured has the Aominating
effect on the above performance; however, in practice, with
proper dimensioning~ the effect of viscosity on this inven-
tion is less than on most other types of flow meters.
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