A turbine-type flow meter is described as a construction enabling
easy access to all parts for cleaning, servicing and replacement.
Specifically, a three piece construction is presented including
end caps housing vanes and a central main body for housing a metering
rotor. The end cap construction provides the bearings for the rotor
and the necessity for flow straighteners is eliminated by pre-selecting
a sufficient distance between the rotor and vanes. Flow is measured
by electrically counting the rotations of the rotor and means are
provided both for sensing gaseous substances and to enable bi-directional
What is claimed is:
1. A flow meter construction for use in producing an electrical
output indicating the amount of flow therein comprising a pair of
symmetrically and axially arranged separating end caps each including
an end cap shell, an axially aligned bearing support assembly and
vanes extending from said assembly to said end cap shell, a main
body between said end caps defining therewithin an inner main body
surface, said main body being axially aligned with said end caps
and said main body surface defining with said end cap shells a continuous,
cylindrical flow meter conduit, a magnetic rotor, supported by said
assemblies and within said main body, whose rotation is responsive
to flow through said flow meter conduit, a magnetic impulse counter
probe for creating a magnetic field in the area of said rotor for
generating pulses proportional to flow through said flow meter conduit
and external clamping means for holding said end caps to said main
body, the distance between said vanes and said rotor being greater
than one-fourth the diameter of said flow meter conduit.
2. A flow meter construction according to claim 1 wherein said
main body further defines first and second openings through said
surface, an air probe extending through said first opening into
said conduit for controlling the production of said electrical output
and a trim vane extending through said second opening on the opposite
side axially of said magnetic impulse counter probe from said air
probe, attached to said counter probe and arranged to produce directional
turbulence within said conduit and to enable bi-directional flow.
3. A flow meter construction according to claim 1 wherein said
assembly removably supports said magnetic rotor.
4. A flow meter construction according to claim 1 wherein said
end caps and said main body together define outwardly directed protrusions
for mating with said external clamping means.
5. A flow meter construction according to claim 1 wherein sanitary
seals are between said end caps and said main body.
This invention relates primarily to measuring devices and more
particularly to flow measuring device of the turbine-type, particularly
useful in applications requiring sanitary and accessible construction.
Presently used flow measuring devices are basically of a one-piece
construction whereby a set of vanes straddle a measuring rotor and
are clipped into place such as by internal snap rings held in position
within the unitary body of the meter. The snap rings engage recesses
machined into the body. A separate flow straightener is coupled
with the main body of the meter so that the liquid being measured
enters the main body in a predictable flow pattern.
For sanitary applications, the presently used one-piece construction
with coupled flow straightener is unsatisfactory because of the
tendency of contamination to occur where the flow straightener is
coupled to the main body and where the internal snap rings holding
the vanes engage recesses machined in the main body. Furthermore,
the one-piece construction provides a problem of accessibility to
the bearings, vanes and rotor for the purposes of cleaning and replacement.
Also, such presently used one-piece constructions with attached
flow straightener enable uni-directional use only.
Accordingly, it is an object of the present invention to provide
a construction for a flow meter of the turbine-type which enables
easy access to parts for cleaning, servicing and replacement.
A further and more specific object of the present invention is
to provide a multi-piece device to enable easy access to all parts
A still further object is to eliminate the need for a flow straightener
in a flow metering device and to mount the vanes for the meter in
such a way as to enable cleaning and servicing in sanitary applications.
Another object of the present invention is to provide a bi-directional
flow capability for a flow meter.
These and other objects of the present invention are provided in
a flow meter construction of the turbine-type which includes three
general parts for enabling easy access for cleaning, servicing and
replacement. By way of background, a flow meter of the turbine-type
operates with a rotor of magnetic material spinning in response
to the flow therethrough of a liquid. A magnetic field is created
in the area of the rotor so that as the rotor spins it passes through
the field and thereby generates a pulse which can be counted and
which relates to the flow of liquid passing the rotor. The flow
meter of the present invention includes identical end caps straddling
a main body, with the rotor being supported by the end caps for
rotation within the main body. Vanes are welded in the end caps
at a sufficient distance from the rotor so that flow straightening
is accomplished prior to the liquid reaching the rotor. External
clamps couple the end caps to the main body and bearing support
assemblies are located centrally of the vanes for providing thrust
and carrier bearings for the rotor turbine shafts extending axially
of the rotor.
The main body defines an outer cylindrical surface centrally through
which extends a magnetic impulse counter probe for sensing the rotations
of the rotor as the fluid passes therethrough. Also extending through
the main body, either forward or backward of the rotor in terms
of flow, is an air probe, which senses the conductivity of the fluid
passing through the device in order to enable or impede the magnetic
impulse counter probe circuit, so that fluid is distinguishible
from gas in the measuring process.
A trim vane is inserted through the main body outer surface to
create directional turbulence onto the rotor and thereby enable
bi-directional calibration of the device.
The above brief description, as well as further objects features
and advantages of the present invention, will be more fully appreciated
by reference to the following detailed description of a presently
preferred, but nonetheless illustrative embodiment in accordance
with the invention, when taken in conjunction with the accompanying
FIG. 1 is an isometric, disassembled view of a flow meter according
to the present invention, showing particularly the arrangement of
parts thereof and a construction enabling easy access to parts for
cleaning, repair and/or replacement thereof and further illustrating
the bi-directional flow capability of the device;
FIG. 2 is a side assembly view, shown partly in section and showing
particularly the magnetic impulse counter probe;
FIG. 3 is a back, partly sectional view of the device of FIG. 2
taken along the line 3--3 thereof and showing particularly the air
probe and the external clamp holding the end cap to the main body;
FIG. 4 is a back, partly sectional view taken along the line 4--4
of FIG. 2 and showing particularly the trim vane of the device;
FIG. 5 is a side sectional view taken along the line 5--5 of FIG.
4 and showing particularly the trim vane blade shape and construction.
Referring to the drawings, and in particular FIG. 1 a flow meter
construction is shown in disassembled view as including end caps
10 of generally cylindrical shape and supporting axially thereof
bearing support assemblies 12. Bearing support assemblies 12 are
mounted by means of vanes 14 projecting therefrom and welded on
the internal surface 16 defined by the end caps. The internally
projecting ends of bearing support assemblies 12 mount thrust bearings
18 (FIG. 2) and carrier bearings 20 for supporting rotor 22 as will
hereinafter be described.
Main body 24 of the flow meter is also generally of a cylindrical
shape and defines there within a precisely cylindrical surface 26.
Rotor 22 is positioned centrally and axially of main body 24 with
turbine shafts 28 projectng outwardly and axially thereof for mounting
within the bearing supports 18 20 previously described. Sanitary
seals 30 effectively seal the mating of main body 24 to end caps
10 so that a continuous, internal cylindrical surface is presented
to the material flowing through the device.
Vanes 14 are positioned with respect to the leading edges of the
rotor 22 so that there is a distance therebetween of at least one-quarter
the internal diameter of the device in order to eliminate the need
for flow straighteners, whose function is instead performed by four
or more vanes 14.
Main body 24 defines openings 32 34 36 (FIG. 4) therethrough
to enable mounting, respectively of magnetic impulse counter probe
38 air probe 40 and trim vane 42. Specifically, magnetic impulse
counter probe, generally designated 38 mounts a magnetic probe 39
and circuit 41 (FIG. 2) whose function it is to magnetically sense
the rotations of rotor 22 and to cause an electrical output proportional
to such rotations at connectors 43.
The air probe, generally designated 40 includes projectng probe
device 44 which actually inserts through the side wall of main body
24 and into the flow path of the fluid being measured. Since it
is well known that liquids always include salts making conductivity
higher, if it is desired to measure liquids only, air probe 40 senses
conductivity and by electrical coupling to magnetic impulse counter
probe 38 controls whether or not a measurement is made. For instance,
if air only is flowing through the device, air probe 40 will sense
the lower conductivity and electrically prevent a measurement by
means of an output from magnetic impulse counter probe 38. As a
further example, if the device of the present invention were used
to measure the amount of tomato juice being processed, air probe
40 would prevent the continuation of counting by magnetic impulse
counter probe 38 after the completion of flow by the processed tomato
juice when only air would be going through the device.
The trim vane, generally designated 42 is positioned on the opposite
side of the rotor to the air probe 40 if fitted. The trim vane is
adjustable to create directional turbulence to increase or decrease
the rotor speed and to give identical rate of rotation per unit
volume flow, as with the trip vane on the downstream side. Trim
vane blade 46 of trim vane 42 actually inserts to the path of flow
within main body 24 and is adjustable by trial and error to match
the turbulence caused by air probe 40 so that the device may be
used bi-directionally with either end cap as the input structure
for the liquid being measured. For instance, if air probe 40 is
positioned after rotor 22 when liquid is flowing in direction 48
there will be no turbulence imparted to the liquid. However, if
direction 48 is reversed for the flow, there will be such a turbulence.
In order to use the device bi-directionally, if the direction of
flow is opposite to direction 48 when magnetic impulse counter probe
38 is calibrated, bi-directional flow will only be enabled if an
equal and opposite turbulence is caused when the liquid flows in
direction 48. Accordingly, trim vane 42 with trim vane blade 46
projecting into the path of flow is used to create the same turbulence
when flow is in direction 48 as was present when calibration took
place with flow in a direction opposite to direction 48 as caused
by projecting probe device 44. In other words, assume a flow direction
opposite to that designated by arrow 48. With air probe 40 in position,
30000 pulses is the output from magnetic impulse counter probe
38 for 100 gallons of liquid during the calibration procedure. Flow
is then reversed to direction 48 and the angle of trim vane blade
46 is adjusted until magnetic impulse counter probe 38 puts out
30000 pulses for 100 gallons (300 pulses per gallon). After such
a calibration procedure, flow is enabled in either direction with
the same turbulence effect and attendant accurate measurement in
Referring to the other drawings, the present invention construction
is shown assembled with sanitary seals 30 in place. It should be
particularly noted that the internal flow path is defined by a continuous
cylindrical surface 16 26. The main body 24 and end caps 10 are
formed of non-magnetic stainless steel so as not to interfere with
the function of magnetic impulse counter probe 38. The coupling
of main body 24 to end caps 10 produces protrusions 50 on the outside
surface of the device, over which clamping assemblies 52 conform
in order to seal the mating of main body 24 to end caps 10 as is
shown particularly in FIGS. 2 and 3.
Clamping assemblies 52 include clamp handle 54 clamp bands 56
hinge 58 and link 60 all operable by means well known.
FIGS. 4 and 5 particularly show the calibration adjustment feature
of trim vane 42 whereby trim vane blade 46 is angularly adjusted
simply by inserting a screw driver or the like to slot 62 defined
by trim vane 42.
In order to more clearly describe apparatus according to the present
invention, and the features thereof, a sequence of the operations
of the device will now be set forth. Firstly, assembly of the device
takes place by removably mounting rotor 22 to bearing support assembly
12 on one of the end caps 10. This is accomplished by merely inserting
sanitary seal 30 within end cap 10 and turbine shaft 28 into carrier
bearing 20. End cap 10 with rotor 22 thus mounted, is inserted
to main body 24. The other end cap is then likewise mated when main
body 24 and clamps 52 operated to fix the three-piece construction.
Magnetic impulse counter probe 38 is threadedly inserted to a position
within the wall of main body 24 so that it is centrally positioned
between the ends of main body 24 adjacent the rotor position. Air
probe 40 is threadedly inserted so that projecting probe device
44 extends to the flow path within the inner wall 26 of main body
24. Trim vane 42 is likewise threadedly inserted so that trim vane
blade 46 extends to within the inner wall 26 of main body 24. The
device is then coupled to a pipeline or the like through which liquid
is caused to flow in a direction opposite to that designated by
Calibration is performed by causing a known quantity of liquid
to flow through the device and counting the pulse output of magnetic
impulse counter probe 38. The same quantity of liquid is then caused
to flow in direction 48 and the angle of trim vane blade 46 is adjusted
so that an equal number of pulses per gallon of liquid is counted
by means of magnetic impulse counter probe 38.
The device is now ready for flow in either direction with air probe
40 terminating the output of magnetic impulse counter probe 38 whenever
air or another gas is sensed.
Cleaning, repair or parts replacement is conveniently enabled by
reversing the assembly process and the smooth, continuous internal
flow path prevents contamination from building up within the device,
for instance, in a liquid food processing use for the device.
Furthermore, the construction presented by this invention eliminates
the need for a separate flow straightener and generally contributes
to an efficient, maintainable and yet simple device with flexible
convenient usage capability.