Abstrict An impact flow meter for measuring a horizontal impact force produced
by falling material has a frame and a sensing plate having a front
surface and a spaced opposite back surface. A hanging device hangs
the plate vertically on the frame thereby preventing material from
adhering to the plate. A flow guide is mounted in the frame in front
of the front surface of the plate at an inclination with the vertical
for directing the falling material to the front surface of the plate
whereby the plate is struck by the material. An impact force detector
couples the back surface of the plate to the frame for measuring
the horizontal impact force of the material.
Claims What is claimed is:
1. An impact flow meter for measuring a horizontal impact force
produced by falling material, said flow meter comprising:
a frame;
a sensing plate having a front surface and a spaced opposite back
surface;
hanging means hanging said plate substantially vertically on said
frame thereby preventing material from adhering to said plate;
a flow guide mounted in the frame in front of the front surface
of said plate at an inclination with the vertical for directing
the falling material to said front surface of said plate whereby
said plate is struck by said material; and
an impact force detector coupling the back surface of said plate
to said frame for measuring the horizontal impact force of said
material.
2. An impact flow meter as claimed in claim 1 wherein said hanging
means comprises strip springs.
3. An impact flow meter as claimed in claim 1 wherein said impact
force detector comprises load cells.
4. An impact flow meter as claimed in claim 1 wherein said sensing
plate has a top edge and a spaced opposite bottom edge, and further
comprising a counterweight mounted on said plate at said top edge
thereof for counteracting any torque produced by said plate.
5. An impact flow meter as claimed in claim 4 wherein said top
and bottom edges of said sensing plate are substantially parallel.
6. An impact flow meter as claimed in claim 1 further comprising
an amplifier for amplifying the force of impact of said material
on said sensing plate, said amplifier comprising
a beam affixed to, and extending outwardly from, said back surface
of said plate, said beam having a free end spaced from said plate,
a lever having a top edge and a spaced opposite bottom edge,
first connecting means connecting said lever to the free end of
said beam in the area of the top edge of said lever, and
second connecting means connecting said lever to said frame in
the area of the bottom edge of said lever, said impact force detector
being affixed to said frame and coupled to said lever intermediate
said top and bottom edges of said lever.
7. An impact flow meter as claimed in claim 6 wherein said lever
is in spaced substantially parallel relation with said sensing plate.
8. An impact flow meter as claimed in claim 6 wherein each of
said first and second connecting means comprises a wire.
9. An impact flow meter as claimed in claim 8 wherein each said
wire constitutes a piano wire.
10. An impact flow meter as claimed in claim 1 wherein said front
and back surfaces of said sensing plate are substantially parallel.
Description BACKGROUND OF THE INVENTION
The present invention relates to an impact flow meter. More particularly,
the invention relates to an impact flow meter for measuring a horizontal
impact force produced by falling material. The material may constitute
powder and/or bulk solids.
In known types of impact flow meters, the weight of the sensing
plate is many times, as much as one hundred times, the impact force.
The great weight of the sensing plate is required for its necessary
great structural strength and results in friction during movement
thereof under the impact of falling material. This is a disadvantage,
since the sensing plate should move as closely to frictionless as
possible. Furthermore, powder falling onto the sensing plate may
adhere to it, since said plate is not vertically mounted. Also,
if the flow meter is not mounted at a correct and proper level,
its zero point shifts during operation and results in an erroneous
measurement of the impact force.
SUMMARY OF THE INVENTION
The principal object of the invention is to provide an impact flow
meter of simple structure for measuring a horizontal impact force
produced by falling material.
An object of the invention is to provide an impact flow meter for
measuring a horizontal impact force produced by falling material,
which meter has a sensing plate mounted in a manner which prevents
material from adhering thereto.
Another object of the invention is to provide an impact flow meter
for measuring a horizontal impact force produced by falling material,
which flow meter has a sensing plate which is hung substantially
vertically and in a manner whereby any movement of said plate is
substantially frictionless.
Still another object of the invention is to provide an impact flow
meter for measuring a horizontal impact force produced by falling
material, which flow meter includes a sensing plate of great structural
strength mounted in a manner whereby its movement under the impact
of falling material is substantially frictionless.
Yet another object of the invention is to provide an impact flow
meter for measuring a horizontal impact force produced by falling
material, which flow meter functions efficiently, effectively and
reliably to accurately measure a horizontal impact force.
Another object of the invention is to provide an impact flow meter
for measuring a horizontal impact force produced by falling material,
which flow meter includes an amplifier for amplifying the force
of impact of falling material on the sensing plate efficiently,
effectively and reliably.
Still another object of the invention is to provide an impact flow
meter for measuring a horizontal impact force produced by falling
material, which flow meter counteracts a zero shift caused by operation
while mounted at an incorrect level, thereby eliminating impact
force measurement error which results from operation while mounted
at an incorrect level.
Yet another object of the invention is to provide an impact flow
meter for measuring a horizontal impact force produced by falling
material, which flow meter requires considerably less maintenance
than known similar flow meters.
In accordance with the invention, the impact flow meter for measuring
a horizontal impact force produced by falling material comprises
a frame and a sensing plate having a front surface and a spaced
opposite back surface. A hanging device hangs the plate substantially
vertically on the frame thereby preventing material from adhering
to the plate. A flow guide is mounted in the frame in front of the
front surface of the plate at an inclination with the vertical for
directing the falling material to the front surface of the plate
whereby the plate is struck by the material. An impact force detector
couples the back surface of the plate to the frame for measuring
the horizontal impact force of the material.
The hanging device comprises strip springs.
The impact force detector comprises load cells.
The sensing plate has a top edge and a spaced opposite bottom edge.
A counterweight is mounted on the plate at the top edge thereof
for counteracting any torque produced by the plate.
An amplifier amplifies the force of impact of the material on the
sensing plate. The amplifier comprises a beam affixed to, and extending
outwardly from, the back surface of the plate. The beam has a free
end spaced from the plate. A lever has a top edge and a spaced opposite
bottom edge. A first connector connects the lever to the free end
of the beam in the area of the top edge of the lever. A second connector
connects the lever to the frame in the area of the bottom edge of
the lever. The impact force detector is affixed to the frame and
coupled to the lever intermediate the top and bottom edges of the
lever.
The front and back surfaces of the sensing plate are substantially
parallel.
The top and bottom edges of the sensing plate are substantially
parallel.
The lever is in spaced substantially parallel relation with the
sensing plate.
Each of the first and second connectors comprises a wire. Each
wire constitutes a piano wire.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is had to
the following description, taken in connection with the accompanying
drawings, in which:
FIG. 1 is a schematic diagram of an embodiment of an impact flow
meter of the prior art for measuring a horizontal impact force produced
by falling material;
FIG. 2 is a schematic diagram, viewed from a side, of an embodiment
of the impact flow meter of the invention for measuring a horizontal
impact force produced by falling material; and
FIG. 3 is a schematic diagram, on an enlarged scale, viewed from
a side, of another embodiment of the impact flow meter of FIG. 2.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows an embodiment of an impact flow meter of the prior
art for measuring a horizontal impact force produced by falling
material. In the known embodiment of FIG. 1 a sensing plate 1 and
an impact force detector 4 are supported by the same pivot 12. The
impact force detector 4 is of any suitable known type and functions
in a known manner. The pivot 12 must be of great structural strength
and must rotate as close to frictionless as possible, in order to
support the heavy sensing plate 1 and to permit accurate function
of the flow meter. The weight of the sensing plate 1 is usually
about one hundred times greater than the impact force of the material
5 falling on said plate.
Since the sensing plate 1 is mounted at an angle with the vertical,
the material 5 tends to adhere to said sensing plate, when it is
powder, and especially when it is sticky powder. The adherence of
powder to the sensing plate 1 is a problem since it distorts the
measurement of the impact force.
The impact flow meter of the invention overcomes the shortcomings
of the flow meters of the prior art. As shown in FIGS. 2 and 3
the naturally falling material 5 to be measured strikes a flow guide
6 which is mounted in a frame 2 at an inclination with the vertical
and directs the falling material to the front surface 1A of the
sensing plate 1. The sensing plate 1 has the front surface 1A and
a spaced opposite back surface 1B, which are in substantially parallel
relation. The sensing plate 1 also has a top edge 1C and a spaced
opposite bottom edge 1D in substantially parallel relation (FIGS.
2 and 3). The sensing plate 1 is hung substantially vertically on
the frame 2 and is positioned in front of the flow guide 6 whereby
the front surface 1A of said plate is struck by the material 5
as shown in FIGS. 2 and 3.
Since the sensing plate 1 is hung substantially vertically via
strip springs 3 the material 5 is prevented from adhering to said
plate. An impact force detector 4 such as, for example, load cells,
couples the back surface 1B of the sensing plate 1 to the frame
2 and measures the horizontal impact force of the material 5 in
the usual manner, producing an electrical signal corresponding to
such impact force and thereby to the flow of said material.
The impact flow meter of the invention, as shown in FIGS. 2 and
3 thus replaces the pivot 12 of the prior art flow meter with the
strip springs 3 thereby considerably reducing the friction of movement
of the sensing plate 1 and eliminating the adherence of material
to said plate. Even if the sensing plate 1 is large and heavy, its
movement under impact is essentially frictionless in the embodiments
of FIGS. 2 and 3.
If the level of the flow meter shifts during operation of said
flow meter, the zero point of said flow meter shifts and results
in error in the measurement result of the horizontal impact force.
The zero shift is eliminated by a counterweight 7 mounted on the
sensing plate 1 at the top edge 1C thereof, as shown in FIGS. 2
and 3. The counterweight 7 functions to counteract any torque or
momentum produced by the sensing plate 1 about the strip springs
3. Since the level of installation of the flow meter is almost always
incorrect, the counterweight 7 is of great importance in overcoming
the adverse effects thereof.
The impact force of the material 5 on the sensing plate 1 is quite
small, compared with the flow rate of said material and is sometimes
too small for accurate detection by the impact force detector 4.
Thus, for example, the material 5 flowing at one ton per hour produces
only about thirty to fifty grams of horizontal impact force on the
sensing plate 1. It is thus expedient to amplify the force of impact
of the material 5 on the sensing plate 1.
The embodiment of FIG. 3 of the flow meter of the invention includes
an amplifier for amplifying the force of impact of the material
5 on the sensing plate 1. The amplifier comprises a beam 8 affixed
to and extending outwardly from, the back surface 1B of the plate
1. The beam 8 has a free end 8A spaced from the plate 1. A first
connector 9 which is preferably a piano wire, connects a lever
10 to the free end 8A of the beam 8 in the area of the top edge
10A of said lever. A second connector 11 which is preferably a
piano wire, connects the lever 10 to the frame 2 in the area of
a bottom edge 10B of said lever.
The lever 10 is in spaced substantially parallel relation with
the sensing plate 1. The impact force detector 4 is affixed to the
frame and coupled to the lever 10 intermediate the top and bottom
edges 10A and 10B of said lever.
The horizontal impact force F.sub.o produced on the sensing plate
1 is amplified to a force F by the amplifier. The force F is measured
by the impact force detector 4 and equals
wherein, as shown in FIG. 3 L.sub.1 is the distance between the
strip springs 3 and the point at which the horizontal impact force
F.sub.0 acts on the lever 10 L.sub.2 is the distance between the
strip springs 3 and the point at which the horizontal impact force
F.sub.o acts on the sensing plate 1 L.sub.3 is the distance between
the point at which the horizontal impact force F.sub.o acts on the
lever 10 and the impact force detector 4 and L.sub.4 is the distance
between the impact force detector 4 and the point at which the lever
10 is affixed to the frame 2.
The invention is by no means restricted to the aforementioned details
which are described only as examples; they may vary within the framework
of the invention, as defined in the following claims.
It will thus be seen that the objects set forth above, among those
made apparent from the preceding description, are efficiently attained
and, since certain changes may be made in the above constructions
without departing from the spirit and scope of the invention, it
is intended that all matter contained in the above description or
shown in the accompanying drawings shall be interpreted as illustrative
and not in a limiting sense.
It is also to be understood that the following claims are intended
to cover all of the generic and specific features of the invention
herein described, and all statements of the scope of the invention
which, as a matter of language, might be said to fall therebetween.
|