Abstrict A flow meter comprises a housing with a tube, a floater inside
the tube, and a permanent magnet embracing the housing. The volume
of a fluid being passed through the tube defines the height of the
floater position in the tube. The floater is equipped with a rotation
coil and bulb connected thereto. Rotating the floater in the magnetic
field of the permanent magnet under the influence of a fluid induces
a voltage in the coil, and the bulb is turned on making reading
volume values easier and more convenient.
Claims What is claimed is:
1. A self-illuminating floater for a flow meter of the type comprising
a housing including a tube, a hollow of said tube having a cross-section
area increasing from minimal at a lower end of said tube to a maximal
at an upper end of said tube, and a permanent magnet extending along
said housing and having a U-shape profile, said housing being placed
into said U-shape profile of said permanent magnet, said floater
comprising an electromagnetically operated source of light, whereby
said source of light is on upon rotating said floater in a magnetic
field of said permanent magnet under an influence of a fluid being
passed through said tube.
2. The self-illuminating floater as claimed in claim 1 wherein
said source of light comprises a rotation coil and bulb, ends of
said rotation coil being connected to said bulb.
3. The self-illuminating floater as claimed in claim 2 further
comprising a head and a body, said body including said rotation
coil, said head comprising said bulb.
4. The self-illuminating floater as claimed in claim 3 wherein
said head is made with slits on its surface, to thereby impart a
rotational force to said floater under the influence of said fluid
being passed through said tube for the purpose of centering and
stabilizing said floater.
5. The self-illuminating floater as claimed in claim 1 wherein
said tube is made translucent and marked with a graduated scale
such that the exact position of said floater heightwise within said
tube correlated with flow rate of said fluid is visibly attributed
to a respective reading in accordance with formula
where Q is the volume of said fluid flowing through the flow meter
per a time unit, A is the area, through which said fluid flows,
and V is the velocity, at which said fluid flows through said area
A.
6. A self-illuminating floater for a flow meter of the type comprising
a housing including a tube and a permanent magnet extending along
said housing and having a U-shape profile, said housing being placed
into said U-shape profile of said permanent magnet, said floater
comprising a body and a head, said body comprising a rotation coil,
said head comprising a bulb, ends of said rotation coil being connected
to said bulb, said head being made with slits on its surface, to
thereby impart a rotational force to said floater for the purpose
of centering and stabilizing said floater under the influence of
said fluid being passed through said tube, whereby said bulb is
on upon rotating said floater in a magnetic field of said permanent
magnet under an influence of a fluid being passed through said tube.
7. The self-illuminating floater as claimed in claim 6 wherein
a hollow of said tube has a cross-section area increasing from minimal
at a lower end of said tube to a maximal at a upper end of said
tube.
8. The self-illuminating floater as claimed in claim 6 wherein
said tube is made translucent and marked with a graduated scale
such that the exact position of said floater heightwise within said
tube correlated with flow rate of said fluid is visibly attributed
to a respective reading in accordance with formula
where Q is the volume of said fluid flowing through the flow meter
per a time unit, A is the area, through which said fluid flows,
and V is the velocity, at which said fluid flows through said area
A.
9. A flow meter comprising a housing including a tube with a floater
located inside the tube and a permanent magnet extending along said
housing and having a U-shape profile, said housing being placed
into said U-shape profile of said permanent magnet, said floater
comprising an electromagnetically operated source of light, whereby
said source of light is on upon rotating said floater in a magnetic
field of said permanent magnet under an influence of a fluid being
passed through said tube.
10. The flow meter as claimed in claim 9 wherein a hollow of said
tube has a cross-section area increasing from minimal at a lower
end of said tube to a maximal at an upper end of said tube.
11. The flow meter as claimed in claim 9 wherein said tube is
made translucent and marked with a graduated scale such that the
exact position of said floater heightwise within said tube correlated
with flow rate of said fluid is visibly attributed to a respective
reading in accordance with formula
where Q is the volume of said fluid flowing through the flow meter
per a time unit, A is the area, through which said fluid flows,
and V is the velocity, at which said fluid flows through said area
A.
12. The flow meter as claimed in claim 9 wherein said source of
light comprises a rotation coil and bulb, ends of said rotation
coil being connected to said bulb.
13. The flow meter as claimed in claim 12 wherein said floater
comprises a head and a body, said body including said rotation coil,
said head comprising said bulb.
14. The flow meter as claimed in claim 9 wherein said head is
made with slits on its surface, to thereby impart a rotational force
to said floater under the influence of said fluid being passed through
said tube for the purpose of centering and stabilizing said floater.
15. A flow meter comprising a housing including a tube with a floater
located inside the tube and a permanent magnet extending along said
housing and having a U-shape profile, said housing being placed
into said U-shape profile of said permanent magnet, said floater
comprising an electromagnetically operated source of light and being
made with slits on its surface, to thereby impart a rotational force
to said floater, whereby said source of light is on upon rotating
said floater in a magnetic field of said permanent magnet under
an influence of a fluid being passed through said tube.
Description BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to flow meters, and more specifically
to flow meters with self-illuminating floaters.
2. Description of the Related Art
It is frequently necessary in an industrial setting to measure
the flow of fluids through pipes. For example, in bulk processing
of compounds in chemical plants the amount of various fluids being
introduced into a reaction vessel must be determined and controlled.
In plant operations requiring pressurized air or steam it is often
desirable or necessary to monitor consumption of these fluids. In
other instances, the supplier of a working fluid or fuel desires
to know the quantity of fluid delivered in order that an appropriate
fee may be charged. A number of fluid flow measuring devices are
currently known.
The most commonly used fluid flow metering devices can be generally
categorized as belonging to one of the following groups.
Positive displacement meters function by receiving and discharging
discrete volumes of fluid through, for example, a reciprocating
piston in a cylinder. The number of cycles of such a device occurring
in a unit period of time is proportional to the flow rate of fluid
passing through the meter. Although accurate, positive displacement
meters are mechanically complex and are highly sensitive to foreign
matter contamination.
Obstruction type meters employ an orifice or other restriction
in the fluid path and the flow rate is calculated from the measured
pressure drop across the restriction. Those meters generally have
limited measurement ranges and are highly sensitive to the flow
patterns of the fluid passing therethrough. Moreover, obstruction
meters provide instantaneous flow measurement, which must be integrated
to evaluate total flow.
Rotating vane type meters are frequently used in measuring fluid
flow. These meters function by causing the flowing fluid to impart
a tangential force on an impeller causing rotation thereof. The
rotational velocity of the impeller is related to volumetric flow
rate.
Variable area flow meter provides a weighted member movably disposed
across an orifice such that the position of the weighted member
determines the orifice area. The weighted member provides an essentially
constant fluid head against the fluid entering the system so that
the displacement of the weighted member is essentially a linear
relation with the rate of volumetric flow of the fluid.
The principal advantage of a variable area flow meter is that,
at low cost, it provides a wide range of capacity with low system
resistances and is essentially linear. One well-known and popular
form of variable area flow meter, often called a rotameter and considered
the closest analog to the present invention, is shown in FIG. 1.
A flow meter 10 utilizes a floater 12 moving vertically within a
tapered tube 14 usually transparent, whose area increases upwardly.
A diameter 16 of the metering floater 12 in the rotameter 10 is
slightly less than the minimum inside diameter 18 of the tube 14
so when the floater 12 is placed within the tube 14 any clearance
between the floater 12 and tube 14 forms an annular orifice 20
a cross sectional area thereof varying in accordance with the position
of the floater 12. In this type of rotameter, a weighted floater
12 contained in an upright tapered tube 14 is raised to a position
of equilibrium between the downward gravitational force of the floater
12 (symbolically shown by an arrow 22) and the upward force of the
fluid flowing past the floater 12 through the annular orifice 20
surrounding the floater 12 which force is symbolically shown by
arrows 24. This position of equilibrium is therefore a function
of flow rate--the greater the flow rate, the higher the vertical
position of the floater.
When the stream of fluid to be measured is made to enter the lower
end 26 of the tube 14 it causes the floater 12 to rise to a height
where its weight is just balanced by the pressure drop across the
orifice 20. At the same time, the floater 12 rotates, and the very
term "rotameter" was derived from the fact that floaters
have slits (like those with reference numeral 28 in FIG. 1) to impart
a rotational force thereto for the purpose of centering and stabilizing
the floater. The tube 14 is typically made of glass or other suitable
materials imprinted with a graduated scale 30 such that the position
of the floater 12 may be correlated with flow rate of the particular
fluid under test. High sensor 32 and low sensor 34 may be installed
outside the tube to catch the highest and lowest permissible readings,
36 and 38 respectively.
A disadvantage of the rotameter described in the above is that
visual reading the results of the tests is infrequently difficult
since the graduated scale 30 may not be clearly visible because
of absence of outer light--in dark periods of a day or when the
flow meter is placed, say, under a machine. Another reason for the
visual reading to be impaired is particles in the flow that may
cause fouling and/or scaling of the tube 14. These reasons may cause
either misreading the results or make reading impossible at all.
SUMMARY OF THE INVENTION
Therefore, the object of the present invention is to provide a
flow meter that, while possessing the advantages of the flow meters
known in the art, would be free of their disadvantages.
One more object of the invention is to provide a flow meter with
easily readable metering results.
Still one more object of the present invention is to provide a
flow meter with a self-illuminating floater.
According to the present invention, providing a variable area flow
meter that comprises a housing and a floater therein attains the
above objects. The housing is placed inside a U-shaped permanent
magnet, and the floater includes a rotor coil. Connected to the
rotor coil is a DC bulb. An ascending fluid flow rotates the floater.
The rotation of the floater with the rotor coil in the magnetic
field of the permanent magnet causes a direct current to flow through
the bulb. Light from the bulb makes it easier to read the results
of metering.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects, as well as advantages and features of the present
invention will be better understood from an ensuing detailed description
of the preferred embodiment thereof when considered in conjunction
with the accompanying drawing where
FIG. 1 is a sketch illustrating a prior art design of the flow
meter improved by the present invention; and
FIG. 2 shows a view of the flow meter with a self-illuminating
floater according to principles of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 2 where elements similar to those depicted
in FIG. 1 are assigned same reference numerals, a flow meter 10
constituting an object of the present invention comprises a housing
40 including a tube 14 and a floater 12. In general, the tube
14 may have a cylindrical shape and a uniform diameter of its inner
hollow 42 along its entire length. It is preferable, however, that
the inner hollow have a profile of a truncated cone, whose cross-section
area increases from its minimal value at a lower end 26 to its maximum
value at its upper end 44.
The housing 40 of the flow meter 10 is placed inside a permanent
magnet 46 expanding along the tube 14 and having a U-shape cross-section,
a vertical axis (not shown) of the housing preferably coinciding
with a vertical axis of symmetry (not shown) of the U-shape permanent
magnet 46. Located inside the tube 14 is a metering floater 12 comprising
a head 48 of a larger diameter and a body 50 of a smaller diameter,
the head diameter 16 being slightly less than the minimal diameter
18 of the tube 14 at its lower end 26. The head 48 is provided with
slits 28 on its surface, which contribute in operation to imparting
a rotational force to the floater 12 for the purpose of centering
and stabilizing the floater.
The floater 12 is provided with an electromagnetically operated
source of light. Specifically, the floater comprises a rotor coil
52 therein that has its ends 54 connected to a DC bulb 56. The coil
52 and the bulb 56 in their combination constitute the source of
light.
In operation, when a fluid, which, as the case may be, is a gas
or liquid flow, goes up through the tube 12 it engages slits 28
on the head 48 of the floater 12 and the floater starts rotating.
A position of the floater heightwise inside the tube 14 is defined
by the relation between the rate, at which the fluid is received
in the tube 14 and the weight of the floater 12. In general, the
volume Q of the fluid flowing through the flow meter for a time
unit is defined as a product of the area A, through which the fluid
flows, and the velocity V, at which the fluid flows through the
area A:
The tube 14 can be made of glass or other convenient translucent
or transparent material, such that the light of the bulb 56 can
be viewed. A graduated scale 30 is applied to (for example, imprinted
on) the tube 14 such that the exact position of the floater 12 may
be correlated with flow rate of the particular fluid under test.
High sensor 32 and low sensor 34 may be installed outside the tube
to catch the highest and lowest permissible readings, 36 and 38
respectively. In this way, flow high/low alarm can be realized,
as well as related PID (standing for Proportional, Integral, Derivative)
control or monitoring function.
The rotation of the floater 12 takes place in the magnetic field
created by the permanent magnet 46 which field permeates the tube
14. Crossing field lines induces a voltage in the rotor coil 52
of the floater 12 and an electric current starts flowing through
the bulb 56 turning it on.
Providing a flow meter with a source of light brings a number of
advantages. With such a device, it is now easy to find out the exact
flow status. While the floater is rotating and shining, the actual
flow rate can be determined. If there is no rotation and the light
is therefore off, it is a symptom that some error occurred such
as clogging the fluid. Additionally, the light does not need an
extraneous source of power, except for the permanent magnet 46
and thus is an energy-saver.
While the preferred embodiment of the present invention has been
disclosed hereinabove, it is to be understood that this embodiment
is given by example only and not in a limiting sense. Those skilled
in the art may make various modifications and additions to the preferred
embodiment chosen to illustrate the invention without departing
from the spirit and scope of the present contribution to the art.
Accordingly, it is to be realized that the patent protection sought
and to be afforded hereby shall be deemed to extend to the subject
matter claimed and all equivalence thereof fairly within the scope
of the invention. |