Abstrict An oil reclamation system flow meter for measuring the flow rate
of a oil through the system wherein a housing forms a first chamber
that leads through a constricted lower outlet into a second chamber
and the second chamber. The first chamber also includes an intermediate
outlet above the lower outlet and an upper outlet above the intermediate
outlet. Both the intermediate and upper outlets flow into a duct
that opens into the second chamber at a lower end. Oil flows through
an inlet into the first chamber and through the lower outlet when
the rate is below an ideal rate range, through both the lower outlet
and the intermediate outlet when the rate is within the ideal range
and through all three outlets when the rate exceeds the ideal range.
A viewing conduit indicates the level of oil inside the first chamber
and thereby indicates flow rate.
Claims We claim:
1. An oil reclamation system flow meter connectible between two
conduits for measuring the flow of oil therethrough, the meter comprising:
a first housing forming a first chamber, an inlet leading into
the first chamber and lower, intermediate and upper outlets leading
out of the first chamber, the intermediate outlet formed above the
lower outlet and the upper outlet formed above the intermediate
outlet, said lower outlet having a reduced cross section relative
to a cross section of the first chamber;
a second housing forming a bypass duct, the first chamber leading
into the duct through both the intermediate and upper outlets, the
duct forming a duct outlet below the intermediate outlet;
a third housing forming a second chamber below both the first chamber
and the duct, the first chamber leading into the second chamber
through the lower outlet and the duct leading into the second chamber
through the duct outlet; and
means for indicating the oil level in the first chamber.
2. The meter of claim 1 wherein the first, second and third housings
are formed by a single housing.
3. The meter of claim 1 wherein the inlet is proximate the top
of the first chamber.
4. The meter of claim 1 wherein the lower outlet is proximate the
bottom of the first chamber.
5. The meter of claim 1 wherein the first chamber is vertically
oriented and has a substantially uniform horizontal cross sectional
area.
6. The meter of claim 1 wherein the first and second chambers are
substantially vertical chambers.
7. The meter of claim 1 wherein the first housing also forms two
apertures from the first chamber through the housing and the means
for determining the oil level includes a non-opaque conduit secured
to and traversing the distance between the two apertures.
8. The meter of claim 7 wherein an upper of the two apertures is
formed above the inlet and a lower of the two apertures is formed
between the lower and intermediate outlets.
9. The meter of claim 8 wherein the conduit has visible calibration
markings which relate oil level therein to flow rate.
10. The meter of claim 1 wherein the intermediate outlet forms
a passage that is angled downwardly from the first chamber to the
duct.
11. The meter of claim 1 wherein the intermediate outlet includes
several intermediate outlets leading from the first chamber into
the duct and each of the intermediate outlets is formed at a different
height than the others.
12. The meter of claim 1 wherein the duct includes two ducts each
of which forms an outlet that leads into the second chamber, the
intermediate outlet leads into the first duct and the upper outlet
leads into the second duct.
13. The meter of claim 7 wherein the first chamber extends below
the conduit.
14. The meter of claim 1 wherein the meter is used to indicate
if an oil flow rate therethrough is within an ideal range, the ideal
range defined by a minimum flow rate and a maximum flow rate, the
lower outlet being dimensioned so that the highest rate of flow
therethrough prior to a pooling of oil in the first chamber below
the intermediate outlet is equal to the minimum flow rate and the
intermediate outlet being dimensioned so that the highest rate of
flow therethrough prior to a pooling of oil thereabove is equal
to the maximum flow rate less the minimum flow rate.
15. An oil reclamation system flow meter connectible between two
conduits for measuring the flow of oil therethrough, the meter comprising:
a housing forming a substantially vertical and cylindrical first
chamber, a substantially cylindrical inlet leading into the first
chamber and lower, intermediate and upper outlets leading out of
the first chamber, the intermediate outlet formed above the lower
outlet and the upper outlet formed above the intermediate outlet,
the housing also forming a substantially vertical bypass duct, the
first chamber leading into the duct through both the intermediate
and upper outlets, the duct forming a duct outlet below the intermediate
outlet, the housing also forming a second substantially vertical
and cylindrical chamber below both the first chamber and the duct,
the first chamber leading into the second chamber through the lower
outlet and the duct leading into the second chamber through the
duct outlet, the second chamber having a greater minimum cross sectional
area than the first chamber, the housing also forming two apertures
from the first chamber through the housing, an upper of the two
apertures formed above the inlet and a lower of the two apertures
formed between the lower and intermediate outlets; and
a non-opaque conduit secured to and traversing the distance between
the two apertures.
16. The meter of claim 15 wherein the inlet is proximate the top
of the first chamber and the lower outlet is proximate the bottom
of the first chamber.
17. The meter of claim 15 wherein the conduit has visible calibration
markings which relate oil level therein to flow rate.
18. The meter of claim 15 wherein the meter is used to indicate
if a oil flow rate therethrough is within an ideal range, the ideal
range defined by a minimum flow rate and a maximum flow rate, the
minimum cross sectional area of the first chamber dimensioned so
that the highest rate of flow therethrough prior to a pooling of
oil in the first chamber below the intermediate outlet is equal
to the minimum flow rate and the intermediate outlet dimensioned
so that the highest rate of flow therethrough prior to a pooling
of oil thereabove is equal to the maximum flow rate less the minimum
flow rate.
Description FIELD OF THE INVENTION
The present invention relates to oil flow measurement devices and
more particularly to a device for visually indicating the rate of
oil flow through an oil reclamation system.
BACKGROUND OF THE INVENTION
Flow meters for indicating the rate of liquid flow through a conduit
are known in various forms. In most flow measurement applications,
a flow meter must be configured so that it can distinguish among
various flow rates along a continuous flow rate spectrum (e.g. between
1 and 10 gallons per minute (gpm)).
Two flow meters that are capable of indicating flow rates along
a spectrum are described in U.S. Pat. Nos. 4523464 and 3001397.
Each of these two meters relies on a liquid level within a measurement
chamber having a restricted outlet at its lower end. The liquid
level within the chamber is associated with a specific outlet flow
rate.
In other applications, it is advantageous if only a small number
of flow rates, as opposed to a continuous spectrum of rates, is
indicated. For example, in oil reclamation applications in which
a portion of total oil flow in an engine system is routed for liquid
and solid decontamination, there may only be a small ideal range
of flow rates (e.g. between three and four gpm).
In these applications, a preferred meter should operate in a distinct
and easily identifiable manner when the flow rate is within the
ideal range so that an observer can easily identify if the flow
rate is within the ideal range. The flow indication should be rugged
in operation and not readily susceptible to extreme fluctuations
that may be induced by viscosity changes, system vibrations and
other factors. To this end, a large change in indicator status when
the flow rate transitions into or out of an acceptable range, rather
than minute, incremental changes to slight variations in flow rate,
is particularly advantageous.
Unfortunately, the meters described in the patents referenced above
operate in the same manner regardless of flow rate. As flow rate
increases, liquid level increases. In some embodiments, as flow
rate increases, the liquid level rate of increase decreases. Thus,
these meters are incapable of providing a large, quantum change
in indicator status when the flow rate transitions into or out of
an acceptable range.
In these meters differences in liquid viscosity (viscosity results
in shearing stress caused by flow velocity) dramatically affect
flow rate. For this reason these meters must be calibrated to account
for the specific viscosity of the liquid passing therethrough.
Moreover, liquid viscosity can change as a function of ambient
conditions, such as temperature. For example, the shear stresses
associated with oil at a low temperature are greater than the stresses
at a high temperature. Because the meters above must be calibrated
as a function of liquid viscosity, where liquid viscosity changes,
the meters would be inaccurate unless recalibrated.
Therefore, it would be advantageous to have an oil flow rate meter
that could provide a large change in indicator status when the flow
rate transitions into or out of an acceptable range and that can
operate relatively accurately despite different oil viscosities,
temperature variations and other environmental fluctuations.
SUMMARY OF THE INVENTION
The invention is directed to an oil flow meter connectible between
two conduits for measuring the flow of oil therethrough. The meter
comprises a first housing forming a first chamber, an inlet leading
into the first chamber and lower, intermediate and upper outlets
leading out of the first chamber, the intermediate outlet formed
above the lower outlet and the upper outlet formed above the intermediate
outlet. The inlet preferably has a greater minimum cross sectional
area than the first chamber. The lower outlet provides a constricted
discharge with a predetermined flow capacity.
A second housing forms a bypass duct, the first chamber leading
into the duct through both the intermediate and upper outlets. The
duct forms a duct outlet below the intermediate outlet. A third
housing forms a second chamber below both the first chamber and
the duct, the first chamber leading into the second chamber through
the lower outlet and the duct leading into the second chamber through
the duct outlet. The second chamber has a greater minimum cross
sectional area than the first chamber. In one preferred aspect,
the first, second and third housings are formed by a single housing.
The meter also includes means for determining the oil level in the
first chamber.
One object of the invention is to provide a meter that can accurately
provide a relatively stable indicator status when a flow rate operates
within a predetermined acceptable range. With the present meter,
when an inlet flow rate exceeds the flow rate that can pass through
the constricted outlet of the first chamber, a pooling effect takes
place until the pooled oil reaches the intermediate outlet. At this
point, the excess flow passes through the intermediate outlet and
the duct into the second chamber. In this way, the oil level rate
of increase inside the chamber is reduced substantially once the
oil level reaches the intermediate outlet.
If the flow rate increases further, at some point the flow rate
exceeds the flow that can pass through both the constricted outlet
of the first chamber and the intermediate passage. At this point,
the oil level within the chamber again increases rapidly until the
oil level reaches the level of the upper outlet. Thus, three distinct
ranges of oil flow are clearly marked and observable using the present
invention.
Another object is to provide an accurate meter that is inexpensive.
By forming the first chamber, second chamber and duct from a single
housing material, costs are minimized.
Preferably, the inlet is proximate the top of the first chamber,
the lower outlet is proximate the bottom of the first chamber and
the first and second chambers are substantially vertical.
In another preferred aspect, the housing also forms two apertures
from the first chamber through the housing and the means for determining
the height of the oil includes a non-opaque conduit secured to and
traversing the distance between the two apertures. An upper of the
two apertures should be formed above the inlet and a lower of the
two apertures should be formed between the lower and intermediate
outlets. Visible range markings can be provided on the conduit which
relate oil level therein to flow rate.
In yet another preferred aspect, the intermediate outlet forms
a passage that is angled from the first chamber to the duct.
Preferably, the first chamber is vertically oriented and has a
substantially uniform horizontal cross sectional area. Here, the
meter may be used to indicate if oil flow rate therethrough is within
an ideal range, the ideal range defined by a minimum flow rate and
a maximum flow rate. To this end, the cross sectional area of the
first chamber constricted outlet may be dimensioned so that the
highest rate of flow therethrough prior to a pooling of oil in the
first chamber below the intermediate outlet is equal to the minimum
flow rate and the intermediate outlet may be dimensioned so that
the highest rate of flow therethrough prior to a pooling of oil
thereabove is equal to the maximum flow rate less the minimum flow
rate.
In keeping with the object of providing a clear indication of when
the flow rate is within an ideal range, by forming the first chamber
with a substantially uniform horizontal cross sectional area, the
rate of oil height level change can be made to vary quickly at the
boundaries of the ideal flow range and only minimally when the rate
is within the ideal range. This makes it easier for an observer
to identify operation within the ideal range.
Other and further objects and aspects of the present invention
will become apparent during the course of the following description
and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a flow meter according to the present
invention;
FIG. 2 is a bottom plan view of the flow meter in FIG. 1;
FIG. 3 is a cross-sectional view of the flow meter in FIG. 2 taken
along the line 3--3;
FIG. 4 is a cross-sectional view of a flow meter shown in FIG.
2 taken along the line 4--4; and
FIG. 5 is a cross-sectional view of the flow meter shown in FIG.
3 taken along the line 5--5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 a preferred embodiment of the inventive
flow meter 10 includes a housing 12 and a level viewing conduit
14. Referring also to FIGS. 3 4 and 5 the housing 12 is preferably
a single block of rigid material that forms a housing inlet 16
a first chamber 18 a second chamber 20 a housing outlet 22 a
bypass duct 24 a passageway 26 and upper and lower apertures 28
30 respectively.
The block of material that forms the housing 12 is preferably elongate
and has an upper end 32 a lower end 34 and for the purposes of
describing the present embodiment, is defined by two lateral and
oppositely facing side walls 36 and 38 respectively.
Referring to FIGS. 2-5 the first chamber 18 is cylindrical, preferably
has a uniform diameter D1 along its entire length and extends from
the housing upper end 32 to a lower constricted outlet 40 which
opens into the second chamber 20 therebelow, an upper end 42 of
the first chamber 18 being enclosed by the upper end 32 of the housing
12. The constricted outlet 40 is dimensioned to accommodate a predetermined
range of flow rates from zero up to a capacity flow rate, for example,
3 gph, above which the oil flow pools in the first chamber 18.
Referring specifically to FIGS. 3 and 4 the second chamber 20
like the first chamber 18 is preferably cylindrical along its vertical
length and has a uniform diameter D2 that can be greater than the
first chamber diameter D1. The second chamber 20 opens into the
housing outlet 22 therebelow.
The housing inlet 16 is formed proximate the housing upper end
32 and extends horizontally through side wall 36 perpendicular to
the length of the first chamber 18 intersecting the first chamber
18 below the first chamber upper end 42. The housing inlet 16 is
preferably cylindrical having a uniform diameter D3 along its length
that can be greater than the first chamber diameter D1. Outer ends
of both the housing inlet 16 and housing outlet 22 are threaded
for connection to other suitable conduits or pipes through which
oil flow rate is to be measured.
Referring to FIGS. 2-5 the duct 24 is preferably cylindrical,
parallel to the first chamber 18 and does not intersect the first
chamber 18. The housing inlet 16 opens into an upper end of the
duct 24 through an upper outlet 44. At its lower end, the duct 24
opens into the second chamber 20 through a duct outlet 46. Referring
specifically to FIG. 3 preferably, the upper outlet 44 is vertically
above a lower-most edge 48 of the housing inlet 16.
Referring to FIGS. 2 3 and 4 the housing 12 forms the passageway
26 between the first chamber 18 and the duct 24. Preferably, the
passageway 26 slopes upwardly (e.g. at a 60.degree. angle) from
the first chamber 18 to the duct 24. The preferred upward inclination
prevents inadvertent, premature drainage into the by pass duct 24
and reduces the opportunity for vapor lock. The passageway 26 is
formed between the housing inlet 16 and the lower outlet 40 and
defines an intermediate outlet 50 from the first chamber 18. Preferably,
the intermediate outlet 50 is formed approximately half-way along
the length of the first chamber 18.
The upper aperture 28 opens through the housing side wall 38 and
into the first chamber 18 above the housing inlet 16. The lower
aperture 30 opens through the housing side wall 38 and into the
first chamber 18 just above the lower outlet 40 and, preferably,
well below the intermediate outlet 50.
The level viewing conduit 14 is formed of a non-opaque material
such as a clear plastic or tempered glass tube. The conduit 14 includes
an upper horizontal end 52 a lower horizontal end 54 and a vertical
elongated viewing portion 56 that traverses the distance between
the two horizontal ends 52 54 respectively. The horizontal ends
52 54 are formed so that they can be received in the upper and
lower apertures 28 30 respectively. The horizontal ends 52 54
can be secured in the apertures 28 30 in any manner known in the
art (e.g. threaded fitting, epoxy, or some other type of adhesive).
A float ball 58 is preferably provided inside the conduit 14 to
improve visibility of the oil level when the conduit 14 is obscured
by oil film and the like. The float ball 58 is sized so it can easily
move up and down within the viewing portion 56. Referring to FIG.
3 two stops 60 and 62 can be provided, one in either horizontal
end 54 56 that extend inwardly into the conduit 14 so as to block
the float ball 58 so that the float ball 58 remains within the conduit
14. Referring to FIGS. 1 and 3 level markings 64 can be provided
on the viewing portion 56 that correspond to various flow rates
through the meter 10.
The diameter or other cross sectional dimension of the constricted
outlet 40 is chosen so that a first oil flow up to a predetermined
rate can pass therethrough unobstructed. Similarly, the intermediate
outlet 50 and associated passageway 26 are formed so that a second
flow rate can pass therethrough without excessive impedance from
oil viscosity.
To simplify explanation of operation of the inventive flow meter,
it will be assumed that the present flow meter is to be used to
measure the rate of oil flow in a filtration process wherein an
ideal flow rate is between 3 and 4 gallons of oil per minute. In
this case, the inventive meter should ideally and clearly indicate
when the flow rate is below 3 gpm, when the flow rate is between
3 and 4 gpm, and when the flow rate is above 4 gpm. To this end,
the constricted outlet 40 should have a dimension that can pass
up to 3 gpm of oil. In addition, the intermediate outlet 50 and
associated passageway 26 should have a diameter or other cross-section
that passes a range of approximately 1 gpm.
In this case, the first chamber 18 and passageway 26 together would
pass 4 gpm of oil.
To help an observer identify when the flow rate is within the ideal
range, in the present example, between 3 and 4 gpm, two level markings
64a and 64a, one slightly above and one slightly below the intermediate
outlet 50 are provided on the viewing portion 58.
In operation, it will be assumed that initially passes an inlet
flow rate of approximately 2 gpm. In this case, oil entering the
inlet 16 follows the path identified by arrow 69a and passes over
the lower-most edge 48 of the inlet and down through the first chamber
18. Because the 2 gpm flow rate is less than the maximum (i.e. 3
gpm) flow rate that can pass through the constricted outlet 40 the
oil passes through the first chamber 18 the and lower outlet 40
into the second chamber 46 before it exits the flow meter 10.
In this case, the float ball 58 remains at the bottom of the viewing
conduit 14 in its lower horizontal end 54. An observer viewing
the ball 58 at the lower end 54 can surmise that the flow rate through
the meter is below 3 gpm and therefore not within the ideal 3 to
4 gpm range. The observer can then adjust the system to correct
the flow rate accordingly.
Assuming that the flow rate is adjusted upwardly so that the rate
exceeds 3 gpm, immediately when the rate exceeds 3 gpm, the volume
of oil passing through the first chamber 18 exceeds the maximum
flow rate that can pass therethrough and a pooling of the oil below
the intermediate hole 50 begins. When the oil begins to pool, in
addition to pooling inside the first chamber 18 the oil also is
forced up through the lower horizontal end 54 and the viewing portion
56 of the viewing conduit 14 forcing the float ball 58 up and into
the viewing portion 56. The oil continues to pool with increasing
flow rate until it reaches the intermediate outlet 50.
Upon reaching the intermediate outlet 50 oil in excess of the
3 gpm flow rate follows the path identified by arrow 69b and passes
through the outlet 50 and associated passageway 26 from the first
chamber 18 into the bypass duct 24. Fluid entering the bypass duct
24 passes downwardly therethrough and exits the bypass duct 24 through
duct outlet 46 into the second chamber 20. Because the second chamber
20 has a greater diameter D2 than the first chamber D1 the second
chamber 20 can accommodate a greater flow rate and therefore can
accommodate fluid passing through both the first chamber 18 and
the passageway 26.
Assuming that the flow rate into housing inlet 16 does not exceed
4 gpm, the oil entering the inlet passes through the first chamber
18 or passageway 26 and the oil level inside the first chamber 18
will not exceed an upper edge of the intermediate aperture 50. Therefore,
despite rapid increases or decreases in the flow rate between 3
and 4 gpm, the rate of oil level change in the first chamber 18
will be relatively slow as any oil in excess of 3 gpm but below
4 gpm will simply pass through the passage 26 into the duct 24.
For this reason, when the flow rate is in the ideal range (i.e.
between 3 and 4 gpm), the float ball 58 remains at approximately
the same level within the viewing portion 58 between level marks
64a and 64b.
Next, assuming that the flow rate is increased from below 4 gpm
to a level thereabove, both the first chamber 18 and intermediate
outlet 50 flow rates become saturated. Therefore, oil in excess
of 4 gpm again begins to pool within the first chamber 18 this
time above the intermediate outlet 50. Once again, the oil level
inside the first chamber 18 increases and the float ball 58 inside
the viewing conduit 14 follows suit, rising inside the viewing portion
56.
The oil level increases to the point where it reaches the upper
outlet 44. At this point, oil in excess of 4 gpm follows the path
identified by arrow 69c and passes through the upper outlet 44 into
the bypass duct 24 and down into the second chamber 20 therebelow.
Thus, the upper outlet 44 acts as an overflow outlet to allow oil
in excess of the ideal flow rate to pass. When oil is passed through
the upper outlet 44 the float ball 58 is forced up to a relatively
high level (i.e. the level of the upper outlet 44) which is clearly
outside the ideal range and above level mark 64a. An observer can
easily identify the excess flow rate and adjust flow rate accordingly.
It should be appreciated that a very simple flow rate meter has
been described which can be used to easily identify if a flow rate
is within an ideal or acceptable range. With the present meter,
when the flow rate is below an ideal range, ball 58 is at the bottom
of the viewing conduit 14. When the flow rate initially enters the
acceptable range, ball 58 relatively quickly rises to a level indicating
that the ideal rate has been reached. While the flow rate is within
the ideal range, ball 58 moves only minimally, if at all, within
the viewing portion 56. However, immediately when the flow rate
exceeds the upper level of the ideal range, ball 58 is relatively
quickly forced up to a high level inside the viewing conduit 14.
It should be understood that the apparatus described above is only
exemplary and does not limit the scope of this invention, and that
various modifications could be made by those skilled in the art
that would fall under the scope of the invention. While the meter
is described as having a horizontal inlet near its upper end, clearly,
the inlet could be positioned anywhere along the length of the meter
where the inlet will open into the first chamber and, the inlet
need not be horizontal. Furthermore, the invention could be used
to clearly and easily indicate more than a single ideal or acceptable
flow rate range. To this end, the meter could include more than
a single intermediate outlet 50. A second intermediate outlet could
be provided between the intermediate outlet 50 and the lower outlet
40 that is dimensioned to pass another known flow rate. The additional
intermediate outlet, like the first intermediate outlet 50 would
appreciably reduce the rate of ball 58 level change when the rate
is within another range.
Thus, the scope of the invention should be determined from a reasonable
interpretation of the appended claims and not by the details of
the preferred embodiments discussed above. |