Water softener abstract
A flow control includes a conduit and a flow control washer disposed
in the conduit between the conduit's inlet and the outlet. A gas
inlet passage opens into the conduit, preferably at a location just
downstream of the flow control washer, to permit a gas (typically
ambient air) to enter a liquid stream flowing through the flow control
washer. The admission of a gas into this liquid stream reduces noise
generated by liquid flow through the flow control washer. Gas induction
and noise reduction capabilities may be enhanced by admitting the
gas fluid into a low pressure region of a venturi located in the
conduit downstream of the flow control washer. The flow control
is particularly useful in a wastewater drain of a water softener
control valve, but is also useful in a variety of other applications.
A method of reducing noise in a flow control is also provided.
Water softener claims
What is claimed is:
1. A flow control comprising: (A) a conduit including an inlet,
an outlet, and an outer peripheral surface, a gas inlet passage
being formed in said conduit and being configured to permit a gas
to enter said conduit between said inlet and said outlet; and (B)
a flow control washer that is disposed in said conduit between said
inlet and said outlet, said flow control washer being configured
to maintain a generally constant volumetric liquid flow rate through
said flow control despite pressure fluctuations at said inlet of
said conduit, wherein said gas inlet passage opens into a low pressure
region of said conduit located between said flow control washer
and said outlet, wherein said low pressure region comprises a venturi,
said venturi including a throat, an inlet portion that is located
upstream of said throat and that tapers inwardly toward said throat,
and an outlet portion that is located downstream of said throat
and that tapers outwardly away from said throat, and wherein said
gas inlet passage opens into said venturi downstream of said inlet
portion, wherein said venturi is formed in said conduit, and wherein
said conduit is formed from two interconnected sections, and wherein
said flow control washer is positioned between said sections.
2. A flow control comprising: (A) a conduit including an inlet,
an outlet, and an outer peripheral surface, a gas inlet passage
being formed in said conduit and being configured to permit a gas
to enter said conduit between said inlet and said outlet; and (B)
a flow control washer that is disposed in said conduit between said
inlet and said outlet, said flow control washer being configured
to maintain a generally constant volumetric liquid flow rate through
said flow control despite pressure fluctuations at said inlet of
said conduit, wherein said gas inlet passage opens into a low pressure
region of said conduit located between said flow control washer
and said outlet, wherein said low pressure region comprises a venturi,
said venturi including a throat, an inlet portion that is located
upstream of said throat and that tapers inwardly toward said throat,
and an outlet portion that is located downstream of said throat
and that tapers outwardly away from said throat, and wherein said
gas inlet passage opens into said venturi downstream of said inlet
portion, and wherein said venturi is formed in an insert that forms
at least part of said conduit and that is mounted in a fitting,
and wherein said gas inlet passage is formed from a bore in said
insert, a passage between said insert and said fitting, and a bore
in said fitting that opens to the ambient atmosphere.
3. A flow control comprising: (A) a conduit including an inlet,
an outlet, and an outer peripheral surface, a gas inlet passage
being formed in said conduit and terminating in a gas inlet that
is configured to permit a gas to flow into said gas inlet passage
and enter said conduit between said inlet and said outlet; and (B)
a flow control washer that is disposed in said conduit between said
inlet and said outlet, said flow control washer being configured
to maintain a generally constant volumetric liquid flow rate through
said flow control despite pressure fluctuations at said inlet of
said conduit, wherein entrance of the gas attenuates noise generation
that would otherwise occur through operation of said flow control
washer, wherein said gas inlet passage includes a bore having a
diameter of between 0.020" and 0.060".
4. A flow control of claim 3 wherein said bore has a diameter
of about 0.035".
5. A flow control comprising: (A) a conduit including an inlet,
an outlet, and an outer peripheral surface, a gas inlet passage
being formed in said conduit and terminating in a gas inlet that
is configured to permit a gas to flow into said gas inlet passage
and enter said conduit between said inlet and said outlet; (B) a
flow control washer that is disposed in said conduit between said
inlet and said outlet, said flow control washer being configured
to maintain a generally constant volumetric liquid flow rate through
said flow control despite pressure fluctuations at said inlet of
said conduit, wherein entrance of the gas attenuates noise generation
that would otherwise occur through operation of said flow control
washer; and (C) a one-way valve that is disposed in said gas inlet
passage.
6. A flow control comprising: (A) a conduit including an inlet,
an outlet, and an outer peripheral surface, a gas inlet passage
being formed in said conduit and being configured to permit a gas
to enter said conduit between said inlet and said outlet; (B) a
flow control washer that is disposed in said conduit between said
inlet and said outlet, said flow control washer being configured
to maintain a generally constant volumetric liquid flow rate through
said flow control despite pressure fluctuations at said inlet of
said conduit; and (C) a one-way valve that is disposed in said gas
inlet passage, wherein the one-way valve comprises a duck-billed
valve.
7. A flow control comprising: (A) a conduit including an inlet,
an outlet, and an outer peripheral surface, wherein a venturi is
disposed in said conduit between said inlet and said outlet, said
venturi including a throat, an inlet portion that is located upstream
of said throat and that tapers inwardly toward said throat, and
an outlet portion that is located downstream of said throat and
tapers outwardly away from said throat, and wherein an ambient air
inlet passage is formed in said conduit and terminates in an ambient
air inlet that is configured to permit ambient air to flow into
said ambient air inlet passage and enter said venturi downstream
of said inlet portion; and (B) a flow control washer that is disposed
in said conduit between said inlet and said venturi, said flow control
washer being configured to maintain a generally constant volumetric
liquid fluid flow rate therethrough despite pressure fluctuations
at said inlet of said conduit, wherein entrance of the ambient air
attenuates noise generation that would otherwise occur through operation
of said flow control washer.
8. A control valve comprising: (A) a service port configured for
connection to a resin tank containing a treatment medium; (B) an
inlet port configured for connection to a source of untreated water;
(C) a treated water outlet port; (D) a wastewater drain port; and
(E) a flow control coupled to said wastewater drain port, said flow
control including (1) conduit including an inlet, an outlet, and
an outer peripheral surface, wherein a venturi is disposed in said
conduit between said inlet and said outlet, said venturi including
a throat, an inlet portion that is located upstream of said throat
and that tapers inwardly toward said throat, and an outlet portion
that is located downstream of said throat and that tapers outwardly
away from said throat, and wherein an ambient air inlet passage
is formed in said conduit and is configured to permit ambient air
to enter said venturi downstream of said inlet portion from a location
external of said water softener control valve; (2) a one way valve
disposed in said ambient air inlet passage; and (3) a flow control
washer that is disposed in said body between said inlet and said
venturi, said flow control washer being configured to maintain a
generally constant fluid volumetric liquid flow rate therethrough
despite pressure fluctuations at said inlet.
9. A water softener comprising: (A) a brine tank; (B) a resin tank
contain a treatment medium; and (C) a water softener control valve
including (1) a brine port fluidically coupled to said brine tank;
(2) a service port fluidically coupled to said resin tank; and (3)
an inlet port configured for connection to a source of untreated
water; (4) a treated water outlet port; (5) a wastewater drain port;
and (6) a flow control coupled to said wastewater drain port, said
flow control including (a) a conduit including an inlet, an outlet,
and an outer peripheral surface, wherein a venturi is disposed in
said conduit between said inlet and said outlet, said venturi including
a throat, an inlet portion that is located upstream of said throat
and that tapers inwardly toward said throat, and an outlet portion
that is located downstream of said throat and that tapers outwardly
away from said throat, and wherein an ambient air inlet passage
is formed in said conduit and is configured to permit ambient air
to enter said venturi downstream of said inlet portion from a location
external of said water softener control valve; (b) a one way valve
disposed in said ambient air inlet passage; and (c) a flow control
washer that is disposed in said body between said inlet and said
venturi, said flow control washer being configured to maintain a
generally constant volumetric liquid flow rate therethrough despite
pressure fluctuations at said inlet.
10. A method of controlling flow of a liquid through a conduit
comprising: (A) directing the liquid to flow through said conduit
at an initial supply pressure that fluctuates; (B) directing the
liquid through an aperture in a flow control washer located within
said conduit, said aperture varying in size with fluctuations in
supply pressure so as to maintain an at least generally constant
volumetric liquid flow rate through said aperture; and (C) attenuating
noise generation that would otherwise occur through operation of
said flow control washer by admitting a gas into said conduit.
11. A method of claim 10 wherein the noise attenuation step comprises
admitting ambient air into a low pressure region of said conduit
located downstream of said flow control washer.
12. A method of claim 11 wherein said low pressure region comprises
a venturi having a throat, an inlet portion that is located upstream
of said throat and that tapers inwardly toward said throat, and
an outlet portion that is located downstream of said throat and
that tapers outwardly away from said throat, and wherein the noise
attenuation step comprises admitting ambient air into said venturi
at a location downstream of said inlet portion.
13. A method of claim 10 wherein the noise attenuation step comprises
admitting ambient air into an ambient air inlet passage opening
into said conduit, and further comprising preventing liquid flow
out of said ambient air inlet passage via operation of a one-way
valve disposed in said ambient air inlet passage.
14. A method of claim 10 wherein the noise attenuation step comprises
reducing noise levels by at least 5 decibels when compared to noises
that would be generated by flow of the same liquid through said
orifice at the same average supply pressure and the same volumetric
flow rate.
15. A method of claim 10 wherein the step (A) comprises directing
liquid through said conduit at a volumetric flow rate of between
0.5 gpm and 25 gpm.
16. A method of claim 10 wherein the step (A) comprises directing
liquid into said conduit at an average supply pressure of between
20 psi and 125 psi.
17. A flow control comprising: (A) a conduit including an inlet
and an outlet; (B) a flow control washer that is disposed in said
conduit between said inlet and said outlet, said flow control washer
being configured to maintain a generally constant volumetric liquid
flow rate through said flow control despite pressure fluctuations
at said inlet of said conduit; and (C) means, communicating with
said conduit, for attenuating noise generation that would otherwise
occur through operation of said flow control washer by admitting
a gas into said conduit, wherein the means for attenuating noise
generation comprises a gas inlet passage opening into said conduit
and configured to permit a gas to enter said conduit between said
inlet and said outlet, wherein said gas inlet passage opens into
a low pressure region of said conduit located between said flow
control washer and said outlet, and wherein said low pressure region
comprises a venturi, said venturi including a throat, an inlet portion
that is located upstream of said throat and that tapers inwardly
toward said throat, and an outlet portion that is located downstream
of said throat and that tapers outwardly away from said throat,
and wherein said gas inlet passage opens into said venturi downstream
of said inlet portion.
18. A flow control of claim 17 wherein said gas inlet passage
opens into said throat.
19. A flow control of claim 17 wherein said gas inlet passage
opens into said downstream portion of said venturi.
Water softener description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to flow control devices and, in particular,
to a flow control having a flow control washer that maintains a
generally constant volumetric flow rate through a liquid stream
despite fluctuations in supply pressure.
2. Description of the Related Art
Flow controls are commonly used in appliances such as dishwashers,
drinking fountains, and water softeners to compensate for variations
in water supply pressure. The typical flow control comprises an
annular flexible flow control washer mounted in a conduit such that
water flowing through the conduit must flow through a central orifice
in the flow control washer. The flow control washer and its support
in the conduit are configured so that the orifice constricts as
the water pressure increases, thereby maintaining a generally constant
volumetric liquid flow rate through the conduit despite variations
in supply pressure. A flow control of this general type has been
used in water softeners as is detailed in U.S. Pat. No. 4210532
to Loke and in U.S. Pat. No. 5162080 to Dragger.
Flow controls of the above-mentioned type tend to be very noisy
in operation, possibly due to cavitation caused by the pressure
drop across the washer and/or to vibrations of the washer itself.
In fact, in the case of a water softener, the whistling noise generated
by the flow of water through the flow control can often proprogate
through the pipes and be heard throughout much of the building.
This noise problem has been recognized and addressed, but never
satisfactorily. For instance, U.S. Pat. No. 5226446 to Cooper
proposes a rather complex anticavitation arrangement disposed downstream
of the flow control washer. U.S. Pat. No. 3250342 to Petry proposes
an expansion duct having apertures to recycle a portion of the fluid
flow. U.S. Pat. No. 3712341 to Constantin proposes a flow separator
for separating a downstream fluid influx from an upstream fluid
flow. All of these arrangements are relative complex, are relatively
expensive to manufacture and install, and are of questionable effectiveness.
In view of the foregoing, it would be desirable to provide a flow
control that solves the noise problems associated with prior flow
controls in a simple and effective manner.
SUMMARY OF THE INVENTION
The invention, which is defined by the claims set out at the end
of this disclosure, is intended to solve at least some of the problems
noted above. In accordance with a first aspect of the invention,
the above-identified need is satisfied by providing a flow control
comprising a conduit and flow control washer disposed in the conduit
between its inlet and its outlet. "Conduit," as used herein,
means an enclosed passageway capable of receiving a flow control
washer. An ambient fluid passageway opens into the conduit, preferably
at a location just downstream of the flow control washer, to permit
a gas (typically ambient air) to enter a liquid stream flowing from
the flow control washer. The admission of the gas into this liquid
stream reduces noise generated by liquid flow through the flow control
washer. Gas induction and noise reduction capabilities may be enhanced
by admitting the gas into a low pressure region of a venturi located
in the conduit adjacent the flow control washer. The venturi may
be formed integrally with the conduit or provided as a separate
insert fitted in the conduit.
A method of reducing noise in a flow control is also provided.
In the method, liquid flows through a flow control washer of a flow
control conduit at a volumetric flow rate that remains generally
constant, despite pressure fluctuations in the flowing liquid, due
to operation of the flow control washer. A gas (typically ambient
air) is drawn into the liquid flow to reduce the noise that would
otherwise be generated by operation of the flow control.
The flow control can be used in any application where the flow
rate is controlled within a particular pressure range. Examples
of uses for the flow control include, but are not limited to, water
softeners, water fountains, eye washes, dishwashers, and safety
showers. If used on conjunction with a simple on/off valve, it can
also be used do measure or dispense a given volume of fluid, without
having to make volumetric measurements, simply by relying the flow
control to maintain a desired fluid flow rate therethrough and automatically
or manually closing the valve at the appropriate time. Hence, if
a flow control maintains a flow rate therethrough at 2 gpm, 20 gallons
can be reliably measured or dispensed simply by closing an associated
valve after 10 minutes of flow through the flow control.
These and other objects, advantages, and features of the invention
will become apparent to those skilled in the art from the detailed
description and the accompanying drawings. It should be understood,
however, that the detailed description and accompanying drawings,
while indicating preferred embodiments of the present invention,
are given by way of illustration and not of limitation.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred exemplary embodiments of the invention are illustrated
in the accompanying drawings, in which like reference numerals represent
like parts throughout and in which:
FIG. 1 is a sectional elevation view of a vessel incorporating
a flow control constructed in accordance with a first embodiment
of the invention;
FIG. 2 is a side elevation view of a second, more practical embodiment
of a flow control in accordance with the invention;
FIG. 3 is a sectional perspective view of the flow control of FIG.
2;
FIG. 4 is a perspective view of a third preferred embodiment of
a flow control in accordance with the invention;
FIG. 5 is a sectional elevation view of the flow control of FIG.
4 taken generally along line 5--5 in FIG. 4;
FIG. 6 is a sectional elevation view of the flow control of FIG.
4 taken generally along line 6--6 in FIG. 5; and
FIG. 7 is a perspective view of a water softener that incorporates
a flow control constructed in accordance with the invention.
Before explaining embodiments of the invention in detail, it is
to be understood that the invention is not limited in its application
to the details of construction and the arrangement of the components
set forth in the following description or illustrated in the drawings.
The invention is capable of other embodiments or being practiced
or carried out in various ways. Also, it is to be understood that
the phraseology and terminology employed herein is for the purpose
of description and should not be regarded as limiting.
DETAILED DESCRIPTION
1. Resume
Pursuant to the invention, a flow control is provided that is configured
to reduce or even eliminate noise associated with previous flow
controls. The flow control includes a bore that draws a gas into
a liquid stream in the vicinity of a flow control washer of the
flow control for purposes of noise reduction. It has been discovered
that the noises caused by the flow of liquid through the washer
can be reduced or even eliminated simply by including a small bore
in the flow control just downstream of the flow control washer for
the admission of the gas, typically ambient air.
2. System Overview and First Embodiment of Flow Control
Referring to the drawings and initially to FIG. 1 a vessel 10
is schematically illustrated that employs a flow control 12 that
is constructed in accordance with a preferred embodiment of the
invention. The vessel 10 may be any system or structure from which
water or another liquid is intended to flow at a generally constant
volumetric flow rate. Examples of such structures are drinking fountains
and eye washers. The vessel 10 could also be a backwashable filter,
in which case the flow control 12 would be used in a control valve
used to help control the backwashing process. The vessel 10 includes
an outlet port 14 for the discharge of liquid, typically water,
to another location, typically the ambient atmosphere. The liquid
could also be discharged to a pressurized outlet. The outlet port
14 is coupled to a discharge line (not shown) by an elbow fitting
16. The elbow fitting 6 includes an annular lip 18 around its outer
periphery that rests against a shoulder 20 of the outlet port 14.
An O-ring 22 which is disposed in a groove 24 in the outer periphery
of the elbow 16 forms a seal between an inner periphery of the
outlet port 14 and the elbow 16.
The flow control 12 may be provided as a standalone item as in
the illustrated embodiment or as part of a more complex valve assembly.
The flow control 12 also may be formed integrally with an existing
conduit or inserted into that conduit. In the embodiment of FIG.
1 the flow control 12 is inserted in a lower, vertical leg 26 of
the elbow fitting 16. The flow control 12 of the embodiment of FIG.
1 comprises 1) a tubular conduit in the form of a plastic tube 28
and 2) a flow control washer 30 mounted in the tube 28 . The tube
28 has an inlet 32 an outlet 34 and an outer peripheral surface
36. The outer peripheral surface 36 is press-fit into the lower
leg 26 of the elbow 16 and sealed to the elbow 16 by an O-ring 38
mounted on a groove 40 in the outer peripheral surface 36 of the
tube 28. As is conventional, the flow control washer 30 comprises
an annular elastomeric washer having an outer periphery 42 and a
center orifice 44. The outer periphery 42 is held in place within
the tube 28 and sealed against an inner peripheral surface 46 of
the tube 28 in a conventional manner. Alternatively, and as is more
typically the case in flow controls, the washer 12 could simply
rest on a shelf-like seat and be sealed to the seat during operation
by the pressure differential thereacross. The center orifice 44
forms a flow path for water or another liquid through the washer
30. The flow control washer 30 is configured so that the diameter
of the orifice 44 constricts generally proportionally as the pressure
drop across the washer 30 increases, thereby maintaining the volumetric
flow rate of liquid through the washer 30 at least generally constant
regardless of variations in supply pressure. Hence, fluid travels
through the orifice 44 in the flow control washer 30 at a generally
constant volumetric flow rate, exiting the tube 28 and is discharged
from the fitting 16.
The flow control 12 also includes a passageway 52 that admits a
gas into the flow control 12 in a low pressure region of the flow
control. The passageway 52 extends through the elbow 16 through
the tube 28 and into the interior of the tube 28 at a location downstream
of the flow control washer 30. The passageway 52 of the embodiment
comprises a simple bore drilled through the fitting 16 and tube
28. The bore 52 permits a gas to enter the liquid stream flowing
from the flow control washer 30 as is shown by arrow 53. The gas
will typically comprise ambient air and, therefore, will hereafter
be referred to as "air" for the sake of convenience. It
has been observed that the flow of liquid through the flow control
washer 30 causes a venturi effect that produces low pressure that
draws air into the bore 52 and discharges a frothy air/liquid mixture
from the outlet 46. The manner in which the bore 52 actually eliminates
the noise that is associated with the flow control washer 30 is
unknown. While applicant does not wish to be restricted to a particular
theory of how the bore 52 in the inventive flow control 12 reduces
or even eliminates noise, the following theory explanation of how
the bore 52 functions.
In conventional flow controls, air is distilled or otherwise removed
from the liquid passing through the flow control washer. This and/or
other factors generate noise, possibly by 1) cavitation in the low
pressure region of the flow control downstream of the flow control
washer and/or 2 vibration of the flow control washer at its resonant
frequency. These noises can be carried and amplified throughout
a building that includes the device having the flow control. It
is believed that the introduction of air into the flow control 12
detunes the rubber of the flow control washer 30. The detuning is
believed to change the natural frequency of the flow control washer
30 sufficiently to avoid resonance. It is also believed that, in
the inventive flow control 12 the bore 52 negates a low pressure
created by the accelerated liquid. That is, the flow of air into
the liquid stream raises the minimum pressure in the system to a
level that prevents cavitation.
The desired upper diameter of the bore 52 is limited by the production
of noise from the air induction itself, while the desired lower
diameter of the bore 52 is limited by the ability of the flow control
12 to draw enough ambient air into the flow control 12 to achieve
the desired noise reduction effect in the tube 28. When the discharged
liquid is water and the tube 28 has a diameter on the order of 0.5"
to 2.0", the bore diameter preferably is between 0.020"
and 0.060", and preferably about 0.035".
Flow controls constructed in accordance with the invention can
accommodate a variety of volumetric flow rates. Depending on the
sizing of the flow control flow rates of from about 0.5 gpm to about
25 gpm or even higher can be accommodated. They can also accommodate
a wide range of supply pressures of, e.g., from less than 20 psig
to more than 12.5 psig, for a typical application in which the liquid
is discharged to the atmosphere at 14 psig.
3. Second Embodiment of the Flow Control
A second preferred embodiment of the flow control 112 is shown
in FIGS. 2-3. The flow control 112 of the second preferred embodiment
is similar to the flow control 12 of first preferred embodiment.
Elements of the flow control 112 of FIGS. 2-3 corresponding to elements
of the flow control 12 of FIG. 1 are incremented by 100. Flow control
112 therefore includes a tubular conduit 128 and a flow control
washer 130. The conduit 128 has an inlet 132 and an outlet 134.
A passageway 152 is formed in the conduit 128 downstream of the
flow control washer 130 to admit gas into the conduit 128 for noise
reduction purposes. However, the flow control 112 of this embodiment
is significantly different from the embodiment of FIG. 1 in some
respects.
For instance, the conduit 128 is configured to be mounted in series
between two other conduits (not shown) and to facilitate mounting
of the flow control washer 130 in the conduit 128. The conduit 128
therefore is formed from a connector having female and male sections
154 156 secured to each other via a swage fitting 158 threaded
onto the female section 154 and secured to male section 156 by locking
ring 172. The washer 130 is positioned between a downstream axial
end 166 of the male section 156 and a shoulder 168 on the female
section 154. The female section 154 is sealed to the male section
156 by an O-ring 170 disposed radially between the sections 154
156 in the vicinity of the swage fitting 158.
In addition, the interior of the female fitting 160 is shaped to
enhance the venturi effect of liquid flow though the flow control
112 in order to enhance airflow into the flow conduit 128 and the
resultant noise reduction. Specifically, a venturi 174 is formed
in the conduit 128 downstream of the washer 130. The venturi 174
includes a conically tapered inlet 176 a conically tapered outlet
178 and a relatively narrow throat 180 disposed between the inlet
176 and the outlet 178. The bore 152 opens into the interior of
the conduit 128 at the throat 180 of the venturi 174 where the
pressure drop of fluid flowing through the flow control 112 is a
maximum.
A one-way valve 182 is also provided in this embodiment to prevent
liquid from back flowing out of the bore 152. Suitable valves include,
but are not limited to, check valves, flapper valve, and duck-billed
valves. The illustrated valve 182 is a duck-billed valve disposed
in a boss 184 containing an outer end portion of the bore 152. The
valve 182 is formed from a rubber or other elastomeric material
that is slit down its middle. The rubber halves of the valve 182
move apart to admit air into the bore 152 but close to prevent
the egress of liquid from the bore 152.
In use, a liquid such as water enters the inlet 132 of the conduit
128 as represented by the arrow 148 in FIG. 3 flows through a central
orifice 144 in the flow control washer 130 flows through the venturi
174 and exits the outlet 134 of the conduit 128. Supply pressure
fluctuations are accommodated by expansion and constriction of the
orifice 144 to maintain a substantially constant volumetric flow
rate through the flow control washer 130 and downstream components
of the flow control 112. The pressure drop created by liquid flow
through the washer 130 and augmented by the venturi 174 draws a
gas such as ambient air through the bore 152 and into the throat
180 of the venturi 174 as represented by the arrow 153 thereby
attenuating noises that otherwise would be generated by operation
of the flow control 112. The rubber halves of the duckbill valve
182 move apart to admit air into the bore 152 during this process,
but close to prevent the egress of liquid form the bore 152.
4. Third Embodiment of the Flow Control
A third preferred embodiment of the flow control 212 which is
illustrated in FIGS. 4-6 differs from the second preferred embodiment
in that the venturi 274 is configured for installation in a separate
fitting rather than being formed integrally with a fitting. Elements
of the flow control 212 of FIGS. 4-6 corresponding to elements of
the flow control 112 of FIGS. 2 and 3 are incremented by 100. The
flow control 212 therefore includes a conduit 228 incorporating
an integral venturi 274 and a flow control washer 230 mounted in
the conduit 228 and having a central orifice 244.
The flow control 212 of this embodiment is configured to minimize
redesign of a flow control used in a drain fitting of a water softener
control valve such as the valve 186 illustrated in FIG. 7. The water
softener control valve 186 includes a brine port 188 connected to
a brine tank 190 a service port 192 connected to a resin tank 194
containing a treatment medium, an inlet port 196 connected to an
untreated water inlet line 198 an outlet port 300 connected to
a treated water outlet line 302 and a wastewater discharge port
304 opening into a wastewater discharge fitting 306 connected to
a drain line 308. The flow control 212 is disposed in the wastewater
discharge fitting 306.
Referring back to FIGS. 4-6 the discharge fitting 306 comprises
an elbow 216 incorporating the flow control 212. The elbow 216 includes
1) a vertical upstream leg 226 configured for mounting in the wastewater
discharge port 304 (FIG. 7) and 2) a horizontal downstream leg 308
configured for threaded connection to the drain line 308 (FIG. 7).
The flow control 212 is formed in an insert 310 that is installed
into the vertical leg 226 of the fitting 216 from the inner end.
An outer peripheral surface of the insert 310 is sealed to an inner
peripheral surface of the vertical leg 226 by a pair of spaced O-rings
316 317. Sliding movement of the insert 310 due to pressure differential
from operation of the flow control into the vertical leg 226 of
the fitting 216 is limited by engagement of an annular ring 314
on the insert 310 with the upstream end of the fitting 216. The
fitting is otherwise held in place by friction from O-rings 314
and 316. A boss 315 extends upstream from the ring 314 and is configured
to extend into the discharge port 304 of the water softener control
valve 186. The flow control washer 230 is also positioned loosely
within the boss 315 adjacent the ring 314.
The venturi 274 includes a conically tapered inlet 276 a conically
tapered outlet 278 and a relatively narrow throat 280 disposed
therebetween. An air inlet passage connects the ambient atmosphere
to a low pressure region of the venturi 274 to permit air to flow
into the low pressure region as represented by the arrow 253. In
the illustrated embodiment, the passage is formed from a bore 251
through a boss 284 on the fitting 216 through an annular space
208 formed between the outer peripheral surface of the insert 310
and the inner peripheral surface of the fitting 216 and through
a bore 252 opening into the outlet portion 278 of the venturi 274
near the throat 280. As with the embodiment of FIGS. 2 and 3 the
venturi 274 augments the venturi effect caused by the flow of liquid
through the flow control washer 230 to maximize the noise reduction
effects of airflow into the flow control 212. Finally, and also
as in the second embodiment, a duck-billed one-way valve 282 is
mounted in the boss 284 to prevent water from flowing out of the
flow control 212 via the air inlet passage.
5. Noise Reduction
The data shown in the Tables 1-4 below demonstrate the difference
in noise reduction using a relatively small (0.5" diameter)
elbow for fitting in a water softener drain port fitting constructed
in accordance with the third embodiment of the invention. Data are
shown as "A weighted," which is used for scientific purposes,
and "C weighted," which approximates the human ear. The
fitting was connected to the water softener control valve 185 and
to the drain line 203 with flexible tubes to isolate the flow control
212 from external noise sources. Noise levels were tested at various
flow rates in gallons per minute (GPM). Noise was measured with
air introduced via the bore 252 of the flow control (WITH AIR) and
without air introduced (W/O AIR). The difference between the two
noise measurements is shown in the column labeled "DIFF."
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