Note: Descriptions are shown in the official language in which they were submitted.
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INJECTOR V~LVE
B~CKGROUND OF T~IR INVENTION
The present invention relates generally to an improved
injector valve, and more particularly to an injector valve for
injecting a proportional quantity of a first liquid into a second
liquid flowin~ through the valve. The injector valve means of the
present invention is particularly adapted for injecting small
quantities of fluid into a major flow channel, such as injecting
high dilution ratios in the range of 150:1. The injector valve
means of the present invention is particularly adapted for use
with water as the main flow constituent, with the water being
maintained at relatively high pressures and high temperatures
including temperatures in excess of 200~F., and up to temperatures
in the range of 210F. The injector valve of the present
invention is particularly adapted for use in combination with
systems requiring modest amounts of a fluid to be injected therein
at relatively high pressures and temperatures.
In the past, injector valves have been designed which
include rather complicated and complex flow means. The preferred
technique for injection is to dilute the fluid to be injected into
the main flow, to such an extent that relatively high quantities
of the fluid to be injected are employed. Such an arrangement
contributes to inconvenience in application, particularly when it
is desired to use mobile or porta~le pumps and systems, such as
portable spray systems or the like.
SUMMARY OF THE INVENTION
The present invention utilizes a conventional valve body,
preferably fabricated from stainless steel, with the valve body
having main inlet and outlet ports at opposed ends thereof.
Parallel and dual flow channels are provided, with the primary
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flow cl~nnel beincJ utili~ed to maintain cap~city and pressure, ~nd
with tlle secondary flow chanilel being used to introduce a fluid to
be injected into the overall stream. The arrangement has been
found to be particularly adapted for use with water at relatively
elevated temperatures and pressures.
The improvement of the present invention relates
essentially to the design of the injection chamber which is
utilized in combination with the secondary flow channel. This
injector chamber is defined by axially spaced apart first and
second inwardly tapered flow channels which converge at their
smaller diameter ends to form a modified Venturi arrangement. The
Venturi is provided with an open throat zone which is disposed in
the region between the converging tapered zones. This open
Venturi throat, in turn, defines an injection chamber for
introducing the fluid to be injected into the overall stream. The
injection chamber is in direct communication with an injection
port, with the injectin port providing the third port in the
overall valve body.
By way of further definition, the injection chamber is in
the form of a generally annular enclosure formed within the valve
body, and with the annular enclosure being generally coaxial with
the secondary flow channel. The length of the injector chamber is
substantially coextensive with that of the throat of the Venturi,
and is preferably in the range of approximately two times the
diameter of the secondary channel at points immediately adjacent
the ends or walls of the injection chamber. Furthermore, the
ratio of the cross-sectional area of the annular chamber to that
of the secondary flow channel at the edges of the wall defining
the injection chamber is approximately 6:1. Preferably, the
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annulal chamher is concentric with the bore of the channel,
although other configurations may be advantageously employed.
In order .o reduce the tendency of the heated water to
flash within the valve and to maintain maximum efficiency, the
primary flow channel is smooth and free of obstructions.
Furthermore, it is generally of constant diameter from the inlet
to the outlet. The secondary channel, as indicated earlier, has
tapered portions converging toward the mid-point thereof, with the
region between the ends of the converging tapers being spaced
apart to form the injector chamber.
In terms of flow pattern, as contrasted to the definition
of the valve body, the secondary channel has a diameter or cross-
sectional area which converges from the inlet port to the mid-
point where it joins the injector chamber, and further has a
diverging or increasing cross-sectional diameter from the juncture
with the injector chamber and toward the outlet port. As a result
of this configuration and design, the valve structure has been
found to be well adapted for use when precise high dilution ratios
are required, and where water at high temperature and high
pressure are being utilized.
Therefore, it is a primary object of the present invention
to provide an improved injector valve which is particularly
designed to inject fluids in precise quantities and at high
dilution ratios, and to function with water at relatively high
pressures and temperatures in excess of about 200F.
It is a further object of the present invention to provide
an improved injector valve which is designed for injecting a
proportional quantity of a first liquid in very precise quantities
into a flow of a second liquid where these flow rates are well
defined and controlled, and wherein spaced apart distinct primary
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and secondary flow channels are provided, and with the primary
flow channel havlng an outer periphery which is substantially
smooth and cylindrical, and with the secondary flow channel having
an outer periphery which forms a Venturi with an injection chamber
at the throat of the Venturi.
Other and further objects of the present invention will
become apparent to those skilled in the art upon a study of the
following specification, appended claims, and accompanying
drawing.
IN THE DRAWING
Figure 1 is an exploded view of an injector valve prepared
in accordance with the present invention; and
Figure 2 is a vertical sectional view taken along the line
and in the direction of the arrows 2-2 of Figure 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with the preferred embodiment of the present
invention, and with particular attention being directed to
Figures 1 and 2 of the drawing, the injector valve generally
designated 10 comprises a valve body 11 having a pair of flow
channels extending therethrough, including a primary flow channel
12, and a secondary flow channel 13. Inlet and outlet ports are
provided as at 14 and 15, with the ports being in common for the
primary and secondary flow channels 12 and 13 respectively. As
indicated, inlet and outlet ports 14 and 15 are preferably
threaded so as to receive inlet and outlet conduits.
A third port is provided, such as injection port 17.
Injection port 17 may be provided with an adaptor block (not
shown) so as to accommodate fittings for the fluid to be injected
into the main flow. Conventional screws or cap screws may be
employed to attach such an adaptor block to body 11.
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With attention being redirected to Figure ~ of the
drawing, secondary flow channel 13 which extends between inlet 14
and outlet 15 is provided with a pair of hardened stainless steel
inserts having inner tapered cores, such as inserts 21 and 22.
The inner ends of the inserts 21 and 22 are in inwardly converging
relationship, one to another, forming the continuous secondary
flow channel 13, as indicated at 23 and 24. The inwardly
convering tapers may be expressed as converging and diverging with
respect to the fluid passing therethrough, and thereby forming a
Venturi with an open throat area as at 25 therebetween. The open
throat æone of the Venturi, as indicated, is disposed in a region
between the spaced apart inserts and defines generally an
injection chamber. The injection chamber is in direct
communication with injection port 17, thereby providing a means of
introducing fluid into the secondary flow channel 13 as defined by
segments as at 23 and 24.
As indicated, the injection chamber is in the form of a
generally annular enclosure, and is preferably arranged coaxially
with the secondary flow channel. The injection chamber has an
axial length which is, of course, substantially coextensive with
the length of the Venturi throat. With respect to the dimensional
relationships, the ratio of the cross-sectional area of the
annular chamber to that of the secondary flow channel at the
smaller end of the tapered area is approximately 10:1.
Furthermore, the ratio of the axial length of the injection
chamber to the diameter of the secondary flow channel at the
smaller end of the taper is approximately 2:1. By way of design
configurations and constraints, it has been found that the ratio
of the cross-sectional areas of the annular chamber to that of the
secondary flow channel is the more important.
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~ s has been indicated, the injector valve of the preGent
inventioll is preferab]y fabricated from hardened stainless. For
most flow arrangements, particularly for a valve deliveriny
approximately 4 to 5~ gallons per minute of diluted or working
solution at a pressure of approximately 100(, arid 1100 psi at
200F., a diameter for the taper channel .t the converged or
smaller end is in the range of approximately 0 035 inch for a flow
rate of 4 gpm and 0.040 inch for a flow rate of 5 gpm, it being
generally important that this dimension not be exceeded
substantially for these design and capacity objectives and goals.
Additionally, it is generally desired that the diameter of the
primary jet or primary flow channel be smaller than the diameter
of the secondary ~et or secondary flow channel by approximately
0.004 inch.
The primary flow channel, as indicated, is cylindrical and
of uniform diameter through its length. Also, it is desired that
the surfaces of the primary and secondary flow channels are smooth
and free of burrs or other anomalies, and that all entry and
discharge ports to the primary flow channel have the radius as
specified above. Conformance to these specifications thus reduces
or eliminates the tendency of the heated aqueous fluid to flash,
particulariy at temperatures of 200F.
It will be appreciated, of course, that those s~illed in
the art may depart from the specific design arrangements set forth
herein without departing from the spirit and scope of the present
invention.
What is claimed is:
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