Effluent treatment apparatus and method of operating same

An effluent treatment apparatus adapted for conditioning an effluent stream within a treatment zone is comprised of an injection system which includes at least one injection nozzle having a flexible discharge tube with an effective length at least equal to the characteristic wavelength for flexural resonant vibration thereof when pressurized fluid issues therefrom. The injection nozzle(s) preferably include(s) a length of elastomeric tubing as the discharge conduit, capable of providing a high flow rate of a conditioning agent to the treatment apparatus while delivering same in a relatively finely divided state. The conditioning agents may be delivered to a treatment zone within the apparatus in a generally concurrent, generally countercurrent, or generally transverse direction with respect to the flow of effluent to be conditioned. A recirculating system for the conditioning agent may be employed.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates, generally, to effluent treatment apparatus 
for conditioning an effluent stream and, more especially, to effluent 
treatment devices such as air treatment apparatus where a conditioning 
agent is caused to interact with an effluent stream in order to condition 
the same prior to discharge to the ambient. Broadly speaking, the present 
invention may be used to good advantage for the "conditioning" of a "fluid 
effluent" by treatment with a "fluid conditioning agent" to "alter" the 
effluent, as defined more particularly herein. 
2. Description of the Background Art 
Numerous, diverse types of treatment apparatus have been devised over the 
last several decades for the conditioning of effluent streams, and 
particularly gaseous effluent streams, generated during industrial 
processes. A principal impetus for the development and use of such devices 
has arisen as a consequence of environmental conscientiousness in an 
effort to abate pollution. Thus, myriad designs have been proposed for the 
classification of particulate, the elimination of toxic, noxious or 
malodorous constituents, or the alteration (actual or perceptual) of the 
constituents of an effluent before it is released to the atmosphere. 
Experience has shown that the need to meet ever-increasing standards 
imposed upon those who must discharge an effluent stream to the atmosphere 
has resulted in the need to resort to very complicated and hence expensive 
machinery. 
Various types of devices have been utilized to classify, segregate, or 
otherwise remove particulate material from a gaseous effluent stream. 
Conventionally, cyclone separators, electrostatic precipitators, so-called 
"bag houses" and plenum scrubbers have been employed for this task. Each 
type of device offers some advantage over the others but each has 
important limitations from either operational or cost-effectiveness points 
of view. 
Conventional cyclone separators work fairly well for the classification of 
particles having nominal sizes greater than about 25-30 microns. As the 
particulate to be removed falls within progressively lower size ranges, 
the effectiveness of a conventional cyclone separator falls off 
precipitously. Typically, for particles less than about 10-15 microns, a 
normal cyclone separator is found to be virtually ineffectual. 
Some have attempted to improve the ability of a cyclone to classify smaller 
particulates by the injection of fluid agents within the treatment zone of 
the device. The normative wisdom in this regard indicated that the fluid 
would effectuate an increase in the mass of smaller particulate thereby 
increasing the apparent size thereof insofar as classification is based 
upon centrifugal separation which, in turn, is directly related to the 
mass of the particulate to be classified. But, such prior attempts have 
normally diminished the overall operational efficiencies of the cyclone 
since the fluid injection has resulted in a diminution in field energy of 
the vortical flow of effluent-entrained particulate. By and large, 
therefore, there has been no development of commercially-acceptable wet 
cyclone devices. 
Electrostatic precipitators are viewed to work very well for removing small 
particulate from an effluent gas stream. Nonetheless, complete commercial 
integration of electrostatic precipitators as a uniform mode of air 
treatment to remove particulate is unlikely to occur since these devices 
are quite expensive and, thus, cost-prohibitive for many applications. To 
a lesser extent, but equally applicable, are the sometimes prohibitive 
costs involved in the installation of bag houses. 
Another approach for particulate removal is by means of a plenum scrubber. 
These devices rely upon the expansion of the effluent stream by 
introducing the flowing stream into a large chamber. The accompanying 
pressure drop tends to strip particulate from the effluent. Normally, 
fluid treatment agents are caused to pass in counter-current relationship 
vis-a-vis the direction of effluent flow. These devices are fairly 
efficient within fairly confined limits. 
Oftentimes, it is mandatory to remove not only particulate but also to 
remove or treat undesirable fluid or gaseous components entrained within 
an effluent stream. Customarily, regardless of the device employed for 
conditioning the effluent, suitable chemical agents are included within a 
fluid caused to contact or otherwise interact with the effluent. Gases may 
be reacted for removal or adsorbed or absorbed on or within a liquid 
treatment agent. Fluids may likewise be reacted, mixed, coagulated, or 
otherwise altered sufficiently to effectuate removal from the effluent. 
A persistent difficulty heretofore experienced in respect of the injection 
of fluid treatment agents within an air treatment apparatus results from 
limitations of the fluid injection devices employed. Quite routinely, 
fluid treatment agents, which usually must be finely dispersed to be 
optimally effective, are introduced via sintered nozzles having relatively 
small fluid passages. Other approaches, which attempt to minimize the need 
to use these fairly expensive sintered nozzles, nonetheless typically 
require discharge orifices of relatively small size in order to insure 
adequate atomization or dispersion of the fluid treatment agent. Virtually 
all such approaches result in the use of fluid injection nozzles highly 
prone to plugging if even very small sized foreign particulate finds its 
way within the fluid distribution system. This has all but eliminated the 
ability to use conventional filtration as a means for permitting 
recirculation of treatment fluid. Thus, the approach typically employed is 
to meter as best as possible the theoretical, optimum amount of treatment 
agent for reaction with the components in the effluent to be removed 
without including any excess. While this may seem fine on paper, in a 
plant many problems may be faced. If less than an appropriate amount of 
agent is injected into the air treatment apparatus, there will be 
incomplete reaction with the constituents to be removed and, accordingly, 
discharge of untreated effluent. If one attempts to compensate to insure 
virtually complete reaction, there is typically added an excess of agent 
which cannot be recovered and reused, contributing to an increased cost of 
operation and, perhaps, contributing to other sources of potential 
pollution since the remaining active components usually cannot simply be 
discharged to a sewer system. 
Insofar as the present invention advantageously merges the concepts of 
certain prior art nozzles, adapting same specifically for use in 
conjunction with effluent treatment apparatus to overcome operational 
problems of the nature aforesaid, some background on the characteristics 
of these nozzles is appropriate. The class of nozzles involved are those 
which dispense a pressurized fluid, typically a liquid, through a flexible 
tube. As pressurized fluid flows through the tube and discharges 
therefrom, a reactionary force is felt within the tube wall. By carefully 
mating the wave mechanics of the flowing fluid with the mechanical 
properties of the flexible conduit, a standing or resonant flexural 
vibrational wave may be established in the tube itself. 
This phenomenon has been recognized in various prior art devices where the 
flexural vibration of a tube is employed to some beneficial end. For 
example, irrigation or lawn sprinklers have been devised which rely on an 
oscillatory motion of a flexible tube when pressurized water discharges 
therefrom. Exemplary of such devices are those disclosed in U.S. Pat. Nos. 
3,030,031 and 2,930,531. This general principle has also been applied to 
the atomization of a liquid, and a representative device for this purpose 
is disclosed in U.S. Pat. No. 3,123,302. Other nozzles where a spray is 
created by conveying a pressurized fluid through a flexible tube are 
disclosed in U.S. Pat. Nos. 2,417,222 and 2,758,874. The latter of these 
two patents is further noteworthy insofar as it discloses a means for 
controlling the spray by including an outer sleeve on the flexible tube 
which may be slid along the length thereof. 
To date, the art has yet to appreciate that the general concept behind 
these oscillatory-type nozzles may be adapted to develop a nozzle which 
may be utilized in effluent treatment apparatus to overcome the serious 
limitations existing in these devices. Furthermore, the art has failed to 
appreciate that by suitable adaptation of such nozzles, the overall 
operational characteristics of many standard air pollution control devices 
may be materially enhanced. 
SUMMARY OF THE INVENTION 
The present invention advantageously provides a means for injecting fluid 
agent(s) within an effluent treatment apparatus for conditioning an 
effluent stream, whether the same be gaseous, liquid, a combination 
thereof and/or one having sold or semi-solid constituents entrained 
therein. By suitable design, the operational efficiencies of a cyclone 
separator may be materially enhanced thereby rendering this class of 
device capable of classifying sub-micron particulate. The present 
invention may also beneficially be employed for the processing of effluent 
within a plenum scrubber, a packed bed scrubber, or other similar device 
where chemical conditioning agents are injected to treat an effluent 
stream. A further benefit follows from an advantage achieved by the 
present invention which permits a simple recirculation loop to return 
excess chemical conditioning agents from the effluent treatment apparatus 
to the injection system therefor without the need to undertake elaborate 
filtration. In sum, the present invention advantageously eliminates many 
significant problems of prior art treatment apparatus while concomitantly 
increasing the operational efficiencies of many such devices. 
These and other advantages are provided by utilizing a fluid injection 
system which comprises at least one injection nozzle having a flexible 
discharge tube with an effective length at least equal to the 
characteristic wavelength for flexural resonant vibration thereof when 
pressurized fluid issues therefrom. The flexible discharge tube is 
preferably an elastomeric discharge tube and, most preferably, a silicone 
rubber discharge tube. Whereas prior art nozzles have typically been 
limited to flow rates ranging from a fraction of a gallon per hour to not 
more than about ten gallons per hour, a nozzle in accordance with the 
present invention may typically issue from one to fifteen gallons of fluid 
conditioning agent per minute, and may readily be scaled-up to achieve 
flow rates in excess of 100 gallons per minute, thereby materially 
enhancing the ability to inject an excess of treatment agent within the 
apparatus to insure sufficient quantities are present for complete 
reaction with any constituent desired to be removed or otherwise altered. 
The design of the fluid injection nozzles of the present invention 
includes fairly large fluid passages which are not prone to plugging, 
whereby excess treatment fluid injected within the apparatus may be 
recirculated. The recirculation system, itself, may be fairly simple in 
construction insofar as there is typically no requirement for elaborate 
filtration components. Thus, in one aspect of the present invention, a 
simple settling reservoir is interposed in the recirculation loop. The 
design immediately aforesaid also contributes to a significant decrease in 
power demands for the circulation/recirculation of conditioning fluid by 
eliminating the need for high pressure pumps and the like heretofore 
required for fluid distribution. 
In one facet of the present invention, a plurality of fluid injection 
nozzles are disposed within the treatment zone of a cyclone proximate the 
location for the vortical flow path of an effluent to be treated therein. 
Preferably, one or more arrays of such nozzles are disposed in a generally 
vertical orientation for the injection of fluid in a direction principally 
concurrent with the vortical flow path. This, along with the ability to 
inject substantial quantities of liquid agent, materially enhances the 
operational efficiencies of a conventional cyclone scrubber by, e.g., 
adding energy to the vortical field energy whereby the effective limits of 
applicability of these devices may be extended down to the sub-micron 
range of particulate removal. 
In another aspect of the present invention, liquid treatment agents are 
caused to issue from the flexible discharge nozzles into a plenum 
scrubber, wherein injection occurs in a direction generally countercurrent 
to that of effluent flow. In another preferred mode of operation, fluid 
may be injected transverse the flow of effluent proceeding through a 
treatment chamber. In yet another approach, fluid may be injected within a 
packed-bed scrubber far in excess of that theoretically required for 
complete reaction and excess, unused agent recirculated in the general 
manner aforesaid.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention relates, generally, to effluent treatment apparatus 
for conditioning an effluent stream and, more especially, to such 
apparatus wherein a fluid treatment agent capable of performing the 
conditioning of the effluent is caused to contact or otherwise interact 
with the same. In its broadest aspects, the apparatus of the present 
invention may be widely adapted for designing, modifying or retrofitting 
all varieties of effluent treatment devices which may employ the benefits 
of fluid injection, and particularly liquid injection, within the 
treatment zone where an effluent is conditioned. Along these lines, the 
term "conditioning" as used herein is meant to connote a chemical or 
perceptual alteration and/or the classification of the constituents 
comprising a fluid stream, particularly a gaseous stream, and most 
particularly a gaseous effluent stream containing noxious, toxic, and/or 
malodorous components in fluid and/or solid form. Accordingly, this term 
(conditioning) is intended to comprehend the addition to, removal from or 
modification of any constituent within an effluent. A principal objective, 
in this vein, is the removal and/or treatment of undesirable solid, 
liquid, and/or gaseous components from or within an effluent generated in 
an industrial process in order to render the same fit for discharge to the 
atmosphere. Thus, "effluent" or "fluid effluent" will be used to describe 
a stream which is a fluid or one having the attributes of a fluid (e.g., 
fluidized solids or slurry) within which may be contained or entrained 
solid or semi-solid matter along with gases and/or liquids destined for 
removal or conditioning treatment. It is also intended that the 
conditioning process includes the option of adding suitable odorants, 
deodorants or reodorants to the airstream should that be desired. With 
these thoughts in mind, the effluent is conditioned by contacting or 
interacting it with a "fluid conditioning (or "treatment") agent", by 
which term it is intended to connote an agent which is or has the 
attributers of a "fluid" capable of effecting a conditioning process. 
Hence, while the invention will now be described with reference to certain 
preferred embodiments adapted for use within the aforementioned contexts, 
those skilled in the art will appreciate that such a description is meant 
to be exemplary and not limitative. 
Referring to the figures of drawing, in all of which like parts are 
identified with like reference numerals, FIGS. 1 and 2 diagrammatically 
illustrate an air treatment apparatus in accordance with the present 
invention, designated generally as 10. Those skilled in the art will 
recognize the apparatus 10 to be based generally upon a conventional 
cyclone configuration. Thus, the air treatment apparatus 10 includes a 
somewhat conical chamber identified generally as 12 having a treatment 
zone 16 and an apical collection zone 18. An effluent inlet duct 20 
introduces effluent within the chamber tangentially with respect to the 
sidewalls thereof, designated 22. Accordingly, the effluent is caused to 
traverse a vortical flow path, designated generally as 24, within the 
treatment zone 16. As is generally conventional, the circulation of 
effluent in the vortical flow path 24 causes the classification of 
particulate by virtue of the centrifugal forces (or field energy of the 
circulating effluent) developed in the spiralling, circular flow path. As 
the forces affecting separation are proportional to mass and acceleration 
of the particulate, the heavier components are flung outwardly to the 
sidewall 22 or proximate the interior surfaces thereof and thence fall, or 
are otherwise directed, to the apical collection zone 18. Effluent 
stripped from particulate proceeds upwardly in a tighter, somewhat 
cylindrically spiral path 26 along a generally vertical discharge axis and 
exits the cyclone via duct 28. 
Thus far, the description of the cyclone 12 is coincident with the 
operation of similar, prior art cyclone devices. These devices have met 
with considerable operational limitations in use insofar as the same have 
generally been incapable of removing particulates having a size much below 
about 25-30 microns. The air treatment apparatus 10 of the present 
invention, however, extends the range of efficient separation, permitting 
the classification of micron or sub-micron size particles from effluent 
conducted th.rough the zone 16. 
The ability to classify sub-micron size particles within the air treatment 
apparatus 10 is achieved, in one facet of the present invention, by means 
of a fluid injection system designated generally as 30. The fluid 
injection system 30 is comprised of a conduit 32 leading from a reservoir, 
identified generally as 34 which houses a fluid conditioning agent for 
injection within the apparatus 10, to a plurality of fluid injection 
nozzles designated generally as 36. Each fluid injection nozzle 36, best 
viewed in FIGS. 6 and 7, is comprised of a nipple 38 in fluid 
communication with conduit 32 and a length of flexible tubing 40. The 
tubing is secured at one end to the nipple by, e.g., stretching it over a 
reduced stem 42 and affixing it securely by means of a clamp device 44. 
Fluid treatment agent delivered to the nozzle 36 may thus issue through 
the internal bore of flexible tube 40 passing from the discharge end 
thereof, designated generally as 46. By appropriate selection of material 
and coordination of the physical design of tube 40 with the flow 
characteristics of pressurized conditioning or treatment agent, it is 
possible to control carefully the spray geometry and discharge 
characteristics of issuing treatment agent. This is best explained with 
reference to FIGS. 3-5. 
FIG. 3 illustrates a length of flexible tubing T which is shown to 
oscillate in a generally sinusoidal wave as represented by both the full 
and phantom lines. The material from which the tube is selected is one 
best characterized as a flexible, resilient composition which will respond 
to the wave characteristics of fluid flowing therethrough and discharging 
therefrom. When pressurized fluid flows through and issues from the 
tubular member, the reactionary forces of fluid flow are coupled to the 
tube walls. It is possible to match the travelling wave characteristics of 
the fluid to a characteristic flexural standing wave of the flexible 
tubing to achieve a resonant flexural vibration as shown generally in FIG. 
3. The wave characteristics are governed by quite a number of variables 
which permit suitable tailoring of flow patterns and spray geometries by 
suitable selection of precise parameters. Those variables having a 
principal influence on flow patterns and spray geometries (beyond length 
of the tubing--which has the most dramatic effect as discussed below) are 
the material from which the tubing is made, its size in terms of inner and 
outer diameters and thus thickness, the pressure head on the fluid flowing 
therethrough and the volume flow rate thereof, ambient considerations such 
as temperature which will affect both the fluid properties and material 
properties of the tubing, and viscosity of the agent or fluid flowing 
through the tube. Tip geometry (e.g., blunt, angled, etc.) will also 
affect the spray geometry of a stream issuing from such a vibrating tube. 
Further variation may be achieved by application of a slight transverse 
constriction externally of the tube, that variation being influenced 
additionally by point versus line application of the constricting force. 
Thus, by appropriate alteration of one or more of these variables, flow 
patterns may be regulated. These latter considerations are best considered 
with reference to FIGS. 4 and 5 which show the cross-section and profile 
of varying spray geometries, respectively. 
The standing wave in the flexible tube is essentially one corresponding to 
a sinusoidal wave form. The points of minimized vibrational amplitude are 
termed nodes while those of maximized vibrational amplitude are known as 
antinodes. Depending upon the relationship of the discharge end of the 
tube to a given node or antinode, the pattern of spray issuing from the 
tube will vary from a straight stream to a fan to a cone, this last 
mentioned spray pattern corresponding approximately to a node. Thus, all 
other variables being held constant, cutting or otherwise dimensioning the 
flexible tube to have a length or effective length running between a node 
and an antinode permits for a variation in spray geometry from a cone to a 
fan to a stream. If the length of the tube, or its effective length, is 
greater than one complete wavelength, a compound pattern may be achieved 
which merges both, e.g., an overall conical-type oscillation with a flat 
fan. Consequently, all manner of spray variations may be achieved. 
FIG. 4 illustrates diagrammatically the cross-section of these varying 
spray patterns, where the outer trace A corresponds to a conical spray, 
the trace B an ovate fan spray, trace C a flatter fan spray, and trace D a 
stream. The same identifying letters are employed in FIG. 5 to show the 
progressively narrower profiles of these various spray geometries. Thus, 
each spray geometry will have a spray divergence angle .alpha., that angle 
being shown for only the conical trace A in FIG. 5, which becomes 
progressively smaller as the pattern moves from a conical spray to a 
stream. 
By way of example, in order simply to relate the manner in which a given 
tube will respond, a silicone rubber tube having a 1/4" inner diameter and 
a 3/4" outer diameter was cut to be approximately 7" long. Water under a 
pressure of about 60 p.s.i.g. was discharged through this tube at a flow 
rate between about 7 and 7.5 gpm. A resonant flexural wave was obtained 
and the spray pattern was generally conical. 
While it is noted above that one may alter the spray geometries by changing 
the length of the flexible tubing, the same result may be achieved for a 
given tube operating in a given environment by altering the flow 
parameters of liquid discharged therefrom. For example, fluid flow may be 
regulated to change the wavelength to be matched between fluid and tube 
and, where the tube length is physically held constant, its effective 
length may be lengthened or shortened in this way. Thus, all other factors 
governing vibrational resourdes being equal, there will be a 
resonant-effective pressure to achieve this mode of vibrational resonance 
and, once determined at a threshold, the pressure may be altered to alter 
the spray geometry. Another approach for controlling the spray geometry is 
by including a damping member, such as that identified as 48 in FIGS. 6 
and 7, exteriorly adJacent the tube 40. Positioning the damping member 
along the length of the tube 40 will alter its response to fluid flow and, 
consequently, adjust its effective wavelength to vary the spray pattern 
from, e.g., conical to fan. Hence, the sleeve 48 may be viewed as a tuning 
means for achieving a precise spray geometry. 
To varying extents, any flexible material will have a tendency to operate 
in the manner described above and, accordingly, may be adapted for use as 
the discharge tubing 40. For purposes of the present invention, the 
preferred materials are those meeting the American Society for Testing and 
Materials definition of "rubber" (ASTM D1566-62T). Most preferred are the 
elastomers, and within this classification the most preferable material is 
silicone rubber. 
As best viewed in FIG. 1, it is preferred to dispose a plurality of nozzles 
36 in a generally vertical array for injection of fluid treatment agent 
within the treatment zone 16. This may be achieved by piercing the 
sidewall 22 at various locations along its upper extent, as shown 
generally in full lines in FIG. 1, and passing the nipple 38 through the 
wall. Each location where a hole is pierced should then be sealed to 
maintain the integrity of the device. Optionally, the array may coincide 
with a separate pipe identified as 32' and shown in phantom lines in FIG. 
1, the pipe 32' having a number of nipple fittings 38' and nozzles 36' 
disposed along its vertical rise. 
Another array of fluid injection nozzles which may used to good advantage 
in a cyclone configuration is shown in FIGS. 8 and 9, where like parts are 
identified with like reference numerals as respects the embodiment of 
FIGS. 1 and 2. In FIG. 8, multiple arrays of fluid injection nozzles 136 
are disposed about the upper periphery of treatment zone 16. A fluid 
distribution conduit 132a communicates with a first vertical array of 
fluid distribution nozzles designated generally as 136a disposed 
circumferentially adjacent the upstream side of inlet duct 20. The 
distribution conduit continues with a generally horizontal leg 132b 
terminating in a downwardly depending leg 132c which communicates with an 
array of nozzles designated generally 136c, preferably disposed 
diametrically from the array 136a. Optionally, the leg 132b may have 
associated therewith depending fluid distribution conduits (not shown) for 
supplying pressurized fluid conditioning agent to diametrically opposed 
arrays 136b, illustrated in phantom lines in FIG. 9. Where these multiple 
arrays of fluid injection nozzles are employed in the general form shown 
in FIGS. 8 and 9, it is preferred that the same be spaced generally 
equiangularly about the circumference of treatment zone 16, although this 
is not a hard and fast requirement to achieve the benefits of the present 
invention. It is also preferred that the array terminate at its lower 
extent approximately equal to or only slightly above the lowermost 
projection of exit duct 28 within the treatment zone 16; although, again, 
this requirement may be subject to relaxation. 
Regardless of the manner in which the fluid injection nozzles are 
physically associated with the cyclone 12, the same are provided to inject 
fluid conditioning agent within the treatment zone in a direction 
generally concurrent with the vortical flow path of effluent, identified 
as 24. In this manner, and when operating in the most preferable spray 
mode to yield a conical pattern, the flowing fluid agent will augment the 
effluent flow and enhance its energy while concomittantly saturating or 
otherwise reacting with particulate for removal thereof. This is best 
visualized by imagining a spray axis for each nozzle which will coincide 
with the line identified "X" in FIGS. 4 and 5. As can be seen with 
reference to FIGS. 4 and 5, the spray pattern expands in all directions 
about the spray axis, coinciding with the spray divergence angle .alpha.. 
But, the gross or principal direction of flow follows the axis and it is 
generally preferred to orient the spray axis so that it has a major 
component concurrent with the vortical flow path 24. The portion of the 
spray outwardly disposed from the spray axis toward the sidewall 22 will 
keep that sidewall free from particulate buildup while the portion of the 
spray inwardly proximate the spray axis and vortical flow path will 
usually insure adequate saturation of particulate entrained in the 
swirling effluent. 
Under certain operational conditions, it may be necessary or desirable to 
cause the spray or a portion thereof to have a somewhat transverse 
orientation for increased penetration of liquid treatment agent within the 
vortical flow path 24. One manner for achieving this effect is to orient 
the nozzles 36 in a given vertical array in two sets, where each "set" has 
at least one nozzle, with differing orientations. Alternating nozzles may 
lie in the same set whereas successive nozzles may lie in different sets. 
For the simplest case, of two nozzles, each defines its own "set." For 
three or more nozzles, every other nozzle will preferably lie in a given 
set; for example, the first set of nozzles may be comprised of the first, 
third, fifth, etc. nozzles while the second set may be comprised of the 
second, fourth, sixth, etc. nozzles. The two sets thus defined may have an 
angular displacement measured horizontally, the magnitude of this spray 
separation angle varying depending upon the extent to which it is 
necessary or desirable to create a transverse spray component. Thus, the 
angle may range from zero to about 90.degree.. Exceeding 90.degree. will 
in most instances be counter-productive as the spray will rob energy from 
the vortical flow path in an amount greater than the added energy provided 
by the introduced fluid; thereby defeating the advantage of centrifugal 
classification. As the angle decreases from about 90.degree., less and 
less energy will be sapped from the flow stream and, in fact, as the angle 
approaches zero the added energy will become more and more pronounced. At 
some angular displacement, there will occur an optimum cross-over between 
the tolerable energy withdrawal from the system versus the maximum liquid 
saturation of the effluent stream. This cross-over point will vary from 
installation to installation and, for a given installation, will vary with 
the effluent introduced within the treatment apparatus 10. Accordingly, it 
is not realistic to put absolute parameters on this feature of the present 
invention, the precise angu1ar disp1acement being best determined on a 
case-by-case basis given the demands of a given operation. However, in 
most cases, this separation angle will be less than 45.degree., and in 
many cases less than 20.degree., to achieve the desired balance. 
The foregoing aspect of the present invention may be visualized in a 
mathematical sense with reference to the geometric representation of FIG. 
10. As noted generally above, each spray pattern, regardless of its 
profile, will have a spray axis X. Two axes are represented in FIG. 10 by 
the vectors A.sub.1 and A.sub.2 which, for illustrative purposes, may be 
considered the spray axes for a conical pattern identified A in FIGS. 4 
and 5. The vector A.sub.1 corresponds to a spray axis for a given nozzle 
where the axis lies tangential to the vortical flow path 24 proximate the 
location for the nozzle. Since it is tangential, this mode may be defined 
as one where the entire spray axis vector lies generally concurrent with 
the direction of flow of the swirling effluent within the treatment zone. 
This represents a mode where energy from the fluid spray is additive to 
the field energy of effluent flow at a maximum. The spray axis vector 
A.sub.2 is angularly displaced from vector A, by the angle .beta., which 
is the spray separation angle between the two fluid streams issuing from 
nozzles which are displaced horizontally. The vector A.sub.2, departing 
from the tangential orientation of vector A.sub.1, will thus cut the arc 
of the effluent flow path and the spray represented thereby will impinge 
more directly upon and penetrate more deeply within the vortical flow 
thereof (i.e., the sense of vector A.sub.2 will lie along a chordal 
segment in a horizontal plane through the flow path). The vector A.sub.2 
may be represented by the two components "a" and "b" in FIG. 10; the 
component "a" lying in the tangential direction and the component "b" in a 
direction normal to the vortical flow path. As can be seen with reference 
to FIG. 10, the tangential component "a" is the principal component of the 
vector A.sub.2 and the energy represented by this vector thus contributes 
to the energy field of the swirling effluent, while the normal component 
"b" is the lesser component and will contribute to interference with 
effluent flow. When the spray divergence angle .alpha..sub.2 is then 
considered, it becomes apparent that there will be a force component 
countercurrent to the direction of flow of effluent within the treatment 
zone 16 which will diminish the field energy thereof. The benefits of 
employing the instant fluid distribution system of the present invention 
reside in part in the fact that the injected fluid contributes to the 
field energy of effluent within the treatment zone. Hence, it is 
preferable that any component countercurrent to the direction of vortical 
flow be at least balanced by a component concurrent therewith. Most 
preferably, there will always be a major component tangential to flow 
thereby boosting the same by adding energy to the field. Consequently, in 
most circumstances, the benefits of insuring penetration of fluid within 
the swirling effluent provided by an orientation such as that represented 
by vector A.sub.2 giving rise to a countercurrent component) will be more 
than balanced by the larger concurrent component of nozzles oriented to 
provide spray vectors such as A.sub.1, or even the major tangential 
component of a divergent vector such as that represented by the segment 
"a". This balancing of energy addition/flow saturation is achievable where 
the spray separation angle is less than 90.degree., preferably less than 
45.degree. and most preferably less than 20.degree.. Other options along 
these lines are discussed below. 
A particularly distinct advantage of the present invention over known 
techniques for the injection of fluid within a cyclone is the ability to 
inject considerably greater quantities of fluid treatment agent without 
waste and without contributing to the plugging and, thus, the disability 
of the entire system. In order to achieve a fine enough dispersion, and 
one which would not unduly sap the energy within the vortical flow path, 
most prior approaches have been confined to the injection of less than 
about a few (e.g., up to about 10) gallons per hour of liquid treatment 
agent. The present invention permits a considerably greater flow rate, and 
one increased by at least about one order of magnitude, insofar as a per 
nozzle flow of up to at least 15 gallons per minute is readily achievable 
in even small to medium size devices. Scaling up the size of the nozzles 
for use in large installations (e.g., cyclones employed in the mining 
industry) permits per-nozzle flow rates in excess of 100 gpm. The benefits 
realized by this aspect of the invention are multifold. First, the energy 
accompanying the injection of such vast quantities of fluid effectively 
augments the field energy of the vortical flow path as noted above. 
Maximum saturation of constituents within the effluent may also be 
achieved. And, these advantages are realized without fear of plugging 
since most small to medium commercial applications may use a flexible tube 
having an inner diameter on the order of about 1/8" or greater which will 
allow any particulate material to pass through the tube. And further, 
since the tube is flexible, it may distend to allow large or relatively 
large particles or agglomerations thereof to be forced through its 
interior. By virtue of these operational advantages, the present invention 
permits the incorporation of a simple recirculation system identified 
generally as 50 in FIGS. 1 and 2. Furthermore, the energy required to 
inject the fluid conditioning agents is considerably reduced by employing 
the instant system since there is no need to achieve the higher injection 
pressures necessary when, e.g., sintered nozzles are used. Rather, 
conventional pumps capable of delivering conditioning agent at about 60 
p.s.i.g. will noramlly be found entirely satisfactory. This, too, reduces 
the capital expenditure required for operation. 
The recirculation system 50 contributing to those advantages is comprised 
of a fluid conduit 52 leading from the apical collection zone 18 of the 
cyclone 12 to the settling reservoir 34. The fluid conduit 32 completes 
the circuit for the recirculation sytem. Thus, in a general sense, fluid 
treatment agent issues from the fluid injection nozzles 36 for 
conditioning the effluent circulating within the zone 16 and thereafter 
collects in the apical zone 18 along with any constituents removed from 
the effluent, whence they are directed via conduit 52 to the settling 
reservoir 34. As shown in FIG. 1, the conduit 52 enters the reservoir 
intermediate the height thereof through an inlet 54 proximate a baffle 56. 
Liquid, along with any particulate, passes downwardly and solids are 
permitted to settle near the bottom of the reservoir 34. Partially 
clarified conditioning agent may then be recovered by a dip tube 58 
projecting downwardly into the reservoir and recirculated to the fluid 
injection system 30 by means of a pump 60. As treatment agent is depleted, 
it may automatically be replenished within the reservoir 34 by means of a 
float/solenoid device 62, which senses the height of liquid within the 
reservoir and, when it falls below a predetermined level, actuates a pump 
for additions of liquid through conduit 64 from an auxiliary source (not 
shown). 
In operation, the air treatment apparatus 10 amalgamates the advantages of 
cyclone separation technology with wet scrubber technology, employing the 
benefits of each synergistically to yield an air treatment device which 
operates more efficiently than known cyclone separators. That is, the 
simplicity of a cyclone is carried forward for the treatment of effluent 
but its inherent limitations are overcome by the instant fluid inJection 
system which permits the classification of particulate far finer than the 
previous limits on a cyclone. And, the manner in which fluid is injected 
within the treatment zone enhances the separatory action of the device 
insofar as the fluid itself imparts greater energy to the field energy of 
the vortical effluent stream. These advantages are achieved as follows. 
An effluent stream is caused to enter the cyclone 12 via the tangential 
inlet duct 20, whereupon it is deflected about the inner periphery of the 
sidwall 22 and a vortical flow path 24 thereby established. The field 
energy of the vortical flow path 24 results in a centrifugal 
classification of particulates, which are cast to the outer region of the 
treatment zone. Concomittantly, fluid is injected within the treatment 
zone through the plurality of fluid injection nozzles 36 in FIGS. 1 and 2 
or 136 if the embodiment of FIGS. 8 and 9 is selected. It is most 
preferred to tune the nozzles so that a conical spray represented by the 
trace A in FIGS. 4 and 5 is achieved since this will provide optimum 
dispersion of fluid. The principal direction of fluid flow, represented by 
the spray axis shown diagrammatically in FIGS. 4, 5 and 10, is desirably 
generally concurrent with the vortical flow path (in a net sense, when the 
three-dimensioned nature of each spray is taken into account). That is, 
the fluid flow force will have a vector with a major or at least 
substantial component lying generally tangential to the flow path 24. 
Thus, the energy of the injected fluid will be additive with that of the 
vortical field energy thereby enhancing the overall separatory effects 
within the cyclone. Because a conical spray is most preferably employed, 
there will preferably be a spray component impinging upon the sidewalls 22 
which will beneficially wash away classified particulate which might 
otherwise build up at these locations and retard the swirling motion of 
effluent within the device. There will also preferably be a spray 
component impinging directly upon the moving effluent, penetrating the 
flow path to provide a greater interaction between swirling particulate 
and injected fluid. Optionally, depending upon the precise operating 
parameters of a given apparatus, these nozzles 36 or 136 may be disposed 
in two sets where one of the sets (having at least one nozzle) is, as 
noted above, displaced angularly along the horizontal to inject fluid more 
directly into the swirling effluent. This angle may range up to about 
90.degree., whereupon the displaced nozzle(s) will begin to inject fluid 
along a spray axis (representing the force vector of spray) generally 
normal to the vortical flow direction. Although this will tend to extract 
energy from the vortical field energy of swirling effluent, this 
orientation of nozzles will maximize fluid coverage within the treatment 
zone 16. In some situations this may be an entirely acceptable trade-off. 
In an effort to minimize the amount of energy sapped from the vortical 
field, one might use a reduced diameter nozzle for those oriented for 
greater impingement on the effluent stream (i.e., those geometrically 
represented by vector A.sub.2 in FIG. 10) in order to permit the benefits 
of greater penetration of fluid within the effluent while minimizing the 
interference factor. These are features which do not admit readily of 
projection from first principles, but guided by the knowledge provided 
herein, those skilled in the art may empirically refine this aspect of the 
invention to meet the exigencies of individual applications. 
The injected fluid within the air treatment apparatus 10 may be of any 
suitable composition to achieve an effective conditioning of the effluent 
entering duct 20. For some particulates, water may be sufficient. 
Optionally, a surfactant may be added to the water to improve the 
classification of certain types of particulate. It is also envisioned to 
include chemical reactants within the inJected fluid should it be 
necessary or desirable to treat the particulates to be classified; for 
example, to achieve neutralization of active constituents thereof. It is 
equally well envisioned to include conditioning agents which will 
effectively remove unwanted gaseous or liquid constituents of the incoming 
effluent stream. Such conditioning agents might be employed to react with 
these unwanted fluid constituents of the effluent in order to neutralize 
the same. Fluids can be absorbed or adsorbed within or upon appropriate 
conditioning agents added to the injected fluid. Likewise, liquids or 
semi-solids may be coagulated and/or agglomerated and then removed by 
normal centrifugal classification within the apparatus 10. dorants, 
deodorants or reodorants may comprise the injected fluid if necessary or 
desirable. In some circumstances, the fluid conditioning agent may be 
gaseous or include a gaseous constituent. Those skilled in the art, faced 
with the need to condition a given effluent stream are acquainted with 
suitable chemical compositions which will achieve the aforementioned 
results and can, guided by the principles set forth herein, select an 
appropriate mixture to that end. 
Effluent stripped of unwanted components or otherwise suitably conditioned 
within the treatment zone 16 may exit via the duct 28 and thence be 
discharged or routed for further treatment if necessary or desirable. 
Removed constituents along with fluid injected within the cyclone 12 will 
fall to the apical collection zone 18, whence the same may be routed to 
the settling reservoir 34. Solids, generally in the form of a sludge, 
semi-solids, and higher density liquids will settle to the bottom of the 
reservoir 34 and may be withdrawn periodically therefrom. Clarified 
treatment agent recovered from the cyclone and residing in the reservoir 
may be recirculated therefrom to the injection nozzles 36 for reuse. Thus, 
a continuous distribution loop is established. As the quantity of active 
treating agent is depleted through use, reaction, or withdrawal with 
settled sludge, fresh agent may be added via the conduit 64. 
A principal advantage achieved by the invention described herein is the 
ability to eliminate the need for elaborate filtration devices in order to 
realize the economic advantage of this recirculation; since any 
particulate or the like recirculated inadvertently with treatment fluid 
may easily pass the fluid nozzles without plugging. Furthermore, excess 
treatment fluid may be injected within the treatment zone 16 to insure an 
overabundance and, hence, a sufficient quantity of conditioning agent for 
complete reaction with or conditioning of the effluent stream. For 
example, it has been determined that single nozzle 36 having a silicone 
rubber tube 40 with an inner diameter of 1/4", an outer diamenter of 3/4" 
and a length of about 7" may readily pass about 7 gallons per minute of 
treatment agent (pressurized to 60 p.s.i.g.) in a fine conical spray. 
Increasing the dimension of the tube and/or the pressure head permits 
flows per nozzle in the 10-15 gpm range. Further upward scaling of the 
dimensions of the flexible tube and flow allows per-nozzle rates in excess 
of 100 gpm which may be used in very large applications where it is 
favored to employ a smaller number of high-capacity nozzles over a greater 
number of low-capacity nozzles. This compares with typical per-nozzle flow 
rates of less than about 10 gallons per hour and, more typically, less 
than about 3 gallons per hour, in prior art devices. 
As can be appreciated from the foregoing, all manner of conditioning may be 
achieved within the apparatus 10 in ways beyond the ambit of conventional 
cyclone scrubbers. Many of the same benefits can be realized by employing 
a similar type of fluid injection system in other conventional scrubber 
designs. These benefits are best explained with reference to FIGS. 11-13. 
FIG. 11 illustrates diagrammatically a plenum scrubber designated generally 
as 200. Scrubber 200 includes a rather large treatment zone 202 within 
which effluent is injected via ports 204. As effluent enters the treatment 
zone 202 there is a substantial accompanying pressure drop which tends to 
strip particulate from the effluent. The gaseous effluent passes upwardly 
for discharge through an exhaust vent 206. Some designs of plenum 
scrubbers such as the device typified in FIG. 11 also include a fluid 
injection system for introduction of fluid in a countercurrent 
relationship with that of rising gaseous effluent. The fluid injected will 
tend to retard any tendency for stripped particulate to become 
re-entrained within the gas stream and may also include conditioning agent 
for reaction with gaseous or liquid components of the effluent. But, as 
noted above, the injection nozzles heretofore employed have been severely 
limited in flow rate in order to achieve adequate fluid dispersion and, 
hence, recirculation of injected fluid has been all but eliminated as a 
viable mode of operation. Accordingly, fluid treatment agent, which may be 
comprised of relatively expensive components, could not economically be 
added in excess since the quantity injected normally was merely routed 
away from the device for disposal. Further along these lines, disposal 
itself may have been problematic as the treatment agents themselves, 
designed to abate air pollution, become water pollutants in their own 
right. 
These drawbacks have been alleviated in large measure by the incorporation 
of a fluid injection system 208 which includes a fluid distribution 
conduit 210 and a plurality of fluid injection nozzles 212 generally 
identical to the nozzle 36 shown in FIGS. 6 and 7. Fluid conditioning 
agent under pressure may be discharged through the nozzles 212 causing, 
upon appropriate balancing of the variables enumerated above, a flexural 
resonant vibration of the flexible discharge tube of each nozzle. The 
dispersion of conditioning agent provides all of the advantages of prior 
approaches to the injection of fluid within a plenum but permits the 
recirculation of treatment agent as is the case in respect of the air 
treatment apparatus 10. Thus, fluid and removed constituents from the 
effluent are permitted to collect in a lower collection zone 214 from 
which the same may flow via conduit 216 to a recirculation system such as 
that identified as 50 in FIGS. 1 and 2. Collected treatment agent and 
captured materials from the effluent are segregated as described above, 
and clarified treatment agent recirculated to the fluid inJection system 
208 for reuse. Thus, an overabundance of treatment agent may be 
efficiently injected within the plenum scrubber and the unreacted, usable 
portion thereof recirculated for further treatment. 
FIG. 12 diagrammatically illustrates yet another type of plenum scrubber, 
designated generally as 300. The scrubber 300 includes a central plenum 
treatment chamber 302 having an effluent inlet 304 near its upper reaches 
and an outlet 306 leading from the lower portion of the plenum 302. In the 
embodiment shown in FIG. 12, a fluid injection system, designated 
generally as 308, is included for the introduction of conditioning fluid 
within the plenum 302. The fluid injection system 308 is comprised of a 
distribution conduit 310 which communicates with an array of injection 
nozzles 312 virtually the same as the nozzles 36 described above. A 
separate nozzle 313, again like nozzles 36, is disposed proximate the 
juncture of duct 306 and chamber 302. Effluent entering the plenum 302 is 
sprayed initially by nozzle 313 and, as the effluent then proceeds 
downwardly within the plenum, fluid agent is sprayed transversely across 
the path by means of the remaining nozzles 312. This insures full contact 
of fluid conditioning agent with effluent to be conditioned as the same 
traverses the apparatus 300. 
The air treatment apparatus 300 is configured principally for the removal 
of liquid or gaseous components from the effluent entering via port 304. 
In some cases, it may be advantageous to associate a device such as this 
one with a cyclone separator such as the one illustrated in FIGS. 1 and 2 
herein. Thus, the cyclone will remove particulate and treat or pretreat 
fluid and/or gaseous components in the effluent from an industrial 
process, and that partially or pre-treated, but particulate-stripped, 
effluent have the last vestiges of fluid and/or gaseous contaminants 
removed by treatment in scrubber 300. Should that be the mode of 
operation, the fluid injected within plenum 302 may be recovered and 
recirculated through the recirculation loop 50 associated with the cyclone 
10, thereby achieving the economic benefits of recirculation noted above. 
When the apparatus 300 is to be operated independently of any other air 
treatment equipment, recirculation may be achieved simply by the fluid 
loop designated generally as 314 in FIG. 12. This loop comprises a conduit 
316 leading from the lowermost portion of the plenum 302, where treatment 
fluid will collect, to a pump 318 which recirculates recovered treatment 
agent through a valve 319 to the distribution conduit 310. In this 
fashion, a closed loop for treatment agent is provided. Suitable taps may 
be provided for withdrawing spent fluid and replenishing the conditioning 
agent as may be required or desired by the operator thereof. 
Another highly preferred mode of operation for the apparatus 300 involves 
the injection of fresh treatment or conditioning agent through only the 
nozzle 313, while the bank of nozzles in array 308 are employed in a 
simple recirculation loop. More specifically, nozzle 313 is preferably 
configured for the metered distribution of liquid treatment agent within 
the chamber 302, contacting the incoming effluent entering the chamber 
through duct 304 and misting downwardly within the chamber. Liquid 
treatment agent which collects near the bottom of chamber 302 is then 
simply recirculated via the loop 314 and is sprayed transversely acros the 
effluent path through the nozzles 312. An overflow 320 may be provided for 
withdrawing treatment agent as its activity becomes depleted during the 
conditioning process. The vertical height of the overflow is preferably 
above that for the recirculation leg 316, in which case a simple 
steady-state operation may proceed. Alternately, the overflow 320 may be 
valved and excess agent tapped periodically so that its level does not 
rise sufficiently high to interfere with effluent attempting to exit duct 
306. 
When operating in the condition immediately aforesaid, the nozzle 313 need 
not be one including a flexible discharge tube but may be of any 
conventional design since further, maximum saturation may be achieved 
through the array of nozzles 312 which will be formed like the nozzles 36 
described above with reference to FIGS. 6 and 7 and recirculation will 
occur only through these latter nozzles. The principal purpose of nozzle 
313 is the misting injection of fluid to maintain a balance between the 
input of agent for conditioning and withdrawal of depleted agent through 
overflow 320. Nonetheless, it is preferred that nozzle 313 be a metering 
or mixture-type nozzle including a flexible discharge tube; suitable 
constructions therefor being described more fully hereinbelow with 
reference to FIGS. 14-19. 
The apparatus 300 depicted in FIG. 12 is also shown to include a nozzle 322 
disposed in the inlet port 304. The nozzle 322 is optionally provided and, 
when present, will be one having the general construction shown in FIGS. 6 
and 7. The nozzle 322, or a plurality of same, may be disposed along ducts 
joining various treatment apparatus or joining a given apparatus with the 
vessel or device within which the effluent has been generated. Nozzles 
disposed within the duct work, such as 322, thus permit en-route treatment 
of effluent or pretreatment thereof. Where these en-route nozzles are 
employed within the duct work, it is particularly advantageous to 
incorporate some means of transverse constriction across the flexible tube 
thereby permitting a considerable reduction in physical length of the 
flexible member while nonetheless maintaining a sufficient effective 
length allowing for resonant flexural vibration. These features, noted 
generally above, are described more fully below with reference to the 
embodiment of FIGS. 20 and 21. En-route treatment may also be a desirable 
goal where it is less efficient to attempt treatment of multiple 
constituents within the effluent in a single chamber; for example, when 
the necessary conditioning agents for removing different components are 
themselves interactive and perhaps antagonistic to thorough removal. Thus, 
a stream having a first constituent for treatment can be treated en-route 
by application of a suitable conditioning agent and the partially or 
pretreated effluent then treated in, e.g., chamber 302 for complete 
conditioning. Other treatment reactions may proceed more efficiently if 
the effluent first has admixed therewith a constituent which may act 
catalytically when subsequent conditioning agent is then dispersed within 
the effluent. In this case, the use of en-route injection through nozzles 
such as 322 may incorporate the catalytically active component and, when 
the effluent is then treated within chamber 302, nozzle 313 may inject the 
desirable reactant. Other situations requiring or benefiting from en-route 
treatment may occur and, guided by the foregoing, those skilled in the art 
may advantageously incorporate this feature of the present invention. 
FIG. 13 diagrammatically represents yet another variety of air treatment 
apparatus, designated generally as 400. The apparatus 400 includes a 
central treatment zone designated generally as 402 through which effluent 
may be routed via upper and lower ducts 404. The central treatment zone 
402 includes a plurality of chambers 406 separated by packed beds 408. 
Thus, those skilled in the art will recognize the device 400 as a variety 
of packed bed scrubber. 
Fluid is injected within the treatment zone 402 by means of a fluid 
injection system designated generally as 410. The fluid injection system 
is comprised of a fluid distribution conduit 412 with which communicate a 
plurality of nozzles 414 like those identified 36 in FIGS. 6 and 7. Fluid 
treatment agent injected within, preferably, the open zones 406 will 
contact moving effluent and will also saturate the packing in zones 408. 
The packing components, which may be comprised of spherical elements, will 
thereby bear on their outer surfaces active treatment agent for 
presentation of a high surface area to effluent flowing therethrough. 
Thus, effluent conducted through the treatment zone 402 will be caused to 
pass in contact with a mist of conditioning agent within the open zones 
406 and traverse a tortuous path through the packing in zones 408 also 
having associated conditioning agent for intimate contact and treatment of 
the effluent. 
In some cases, it may be desirable to associate a packed bed scrubber such 
as the scrubber 400 with a wet cyclone separator such as the one described 
above with reference to FIGS. 1 or 8. Packed bed scrubbers can be 
relatively sensitive to particulate entrained within the effluent to be 
processed thereby, since the particles will tend to lodge within the 
interstices of the packing components. Efficiency is accordingly 
diminished and, consequently, the packing must be periodically cleaned to 
remove these contaminating materials or replaced altogether. Pretreatment 
within a cyclone such as air treatment apparatus 10 disclosed herein will 
eliminate that particulate contamination thereby benefitting the 
subsequent treatment for removal of gases and/or liquids by the packed 
scrubber 400. Should that be the case, fluid injected within the scrubber 
400 may be recovered and routed to the recirculation loop 50 associated 
with the device 10 shown in FIGS. 1 and 2. If the packed scrubber 400 is 
to be operated independently, a recirculation loop designated generally as 
416 may be utilized. In that event, the recirculation loop 416 can be the 
same as that identified at 314 in FIG. 12, and needs no further 
elaboration here. 
Irrespective of the precise design of the air treatment apparatus within 
which fluid is injected via a nozzle of the present invention, that fluid 
may be introduced in numerous spray configurations best suited for the 
application at hand. In most instances, it will be preferred to inject 
fluid in a conical spray working within the first wavelength of the 
characteristic flexural wave of the discharge tube employed. This conical 
spray will tend to provide a good dispersion of fluid in a uniform 
pattern. However, in some applications it may be desired to use a flatter 
fan configuration or an intermediate ovate fan. In yet other instances, it 
may be advantageous to operate within the second or a longer wavelength to 
achieve a compound spray geometry. 
Looking to the flexible tube itself, one may incorporate a tuning sleeve 
such as that depicted in FIGS. 6 and 7 in order to achieve the precise, 
desirable spray pattern. As opposed to this sleeve member for tuning, a 
clamp (such as a wire clamp) may be used. In certain applications, it has 
been found desirable to assemble the flexible tube from a pair of 
individual tubes of suitable inner and outer diameters so that one may be 
pulled within the other to form a type of composite. This will tend to 
improve the strength of the tube without causing the need to resort to 
large size tubing. It has been determined that this composite approach may 
be preferable in certain applications where silicone tubing is the 
selected nozzle material since considerable increase in wall strength is 
achieved without unduly damping the inherent wave properties. 
FIGS. 14-21 illustrate a number of modifications to the flexible tube used 
as the fluid discharge tube for the nozzles employed in conjunction with 
the present invention. These variations range from adaptations to permit 
mixing of diverse fluids to those permitting adjustments of the mode of 
flexural resonant vibration. 
FIG. 14 shows a segment of flexible tubing 500 comprised of two tubes 502 
and 504 joined tangentially along a linear axis 506 to yield a stacked 
compound tube. Each of the tubes 502 and 504 includes an inner channel, 
508 and 510 respectively, through which fluid may flow. The juncture 506 
between the two tubes may be formed adhesively or by autogenous fusion by 
use of a suitable solvent for the material from which the tubing is made. 
The juncture may be continuous or discontinuous, in the sense that the two 
tubes may be secured intermittently along the common tangent with points 
or lines of attachment separated by unjoined segments. Further, a third 
(or further yet a fourth) tube might comprise the compound tube 500 by 
joining the same in the same fashion. 
Where the tubes 502 and 504 are the same in terms of the material 
vibration-influencing variables discussed above, a flexural resonant 
vibrational wave in the compound tubing is achieved along the lines 
described above with reference to FIGS. 3-5. In this setting, however, the 
compound tube will normally be unable to achieve a conical spray; the 
spray pattern exhibiting by such a tube typically being in the form of a 
flat fan since the compound tube will oscillate in a plane transverse the 
juncture 506, along the line 0--0 in FIG. 15, by virtue of the disruptive 
interference provided by the juncture. Nonetheless, fine dispersions of 
fluid may be achieved in this flat fan mode. Further variations in the 
spray geometry of the compound tube 500 may be achieved by mismatching the 
physical or mechanical characteristics of the individual tubes 502 and 504 
constituting the composite, or fluid flow therethrough. For example, one 
tube may be formed from a relatively smaller size tubing or one may be 
formed with relatively thicker sidewalls than the other. Alterations in 
the flow of fluid issuing through each tube also permits variation of the 
flexural resonant mode in which the tubing vibrates. 
The compound tube 500 shown in FIGS. 14 and 15 is particularly well adapted 
for the introduction of disparate constituents to an air treatment 
apparatus where it is undesirable to mix those constituents initially and 
inject the mixture through a single tube. As fluid issues from the tubes 
it will admix as it is injected within the apparatus for desirable 
conditioning of any effluent residing therein. A particularly appropriate 
utility for such a compound tubing 500 is for the injection of physically 
disparate fluids, such as the injection of a conditioning gas through one 
tube and the injection of a conditioning liquid through the other. 
FIGS. 16 and 17 illustrate a variation on the compound tube 500 adapted for 
a similar utility. This compound tubing, designated generally as 600, 
includes a main fluid cohduit 602 and a secondary fluid conduit 604 formed 
integrally within the tube wall longitudinally thereof. The tubing 600 
will have an overall functionality quite similar to the compound tubing 
500; particularly insofar as the wall segment extending between the two 
channels 602 and 604 will provide a similar type of interference with the 
normal flexural vibration as is the case with the juncture 506 described 
above. Accordingly, the tube 600 will tend to oscillate along the line 
0--0 of FIG. 17, transverse the general axis lying along the tube between 
the fluid channels 602 and 604. Hence, a generally flat fan spray will be 
achieved as the tube oscillates in this manner. In the same way the 
compound tube 500 can be comprised of three or more tubes where that is 
necessary or desirable, the compound tube 600 can equally well be formed 
with three or more internal fluid channels to accommodate the need to 
supply three or more fluid agents through the nozzle. 
The tubing configuration shown in FIGS. 16 and 17 may be employed where it 
is difficult to secure, adhesively or otherwise, the separate tube 
members. Such may be the case where silicone tubing is the preferred 
material from which the nozzle is made. Otherwise, the mode of operation 
and range of utilities for the tubing structure 600 is generally 
coextensive with that for tubing 500. 
FIGS. 18 and 19 illustrate yet another variation. In this embodiment, a 
compound tube 700 is comprised of inner and outer tubes 702 and 704 
respectively. The tubes are sized so that the outer diameter of tube 702 
is less than the inner diameter of tube 704, whereby an annular chamber 
706 is formed intermediate two members, as best viewed in FIG. 19. The 
compound tubing 700 may be operated in a number of modes, with three 
particular configurations (upon which further refinements may be added) 
generally envisioned. The inner tubing 702 may be equal to, longer or 
shorter than, the tubing 704 whereby different characteristics are 
imparted to the composite. Initially, it will be appreciated that in 
situations where the inner tubing is shorter than outer tubing 704, fluids 
flowing through the separate tubings will admix near the tip of tubing 704 
in a very vigorous mixing mode as that tip oscillates. Thus, fluid 
dispersion and admixture is quite intimate in this configuration. Where 
the two tubes are approximately of equal length or where the inner tube 
702 is longer, admixture occurs within the spray pattern itself; the 
geometry of which will be governed in large measure by the distance to 
which tubing 702 projects beyond 704 (if at all) in addition to those 
parameters noted above. 
A further advantage of the configuration of the compound tubing 702 is its 
ability to effect a metering of conditioning agent. For example, the inner 
tubing 702 may be made from a relatively small sized tube having high 
flexibility (e.g., fine silicone tubing), one end of which is disposed 
within a reservoir containing a chemical agent to be dispensed. Fluid 
flowing through the annular channel 706, either gaseous or liquid, will 
create a low pressure zone at the tip of tube 702 terminating intermediate 
the length of the outer tubing. This will establish a type of venturi 
metering of fluid from the reservoir with which tube 702 communicates; the 
flow of which may be regulated by appropriately sizing tube 702 and/or, 
optionally, providing a type of flow regulator should that be needed 
(e.g., a needle valve). Thus, by suitable design within the foregoing 
parameters, a compound tube such as that represented in FIGS. 18 and 19 
may be employed for mixing disparate conditioning agents and/or metering 
thereof prior to or concurrent with the injection of same within the 
treatment zone of an air treatment apparatus. Furthermore, if three or 
more separate agents require mixing, additional tubes may be added to 
provide additional annular fluid passages for these additional agents. 
FIGS. 20 and 21 exemplify a convenient way to tune a flexible tube used as 
a discharge member on a nozzle employed in conjunction with the present 
invention. As noted above, with reference to FIGS. 6 and 7, a tuning 
sleeve can be employed to alter the effective length of the tubing to 
achieve a desired spray configuration while holding other variables 
constant. The assembly shown in FIGS. 20 and 21 achieves approximately the 
same result; but this approach has been found to permit a substantial 
physical reduction in the length of tubing necessary to achieve a desired 
flexural resonant vibration. 
FIG. 20 illustrates a length of flexible tubing 800 with which is 
associated a tuning-type member designated generally as 802. The tuning 
member, in the form of a clip, includes three legs 804, 806 and 808; the 
legs 804 and 808 having contact means 810 for engaging tube 800. The clip 
802 is dimensioned so that the legs themselves do not touch the tube wall, 
all contact being made along the contacts 810, which are shown to be 
diametrically opposite to establish a slight transverse compressive force 
on the tubing 800. As noted above, slight transverse constriction 
externally of a tube, and particularly a silicone rubber tube, permits the 
regulation of effective length and alteration of the spray geometry 
issuing therefrom. Thus, a considerably shorter length of tubing may be 
used to gain the same results. The amount of constriction is easily 
regulated by adjustment of the clip 802 to apply more or less pressure at 
the contacts 810. For example, the clip might be made simply out of a 
piece of relatively flexible but resilient metal stock whereby the same 
could be bent slightly. Alternately, other types of adjustable jaws, where 
bight pressure may be regulated, could equally well be employed. Further 
variation can be achieved by dimensioning the widths of the legs 804 and 
808 to be longer or shorter thereby increasing the line of contact from a 
short line or point to a relatively long line of constriction as compared 
with the diameter of tubing 800. Other variations may be achieved by 
increasing the number of contact elements 810; although it is usually 
important to space the contact members equiangularly about the 
circumference of tubing 800. Thus, should three contact members be 
employed, the spacing will be about 120.degree.; for four, 90.degree.. 
Usually, including more than four contact members will result in a clip 
which begins to function more like the sleeve 48 shown in FIGS. 6 and 7 
and, typically, that approach to tuning will become preferable. 
As is apparent from the foregoing description of the instant invention, air 
treatment apparatus which either rely on or can benefited by the 
introduction of a fluid agent may be provided with many added advantages 
when the fluid is injected through a nozzle terminating in a flexible tube 
which may be caused to resonate in a flexural vibrational mode. Thus, 
while the invention has now been described with reference to certain 
prefered embodiments within these contexts, those skilled in the art will 
appreciate that various substitutions, changes, modifications and 
omissions may be made without departing from the spirit thereof. 
Consequently, it is intended that the scope of the present invention be 
limited solely by that of the following claims. Along these lines, various 
conceptual departures from the specific suggested applications and 
utilities discussed above will be recognized by the skilled artisan to be 
achievable by using the apparatus and methods disclosed herein with but 
minor variations. 
For example, the apparatus disclosed herein will be recognized as devices 
customarily used for air treatment, that being the principal utility for 
cyclone separators, packed bed scrubbers, plenum scrubbers, and the like. 
However, utilitizing the same principles discussed in detail above for the 
conditioning of an air (or other gaseous) stream in apparatus with the 
injection system employed herein, one may treat liquid effluent streams by 
the injection of a suitable conditioning agent within a treatment zone 
wherein such liquid effluent resides. Thus, for example, water or other 
fluids laden with constituents to be removed (solid, liquid and/or gas) 
may be caused to reside in either a static or dynamic state within a 
treatment zone of an apparatus and suitable conditioning agent(s) injected 
therein. The liquid effluent may be circulated in a vortex in an analog to 
a cyclone, it may be allowed to flow in a stream in a fashion analogous to 
either a plenum or packed bed apparatus, or it may confined in a holding 
tank or the like for a static treatment. Conditioning agents, which may be 
gaseous or liquid or which may include a solid entrained in either or 
both, capable of effecting a suitable conditioning of the effluent, may be 
injected through a nozzle or an array of nozzles the same as those 
described above with reference to FIGS. 6, 7 and 14-21. A further benefit 
achieved in this environment is an active mixing of the liquid effluent 
with the added conditioning agent since movement of the flexible nozzle in 
its resonant vibrational mode will provide a high degree of agitation 
within the medium in the treatment zone; and this be true regardless of 
whether the conditioning agent is liquid or gaseous and whether it 
includes solid entrained in either or both. 
This leads to a further observation concerning the physical and chemical 
state of the conditioning agent introduced within the treatment zone 
regardless of its configuration and/or the matter to be treated therein. 
The only limitation on the conditioning agent is that it be sufficiently 
fluid to cause the flexible discharge tube to assume a vibrational mode. 
Thus, apart from the apparent applications where a pressurized liquid or a 
pressurized gas is the conditioning agent, or a combination of the two, 
large quantities of "fluidized solids" may be caused to issue from the 
discharge tube of the nozzle of the present invention. 
Those skilled in the art are well acquainted with the principles bottoming 
the construction and operation of so-called "fluidized beds" and the 
transport of solids in slurry form. As is known from fluid-bed technology, 
a solid material may be imparted with fluid-like attributes by flowing a 
fluid, typically a gas, through a bed of particulate solid material. Such 
a fluidized bed of solids will behave nearly the same as a liquid; for 
example, an object with a specific gravity higher than that of the bed 
will sink in it. In a similar vein, solids are oftentimes transported in 
the form of a slurry where solid entrained in a fluid, particularly 
liquid, may flow through a tube in the same way as a liquid stream. In 
much the same way, solids may be injected through the nozzles incorporated 
with the treatment devices of the instant invention. The only threshold 
limitation is that the solids be fluidized sufficiently to effect the 
vibration of the flexible discharge tube. The vibration of a given tube in 
this regard remains controlled by and a function of the same variables 
mentioned above governing vibration where, e.g., a liquid flows through 
the nozzle. 
In capsule sum, those skilled in the art will appreciate that the instant 
invention is broadly applicable to a host of conditioning treatments which 
may be performed within a number of suitable apparatus for treatment of a 
variety of effluents by means of wide range of conditioning agents. Thus, 
the following claims are intended to comprehend this wide utility.