Air scrubber apparatus

An air scrubber apparatus is provided for removing particles or fumes from an air stream. The apparatus first saturates the air stream with a liquid and then passes the air stream through a tortuous path defined by an arrangement of three internal baffles. The air stream impinges on two baffles which separate the liquid-particulate agglomeration from the air stream, after which it is directly channeled to a hopper while being shielded from the air stream. Another baffle is provided as a partition between the air flow and the hopper area to inhibit the reabsorption of particles by the air stream. The hopper is of V-shaped configuration which is effective in reducing the turbulence of the air flow around the base of the apparatus. In addition, the V-shaped hopper can accommodate more than one liquid filtering device. The subject apparatus may be provided with an adjustable baffle adjacent the air intake opening and adjustable vanes adjacent the air exhaust opening for varying the negative pressure created by the flow of air through the apparatus.

BACKGROUND OF THE INVENTION 
a. Field of the Invention 
The subject invention relates to a new and improved air scrubber apparatus 
for removing particles and fumes from an air stream. More particularly, an 
apparatus is provided which first saturates the air stream to form a 
liquid-particulate agglomeration and then draws the air stream through a 
tortuous path defined by an arrangement of three baffles which function to 
separate the agglomeration from the air stream. The subject invention also 
includes a new and improved hopper which reduces turbulence of the air 
stream and is capable of accommodating a plurality of filtering devices 
for separating the particulates from the liquid. 
b. Description of the Prior Art 
As an example of the use of an air scrubber apparatus, during the drying of 
textiles the tumbling action caused by the rotating drums of the dryers 
results in small lint particles being shorn free of the materials, which 
are then carried away in the hot air exhaust. In large industrial 
applications, it has been found that a separate apparatus must be provided 
to remove the lint particles from the air stream prior to venting the air 
stream to the atmosphere. Original attempts to "scrub" the air involved 
simply passing the lint-laden air stream through filters to collect the 
lint particles. This method was not entirely satisfactory in that the 
collected lint occupied large amounts of space and, in addition, created a 
fire hazard. Further, as the filter became increasingly clogged with lint 
particles the drawing efficiency or "negative pressure" created by the 
scrubbing or collector apparatus would decrease. Maintaining a constant 
negative pressure relative to the dryers is necessary because if the 
drawing pressure of the lint collector apparatus is too small, the air 
stream will not be properly pulled through the lint collector and the lint 
will not be removed. On the other hand, if the negative pressure is too 
large, the hot air is drawn out of the dryers before it has a chance to 
dry the textiles, thus decreasing the efficiency of the dryers and 
increasing heating and operating costs. To alleviate these drawbacks, one 
form of prior art air scrubber or lint collector separates the air stream 
as it enters the collector apparatus, such that the lint particles are 
trapped in the liquid and thus form an agglomeration. The collector 
apparatus then separates the liquid-lint agglomeration from the air 
stream, so that the agglomeration can be filtered. This system was 
advantageous in that the moistened lint occupies a much smaller volume, 
and since it was moist, it created no fire hazard. In addition, since the 
air flow is not required to pass through filters, a constant negative 
pressure relative to the dryers could be substantially maintained. 
Prior art liquid air scrubbers separate the liquid-lint agglomeration from 
the air stream by causing the air stream to impinge on a central baffle 
within the housing of the collector apparatus. The impingement of the air 
flow on the baffle results in a portion of the liquid-lint agglomeration 
being trapped by the baffle where it subsequently runs down into a 
collecting pan or hopper. It was found, however, that the baffle 
arrangement in the prior art apparatus could not effectively remove enough 
of the liquid-lint agglomeration as was necessary to provide adequate 
scrubbing of the air stream. 
Another shortcoming of the prior art apparatus is that the water which 
cascades down the baffle towards the hopper could be reabsorbed by the air 
flow before it was filtered. More particularly, the hopper found in prior 
art devices, which defines the bottom of the housing, is generally of a 
truncated inverted pyramidal configuration, thus allowing the liquid-lint 
agglomeration to flow downwardly towards a central opening, where a 
filtering means is located. Thus, the inverted truncated pyramidal 
configuration provides only one collection point for the liquid-lint 
agglomeration. Hence, the prior art device could accommodate only one 
filtering means which must be frequently attended to. In addition, as the 
air stream passes over the inverted truncated pyramidal configuration, a 
great deal of turbulence results, which had the effect of stirring up the 
liquid-lint agglomeration collected in the hopper, thus causing some of 
the lint particles to be reabsorbed into the air stream and thus 
decreasing the efficiency of the apparatus. 
Another shortcoming of the prior art apparatus relates to the physical 
distance between the lint removing device and the dryers. This distance 
directly affects the amount of drawing force or negative pressure which 
must be created by the apparatus for efficient operation. Since the 
distance from the dryers to the prior art device varies with different 
customers, the required negative pressure was found to be difficult to 
achieve since only minor variations in the negative pressure could be 
obtained by means of altering the fan speed of the prior art device. 
Accordingly, considering the shortcomings of the prior art devices, it is 
among the objects of the subject invention to provide an apparatus for 
removing particulates from an air stream which has a baffle arrangement 
which effectively removes a liquid-particulate agglomeration from an air 
stream. 
It is a further object of the subject invention to provide an apparatus for 
removing particulates from an air stream which has a new and improved 
hopper design that will reduce the turbulence of the air flow. 
It is another object of the subject invention to provide an apparatus for 
removing particulates from an air stream which has a hopper design which 
can accommodate more than one filtering means for the liquid-particulate 
agglomeration. 
It is still a further object of the subject invention to provide an 
apparatus for removing particulate from an air stream which includes a 
means for adjusting the negative pressure created by the apparatus. 
Another object of the subject invention is to provide an apparatus for 
removing particulates from an air stream which isolates the trapped 
liquid-particulate agglomeration from the air stream as it runs down 
towards the hopper to prevent reabsorption of the particles. 
It is still a further object of the subject invention to provide an 
apparatus for removing particulates from an air stream which inhibits the 
reabsorption of particles by the air stream as it flows past by the 
liquid-particulate agglomeration collected in the hopper. 
SUMMARY OF THE INVENTION 
In accordance with these and other objects, the subject invention provides 
an air scrubber apparatus for removing particulates from an air stream 
with a new and improved baffle arrangement and hopper configuration. More 
particularly, the air scrubber apparatus of the subject invention includes 
a housing with an air intake opening on one side thereof and an air 
exhaust opening disposed on the other side of the housing. The housing 
includes a hopper which defines the bottom of the housing and is of 
V-shaped configuration. The V-shaped configuration of the hopper is 
effective in reducing the turbulence of the air flow as it passes by the 
hopper, thereby minimizing the reabsorption of particulates from the 
liquid collected in the hopper. In addition, the V-shaped configuration of 
the hopper can accommodate more than one filtering means, which reduces 
the need for frequent maintenance of the apparatus and cleaning of the 
filtering means. 
The subject apparatus includes three internal baffles arranged so as to 
guide the air flow in a tortuous path through the housing where the 
liquid-particulate agglomeration is removed. More particularly, a first 
baffle is provided adjacent to the air intake opening and at an angle 
thereto. Directly above the first baffle, nozzles are situated which spray 
a liquid onto the incoming air stream to saturate the air stream in order 
to create the liquid-particulate agglomeration. A portion of the saturated 
air stream impinges on the first baffle such that a portion of the 
liquid-particulate agglomeration becomes trapped on the first baffle and 
cascades downwardly toward the hopper. A passageway is provided at the 
bottom of the first baffle to directly channel the liquid-particulate 
agglomeration to the hopper, thus isolating the agglomeration from the air 
flow and inhibiting the reabsorption of the particulates. 
A second baffle is provided adjacent the first baffle and is disposed 
central to the housing and consists of a partition portion and a trough 
portion. The partition portion extends vertically downwardly to a point 
intermediate the height of the housing. The trough portion is connected to 
the bottom edge of the partition portion and is disposed perpendicular 
thereto. The second baffle performs the dual function of changing the 
direction of the air flow, while supplying a second impingement surface. 
When the air flow strikes the second baffle, it experiences an essentially 
180.degree. change of direction. Since the air flow can change its 
direction faster than the liquid particulate agglomeration, another 
portion of the agglomeration is trapped by the second baffle and removed 
from the air stream. The trough portion collects the agglomeration as it 
runs down the partition portion. The trough portion extends across the 
entire width of the housing and has openings along its edges which are in 
communication with a pair of conduits which empty directly into the 
hopper. Thus, the liquid-particulate agglomeration separated by the second 
baffle is routed directly to the hopper and isolated from further contact 
with the air stream which inhibits reabsorption of particulates. A portion 
of the first baffle overhangs a portion of the trough so that the first 
and second baffles cooperate to cause the air stream to flow in a tortuous 
S-shaped path providing the maximum impingement of the air stream to 
efficiently separate the liquid-particulate agglomeration therefrom. The 
air stream is then further twisted around a tortuous path towards the air 
exhaust opening at the rear upper portion of the housing. In this final 
stage, the air stream is drawn upwardly through a large volume which 
causes the air to expand, and thus decrease in velocity which, in turn, 
permits any remaining moist particles to fall under the influence of 
gravity into the hopper. Hence, the arrangement in the subject invention 
effectively provides for a three stage removal of the liquid-particulate 
agglomeration from the air stream. 
In addition, means are provided for adjusting the negative pressure created 
by the subject air scrubber apparatus so that the latter may be readily 
adapted to each individual installation. More particularly, the first 
baffle is inclined at an angle to the horizontal and cooperates with the 
housing of the apparatus to effectively define a venturi through which the 
air stream passes. The first baffle is adjustable in length such that a 
large portion of the air intake opening can be variably restricted for 
reducing the air flow and the negative pressure created by the apparatus. 
In addition, adjustable vane members are provided adjacent the air exhaust 
opening for adjusting the negative pressure created by the apparatus. 
The subject apparatus is also provided with a third baffle which is 
disposed directly above the apex of the V-shaped hopper. The third baffle 
acts as a fairing or partition between the hopper and the air flow to 
inhibit the reabsorption of the liquid-particulate agglomeration back into 
the air flow. The third baffle is preferably disposed such that the 
distance between the hopper and the front edge of said third baffle 
adjacent the air intake opening is smaller than the distance between the 
hopper and the opposed edge of the third baffle, thereby inhibiting the 
flow of air from passing under the third baffle and into contact with the 
liquid-particulate agglomeration. The spacing along the front edge of the 
third baffle is sufficient to allow the liquid-lint agglomeration to run 
from the conduit of the first baffle into the apex of the hopper.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Although the subject invention will be described with reference to an 
application for removing or scrubbing lint particles from an air stream, 
it should be understood that the invention may also be employed in other 
applications for removing various types of particulate matter or fumes 
from an air stream. 
Referring to FIG. 1, the lint collecting apparatus of the subject invention 
is designated by the numeral 10 and includes a generally rectangular 
housing 12 which includes an air intake opening 14 and an air exhaust 
opening 16. The bottom of housing 12 is defined by a generally V-shaped 
hopper 18 and rests on a stand 20 with a filter tank 22 located below and 
communicating with hopper 18. An exhaust fan assembly 24, including fan 
24a, tapered chamber 24b, and sealing strips 24c, is provided on top of 
housing 12 and in communication with the air exhaust opening 16. Air 
exhaust opening 16 and exhaust fan assembly 24 may be disposed along the 
rear wall of housing 12 when necessary to meet the requirements of a 
particular installation. 
A first baffle 26 is provided adjacent the air intake opening 14 and 
extends the entire width of housing 12. As more particularly illustrated 
in FIG. 4, first baffle 26 is disposed from the horizontal at an angle 
ranging from 15.degree.-45.degree.. The first baffle 26 consists of a 
fixed section 28 and a movable or adjustable section 30 such that the 
length of the first baffle 26 may be adjusted by extending or retracting 
the movable section 30. The latter is fixed to the section 28 by means of 
wing nuts 34 or any other suitable fastening means. Fixed section 28 is 
reinforced by stiffeners 32. An inner wall member 36 is connected to the 
bottom end of fixed section 28 of the first baffle 26, and is disposed 
parallel to and cooperates with the front wall of housing 12 to form a 
passageway 38, as shown in FIG. 2. Passageway 38 extends from the bottom 
of first baffle 26 and terminates at the hopper 18. 
A hot air stream, indicated by arrow A, which is laden with lint particles 
(not shown) initially enters the housing 12 through air intake opening 14. 
The air stream is then saturated by a liquid L which is sprayed from 
nozzles 40. Preferably, nozzles 40 are arranged in staggered rows of four 
or five nozzles, and each nozzle provides a spray pattern which will fully 
saturate the air flow A. The liquid L combines with the lint particles of 
the air stream to form a liquid-particulate agglomeration. In operation, 
as the air stream enters the housing it is saturated by the liquid spray 
and a portion of the saturated air stream impinges on first baffle 26 
which functions to separate the liquid-particulate agglomeration from the 
air stream. As indicated by arrow B, the liquid-particulate agglomeration 
cascades down the first baffle 26 and into passageway 38 where it is 
channeled to hopper 18. By this arrangement, the inner wall member 36 
functions to isolate the liquid-particulate agglomeration from the air 
stream within the housing and thus prevents reabsorption of the 
particulates into the air stream, as more fully described hereinafter. 
Adjustment of the length of the first baffle 26 provides a means by which 
the amount of negative pressure produced by apparatus 10 can be regulated. 
As the length of the first baffle 26 is increased, the air intake opening 
14 becomes obstructed thereby reducing the negative pressure generated by 
the apparatus 10. As noted above, a fixed negative pressure created by the 
apparatus must be maintained at an optimum level in order to produce 
maximum efficiency, thereby reducing operating cost of the apparatus. 
The free end of adjustable section 30 of the first baffle 26 is provided 
with a hook-shaped lip or projection 42, as illustrated more particularly 
in FIG. 4. It has been found that since the air stream enters the housing 
12 at a high velocity, it tends to cause any liquid which has accumulated 
at the end of the first baffle 26 to be carried off into the air flow. The 
hook-shaped projection 42 is provided to prevent the air stream from 
reabsorbing or carrying the liquid beyond the end of the first baffle 26. 
Thus, the liquid-particulate agglomeration trapped by the lip 40 on the 
section 28 runs down the baffle 26 and into passageway 38. 
A second baffle 44 extends the entire width of housing 12, and consists of 
upper 46 and lower 48 planar members, and trough 50. Upper planar member 
46 is fixedly connected to the top of housing 12 and extends downwardly 
and rearwardly therefrom, while lower planar member 48 is connected to the 
bottom of upper planar member 46 and extends downwardly and forwardly with 
respect to housing 12. Trough 50 is connected to the bottom of the lower 
planar member 48 and is disposed generally horizontal. Preferably, lower 
planar member 48 is removably connected to trough 50 and upper planar 
member 46 by slide mountings so that lower planar member 48 may be easily 
removed to facilitate maintenance of the apparatus including first baffle 
26 and nozzles 40. Trough 50 is provided with openings 52 disposed on 
opposed edges thereof, as most clearly illustrated in FIG. 1. Openings 52 
communicate with conduits 54 which are spot welded to the opposed side 
ends of housing 12 and extend downwardly to the hopper 18. 
In operation, after the air stream passes first baffle 26, second baffle 44 
causes the air stream to change its direction approximately 180.degree. so 
it follows a tortuous path through housing 12, as indicated by arrow C. 
More particularly, the baffles are arranged so that first baffle 26 
overhangs second baffle 48 such that a tortuous S-shaped path is formed 
which the air stream must follow. When the high speed air stream impinges 
on second baffle 44, it is able to change direction faster than the 
liquid-particulate agglomeration such that the liquid-particulate 
agglomeration impinges on and is trapped by second baffle 44 and is caused 
to run down panel members 46 and 48 into the trough portion 50. The 
liquid-particulate agglomeration is then channeled through openings 52 and 
the side wall conduits 54 to hopper 18. It is noted that the vertical 
flange forming a portion of the trough 50 effectively functions as a wall 
or additional impinging baffle for the airflow as it reverses its 
direction, thereby aiding in removal of the liquid-particulate 
agglomeration. 
The hopper 18 has a V-shaped configuration, as clearly illustrated in FIG. 
1. As indicated by arrow D, after the air stream passes second baffle 44 
it is redirected by inner wall member 36 towards the rear of housing 12. 
The V-shaped configuration of hopper 18 aids in reducing air turbulence 
created by the hopper and enables an essentially laminar flow path for the 
air flow. By reducing the amount of turbulence in and around the hopper 
area, the reabsorption of particles from the liquid-particulate 
agglomeration collected in the hopper is inhibited. To further minimize 
the potential for the liquid-particulate agglomeration to be reabsorbed by 
the air stream, a third baffle 56 is provided and extends across the width 
of hopper 18. Third baffle 56 functions as a divider separating the air 
stream from the liquid-particulate agglomeration collected in the hopper. 
Further, the spacing between hopper 18 and the leading edge 58 of the 
third baffle 56 is preferably smaller than the spacing between the hopper 
18 and the trailing edge 60 of said third baffle 56. This configuration is 
effective in restricting the air stream from passing underneath the third 
baffle 56, thereby inhibiting the reabsorption of particles from the 
liquid-particulate agglomeration. 
After the air stream passes through the passageway defined by the bottom of 
trough 50 and third baffle 56, it is drawn into the rear open volume 66 of 
housing 12, as indicated by arrows E. As the air stream enters open volume 
66, it expands and thus its velocity decreases, such that remaining 
particles descend by gravity into hopper 18. The air stream is finally 
drawn out of apparatus 10 through air exhaust opening 16 by fan member 24. 
To further facilitate the adjustment of the negative pressure created by 
air scrubber apparatus 10, adjustable vanes 68, 68 may be provided, with 
each vane being pivotally mounted adjacent the air exhaust opening 16. In 
operation, each adjustable vane 68, 68 may be pivoted about a central axis 
to effectively vary the size of the air exhaust opening 16 leading to 
tapered housing 24b. By adjusting the size of the air exhaust opening 16, 
the amount of negative pressure created by the air scrubber apparatus 10 
may be further regulated, thereby facilitating the creation of optimum 
pressure conditions to create maximum efficiency of the apparatus. 
In order to maximize the total amount of particulates removed from the air 
stream by the time it exits the apparatus 10, it is necessary to severaly 
limit the reabsorption of the liquid-particulate agglomeration by the air 
stream after it has been initially separated therefrom. To reduce the 
likelihood of reabsorption, the apparatus 10 isolates the 
liquid-particulate agglomeration which has been separated from the air 
stream from further contact with the air stream. More particularly, 
passageway 38 which is defined by the cooperation between inner wall 
member 36 and the front wall of housing 12 functions to isolate the 
liquid-particulate agglomeration separated by first baffle 26 from the air 
stream as it cascades down towards the hopper 18. Thus, the air stream, as 
indicated by arrow D, which passes by the outer surface of inner wall 
member 36 does not come into contact with the liquid-particulate 
agglomeration and therefore reabsorption is inhibited. In addition, 
conduits 54 are provided along the opposed side edges of housing 12 to 
channel the liquid-particulate agglomeration separated by second baffle 44 
directly to hopper 18 so that the air stream passing under trough section 
50 will not reabsorb the particles therefrom. By preventing the 
reabsorption of particles by the air stream, the efficiency of the 
apparatus 10 is greatly increased. 
In operation, the liquid-particulate agglomeration is collected in hopper 
18 from passageway 38, conduits 54, and from rear open area 66. It is 
noted that the spacing between hopper 18 and the leading edge of third 
baffle 58 must be sufficient to allow the liquid-particulate agglomeration 
from passageway 38 to run down into the apex of the V-shaped hopper (see 
arrow F). An opening 70 is provided at the apex of the V-shaped hopper as 
an exit point for the liquid-particulate agglomeration such that lint or 
particles may be filtered from the liquid-particulate agglomeration. The 
configuration of hopper 18, in addition to reducing the turbulence of the 
air stream, functions to accommodate the addition of more than one 
filtering device. As illustrated by phantom lines 71 in FIG. 3, due to the 
V-shaped configuration of the hopper 18 a plurality of filtering devices 
can be provided along the bottom linear apex of hopper 18. This 
arrangement is advantageous due to the fact that since filter bags need 
periodic servicing, an increase in the number of filtering devices will 
reduce the frequency of maintenance checks. 
The preferred filtering device of the subject invention consists of a three 
filter system including a primary filter bag 72, a secondary filter bag 74 
and a filter screen 76, all housed within filter tank 22. The 
liquid-particulate agglomeration is first passed through a fine mesh 
primary filter bag 72 where a high percentage of the lint particles is 
filterred from the agglomeration. A large secondary filter bag 74, having 
a mesh at least as fine as primary filter bag 72, totally surrounds the 
primary filter bag to additionally separate lint particles from the 
agglomeration. The secondary filter bag 74 is large enough so that the 
liquid flow will not be impeded as the bag fills with lint particles. In 
addition, a screen 76 is provided as a final means for trapping any lint 
particles remaining in the liquid. Preferably after the liquid has been 
filtered, it is recirculated through vent 78 back to nozzles 42 to 
saturate the subsequent air stream entering the air scrubber apparatus 10. 
Accordingly, there is provided a new and improved apparatus for removing 
particulates from an air stream. More particularly, the subject apparatus 
provides a new and improved three baffle arrangement which can effectively 
remove large portions of particulates from an air stream. As the air 
stream enters the housing 12 through the air intake opening 14, it is 
saturated by a liquid L to form a liquid-particulate agglomeration. The 
air stream is then caused to impinge on an adjustable first baffle 26 
which separates a portion of the liquid-particulate agglomeration from the 
air stream. The liquid-particulate agglomeration is then channeled 
directly to the hopper section 18 via a passageway 38, thus shielding the 
agglomeration from the downstream air stream and inhibiting reabsorption 
of the particles. The air stream is drawn through a tortuous S-shaped path 
defined by the cooperation of the first and second baffles 26, 44. The air 
stream impinges on the second baffle 44 and another portion of the 
liquid-particulate agglomeration is separated therefrom. The agglomeration 
is directly channeled via a pair of conduits 54 from the collecting trough 
50 of the second baffle 44 to the hopper 18 to thus inhibit the 
reabsorption of the particles. In addition, a third baffle 56 is provided 
as a fairing or partition between the air stream and the hopper section 18 
to further inhibit the reabsorption of particles by the air stream. The 
air stream is then drawn around into a rear open area 66 where it expands 
and slows, thereby allowing any of the remaining liquid-particulate 
agglomeration to fall back into the hopper 18. The new and improved 
V-shaped hopper is effective in reducing the turbulence of the air stream 
around the base of the apparatus 10 which, in turn, reduces the 
reabsorption of particulate from the liquid collected in the hopper 18. In 
addition, the new and improved V-shaped hopper 18 can accommodate more 
than one filtering means which thereby reduces the need for frequent 
maintenance. The apparatus of the subject invention further provides means 
to adjust the negative pressure created by the apparatus. The means 
includes the adjustable first baffle 26 which can be extended to reduce 
the size of the air intake opening and thus restrict the amount of air 
flow passing therethrough. Further, adjustable vanes 68, 68 are provided 
adjacent the air exhaust opening 16 for obstructing that opening and 
reducing the air flow therethrough. A fan means 24 is provided adjacent 
the air exhaust opening 16 to draw the air stream through the housing 12 
of the apparatus 10. 
Although the subject apparatus has been described by reference to a 
preferred embodiment, it will be apparent that many other modifications 
could be derived by those skilled in the art that would fall within the 
spirit and scope of the present invention as defined by the appended 
claims.