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| United States Patent |
6,126,722 |
| Mitchell , et al. |
October 3, 2000 |
Electrostatic reduction system for reducing airborne dust and
microorganisms
Abstract
A dust reduction system for reducing airborne contaminants such as, for
example, dust, smoke, microorganisms, etc., includes at least one ion generator
made up of at least one ionizer bar and a ground plane which is parallel and
proximate to at least one bar. The system can also include a dust collection
device such as a tray containing an aqueous composition optionally containing a
degreaser, and/or a metal sheet with a water rinse system, and/or the surfaces
of a room-sized enclosed space. The system can be applied to any enclosed space
where it is desired to obtain high efficiency reduction of airborne dust and
microorganisms. The system is especially useful in poultry production and
processing areas such as hatching cabinets, throwing rooms, and controlled
environment poultry rearing rooms.
| Inventors: |
Mitchell; Bailey W. (Watkinsville, GA);
Stone; Henry D. (Winterville, GA) |
| Assignee: |
The United States of America as represented
by the Secretary of (Washington, DC) |
| Appl. No.: |
122850 |
| Filed: |
July 28, 1998 |
| Current U.S. Class: |
95/57; 95/64; 95/71; 96/53;
96/97; 361/226; 361/231 |
| Intern'l Class: |
B03C 003/019 |
| Field of Search: |
96/97,96,52,53 95/57,64,71
361/226,231-233,235 |
References Cited [Referenced
By]
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Other References
Mitchell et al., Avian Diseases, vol. 38, pp. 725-732,
1994. |
Primary Examiner: Chiesa; Richard L.
Attorney, Agent or Firm: Silverstein; M. Howard, Fado; John D.,
Poulos; Gail E.
Claims
We claim:
1. A space charge system for reducing airborne
contaminants comprising
(a) at least one negative air ion generator
wherein said generator includes at least one ionizing electrode,
(b) a
ground plane perpendicular and proximate to said at least one electrode wherein
said at least one electrode is facing away from said ground plane, and at a
distance apart to create an electrostatic field which reduces airborne
particulates without creating an arc, and
(c) a source of power to
effect said ionization from said electrode;
wherein said system
generates electrostatic charge throughout an enclosed space outside of said
system.
2. The system of claim 1 further comprising about 3 to 12
ionizer bars containing a plurality of electrodes.
3. The system of
claim 1 wherein said system further comprises at least one dust collection
device.
4. The system of claim 1 wherein said at least one electrode is
an ionizing needle electrode.
5. The system of claim 3 wherein said dust
collection device is at least one tray containing an aqueous composition.
6. The system of claim 5 wherein said aqueous composition includes a
degreaser.
7. The system of claim 3 wherein said dust collection device
includes a metal plate and a means for applying water to said plate.
8.
The system of claim 7 wherein said means for applying water to said plate is
spray nozzles.
9. The system of claim 7 wherein said means for applying
water to said plate is a pipe containing holes for emitting water.
10.
The system of claim 3 wherein said dust collection device is said ground plane
and surfaces of a room-sized enclosed space.
11. The system of claim 3
wherein said dust collection device is at least one tray containing an aqueous
composition wherein said at least one tray is located above said generator and
ground plane.
12. The system of claim 11 wherein said dust collection
device further comprises a second tray located at the bottom of the enclosed
space below said generator and ground plane.
13. The system of claim 3
wherein said dust collection device comprises at least one grounded metal plate
attached to at least one wall of said enclosed space.
14. The system of
claim 13 further comprising spray nozzles mounted as selected from the group
consisting of beside the plate, above the plate, and both beside and above the
plate.
15. The system of claim 1 wherein said generator further includes
a supporting frame.
16. A space charge system for reducing airborne
contaminants comprising
(a) at least one negative air ion generator
wherein said generator includes at least one ionizing electrode,
(b) a
ground plane perpendicular and proximate to said at least one electrode wherein
said at least one electrode is facing away from said ground plane, and at a
distance apart to create an electrostatic field which reduces airborne
particulates in an enclosed space outside of said system without creating an
arc, and
(c) a dust collection device wherein said device is selected
from the group consisting of said ground plane and surfaces of a room-sized
enclosed space, a tray containing an aqueous composition, and a metal sheet with
spray nozzles.
17. A method for reducing airborne particulates
comprising
(a) installing a space charge system in an enclosed space
wherein said system comprises at least one negative air ion generator wherein
said generator includes at least one ionizing electrode and a ground plane
perpendicular and proximate to said at least one electrode wherein said at least
one electrode is facing away from said ground plane, and at a distance apart to
create an electrostatic field which reduces airborne particulates without
creating an arc,
(b) applying a high negative voltage to the generator
to generate an electrostatic field,
(c) dispersing negative
electrostatic charge throughout said space outside of said system, and
(d) collecting airborne particulates in or on a dust collection device.
18. The method of claim 17 wherein said dust collection device is at
least one tray containing an aqueous composition wherein said at least one tray
is located above said generator and ground plane.
19. The method of
claim 18 wherein said dust collection device further comprises a second tray
located at the bottom of the enclosed space below said generator and ground
plane.
20. The method of claim 17 wherein said dust collection device
comprises at least on grounded metal plate attached to at least one wall of said
enclosed space.
21. The method of claim 20 further comprising spray
nozzles mounted as selected from the group consisting of beside the plate, above
the plate, and both beside and above the plate.
22. The method of claim
17 wherein the voltage is in the range of about -15,000 volts dc to about
-30,000 volts dc.
23. The method of claim 17 wherein said dust
collection device is selected from the group consisting of said ground plane and
surfaces of a room-sized enclosed space, a tray containing an aqueous
composition, and a metal plate with spray nozzles.
24. The method of
claim 17 wherein said generator is made up of about 3-12 ionizer bars each
containing a plurality of ionizing needle electrodes.
25. A space charge
system for reducing airborne contaminants comprising,
(a) at least one
negative air ion generator wherein said generator includes at least one ionizing
electrode,
(b) a ground plane perpendicular and proximate to said at
least one electrode wherein said at least one electrode is facing away from said
ground plane, and at a distance apart to create an electrostatic field which
reduces airborne particulates in an enclosed space outside of said system
without creating an arc, and
(c) a dust collection device wherein said
device comprises a first tray containing an aqueous composition located above
said generator and ground plane and a second tray containing an aqueous
composition located at the bottom of the enclosed space below said generator and
ground plane, and
(d) a source of power to effect said ionization from
said electrode.
26. A space charge system for reducing airborne
contaminants comprising,
(a) at least one negative air ion generator
wherein said generator includes at least one ionizing electrode,
(b) a
ground plane perpendicular and proximate to said at least one electrode wherein
said at least one electrode is facing away from said ground plane, and at a
distance apart to create an electrostatic field which reduces airborne
particulates in an enclosed space outside of said system without creating an
arc, and
(c) a dust collection device wherein said device comprises at
least one grounded metal plate attached to at least one wall of said enclosed
space and spray nozzles mounted as selected from the group consisting of beside
the plate, above the plate, and both beside and above the plate, and
(d)
a source of power to effect said ionization from said electrode.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an electrostatic dust reduction system and a
method for reducing dust, air contaminates, and airborne microorganisms in
enclosed spaces, such as for example, poultry hatching cabinets, throwing rooms
and controlled environment poultry rearing rooms, for example. The present
invention reduces dust, microbial contamination and infection, especially of
newly hatched chicks and poultry, including contamination and infection with
human enteropathogenic organisms.
2. Description of the Related Art
The consumption of improperly prepared poultry products has resulted in
numerous cases of human intestinal diseases. It has long been recognized that
Salmonella spp. are causative agents of such diseases, and more recently
Camplylobacter spp. As many as two million cases of salmonellosis occur annually
in the United States (Stavrix et al., Journal of Food Protection, Volume 56, No.
2, 173-180, February, 1993); twice as many cases of campylobacteriosis are
thought to occur (Krienberg et al., Food Technology, pages 77,80,81, and 98,
July 1987). Both microorganisms may colonize poultry gastrointestinal tracts
without any deleterious effects on the birds, and although some colonized birds
can be detected, asymptomatic carriers can freely spread the microorganisms
during production and processing, resulting in further contamination of both
live birds and carcasses. Poultry serve as the primary reservoir for Salmonella
and Campylobacter in the food supply (Jones et al., Journal of Food Protection,
Volume 54, No. 4, 259-262, April 1991; Jones et al., Journal of Food Protection,
Volume 54, No. 7, 502-507, July 1991). The intestinal contents of chickens may
harbor up to 10.sup.7 Campylobacter and/or Salmonella per gram, and cross
contamination during processing is frequent (Oosterom et al., Journal of Food
Protection, Volume 46, No. 4, 339-344, April 1983). Studies have demonstrated
that fecal material constitutes the major source from which edible parts of
chickens are contaminated in processing plants. Therefore, to significantly
reduce the level of contamination on processed poultry, pathogen-free birds must
be delivered to the processing plant (Bailey, Poultry Science, Volume 72,
1169-1173, 1993).
Better control measures are needed to minimize the
spread of these and other human enteropathogenic bacteria; and the most
promising approach to achieve this end has been to decrease the incidence and
level of colonization by these microorganisms in poultry gastrointestinal
tracts. Hatching cabinets are known to be one of the primary sources for human
enteropathogenic bacteria contamination of poultry. A considerable amount of
dust is generated during the hatching process from the time of piping on day 20
through final hatching on day 21 of incubation. The dust is caused by the
breaking up of egg shells and feather particles which are entrained into the air
from the new chicks as they move around. Bailey et al (Poultry Science, Volume
71 (1):6; and Poultry Science, Volume 73(7), 1153-1157, 1994) demonstrated that
a single salmonella contaminated egg could contaminate most of the eggs and
newly hatched chicks in a hatching cabinet. This result suggests that extensive
airborne transmission of the bacteria is possible since the typical hatching
cabinet has several trays of fertile eggs on several different levels and on
several different carts. Eggshell fragments, belting materials, and paper pads
used in commercial hatcheries have also been shown to be sources of salmonella
contamination (Cox et al, Poultry Sciences, Volume 69, 1606-1609, 1990).
Various intervention approaches have been taken in attempts to reduce
airborne transmission of disease. Bailey et al (Poultry Science, Volume 75(2),
191-196, 1995) have demonstrated that chemical treatment of hatching cabinet air
between day 18 and hatch can significantly reduce disease transmission caused by
eggs which are internally contaminated with Salmonella. Treatments included
UV-light, ozone, and fogging with hydrogen peroxide. The hydrogen peroxide
treatment was the most effective in reducing salmonella on the shells, in the
air, and in the chicks. Hopkins and Drury (Avian Diseases, Volume 15, 596-603,
1971) have demonstrated the ability of airborne diseases such as Newcastle
disease virus (NDV) to be transmitted from groups of donor chickens to groups of
susceptible chickens and the ability of high efficiency filters to interrupt
this transmission. Madelin and Wathes (British Poultry Sciences, Volume 30,
23-37, 1989) found that a raised floor for broilers reduced respirable dust by a
factor of 2 compared to dust in a room with broilers on deep liter. The airborne
bacterial cfu counts were reduced by a factor of 3000 by the raised floors.
Carpenter et al (British Poultry Sciences, Volume 27, 471-480, 1986) found that
a recirculating high efficiency filter in a broiler house room reduced dust
levels to about half that of an untreated room, and it reduced the concentration
of airborne bacteria more than 100 fold.
Hugh-Jones et al (J. Hyg.,
Camb., Volume 71, 325-339, 1973) reported 63% of the NDV and 83-94% of total
bacteria in poultry houses was found on particles >6 microns. Thirty-six
percent of the NDV was on 3-6 micron particles. Estola et al (Journal of
Hygiene, Volume 83, 59-67, 1979) reported complete protection from airborne
transmission of Newcastle disease virus by negative air ionizers but later
studies (Mitchell and King, Avian Diseases, Volume 38, 725-732, 1994) have not
been able to confirm their results. The studies of Mitchell and King (1994,
supra), in controlled environment transmission cabinets, resulted in reductions
in airborne transmission of NDV of up to 28% using negative air ionizers, but
they hypothesized that higher reductions were possible with more efficient ion
generators and ion distribution systems. Since previous reports indicate that
most airborne bacteria and viruses are attached to larger particles, it is
useful to look at dust reduction studies which did not involve microorganisms.
Hoenig et al (Foundrymens Soc. Transactions, Volume 84, 55-64, 1976)
used a charged spray to reduce silica sand dust from 20 mg/m.sup.3 to 2
mg/m.sup.3 with positively charged water fog. Mitchell (ASAE Paper 954592,
Chicago, Ill., 1995) reported improvements in decay rates of up to 42 fold for
total inhalable particles using a negative air ionizer. Ionizers have been used
to achieve dust reductions of up to 67% (Bundy and Veenhuizen, Proc. CIGR,
Latest Dev. in Livestock Housing, Urbana, Ill., June 1987; Czarick and Van
Wicken, ASAE Paper 85-4510, Winter MTG ASAE, Chicago, Ill., 1985) in animal
housing. Repace et al. (Clinical Ecology, Volume 11 (2), 90-94, Winter
1983-1984) showed ionizers could accelerate the precipitation of smoke particles
in an unventilated room by up to a factor of 18 or up to an equivalent
ventilation rate of 6 air changes per hour.
Saurenman et al. (U.S. Pat.
No. 3,696,791-Oct. 10, 1972) disclose the use of air ionization for reducing
air-borne particulates and ammonia gas and odors in feeding enclosures of
animals, especially poultry. Ions are dispersed into the feeding areas. The
device includes a means to disperse ions suspended overhead, a static voltage
sensor, a control device, a voltage generator, a blower, and a positively
charged conductive grid.
Saurenman (U.S. Pat. Nos. 4,388,667['667]-Jun.
14, 1983; 4,390,923['923]-Jun. 28, 1983; and 4, 493,289['289]-Jan. 15, 1985)
discloses devices for reducing air-borne particulates and ammonia gas and odors
in feeding enclosures of animals, especially poultry, using air ionization. The
'289 patent discloses a device with flexible cables containing an elongated and
sidewardly penetratable metallic core to which voltage is applicable. The cable
includes a protective sleeve of insulating material and needles having shanks
penetrating through the sleeve and extending sidewardly adjacent the core to
make electrical contact with the core so as to receive application of voltage in
order to dispense ions into the atmosphere from tips exposed outwardly from the
cable. The apparatus also includes a voltage generator and a control device. It
is grounded so that negatively charged particles are attracted to deck surfaces.
The '667 patent discloses an apparatus similar to the one disclosed in the '289
patent which applies positive voltage to one electrically conducive cable and
negative voltage to a second electrically conducive cable in order to control
static charge, eliminate arching, and control net ion flux in animal or poultry
zones.
Saurenman (U.S. Pat. No. 4,326,454['454]-Apr. 27, 1982) discloses
ion dispensers which are supported on an extended carrier that defines the
electrostatically charged surfaces. An extended metallic surface, that can be
grounded, may be associated with the carrier surface. This metallic surface may
be defined by the wall of the chamber containing the dispenser.
While
various systems have been developed for dust reduction, including reduction of
airborne transmission of disease, there remains a need in the art for a more
effective system for reducing dust levels which in turn reduces microbial
contamination using negative air ionization with a ground plane for enhancement
of ion generation. The system can also include a liquid dust collection system
which does not lose efficiency with time, even when exposed to large
concentrations of dust. The present invention is different from the related art
systems.
SUMMARY OF THE INVENTION
It is therefore an object of
the present invention to provide a dust reduction system 40 for reducing air
borne contaminants in enclosed spaces, such as for example rooms, poultry
hatching cabinets, etc., that includes at least one negative air ion generator
50 that has at least one ionizing needle 3 and a ground plane 4 perpendicular
and proximate to the at least one needle 3.
Another object of the
present invention is to provide a dust reduction system 40 for reducing air
borne contaminants which has about 3-12 ionizing bars 11 each containing a
plurality of ionizing needle electrodes 3 and a ground plane 4 parallel and
proximate to said bars 11.
A further object of the present invention is
to provide a dust reduction system 40 for reducing air borne contaminants that
further includes a grounded dust collection system.
Another object of
the present invention is to provide a dust reduction system 40 for reducing air
borne contaminants that includes at least one negative air ion generator 50
including at least one ionizing electrode 3 and a ground plane 4 perpendicular
and proximate to at least one electrode 3 to create an electrostatic field which
reduces air borne contaminants without formation of an arc.
A further
object of the present invention is to provide a dust reduction system 40 for
reducing air borne contaminants that includes at least one negative air ion
generator including at least one ionizing needle 3 and ground plane 4; wherein
at least one needle 3 and ground plane 4 can be positioned perpendicular and at
least close enough without creating arcing and up to as far apart while still
producing an electrostatic field which produces charged particles capable of
reducing air borne contaminants, a non-conductive frame for supporting the at
least one ionizing needle 3 and ground plane 4, a dc power source for supplying
a voltage which is capable of inducing the electrostatic field, especially one
of at least about -15 kV dc, and at least one dust collection device.
A
still further object of the present invention is to provide a method for
reducing air borne contaminants in contained spaces that includes placing at
least one negative air ion generator 50 in an area of a ventilated enclosed
space where air moves in the space past generator 50, dispensing negative ions
from the at least one ion generator 50, charging air borne particles with
negative air ions, and collecting the charged particles with a grounded
collection device.
Further objects and advantages of the invention will
become apparent from the following description.
BRIEF DESCRIPTION OF THE
DRAWINGS
FIG. 1 illustrates negative air ion generator 50 showing
ionizer bars 11, electrodes 3, ground plane 4, frame 6, ground wire 5, high
voltage insulated wires 2, and electrical splice connector 1.
FIG. 2
illustrates system 40 including frame 6 with legs, dust collection device 8 with
water and optional degreaser 7.
FIG. 3 illustrates hatching cabinet 9
including ventilation and recirculation fan 10, air inlet flow control damper
12, air outlet flow control damper 14, electrical controls 16, guide rails 18;
and system 40 including bars 11, ground plane 4, frame 6 and dust collection
device 8 with water and degreaser 7.
FIG. 4a illustrates hatching
cabinet 9 including ventilation and recirculation fan 10, air inlet flow control
damper 12, air outlet flow control damper 14, electrical controls 16, guide
rails for hatching trays 18, ionizer bars 11, ground plane 4, and non-conductive
frame 6.
FIG. 4b illustrates hatching cabinet 9 including electrical
controls 16, guide rails for hatching trays 18, water spray nozzles 20, metal
splash guard 22, metal dust collector plate 24, trough and drain 13, ionizer
bars 11, and frame 6.
FIG. 5 illustrates controlled environment room 34
including room air outlet 26, cages 28, room exhaust register 30, room door 32;
and ionization bars 11, ground plane 4, and frame 6.
FIG. 6 is a log
chart showing effects of treatments on particle counts for the 3 bar ionizer
configuration in the hatching cabinet with ambient air. Particle size is in
microns. The curves represent a running average of 5 samples to improve
discrimination of the curves for the larger particle size ranges.
FIG. 7
is a linear chart showing effects of treatments on particle counts for the 3 bar
configuration in the hatching cabinet with ambient air. Particle sizes are in
microns.
FIG. 8 is a bar graph showing efficiency and mean particle
count for the 3 bar configuration treatments in the hatching with ambient air.
Particle sizes are in microns.
FIG. 9 is a log chart showing effects of
treatments on particle counts for the 6 bar configuration in the hatching
cabinet with ambient air. Particle sizes are in microns.
FIG. 10 is a
linear chart showing effects of treatments on particle counts for the 6 bar
configuration in the hatching cabinet with ambient air. Particle sizes are in
microns.
FIG. 11 is a bar graph showing efficiency and mean particle
count for the 6 bar configuration in the hatching treatments with ambient air.
Particle sizes are in microns.
FIG. 12 is a graph showing comparison of
particle removal efficiency for the 3 bar and 6 bar configurations to that of a
95% media filter with ambient air.
FIG. 13 is a graph showing hourly
dust concentration during hatching with and without system 40, and reduction
efficiency.
FIG. 14 is a graph showing average particle count reduction
efficiency by day during hatching for 3 particle size ranges.
FIG. 15 is
a graph showing average particle count and reduction efficiency during hatch for
all size ranges measured.
FIG. 16 is a photograph showing smoke
diffusion over a grounded water tray; with system 40 off.
FIG. 17 is a
photograph showing smoke diffusion with generator 50 on over a grounded water
tray.
FIG. 18 is a photograph showing smoke diffusion below a suspended
generator 50 with generator 50 on.
FIG. 19 is a photograph showing smoke
diffusion below a suspended generator 50 with generator off.
FIG. 20 is
a graph showing system 40 effects on airborne bacteria.
FIG. 21 is a
graph showing system 40 effects on airborne bacteria.
FIG. 22 is a graph
showing Salmonella transmission based on 7 day old chicks from a hatching
cabinet treated with system 40.
FIG. 23 is a graph showing a smoke test
in a room of a building with and without generator 50.
FIG. 24a
illustrates the layout of ion generators 50 in a large commercial hatching
cabinet showing ionizer bars 11, needle electrodes 3, ground plane 4, air
handling unit 51, cooling coils 52, and fan 10.
FIG. 24b is a top view
of ground plane 4 and ionizer bars 11 in front of fans 10 of a large commercial
hatching cabinet.
FIG. 25 illustrates two dust collection systems
attached to back of a large commercial hatching cabinet showing nozzles 20,
metal dust collector plate 24, trough and drain 13, hatching cabinet exhaust
port 23, and one ion generator including ionizing bars 11 and ground plane 4
attached to air handling unit 51 that includes cooling coils 52, fan 10 and air
inlet duct 54.
FIG. 26 is a graph showing dust concentration for an
ionizer treated commercial hatcher versus a control hatcher, each with 14,500
eggs.
DETAILED DESCRIPTION OF THE INVENTION
Dust reduction
system 40 described herein, while exemplified for poultry production, can be
used in any enclosed space where reduction of airborne particulates such as, for
example, dust, smoke, microorganisms, etc., is desired. For example, significant
reduction of the dust level in areas containing hatching and/or newly hatched
poultry should significantly reduce airborne transmission of disease to the
newly hatched chicks, since studies have shown that salmonella can be
transmitted through the air, especially in hatching cabinets. For purposes of
the present invention, the term poultry includes any species raised for human
consumption, such as for example, chickens, turkeys, ducks, quail, emu, etc.
Dust reduction system 40 (FIGS. 2-4) includes at least one non-absorbent
negative air ion generator 50 (FIG. 1). A strong space charge on dust particles
is created in an enclosed space causing subsequent precipitation, attraction,
and capture of these particles. These particles can be captured in a grounded
dust collection device, such as for example elements 8 and 24 shown in FIGS.
2-4, as well as on most surfaces such as walls and floors, for example. The dust
collection device 40 includes water and optionally a degreaser composition.
Negative air ion generator 50 is made up of a plurality of ionizer bars
11 with needle electrodes 3 (Inner Bar Assembly, Part Number 4101229, The Simco
Company, 2257 North Penn Road, Hatfield, Pa. 19440-1998, for example) and ground
plane 4 proximate to bars 11. Negative air ion generator 50 is operated at
approximately -15,000 to approximately -30,000 volts dc, with approximately -30
kV dc preferred. However, any voltage producing space charges which cause
reduction of airborne contaminants can be used. The number of bars 11 and length
of each bar 11 per generator 50 is dependent on the desired space charge
magnitude and the size of the enclosed space to be treated, determination of
which is well within the ordinary skill in the art based on the present detailed
description. It is preferred to use approximately 3-12 bars for most
applications. For purposes of the present invention, an enclosed space is
defined as any area surrounded by a material layer; such as for example a room
or cabinet with four walls, floor, and ceiling. For example, generator 50
consisting of about six approximately 20" long bars 11 with electrodes spaced
about every 0.5 inch on each bar 11 will treat a volume of about 3200 ft.sup.3
with moderate to heavy dust loads (approximately 27 ft.sup.3 of volume/ft of bar
Each bar 11 has a high voltage insulated wire 2 which runs down the center of
bar 11 and connects to the unexposed ends of the electrodes which are inserted
into bar 11. Bars 11 are arranged so that insulated wire 2 for each bar 11 exits
on the same side of each bar 11. All wires 2 are connected to an electrical
splice connector 1 which in turn connects to an insulated wire from a high
voltage negative dc power supply (not shown) typically located within
approximately 10-30 feet of generator 50. For hatching cabinet applications, the
wire to the power supply is routed through the wall of the cabinet to the power
supply. For room size applications, the wire to the power is routed through a
room wall to a power supply on the outside of the treated space.
Placement of a ground plane 4 in close proximity to bars 11 creates a
strong electrostatic field which in turn charges particles in the vicinity of
generator 50. Bars 11 can be positioned at least as close as possible to ground
plane 4 without creating an arc to as far away from ground plane 4 as possible
while still maintaining an electrostatic field strong enough to produce charged
particles which reduce air borne contaminants. The closer ground plane 4 is to
bars 11, the stronger the electrostatic field will be and the more effective the
dust removal will be, however, the distance must be far enough apart to prevent
arching. With a supply voltage of about -15 kV to -30 kV, they can be placed as
close as about 3 inches away from plane 4. Ground plane 4 is any flat,
electrically conductive material which can be connected to an electrical ground.
It can be, for example, a solid plate, a grid made up of heavy welded wire, a
section of expanded metal, etc. If a grid is used, any size grid is useable, the
smaller the grid size the stronger the electrical field. Examples of materials
that are useful include conductive metals such as for example aluminum, steel,
brass, etc. A preferred embodiment is a grid ground plane 4 of heavy gauge bare
wire with approximately 1.times.1 inch openings to allow for air circulation
through plane 4. Air currents are used to distribute the negative air ions
throughout the space to charge airborne dust. The charged particles can be
circulated past a grounded dust collection device, such as for example elements
7 and 8 or 13,20,22 and 24 (FIGS. 2-4), which traps a large percentage of the
particles. It is preferable that ground plane 4 have a slightly greater area
than that of bars 11 layout. Attached to ground plane 4 at any edge is ground
wire 5.
Bars 11 and ground plane 4 are attached to a non-conductive
frame 6. Frame 6 can be of any configuration to support bars 11 and ground plane
4 without impeding the function of ion generator 50 while fitting into the space
where it will be inserted. It can be constructed of any non-conductive material
such as for example PVC, plastic, glass, ceramic, etc. Generally, a
rectangular-shaped frame made of PVC piping which extends the length of ground
plane 4 and is narrower than bars 11, is sufficient to support bars 11 and plane
4. For some uses where required, the frame can include support legs attached to
the corners of the frame.
Dust reduction system 40 may include a
grounded dust collection device for some applications. On embodiment for use in
small commercial hatching cabinets includes a grounded water tray 8 placed in
the bottom of cabinet 9 (FIG. 3). A second upper tray 8 is located beneath bars
11 and ground plane 4 which are attached to frame 6. Typically, frame 6 with
legs sits in upper tray 8 (FIG. 2). Trays 8 are filled to a depth of at least
about one inch with water and a degreaser composition. The degreaser composition
for the purposes of this invention is anything which helps wet the collected
particles allowing them to settle to the bottom of the dust collection device,
such as, for example, common liquid dishwashing detergents. The degreaser is in
amounts effective to wet the particulates captured by the dust collection device
so that the particulates settle to the bottom of the device instead of floating
on top of the water surface. Typical degreaser concentration used in the liquid
solutions is approximately about 2 to 3%. The amount of the water degreaser
composition should be enough so that the composition does not evaporate
completely before the hatching process is completed.
Another embodiment
of grounded dust collection device, typically used in large commercial hatching
cabinets, includes grounded metal dust collector plates 24 attached to the back
wall of hatching cabinet 9 with water spray nozzles 20 which are mounted above
or beside plate 24, and negative air ion generator 50 (FIG. 4b). Trough and
drain 13 for plate 24 rinse water is located on the floor of cabinet 9. Plate 24
serves as a grounded metal dust collector and is made of any type of metal. It
is preferable that the size of plate 24 is about one-fourth the total area of
the four walls of cabinet 9. It is preferable to attach plate 24 flush to the
rear of hatching cabinet 9 using any type of hanging means, such as for example
hangers, screws, brackets, etc. Spray nozzles 20 are placed along the top of
plate 24 or along the side of plate 24 approximately 8-10 inches apart.
Generally, a plate of approximately 48 inches in width require at least about 5
nozzles. Alternatively, any means for applying water to rinse plate 24 can be
used. For example, a pipe such as a PVC pipe, with holes drilled approximately
every 2 inches can be attached to the top of a hatching cabinet so that water
from the drilled holes will trickle down plate 24. The nozzles or pipe are
operatively attached to a manifold and solenoid valve (not shown). The solenoid
valve is controlled by the cabinet humidity control which causes water to be
applied to collector plate 24 when cabinet humidity drops below a set point of
typically about 55%. This raises the humidity to the set point and functions to
moisten and rinse plate 24. In some applications, the solenoid valve is also
operated by a time proportioning controller to assure that the plate is rinsed
at least about every 30 minutes. Moisture on grounded plate 24 helps collect
charged dust particles more effectively and each new rinse event helps rinse
collected dust into trough and drain 13 (FIGS. 4b and 25). Depending on the air
circulation in a hatching cabinet, spray nozzles or pipe can mounted along the
side of plate 24 such that water is applied sideways rather than downward.
Nozzles 20 or pipe with holes can be attached by any means. In the case of
nozzles 20, the nozzles are at least about 3-6 inches from plate 24 allowing the
spray angle of nozzles 20 to be adjustable towards the sheet.
For large
ventilated enclosed spaces such as rooms, a controlled environment poultry
rearing room 34 for example, ground plane 4 and the room surfaces serve as a
dust collection device.
For small commercial hatching cabinets, one
configuration for system 40 includes ionizer bars 11 proximate to ground plane 4
and at least two grounded dust collection devices containing water and a
degreaser 7 (FIGS. 2 and 3). Ground plane 4 is made up of a heavy gauge wire
grid with approximately 1.times.2 inch openings. Bars 11 and ground plane 4 are
supported by frame 6. Frame 6 is generally rectangular in shape with legs 6
attached near the corners. Frame 6 with legs is placed into an upper grounded
water tray of hatching cabinet 9 and serves as grounded dust collection device.
Tray 8 slides into the cabinet using the top set of guide rails 18. Water and
degreaser 7 are added to tray 8 to a depth of at least about 1 inch (FIG. 3).
All rails and metal parts in the cabinet are grounded. Another tray 8 with water
and degreaser 7 is placed on the floor of the cabinet. Hatching cabinet 9
includes ventilation and recirculation fan 10 and air inlet flow control damper
12 located on the door of cabinet 9. It also includes air outlet flow control
damper 14 and electrical controls 16 for the hatching cabinet located externally
on the top of cabinet 9. For larger commercial hatching cabinets the dust
collection device described above that includes metal dust collector plate 24, a
means for applying water to plate 24 and a trough and drain 13 is typically
used.
For large ventilated enclosed spaces such as rooms, a controlled
environment poultry rearing room 34 for example, negative air ion generator 50
is positioned near the ceiling of the room proximate to the room air
distribution outlets 26 such that air from outlets 26 flows across the ionizer
bars 11 and distributes charge throughout the room (FIG. 5). It is preferred
that generator 50 is located near the center of the room and well away from
exhaust outlet 30 to maximize the operation of generator 50. The farther the
distance, the greater the opportunity for the treated air to charge airborne
dust and precipitate it or cause it to adhere to surfaces in the room before it
is exhausted. In this embodiment, generator 50 includes bars 11 with needle
electrodes 3, ground plane 4 proximate to bars 11, and frame 6. Ground plane 4
and the room surfaces in this embodiment, serve as dust collection device.
In operation, generator 50 is placed in an upper area of an enclosed
space and operated continuously at about -20,000 to -30,000 V dc to generate a
negative electrostatic charge throughout the space. For small ventilated
enclosed spaces such as hatching cabinets, for example, generator 50 is placed
above the top hatching basket and fertile eggs are transferred into hatching
cabinet 9 at about 18 days after incubation has been initiated. In the
embodiment employing a dust collection device with trays 8, an aqueous
composition containing a degreaser is added to tray 8 which is placed on the
floor of the cabinet as a dust collection device. When frame 6 has legs, the
frame can be set into another tray 8 containing an aqueous composition
containing a degreaser and located in the top of the cabinet. This tray is the
supported by the guide rails 18 located in the upper portion of cabinet 9. For
embodiments employing a dust collection device that includes a metal dust
collector plate 24 and a means for applying water to plate 24, a solenoid valve
controlled by the cabinet humidity control or by a timer, causes water to be
applied to plate 24 to rinse it. Generator 50 is operated continuously at about
-20,000 to about -30,000 V dc to generate a negative electrostatic charge
throughout the cabinet from transfer through hatching on day 21. System 40 is
cleaned at the end of each hatching period.
For rooms, such as for
example poultry rearing rooms, generator 50 is placed near the ceiling of the
room near the air distribution outlets and is operated continuously as needed.
When used in poultry rearing rooms, ground plane 4 and bars 11 need to be
cleaned about every 2 to 3 days to maintain efficient operation due to
accumulation of dust.
The following examples illustrate the use of the
invention for reducing airborne particulates in poultry hatching cabinets and
rooms. They are intended to further illustrate the invention and are not
intended to limit the scope of the invention as defined by the claims. Multiple
or expanded units, using the same principles can be used for reduction of
airborne contaminants in larger ventilated spaces.
EXAMPLE 1
This example was conducted in a SurePip incubator which had an interior
volume of 1.33 m.sup.3, and a ventilation rate of approximately 0.13 m.sup.3
/min. The interior of the SurePip cabinet is constructed of fiberglass coated
Styrofoam panels except for the floor, door frame, and humidifier drip tray
which are aluminum. Two configurations of ion generator 50 were used:
1.
A 3-bar configuration with approximately 35.6 cm long bars 11 constructed out of
TEFLON with needle electrodes 3 spaced approximately every 1.23 cm and attached
to a non-conducting PVC frame 6.
2. A 6-bar configuration with
approximately 50.8 cm bars 11 constructed out of TEFLON with needle electrodes 3
spaced approximately 1.25 cm and attached to a non-conducting PVC frame.
Generator 50 configurations were positioned such that the tips of
electrodes 3 were about 8.9 cm below ground plane 4 with electrodes 3 facing
downward. The aluminum drip tray at the top of cabinet 9 served as ground plane
4 for the 3 bar configuration and a heavy gauge welded steel wire grid with
about 2.5.times.5 cm openings served as ground plane 4 for the 6 bar
configuration. Generator 50 was operated at about -20 kV dc.
Particle
counts were made with a Climet CI-500 laser particle counter (Climet
Instruments, Inc., 1320 W. Colton Ave., Redlands, Calif. 92374) in six ranges:
about 0.3-0.5, about 0.5-1.0, about 1.0-5.0, about 10.0-25.0 and about >25
microns; at a sampling rate of about 2.8 L/min (0.1 ft.sup.3 /min). Since
ambient dust counts in the inhalable range are typically quite high (See
Generator off Interval on FIGS. 6-8) and consistent over a period of several
hours, the initial testing of generator 50 efficiency was conducted using
ambient air.
The following procedure for 2 reps was as follows:
1st interval (.apprxeq.30 min): Begin measurements for about 30 min with
the incubator door open and the generator 50 off to allow for complete
infiltration of ambient air.
2nd interval (.apprxeq.60 min): Close
hatcher door, turn hatcher fan 10 on, and turn generator 50 on.
3rd
interval (.apprxeq.60 min): Turn hatcher fan off (generator 50 still on, door
shut)
4th interval (.apprxeq.30 min): Everything off, stop measurements
at end of this interval.
Hatcher 9 was operated at ambient temperature
and humidity to determine the effect of negative air ion generator 50 alone for
reducing dust levels. During normal operation, hatcher 9 operates at
37.8.degree. C. and 55% relative humidity (RH) with humidity controlled by a
misting nozzle 20 which would add to the particle count even though it would
probably reduce the actual dust level. A 51 cm W.times.82 cm L.times.4 cm H
sheet metal tray, normally used to catch excess water generated during
humidification, was used as dust collection device in the bottom of the hatcher
and was filled with about 2 cm of water and connected to an earth ground to
provide a sink for the negatively charged dust particles as they were
recirculated by the hatcher fan 10.
Results are shown in FIGS. 6-8 and
Table 1 for the 3 bar configuration and FIGS. 9-11 and Table 1 for the 6 bar
configuration. Significant (P.gtoreq.0.05) reductions in particle counts were
achieved with the 6 bar configuration which removed particles with efficiencies
which averaged about 92.9% for particles up to about 10 microns and about 90.8%
for particles of about 10 microns and larger. Significant (P.ltoreq.0.05)
reductions in particle counts were also achieved with the 3 bar configuration
which had an average particle reduction efficiency of about 80.1% for particles
up to about 10 microns and larger. Most of the dust reduction by negative air
ion generator 50 occurred within about 5 minutes of the time the generator 50
was turned on (FIGS. 6-7 and 9-10).
Substantial further reduction was
obtained when the hatcher cabinet blower was turned off while generator 50 was
still on (3rd interval, FIGS. 6-7 and 9-10), suggesting that the blower was
reentraining an amount of dust equal to the count difference between the blower
on and blower off conditions. This additional reduction for the 3 bar
configuration is shown in FIG. 8 and Table 1 below. It resulted in particle
counts which were significantly (P.ltoreq.0.05) lower than counts resulting from
generator 50 alone for particles up to about 25 microns. The effect of turning
the blower off for the 6 bar configuration is shown in FIG. 11 and Table 1 which
resulted in significantly (P.ltoreq.0.05) lower particle counts than generator
50 alone for particles up to about 1 micron and non-significant reductions
(P>0.05) for particles above 1 micron. Combining the effects of generator 50
with the effect of reduced reentrainment with the blower off resulted in an
overall average reduction of about 99.7% for the 3 bar configuration with Blower
Off, and about 98.8% for the 6 bar configuration with Blower off (FIGS. 8 and
11). Particle counts during the 4th interval (hatcher blower and generator 50
off) increased to several times those of the 3rd interval (blower off, generator
50 on).
The efficiencies of generator 50 are compared in FIG. 12 to that
of a 95% media filter in a series filter system (35% filter followed by 95%
filter) described by Mitchell et al. (Avian Diseases, Volume 33, 792-800, 1989)
for filtering incoming air to filtered-air positive pressure (FAPP) houses used
to raise disease-free chickens. The overall efficiency of the 6 bar
configuration was very close to that of a 95% media filter (92.2% vs. 91.5%).
Note that airborne viruses are usually found on particles between about 3 and 6
microns and airborne bacteria are mostly found on particles of about >6
microns(Hugh-Jones et al., J. Hyg., Camb., Volume 71, 325-339, 1973).
Preliminary measurements of dust generated in an operational hatching cabinet
during the hatching period from day 18 to day 22 showed substantial increases
over ambient levels of dust particles in the sizes up to about 10 microns.
TABLE 1
__________________________________________________________________________
Treatment
0.3-0.5
0.5-1
1-5 5-10 10-25
>25
__________________________________________________________________________
3 - Bar Control
45,996,570.sup.a
1,992,544.sup.a
195,696.sup.a
12,755.sup.a
933.3.sup.a
39.22.sup.a
3 - Bar Ionizer 6,563,364.sup.b 345,764.sup.b 46,741.sup.b 3,063.sup.b
238.5.sup.b 3.18b
On, Fan On
3 - Bar Ionizer 288,436.sup.c 13,096.sup.c 508.3.sup.c 3.18.sup.c
0.00.sup.c 0.00.sup.b
On, Fan Off
6 - Bar Control 69,822,270.sup..sup.a 8,694,955.sup.a 364,928.sup.a
37,655 .sup.a 4,606.3.sup.a 133.1.sup.a
6 - Bar Ionizer 7,467,009.sup.b
827,220.sup.b 22,779.sup.b 1,808.4.sup.b
204.4.sup.b 18.6.sup.b
On, Fan On
6 - Bar Ionizer 554,316.sup.c 55,421.sup.c 1,433.2.sup.b 26.1.sup.b
13.1.sup.b 6.5.sup.b
On, Fan Off
__________________________________________________________________________
Duncan's Range Analysis results of mean particle particles per m.sup.3 by
treatment and ionizer type. Means with different or nonoverlapping
superscript letters are significantly different (P .ltoreq. 0.05).
EXAMPLE 2
Duplicated experiments were conducted in an
operational hatching cabinet, and particle size distribution and concentration
were measured during the hatching process to characterize the amount and sizes
of airborne particulate and the effectiveness of an electrostatic space charge
on reducing airborne particulate matter in the hatching cabinet. An ion
generator 50 with a 6 bar 11 configuration was suspended above the top hatching
basket within a Natureform (NMC200) hatching cabinet 9 that was approximately
50% full of 18 day-old fertile broiler eggs containing developing embryos. Ion
generator 50 operated continuously at about -20,000 V dc to generate a strong
negative electrostatic charge throughout the cabinet from transfer through
hatching on Day 21. Dust was collected in 2 grounded trays 8 containing
approximately 1.5 inches of water and between about 2-3% of liquid JOY
dishwashing detergent. One tray 8 was suspended above the top egg basket in the
cabinet and a second tray 8 was placed on the floor of the hatching cabinet 9.
Particle count measurements were made at sampling intervals of about 15
minutes with a Climet CI-500 laser particle counter in 6 ranges: about 0.3 to
0.5, about 0.5 to 1.0, about 1.0 to 5.0, about 10.0 to 25.0 and about >25
microns; at a fixed rate of about 2.83 Liters/minute (about 0.1 ft.sup.3
/minute). Dust concentration was measured at sampling intervals of about 2
minutes with a TSI DustTrak instrument at about 1.7 Liters/minute. The DustTrak
had a range of about 0.001 to about 100 mg/m.sup.3. The sampling tubes for the
CI-500 and the DustTrak were located inside the hatching cabinet along the left
side, midway between the ceiling and floor, and between the side wall and the
sides of the hatching baskets.
Generator 50 effects are shown in FIG. 13
for dust concentration and FIGS. 14-15 for particle counts. Dust removal based
on dust concentration (FIG. 13) shows efficiencies ranging from about 100% in
the early stages of hatch to about 80% near the end. The drop with time may be a
result of the heavier dust load as more birds hatch out. Particle size reduction
seemed to follow the same trend with efficiencies averaging about 98.7% on day
19 to about 82.8% on day 21. Particle count data and reduction efficiency are
shown in FIG. 15. The efficiency of ion generator 50 for removing ambient dust
is compared to that of a 95% media filter on FIG. 12 and it clearly indicates a
favorable performance for generator 50 since 95% filters have been shown to
block airborne transmission of Newcastle disease virus (Hopkins and Drury, 1971,
supra). Effects of generator 50 used in this example on smoke generated by a
smoke stick are shown in FIGS. 16-19. In FIGS. 16 and 17, with generator 50
sitting on top of a grounded water tray, turning generator 50 on (FIG. 17)
causes the smoke to be drawn to the water while generator 50 off state (FIG. 16)
causes the smoke to diffuse into the room. In FIGS. 18 and 19 with generator 50
suspended several feet above the floor, turning generator 50 on (FIG. 18) causes
the smoke to be drawn to the ground plane 4 (just above the ionizer bars 11) and
appear to disappear while generator 50 off state (FIG. 19) allows the smoke to
diffuse into the room. These visual results correspond to the effects seen in
the hatching cabinets when generator 50 was turned on.
EXAMPLE 3
Three trials were conducted to evaluate the effectiveness of an
electrostatic space charge on the levels of total aerobic bacteria (TPC) and
Enterobacteriaceae (ENT) within the hatching cabinet. A negative air ion
generator 50 was placed above the top hatching basket within a Natureform
(NMC200) hatching cabinet that was approximately 50% full of 18-day-old broiler
eggs containing developing embryos as described above in Example 2. Generator 50
operated continuously at -20,000 volts dc to generate a strong electrostatic
charge throughout the cabinet from transfer through hatching on day 21. Dust was
collected in grounded trays 8 containing water and between about 2-3% of JOY
dishwashing detergent as described above in Example 2. An adjacent hatching
cabinet served as a nontreated control. Air samples were collected daily by
inverting brain heart infusion agar plates for TPC and violet red bile agar
plates with the addition of 1% glucose plates for ENT over the exhaust air vent
of the hatching cabinets for approximately five minutes. Plates were incubated
at approximately 35.degree. C. for about 48 hours. Approximately 10 chicks were
sampled from each hatching basket on about day 21 and grown out to about 7 days
of age in isolation cabinets. At about 7 days, the chick cecas were collected
and assayed to determine whether they were positive for Salmonella.
Results are shown in FIGS. 20-22. Overall, treatment with generator 50
reduced bacteria counts for total aerobic bacteria and Enterobacteriaceae by
about 90-99%, compared to the nontreated control values (FIGS. 20-21). Trials 1
and 5 where generator 50 was turned off prior to the chicks being removed
resulted in no significant reduction of positive chicks at 7 days of age for the
treated (generator) vs. the non-treated cabinets since turning generator 50 off
prior to chick removal caused contaminated dust to fall into the cabinet (FIG.
22). In Trial 6 where ion generator 50 was not turned off until chicks were
removed, the treatment cabinet had no positive chicks and the control cabinet
had 8 positive chicks (FIG. 22).
EXAMPLE 4
The effectiveness of
an ion generator 50 with six ionizer bars 11 with attached ground plane 4 was
tested in an animal room with floor dimensions of approximately 15 ft..times.22
ft. and a volume of about 484 ft.sup.3. Preliminary duplicated tests involved
the use of a chemical smoke stick that was discharged inside of a treated room
with generator 50 running at -30 kV dc and left there for 30 minutes before it
was removed. The same smoke exposure was made to an untreated (control) room.
Particle count measurements were made at sampling intervals of about one minute
with a Climet CI-500 laser particle counter in the 6 ranges described above in
Example 2 at a fixed sampling rate of about 2.83 L/minute (0.1 ft.sup.3). Dust
concentration was measured at sampling intervals of about one minute with a TSI
DustTrak instrument which sampled at about 1.7 L/minute. The DustTrak has a
range of about 0.001 to about 100 mg/m.sup.3 and a resolution of about 0.001
mg/m.sup.3. Measurements of dust concentration and particle counts were made for
about 60-70 minutes.
Results are shown in FIG. 23 for dust
concentration. The average dust reduction of the treated room compared to the
control room during the approximately 30 minute period when the smoke stick was
in the room (high concentration-average dust concentration is approximately more
than four times higher than that in a typical occupied poultry room or in a
hatching cabinet) was approximately 72%. For the approximately 30 minute period
when the smoke stick was out of the room (moderate concentration-average dust
concentration is similar to that in a typical poultry room or in a hatching
cabinet), the treatment reduction efficiency was approximately 91%. In a later
experiment in the same room with mature caged layers infected with Salmonella
enteritidis (SE), air samples taken with petri dishes showed generator 50
treatment reduced SE counts by an average of about 82% during the approximately
three days following cleaning of generator 50. During this same period, SE
counts in the treatment room on 12 plates per day exceeded 1 colony of SE per
plate only once compared to about 18 times in the control room.
EXAMPLE
5
The effectiveness of ion generator 50 with 12 ionizer bars 11 with
attached ground plane 4 was tested at approximately -30 kV in a commercial
hatching cabinet in a commercial hatchery (FIG. 24). The cabinet was
approximately 130" wide, 65" deep and 74" high. Ground plane 4 is a grid ground
plane with a grid size of approximately 1 inch by 1 inch. It is attached
approximately three inches from ionizing bars 11. Two generators 50 are mounted
in the cabinet 9 each approximately 1/2 inch in front of fans 10, which are
located in front of cooling coils and heating elements 52, by attaching frame 6
to air handling unit 51 of cabinet 9. Each generator 50 has a dust reduction
system 40 including five spray nozzles 20 mounted above and approximately 1 inch
in front of a metal dust collection plate 24 which is attached to the back wall
of cabinet 9 each next to a hatching cabinet exhaust port 23 (FIG. 25). A trough
and drain 13 is located below plate 24 on the floor of cabinet 9 to collect
water and dust from metal plate 24.
Generator 50 was operated
continuously at about -30 kV to generate a strong negative electrostatic charge
throughout the hatcher from transfer of eggs on day 18 through hatching on Day
21. Dust was collected on the hatcher surfaces including ground plane 4. It was
loaded to its capacity of 14,500 fertile 18-day-old eggs. Dust concentration
measurements were performed as in Example 2 using a TSI DustTrak. The DustTrak
has to be cleaned daily to prevent plugging. Dust measurements in two duplicated
trials from day 18 until hatch at day 21 demonstrated significant dust reduction
due to the ionizer treatment compared to the control cabinet. Results, shown in
FIG. 26, show very significant reductions in dust.
The foregoing
description is for the purpose of illustration. Such detail is solely for that
purpose and those skilled in the art can make variations therein without
departing from the spirit and scope of the invention.
INDEX OF THE
ELEMENTS
1. Electrical Splice Connector
2. High Voltage
Insulated Wire
3. Needle Electrode
4. Ground Plane
5.
Ground Wire
6. Non-Conductive PVC Frame
7. Water and Degreaser
Solution
8. Grounded Water Tray
9. Hatching Cabinet For Fertile
Poultry Eggs
10. Ventilation and Recirculation Fan
11. Ionizer
Bars
12. Air Inlet Flow Control Damper
13. Trough and Drain for
Back Plate Rinse Water
14. Air Outlet Flow Control Damper
16.
Electrical Controls for Hatching Cabinet
18. Guide Rails for Plastic
Hatching Trays (Grounded)
20. Water Spray Nozzles for Metal Dust
Collector Plate
22. Metal Splash Guard for Spray Nozzles
23.
Hatching Cabinet Exhaust Port
24. Metal Dust Collector Plate
26.
Room Air Outlet
28. Cages for Poultry Layers
30. Room Exhaust
Register
32. Room Door
34. Controlled Environment Poultry
Rearing Room
40. Dust Reduction System
50. Negative Air Ion
Generator
51. Air Handling Unit
52. Cooling Coils and Heating
Elements
54. Air Inlet Duct
56. Floor
* * * * *
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