Mini-cyclone biocollector and concentrator

Information

  • Patent Grant
  • 6468330
  • Patent Number
    6,468,330
  • Date Filed
    Wednesday, June 14, 2000
    24 years ago
  • Date Issued
    Tuesday, October 22, 2002
    21 years ago
Abstract
The particle separation and collection assembly uses cyclonic forces to separate and remove large particles from an airstream and concentrate small particles for sensor/detector technology. This assembly utilizes multiple mini cyclones operating in parallel to reduce the size and velocity of air through the cyclone inlets while maintaining the same fluid or flow rate as compared to one large cyclone. The multiple cyclone system can be arranged in a radial geometry or in a bipolar or uni-polar longitudinal design. The particle separator and collection assembly uses a blower or vacuum pump to draw outside gas into the cyclone particle separator assembly through radial inlets. Vacuum transfer channels, extending the entire length of the assembly, pull gas into the top of the cyclone chambers and out through the bottom apex of cyclone chamber and through the top vortex finder. Gas entering the cyclone particle separation chambers from the inlet swirls downwardly through cyclone chambers due to the tangentially aligned inlet. The gas travels in a helical pattern downwardly toward the bottom of cyclone chambers. Some of the air carrying particles smaller than the cut reverses direction and leaves the cyclone through the top vortex finder. The rest of the air exits the cyclone at the bottom. The geometry of the cyclone determines particle “cut” size. Due to centrifugal forces, the particles larger than the “cut” size flow outwardly away from the center axis of the chambers and toward the walls of the respective chambers. Liquid is pumped into chamber from a liquid reservoir through the central liquid passage tube. This liquid wets the particles in chamber and washes down the chamber walls flushing the particles into the reservoir. The liquid is continuously recirculated through the conical chambers by the peristaltic pump thereby concentrating the particles within the liquid over time. The liquid then can be pumped to an optionally integrated monitoring system comprised of detectors and/or sensors. The monitoring system then can send out a warning if toxic microorganisms are present.
Description




FIELD OF THE INVENTION




This invention relates to a particle separator for separating particles from a stream of gas, and in particular to a particle separator using mini-cyclones that separate the particles from the gas stream and concentrate those particles within a quantity of liquid to be collected and monitored.




BACKGROUND OF THE INVENTION




The collection and monitoring of particles separated from a gas is needed in many diverse situations. Some of these situations include defense against biological warfare agents in battlefield and other military applications; and protecting the general public against: airborne pathogenic agents released by terrorist groups; genetically modified material used in biotechnology applications; infectious organisms contaminating air in hospitals, research labs, public buildings, and confined spaces such as subway systems; and pollutant aerosols that damage the respiratory system.




Bioaerosols are defined as airborne particles, large molecules or volatile compounds that are living, contain living organisms or were released from living organisms. The size of a bioaerosol particle may vary from 100 microns to 0.01 micron.




There is an increasing concern about the presence of aerosolized biocontaminants associated with the food processing industry.


E. coli,


salmonella, “Mad Cow” disease and other contaminants have resulted in widespread public concern about the safety of food products. The collection and measurement of bioaerosols are of interest to a wide community of public health officials because they can cause infectious diseases or chemical damage to the respiratory system. These particles are also of concern to the Department of Defense (DOD) because of their possible use in biological warfare and terrorism.




Air quality monitoring is also an important public health need. As the world's population rises exponentially and world travel becomes increasingly easy, the degree and pace at which communicable diseases can spread has resulted in significant concerns regarding potential epidemics from airborne disease transmission. Recirculation of air in buildings and other enclosed spaces such as subways and airplanes has lead to a potentially significant public health issue. Identification and control of infectious disease organisms in hospitals represents another major need. The Environmental Protection Agency cites indoor air pollution causing “sick building syndrome” as one of the five major environmental problems in the United States (Federal Register, Apr. 5, 1994; the regulatory driver for the quality of indoor air as proposed regulations for OSHA). According to the EPA, indoor air pollution affects 33 to 55 percent of commercial buildings, and causes 13.5 million lost work days each year. It can also lead to major public health incidents.




Nosocomial, or hospital-acquired, infections are often caused by antibiotic resistant microorganisms. These infections currently affect around 10% of hospital patients, causing additional suffering and mortality. The detection of pathogenic materials such as nosocomial pneumonia and Legionnaires disease in ventilation systems could help prevent infectious outbreaks of unknown origin in hospitals and public buildings. A miniaturized collection/detection system could easily be placed within the ventilation ducts of buildings and left sampling for an extended length of time.




The use of recombinant microorganisms is an expanding area of biotechnology for production of biochemicals, pharmaceuticals and vaccines. Increasingly, recombinant viral vectors are being used for vaccine delivery and gene therapy. Effective containment measurements are required but there is a need to be able to measure the effectiveness of these containment measures. For example, there is the possibility that aerosols created accidentally by laboratory procedures may escape from the containment provided by microbiological safety cabinets. Or, aerosols may be created by centrifugation, or liquid handling. At present, the means by which airborne viruses and bacteria can be detected and monitored are limited.




Threats from microorganisms in the air as a result of natural phenomena or human-induced activities such as the examples discussed above cannot be adequately monitored and evaluated with current technology. Early warning, hazard recognition, personal protective equipment, exposure evaluation, and environmental monitoring are needed to prevent and reduce impacts from airborne infectious or genetically modified material. Near real-time monitoring is necessary to avoid exposure and to initiate early treatment to arrest disease progression. Existing collection devices such as filters do not provide real time information because they must be taken to a laboratory for analysis. Detection devices for real time use by the military currently are large and power intensive.




A further deficiency with large collectors is that they have high inlet velocities and can severely damage or kill the microorganisms being collected. A high flow rate system that uses one large cyclone chambers requires a high inlet gas velocity for proper efficiency. However, a high inlet gas velocity also creates a large pressure drop across the cyclone chambers that results in a high power consumption. Further, microorganisms usually have to be collected alive for effective detection. The high inlet velocity needed for efficiency places large shear forces against the particles, killing the microorganisms needed alive for analysis.




Therefore, there is a need for small, efficient gas (aerosol) collectors to separate, capture and concentrate bioparticles from the air for detection.




SUMMARY OF THE INVENTION




The particle separation and collection assembly of the present invention uses cyclonic forces to separate and remove small particles from an airstream and concentrate small particles for sensor/detector technology. This system utilizes multiple mini-cyclones operating in parallel to reduce the velocity of the intake air while maintaining the same fluid or flow rate as compared to one large cyclone.




In one embodiment of the present invention, the particle separator and collection assembly comprises a plurality of particle separation chambers; each of the particle separation chambers having a conical shape with an internal surface; a lower vacuum chambers disposed in fluid communication with the particle separation chambers; a plurality of inlets, each inlet disposed in fluid communication with each particle separation chambers, each inlet supplying particle-laden gas external from the assembly to each particle separation chambers; and a liquid passage conduit connectable to a reservoir; the liquid passage conduit supplying a liquid from a reservoir to the internal surface of each particle separation chambers in order to collect the particles separated from the gas within each particle separation chambers.




In an alternate embodiment of the present invention, the particle separator and collection assembly includes a two stage system of concentric components to remove large interfering particles and retain small particles for collection and analysis. In this assembly, a large outer cyclone is used to separate particles >50μ and an inner bank of mini-cyclones is used to capture and concentrate small particles <50μ. The two stage particle separator and concentrator assembly comprises a housing having a longitudinal axis, the housing including a top end portion connectable to a blower and a bottom end connectable to a pump; at least one cyclone chambers disposed within the housing and having an upper end and a lower end; and at least one housing inlet in fluid communication with at least one cyclone chamber, at least one housing inlet enabling particle-laden gas external from the apparatus to enter the at least one particle separation chambers; a liquid passage conduit disposed within the housing and connectable to a pump, the liquid passage conduit delivering the liquid to the upper end of the least one cyclone chambers; and an outer cyclone chambers concentric to the longitudinal axis and coupled to the housing, the outer cyclone chambers in fluid communication with the inlet, wherein particle-laden gas is pulled through the at least one cyclone chambers by a blower so that the particles are separated from the gas by centrifugal force and collected by the liquid supplied to the at least one cyclone chambers.




The present invention further includes a method for separating particles from a gas and collecting the particles within a liquid using a particle separation assembly, the particle separation assembly having a plurality of cyclone separation chambers disposed longitudinally within a housing of the assembly and having a longitudinal axis, the housing including a top end connectable to a blower, a bottom end connectable to a pump, and a plurality of inlets corresponding to the plurality of cyclone separation chambers for external gas to enter the assembly, a liquid passage conduit connectable to the pump for delivering the liquid to each cyclone separation chambers, the method comprising: drawing a particle-laden gas into the inlets of the housing and through the plurality of cyclone separation chambers so that a centrifugal force is created due to the configuration of the chambers; separating the particles from the gas by using the centrifugal force to move the particles outwardly away from the longitudinal axis and toward the inner wall of each cyclone chambers; supplying each cyclone chambers with the liquid through the liquid passage conduit; collecting the particles with the liquid by washing down the inner wall of each cyclone chambers and trapping the particles within the liquid.




The microassembly approach to aerosol collection of the present invention is advantageous by allowing process routes through large surface to volume ratios and short response times. Parallel processing using micro components allows process optimization of a single unit and subsequent scale-up by replication. Miniaturization of components also allows multi-component processing of an airstream for more efficient particle collection and concentration.




It is advantageous using a bank of miniature cyclones (1-3 cm diameter) in parallel. Parallel processing using multiple mini-cyclone chambers reduces the pressure drop across the separation unit significantly while processing the same amount of fluid (same fluid or flow rate) with the same efficiency as one large cyclone chambers. This also provides an assembly that has low power consumption due to lower inlet air velocity. Further, the lower inlet air velocity reduces the shear forces and abrasive wear against the particles and the continuous underfluid or flow commonly associated with the cyclone.




Another advantage of an assembly consisting of multiple mini-cyclones is that of total assembly size and volume. In terms of internal volume, our calculations indicate that a mini-cyclone assembly can be almost an order of magnitude smaller than a single large cyclone. This also benefits assembly weight and fluidic assembly volume. Further, the use of micro-machined, parallel components allows the particle separation and collection system to be assembled into smaller or larger architectures, making it extremely flexible and adaptable for a wide range of possible applications that can be integrated with a number of different biosensor or other detector technologies.











BRIEF DESCRIPTION OF THE DRAWINGS




The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:





FIG. 1

illustrates an exploded, perspective view of the particle separator assembly of the present invention;





FIG. 2

illustrates an enlarged, perspective view of the base section of the present invention;





FIG. 3A

illustrates a top view of the base section of the present invention;





FIG. 3B

illustrates a cross-sectional view of the base section taken along the line I—I of

FIG. 3A

;





FIG. 3C

illustrates another cross-sectional view of the base section taken along the line I—I of

FIG. 3A

;





FIG. 4

illustrates a bottom view of the base section of the present invention;





FIG. 5

illustrates an enlarged, perspective view of the conical cyclone section of the present invention;





FIG. 6

illustrates an enlarged view of the top of the conical cyclone section of the present invention;





FIG. 7A

illustrates a top view of the conical cyclone section of the present invention;





FIG. 7B

illustrates a side elevation view of the conical cyclone section of the present invention;





FIG. 7C

illustrates a bottom view of the conical cyclone section of the present invention;





FIG. 7D

illustrates an end view of the under fluid or flow pipe that is connected to the conical cyclone section of the present invention;





FIG. 7E

illustrates a side elevation view of the under fluid or flow pipe of

FIG. 7D

;





FIG. 8A

illustrates an enlarged, perspective view of the cyclone inlet section of the present invention;





FIG. 8B

illustrates an enlarged, perspective view of the cylindrical cyclone section of the present invention;





FIG. 9A

illustrates a top view of the cylindrical cyclone section of the present invention;





FIG. 9B

illustrates a side elevation view of the cylindrical cyclone section of the present invention;





FIG. 10A

illustrates a top view of the cyclone inlet section of the present invention;





FIG. 10B

illustrates a side elevation view of the cyclone inlet section of the present invention;





FIG. 10C

illustrates an enlarged partial view of the tapered outer wall of the cyclone inlet section of the present invention;





FIG. 11

illustrates an enlarged, perspective view of the upper cyclone vent section of the present invention;





FIG. 12A

illustrates a top view of the upper cyclone vent section of the present invention;





FIG. 12B

illustrates a side elevation view of the upper cyclone vent section of the present invention;





FIG. 12C

illustrates a top view of the underfluid or flow pipe that is connected to the conical cyclone section of the present invention;





FIG. 12D

illustrates a side elevation view of the underfluid or flow pipe that is connected to the conical cyclone section of the present invention;





FIG. 13

illustrates an enlarged, perspective view of the top section of the present invention;





FIG. 14A

illustrates a top view of the top section of the present invention without the flange attachment;





FIG. 14B

illustrates a side elevation view of the top section of the present invention without the flange attachment; and





FIG. 15

illustrates the integration of a blower with the particle separation assembly of the present invention.





FIG. 16

illustrates an exploded, perspective view of the alternative embodiment of the particle separator assembly of the present invention;





FIG. 17

illustrates an enlarged, perspective view of the reservoir section of the alternative embodiment of the present invention;





FIG. 18

illustrates an enlarged, perspective view of the splash guard section of the alternative embodiment of the present invention;





FIG. 19

illustrates an enlarged, perspective view of the cyclone section of the alternative embodiment of the present invention;





FIG. 20

illustrates an enlarged, perspective view of the cyclone section of the alternative embodiment of the present invention;





FIG. 21

illustrates an enlarged, perspective view of the cyclone head section of the alternative embodiment of the present invention;





FIG. 22

illustrates another enlarged, perspective view of the cyclone head section of the alternative embodiment of the present invention;





FIG. 23

illustrates an enlarged, perspective view of the top section of the alternative embodiment of the present invention;





FIG. 24

illustrates an enlarged view of the cyclone head section of the particle separator assembly of the alternative embodiment of the present invention;





FIG. 25

illustrates an enlarged view of the cyclone chambers section of the particle separator assembly of the alternative embodiment of the present invention;





FIG. 26

illustrates an enlarged view of the reservoir section of the particle separator assembly of the alternative embodiment of the present invention;





FIG. 27A

illustrates a top view cross section of the outer particle separator combined with the inner min-cyclone collector of the present invention;





FIG. 27B

illustrates a side perspective view of the outer helical cyclone for the large particle separation of the alternative embodiment of the present invention;





FIG. 27C

illustrates a side perspective view of alternative embodiment of the present invention;





FIG. 28

illustrates an enlarged, perspective view of the alternative embodiment of the particle separator assembly of the present invention;





FIG. 29

illustrates a perspective view of another embodiment of the particle separator of the present invention;





FIG. 30

illustrates a longitudinal section of the embodiment shown in

FIG. 29

;





FIG. 31

illustrates a top section view of the embodiment shown in

FIG. 30

;





FIG. 32

illustrates the projected collection efficiency based on CFD modeling of the cyclone system as illustrated in

FIGS. 1 and 16

;





FIG. 33

illustrates a plot of particle diameter vs. V


rp


for a range of inlet velocities for the alternative embodiment described in EXAMPLE 2











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




The present invention is a cyclone particle separation system that separates particles trapped in a gas stream and concentrates the particles in a liquid reservoir for analyzing. The particle separator is a lightweight, compact system that collects and concentrates biological material from the air. The system is used in conjunction with a control unit and can be integrated with several types of biodetectors and sensors or can be used as a stand-along system. The control unit (not shown) operates the cyclone assembly by controlling the flow rate and direction of air and liquid through the blower and peristaltic pump, respectively.





FIG. 1

illustrates the first embodiment of the present invention.

FIG. 1

describes a mini-cyclone particle separator and collector assembly


2


including a housing comprised of six, sections. The housing is comprised of six individual sections; however, the housing may be integral or constructed in any number of pieces as required. All housing sections are shown as generally cylindrical in overall shape, although other exterior shapes may be used. When assembled, each section is coaxial with respect to the assembly longitudinal central axis


6


and are held together by elongate bolts


4


extending the entire length of assembly


2


. The housing sections are made from plastic using an injection molding process; however, other materials and processes may be used.




As shown in

FIGS. 1 and 2

, the mini-cyclone particle separator assembly


2


includes base section


10


comprising an internal reservoir


12


and a lower vacuum chambers


14


. Referring to

FIGS. 1

,


2


and


3


B, lower vacuum chambers


14


is located toward the top of base section


10


adjacent underfluid or flow pipe outlet


28


of conical cyclone section


20


discussed below. Lower vacuum chambers


14


is connected in fluid or flow communication to four vacuum transfer channels


52


at lower openings


19


. Each opening


19


is located adjacent to underfluid or flow pipes


28


. Reservoir


12


stores the liquid and provides a collection location to receive liquid from underfluid or flow pipe


28


. At the bottom of the base section


10


, a small diameter central outlet


16


is provided to connect to the suction side of a peristaltic pump (not shown). The pump, in operation with a solenoid valve, lifts the liquid from internal reservoir


12


upwardly through a central liquid passage


24


of cyclone section


20


and into the top of the cyclone chambers


22


. Base section


10


may include an internal shoulder


18


located approximately midway down the height of interior wall of base section


10


. Internal shoulder


18


provides support for three screens (not shown) that break up any foam in the liquid stream fluid or flowing out of underfluid or flow pipe


28


. The control unit (not shown) can direct the liquid collected through a conduit attached to outlet


16


to a monitoring system to check for the presence of toxic microorganisms among the particles collected.




As shown in

FIG. 1

, the lower end of conical cyclone section


20


attaches to the top of base section


10


. Section


20


includes an internal flange or shelf


29


that extends from the central axis


6


and approaches the outer edge, leaving approximately the wall thickness of base section


20


. Referring to FIGS.


1


and


5


-


7


D, conical cyclone section


20


defines four separate particle separation or cyclone chambers


22


, each formed on a downwardly tapered, conical shape extending longitudinally therethrough. Each chambers


22


extends parallel to center axis


6


and is preferably disposed equidistant around central axis


6


. The conical cyclone section


20


includes a central, small diameter liquid passage pipe or conduit


24


that extends the entire length of conical cyclone section


20


. Liquid passage pipe


24


begins at the top of the conical cyclone section


20


and continues down the center of section


20


, along central axis


6


and then angles radially outwardly to connect to an outer passage


13


extending down through base section


10


. The bottom outlet


15


of outer passage


13


is connected to the pressure side of a miniature peristaltic pump (not shown) at the lower end of base section


10


. Liquid passage pipe


24


supplies liquid to top portion


23


of the conical chambers


22


through tangential inlet opening


26


. The liquid entering each chambers


22


through a tangential opening


26


traps the particles within the liquid as the liquid washes down the interior walls of chambers


22


. The liquid exits out of bottom portion


21


of chambers


22


through underflow pipe or apex outlet


28


and back into base section


10


. Underflow pipe


28


is connected to chambers


22


through screw threads


27


. The pump (not shown) supplies liquid to the chambers


22


through pipe


24


at a fluid or flow rate of about 1-25 milliliters per minute; however, greater or lesser fluid or flow rates can be achieved based on specific requirements of the user.




As shown in

FIG. 1

, cylindrical cyclone section


30


attaches to the top of conical cyclone section


20


. Referring to FIGS.


8


B and


9


A-


9


B, cylindrical cyclone section


30


includes four cylindrical cyclone chambers


30


. Each chambers


30


is aligned directly above a corresponding conical chambers


22


. Vacuum transfer channels


52


and clearance holes


66


extend through cylindrical cyclone section


30


.




As shown in

FIG. 1

, the bottom of cyclone inlet section


40


is attached to the top of cylindrical cyclone section


30


. Referring to FIGS.


8


A and


10


A-


10


C, cyclone inlet section


40


includes four chambers


42


each having inner wall or surface


44


. Each chambers


42


has a tangential inlet


43


that connects chambers


42


to the external environment. Chambers


42


further connects in fluid or flow communication with a corresponding cylindrical chambers


30


and a corresponding conical chambers


22


to form the entire cyclone chambers. Each inlet


43


has a generally rectangular shape in cross-section and connects to chambers


42


through entrance wall


46


. Entrance wall


46


is tangential to cylindrical inner surface


44


of chambers


42


. Each inlet


43


also is formed by a tapered entrance wall


48


to facilitate particle-laden gases to enter through inlet


43


to chambers


42


. Tapered wall


48


projects away from inner tangential wall


46


of the cylindrical chambers


42


by approximately 35 degrees. An air fluid or flow rate of about 100-500 liters per minute is achieved by the configuration of the present invention; however, greater or lesser fluid or flow rates may be achieved when additional cyclone chambers are used and/or when cyclone size is adjusted. To achieve the 100-500 liters per minute fluid or flow rate, in one preferred embodiment of the present invention, the assembly is preferably approximately 7 cm in diameter and approximately 20 cm in length employing four cyclone chambers. Preferably, the top of the cyclone chambers has a diameter of 2 cm, the bottom diameter of the bottom of the cyclone chambers is 0.6 cm, and the height of the cyclone chambers is 10 cm.




As shown in

FIG. 1

, upper cyclone vent section


50


is attached to the top of cyclone inlet section


40


by bolts extending through close fitting clearance holes


66


. Referring to FIGS.


11


and


12


A-


12


D, cyclone vent section


50


includes four vent passageways


54


that extend vertically through the generally disk-shaped vent section


50


. Each vent passageway is disposed parallel to assembly axis


6


directly above chambers


42


and has a threaded inner surface


55


. Four overflow pipes or vortex finder outlets


56


, cylindrical in shape, have partial threaded outside surfaces


57


. Each pipe


56


is attached to vents


54


by the meshing of corresponding threaded surfaces


55


and


57


. Overflow pipes


56


extend downwardly and into the respective cylindrical chambers


42


of cyclone inlet section


40


. Each overfluid or flow pipe extends from the bottom of upper cyclone vent section


50


to approximately the bottom of cyclone inlet section


40


.




Most of the incoming particle-laden gas moves downward in an helical fluid or flow pattern through the cyclone chambers (cylindrical and conical section). Some of the downward fluid or flow leaves through the underfluid or flow outlet through vacuum transfer passages


52


and exits out of upper vacuum chambers


62


. The rest of the gas (after most the particles have been separated and captured by the liquid) reverses its vertical direction and travels upwardly via an inner helical fluid or flow and exits the conical chambers through overflow pipe


56


. This gas continues up through vents


54


and out of the assembly by the blower induced vacuum.




As shown in

FIG. 1

, top section


60


is attached to the top of upper cyclone vent section


50


. Referring to FIGS.


13


and


14


A-


14


B, top section


60


includes an upper vacuum chambers


62


and an external coupling nipple


68


. External coupling nipple


68


is attached to a blower or vacuum pump (not shown). Top section


60


has four clearance holes


66


that extend the entire length of assembly


2


. Each vacuum transfer passage


52


exits into upper vacuum chambers


62


at an upper opening


64


. Upper vacuum chambers


62


is connected in fluid or flow communication with the top of conical chambers


22


through vents


54


and cylindrical chambers


30


.




In operation, a blower or vacuum pump draws outside gas into the cyclone particle separator assembly through radial inlets


43


. Vacuum transfer channels


52


, extending the entire length of the assembly


2


, pull gas into the top portion


23


of the cyclone chambers


22


and out through apex


28


of cyclone chambers


22


. Gas entering the cyclone particle separation chambers


22


from inlet


43


swirls downwardly through cylindrical cyclone section


30


and into the conical shaped chambers


22


due to the tangentially aligned inlet


43


. The gas travels in a helical pattern downwardly toward the bottom portion


21


of conical chambers


22


. Due to centrifugal forces, the particles flow outwardly away from the center axis of the chambers


22


and toward the walls of the respective chambers


22


. Liquid is pumped into chambers


22


from internal reservoir


12


through the central liquid passage tube


24


. This liquid wets the particles in chambers


22


and washes down the chambers walls flushing the particles into reservoir


12


. The liquid is continuously recirculated through the conical chambers by the peristaltic pump (not shown) thereby concentrating the particles within the liquid over time. The liquid then can be pumped to an optionally integrated detector/sensor system comprised of detectors and sensors. The detector/sensor system can send out a warning if toxic microorganisms are present. If particle concentration is not needed, the liquid can be pumped immediately to the detector/sensor system.




EXAMPLE 1




A scaled-down 20 LPM cyclone system according to one embodiment of the present invention was used in these initial tests using an aerosolized microorganism in an environmental chamber. An antigen-antibody test called “Origin” was used to quantify the microorganism collected by the cyclone system and growth of the organisms on culture medium. Initial results were obtained from the Origin assays for


Erwinia herbicola


tests. The Origin test recognized both living and killed biological material. The results (Table 1) indicate that the mini cyclone biocollector of the present invention is more efficient than the reference collector used.












TABLE 1











Collection Efficiency for


Erwinia herbicola


during a 15 minute






Sampling Period for Cyclones Biocollectors Compared to






All-Glass Impinger Reference Collector. Data are in






Colony-Forming Units per ml Collection Solution per






Liter Air Sampled. Organisms were quantified using the “Origin”






Antigen-Antibody Test.













Cyclone 1




Cyclone 2




Reference Collector









1.51 E3 




1.23 E3




1.05 E3






1.8 E3




1.93 E3




1.25 E3






2.7 E3




1.51 E3




1.11 E3















FIGS. 16-28

shows an alternative embodiment of the present invention. Referring initially to FIGS.


16


and


27


A-


27


C, the alternative embodiment is a particle separation assembly or system that uses cyclonic forces to separate and remove large particles from an airstream and concentrate small particles for sensor/detector technology. The alternative embodiment is a portable, multi-functional device that is suitable for pathogen separation and collection in field situations.




The alternative embodiment of the particle separator and collector assembly, as show in

FIGS. 27-28

, uses an outer cyclone to remove larger particles from an airstream and an inner mini-cyclone series to concentrates smaller particles into a liquid.

FIGS. 15-28

describes a mini-cyclone particle separator and collector assembly


102


includes a housing comprised of five sections. However, the housing may be integral or constructed in any number of pieces as required. All housing sections are cylindrical in shape, although other exterior shapes may be used. When assembled, each section is coaxial with respect to the assembly longitudinal central axis


106


and are held together by elongate bolts


104


extending the entire length of assembly


102


. The housing sections are made from plastic using an injection molding process; however, other materials and processes may be used.




As shown in

FIG. 16

, the. mini-cyclone particle separator assembly


102


includes fluid reservoir section


110


comprising a fluid chambers or reservoir


111


. Reservoir


111


stores the liquid and provides a collection location to receive liquid from underfluid or flow pipe


28


. Fluid reservoir


111


is divided into an upper cylindrical section


112


and a lower conical section


113


. Conical section


113


begins approximately midway down the internal surface of fluid reservoir section


110


and terminates at small diameter central outlet


114


at the bottom of fluid reservoir section


110


. Small diameter outlet


114


connects to the suction side of a peristaltic pump (not shown). The miniature peristaltic pump feeds each cyclone chambers


132


a metered volume of liquid through a tangential opening in the cyclone wall. Pumping rates as low as 0.25 ml/min to each cyclone have proved to be satisfactory for wet-wall operation. An electrical solenoid valve is used to direct fluid or flow up the central liquid passage


134


from reservoir


113


to the cyclone chambers


132


for recycling of liquid during a collection period (and thus concentration of particles), or alternatively out to a sample port or sensor/detector device for detection of any toxic microorganisms present in the liquid. When real time sensors for specific biological materials are developed a low continuous or intermittent liquid fluid or flow will be supplied to the cyclones that will then be pumped to the sensor unit.




The design has integrated fluid or flow channels for air and liquid movement. Several different reservoir sections


110


can be fabricated to hold varying amounts of liquid for wetting the walls of the cyclone chambers


132


and concentrating the sample. The layered component design of the cyclone assembly allows the operator to change reservoir components depending on the length of the sampling period desired. A larger reservoir is used for longer sampling periods so that enough liquid is available to replace evaporative loss.




Referring to

FIGS. 17-26

, a vertical column


116


is attached to the exterior surface of fluid reservoir section


110


and includes an internal channel


117


and a liquid collection and return conduit


118


. Internal collection and return conduit


118


is connected in fluid or flow communication to the pump (not shown) at the bottom of fluid reservoir section


110


. Internal channel


117


allows wires from both the pump and the blower to run the entire length of vertical column


116


. Vertical column


116


extends from the bottom of fluid reservoir section


110


up to the external surface of cyclone head section


140


. Liquid may be added to, the reservoir


111


by using the fluid collection port


139


. A collection tube filled with liquid is attached to fluid collection port


139


. Liquid from the collection tube is pumped through internal collection and return conduit


118


to the reservoir


111


by operating the pump in reverse mode. A secondary injection port


115


may also be included to fluid reservoir section


110


to allow liquid to be added to the reservoir. Secondary injection port


115


is located just below the top of fluid reservoir section


110


and can be used to inject liquid into the system using a syringe without powering up the pump (not shown).




As shown in

FIG. 16

, the lower end of splash guard section


120


attaches to the upper end of fluid reservoir section


110


and comprises a lower vacuum chambers


122


. Referring to

FIGS. 16 and 18

, lower vacuum chambers


122


is located adjacent to underflow pipe outlet


138


of conical cyclone section


130


discussed below. Lower vacuum chambers


122


is connected in fluid or flow communication to four vacuum transfer channels


146


at lower openings


124


. Vacuum transfer channels


146


extend from splash section


120


and terminate at top section


150


at opening


154


. Each lower opening


124


is located adjacent to underfluid or flow pipe


138


. Lower vacuum chambers


122


contains an upper cylindrical portion


127


and a lower conical portion


128


. Lower conical portion


128


terminates into outlet


129


. Outlet


129


allows liquid to return to reservoir


111


.




As shown in

FIG. 16

, the lower end of conical cyclone section


130


attaches to the top of splash guard section


120


. Cyclone section


130


includes an internal flange or shelf


131


that extends from the central axis


6


and approaches the outer edge, leaving approximately the wall thickness of splash guard section


130


. Referring to

FIGS. 16

,


19


,


20


and


25


, conical cyclone section


130


defines four separate chambers


132


, each formed on a downwardly tapered, conical shape extending longitudinally therethrough. Each chambers


132


is parallel to center axis


6


and is disposed equidistant around central axis


106


. The conical cyclone section


130


includes a central, small diameter liquid passage pipe or conduit


134


that extends within conical cyclone section


130


. Central liquid passage


134


begins at the top of the conical cyclone section


130


and continues down the center of section


130


, along central axis


106


and then angles radially outwardly to connect to an outer passage


125


extending down through splash guard section


120


and fluid reservoir section


110


and terminating at bottom outlet


115


. Bottom outlet


115


of outer passage is connected to the pressure side of a miniature peristaltic pump (not shown) at the lower end of fluid reservoir section


110


. Central liquid passage pipe


134


supplies liquid to the cylindrical chambers


142


through a tangential inlet openings


175


. The liquid entering each chambers


142


through the tangential opening traps the particles within the liquid as the liquid washes down the interior walls of chambers


132


. The liquid exits out of bottom portion


135


of chambers


132


through underfluid or flow pipe or apex outlet


138


and back into fluid reservoir section


110


. Underflow pipe


138


is connected to chambers


132


through screw threads (not shown), The pump (not shown) supplies liquid to the chambers


132


through pipe


134


at a fluid or flow rate of about 1-25 milliliters per minute.




Alternatively, as shown in

FIG. 22

, tangential openings


195


are rectangular in shape and extend up toward the top of conical cyclone chamber


142


.




As shown in

FIG. 25

, vertical column


116


attaches to the external surface of cyclone section


130


and includes a fluid collection and injection port


139


. Fluid collection port


139


is located on vertical column


116


approximately midway down the external surface of cyclone section


130


. A collection container may be attached to fluid collection and injection port


139


to collect the concentrated particle liquid from the reservoir or may be used to inject new liquid into the reservoir


111


.




As shown in

FIGS. 16

,


21


and


22


, cyclone head section


140


attaches to the top of cyclone section


130


. The cyclone head section


140


includes four cylindrical cyclone chambers


142


. Each chambers


142


is aligned directly above a corresponding conical chambers


132


. Cyclone head section


140


contains four inlets


143


that connects chambers


142


to the external environment. Chambers


142


further connects in fluid or flow communication with a corresponding cyclone chambers


132


to form the entire particle separation or cyclone chambers. Each inlet


143


has a generally rectangular shape in cross-section and connects to chambers


142


through an entrance wall (not shown). The entrance wall is tangential to the cylindrical inner surface of chambers


142


. Each inlet


143


is also formed by a tapered entrance wall (not shown) to facilitate particle-laden gases to enter through inlet


143


to cylindrical chambers


142


. The tapered wall projects away from the inner tangential wall of the cylindrical chambers


142


by approximately 35 degrees.




As shown in

FIG. 21

, four vent passageways


144


pass vertically through cyclone head section


140


. Each vent passageway is disposed parallel to assembly axis


6


directly above chambers


142


and has a threaded inner surface (not shown). Four overfluid or flow pipes or vortex finder outlets


147


, cylindrical in shape, have partial threaded outside surfaces (not shown). Each pipe


147


is attached to vents


144


by the meshing of the corresponding threaded surfaces. Overfluid or flow pipes


147


extend downwardly and into the respective cylindrical chambers


142


of cyclone head section


140


. Each overfluid or flow pipe extends from the bottom of top section


150


to approximately the bottom of cyclone head section


140


.




As shown in

FIGS. 27A-27C

, an outer cyclone separator


148


may attach to cyclone head section


140


. Outer cyclone separator or chambers


148


is arranged concentrically about central axis


106


. Referring to

FIGS. 27A-27C

(these FIGURES show an example of eight inner cyclone chambers instead of the four discussed previously), particle-laden gas enters outer cyclone vent


149


and into outer cyclone separator


148


and moves the gas in a helical fluid or flow. The helical structure of the outer cyclone separator


148


results in large particles (in this case >50 μm) being deposited on the inner surface of the outer cyclone, while air containing small particles is processed by the inner cyclones. The linear fluid or flow rate of 8 m/sec is diverted through outer cyclone inlet


149


to the inner cylinder at points corresponding to the eight inlets


143


of the inner cyclones chambers


132


around the circumference of the inner cylinder. Still referring to

FIGS. 27A-27C

, when outer cyclone separator


148


is desired, assembly


102


is modified so that vertical column


116


is not used. Liquid may be pumped to an exterior monitoring system (not shown) for analysis.




A catch bin (not shown) at the base of the outer cyclone separator


148


retains large particles as they fall to the bottom of the separator


148


. If necessary, a set of short helical fins (not shown) can be attached to the outer wall whose purpose will be to cause particles near the outer wall to fluid or flow toward the bottom. Heavier inorganic particles that are not of interest in the collection of biological organisms that have densities larger than 1.0 gm will move to the outer wall of the outer helix and be discarded with the larger particles. Cleaning outer cyclone separator


148


is accomplished by closing the inlets


143


, opening vents (not shown) in the catch basin and reversing fluid or flow of the blower unit to blow the large particles through the vents in the bottom of the catch basin.




Most of the incoming particle filled gas that enters cylindrical chambers


142


moves downward in an helical fluid or flow pattern through the cyclone chambers


132


. Some of the downward fluid or flow leaves through the underfluid or flow outlet


138


and into vacuum transfer passages


146


and then exits out of upper vacuum chambers


152


. The rest of the gas (after most of the particles have been separated and captured by the liquid) reverses its vertical direction and travels upwardly via an inner helical fluid or flow and exits the conical chambers through overflow pipe


147


. This gas continues up through vents


144


and out of the assembly by the blower induced vacuum.




As shown in

FIGS. 16 and 23

, top section


150


is attached to the top of cyclone head section


140


. Top section


150


includes an upper vacuum chambers


152


and an external coupling lip


156


. External coupling lip


156


is attached to a blower or vacuum pump (not shown). Top section


150


has four clearance holes


158


that extend the entire length of assembly


102


. Each vacuum transfer passage


146


exits into upper vacuum chambers


152


at an opening


154


. Upper vacuum chambers


152


is connected in fluid or flow communication with the top of cyclone chambers


132


through vents


144


and cylindrical chambers


142


.




In operation, a blower or vacuum pump draws outside gas into outer cyclone separator


148


. Larger particles are separated from smaller particles and collected in a catch basin. The smaller particles then enter the mini-cyclones in the cyclone particle separator assembly through radial inlets


143


. Vacuum transfer channels


146


, extending the entire length of the assembly


102


, pull gas into the top of the cyclone chambers


132


and out through lower apex


138


of cyclone chambers


132


. Gas entering the cyclone particle separation chambers


132


from inlet


143


swirls downwardly through cylindrical cyclone chambers


142


and into the conical shaped chambers


132


due to the tangentially aligned inlets


143


. The gas travels in a helical pattern downwardly toward the bottom


135


of conical chambers


132


. Due to centrifugal forces, the particles fluid or flow outwardly away from the center axis of the chambers


132


and toward the walls of the respective chambers


132


. Liquid is pumped into chambers


132


from liquid reservoir


111


through the central liquid passage tube


134


. This liquid wets the particles in chambers


132


and washes down the chambers walls flushing the particles into reservoir


12


. The liquid is continuously recirculated through the conical chambers by the peristaltic pump (not shown) thereby concentrating the particles within the liquid over time. The liquid then can be pumped to an optionally integrated monitoring system comprised of detectors and sensors. The monitoring system then can send out a warning if toxic microorganisms are present.




EXAMPLE 2




A prototype device was designed to achieve a high fluid or flow rate, high collection efficiency for 1-15 micrometer (μm) particles, rejection of particles >50 μm and a low power consumption/pressure drop. Design specifications for this example device were established to meet the following requirements although other specifications are possible for different design geometries as established using the calculations described later.




100% rejection of particles >50 gm




Total air fluid or flow rate >





800 l/min




Collection efficiency for 2 gin particles >50%




Overall System Design




The cyclone separator design consists of a two stage system of concentric components to remove large particles and retain small particles. As shown in

FIG. 27

, a single large outer cyclone is used to separate and reject particles >50 μm. An inner bank of multiple mini cyclones operating in parallel captures and concentrates small particles <20 μm. This unit has the capacity to process 1000 liters per minutes (LPM) air fluid or flow, transferring collected bioparticles to a liquid stream for concentration and/or analysis. The design of both inner and outer structures is based on calculations using formulae that mathematically describe particle movement under the influence of cyclonic and gravitational forces.




In order to process an air stream at 1000 LPM (1 m


3


/min.), we have formed a design for the inner cylinder housing the wet-walled multiple cyclone unit. The design accommodates eight mini wet-walled cyclones in a circular arrangement, each capable of a fluid or flow rate of 125 LPM. This will result in an inner unit with a diameter of 10 cm. Based on iterative calculations described below, a geometry yielding an inlet velocity of 8 m/sec has been selected to achieve the particle separating capability of the outer helical cavity (cyclone).




Inlet Fluid or Flow and Size Calculations




The geometry of the outer cyclone is determined on the basis of the total fluid or flow rate desired, i.e., 1000 LPM and the inlet velocity required to achieve the desired particle separation. For the design we have envisioned, large particles (>50 μm) must have a positive radial velocity so that they strike the inner wall of the outer cyclone. Small particles must have a negative radial velocity so that they will be captured by the inner bank of cyclones. The following calculations were used to determine the inlet velocity and inlet dimensions required.




The radial velocity of a particle at the wall of the 10 cm inner cylinder is calculated using the following formula:








V




r0




=−Q/A


  (1)






where




Q=volume fluid or flow rate in cm


3


/sec and




A=area of inner cylinder exposed to air fluid or flow.






Therefore;


V




r0




=−Q/A


=−16670/


πdh=−


130 cm/sec=−1.30 m/sec






where




d is the inner cylinder diameter (10 cm), and




h is the inlet height (4.1 cm.).




Assuming Stokes law for the particle drag coefficient, the radial velocity of a particle in this outer channel would be:








V




rp




=V




r0


+


t






v






U






2






/R


  (2)






where




U=inlet velocity (10 m/sec),




R=inner radius (0.05 in), and




t


V


=aerodynamic response time as defined by:








t




V


=


ρ






p






D






2




/18μ  (3)






where




ρ


p


=the particle density (1000 kg/m


3


, assuming a bioparticle with average density of 1.0),




D=the particle diameter in meters, and




μ=the viscosity of air (1.8×10


−5


).




Using equations 2 and 3, particle radial velocity can be calculated for particles of varying size at several inlet velocities (U).

FIG. 33

illustrates a plot of particle diameter vs. V


rp


for a range of inlet velocities. Negative values for V


rp


indicate movement toward the inner wall which will result in capture by the inner wet-wall cyclones. A positive value for V


rp


indicates movement toward the outer wall. In the 10 m/sec inlet fluid or flow example, particles larger than 12 μm flow to the outside of the structure and smaller particles flow to the inner walls where they are captured by the wet-walled cyclones. At a larger inlet fluid or flow rate, 12 m/sec, the particle size cut-off for capture by the wet-wall cyclones reduces to 10 μm. At a lower fluid or flow rate of 8 m/sec, particles smaller that 20 μm are captured. In all cases, larger particles move toward the outer wall and settle to the bottom of the structure for removal.




Therefore in order to establish a fluid or flow rate of 1000 LPM, the inlet will require a cross sectional area of 16.7 cm2.




Fluid or flow rate in m


3


/sec.=1.0 m


3


/min/60 sec./min.=0.0167 m


3


/sec.




Entry port area=0.0167 m


3


/sec/8 m/sec=0.0021 m


2


or (21 cm


2


)




For a square port, side dim.=(0.00167 m


2


) exp 0.5=0.0458 m or 4.58 cm.




Therefore, the inlet dimensions for the outer cyclone should be approximately 4.6×4.6 cm.




The same set of calculations are used to determine the inlet dimensions for the inner cylinder of cyclones in order to collect particles in the 1-20 μm size range.




In another embodiment of the present invention,

FIGS. 29-31

depict the cyclone chambers arranged linearly instead of arranged about a central axis. Nonetheless, the apparatus shown in these FIGURES functions in a manner analogous to the apparatus of the prior FIGURES, discussed above.




Air enters the system through the cyclone inlet ports (


180


) such that its velocity is tangential to the main cylindrical section (


181


). As it rotates, liquid is introduced from the liquid injection ports (


182


) to coat the inner surface of the cylinder and collect the particles that are thrown out by the cyclonic air currents. Approximately half the air reverses flow and then flows out through the vortex finder (


183


) that receives suction from the upper vacuum chamber (


189


). The other half, along with the liquid (which now contains the particles) flows out of the underflow opening (


184


) and into the upper portion of the lower vacuum chamber (


186


). The air then flows through the air return channel (


185


) to the upper vacuum chamber, where it merges with the air that came through the vortex finder and is sucked out via a blower attached to the blower opening (


187


). The liquid separates from the air and drips into the fluid reservoir which is the bottom portion of the lower vacuum chamber(


186


) carrying the particles with it to the liquid outflow tube (


188


). In a “once through” application, the liquid is then sent to a sensor/detector (not shown), and fresh liquid is pumped (pump not shown) into the liquid input port (


190


) and back to the fluid injection ports(


182


) via the liquid input tube (


191


). In a “batch” application, the liquid is recirculated from the fluid reservoir (


186


) by pumping through the input tube and distributed to each cyclone through the injection ports (


182


) and down into the cylindrical section where it continues to capture particles that impact the walls through cyclonic forces.




It should be apparent that four conical chambers were used for explanation purposes only and that any number of conical chambers may be used. It should also be apparent that the parts associated with the conical chambers (vacuum transfer channels, upper cyclone vents, cyclone inlets, underfluid or flow pipes, and overfluid or flow pipes) will change correspondingly with the number of conical chambers. Two cyclone geometries are primarily illustrated, one with four mini-cyclones in a radial geometry that samples 360 degrees and one with 12 mini-cyclones in a bipolar geometry as shown in

FIG. 29

, with inlets facing opposite each other. However, the present invention should not be limited to these numbers of cyclones or geometries. The redial design can have more cyclones, and the cyclones themselves may be larger or smaller, depending on the desired particle sizes to be collected. The same is true for the bipolar system, greater or fewer number of cyclones can be used and the cyclones may be larger or smaller in size. A uni-polar design is also possible, with inlets facing in one direction.




While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.



Claims
  • 1. A particle separator assembly for use with a blower and having a longitudinal assembly axis, the blower being connectable to the particle separator assembly and operable to draw a particle-laden gas stream through the particle separator assembly, the particle separator assembly comprising:a plurality of particle separation chambers, each of the particle separation chambers having an internal surface and operable to separate particles from the particle-laden gas stream supplied thereto; a vacuum chamber disposed in fluid flow communication with each of the particle separation chambers; an inlet for each particle separation chamber, the inlets directing particle-laden gas external from the assembly into the particle separation chambers and finally into the vacuum chamber; a liquid passage conduit connectable to a reservoir and in fluid flow communication with each particle separation chamber, the liquid passage conduit supplying a liquid from a reservoir to the internal surfaces of the particle separation chambers to wet such internal surfaces whereby the particles separated from the gas within each particle separation chamber collect on the wetted internal surfaces of the chambers and entrain within the supplied liquid; and an outlet for each particle separation chamber connected in fluid flow communication with the vacuum chamber for establishing fluid flow communication between the particle separation chambers and the vacuum chamber such that the particle separated gas and the particle entrained liquid exit the particle separation chamber outlets into the vacuum chamber.
  • 2. The assembly according to claim 1, wherein the plurality of particle separation chambers are disposed about the longitudinal axis of the assembly.
  • 3. The assembly according to claim 1, wherein the plurality of particle separation chambers is arranged in one or two rows about the lateral axis of the assembly.
  • 4. The apparatus according to claim 2, wherein the liquid passage conduit is disposed along the longitudinal axis of the assembly.
  • 5. The assembly according to claim 1, further comprising:a reservoir in fluid flow communication with each particle separation chamber and the liquid passage conduit.
  • 6. The apparatus according to claim 1, further comprising an outer cyclone chamber concentric to the longitudinal assembly axis, the outer cyclone chamber in fluid flow communication with the plurality of inlets.
  • 7. The apparatus according to claim 6, wherein the outer cyclone chamber further comprises an inlet, the outer cyclone chamber inlet enabling particle-laden gas external from the apparatus to enter the plurality of particle separation chambers through the plurality of inlets.
  • 8. A particle separator and collector assembly having a longitudinal axis, the assembly comprising:at least one particle separation chamber each formed with an internal surface and a longitudinal axis; a lower vacuum chamber disposed in fluid communication with the at least one particle separation chamber; at least one inlet in fluid communication with the at least one particle separation chamber, the at least one inlet enabling particle-laden gas external from the assembly to enter the at least one particle separation chamber; a liquid reservoir disposed in fluid communication with the lower vacuum chamber; and a liquid passage conduit interconnecting the liquid reservoir with the internal surface of the particle separation chamber to supply liquid from the reservoir to the internal surface of the particle separation chamber; wherein the particle-laden gas is drawn into the at least one inlet by a blower and channeled in a helical pattern through the conical-shaped particle separator chamber and into the lower vacuum chamber, the particles being forced outwardly away from the longitudinal axis of the particle separation chamber by centrifugal force as the gas is channeled through the conical-shaped particle separation chamber resulting, in the particles being separated from the gas and collected by the liquid being supplied to the internal surface.
  • 9. The assembly according to claim 8, further comprising an upper vacuum chamber disposed in fluid communication with the at least one particle separation chamber and at least one vacuum transfer channel, the at least one vacuum transfer channel interconnecting the upper vacuum chamber with the lower vacuum transfer channel.
  • 10. The assembly according to claim 8, wherein the inlet is disposed tangential to the particle separation chamber so that the gas entering the particle separation chamber begins to move in a helical pattern.
  • 11. An apparatus which separates particles from a gas stream and collects the particles within a liquid, the apparatus comprising:a housing defining a longitudinal axis, the housing comprising a top end portion connectable to a blower and a bottom end connectable to a pump; at least one cyclone chamber disposed within the housing and having an upper end and a lower end, the cyclone chamber having an outlet for exiting gas and liquid; at least one housing inlet in fluid communication with the cyclone chamber, the housing inlet enabling particle-laden gas external from the apparatus to enter the cyclone chamber; a liquid passage conduit disposed within the housing and connectable to a pump, the liquid passage conduit delivering the liquid to the upper end of the cyclone chamber; and a reservoir in fluid communication with a lower vacuum chamber, the cyclone chamber and the liquid passage conduit; wherein particle-laden gas is pulled through the cyclone chamber so that the particles are separated from the gas by centrifugal force and collected by the liquid supplied to the cyclone chamber, and wherein particle trapped liquid and particle separated gas exits the cyclone chamber through the cyclone chamber outlet.
  • 12. The apparatus according to claim 11, further comprising a plurality of cyclone chambers disposed within the housing.
  • 13. The apparatus according to claim 12, wherein the plurality of cyclone chambers are disposed equidistant around the longitudinal axis of the housing.
  • 14. The apparatus according to claim 12, wherein the plurality of cyclone chambers are disposed around the lateral axis of the housing in one or two rows.
  • 15. The apparatus according to claim 12, wherein the liquid passage conduit supplies the liquid to the plurality of cyclone chambers.
  • 16. The apparatus according to claim 15, wherein the liquid passage conduit is disposed along the longitudinal axis of the housing.
  • 17. The apparatus according to claim 11, the housing further comprising at least one vacuum transfer channel, the at least one vacuum transfer channel extends from the top end portion of the housing to the bottom end portion of the housing.
  • 18. The apparatus according to claim 17, the housing further comprising an upper vacuum chamber disposed in the top end portion of the housing, in fluid communication with a vortex finder in the upper portion of the cyclone chamber, the at least one vacuum transfer channel connecting the cyclone chamber outlet with the upper vacuum chamber so that the gas stream is pulled through the cyclone chamber.
  • 19. The apparatus according to claim 11, further comprising an outer cyclone chamber concentric to the longitudinal axis and coupled to the housing, the outer cyclone chamber in fluid communication with the housing inlet.
  • 20. The apparatus according to claim 19, wherein the outer cyclone chamber further comprises an inlet, the outer cyclone chamber inlet enabling particle-laden gas external from the apparatus to enter the at least one cyclone chamber through the housing inlet.
  • 21. A method for separating particles having an aerodynamic diameter greater than a specific cut size from a gas and entrapping the particles in a liquid using a particle separation assembly, the particle separation assembly having a plurality of cyclone separation chambers disposed longitudinally within a housing of the assembly and having an internal wall and defining a longitudinal axis, the housing including a top end connectable to a blower, a bottom end connectable to a pump, and housing inlets in communication with the cyclone separation chambers for external gas to enter the assembly, a liquid passage conduit connectable to the pump for delivering the liquid to the cyclone separation chambers, and a vacuum chamber in communication with the cyclone separation chambers, the method comprising:drawing a particle-laden gas into the inlets of the housing and through the plurality of cyclone separation chambers so that a the gas flows in a circular path conforming to the configuration of the chambers; separating particles greater than the cut size from the gas by the centrifugal force imposed on the particles from the circular flow path of the gas within the chambers to move the particles outwardly away from the longitudinal axis and toward the inner wall of each cyclone chamber; supplying each cyclone chamber with the liquid through the liquid passage conduit; entrapping the particles within the liquid and washing the particles down the inner walls of the cyclone chambers; and directing the particle entrapped liquid and the particle separated gas into the vacuum chamber.
  • 22. The method according to claim 21, wherein the particle separation assembly further having an outer cyclone chamber having an inlet coupled to the housing and in fluid communication with the housing inlets, the method for separating particles from a gas and collecting the particles within a liquid using a particle separation assembly further comprising the steps of:drawing a particle-laden gas into the inlet of the outer cyclone chamber; separating the larger particles from the particle-laden gas so that the smaller particles enter the housing inlets; and removing the larger particles from the housing.
  • 23. The method for separating particles from a gas and collecting the particles within a liquid using a particle separation assembly according to claim 21, further comprising the step of:removing the particle-laden liquid for analysis; and monitoring the particles collected from the cyclone separation chambers.
  • 24. An apparatus which separates particles from a gas and collects the particles within a liquid, the apparatus comprising:at least one particle separation chamber having an inlet for supplying particle laden gas external from the apparatus to the particle separation chamber, an outlet, and an internal surface, the particle separation chamber operable to separate particles entrained in the gas; a liquid passage conduit connected in fluid flow communication with the particle separation chamber, the liquid passage conduit connectable to a reservoir and operable to supply liquid from the reservoir to the internal surface of the particle separation chamber; and a vacuum chamber connected in fluid flow communication with the particle chamber outlet such that the particle separated gas and the particle entrained liquid exit the particle separation chamber outlet into the vacuum chamber.
  • 25. An apparatus which separates particles from a gas stream and collects the particles within a liquid, the apparatus comprising:at least one particle separation chamber having an inlet for supplying particle laden gas external from the apparatus to the particle separation chamber, an outlet for allowing the gas or liquid to exit the particle separation chamber, and an internal surface, the particle separation chamber operable to separate particles entrained in the gas; a reservoir for holding a liquid; a liquid passage conduit interconnecting the reservoir and the particle separation chamber in fluid flow communication, the liquid passage conduit operable to supply the liquid from the reservoir to the internal surface of the particle separation chamber; and a vacuum chamber connected in fluid flow communication with the particle chamber outlet and the reservoir, the vacuum chamber adapted to receive exiting particle separated gas and the particle entrained liquid from the particle separation chamber.
  • 26. An apparatus which separates particles from a gas stream and collects the particles within a liquid, the apparatus comprising:a housing defining a longitudinal axis, the housing comprising a top end portion connectable to a blower and a bottom end connectable to a pump; a plurality of cyclone chambers having a longitudinal axis substantially parallel to the housing longitudinal axis, the cyclone chambers disposed within the housing such that the longitudinal axis of the cyclone chambers are equidistant from the housing longitudinal axis; a housing inlet in fluid communication with each cyclone chamber, the housing inlets enabling particle-laden gas external from the apparatus to enter the cyclone chambers; and a liquid passage conduit disposed within the housing and connectable to a pump, the liquid passage conduit delivering the liquid to the cyclone chambers; wherein particle-laden gas is pulled through the cyclone chambers so that the particles are separated from the gas by centrifugal force and collected by the liquid supplied thereto.
RELATED APPLICATION

This application claims benefit from U.S. provisional application No. 60/139,495 filed Jun. 14, 1999, the disclosure of which is incorporated herein by reference.

US Referenced Citations (7)
Number Name Date Kind
2696275 Pring Dec 1954 A
3093468 Krochta Jun 1963 A
3727377 Chapman Apr 1973 A
4267048 Ohishi May 1981 A
4734109 Cox Mar 1988 A
5011517 Cage et al. Apr 1991 A
5238475 Keuschnigg Aug 1993 A
Provisional Applications (1)
Number Date Country
60/139495 Jun 1999 US