Abstract:
The present invention is directed to the separation of dust and debris from flowing fluid. Conventional cyclone separators and centrifugal separators present a tradeoff between the extent of dust separation and the cross-sectional area of fluid flow. Thus, increased flow capacity cannot be achieved without reducing the amount of dust removal. In contrast, the present invention allows for the increase of cross-sectional flow area without jeopardizing dust removal. The apparatus is designed such that the cross-sectional area of fluid flow can be increased independently of the radii of curvature of the redirections. Therefore, dust is still effectively removed while the flow capacity of the system is increased. Also included herein are embodiments utilizing these concepts of dust separation vacuum cleaner embodiments.

Description:
CROSS REFERENCE TO OTHER APPLICATIONS  
       [0001]    This application is filed as a continuation-in-part of co-pending application entitled “Axial Flow Centrifugal Dust Separator,” filed Dec. 12, 2002, which is a continuation-in-part of co-pending application Ser. No. 10/025,376 entitled “Toroidal Vortex Bagless Vacuum Cleaner Centrifugal Dust Separator,” filed Dec. 19, 2001, which is a continuation-in-part of co-pending application Ser. No. 09/835,084 entitled “Toroidal Vortex Bagless Vacuum Cleaner,” filed Apr. 13, 2001, which is a continuation-in-part of co-pending application Ser. No. 09/829,416 entitled “Toroidal and Compound Vortex Attractor,” filed Apr. 9, 2001, which is a continuation-in-part of co-pending application Ser. No. 09/728,602, filed Dec. 1, 2000, entitled “Lifting Platform,” which is a continuation-in-part of co-pending Ser. No. 09/316,318, filed May 21, 1999, entitled “Vortex Attractor.” 
     
    
     
       TECHNICAL FIELD OF THE INVENTION  
         [0002]    The present invention relates to the separation of dust and debris from fluid flow, and more specifically, to an improved dust separator that utilizes centripetal forces to separate fine particulates from a fluid stream. Also disclosed herein are embodiments utilizing dust separators of the present invention in vacuum cleaner applications.  
         BACKGROUND OF THE INVENTION  
         [0003]    Dust separation is achieved in the art by various means including filters, Lamella separators, deflection separators, cyclonic separators, etc. For instance, side and top plan views of typical cyclonic dust separator design  100  are depicted in FIGS. 1A and 1B, respectively. Here dusty air  101  enters tangentially at the top of cyclonic dust separator  100 . Dusty air  101  then spirals downward along conical wall  102 , indicated by flow lines  103 . While dusty air  101  spirals downward, dust particles  106  are ejected tangentially against conical wall  102 . The downward component of airflow  103  carries dust  106  downward. Once airflow  103  reaches the bottom of cyclonic dust separator  100 , airflow  103  is redirected upward. The curvature of airflow  103  prevents it from carrying dust  106  back upward. Ultimately, dust  106  is deposited at the bottom of conical dust separator  100 . Finally, cleaned air  104  exits via pipe  105 .  
           [0004]    [0004]FIGS. 2A and 2B depict a side plan view of cylindrical vortex dust separator  200  which is fully disclosed in parent application entitled “Axial Flow Centrifugal Dust Separator,” filed Dec. 12, 2002, which is hereby incorporated herein by reference. Specifically, FIG. 2B indicates cross-section A-A of FIG. 2A. Dusty air  201  is drawn in by centrifugal pump impeller  202 . Centrifugal pump impeller  202  spins air  201  at the rotational speed of centrifugal pump impeller  202  before propagating the air  201  outward. Airflow  203  then circulates downward along housing  204 . Inertia throws dust outward such that it circulates around the inner wall of housing  204 . Slot  206  is provided to allow dust  205  to enter collector box  207 . In order to prevent dust from returning into circulating airflow  203 , protective lip  210  is provided to prevent dust from exiting collector  207 . Since a higher pressure is developed inside collector box  207  than within housing  204 , cylindrical vortex airflow  203  is maintained without inhibiting heavier dust particles  206  from being expelled into collector box  207 . As a result, substantially cleaned air  208  exits through pipe  209 .  
           [0005]    [0005]FIG. 3 depicts typical circulating airflow  301  within a cyclonic or centrifugal dust separator. Dust particle  302  within flow  301  has mass “m”, tangential speed “V”, and trajectory radius of curvature “R”. The inward, or centripetal, force necessary to maintain circular flow  301  of particle  302  is given by mV 2 /R. A lesser force could not hold particle  302  within its circular path and therefore, particle  302  would outwardly exit circular flow  301 . Moreover, increasing the difference between mV 2 /R and the centripetal force (i.e., mV 2 /R-centripetal force) increases the rate at which dust particle  302  exits airflow  301 . Thus, by maximizing mV 2 /R, the amount of dust that can be ejected from flow  301  is also maximized.  
           [0006]    Unfortunately, when “R” is large (and thus, mV 2 /R is small), particle  302  travels slowly outward following spiral trajectory  401 , as seen in FIG. 4. Accordingly, the number of revolutions necessary to effectively remove dust particle  302  from flow  301  depends positively on “R”. However, both cyclonic separator  100  of FIG. 1 and centrifugal separator  200  of FIG. 2 provide a limited number of revolutions before air exits. In order to ensure adequate dust removal, the overall flowrate of the system must be kept sufficiently low to ensure that dust particles are precipitated out. Fortunately, the present invention provides an apparatus that can accommodate larger flowrates without compromising dust removal.  
           [0007]    In order to increase the overall flowrate while maintaining adequate dust removal in a cyclonic system, mV 2 /R must be increased. Since “m” is constant, either “V” must be increased or “R” must be decreased. In the case of cyclonic separator  100  of FIG. 1, “V” is the inherent speed of the airflow through the system, and thus, not easily increased. Any attempts at increasing “V” would result in higher power consumption. However, decreasing “R” reduces the cross-sectional area of the dust separator (i.e., area=nR 2 ) and consequently limits the overall flowrate through the dust separator.  
           [0008]    In the case of centrifugal separator  200  of FIG. 2, “V” can be increased, and also, the path length (i.e., the height of centrifugal separator  200  of FIG. 2) can be increased as described in parent application entitled “Axial Flow Centrifugal Dust Separator.” However, the goal of the present invention is to improve the performance of dust separators in which the airspeed is fixed by overall system requirements.  
           [0009]    Thus, there is a clear need for a method and apparatus that effects simple, inexpensive, and efficient removal of dust, debris, or any other matter in a system which the flowrate is fixed by overall system requirements. The art is devoid of references that teach effective removal dust and debris in such a system. However, to fully understand the present invention in its proper context, reference is made to the following U.S. Patents: Parkinson U.S. Pat. No. 499,799 (hereinafter referred to as “Parkinson”); Wingrove U.S. Pat. No. 768,415 (hereinafter referred to as “Wingrove”); Greer et al. U.S. Pat. No. 4,159,942 (hereinafter referred to as “Greer”); Gustavsson et al. U.S. Pat. No. 4,227,903 (hereinafter referred to as “Gustavsson”); Monson et al. U.S. Pat. No. 4,323,369 (hereinafter referred to as “Monson”); Krambrock et al. U.S. Pat. No. 4,528,092 (hereinafter referred to as “Krambrock”); Michel-Kim U.S. Pat. No. 4,541,845 (hereinafter referred to as “Michel-Kim”); Richerson U.S. Pat. Nos. 4,927,437 and 4,973,341 (hereinafter referred to as the “Richerson” patents); Lehrmann U.S. Pat. No. 5,181,617 (hereinafter referred to as “Lehrmann”); Bone et al. U.S. Pat. No. 5,966,774 (hereinafter referred to as “Bone”); and Sandell U.S. Pat. No. 6,066,211 (hereinafter referred to as “Sandell”).  
           [0010]    Parkinson discloses a dust separator that employs a series of S-shaped sheets around which air flows. When air passes through these sheets, a curved flow pattern that ejects dust is developed. The ejected dust then falls downward for removal. In contrast, the present invention operates independent of gravity, thereby functioning in any orientation.  
           [0011]    Wingrove discloses an apparatus for separating oil from a nitrogen gas stream. Here, gas must pass in a zigzagged pattern through a series of folded plates. At each turn, the gas expels oil against the plates. Gravity then drains the oil downward for removal. However, the present invention, which operates independent of gravity, can separate matter from fluids in any orientation. Furthermore, the present invention provides a smoother flow than found within the folded plates of Wingrove.  
           [0012]    Greer et al. discloses a device for separating particles in a fluid stream by size and/or density. Here the fluid stream is bent at 90° such that particulate matter is thrown outward. However, lighter particles are ejected slower than heavier particles. Thus, the ejection of lighter particles will occur further upstream than the ejection of heavier ones. Greer et al. provides a series of particle receptacles such that each receptacle will only capture particles within a certain size or density range. In contrast, the present invention provides means for preventing the separated matter from reentering fluid flow. Moreover, Greer et al. has some particulate flowing through the outlet. The instant invention, on the other hand, is capable of removing even fine particles from fluid flow.  
           [0013]    Gustavsson et al. discloses an apparatus for cleaning gases. Upon entering the system, a wall of deflection separators removes coarse particles from the system. This occurs by deflecting airflow upward while the heavier debris collides with the deflection guides. Subsequently, the debris falls downward. Fine particles are later separated by a filter. Ultimately, Gustavsson et al. teaches an apparatus capable of separating large particles by deflection. However, a more efficient device that is capable of removing fine particles without a filter is preferable.  
           [0014]    Monson et al. discloses an apparatus for cleaning particulate matter from air. Airflow originates from an annular duct. Then the airflow is redirected outward, and subsequently redirected inward. Upon the inward redirection, fluid partially exits through slits for removal while the remaining airflow continues onward. Because of the centrifugal effects of redirection, the outer part of airflow is dense in particulate matter. The particulate-dense fluid flow is then removed through the slits. It is preferable, however, to clean all fluid, and not eject a dirty stream of fluid. Thus, the instant invention can be configured to redirect fluid flow any number of times such that an arbitrarily large level of purity may be reached.  
           [0015]    Krambrock et al. discloses an apparatus for separation of debris from airflow. Upon entering the system, dirty airflow is sent into an upper, tapered section which disperses the debris evenly throughout airflow. Then, the airflow is sent downward through an annular duct. Once the dirty airflow reaches the bottom of the annular duct, a second airflow deflects the dirty airflow upward. However, the heavier debris is not deflected and continues downward for removal. Thus, cleaned airflow is sent upward where it exits the apparatus. Yet, a simpler system not requiring a second airflow for deflection is preferred.  
           [0016]    Michel-Kim discloses a separator utilizing a concentric nozzle design. The outermost annular duct formed within the concentric design provides dirty fluid. The flow is then redirected 180°, partially into an inner annular duct and partially into a central tubular duct. Thus, the fluid flow is split into two fractions after redirection. Because the particles are forced to the outside of the arcuate path during redirection, the fraction traveling through the central duct is dense in particulate matter. Conversely, the flow in the inner annular duct comprises substantially less particulate. It is preferable, however, to avoid the disposal of dirty fluid.  
           [0017]    The Richerson patents disclose centrifugal separator designs utilizing a spiraling pathway formed between two spiral-shaped sheets. As air flows through this spiral pathway, airborne particles are thrown against the walls of the spiraling structure. Under the force of gravity, the expelled particles then fall down into a collection trough. Preferably, as in the present invention, the separator does not rely upon gravitational forces such that the separator can be implemented in any orientation. Furthermore, the present invention provides simpler structural design, thereby easing manufacture.  
           [0018]    Lehrmann discloses a system for separating reclaimable material from a mixture. Therein, a pipe bent in a zig-zag configuration is used as a deflection sifter. A mixture of air and particulate material are sent upward through the sifter. The zig-zag configuration prevents larger particles from exiting the top outlet of the sifter. Consequently, they exit out of the bottom outlet of the sifter. The finer material, however, continues to travel with the airflow out of the top outlet of the sifter. Thus, the system is capable of separating fine material from heavier material. Yet, it is preferable to be able to separate both coarse and fine matter from the fluid flow.  
           [0019]    Bone et al. teaches a hand-held vacuum cleaner comprising a snout that opens to remove debris from the filter. As in a conventional design, air is sucked through a nozzle, an input duct, and a filter. Air is subsequently expelled from the system. However, filters are inefficient, and it is preferable to avoid their use entirely.  
           [0020]    Sandell discloses a vacuum cleaning system that draws air in through a nozzle, an elongated tube, a snout, a filter, and an impeller. Like other conventional portable vacuum cleaners, the Sandell system cleans air with a filter that is inefficient and prone to clogging.  
           [0021]    Thus, there is a clear need in the art for a bagless, filterless dust separator that can effectively handle large flowrates and is capable of separating fine dust particles. Furthermore, a need exists for such filterless, bagless separators to be implemented into vacuum cleaning systems or any application that benefits from efficient cleaning of fluid flow.  
         SUMMARY OF THE INVENTION  
         [0022]    This application is an extension of and improvement upon matter disclosed in co-pending application entitled “Axial Flow Centrifugal Dust Separator,” filed Dec. 12, 2002, which is hereby incorporated herein by reference. This application extends from and advances upon technology from Applicant&#39;s invention disclosed in co-pending application Ser. No. 10/025,376 entitled “Toroidal Vortex Bagless Vacuum Cleaner Centrifugal Dust Separator,” filed Dec. 19, 2001, which is hereby incorporated herein by reference. Furthermore, the separator of this application is an improvement extending from technology disclosed in co-pending application Ser. No. 09/835,084 entitled “Toroidal Vortex Bagless Vacuum Cleaner,” filed Apr. 13, 2001, which is hereby incorporated herein by reference. Additionally, the bagless vacuum cleaner of this invention is an advancement extending from technology disclosed in the co-pending application Ser. No. 09/829,416 entitled “Toroidal and Compound Vortex Attractor,” filed Apr. 9, 2001, which is hereby incorporated herein by reference. The attractors disclosed therein improve upon technology extending from matter disclosed in co-pending application Ser. No. 09/728,602 entitled “Lifting Platform,” filed on Dec. 1, 2000, which is hereby incorporated herein by reference. Finally, the lifting platform technology is an extension advancing over technology disclosed in co-pending application Ser. No. 09/316,318 entitled “Vortex Attractor,” filed May 21, 1999, which is hereby incorporated herein by reference.  
           [0023]    The present invention relates to dust separators that can handle large flow rates while maintaining a high degree of separation.  
           [0024]    A dust separator of the present invention is preferably of a rectangular form. Like cyclonic and cylindrical vortex dust separators, the present invention separates particulate matter centrifugally. However, the flowrate through separators of the present invention may be arbitrarily large without sacrificing efficiency.  
           [0025]    The layout of a separator of the present invention is preferably a rectangular parallelepiped. The flow through the separator generally follows a zigzagged pattern. Therefore, liquid will flow side to side (alternatively up and down, or in any other opposing directions) under the guidance of walls, partitions, or passages. Each time the fluid changes direction, dust and debris within the fluid flow are ejected by inertia. Therefore, fluid flow can be redirected an arbitrarily large number of times until the desired level of purity is obtained.  
           [0026]    However, as discussed supra, the radius of curvature at which the fluid is redirected must be minimized in order to maximize efficiency. Cyclonic and cylindrical separators necessarily lose cross-sectional area (ΠR 2 ) as radius of curvature R is decreased. On the other hand, the cross-sectional area of the present invention can be made arbitrarily large without increasing the radius of curvature. This is accomplished by increasing the width of the separator such that cross-sectional area is increased. The direction of the width increase is preferably orthogonal to the plane containing the vectors of overall flow direction and intermediate flow directions (i.e., the directions in which fluid flows between each redirection).  
           [0027]    In the area of redirection, inefficient eddies may form. To reduce such parasitic fluid flow, collectors may be provided to collect debris each time fluid is redirected. The pressure within these collectors is preferably higher than within the flowing fluid, thereby maintaining the path of redirected fluid without inhibiting dust particles from traveling into the collectors. To further reduce parasitic fluid flow, baffles may be placed within the collectors. Also, because the amount of particles in the dirty fluid flow decrease with each redirection, the widths of slots leading into the collectors may decrease after each redirection. Furthermore, the slots leading into the collectors may comprise lips to prevent separated matter from reentering fluid flow. Alternatively, the collectors may comprise electrostatically charged members to attract dust and debris.  
           [0028]    The present invention may also be implemented into vacuum cleaner embodiments, and more specifically disclosed herein, portable vacuum cleaners. The designs described infra intake fluid through a nozzle and a bendable rubber flap. Upon entry of fluid into the snout of the vacuum, fluid flow is redirected via “guide vanes,” such that dust and debris are centrifugally ejected into a collector. During the redirection, higher pressure is built-up within the collector than within the fluid flow. The resulting pressure differential helps maintain the curved path of redirected fluid flow without impeding the removal of dust and debris.  
           [0029]    Also, baffles may be provided within the collector in order to prevent mixing of fluid in the collector and the fluid flow. This reduces the formation of eddies and further increases the efficiency of the system.  
           [0030]    Once the dust and debris are removed, the fluid flows through a venturi and centrifugal pump before being expelled. As in the aforementioned separators related to the present invention, the flowrate capacity of the system may be increased without reducing its ability to separate dust and debris from the fluid flow. All other advantages of the separation system disclosed therein may also apply to the vacuum cleaners of the present invention.  
           [0031]    Thus, it is an object of the present invention to provide a separator that is capable of separating large debris from fluid.  
           [0032]    It is a further object of the present invention to provide a separator that is capable of separating fine debris, e.g., dust, from fluid.  
           [0033]    It is yet another object of the present invention to provide a separator which has a large cross-sectional area and a small radius of curvature for ejecting particles.  
           [0034]    Additionally, it is an object of the present invention to provide a collector for a separator that maintains fluid flow geometry via pressure differentials without jeopardizing dust and debris collection.  
           [0035]    Furthermore, it is an object of the present invention to provide a separator that minimizes parasitic fluid flow.  
           [0036]    Moreover, it is an object of the present invention to provide a separator capable of handling large flowrates.  
           [0037]    It is yet another object of the present invention to provide a vacuum cleaner system which fulfills any or all objects of the present invention.  
           [0038]    Thus, it is an object of the present invention to create a separator that may contain an arbitrary number of separation stages without substantially reconfiguring the device.  
           [0039]    These and other objects will become readily apparent to one skilled in the art upon review of the following description, figures, and claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0040]    A further understanding of the present invention can be obtained by reference to a preferred embodiment set forth in the illustrations of the accompanying drawings. Although the illustrated embodiment is merely exemplary of systems for carrying out the present invention, both the organization and method of operation of the invention, in general, together with further objectives and advantages thereof, may be more easily understood by reference to the drawings and the following description. The drawings are not intended to limit the scope of this invention, which is set forth with particularity in the claims as appended or as subsequently amended, but merely to clarify and exemplify the invention.  
         [0041]    For a more complete understanding of the present invention, reference is now made to the following drawings in which:  
         [0042]    [0042]FIG. 1A (FIG. 1A) (PRIOR ART) depicts a side plan view of a conventional cyclonic separator;  
         [0043]    [0043]FIG. 1B (FIG. 1B) (PRIOR ART) depicts a top plan view of a conventional cyclonic separator;  
         [0044]    [0044]FIG. 2A (FIG. 2A) (PRIOR ART) depicts a side plan view of a cylindrical vortex separator;  
         [0045]    [0045]FIG. 2B (FIG. 2B) (PRIOR ART) depicts a cross-section of the cylindrical vortex separator of FIG. 2A;  
         [0046]    [0046]FIG. 3 (FIG. 3) (PRIOR ART) depicts a typical flow path of the cyclonic and cylindrical vortex separators of FIGS. 1 and 2, respectively;  
         [0047]    [0047]FIG. 4 (FIG. 4) (PRIOR ART) depicts a possible flow path of dust within the cyclonic and cylindrical vortex separators of FIGS. 1 and 2, respectively;  
         [0048]    [0048]FIG. 5A (FIG. 5A) is a top plan view of an embodiment of the folded separator in accordance with the present invention;  
         [0049]    [0049]FIG. 5B (FIG. 5B) is a side plan view of an embodiment of the folded separator in accordance with the present invention;  
         [0050]    [0050]FIG. 6 (FIG. 6) is a plan view of an embodiment of the folded separator that illustrates parasitic fluid flow in accordance with the present invention;  
         [0051]    [0051]FIG. 7 (FIG. 7) is a plan view of the embodiment of the folded separator including collectors in accordance with the present invention;  
         [0052]    [0052]FIG. 8 (FIG. 8) is a plan view of a ripple flow separator in accordance with the present invention;  
         [0053]    [0053]FIG. 9A (FIG. 9A) (PRIOR ART) depicts a vertical cross-section of a conventional, portable vacuum cleaner;  
         [0054]    [0054]FIG. 9B (FIG. 9B) (PRIOR ART) depicts a horizontal cross-section of a conventional, portable vacuum cleaner;  
         [0055]    [0055]FIG. 10 (FIG. 10) depicts a vertical cross-section of a portable vacuum cleaner with a single stage dust separator in accordance with the present invention;  
         [0056]    [0056]FIG. 11 (FIG. 11) depicts a vertical cross-section of an alternate portable vacuum cleaner with a two-stage dust separator in accordance with the present invention;  
         [0057]    [0057]FIG. 12 (FIG. 12) depicts a vertical cross-section of another alternate portable vacuum cleaner with a two-stage dust separator in accordance with the present invention;  
         [0058]    [0058]FIG. 13 (FIG. 13) depicts a vertical cross-section of another alternate portable vacuum cleaner with a two-stage dust separator in accordance with the present invention;  
         [0059]    [0059]FIG. 14 (FIG. 14) depicts a vertical cross-section of the preferred portable vacuum cleaner with a three-stage in accordance with the preferred vacuum cleaner embodiment of the present invention; and  
         [0060]    [0060]FIG. 15 (FIG. 15) depicts the preferred ripple flow separator in accordance with the preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0061]    As required, detailed illustrative embodiments of the present invention are disclosed herein. However, techniques, systems, and operating structures in accordance with the present invention may be embodied in a wide variety of forms and modes, some of which may be quite different from those in the disclosed embodiments. Consequently, the specific structural and functional details disclosed herein are merely representative, yet in that regard, they are deemed to afford the best embodiments for purposes of disclosure and to provide a basis for the claims herein which define the scope of the present invention. The following presents a detailed description of a preferred embodiment (as well as some alternative embodiments) of the present invention and features thereof.  
         [0062]    Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words “in” and “out” will refer to directions toward and away from, respectively, the geometric center of the device and designated and/or reference parts thereof. The words “up” and “down” will indicate directions relative to the horizontal and as depicted in the various figures. The words “clockwise” and “counterclockwise” will indicate rotation relative to a standard “right-handed” coordinate system. Such terminology will include the words above specifically mentioned, derivatives thereof, and words of similar import.  
         [0063]    Generally, embodiments of the present invention are able to provide a large cross-sectional area without necessitating a large radius of curvature where particles are separated. Side plan and top plan views of separator  500  of the present invention are illustrated in FIGS. 5A and 5B, respectively. Note, however, the present invention can operate in any orientation independently from gravity. Consequently, the present invention does not have a true top or bottom. However, “top” and “side” are used only for exemplary purposes to aid in the understanding of the invention, and accordingly, do not limit the scope of the present invention. Here, dirty fluid  501  enters via inlet  502 . Subsequently, fluid flows around a series of partitions  503  such that fluid flow  504  reverses direction repeatedly. As shown, fluid flow  504  exhibits small radii of curvature each time fluid flow  504  reverses direction. Because of the high mass of dust particles, dust  505  is deposited in the spaces in between partitions  503 . In such a configuration, the cross-sectional area of fluid flow is defined by the product of spacing between partitions W multiplied by partition height H (i.e., area=W×H). Thus, the cross-sectional area can be increased by increasing H. Preferably, W is minimized such that the radii of curvature are also minimized. Consequently, large cross-sectional area can be achieved with small values of W, by making H sufficiently large. Hence, with a folded design, a single separator can be used to accommodate any flowrate. Consequently, accommodating larger flowrates with multiple separators in parallel is unnecessary. Further, the folded dust separator operates independent of gravity, and advantageously, functions in any orientation.  
         [0064]    In cyclonic and centrifugal separators, fine dust particles require many revolutions to be ejected. In contrast, the folded design of the present invention can be readily extended to have an arbitrarily large number of sections. Heavy dust and dirt particles are thrown out of the fluid stream within the earlier fluid flow redirections. Subsequent sections may be added for the removal of increasingly finer dust particles.  
         [0065]    In the folded separator of the present invention, eddies may form in the areas of redirection. These eddies may pick up dust and debris already removed from fluid flow. Furthermore, eddies may contribute to frictional losses within fluid flow. FIG. 6 shows where eddies  601  may form in the collection areas. Fluid flow  602  around the ends of partitions  603  induces vortex fluid flow (i.e., eddies  601 ) in the collecting areas. Eddies are generally found in dust separating systems that allow the dust collecting areas to remain open to the main fluid flow. Nevertheless, eddies can be eliminated by implementing baffles or separating the collecting area from the main fluid flow.  
         [0066]    [0066]FIG. 7 shows a plan view of section  700  of such a folded separator comprising a series of collectors  701  connected to turning fluid flow  702  by slots  703 . These slots  703  prevent dust and debris from reentering main fluid flow  702  from collectors  701 . As in collector  207  of FIG. 2, a higher pressure is developed within collectors  701  than in fluid flow  702 . This pressure differential maintains the turning path of fluid flow  702  without impeding dust and debris  704  from being expelled into collectors  701 . Also, circulating fluid flow  705  may develop within collectors  701 . To prevent this, collectors  701  may comprise baffles (not shown) to inhibit fluid circulation within collectors  701 . Because dust particles remaining in fluid flow  702  decrease in size after each redirection, the width of each subsequent slot  703  may also decrease in size. This minimizes energy losses from the mixing of fluid flow  702  with fluid in collectors  701 . Additionally, protective lips  706  may be provided for slots  703  such that dust and debris do not reenter fluid flow  702 .  
         [0067]    A complete dust separator of this embodiment of the present invention may comprise many sections  700  connected in a series. Separators in accordance with this embodiment of the present invention effectively separate fine dust particles from fluid flow. Like the embodiment disclosed in FIG. 5, an arbitrarily large cross-section may be provided by increasing the height of the partitions while maintaining a small radii of curvature.  
         [0068]    Ideally, the angle of curvature is 180°. Because of the geometry of multistage separators of the present invention, the angle of curvature is generally smaller (often between 120° and 130°). Preferably, folded dust separators of the present invention redirect fluid flow at angles approaching 180°. Further, radii of curvature are preferably between 0.1″ to 0.2″, although they may be smaller or larger if desired. However, the present invention is capable of maintaining smaller radii of curvature than cyclonic separators for any given flowrate. Consequently, under identical conditions, the folded dust separators of the present invention can more effectively separate particles from any magnitude of fluid flow than conventional dust separators can.  
         [0069]    The folded dust separator of FIG. 7 creates an elongated path through which fluid must travel. In certain circumstances, the distance which fluid must travel is preferably minimized. FIG. 8 illustrates ripple separator  800  of the present invention providing such a “minimized” distance. Advantageously, ripple separator  800  can be constructed smaller, to reduce flow resistance, and more efficiently deflect finer particles from the fluid stream. The name “ripple” is used because the shape of the resultant flow path. As in previous embodiments, ripple separator  800  is partitioned into multiple collectors  801  via partitions  802 . At the ends of partitions  802  are deflectors  803 . During operation, fluid flow  804  is guided by deflectors  803  through ripple separator  800 . Each time fluid flow  804  is redirected by deflectors  804 , dust and debris  805  are ejected against deflectors  804 . Subsequently, dust and debris  805  bounce off of deflectors  803  into collectors  801 . Ultimately, separated dust and debris  806  remain within collectors  801  as fluid flow continues throughout ripple separator  800 . Importantly, courser separated dust and debris  806  are removed into collectors  801  that are closer to the entrance (i.e., the left side). Finer separated dust and debris  806  are removed in collectors  801  further along the path of fluid flow  804  (i.e., to the right). Therefore, increasing the number of deflectors  803 , partitions  802 , and collectors  801  will increase the level of separation achieved by this system.  
         [0070]    While in use, dust and debris  805  may adhere, or clump, to deflectors  803  or partitions  802 . In the case that dust and debris  805  do not adhere or clump to partitions  802 , dust and debris  805  may bounce around within collectors  801  and possibly reenter fluid flow  804 . To prevent such occurrences, collectors  801  may be enlarged, or baffles (not shown) may be implemented to slow down fluid and dust movement within collectors  801 . The baffles may comprise one or more plates disposed within collectors  801 . Alternatively, electrostatically charged members may be disposed within collectors  801  to attract dust and debris  805 . Partitions  802  may also be electrostatically charged for attracting dust and debris  805 .  
         [0071]    Furthermore, the separators of the present invention are not only capable of separating dust from fluid flow. Larger matter such as dirt, sand, etc., can also be separated using the separators of the present invention. Additionally, separators of the present invention can separate matter from a variety of fluids, both liquids and gases.  
         [0072]    Additional modifications may be made to a ripple flow separator of the present invention to enhance dust and debris collection. FIG. 15 illustrates ripple separator  1500 , which is the preferred ripple separator of the present invention. As in previous embodiments, fluid flow  1501  is deflected by deflectors  1502 . During deflection, fluid flow ejects dust and debris into collectors  1503 .  
         [0073]    While in use, dust and debris may adhere, or clump, to deflectors  1502  or partitions  1504 . In the case that dust and debris do not adhere or clump to partitions  1504 , the dust and debris may bounce around within collectors  1503  and possibly reenter fluid flow  1501 . To prevent such occurrences, collectors  1503  may be enlarged, or baffles  1505  may be implemented to slow down fluid, dust, and debris movement within collectors  1503 . Alternatively, electrostatically charged members may be disposed within collectors  1503  to attract dust and debris. For instance, baffles  1505  or partitions  1504  may be electrostatically charged for attracting dust and debris.  
         [0074]    Moreover, to aid in the collection of dust and debris, deflectors  1502  may be curved in the upstream direction as shown in FIG. 15. This prevents escape of the dust and debris while guiding it into collectors  1503 .  
         [0075]    Up to this point, separators have been discussed which may be used for any number of applications without departing from the scope of the present invention. One such application is a portable vacuum cleaner. Horizontal and vertical cross-sections of a conventional portable vacuum cleaner are depicted in FIGS. 9A and 9B, respectively. Particularly, portable vacuum cleaner  900 , fitted with handle  912  and power switch  913 , utilizes motor  901  powered by batteries  902 . Motor  901  drives a centrifugal pump impeller  903  such that air is taken into nozzle  904  formed within removable snout  905 . Additionally, removable snout  905  acts as a debris collector by holding debris in dust collection area  906 . Within removable snout  905 , input duct  907  is constructed with rubber flap  908  at the proximal end. When motor  901  is running and air is being sucked into input duct  907 , rubber flap  908  bends toward centrifugal pump impeller  903  allowing air to flow through the system. When motor  901  is off, however, rubber flap  908  seals input duct  907  preventing debris from falling out of portable vacuum cleaner  900 .  
         [0076]    During use, air flows directly from input duct  907  and through filter  909 . As the dirty air flows through filter  909 , the debris is captured while cleaned air continues onward through air venturi  910 . After passing through centrifugal pump impeller  903 , air is ejected out air outlets  911 .  
         [0077]    When the power is turned off and vacuum cleaner  900  is held with nozzle  904  down, some of the captured dirt falls into dust collection area  906 . However, a considerable amount of dirt remains lodged in filter  909  which quickly becomes clogged. Furthermore, filters impede airflow requiring additional power to move air through the system. The present invention advances by sufficiently cleaning fluid flow without the use of a filter.  
         [0078]    [0078]FIG. 10 depicts a vertical cross-section of portable vacuum cleaner  1000  of the present invention. Here, nozzle  1001  and input duct  1002  are formed within snout  1003 . The proximal end of input duct  1002  is terminated with rubber flap  1004 . In order to permit inflow, rubber flap  1004  bends inward unblocking the proximal end of input duct  1002 . Projecting within snout  1003  are guide vanes  1005 . These guide vanes  1005  are used to properly direct fluid flow for removal of dust and debris. At the proximal end of snout  1003 , is venturi  1006  that leads into centrifugal impeller pump  1007 . Additionally, snout  1003  is shaped to comprise collector  1008  for storing separated dust and debris. Optionally, snout  1003  may be detachable such that dirt and debris can be easily removed.  
         [0079]    In operation, dirty fluid  1009  enters nozzle  1001  and flows through input duct  1002 . While the motor is in operation, rubber flap  1004  is sucked in such that dirty fluid  1009  may flow by it. Then, fluid flow is guided by guide vanes  1005  in curved path  1010 . While fluid flow follows curved path  1010 , dense dust and debris  1011  continue straight into collector  1008 . Thus, dust and debris are centrifugally removed from the fluid flow. Importantly, the pressure in collector  1008  is greater than the pressure along curved path  1010 . The resulting pressure differential pushes fluid flow into its curved path  1010  without preventing higher mass dust and debris  1011  from traveling straight into collector  1008 . Additionally, collector  1008  may comprises baffles (not shown) or to prevent mixing of fluid within collector  1008  and fluid flow  1010 . Furthermore, collector  1008  may comprise electrostatically charged members to attract dust and debris  1011 . This prevents the formation of parasitic eddies and improves overall efficiency. Subsequent to separation, fluid flow is directed through venturi  1006  and centrifugal pump impeller  1007 . Then the fluid may be ejected.  
         [0080]    Significantly, guide vanes  1005  and collector  1008  form a single stage of a folded dust separator. This single stage method more effectively separates dirt and debris than conventional vacuum cleaner bags and filters. Moreover, clogging of bags and filters is successfully avoided.  
         [0081]    By devising alternative guide vane arrangements, a multistage folded separator can be fitted into the vacuum cleaner snout. Portable vacuum cleaner  1100  of the present invention, shown in FIG. 11, illustrates a two-stage system. Dirty air  1102  enters detachable snout  1104  through nozzle  1101  into input duct  1103  and passes by rubber flap  1105  similarly to the embodiment of FIG. 10. Fluid flow is immediately redirected along curved path  1110  causing dust and debris  1106  to be thrown into the first collector  1107 . The fluid flow is then redirected a second time along curved path  1111  such that a second dust separation occurs and finer, remaining dust and debris  1108  exit into second collector  1109 . As in the embodiment of FIG. 11, cleaned fluid flow  1112  is smoothly guided to through centrifugal pump impeller  1114  via venturi  1113 . In both first collector  1107  and second collector  1109 , the pressure is higher than in curved paths  1110  and  1111 , respectively. As stated supra, the curved fluid flow is maintained by these higher pressures without inhibiting dust from carrying into first collector  1107  and second collector  1109 . First collector  1107  and second collector  1109  may also comprise baffles to maximize efficiency, as indicated for the embodiment of FIG. 10. Moreover, the embodiment of FIG. 11 may comprise any and all of the additional features indicated for the embodiment of FIG. 10.  
         [0082]    Alternatively, the separation process and the corresponding structure included within portable vacuum cleaners of the present invention may effect an arbitrary number of additional stages. Thus, any desired level of separation may be achieved by configuring guide vanes for additional stages of separation. As outlined supra, the throughput of the present invention can be increased without comprising the flow dynamics and efficiency of the system.  
         [0083]    Alternatively, portable vacuum cleaners of the present invention can be constructed as shown in FIGS. 12 and 13. FIG. 12 illustrates an alternative embodiment of a portable vacuum cleaner with a single collector. Portable vacuum cleaner  1200  comprises nozzle  1201 , snout  1202 , input duct  1203 , rubber flap  1204 , and centrifugal pump impeller  1210  similar to the embodiments of FIGS. 10 and 11. However, single guide vane  1205  is used to guide fluid flow  1206  through the system. Fluid flow  1206  is redirected into venturi  1207  by high pressure in collector  1208 . During redirection, dust and debris  1209  flow into collector  1208 . Baffles or electrostatically charged members (not shown) may be included within the dust box to prevent dust and debris  1209  from reentering fluid flow  1206 . Finally, cleaned fluid flow  1206  exits via centrifugal pump impeller  1210 .  
         [0084]    With reference to FIG. 13, portable vacuum cleaner  1300  comprises nozzle  1301 , snout  1302 , input duct  1303 , and centrifugal pump  1304  as described in previous embodiments. The system may also comprise a rubber flap (not shown). Fluid flow  1305  is directed through the system by guide vanes  1306 . Through pressure guided redirection, dust and debris  1307  are ejected into collectors  1308  and  1309 . Upon a first redirection along path  1315 , dust and debris  1307  are expelled into collector  1308 . During the second redirection along path  1316 , dust and debris  1307  are expelled into collector  1309 . Collectors  1308  and  1309  may be separated by a partition (not shown) or left open to each other as shown. With no such partition, all dust and debris  1307  is free to fall into collector  1308  when portable vacuum cleaner  1300  is turned off and hung nozzle down. Additionally, collectors  1308  and  1309  may contain baffles or electrostatically charged members (not shown). Finally, cleaned fluid flow  1306  is ejected from the system via venturi  1310  and centrifugal impeller pump  1304 . Also, snout  1302  may be constructed to be detachable.  
         [0085]    In the preferred vacuum cleaner of the present invention, portable vacuum cleaner  1400  of the present invention may be constructed with three sections as disclosed in FIG. 14. As disclosed in previous embodiments, portable dust separator  1400  comprises nozzle  1401 , snout  1402 , input duct  1403 , and centrifugal pump impeller  1404 . A rubber flap (not shown) may also be implemented. Guide vanes  1405  of this embodiment guide fluid flow  1406  into three separation steps utilizing collectors  1407 ,  1408 , and  1409 . High pressure within these collectors redirects fluid flow  1406  three times throughout the system such that dust and debris  1410  are ejected into collectors  1407 ,  1408 , and  1409 . Once again, collectors  1407 ,  1408 , and  1409  may comprise baffles or electrostatically charged members (not shown) to prevent dust or debris from reentering fluid flow  1406 . Cleaned fluid flow  1406  exits the system via venturi  1411  and centrifugal pump impeller  1404 . When the system is turned off and portable vacuum cleaner  1400  is held nozzle down, dust and debris  1410  will fall into collector  1407  without escaping from snout  1402 . Further, snout  1402  can be made to be detachable.  
         [0086]    In the embodiments disclosed herein, guide vanes are often attached to the body of the dust-buster (i.e., not the snout) so that when the snout is removed the dust and debris can be easily poured out. Alternatively, the guide vanes may be attached to the snout, or even removably attached to the snout. Thus, the body, guide vanes, and snout may be detached from one another in any combination for ease of cleaning and maintenance. Also, the portable vacuum cleaners of the present invention may also comprise, but are not limited to, a handle, batteries, a motor (which may be battery powered), a combustion engine, a light, an on/off switch, power adjustment means, and various other features without departing from the spirit of the present invention.  
         [0087]    While the present invention has been described with reference to one or more preferred embodiments, which embodiments have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, such embodiments are merely exemplary and are not intended to be limiting or represent an exhaustive enumeration of all aspects of the invention. The scope of the invention, therefore, shall be defined solely by the following claims. Further, it will be apparent to those of skill in the art that numerous changes may be made in such details without departing from the spirit and the principles of the invention.