Abstract:
Methods and apparatus are disclosed that pick up and clean landscape rock using air under vacuum pressure. This apparatus provides a means for cleaning and reusing rock that has become aesthetically unattractive instead of removing the old landscape rock and replacing it with new rock. The invention also includes a device for separating debris from the vacuum airstream. This device may be used in combination with the device for picking up and cleaning landscape rock or may be used independently.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is directed to an apparatus and method for vacuuming up landscape rock and debris and more particularly to an apparatus and method for separating the landscape rock from the debris and thereby cleaning the landscape rock. 
         [0003]    2. Description of Related Art 
         [0004]    There are many forms of decorative ground cover including mulch and decorative rock. Most forms of decorative ground cover deteriorate over time. Mulch decays, fades, and gets carried away by wind, water, animal foraging, and foot traffic. It frequently requires annual replenishment. Decorative rock is stable and lasts for years, but it is also prone to losing its aesthetic qualities. Silt, soil or both washes into the decorative rock from the adjacent ground and from downspout runoff. Decomposed leaves, seeds, sticks, grass trimmings, etc. eventually fill in the decorative ground cover. Over time weeds proliferate because of the accumulation of dirt. In arid areas the buildup of airborne sand is a problem. If located near roadways, there can be a problem with sand from snow removal. 
         [0005]    Home owners have struggled to clean their landscape rock in a variety of ways including picking it up manually and cascading it over an improvised screening device while simultaneously hosing it off. Such methods are cumbersome, tedious and involve handling the rock multiple times. 
         [0006]    Commercial grounds keepers generally opt to just replace the rock, bringing in front-end loaders and other heavy equipment. This is expensive and prone to causing damage to existing lawns and shrubbery. Equipment is currently available for picking up landscape rock by means of a vacuum. Examples of such vacuum systems include U.S. Pat. No. 4,723,971 entitled “Industrial Vacuum Cleaner” issued on Feb. 9, 1988 to Ladislan B. Caldas, U.S. Pat. No. 4,735,639 entitled “Modular Industrial Vacuum Loading Apparatus for Ingesting and Collecting Debris and Filtering Discharged Air” issued on Apr. 5, 1988 to Duncan Johnstone, the teachings of which are incorporated herein by reference in their entirety, as well as the industrial vacuum sold by Christianson Systems, Inc. of Blomkest, Minnesota under the tradename “RockVac.” But, such vacuums do not clean the rock so it can be reused. The old rock, along with accompanying dirt and debris, is often disposed of in landfills, thereby exacerbating a growing ecological problem. 
         [0007]    Accordingly, there is a need for an apparatus for cleaning landscape rock that can be made portable for on-site use, that is reliable, that is relatively easy to operate, that is capable of handling rock and debris that is accompanied by broad range of moisture contents, and that does not discharge an appreciable amount of dust to the environment. 
       SUMMARY 
       [0008]    The present invention is an apparatus that uses vacuum to pick up and clean landscape rock. The preferred embodiment consists of an intake means through which rock and debris are sucked into the apparatus, an entry section, a rock-debris separator chamber, a pre-exhaust, a means of collecting the cleaned rock for reuse, an air-debris separator cell, a means of collecting the debris for disposal or reuse, and a vacuum means consisting of a dust collector and a vacuum blower or pump. 
         [0009]    Immediately upon being picked up by vacuum through the intake head, the rocks collide with each other and with the walls of the intake hose where dirt adhering to the rocks is dislodged, thereby initiating the cleaning of the rock that takes place within the apparatus. The flow of air, rock and debris entering through the intake means passes into an entry section, which is a generally horizontal chamber. Within this entry section the rocks continue to collide with each other and with the walls of the entry section, thereby continuing the cleaning process that started within the intake hose. Additionally, the top of the entry section is made to slope downward toward the entry section outlet, thereby deflecting the flow downward as the air, rock and debris leave the entry section. 
         [0010]    Upon leaving the entry section, the flow enters a rock-debris separator chamber where the rocks continue to collide with one another and with the walls of the chamber and where the separation of the rock and debris takes place. Because of the larger dimensions of the chamber the velocity decreases substantially, thereby facilitating the separation by gravity of the rock from the debris. The bottom of the chamber slopes downward toward the discharge outlet through which the cleaned rocks are removed and collected in a collection means such as a removable 5-gallon pail or a hopper, from which the rock is periodically removed for reuse. The air and entrained debris is removed through the chamber exhaust outlet on the top of the chamber. 
         [0011]    Ambient air is pulled by vacuum into the discharge outlet or the collection means, where it flows upward through the discharge outlet into the chamber and out through the chamber exhaust along with the main flow of air entering through the intake means. The countercurrent flow of air and rock within the discharge outlet entrains the debris, but not the denser rock as it leaves the chamber. This upward airflow from the discharge outlet also assists in carrying the separated debris upward toward the chamber exhaust outlet. 
         [0012]    Another embodiment of the chamber design involves an auxiliary air supply directly to the chamber, entering on the side opposite the chamber inlet and works in conjunction with another embodiment, a flexible impaction shield. Both minimize the accumulation of damp debris on the chamber walls resulting from the direct, high velocity impact of air on the inner walls of the chamber. 
         [0013]    The chamber may also have an access means to allow personnel to inspect, repair and maintain the inside of the chamber. 
         [0014]    The velocity of the flow of air, rock and debris within the chamber is further reduced by another aspect of the preferred embodiment, the pre-exhaust. The pre-exhaust abruptly withdraws a portion of the entering air from the entry section, the inlet side of the chamber or from the top of the chamber with the aid of a partition located close to the inlet side of the chamber. If the partition is employed, it extends preferably from just above the top of the chamber inlet to the chamber exhaust outlet. The top portion of the partition is pivotally connected to the bottom portion of the partition so that it can be adjusted to alter the relative flow rates of air leaving through the pre-exhaust outlet and the chamber exhaust outlet. 
         [0015]    The air and debris exhausted from the pre-exhaust outlet and the chamber exhaust outlet flows vertically upward to the air-debris separator cell, or cell, located directly above the chamber. The cell is oriented horizontally and is substantially cylindrical or oval in configuration. The entering air undergoes a rapid decrease in velocity due to the much larger dimensions of the cell, thereby allowing the debris to separate from the air primarily by gravity settling. 
         [0016]    There are many possible configurations of cell inlets and outlets, but the preferred arrangement is for the flow to enter vertically in an upward direction in the cell bottom portion of the cell middle section. The location of the vertical cell inlet(s), as it penetrates the circumference of the cell, lies between radial and tangential, though closer to the latter is preferred. This configuration minimizes the direct high-velocity impingement of damp debris with the inner wall of the cell nearest the point of entry. 
         [0017]    Two cell end sections are formed within the cell by vertical baffles that extend from the cell top portion partway into the cell bottom portion. Air is withdrawn through cell exhaust plenums located in the top of each cell end section. Cell exhaust plenums in both cell end sections contain cell exhaust outlets. Cell exhaust plenum inlets, disposed in both cell end sections, may comprise filters or inlet ducts in the top portion of each end section. 
         [0018]    Damp debris and dry debris exhibit significant differences in their air handling characteristics, which can affect the buildup of damp debris within the cell and the efficiency of separation. Two embodiments, a flexible impaction shield and a damp debris grate, minimize the buildup of damp debris. Two additional embodiments, internal baffles and a dry debris grate, maximize the separation efficiency with dry debris. 
         [0019]    Gravity settling of debris occurs along all or most of the flow path within the cell and debris is collected within the bottom portion of the cell and periodically removed by manual or automatic means. Collected debris, which is a by-product of the cleaning operation, can be disposed of or it can be used, among other things for leveling under the landscape fabric or plastic sheet to restore the rock bed. 
         [0020]    The exhaust air from the air-debris cell flows to a vacuum source, consisting of a vacuum blower or a mechanical vacuum pump and a dust collector such as a bag collector, where the dust collector is located after blower or before the pump, depending on which device is used to generate the vacuum. 
         [0021]    In another embodiment of the invention, the intake means may be connected directly to the rock-debris separation chamber, thereby eliminating the entry section; though its inclusion in the apparatus is preferred. 
         [0022]    The foregoing embodiments of the invention satisfy the operational requirements of a portable apparatus for picking up and cleaning landscape rock and other similar solids, the need for which is well understood. 
         [0023]    In another embodiment of the invention, an apparatus is disclosed that vacuums up debris only, including moist or damp debris, and collects the debris so that it can be disposed of appropriately. This embodiment includes an intake means, an air-debris separator cell, a debris collection means, and a vacuum means, but not a rock-debris separator chamber. 
         [0024]    In another embodiment of the invention, an apparatus is disclosed that vacuums up both rock and debris, in which the cleaned rock is collected for reuse, but which does not include an air-debris separator cell. 
         [0025]    The above described features and other features and advantages of this invention and the manner of realizing them will become more apparent, and the invention itself will be best understood, from a study of the following description and appended claims, with reference to the attached drawings showing the preferred embodiments of the invention. It should be understood that the particular specifications, configurations or geometrical relationships of the invention are exemplary only and are not to be regarded as limitations of the invention. Nor is the invention, particularly as it pertains to the rock-debris separator chamber, in any way invalidated by the substitution of alternative means of separation of air and debris or particulate matter that are well-known to those skilled in the art. Further, the applicability of the invention is not limited to on-site cleaning of landscape rock using a portable version of this invention. The invention described herein may also be used in larger-scale stationary operations to which rock is routinely hauled from many sites. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a side view of one embodiment of the present invention in use. 
           [0027]      FIG. 2  is a side view of the embodiment of the invention of  FIG. 1 . 
           [0028]      FIG. 3  is a side cross-sectional view of an embodiment of the rock debris separator chamber and collection container of the invention of  FIG. 1 . 
           [0029]      FIG. 4  is a side cross-sectional view of another embodiment of the chamber and collection container of the invention of  FIG. 1 . 
           [0030]      FIG. 5  is a side cross-sectional view of another embodiment of the chamber and collection container of the invention of  FIG. 1 . 
           [0031]      FIG. 6  is a side cross-sectional view of another embodiment of the chamber and collection container of the invention of  FIG. 1 . 
           [0032]      FIG. 7  is a side cross-sectional view of another embodiment of the chamber and collection container of the invention of  FIG. 1 . 
           [0033]      FIG. 8  is a side cross-sectional view of the air-debris separator cell of the invention of  FIG. 1 . 
           [0034]      FIG. 9  is a side cross-sectional view of the chamber, collection container and air-debris separator cell of the invention of  FIG. 3 . 
           [0035]      FIG. 10  is a side cross-sectional view of the chamber, collection container and air-debris separator cell of the invention of  FIG. 5 . 
           [0036]      FIG. 11  is an end view of the air-debris separator cell of the invention of  FIG. 1 . 
           [0037]      FIG. 12  is an end view of the air-debris separator cell of the invention of  FIG. 1  opposite the end of  FIG. 11 . 
           [0038]      FIG. 13  is a side view of another embodiment of the invention. 
           [0039]      FIG. 14  is a side view of a component of one embodiment of the invention. 
           [0040]      FIG. 15  is side view of another embodiment of the invention. 
           [0041]      FIG. 16  is a side view of another embodiment of the invention. 
           [0042]      FIG. 17  is a phantom perspective view of the air-debris separator of one embodiment of the invention. 
           [0043]      FIG. 18  is a cross-sectional end view of the air-debris separator of  FIG. 17  at a particular location along the air-debris separator. 
           [0044]      FIG. 19  is a cross-sectional end view of the air-debris separator of  FIG. 17  at a different particular location along the air-debris separator than the view of  FIG. 18 . 
           [0045]      FIG. 20  is a cross-sectional top view of the air-debris separator of  FIG. 17  at a particular location along the air-debris separator. 
           [0046]      FIG. 21  is a cross-sectional side view of the air-debris separator of  FIG. 17  at a particular location along the air-debris separator. 
           [0047]      FIG. 22  is a phantom perspective view of the air-debris separator of  FIG. 17  showing the dry debris gate of one embodiment of the invention. 
           [0048]      FIG. 23  is a cross-sectional end view of the air-debris separator of  FIG. 17 . 
           [0049]      FIG. 24  is a cross-sectional end view of the air-debris separator of  FIG. 17  at a particular location along the air-debris separator showing the flow of air and debris when the invention is in operation. 
           [0050]      FIG. 25  is a cross-sectional end view of the air-debris separator of  FIG. 17  at a particular location along the air-debris separator showing the flow of air and debris when the invention is in operation. 
           [0051]      FIG. 26  is a cross-sectional end view of the air-debris separator of  FIG. 17  at a particular location along the air-debris separator. 
           [0052]      FIG. 27  is a side view of the air-debris separator of  FIG. 17 . 
           [0053]      FIG. 28  is a phantom top view of the air-debris separator of  FIG. 17 . 
           [0054]      FIG. 29  is a phantom side view of the air-debris separator of  FIG. 17  showing the flow of air and debris when the invention is in operation. 
           [0055]      FIG. 30  is a cross-sectional end view of the air-debris separator of another embodiment of the invention at a particular location along the air-debris separator. 
           [0056]      FIG. 31  is a cross-sectional end view of the air-debris separator of another embodiment of the invention at a particular location along the air-debris separator. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0057]    For the purposes of this patent the terms defined in this section shall have the following meanings unless otherwise provided, described or indicated by the context.
   Debris is defined as a mixture of one or more of the following: soil, inorganic materials such as silt, or sand and organic materials such as decomposing or decomposed leaves, grass clippings, plant clippings, seeds, sticks and weeds, all accompanied by varying amounts of moisture.   Landscape rock or rock is defined as any naturally occurring rock or stone, both as is or crushed, or similar man-made solid materials used as a landscape material, having a specific gravity of at least 1.25, and with the linear dimension of the particles ranging from about 0.5 inches to about 3.5 inches.   Solids are defined as any solid materials, including rock used for other purposes, both naturally occurring and man-made, which have a variety of end uses requiring cleaning or separation, with a specific gravity of at least 1.25.   Airflow or airstream are used interchangeably and are defined as a flow of air resulting from the application of vacuum which airflow or airstream may contain entrained rock, dirt or debris.   
 
       Throughout this description, an element referred to by a reference number has the characteristics and attributes described in association with that element wherever such element is referred to unless specifically directed otherwise. 
       [0062]    First an overview of the invention is presented followed by a detailed description of the invention. The invention is an apparatus, generally labeled  10 , for on-site cleaning of landscape rock as shown in  FIG. 1 . By cleaning of landscape rock we mean that the landscape rock is being separated from the dirt and debris that had accumulated in the interstitial spaces around the individual rocks and that was also picked up by the vacuum. The apparatus  10  can, of course, be used to clean other solids. The apparatus  10  can also be set up to operate at a fixed location where rock or solids are brought to it rather than bringing the apparatus  10  to a site. 
         [0063]    The apparatus  10  operates under vacuum and, in one embodiment, includes the following main elements. An intake  20  suctions rock and associated debris off the ground and conveys it either directly to a rock-debris separator chamber  40  or to the rock-debris separator chamber  40  through an entry section  30  ( FIG. 1 ). The flow is preferably directed in a slightly downward direction as it passes through entry section  30  to chamber  40 . Rock impacting the inner walls of intake  20 , entry section  30 , if used, and chamber  40  as well as inter-rock collisions and turbulent airflow serves to dislodge adhering debris from the rock. Ambient air is drawn into the lower part of chamber  40  or into chamber collector means  70  below chamber  40  through chamber air supply means  80  ( FIG. 3 ), which includes a valve to control the flow of ambient air, and flows generally upward toward a chamber exhaust outlet  52  in the chamber top portion  50  of the chamber  40 . Rock traveling and falling through chamber  40 , and chamber discharge outlet  56  passes through this generally upward flow of air that entrains the lighter debris but not the denser rock. Consequently, the cleaned rock continues on a downward path where it is accumulated in chamber collector means  70  and is ready to be put back in place. 
         [0064]    The settling of rock in chamber  40  is facilitated by a reduction of the velocity of the flow in chamber  40  by use of a pre-exhaust  90  abruptly withdrawing air from entry section  30  or chamber  40  and the greater size of chamber  40  relative to intake  20  and entry section  30 . 
         [0065]    An air-debris separator cell  100  is provided to remove debris from the airflow moving from pre-exhaust outlet  94  and chamber exhaust outlet  52 . The air-debris separator cell  100  is designed so the debris settles out of the air by gravity and is collected separately for periodic removal. 
         [0066]    A vacuum means  130  creates a vacuum to establish the necessary airflow in apparatus  10 . The function of the vacuum means  130  is to draw ambient air into apparatus  10  through intake means  20 , chamber air supply means  80 , and auxiliary chamber air supply means  82 , resulting in the rock and debris being picked up and transported through the apparatus  10 , the rock being cleaned by separating rock from the debris, and the rock and debris being collected separately. Vacuum means  130 , which includes a dust collector  136 , discharges to the atmosphere. 
         [0067]    Because damp debris is prone to adhering to the inner surfaces of the apparatus  10  when the air stream carrying the debris impacts the surfaces at a high velocity and/or at an acute angle, several measures, each of which is an independent invention, have been taken in the design of the apparatus  10  to minimize this problem. They include: removing the debris from the air stream as quickly as possible by the use of an air-debris separator cell  100  situated directly above the chamber  40 ; keeping connecting conduits as short and straight as possible; avoiding, as much as possible, the high velocity contact of debris-containing air streams directly onto the inner surfaces of the apparatus  10 ; provision of an auxiliary air supply means  82  into the chamber  40 , and the use of flexible impaction shields  84  and  86  as will be described hereafter. 
         [0068]    A detailed description of the invention follows. Those portions of the apparatus  10  in contact with rock must be made of durable materials able to resist the abrasion and impact of the moving rock. In the preferred embodiment of the invention, rock and associated debris are suctioned into the apparatus  10  through intake  20  ( FIG. 2 ), which comprises a hose  24  having a head  22  at one end and an outlet  25  at the other end. The head  22  picks up rock and debris and provides entry to the hose  24  and the remainder of the apparatus  10 . Head  22 , hose  24  and outlet  25  must be of a size to receive the rock. 
         [0069]    Hose  24  can be a hose, conduit or a flexible assembly of rigid metal or plastic piping configured to allow the head  22  to move in three dimensions. The hose  24  connects through outlet  25  to an entry section  30  ( FIG. 3 ) or directly to rock-debris separator chamber  40  ( FIG. 4 ). Entry section  30 , as shown in  FIG. 3 , is not required for the apparatus  10  to function, but it is preferred. Entry section  30  is horizontally disposed and comprises an entry section inlet  32 , an entry section outlet  34  opposite the entry section inlet  32 , an entry section top portion  36  and an entry section bottom portion  38 . The entry section inlet  32  receives the flow from hose  24  at outlet  25 . The entry section outlet  34  discharges the flow from entry section  30  to rock-debris separator chamber  40 . The entry section top portion  36  generally slopes downward from the horizontal toward the entry section bottom portion  38  from the entry section inlet  32  to the entry section outlet  34 , guiding the flow downward from the horizontal direction thereby imparting a downward component to the direction of flow leaving the entry section outlet  34  if an entry section  30  is employed. 
         [0070]    A rock-debris separator chamber or chamber  40  separates debris from rock as shown in  FIGS. 3 and 4 . Chamber  40  comprises a chamber inlet side  42  with a chamber inlet  44  having a chamber inlet uppermost point  45 , a chamber opposite side  46  opposite the chamber inlet side  42 , a chamber access  48 , a chamber top portion  50  having a chamber exhaust outlet  52 , a chamber bottom portion  54  having a chamber discharge outlet  56  and a chamber partition  58 . 
         [0071]      FIG. 4  shows an embodiment of the apparatus  10  with the entry section  30  removed. In this embodiment, the hose  24  is connected directly to the chamber inlet side  42 . 
         [0072]    The chamber inlet  44  is oriented approximately vertically and is preferably part of and parallel to the chamber inlet side  42  in the immediate vicinity of chamber inlet  44 . The chamber inlet  44  has a chamber inlet uppermost point  45  at the highest elevation of chamber inlet  44 . The chamber inlet  44  receives flow from the entry section outlet  34  if an entry section  30  is used ( FIG. 3 ) or from hose  24  outlet  25  if directly connected to intake  20  ( FIG. 4 ). The chamber bottom portion  54  slopes downward toward the chamber discharge outlet  56 . The chamber discharge outlet  56  extends downward from the chamber bottom portion  54 . A chamber access  48  is disposed on the chamber  40  to provide access to the inside of chamber  40  from outside chamber  40 . The chamber access  48  includes a sealed removable cover or hatch to provide access to the inside of chamber  40  for inspection, cleaning and repair. 
         [0073]    Pre-exhaust  90  abruptly withdraws a portion of the air entering the apparatus  10  through the intake  20  to reduce the velocity of the remaining flow in chamber  40 . Pre-exhaust  90  comprises a pre-exhaust inlet  92  proximate the chamber inlet  44 , a pre-exhaust outlet  94  opposite the pre-exhaust inlet  92  and a pre-exhaust midsection  96 , a closed conduit connecting the pre-exhaust inlet  92  to the pre-exhaust outlet  94 . The pre-exhaust inlet  92  is located near the chamber inlet  44  and directs a portion of the airflow entering the intake  20  into the pre-exhaust midsection  96  where it is directed to the pre-exhaust outlet  94 . 
         [0074]    Pre-exhaust  90  is formed, in part, by chamber partition  58 . Chamber partition  58  can have many shapes and configurations including a simple plane that approximately faces the chamber inlet  44 .  FIGS. 3 and 4  show the preferred embodiment with the chamber partition  58  having a partition lower portion  60  with a partition lower edge  62  both below a partition upper portion  64  with a partition upper edge  66 . The function of the chamber partition  58  is to split the airflow entering chamber  40  through chamber inlet  44  and forms in part the pre-exhaust  90 . 
         [0075]    The partition upper portion  64  is pivotally connected to partition lower portion  60  at pivot point  68  so that partition upper portion  64  can be rotated to control the relative flow areas on each side of the partition upper portion  64  in the chamber exhaust outlet  52 . Partition lower edge  62  is generally horizontal and set preferably at or slightly above the elevation of the chamber inlet uppermost point  45  so that most if not all of the passing rock does not impact the partition lower edge  62  or partition lower portion  60 . Partition lower edge  62  could be set higher, as high as proximate the chamber top portion  50 , but with diminishing effect. Partition lower edge  62  could also be set lower than the preferred elevation, but would then be exposed to the impact of rock and debris. 
         [0076]    The pre-exhaust inlet  92  in this preferred embodiment is a planar area formed by a plane through and bounded by the partition lower edge  62  and chamber inlet uppermost point  45  and the intersection of that plane with the chamber inlet side  42 . Pre-exhaust outlet  94  is formed within the chamber exhaust outlet  52  and is a planar area formed by the partition upper edge  66  and the chamber exhaust outlet  52  on the chamber inlet side  42  of the chamber exhaust outlet  52 . The pre-exhaust mid-section is bounded by chamber partition  58  and the chamber inlet side  42 , and by the pre-exhaust inlet  92  and the pre-exhaust outlet  94 . 
         [0077]    There are three other embodiments of the pre-exhaust  90  that do not require the chamber partition  58  to form the pre-exhaust  90 . A second embodiment shown in  FIG. 5 , includes an entry section  30  with an entry section exhaust outlet  98  connected to a pre-exhaust inlet  92  to abruptly withdraw air from the entry section  30  between the entry section inlet  32  and the entry section outlet  34 . The pre-exhaust midsection  96  may be a structure separate from chamber  40  depending on the proximity of the entry section exhaust outlet  98  to chamber  40 . 
         [0078]    A third embodiment shown in  FIG. 6  is a special case of the second embodiment and includes the entry section exhaust outlet  98  immediately adjacent to the entry section outlet  34  next to the chamber inlet side  42 . Entry section exhaust outlet  98  is connected to a pre-exhaust inlet  92  to abruptly withdraw an air steam from the entry section  30  proximate the chamber inlet side  42 . The pre-exhaust midsection  96  may have a portion in common with chamber  40  along part or all of its length. 
         [0079]    The fourth embodiment, shown in  FIG. 7 , includes a chamber inlet side exhaust outlet  99  proximate the chamber inlet  44  and connected to the pre-exhaust inlet  92  for the abrupt withdrawal of air from the chamber  40  proximate the chamber inlet  44 . The pre-exhaust midsection  96  can be adjacent to or separate from the chamber  40 . 
         [0080]    Now, turning to the other elements connected to the chamber  40 , a chamber collector means  70  is disposed adjacent to and below the chamber discharge outlet  56 . The chamber collector means  70  comprises a collection container  72  such as a common five gallon pail which is removable and has an airtight connection to the chamber discharge outlet  56  when the apparatus  10  is operating. Alternatively, the chamber collector means  70  may be one or more integral hoppers that discharge to other containers or onto a conveyer. 
         [0081]    A chamber air supply means  80 ,  FIGS. 3 and 4 , draws ambient air into the chamber discharge outlet  56  through collection container  72  by one or more adjustable inlets such as orifices or nozzles. Alternatively, or in conjunction with chamber discharge outlet  56  ( FIG. 14 ), ambient air is drawn directly into chamber discharge outlet  56  by one or more adjustable inlets  81  such as orifices or nozzles. The purpose for the introduction of air that flows upward and countercurrent to the rock falling through the chamber discharge outlet  56  is to entrain debris but not the denser rock. Further, this vertical airflow influences the transition to totally vertical flow transporting debris from chamber  40 . An auxiliary chamber air supply means  82 , shown in  FIGS. 3 and 4 , comprises one or more adjustable air inlets such as nozzles and orifices. Auxiliary chamber air supply means  82 , shown in  FIG. 3 , directs an airflow into chamber  40  such as through the chamber opposite side  46  and works in conjunction with chamber flexible impaction shield  84  to minimize the build up of debris within chamber  40 . 
         [0082]    An air-debris separator cell  100  shown in  FIG. 8  is preferably interposed between chamber  40  and vacuum means  130 . Air-debris separator cell  100  reduces the concentration of debris in the flow from the pre-exhaust outlet  94  and the chamber exhaust outlet  52  by decreasing the velocity of the flow within air-debris separator cell  100  to allow gravity settling of debris out of the air before discharge from air-debris separator cell  100 . Further, air-debris separator cell  100  is positioned as in  FIGS. 9  and  10 , adjacent to and above chamber  40 , resulting in a short and straight run of conduit between the rock-debris chamber  40  and the air-debris separator cell  100 . 
         [0083]    The air-debris separator cell  100  comprises a cell middle section  102 , a first end section  104 , a second end section  106 , a cell bottom portion  108 , a cell top portion  110 , a vertical baffle  116 , a cell exhaust plenum  119  with associated inlet duct  140  ( FIGS. 26 and 28 ), filter  118  and exhaust outlet  114 . Inlet duct  140  has inlets  145  and  141 . There is a cell pre-exhaust inlet  112  to receive flow from pre-exhaust outlet  94  and a cell chamber exhaust inlet  113  to receive flow from chamber exhaust outlet  52 , as shown in  FIG. 10 , or a single cell inlet  111  if the pre-exhaust outlet  94  and chamber exhaust outlet  52  are combined prior to entering the air-debris separator cell  100 , as shown in  FIG. 9 . 
         [0084]    To simplify the remaining description concerning the air-debris separator cell  100  only the single cell inlet  111  embodiment is described but the same description applies as well to the embodiment of air-debris separator cell  100  with the cell pre-exhaust inlet  112  and separate cell chamber exhaust inlet  113 . 
         [0085]      FIGS. 9 ,  11  and  12  show embodiments of air-debris separator cell  100 . Although air-debris separator cell  100  can assume many shapes and cross-sectional area configurations, here air-debris separator cell  100  is substantially a closed oval cylinder with a horizontal axis  144 . The cylindrical shape of the air-debris separator cell  100  produces an outer circumference  147  when viewed from the end of the air-debris separator cell  100 . This circumference  147  is defined by a radius extending from the horizontal axis  144  to the circumferential surface of the air-debris separator cell  100 . This cylindrical shape also adds rigidity to the air-debris separator cell  100 , and in combination with the rock-debris separator chamber  40 , forms a rigid frame that allows the entire apparatus  10  to have a compact and therefore highly mobile configuration. The rigidity of the air-debris separator cell  100  also allows it to be able to accommodate a range of debris removal means  122 , particularly an auger. 
         [0086]    Two vertical baffles  116  are disposed in the cell top portion  110  that extend downward from top portion  110  toward cell bottom portion  108 , forming cell middle section  102 , first end section  104  on one side of cell middle section  102 , and a second end section  106  on the opposite side of cell middle section  102 . 
         [0087]    Air-debris separator cell  100  may have many possible arrangements of cell inlet  111  and cell exhaust outlet  114 . Here cell inlet  111  is approximately vertical and disposed in the cell bottom portion  108  of the cell middle section  102  and extends into air-debris separator cell  100 . The vertical cell inlet  111  is further located to enter air-debris separator cell  100  at a point on the circumference of the bottom portion  108  such that the vertical extension of the centerline of cell inlet  111  intersects the radius from the axis  144  at a point within about 70-90 percent of the distance along the radius from the axis  144 . 
         [0088]    A cell exhaust plenum  119  containing exhaust outlet  114  is disposed internal or external of cell top portion  110  of first end section  104  and a second exhaust plenum  119  and exhaust outlet  114  is similarly disposed in the second end section  106 . Exhaust plenum inlet comprises filter  118  or an array of inlets  145  and  141  connected by ducts  140  to the exhaust plenum and disposed in the cell top portion  110  of each end section  104  and  106  ( FIGS. 9 ,  26 ,  27  and  28 ). The cell exhaust plenum outlets  114  are fluidly connected to the vacuum means  130  through a vacuum manifold  139  connected to a main vacuum conduit  138  that is in turn connected to the vacuum means  130 . The vacuum manifold  139  and main vacuum conduit  138  may take many forms clear to those skilled in the art so long as the cell exhaust plenum outlets  114 , and consequently the cell exhaust plenum  119 , are fluidly connected to the vacuum means  130 . 
         [0089]    In the preferred embodiment of the invention, shown in  FIG. 9 ,  10  and elsewhere, the velocity of the airflow in the air-debris separator cell  100  is slowed substantially by the airflow entering the large air-debris separator cell  100  at cell inlet  111 . As the airstream enters the air-debris separator cell  100 , the greater volume of the air-debris separator cell  100  causes the cross-sectional area of the airstream to increase which causes the airstream velocity to slow down, which in turn causes the airstream to lose much of its ability to move the entrained debris along with the airstream. As a result, the entrained debris falls to the bottom of the air-debris separator cell  100 . 
         [0090]    In essence, the flow into the air-debris separator cell  100  has the highest velocity at the point of entry into the air-debris separator cell  100  at cell inlet  111 , from which the flow disperses rapidly, follows the inner surface of the cell middle section  102  of the air-debris separator cell  100 , rising initially (i.e., moving toward the cell top portion  110 ) then turning and flowing downward (i.e, moving toward the cell bottom portion  108 ). As the airflow moves downward, it separates increasingly into two streams, each of which flows under a vertical baffle  116  and then upward (i.e., moving toward the cell top portion  110 ) through filter  118  or inlet ducts  140  through exhaust plenum  119  to the cell exhaust outlet  114  ( FIGS. 9 ,  26 ,  27  and  28 ). The momentum of the debris being carried downward in airstreams that turn upward, combined with the effect of gravity, causes settling to take place. The filter  118 , if used, not only serves to capture light bulky debris such as pieces of leaves, but it provides a pressure drop through filter  118  that results in a more uniform flow over the cross-section of filter  118  and through end sections  104  and  106 , which in turn results in further gravity settling to take place within end sections  104  and  106 . 
         [0091]    A cell collector  120 , shown in  FIGS. 11 ,  12  and  13 , is disposed in the cell bottom portion  108  and collects the separated and settled debris. A cell debris removal means  122 , shown in  FIGS. 13 and 23 , removes the collected debris as needed. A cell access  124  allows entry into the air-debris separator cell  100  and access to the cell collector  120  and the cell debris removal means  122 . 
         [0092]    As explained above, the airstream velocity slows upon entering the large volume of the air-debris separator cell  100 , and also by friction with the inner wall of the air-debris separator cell  100 . In conjunction with the physical location of cell inlet  111  in the cell bottom portion  108 , it has been found to be desirable to make the air-debris separator cell  100  somewhat elongated in the vertical direction so that the airstream entering the air-debris separator cell  100  at cell inlet  111  has a greater distance or time to disperse before contacting the inner wall of the cell top portion  110  of the air-debris separator cell  100 . The greater vertical dimension also favors gravity settling by allowing more time for the debris to settle out of the airflow before the air is exhausted from air-debris separator cell  100 . 
         [0093]    An alternative is provided to filter  118  being used as an inlet to exhaust plenum  119 . The filter  118  provides an even distribution of airflow in end section  104  and  106 , as previously stated, but may require a high level of filter maintenance in some applications. The preferred embodiment ( FIGS. 26 ,  27 ,  28  and  29 ) employs one or more inlet ducts  140  connected to each exhaust plenum  119  in the top portion  110  of each end section  104  and  106  and includes inlets  145  and optional inlet  141 . Vertical baffles  116  define the boundary between the middle section  102  and the first and second end sections  104  and  106  respectively. The air and debris that transitions from cell middle section  102  to end sections  104  and  106  flows through a large opening or expanse under vertical baffle  116  in the cell bottom portion  108  and also through an optional outlet in baffle  116  located 90 degrees from cell inlet  111  flow. Inlet ducts  140  have inlets  145  strategically sized and located to balance the vertical airflow out of each end section  104  and  106 , and an optional inlet  141  connected directly through baffle  116 . 
         [0094]    The purpose of inlet  141  is to remove a portion of the air directly from cell middle section  102  to reduce the rate of flow of the remaining airflow moving under vertical baffle  116 , thus increasing the opportunity for the entrained debris to fall to the cell collector  120 . The air removed through inlet  141  is relatively void of heavy particulates because the air is extracted from the side of the entering airflow and the momentum of the debris is aligned with and in the same direction of the main airflow. 
         [0095]    Using inlet ducts  140  as described with the optional but preferred inlet  141 , it is believed that about 70-90% of the air entering the air-debris separator cell  100  passes below vertical baffle  116  through the cell bottom portion  108  and about 10-30% through baffle  116  at inlet  141  and consequently out of the air-debris separator cell  100 . Using inlet ducts as described without optional inlet  141 , 100% of the air entering the air-debris separator cell  100  passes below vertical baffle  116 . 
         [0096]    This movement of air from the cell inlet  111  around the inside of the air-debris separator cell  100  is shown in  FIG. 29 . As can be seen, the airstream entering the air-debris separator cell  100  generally follows the inner contour of the cell entering in an upward direction and then turns downward between the baffles  116 . The airflow then splits, moving toward and under baffles  116 , and into end sections  104  and  106 . By “splits”, we mean that a portion of the air is directed in one direction and the remaining portion directed in another direction. Thereafter, the airstream moves toward exhaust plenum inlet duct inlets  145  or the filter  118  if used and toward the vacuum means  130  through the vacuum manifold  139  and vacuum conduit  138 . 
         [0097]    Air-debris separator cell  100  further comprises at least one bottom flow control baffle  117 , as shown in  FIGS. 19 and 20 . A top flow control baffle  115  is located in cell middle section  102 , as shown in  FIGS. 19 ,  21  and  24 . A dry debris grate  121  and a damp debris grate  123  both located in cell bottom portion  108 , as shown in  FIGS. 22 and 23 . In the preferred embodiment, a flexible impaction shield  86  is located in the cell middle section  102 , as shown in  FIGS. 30 and 31 . 
         [0098]    Damp debris and dry debris have significant differences in their air handling characteristics; damp debris weighs more and readily settles out of an airstream but is prone to building up on the inner surfaces of air-debris separator cell  100  due to the direct high velocity impact of the debris containing airstream with the inner surfaces as previously discussed. Dry debris is more difficult to remove from an airstream because it is lighter, and once it does settle out by gravity action, it may re-enter the airstream unless shielded from the main airflow. Excessively damp or wet debris is not recommended for this application. 
         [0099]    To achieve the best performance of the air-debris separator cell  100 , the operator determines if the debris is damp or dry and sets up the apparatus accordingly. For dry debris this involves installing a top flow control baffle  115  ( FIGS. 19 and 21 ) and a dry debris grate  121  ( FIGS. 22 and 24 ). For damp debris only the damp debris grate  123  is used ( FIGS. 23 and 25 ). 
         [0100]    Bottom flow control baffles  117  are permanently positioned in cell middle section  102  above the cell collector  120  on opposite sides of the cell collector  120  to produce a first bottom flow control baffle  128  and a second bottom flow control baffle  129 . The first bottom flow control baffle  128  is located on the side of the cell collector  120  nearest inlet  111  and directs the airstream impacting the first bottom flow control baffle  128  from above over the collector means  120  ( FIGS. 19 and 24 ). The second bottom flow control baffle  129  is located on the side of the cell collector  120  farthest from the inlet  111  and directs the airstream impacting the second bottom flow control baffle  129  from above over the collector means  120  ( FIGS. 19 and 24 ). As a result, air flow approaching either bottom flow control baffle  117  from above will be directed to flow approximately to and across the top of the cell collector  120  ( FIGS. 19 and 24 ). 
         [0101]    When the air-debris separator cell  100  is set up for damp debris, a damp debris grate  123  is positioned in or adjacently above the cell collector  120 . The damp debris grate  123  consists of a series of parallel plates  127  parallel to the horizontal axis of the air-debris separator cell  100 . Each plate  127  preferably increases in height moving from the inner wall opposite the cell inlet towards the cell inlet  111 . The function of the damp debris grate  123  is to interact with and turn the airstream flowing across the top of collector means  120  to distribute more of the damp debris in end sections  104  and  106  of collector means  120  ( FIG. 25 ). 
         [0102]    When the air-debris separator cell  100  is set up for dry debris, a dry debris grate  121  is positioned in or adjacently above the cell collector  120 . The dry debris grate consists of a series of parallel plates  125  placed along the horizontal axis of the air-debris separator cell  100 , as can be seen in  FIG. 22 . As dry debris settles out of the airstream as described above, it will fall downward between the dry debris plates  125 . The dry debris grate  121  minimizes interaction between the collected debris and the air, thereby preventing re-entrainment of the debris. 
         [0103]    When the air-debris separator cell  100  is set up for dry debris, a top flow control baffle  115  is positioned in cell top portion  110  of cell middle section  102  opposite the inlet side and against the inner wall of the air-debris separator cell  100  ( FIG. 21 ). The top flow control baffle  115  is by-directional in that the incoming airflow encounters top flow control baffle  115  and is directed or forced into taking two down stream flow paths that are approximately balanced. 
         [0104]    One function of the top flow control baffle  115  is to direct a portion of the airstream impacting the top flow control baffle  115  toward and across the interior of the cell middle section  102  where it can contact the airstream entering the air-debris separator cell  100  through cell inlet  111  in a direction substantially opposed to or at substantially a right angle ( FIG. 24 ). This contact between airstreams will cause the velocities of the airstreams to slow slightly thus reducing the ability of these airstreams to entrain the debris. As a result, some of the debris will fall to the cell collector  120 . Some of the flow contacting cell inlet  111  will merge with cell inlet flow and recycle with little consequence. 
         [0105]    The majority of the flow directed across the interior of cell middle section  102  by baffle  115  goes around inlet  111  and follows the inner contour of the cell middle section downward wherein it contacts the first bottom flow control baffle  128  from above which in turn directs the flow over the cell collector  120 . 
         [0106]    The other function of top flow control baffle  115  is to provide an airstream down the inner wall of the air-debris separator cell  100  in middle section  102  opposite the cell inlet  111  ( FIG. 24 ). Likewise this flow strikes the second bottom flow control baffle  129  farthest from the inlet  111  from above and is directed over collector means  120 . These opposing airflows (airflow directed over collector means  120  by striking the bottom flow control baffle  117  located nearest inlet  111  and airflow directed over collector means  120  by striking the bottom flow control baffle  117  located opposite the inlet  111 ) collide in the cell bottom portion  108  of cell middle section  102 . This causes the velocity of each airstream to slow down at least momentarily and disperse before exiting cell middle section  102  enroute to end sections  104  and  106 . This results in a substantial reduction of the ability of the airstream to entrain the debris, thus allowing the debris to fall to the cell collector  120 . 
         [0107]    Specific structures have been disclosed for top flow control baffle  115 , vertical baffles  116 , bottom flow control baffle  117 , ducts and sections which have the function of directing one or more airstreams into configurations that cause the airstreams to lose velocity with the concomitant effect of causing the entrained debris to fall to the cell bottom portion  108  of the air-debris separator cell  100 . However, it is understood that other arrangements and configurations of top flow control baffle  115 , vertical baffles  116 , bottom flow control baffle  117 , ducts and sections could be used as will occur to those skilled in the art after evaluating the description of the invention contained herein that also cause the airstreams to lose velocity and, therefore, their ability to retain entrained debris. It is intended that these other arrangements and configurations fall within the scope of the invention. 
         [0108]    As mentioned above, build-up of damp debris can occur on interior surfaces of the apparatus  10  at specific locations and develop to the point of interrupting airflow. This is problematic and directly related to the composition of the debris, moisture content, impaction force of the airflow and the angles of impaction involved. By flexing the base to which impacted debris bonds, the adhering debris will break up and either fall downward by gravity or be carried away in the airflow. 
         [0109]    Flexible impaction shield  86  utilizes the aforementioned principle and is attached near, and above inlet  111  of the air-debris separator cell  100 . The impaction shield  86  ( FIGS. 30 and 31 ) is preferably made of a heavy duty flexible sheet material like mylar and has a reasonable duty life. When vacuum is applied, the airflow opens inlet cap  87  and positions the impaction shield  86  against the interior surface of the cell middle section  102  by contact between the airflow and the impaction shield  86 . The impaction shield  86  covers the main impact area of cell inlet  111  flow and allows impaction to occur on its exposed surface facing the airflow. When vacuum is interrupted such as at rock bucket exchange interval when there is little or no airflow through the apparatus  10 , the impaction shield  86  departs from the “up” position and falls away from the cell inner surface allowing the impaction shield  86  to flex on the way down (i.e, in the direction of the cell bottom portion  108  by the pull of gravity), and when airflow is resumed, it will flex again on the way up (i.e, in the direction of the cell top portion  110  by the push of the airstream). In both motions the impacted debris will break away from the impaction shield  86  and either fall to the cell collector  120  or be carried away in the airflow for later removal. Inlet cap  87  closes when airflow is interrupted to prevent falling debris from entering the rock-debris separator  40 . 
         [0110]    A chamber flexible impaction shield  84  substantially similar to the impaction shield  86  described, may be placed in the rock-debris separator chamber  40 , opposite and facing the chamber inlet  44  flow ( FIGS. 3 and 4 ). The chamber flexible impaction shield  84  relies on the modulation of vacuum levels within the chamber  40  as occurs during normal operation. For example, when picking up rock and debris, the airflow necessary to pick up the rock and debris causes the vacuum level in the chamber  40  to increase. This increase allows more airflow to enter through auxiliary chamber air supply means  82  located behind flexible impaction shield  84 , resulting in a flexing movement of the impaction shield  84  and corresponding dislodgement of debris, allowing debris to be carried out of the chamber  40  with the airflow. 
         [0111]    Cell collector  120  preferably includes a trough or depression along the bottom of the air-debris separator cell  100 . Several cell debris removal means  122  are possible such as manual removal of debris using a hand rake-like tool or an auger ( FIGS. 8 and 23 ) through the cell access  124  ( FIG. 8 ). 
         [0112]    Vacuum means  130  preferably comprises a positive displacement vacuum pump preceded by dust collector  136  or a centrifugal vacuum blower followed by a dust collector  136  and powered by blower motor  134  ( FIGS. 1 ,  2 ,  15  and  16 ). Ambient air is drawn through the apparatus  10  by vacuum means  130 , while dust collector  136  removes dust and fine particulate matter that hasn&#39;t been captured previously, thereby minimizing the discharge of dust to the environment. Other types of dust collectors  136  may be used as will be clear to those skilled in the art, but the bag filter is the preferred method of collection for this application. 
         [0113]    It is desirable to control the vacuum applied by vacuum means  130  to provide the necessary flexibility for handling a variety of materials and maximum productivity. For example, the vacuum may be controlled by varying the speed of the blower motor  134  or by regulating the airflow through adjustable air inlets  80 ,  81  and  82  as shown. 
         [0114]    In use, the apparatus  10  is moved into position where the head  22  can be near the rock that is to be cleaned. The cell debris removal means cell access  124  is closed so that adequate vacuum can be obtained in the apparatus  10 . The vacuum means  130  is activated so that vacuum is generated throughout the device and particularly at intake  20  head  22 . Head  22  is placed next to the rock that is to be cleaned whereby the vacuum causes the rock to enter and move through the hose  24  of the intake  20 . Under this vacuum, an airstream is created whereby both rock and the associated debris on and around the rock will be brought to and through the intake  20 . In all uses of the apparatus  10 , if the rock bed is tightly compacted, it may be necessary to loosen the rock or debris by mechanical means such as a pick or shovel or by a rigid claw extending from the head  22 . 
         [0115]    Upon flowing through the intake  20 , the rock and debris moves into the entry section  30  if used and rock-debris separator chamber  40  where the rock is separated from the debris and is collected in the collection container  72 . The air, along with the debris moves to the air-debris separator cell  100  where the debris is captured in the air-debris separator cell  100 , shown in  FIGS. 1 ,  2 ,  9  and  10 . 
         [0116]    The preferred embodiment of the invention provides a method of vacuuming up and separating landscape rock or other solids from associated dirt and debris and thereafter collecting the cleaned rock and separating the debris from the discharge air. This method involves the use of an apparatus  10  having a rock-debris separator chamber  40  and an air-debris separator cell  100 , as described above. With this apparatus  10 , the user applies sufficient vacuum at the head  22  of intake  20  to cause rock and debris to be pulled into the hose  24 , whereafter the airstream leaving hose  24  is directed into the rock-debris separator chamber  40 , or, optionally, through the entry section  30  into the rock-debris separator  40 . Inside the rock-debris separator chamber  40 , the rock is separated from the air and debris as described above. Thereafter, this method includes directing the airstream leaving the rock-debris separator chamber  40  into the air-debris separator cell  100  through the cell inlet  111  or cell pre-exhaust inlet  112  and cell chamber exhaust inlet  113  where both are used. Inside the air-debris separator cell  100 , the debris is separated from the air as described above and collected for reuse or disposal. 
         [0117]    The preferred embodiment includes a method of cleaning rock. This method includes taking an airstream containing rock and slowing the velocity of the airstream down within the chamber to the point where the airstream can no longer entrain the rock whereupon the rock falls by gravity out of the airstream towards a chamber discharge outlet. This slowing of the velocity of the airstream is accomplished by expanding or increasing the cross-sectional area in which the airstream flows or by abruptly removing a portion of the airstream proximate the chamber inlet  44 , or both, resulting in a reduction of the velocity of the airflow traversing through chamber  40 . 
         [0118]    In this method, debris picked up with the rock will typically be less dense than the rock. As a result, the airstream will continue to entrain most of the debris at a lower velocity than is required to entrain rock. Of course, some of the debris may fall with the rock towards the chamber discharge outlet  56 . The chamber  40  has a chamber air supply means  80  that allows an airflow to be drawn vertically through the chamber discharge outlet  56 . This vertical airflow in the chamber discharge outlet  56  is intense enough to entrain the debris but not intense enough to overcome the momentum of the falling rock. The balance of the airstream entering the chamber  40  through the chamber inlet  44  and the airstream entering the chamber  40  through the chamber air supply means  80  merge in the chamber  40  and carry debris out of the chamber  40  through the chamber exhaust outlet  52 . 
         [0119]    In addition, the invention also includes another method of cleaning rock in the airstream that picks up rock or debris or both at the intake head  22  of intake  20 . This method is an independent method in itself but is preferably combined with the method of cleaning rock described above. This method includes vacuuming up landscape rock by whatever means and causing the rocks vacuumed up to collide with each other and the sides of the vacuum hose  24  in a turbulent airflow to dislodge dirt and debris from the rocks. As a result, the rocks have been cleaned in that a portion of the dirt or debris has been separated from the rocks. 
         [0120]    The air-debris separator cell  100  includes a method of separating air from debris, including any rock that may be present. This method includes directing the airstream into configurations that disperse the airstream, split the airstream into smaller segments, impede the airstream or a combination thereof, to slow the velocity of the airstream down to the point that the airstream is unable to entrain the debris. The debris and any rock present fall under the influence of gravity to the cell collector  120 . 
         [0121]    This method of directing an airstream commences as the airstream containing debris is directed vertically into the air-debris separator cell  100  through cell inlet  111  located on the bottom portion  108  of the air-debris separator cell  100 . The airstream disperses as it leaves the confines of cell inlet  111  and enters the relatively large area of the cell middle section  102 . The flow continues to disperse as it follows the inner contour of the cell middle section  102  located between the two vertical baffles  116 , rising initially then, through contact with the cell top portion  110 , turning downwards towards the cell bottom portion  108 . As the flow passes the confines of vertical baffles  116 , the airstream increasingly splits and is drawn toward the cell exhaust plenums  119  located in the cell top portion  110  of the first end section  104  and second end section  106 . As stated above, the cell exhaust plenums  119  preferably have a horizontal array of inlets  145  that further segments and disperses the vertical airflow approaching the cell exhaust plenum  119  in each respective first end section  104  and second end section  106 . 
         [0122]    In addition to the method described above, a top flow control baffle  115  is preferably utilized when the use of the apparatus  10  involves dry debris. This top flow control baffle  115  is used to improve the operational efficiency of the apparatus  10  with dry debris. This method also includes a method of directing an airstream wherein the initial downward flow of the airstream in the cell middle section  102 , as indicated above, is further directed by the top flow control baffle  115  into at least one additional downward flow path. Both downward flow paths are then directed to contact the bottom flow control baffles  117  from above where the bottom flow control baffles  117  direct the downward flow across the cell collector  120 . Both bottom flow control baffles  117  direct the airflows contacting them across the cell collector  120  resulting in substantially head-on contact from opposing airflows that occurs over the top of the cell collector  120 . These opposing airflows impede air movement, at least momentarily slowing the velocity of the airstream down and providing another opportunity for the suspended debris to fall from the airstream into the cell collector  120 . 
         [0123]    A preferred embodiment of the invention also includes a method of preventing the build up of impacted debris on selected interior surfaces of the apparatus  10 . This is accomplished by use of flexible impaction shields  84  and  86 . Each flexible impaction shield  84  and  86 , consisting of a sheet like material as described above, is suspended over a site prone to impaction by debris. When such impaction occurs, it will form on the side of the shield  84  or  86  facing the airflow that produces the impaction. As routine changes to the airflow occur, the flexible impaction shield  84  and  86  will flex, bend and flap, therein dislodging the impacted debris from the shields  84  and  86  into the airstream. 
         [0124]    Although the preferred embodiment of apparatus  10  includes both a rock-debris separator chamber  40  and an air-debris separator cell  100 , in another embodiment of the invention shown in  FIG. 15 , the apparatus  10  does not include the air-debris separator cell  100 . In this method of operation, the pre-exhaust outlet  94  and the chamber exhaust outlet  52  are connected to the vacuum means  130  directly through the vacuum manifold  146  and vacuum conduit  138  so that there is no air-debris separator cell  100 . In all other respects, the apparatus  10 , including chamber  40 , is as described above. 
         [0125]    In the former embodiment, an apparatus  10  is provided having a rock-debris separator chamber  40  as described above. With this apparatus  10 , the user applies sufficient vacuum at head  22  of intake  20  to cause rock to be pulled into the hose  24  in an airstream containing air, rock and debris whereafter the airstream is directed into the rock-debris separator chamber  40  through the chamber inlet  44  or the entry section  30  if used and then through the chamber inlet  44 . Inside the rock-debris separator chamber  40 , the rock is separated from the air and debris as described above. Because this embodiment does not separate debris from the air prior to vacuum means  130 , the invention is preferentially intended to pick up and clean rock containing only a small quantity of dry debris. 
         [0126]    In yet another embodiment of the invention shown in  FIG. 16 , the apparatus  10  does not include the rock-debris separator chamber  40 . In this method of operation, the intake  20  is connected directly to the air-debris separator cell  100  at cell inlet  126 . Air-debris separator cell  100  in this embodiment is substantially as described above except that cell inlet  126  replaces the single cell inlet  111  or the pre-exhaust inlet  112  and chamber exhaust inlet  113 . In this method of operation, both rock and debris are separated from the airstream flowing through the air-debris separator cell  100  and collected for reuse or disposal. As in the aforementioned methods, the user applies sufficient vacuum at the head  22  of intake  20  to cause debris to be pulled into the hose  24 , from which it flows directly into the air-debris cell  100  when the rock-debris separator  40  is not used. Of course, where rock is present with debris, the apparatus  10  will pick up the rock with the debris. In this embodiment, the apparatus  10  does not separately remove rock and debris from the airstream picked up at head  22 . Instead, this embodiment removes debris and any rock picked up in the airstream as described above. Because this embodiment does not separate any rock from debris, this embodiment of the invention is preferentially intended to be used to collect debris including moist or damp debris and minimal rock. 
         [0127]    The present invention has been described in connection with certain embodiments. It is to be understood, however, that the description given herein has been given for the purpose of explaining and illustrating the invention and are not intended to limit the scope of the invention. For example, specific examples of the means for creating vacuum pressure have been shown. However, it is clear that an almost infinite number of ways of producing sufficient vacuum could be used as is well understood by those skilled in the art. Consequently, it is intended that all such sources of vacuum are included in the present invention. It is to be further understood that changes and modifications to the descriptions given herein will occur to those skilled in the art. Therefore, the scope of the invention should be limited only by the scope of the following claims and their legal equivalents.