Patent Publication Number: US-8117711-B2

Title: High efficiency intake hood system for mobile sweeper vehicles

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application 60/985,625 filed Nov. 5, 2007 in common assignment herewith. 
    
    
     BACKGROUND OF THE INVENTION 
     Various types of vehicles have been developed to sweep or vacuum debris from pavements, roadways, and streets. In general, these vehicles can be classified as mechanical broom sweepers, air sweepers, and combinational variants thereof. 
     Mechanical broom sweepers use a motor-driven broom or brooms to mechanically sweep paper, plastic, litter, trash, vegetation (leaves, twigs, grass clippings, etc.), asphalt and concrete debris, and larger sand or gravel particles toward a conveyor for transport into a debris collection hopper. 
     Regenerative air sweepers use a motor-driven fan to create a high-velocity recirculating air flow to aspirate dust, particulates, and other debris from the pavement or street surface through an intake or pickup hood carried or suspended beneath the sweeper vehicle. Optionally, a gutter broom is often mounted adjacent one or both lateral sides of the intake hood to brush debris into the path of the intake hood, and a powered brush roll can be mounted with or contained within the intake hood to assist in dislodging particulates from the swept surface for entrainment into the air flow. 
     In a typical regenerative system, a motor-driven fan develops a high-volume, high-velocity recirculating air-flow through an intake or pickup hood that is positioned on or closely adjacent the pavement surface. As the intake hood is moved along the pavement surface, debris is aspirated into the air flow and carried by ducting into and through a debris-collecting hopper or container. As the debris-laden air enters the debris-collecting hopper, the velocity of the air flow is reduced sufficiently so that many particulates drop out the air stream with various types of baffles, screens, grates, panels, etc. causing additional particulates to drop out of the air flow and collect in the hopper. 
     It is known that some of the air flow in the intake hood can escape from beneath one or more of the various sides of the hood into the ambient environment; that escaping air flow can carry entrained particulates, known as ‘fugitive’ particles, into the ambient environment and undesirably contribute to the concentration of airborne particulates surrounding the cleaning vehicle. The issue of fugitive particles has been addressed by placing one or more elastomeric flaps or curtains along the perimeter edges of the intake hood; the flaps or curtains extend from the edges of the intake hood to the ground surface being sweep to minimize or otherwise limit the escape of fugitive air flows. Additionally, some systems are designed to vent some of the pressurized filtered air into the atmosphere prior to introduction into the intake hood to create a situation in which ambient make-up air is drawn into the intake hood to militate against the release of fugitive particulates. Since the volume of air introduced into the intake hood is large and the overall velocity of the primary air flow is large, subsidiary air flows can nonetheless be established that escape from beneath the intake hood. 
     SUMMARY 
     An improved pickup or intake hood for a roadway/pavement cleaning vehicle, such as a wheeled regenerative roadway/pavement sweeper, includes an intake hood having a central compartment into which air is introduced from the outlet of a recirculation fan at a high-velocity to entrain dust, particulates, and the like therein and from which the particulate-entrained air flow is provided via appropriate ducting to a dust separation system to remove the entrained material with the remaining air flow provided to the inlet of a recirculation fan. Dust conduits lead from appropriately shrouded gutter brooms into a flow control manifold or selector box that allows dust from one or both of the gutter brooms to be drawn into a duct for transport to the dust separation system. The intake hood is provided with at least one auxiliary compartment adjoining or adjacent the primary air flow compartment and into which any fugitive air flows from the primary air flow compartment can enter. The auxiliary compartment is in air flow communication with the dust separation system via ducting connected to the dust separation system so that any fugitive particulates are directed into the dust separation system to minimize the escape of fugitive dust and particulates. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIGS. 1 and 2  are right and left side elevation views of a sweeper vehicle in accordance with the present invention; 
         FIG. 3  is a top view of the sweeper shown in  FIGS. 1 and 2 ; 
         FIG. 4   a  is a top view of a first intake hood and gutter broom configuration; 
         FIG. 4   b  is a top view of a second intake hood and gutter broom configuration; 
         FIG. 4   c  is an enlarged top view of a flow-control selector or manifold shown in  FIG. 4   a  and in  FIG. 4   b;    
         FIG. 4   d  is a top view of the flow-control selector or manifold of  FIG. 4   c , in partial cross-section, showing an internal adjustable vane; 
         FIG. 5  is a top view of the intake hood of  FIG. 4   a;    
         FIG. 6  is a rear elevational view of the intake hood of  FIG. 5 ; 
         FIG. 7  is a side elevational view of the intake hood of  FIG. 6 , taken along line  7 - 7  of  FIG. 6 , with a side panel removed to reveal an interior compartment; 
         FIG. 8  is a bottom view of the intake hood of  FIG. 6 ; 
         FIG. 9  is an enlarged view of the right side of the intake hood shown in  FIG. 8 ; and 
         FIGS. 10   a  and  10   b  show the second intake hood configuration of  FIG. 4   b  in top and bottom view. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An exemplary pavement/street cleaning vehicle with a dust/particulate separation system in accordance with the preferred embodiment is shown in right and left side views in  FIGS. 1 and 2  and is generally designated by the reference character  20 ; the particular sweeper configuration shown is representative of sweepers manufactured by Schwarze Industries, Inc. of Huntsville, Ala. 35811 under the DXR designation. 
     As shown in  FIGS. 1 and 2 , the truck-mounted sweeper system  20 , which can be mounted on a commercial truck chassis, includes a pickup head or debris-intake hood  100  carried beneath the truck frame  24 , an optional gutter broom  26  that is mounted forwardly of the debris-intake hood  100  on one or both sides thereof (as shown in the top view of  FIG. 3 ), and a power unit  28  that includes (not specifically shown) a high-volume, high-velocity radial flow fan  30 , an internal combustion engine for driving the fan  30 , and associated hydraulic pump(s), air compressor(s), and various accessory and related equipment as is known in the art. The radial flow fan  30  may take the form of the fan disclosed in U.S. patent application Ser. No. 09/528,168 filed Mar. 17, 2000 (now abandoned), the disclosure of which is incorporated herein by reference. 
     A debris separation system  200  is mounted rearwardly of the power unit  28  and functions as part of the air-flow recirculation loop to receive and accumulate debris that is aspirated or swept from the roadway surface. The debris separation system  200  includes a rear door  202  that is opened and closed by a hydraulic cylinder  204  as well as various inspection and/or access doors, generally indicated at  206 . 
     As shown in  FIG. 1 , debris-laden air moves from the intake hood  100  through an intake duct  102  into the debris separation system  200  where particulates, dust, debris, etc. are separated. The air moves into the debris separation system  200  and through various baffles, grates, screens, etc. (not shown) to cause some of the entrained dust, particulates, etc. to drop out of the air flow. After passing through the debris separation system  200 , the air is passed into and through the fan  30  and then through ducting  104  ( FIG. 2 ) into the intake hood  100  to complete the air-flow recirculation loop. A filtered air bleed-off valve or port (not shown) is provided to bleed-off a measured quantity of the filtered air from the fan  30  into the ambient atmosphere to create a situation in which “make-up” air drawn from beneath the intake hood  100  into the recirculation air flow loop. 
     The intake hood  100  extends laterally substantially across the side-to-side width of the truck chassis from a driver side to the non-driver side of the vehicle. The intake hood  100  is typically suspended below the truck chassis  24  by links, bars, or chains (not specifically shown), or a combination thereof, so that the intake hood  100  can ride on or above the surface to be sweep as the sweeper vehicle  20  moves forward. As best shown in the plan views of  FIGS. 4   a ,  4   b ,  5 , and  10   a , the intake hood  100  is configured as a generally rectangular structure having two shorter sides and two longer sides, one of the longer sides facing in the forward direction as indicated by the FWD arrows in the various figures. The intake hood  100  includes a primary air compartment  100 -P ( FIG. 8 ) into which air is introduced from the fan  30  to entrain at least some of any dust or particulates on the roadway surface for passage through the duct  102  to the debris separation system  200 . After passage through the debris separation system  200 , the air flow enters the fan  30  to continue the recirculation loop. 
     As shown in  FIG. 4   a , the gutter brooms  26  are enclosed by appropriate shrouds  26 - 1  to control dust with dust conduits  106  and  108  (which can be fabricated from an elastomeric material or a resilient shape-sustaining semi-rigid plastic or plastic/metal combination) connected to a flow-control selector or manifold  110  that, in turn, connects via a conduit  112  into the intake duct  102 . Thus, at least some of the dust/debris that is made airborne by the rotary motion of the gutter brooms  26  can be contained within their respective shrouds and transferred to and into the intake duct  102  for removal in the separation system  200 . 
       FIG. 4   b  illustrates a second configuration for the gutter brooms  26  and the dust conduits  106  and  108  in which the each dust conduit is branched into two separate sub-ducts at the gutter broom  26 . As shown, sub-ducts  106   a  and  106   b  join through a “Y” connection (unnumbered) into the duct  106 , and sub-ducts  108   a  and  108   b  join through a “Y” connection (unnumbered) into the duct  108 . 
       FIG. 4   c  is an enlarged plan view of the flow-control manifold  110  of  FIG. 4  and shows a user operable knob  110 - 1  at or near the remote end of an indicator arm  110 - 2  that is attached of a pivot pin or axle  110 - 3 . As explained in relationship to  FIG. 4   d , the operator can counter-rotate the knob  110 - 1  to unlock the indicator arm  110 - 2  to move the indicator arm  110 - 2  clockwise or counterclockwise to another position and rotate the knob  110 - 1  to tighten and lock the indicator  110 - 2  into its new position. 
       FIG. 4   d  is a plan view, in partial cross-section, of the flow-control manifold  110  of  FIG. 4  and shows an internal axle-mounted panel or vane  114  that is connected to the indicator arm  110 - 2 ; the vane  114  is manually rotated counterclockwise to the left (as represented by dashed line  114 - 1 ) by the machine operator to substantially block flow from the conduit  106  so that flow from the conduit  108  is preferentially moved into and through the flow-control manifold  110  and through the ducting  112  into the intake duct  102 . In a similar manner, the vane  114  can be rotated clockwise to the right (as represented by dashed line  114 - 2 ) by the machine operator to substantially block flow from the conduit  108  so that flow from the conduit  106  is preferentially moved into and through the flow-control manifold  110  and through the ducting  112  and into the intake duct  102 . Is not necessary that the vane  114  completely block the air from the conduit  106  or  112 ; it is sufficient that a substantially majority of the flow is blocked from entering the manifold  110 , since some “blow-by” is expected. As can be appreciated, when the vane  114  is in some intermediate position (as shown in solid line), air flow from both the ducts  106  and  112  will enter the manifold  110  since neither of the ducts  106  and  112  are no longer substantially blocked. Thus, when the gutter broom  26  on the left in  FIG. 4   a  or  4   b  is sweeping against a curbstone, the vane  114  is positioned to substantially block flow from the conduit  108  to favor air flow from the left gutter broom  26  through conduit  106  into the intake duct  102  via the ducting  112 , and, conversely, when the gutter broom  26  on the right in  FIG. 4   a  or  4   b  is sweeping against a curbstone, the vane  114  is positioned to substantially block flow from the conduit  106  to favor air flow from the right side gutter broom  26  through conduit  108  into the intake duct  102  via the ducting  112 . As shown in the view of  FIG. 8 , the ducting  112  connects to an opening  112 - 1  in the inlet ducting  102  with the arrow  112 - 2  representing the air flow thereinto. 
     Additionally, the flow-control manifold  110  includes an opening  116  that extends through the top surface or ‘deck’ of the intake hood  100  through to a forward auxiliary vacuum plenum or compartment  122 , described below in relationship to  FIGS. 7-10   b.    
     In those cases where the vehicle is not equipped with gutter brooms  26  (for example, when sweeping leaves), the fittings  110 - 4  and  110 - 5  on the flow-control manifold  110  onto which the dust conduits  108  and  106 , respectively, are attached can be closed off with caps (not shown) or appropriate plugs, for example. Where the vehicle is equipped with only one gutter broom  26 , the appropriate fitting  110 - 4  or  110 - 5  with closed off with a cap. 
     As shown on the left in the representative view of the intake hood  100  in  FIG. 5 , on the right in  FIG. 6 , and in the end view of  FIG. 7 , an auxiliary inlet conduit  118  connects the intake duct  102  to an auxiliary lateral or side plenum  120  in the intake hood  100  through an opening  118 - 1 . The side plenum  120 , which is shown in cross-section in  FIG. 7  and in the bottom-side views of  FIGS. 8 and 9 , aspirates dust/particulates that enter into the side plenum  120  and through an opening  118 - 1  into the intake duct  102  via the auxiliary inlet conduit  118 . Thus, as shown in  FIG. 9 , any fugitive air flows and any fugitive dust escaping from beneath the partition  120 - 1  enters into a volume from which an air flow is being continuous drawn via the conduit  118  into the intake duct  102  to thus minimize the escape of fugitive particulates. 
     As shown in  FIGS. 7 and 8 , a forward, laterally extending auxiliary vacuum plenum  122  is defined between the forward face  100 - 1  of the intake hood  100  and a partition  124  with the auxiliary vacuum plenum  122  communicating via the opening  116  ( FIG. 4   b ) in the flow-control manifold  110  and a corresponding opening in the deck of the intake hood  100  with the conduit  112  and the intake duct  102 . Thus, as shown in  FIG. 7 , any fugitive air flow or flows and any fugitive dust or particles escaping from beneath the partition  124  enter into the auxiliary plenum  122  and are continuously drawn via the opening  116  and the conduit  112  into the intake duct  102  to thus also minimize the escape of fugitive particulates from the primary air compartment of the intake hood  100 . 
     The auxiliary plenums  120  and  122  thus each function to aspirate dust and particulates from the surface being swept and to also re-direct or capture any fugitive dust or particulates that may escape from the primary sweeping compartment. 
       FIGS. 5-9  show single auxiliary plenum  120  on one side of the intake hood  100 ; if desired and a shown in  FIGS. 10 and 11 , a second auxiliary plenum  120 - 1  can be provided on the opposite side of the intake hood  100  from that shown in  FIG. 5  with a conduit  118 - 1  connecting that air flow to the intake duct  102 . The various auxiliary plenums  120 ,  120 - 1 , and  122  are shown as next to or immediately contiguous the shorter side or sides (plenums  120 ,  120 - 1 ) or the longer side (plenum  122 ) of the primary air flow chamber; as can be appreciated, the auxiliary plenums can be spaced from or somewhat adjacent the primary flow chamber provided the plenums are sufficiently close thereto to capture any escaping fugitive air flows or dust/particulates therefrom. 
     Filtered air enters the primary air flow compartment of the intake hood  100  via the filtered-air conduit  104  (from the outlet of the fan  30 ) and is forced through a narrow-width slot  128  to create an “air blade” or “air knife” that is effective to energized particulates on the pavement or roadway surface (including particulates within cracks and fissures) and aspirate or entrain the particles into the air flow beneath the intake hood  100  and then through the intake duct  102  as shown by the arrow  130 . Any fugitive air flows from the primary air flow compartment of the intake hood  100  escaping therefrom into the lateral auxiliary plenum  120  (or  120 - 1 , or both) or into the auxiliary plenum  122  are captured prior to escape into the ambient atmosphere. 
     The intake hood  100  shown in  FIGS. 1 and 2  does not include an associated powered broom; if desired an intake hood with an integrated broom can be provided, for example, as described in U.S. Pat. No. 5,884,359 issued Mar. 23, 1999 to A. Llbhart, the disclosure of which is incorporated herein by reference. 
     The organization of the sweeper unit  20  is configured so that air flow through the intake hood  100  is from the driver side of the vehicle to the non-driver side of the vehicle, as is conventional in the industry. If desired, the sweeper can be configured so that air flow through the intake hood  100  is from the non-driver side to the driver side as disclosed in U.S. patent application Ser. No. 11/407,293 filed Apr. 20, 2006, the disclosure of which is incorporated herein by reference. 
     As will be apparent to those skilled in the art, various changes and modifications may be made to the illustrated embodiment of the present invention without departing from the spirit and scope of the invention as determined in the appended claims and their legal equivalent.