Patent Publication Number: US-8985701-B2

Title: Cold planer having multi-inlet exhaust system

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to a cold planer and, more particularly, to a cold planer having a multi-inlet exhaust system. 
     BACKGROUND 
     Asphalt-surfaced roadways have been built to facilitate vehicular travel. Depending upon usage density, base conditions, temperature variation, moisture variation, and/or physical age, the surface of the roadways can eventually become misshapen, non-planar, unable to support wheel loads, or otherwise unsuitable for vehicular traffic. In order to rehabilitate the roadways for continued vehicular use, spent asphalt is removed in preparation for resurfacing. 
     Cold planers, sometimes also called road mills or scarifiers, are machines that typically include a frame quadrilaterally supported by tracked or wheeled drive units. The frame supports an engine, an operator&#39;s station, and a milling drum. The milling drum, fitted with cutting tools, is rotated through a suitable interface by the engine to break up the surface of the roadway. 
     During the milling process, dust is produced by the cutting tools that can be a nuisance to machine operators. In addition, bituminous vapors may be produced due to high temperature friction of the cutting tools. 
     One attempt to control the dust and vapors produced during roadway milling is disclosed in U.S. Pre-Grant Publication No. US 2010/0327651 (“the &#39;651 publication”), published on Dec. 30, 2010, and submitted by Cipriani et al. In particular, the &#39;651 publication discloses a means of sealing the dust and vapors produced during the milling process from exiting the milling machine prior to the point of discharge of the milled road material. The sealing means create a continuous chamber above material conveyors and in a joint connection area among them. The continuous chamber is designed to be free from external air channels and is formed by sidewalls of the milling drum housing, a rear mouldboard and side plates. A suction device is located on the milling machine and connected to the continuous chamber. The suction device is able to create a depression that draws dust and polluted air from the continuous chamber, and routes the same to a filtering and discharge system. 
     Although the system of the &#39;651 publication may be capable of controlling dust and fumes generated during the roadway milling process, the system may still be problematic. In particular, an efficiency of the suction device is dependent upon the continuous chamber being well-sealed. As it is presently constituted, the sealing means of the &#39;652 publication includes a multitude of components. Given the number of sealing components associated with the continuous chamber it is likely that gaps in the sealing means will arise overtime. In addition, on account of the number of components involved and the degree of customization of the components specific to a unique milling machine model, it is unlikely that the suction system of the &#39;652 publication could easily be applied and/or retrofitted to other models of milling machines. 
     The cold planer and exhaust system of the present disclosure solves one or more of the problems set forth above and/or other problems in the art. 
     SUMMARY 
     In one aspect, the present disclosure relates to an exhaust system for a cold planer. The exhaust system may include an inlet manifold located downstream of a milling drum and above a material conveyor. The inlet manifold may be configured to receive dust and fumes generated by the milling drum. The exhaust system may also include at least one inlet passage located at a side of the material conveyor and gravitationally lower than the inlet manifold. The at least one inlet passage may be configured to receive dust and fumes generated by the milling drum. The exhaust system may further include a ventilator in fluid communication with the inlet manifold and the at least one inlet passage. The ventilator may be configured to draw the dust and fumes from the inlet manifold and the at least one inlet passage. 
     In an other aspect, the present disclosure may be related to an other exhaust system for a cold planer. This exhaust system may include an inlet manifold located downstream of a milling drum and above a first material conveyor. The inlet manifold may be configured to receive dust and fumes generated by the milling drum. The exhaust system may also include at least one inlet passage located at a transition area between the first material conveyor and a second material conveyor. The at least one inlet passage may be configured to receive dust and fumes generated by the milling drum. The exhaust system may further include a ventilator in fluid communication with the inlet manifold and the at least one inlet passage. The ventilator may be located at a discharge end of the second material conveyor and configured to draw the dust and fumes from the inlet manifold and from the at least one inlet passage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial cross-sectional illustration of an exemplary disclosed cold planer; 
         FIG. 2  is a pictorial illustration of an exemplary disclosed exhaust system that may be used in conjunction with the cold planer of  FIG. 1 ; 
         FIG. 3  is a pictorial illustration of an alternative embodiment of an exemplary disclosed exhaust system that may be used in conjunction with the cold planer of  FIG. 1 ; and 
         FIG. 4  is an enlarged pictorial illustration of a portion of the exhaust system of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     For the purpose of this disclosure, the term “asphalt” may be defined as a mixture of aggregate and asphalt cement. Asphalt cement may be a brownish-black solid or semi-solid mixture of bitumens obtained as a byproduct of petroleum distillation. The asphalt cement may be heated and mixed with the aggregate for use in paving roadway surfaces, where the mixture hardens upon cooling. A “cold planer” may be defined as a machine used to remove layers of hardened asphalt from an existing roadway. It is contemplated that the disclosed cold planer may also or alternatively be used to remove cement and other roadway surfaces. 
       FIG. 1  illustrates an exemplary cold planer  10  having an exhaust system  60 . Exhaust system  60  may be attachably integrated with a milling system  30  and a debris removal system  40  of cold planer  10 . It is contemplated that exhaust system  60  may be integrated with additional components and systems within cold planer  10 , if desired, such as an auxiliary power system (not shown). 
     Cold planer  10  of  FIG. 1  may include a frame  12  supported by one or more front ground engaging units  14  and one or more rear ground engaging units  16 . Ground engaging units  14  and  16  may each include either a wheel or a track section that is pivotable in one or more directions. Ground engaging units  14  and/or  16  may be connected to lifting columns  18 , which may be adapted to controllably raise and lower frame  12  relative to the associated ground engaging units  14  and  16 . 
     Frame  12  may support an operator&#39;s station  20  having a steering command element  22  and a controller  24 . Steering command element  22  is shown to include a steering wheel, but other steering devices such as a joystick or levers could be used as well. Controller  24  may send control signals to one or more actuators (not shown) of the following: ground engaging units  16  and  18 , lifting columns  18 , milling system  30 , debris removal system  40  and exhaust system  60 . In the case of electrically activated actuators, the control signals may act directly on the respective actuators. In the case of hydraulically activated actuators, the control signals may act on valves, which in turn control flows of pressurized fluid to the actuators. Controller  24  may be a separate control unit or may be part of a central control unit operable to control additional functions of cold planer  10 . 
     Frame  12  may also support a water tank  26 , an engine  28  such as an internal combustion engine, and milling system  30 . Engine  28  may supply power to drive one or more of ground engaging units  14  and  16  to propel cold planer  10  relative to a road surface  11 . In one embodiment, this is accomplished by driving a hydraulic pump with an output of engine  28 , which in turn supplies high-pressure hydraulic fluid to individual motors associated with ground engaging units  14  and  16 . This conventional hydraulic drive is well-known in the pertinent art and is therefore not depicted in the drawings. Engine  28  may also supply power to milling system  30  to break up road surface  11 . 
     Milling system  30  may include various components that interact to remove asphalt from roadway surface  11 . Specifically, milling system  30  may include a milling drum  32 , a plurality of cutting tools  34 , a water nozzle  36  and a milling drum housing  38 . Cutting tools  34  may be attached to milling drum  32  in any manner known in the art. During the milling process, cutting tools  34  may be frictionally heated on account of their sustained contact with roadway surface  11 . Water nozzle  36  may spray water on milling drum  32  and its associated cutting tools  34  during the operation of milling system  30  to cool the same. Milling system  30  may be configured to remove a layer of asphalt from the entire width of roadway surface  11  or from only a portion of roadway surface  11  at varying depths and contours. The broken-up road material may be carried away from cold planer  10  by debris removal system  40 . 
     Debris removal system  40  may include various components that cooperate to remove milled asphalt from milling system  30 . Specifically, debris removal system  40  may include a primary conveyor  42 , a secondary conveyor  50 , and a transition area  44  located between primary conveyor  42  and secondary conveyor  50 . Cutting tools  34  may be configured to deliver milled asphalt onto a charge end  41  of primary conveyor  42  as milling drum  32  rotates towards primary conveyor  42 . As the milled asphalt exits a discharge end  43  of primary conveyor  42 , the milled asphalt may strike against a weldment  48  located within transition area  44 . Transition area  44  may be an enclosed box-like structure formed by a cover plate  46 , and two or more side plates  47 . Upon coming into forced contact with weldment  48 , the milled asphalt may break apart and fall onto a charge end  49  of secondary conveyor  50 . The milled asphalt, being transported by secondary conveyor  50 , may be kept from exiting secondary conveyor  50  prematurely (i.e., kept from spilling off the sides) by a secondary conveyor housing  52 . Secondary conveyor  50  may discharge the milled asphalt at a discharge end  51 . The milled asphalt may be off-loaded to any appropriate transport vehicle  58 , such as an on-highway haul truck, an off-highway articulated or non-articulated truck, or any other type of transport vehicle known in the art. In the disclosed embodiment, secondary conveyor  50  may need to move somewhat relative to primary conveyor  42 . For example, secondary conveyor  50  may need to move in side-to-side and/or up-and-down motions as it facilitates the discharge of milled asphalt to a moving transport vehicle  58 . 
     During the milling process, dust may be produced on account of the breaking up of road surface  11 . In particular, relatively large quantities of dust may be produced at milling drum  32 , and when the milled asphalt is further broken down by coming into contact with weldment  48  in transition area  44 . Bituminous vapors may also be produced due to high temperatures created by the friction of cutting tools  34  against road surface  11 . Exhaust system  60  may be attachably integrated with milling system  30  and debris removal system  40  to help control the dust and fumes generated during operation of cold planer  10 . 
     As illustrated in  FIGS. 1 and 2 , exhaust system  60  may include various components that cooperate to remove dust and fumes during the operation of cold planer  10 . Specifically, exhaust system  60  may include an inlet manifold  62 , at least two inlet extensions  66 , and at least two inlet connectors  64 . Inlet manifold  62  may be an elongated steel fabricated hood connected to inlet extensions  66  at opposing ends by inlet connectors  64 . Inlet manifold  62  and inlet extensions  66  may each have openings through which dust and fumes are drawn into exhaust system  60 . In one exemplary embodiment, inlet manifold  62  may be placed directly above primary conveyor  42  (referring to  FIG. 1 ), with inlet extensions  66  oriented to the sides of primary conveyor  42 . In one embodiment, inlet extensions  66  may be gravitationally lower than inlet manifold  62 , extending downward to the lateral sides of primary conveyor  42 . Inlet extensions  66  may extend to a point at which they are likely to draw in a desired amount of dust and fumes, but unlikely to draw in larger fragments of milled material. Both inlet manifold  62  and inlet extensions  66  may be placed downstream of milling drum  32 . In one exemplary embodiment, inlet manifold  62  and inlet extensions  66  may be placed at about 300-800 mm downstream of milling drum  32  so as to avoid drawing in larger fragments of milled material thrown into the air by cutting tools  34 . Dust and fumes generated by milling system  30  may be routed to inlet manifold  62  and inlet extensions  66  via suction produced by a ventilator  78 . 
     Dust and fumes collected at inlet manifold  62  and inlet extensions  66  may be drawn through an arrangement of pipes and flexible tubes and/or hoses to ventilator  78 , where the collected dust and fumes may be delivered to secondary conveyor  50  within secondary conveyor housing  52 . As illustrated in  FIG. 2 , the arrangement of pipes and flexible tubes of exhaust system  60  may include, among other things, a plurality of flexible fittings  68 , a plurality of rigid pipes  70 , first and second flexible hoses  72  and  76 , and a junction  74 . Flexible fittings  68  may be fabricated from an elastomer, for example rubber, and connected at one end to inlet connectors  64  and at an opposing end, (i.e., at connection  69 ), to rigid pipes  70 . Rigid pipes  70  may be connected to flexible hoses  72 , and run generally parallel to primary conveyor  42  with one rigid pipe  70  located at each side of water tank  26 . Junction  74  may receive the combined air flow of flexible hoses  72  and route the same to flexible hose  76 . In one exemplary embodiment, rubber fittings  68 , connections  69 , rigid tubes  70  and flexible hoses  72  may be between about 3-5 inches in diameter, and flexible hose  76  may be between about 7-9 inches in diameter. Flexible hose  76  may connect junction  74  to ventilator  78 . Certain components of exhaust system  60  (e.g., flexible fittings  68 , flexible hoses  72  and flexible hoses  76 ) may need to be flexible so as to be able to move with the up-and-down and side-to-side motions of secondary conveyor  50 . 
     Ventilator  78  may create a depression within exhaust system  60 , such that the air pressure outside inlet manifold  62  and inlet extensions  66  is greater than the air pressure within exhaust system  60 . Consequently, dust and polluted air generated from the operation of milling system  30  may be drawn in and routed through exhaust system  60  to secondary conveyor  50  within secondary conveyor housing  52 . In one embodiment, ventilator  78  may have a cast aluminum fan wheel disposed within a steel fan housing, and may be powered by a hydraulic motor (not shown). 
     In one exemplary embodiment, exhaust system  60  may be removably attached to cold planer  10  at one or more attachment points  71 , as shown in  FIG. 1 . Attachment points  71  may include any number of various rigid, elastic or plastic types of fasteners, clamps, joints, links, couplings or other mechanical attachment mechanisms. In one exemplary embodiment, attachments  71  may connect rigid pipes  70  to water tank  26  and ventilator  78  to secondary conveyor housing  52 . As rigid pipes  70  may be removably attached to the exterior of water tank  26 , as opposed to running through water tank  26 , exhaust system  60  may be easily removed from cold planer  10 . Upon removal of exhaust system  60  from cold planer  10 , the insertion points of exhaust system  60  (e.g. where the airway of ventilator  78  may enter into secondary conveyor housing  52 ) may be plugged by any number of various different types of plugs, caps, fillers, fittings or stoppers. 
     An alternative exhaust system  80  is shown in  FIG. 3 . Like exhaust system  60  of  FIG. 2 , exhaust system  80  of  FIG. 3  may include inlet manifold  62 , flexible fitting  68 , rigid pipes  70 , attachment points  71 , and flexible hose  72 . In contrast to exhaust system  60 , however, exhaust system  80  may omit inlet extensions  66 . Instead, exhaust system  80  may include secondary inlet hoses  82  that, in one exemplary embodiment, may be associated with transition area  44 . Both inlet manifold  62  and secondary inlet hoses  82  may be placed downstream of milling drum  32 . In one exemplary embodiment, inlet manifold  62  may be placed at about 300-800 mm downstream of milling drum  32 , and secondary inlet hoses  82  may be inserted into transition area  44  at about 300-800 mm upstream of weldment  48  so as to avoid drawing in larger fragments of milled material. Dust and fumes generated by milling system  30  and at weldment  48  may be routed to inlet manifold  62  and secondary inlet hoses  82 , respectively, via suction produced by a ventilator  92 . 
     Dust and fumes collected at inlet manifold  62  and secondary inlet hoses  82  may be drawn through an arrangement of pipes and flexible tubes and/or hoses to ventilator  92 , where the collected dust and fumes may be delivered to secondary conveyor  50  within secondary conveyor housing  52 . Like exhaust system  60  of  FIG. 2 , exhaust system  80  of  FIG. 3  may include flexible fitting  68 , connection  69 , rigid pipes  70 , attachment points  71 , and flexible hoses  72 . In contrast to exhaust system  60 , exhaust system  80  may also include hose connectors  84  and flexible hoses  86 . Flexible fittings  68  may be fabricated from an elastomer, for example rubber, and connected on one end to inlet manifold  62  and on an opposing end (i.e., at connection  69 ), to rigid tubes  70 . Rigid tubes  70  may be connected to flexible hoses  72  and run generally parallel to primary conveyor  42 , with one tube located on each side of water tank  26 . Hose connectors  84  may receive the combined air flow of flexible hoses  72  and secondary inlet hoses  82  and route the same to flexible hoses  86 . In one exemplary embodiment, rubber fittings  68 , connections  69 , rigid tubes  70  and flexible hoses  72  may be between about 3-5 inches in diameter, secondary inlet hoses  82  may be between 2-4 inches in diameter, and flexible hoses  86  may be between about 4-6 inches in diameter. Flexible hoses  86  may deliver the collected dust and fumes to ventilator  92  via ventilator inlet manifold  90 . 
     As is also illustrated in  FIG. 3 , exhaust system  80  may further include a ventilator inlet manifold  90 , ventilator  92  and ventilator exhaust duct  94 . Ventilator  92  may create a depression within exhaust system  80  such that the air pressure outside inlet manifold  62  and secondary inlet hoses  82  is greater than the air pressure within exhaust system  80 . Consequently, dust and polluted air generated from the operation of milling system  30  and at weldment  48  may be drawn in and routed through exhaust system  80  to secondary conveyor  50  within secondary conveyor housing  52 . Ventilator exhaust duct  94  may provide a channel whereby the polluted air may enter into secondary conveyor housing  52  from ventilator  92 . In one exemplary embodiment, ventilator  92  may have a cast aluminum fan wheel disposed within a radial steel fan housing, may be powered by a hydraulic motor, and ventilator exhaust duct  94  may extend about 1,000-1,200 mm along secondary conveyor housing  52  so as to maintain a desired air flow through ventilator  92 . The cut-off of exhaust duct  94  may occur prior to a mid-point or folding-point of secondary conveyor  50  for purposes related to transport and shipping of cold planer  10 . 
     Exhaust system  80  may be removably attached to cold planer  10  at attachment points  71 . In particular, attachments  71  may connect rigid pipes  70  to water tank  26  and ventilator  92  to secondary conveyor housing  52 . As rigid pipes  70  may be removably attached to the exterior of water tank  26 , as opposed to running through water tank  26 , exhaust system  80  may be easily removed from cold planer  10 . Upon removal of exhaust system  80  from cold planer  10 , the insertion points of exhaust system  60  (e.g. where the airway of ventilator  78  may enter into secondary conveyor housing  52 ) may be plugged by any number of various different types of plugs, caps, fillers, fittings or stoppers. 
       FIG. 4  illustrates exhaust system  80  attached to cold planer  10 . As illustrated in  FIG. 4 , ventilator  92  and ventilator exhaust duct  94  are attached to the topside of secondary conveyor housing  52 . Secondary inlet hoses  82  enter transition area  44  upstream of weldment  48  at opposing sides of transition area  44 . Flexible hoses  72 ,  82 , and  86  are not themselves attached directly to cold planer  10 , thereby allowing secondary conveyor  50  to move freely from side to side as well as up and down relative to primary conveyor  50  and frame  12 . 
     INDUSTRIAL APPLICABILITY 
     The disclosed exhaust systems may be used with any road material or asphalt removal system where control of milling-generated dust and fumes is desired. The disclosed exhaust systems may help to prevent the egress of dust and fumes from cold planer  10  by routing the dust and fumes to secondary conveyor  50 , from which they can be off-loaded along with the milled asphalt at secondary conveyor discharge end  51 . The operation of exhaust systems  60  and  80  will now be explained. 
     As illustrated in  FIG. 1 , cold planer  10  may break-up and remove asphalt with milling drum  32 . During the operation of milling system  30 , water nozzle  36  may spray water from water tank  26  onto milling drum  32  so as to cool milling drum  32  and its associated cutting tools  34 . In addition to cooling milling system  30 , the sprayed water from water nozzle  36  may also help control dust and fumes that may be generated as a byproduct of the milling process. The water may coalesce the dust particles and fumes with the milled material. 
     As milling drum  32  rotates towards primary conveyor  42 , cutting tools  34  may heap the wet milled asphalt onto primary conveyor  42 . The milled asphalt on primary conveyor  42  may then be transported to and thrust against weldment  48  of transition area  44 . As the milled asphalt strikes weldment  48 , it may break down further and fall onto secondary conveyor  50 . Secondary conveyor  50  may transport the milled material to secondary conveyor discharge end  51 , where the milled material may be off-loaded to transport vehicle  58 . 
     Although water distributed via water nozzle  36  may help to control the amount of dust and fumes generated during the operation of cold planer  10 , a significant amount of dust and fumes may still result. In particular, the operation of milling drum  32  and the crashing of the milled asphalt into weldment  48  are two operations of cold planer  10  that may result in significant amounts of dust and fumes despite the addition of water. Exhaust systems  60  and  80  may further assist in the control of dust and fumes generated during the operation of cold planer  10 . 
     Ventilators  78  and  92  may create a depressed air pressure state within exhaust systems  60  and  80 , such that polluted air may be drawn into inlet manifold  62 , inlet extensions  66  and secondary inlet hoses  82  and routed to secondary conveyor housing  52 . Secondary conveyor  50  may be housed by secondary conveyor housing  52  in such a way so as to prevent the egress of collected dust and fumes prior to the discharge of the same along with the milled asphalt at secondary conveyor discharge end  51 . The length of secondary conveyor  50  and secondary conveyor housing  52  may provide ample time for the collected dust and fumes delivered by ventilator  78  to settle and coalesce into the wet milled asphalt being transported on secondary conveyor  50 . Consequently, the dust and fumes collected by exhaust systems  60  and  80  may be discharged along with the milled asphalt material at secondary conveyor discharge end  51 . 
     With the disclosed placement of inlet manifold  62 , it may be more likely that dust and fumes generated at milling drum  32  are drawn into inlet manifold  62  rather than significantly larger fragments of milled asphalt. If larger fragments of milled asphalt were drawn into inlet manifold  62  and routed through exhaust system  60 , such may incur damage to ventilator  78 . 
     With the disclosed placement of inlet extensions  66 , it may be more likely that dust and fumes generated at milling drum  32 , that escape inlet manifold  62 , may be drawn into inlet extensions  66 . In this way, visibility of road surface  11  at the point of milling may be more closely and accurately monitored. 
     With the disclosed placement of secondary inlet hoses  82 , it may be more likely that excess dust and fumes generated at weldment  48  are captured and routed to secondary conveyor housing  52 . Consequently, visibility and working conditions at or near operator station  20  may be improved. 
     Given its simple design and constitution, exhaust systems  60  and  80  may be easily attached to many different types and models of cold planer  10 . As rigid pipes  70  may be removably attached to the exterior of water tank  26 , as opposed to running through water tank  26 , exhaust systems  60  and  80  may be easily attached to or removed from cold planer  10 . Specifically, older machines may be retrofitted with exhaust systems  60  or  80  if the exhaust-related benefits of such are desired. Regulatory standards may require that an older or current model of cold planer  10  be retrofitted with a system such as either exhaust system  60  or  80 . 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed exhaust systems without departing from the scope of the disclosure. Other embodiments of the exhaust systems will be apparent to those skilled in the art from consideration of the specification and practice of the exhaust systems disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.