Apparatus and method for preparing paving mixtures

Abstract

A paving mixture apparatus broadly comprising a conveyance zone, a vertical transition zone, a spray bar, a filler material feeder, and an agitation zone. The spray bar is configured to deliver a substantially continuous and laminar sheet of liquid mixture in the vertical transition zone. The substantially continuous and laminar sheet of liquid mixture urges aggregate from the conveyance zone and filler material from the filler material feeder downward in the vertical transition zone toward the agitation zone and reduces static electricity buildup in the filler material.

Having thus described various embodiments of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following: 
     
         1 . A paving mixture apparatus for preparing a paving mixture to be applied to a surface, said paving mixture comprising aggregate, water, and an asphalt-containing emulsion, said paving mixture apparatus comprising:
 a conveyance zone for transporting aggregate;   a vertical transition zone defining a transition zone inlet for receiving aggregate from said conveyance zone and a transition zone outlet positioned at a lower elevation than said transition zone inlet;   a spray bar configured to deliver water into said vertical transition zone, said spray bar defining at least one elongated discharge outlet for discharging a substantially continuous sheet of water in said transition zone; and   an agitation zone for mixing an asphalt-containing emulsion with water and aggregate received from the vertical transition zone.   
     
     
         2 . The paving mixture apparatus of  claim 1 , further comprising a filler material feeder for supplying fiber segments to said transition zone, wherein said transition zone defines a filler material inlet for receiving said filler material segments from said filler material feeder. 
     
     
         3 . The paving mixture apparatus of  claim 2 , wherein said filler material inlet and said vertical transition zone inlet are horizontally positioned on generally opposite sides of said sheet of water. 
     
     
         4 . The paving mixture apparatus of  claim 2 , wherein said filler material inlet is configured to direct said filler material segments towards said sheet of water. 
     
     
         5 . The paving mixture apparatus of  claim 4 , wherein said filler material inlet is vertically positioned above said transition zone outlet and below said discharge outlet of said spray bar. 
     
     
         6 . The paving mixture apparatus of  claim 1 , wherein said discharge outlet comprises a single discharge opening having a length-to-thickness ratio of at least 20:1. 
     
     
         7 . The paving mixture apparatus of  claim 1 , wherein said discharge outlet faces generally downward. 
     
     
         8 . The paving mixture apparatus of  claim 7 , wherein said discharge outlet faces in a direction that is angled from vertical by at least 10 degrees and not more than 45 degrees. 
     
     
         9 . The paving mixture apparatus of  claim 1 , wherein said discharge outlet of said spray bar is vertically positioned closer to said transition zone inlet than to said transition zone outlet. 
     
     
         10 . The paving mixture apparatus of  claim 1 , wherein said spray bar defines a water inlet for receiving said water and includes an additive mixer operable to combine at least some of said water and said additive for forming a liquid mixture. 
     
     
         11 . The paving mixture apparatus of  claim 1 , wherein said agitation zone comprises an emulsion inlet for supplying said asphalt-containing emulsion to said agitation zone. 
     
     
         12 . The paving mixture apparatus of  claim 1 , further comprising a spreader box for receiving said paving mixture from said agitation zone and for applying said paving mixture to said surface. 
     
     
         13 . A spray bar for use in a paving mixture apparatus, the spray bar comprising:
 a water inlet plate defining a water inlet for receiving water therethrough;   a water inlet spacer plate defining a flow distribution chamber for horizontally distributing the water;   a flow limiter plate defining a plurality of flow restriction openings for reducing turbulence in the water;   a limiter spacer plate defining at least one flow transition chamber for changing the water flow to a substantially laminar water flow;   a water profile plate defining at least one flow profile opening having a width-to-height ratio of no less than 3:1;   a water outlet spacer plate defining a flow chamber and having a discharge outlet defining a discharge opening having a width-to-thickness ratio of at least 5:1, the flow chamber being configured to develop a substantially continuous sheet of water;   an additive mixer mounting plate defining a secondary water outlet for delivering water therethrough; and   an additive mixer configured to mix additive with the water from the secondary water outlet of the additive mixer mounting plate for forming a liquid mixture.   
     
     
         14 . The spray bar of  claim 13 , wherein the water inlet plate and the additive mixer mounting plate are positioned on opposite sides of the spray bar. 
     
     
         15 . The spray bar of  claim 13 , wherein the limiter spacer plate is positioned between the flow limiter plate and the water profile plate. 
     
     
         16 . The spray bar of  claim 13 , wherein the water inlet spacer plate is adjacent the water inlet plate, the flow limiter plate is adjacent the water inlet spacer plate, the limiter spacer plate is adjacent the flow limiter plate, the water profile plate is adjacent the limiter spacer plate, the water outlet spacer plate is adjacent the water profile plate, and the additive mixer mounting plate is adjacent the water outlet spacer plate. 
     
     
         17 . A method of preparing a paving mixture, said method comprising:
 (a) introducing an aggregate into a vertical transition zone;   (b) introducing a water-containing liquid into said vertical transition zone in the form of a substantially continuous liquid sheet having a width-to-thickness ratio of at least 5:1;   (c) allowing said aggregate and said water-containing liquid to pass downwardly through said vertical transition zone and into an agitation zone; and   (d) mixing said water-containing liquid, said aggregate, and an asphalt-containing emulsion in said agitation zone.   
     
     
         18 . The method of  claim 17 , wherein said liquid sheet has a width-to-thickness ratio of at least 20:1. 
     
     
         19 . The method of  claim 17 , further comprising introducing fiber segments into said vertical transition zone. 
     
     
         20 . The method of  claim 17 , wherein said aggregate is introduced into said vertical transition zone on one side of said liquid sheet and said fiber segments are introduced into said vertical transition zone on an opposite side of said liquid sheet. 
     
     
         21 . The method of  claim 17 , further comprising contacting a substantial portion of said fiber segments with said liquid sheet. 
     
     
         22 . The method of  claim 21 , wherein a substantial portion of said fiber segments become mixed with said water-containing liquid in said vertical transition zone. 
     
     
         23 . The method of  claim 17 , wherein said water-containing liquid comprises water and an additive. 
     
     
         24 . The method of  claim 23 , wherein said additive is mixed with said water below said spray bar.