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.-. � DOUBLE BARRE ° G R E E N The benefits of warm mix asphalt such as reduced energy consumption, (owered emissions, and elimi- nation of visible smoke are well-known in the hot mix industry. Warm mix technology allows mix to be pre- pared and placed at lower temperatures, typically 50°F to 100°F lower, than conventional hot mix. To achieve this, the viscosity of the asphalt cement (AC) must re- main free flowing (low viscosity) at the reduced tempera- tures. Maintaining a low viscosity at lower temperatures allows mix to flow freely through storage, transfer and placement equipment and also is more easily worked by hand. Unfortunately, all of the previous technologies for warm mix production rely on additives, special asphalt cement, _ special procedures and/or special AC delivery systems to achieve low viscosities at low - temperatures. The additives °° �' : are expensive and add signifi- � cant cost per ton of mix. The 1 "Astec Multi-nozzle Device" � eliminates the need for ex- - �� pensive additives and special asphalt cement by mixing a ,�„ � �, ��,;� small amount of water and AC . �.., � �,�� ,�, to ether to create microscopic bu�bles. These small bubbles act to reduce the viscosity of the AC coating on the rock thereby allowing the mix to be handled and worked at lower temperature. Each nozzle is capable of passing AC and producing foam for 50 tph of production. The 10 production valve- assemblies in the multi-nozzle arrangement are capable of passing AC and producing foam for production rates up to 500 tph when all valves are opened. As produc- tion rate varies, a computer control opens and closes these AC solenoid valves so that each valve assembly and nozzle operates in a narrow range of AC flow and back pressure to achieve consistent foaming in the foam- ing chamber. In addition to the 10 valve assemblies used for production, an eleventh valve (not shown) is located on the manifold for retrieving AC samples. --°�- +�E . . Improved Workablilty SYSTEM � • No Smoke - No Smell • High Percentage Recycle Mix with Standard Grade of Asphalt • Longer Life Pavement • 14% Less Fuel • 14% Higher Production Water is delivered to the system via a positive displace- ment piston pump capable of delivering water at pres- sures in excess of 150 psig. Water pump speed is modu- lated proportionally to the speed of the liquid AC pump to accurately meter water into the AC valve-nozzle as- semblies. Individually controlled water solenoid valves control the flow of water into each nozzle for each nozzle assembly so that water solenoid valves open at the same time each of the AC solenoid valves open. PLC control provides for smooth and consistent operation of all of the valves as production rates increase or decrease. Water is supplied to the system via a skid-mounted 550-gallon corrosion-free water reservoir with an automatic filling valve that will keep the container full as long as water is supplied to it. If supply water is (ost, a low-water alarm alerts plant personnel quickly so the problem may be re- solved quickly without wasting mix. .� Multi-Nozzle Device Water � � _ ti,�� /Manifold Water .' Lines � - - AC �, . --:_ � r �Manifold r ;( , _ _z .� � � .. ��. � � � A ' � ,_ Foam i ' ManiFold r � �' � + - _ j i'�d" �� . . . +� i": ( _ � -. ii�� -� `F � : �- �„ _ ; � , �� , �« � , �--.,,,.., . r , � r `ia�,-. �. � � y _ �J � . � 0 � a � t�ARF�EL� � ��,,. � - - � i J i... -�1 � .� �:,:� � � �� . .i �