POLLUTION-FREE ASPHALT PLANT

THIS COMPACT PLANT (OCCUPYING AN AREA OF ONLY 66 SQUARE METERS) CONSISTS OF A COLD FEED ELEVATOR, BATCH WEIGH HOP- PER, MIXING BARREL, AND AIR HEATER. A BATCH OF GRADED AGGREGATE IS FED INTO THE BATCH WEIGH HOPPER, WHERE ADDITIONAL WATER CAN BE ADDED TO BRING IT TO AN OPTIMUM MOISTURE CONTENT OF 2-3 PERCENT. THE AGGREGATE IS THEN DIS- CHARGED INTO THE REVOLVING BARREL WHERE THE HOT BITUMEM IS ADDED AS A SPRAY. A FEW REVOLUTIONS OF THE BARREL DISPERSES THE BITUMEN AMONG THE DAMP AGGREGATE. THE BURNERS ON THE HOT AIR DRUM ARE THEN IGNITED AND THE HOT AIR TEMPERATURE (650 DEGREES C) IS DRAWN THROUGH THE MIXING BARREL BY A CENTRIFUGAL MAIN FAN. VACUUM IMPREGNATION (WHICH IMPROVES ADHESION BETWEEN BITUMEN AND STONE) TAKES PLACE WHEN THE BITUMEN FLOWS INTO THE VOIDS VACATED BY THE WATER - A PROCESS AIDED BY THE CONSIDERABLE BUBBLING WHICH TAKES PLACE. AFTER THE TIME PRESCRIBED FOR THE TYPE OF MIX, THE SPEED OF THE REVOLVING BARREL IS TILTED BACK AND THE MIX IS DISCHARGED INTO A TRUCK. ALL THE FINES REMAIN IN THE MIX, AND THE AIR STREAM FROM THE EXHAUST STACK IS COMPLETELY FREE FROM DUST. FLUXED BITUMEN BINDERS MAY BE USED BY ADOPTING A SLIGHTLY MODIFIED PROCEDURE. THE ADVANTAGES OF THIS METHOD ARE LISTED. THESE INCLUDE LOW MAINTENANCE COSTS AND GOOD MOBILITY, ELIMINATION OF THE NEED FOR COVERED STOCKPILES AND THE ELIMINATION OF DUST, DIRECT AND PRECISE TEMPERATURE CONTROL ACHIEVED THROUGH USING INFRA-RED PYROMETER CONTROLS, ELIMINATION OF THE NEED FOR WATER QUENCHING AND ENABLING THE DELIVERY OF COATED CHIPPS DIRECT FROM THE PLANT. THE PLANT CAN ALSO BE USED FOR THE PRODUCTION OF CEMENT-BOUND MIXES AND CONCRETE.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00373516
• Corporate Authors:

  Shell International Petroleum Company Limited

  Shell Center
  London SE1 7NA,   England 
• Publication Date: 1973

Media Info

• Features: Figures; Photos;
• Pagination: p. 6
• Serial:
  • Shell Bitumen Review
  • Issue Number: 41
  • Publisher: Shell International Petroleum Company Limited
  • ISSN: 0037-3516

Subject/Index Terms

• TRT Terms: Aggregates; Bitumen; Cement; Concrete plants; Control; Economic benefits; Infrared radiation; Maintenance management; Mixing plants; Pollution; Stockpiling; Temperature control (Structures)
• Uncontrolled Terms: Maintenance costs
• Old TRIS Terms: Bituminous mixing plants
• Subject Areas: Economics; Environment; Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00211803
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 5 2003 12:00AM