Patent · US Expired

Microwave method and apparatus for heating loose paving materials

US4619550A · kind A · utility

47Cited by
14References
24Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 5, 1984
Grant dateOct 28, 1986
Priority date
Expiry dateOct 5, 2004

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE01C2019/1095
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

Fragmented old asphaltic concrete or the like is recycled into new hot-mix by temporarily separating larger pieces from the smaller fragments, generating heat internally within the large pieces with penetrating microwave energy, separately heating the smaller fragments by exposure to hot gas, and then recombining and remixing the separately heated components. The old concrete can be heated very rapidly, highly uniformly and economically while avoiding asphalt degradation and pollution problems that can be caused by exposure to extreme high temperature and while avoiding the relatively high costs of heating the entire volume with microwave energy. Sorting, heating and mixing apparatus (11, 11a) embodying the invention may be made transportable to a site at or near a repaving operation or may be travelable along a roadbed to pick up old concrete and deposit new hot-mix or may be integrated into a fixed hot-mix plant (73, 73a, 73b) to enable, among other modes of operation, production of hot-mix wholly from old reclaimed concrete or production of hot-mix from both old and new materials in any desired proportions.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.