Asphalt shingle recycling system and method

Abstract

A method of recycling asphalt roofing material is provided. The asphalt roofing material is delivered into a treatment chamber of a processor. A heat source is provided to the treatment chamber. Heat energy is transferred from the heat source to the asphalt roofing material to produce a heated product, and the heated product is removed from the treatment chamber.

Description

RELATED APPLICATIONS[0001]This application claims the benefit, and priority benefit, of U.S. Patent Application Ser. No. 61 / 069,435, filed Mar. 14, 2008, titled “Asphalt Shingle Recycling System and Method.”BACKGROUND[0002]1. Field of Invention[0003]The invention relates generally to recycling of asphalt shingles, and in particular, to a system and method for recycling of asphalt shingles utilizing heat treatment.[0004]2. Description of the Related Art[0005]Asphalt concrete pavement is commonly used in roadway construction. The asphalt concrete pavement typically comprises liquid asphalt cement combined with aggregate. The aggregate is usually a mixture of sand, gravel, and stone. The aggregate and liquid asphalt cement are mixed and heated to form an asphalt paving composition. The crushed gravel and stone particles of the aggregate provide sharp edges which, when combined with the liquid asphalt cement, create an aggregate interlock which improves the strength of the composition.[...

AI Technical Summary

Benefits of technology

[0008]In accordance with the illustrative embodiments hereinafter described, a system and method for recycling asphalt roofing shingles is described. In an embodiment, scrap and tear-off shingles from roofing materials are heat treated and liquefied to produce a slurry that can be formed into a finished product. The composition of the slurry can be regulated with a relatively high degree of consistency. Further, many of the air emissions concerns that existed in previous asphalt shingle recycling processes are eliminated.

[0011]In another illustrative embodiment, an apparatus for recycling asphalt roofing material is provided. The apparatus can include a jacketed agitated processor for heating the asphalt roofing material to produce a partially liquefied product, a heating skid for supplying a heat source to the jacket of the agitated processor, and a hammer mill for reducing the particle size of solid particles present in the partially liquefied product. The apparatus can also include a sizing unit for reducing the particle size of solid particles present in the partially liquefied product before the partially liquefied product is delivered to the hammer mill. A screw conveyer can be utilized for delivering asphalt roofing material to the processor. The screw conveyer can include a plurality of variable speed conveyors for regulating the flow of untreated asphalt roofing material to the treatment chamber. One or more temperature measuring devices can be disposed at the outlet of the jacketed agitated processor. Further, one or more cooling devices can be positioned between the outlet of the jacketed agitated processor and the inlet of the hammer mill for measuring and regulating temperature at the processor outlet.

Problems solved by technology

Liquid asphalt cement can be expensive.

It is difficult to regulate the consistency of the asphalt pavement composition using shredded asphalt roofing shingles produced by existing recycling processes.

Also, air emissions from existing recycling processes can be detrimental to the atmosphere.

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