Our Technology

About RAP Technology
Variable speed AC drive motors control raw material feed rates to produce a consistent mix day after day. An insulated direct fired rotary dryer dries and heat RAP fractions to typical paving temperature. Standard spin stabilized burners add the heat and can to burn any commercial fuel: oil, natural gas, or propane.  RAP Technologies provides the only 100% RAP solution that directly heats the asphalt millings. While other companies have created complex plants to avoid direct heating, we use simple, conventional methods to heat the RAP and treat the blue smoke with our patented Pollution Control Device.

Pollution Control

Today, environmental controls are a critical component of any manufacturing process.  For 100% RAP mix, your primary concern will be controlling blue smoke and hydrocarbon emissions.  Every 100% recycle technology takes a unique approach to controlling dryer emissions.  We use a patented three-stage collector based on standard elements to remove blue smoke and hydrocarbons emissions from the RAP dryer’s exhaust.

Pollution Control

Inertial Primary Collector

RAP’s stone dust is encapsulated by asphalt binder and is not prone to become airborne during drying.  Dust that’s carried out of the dryer is plus 325 mesh making it easy to filter.  An inertial separator drops out a wheelbarrow of the heaviest fines every week or so.  Doing a good job fractionating your RAP will reduce the amount of fines collected by minimizing RAP sand carryover into the stone fraction.

 
 

Disposable Secondary Collector

A second stage of disposable fiberglass filter fabric removes micron size particles. Laminated non-woven media is indexed as pressure drop increases due to captured pollutants.  Spent media is disposed of since enough oil is captured to make cleaning impractical.

Disposable Secondary Collector

Fiber-Bed Filter Tertiary Control

Exhaust gases pass through densely packed beds of generic glass insulation to remove soluble particulate matter (PM) and liquid aerosols, including volatile organic compounds (VOC) by inertial and Brownian interception.  Control efficiency is improved by adiabatic cooling prior to filtration to condense vapors and increase the size of aerosol droplets.  This zone must be operated at 160 to 180 degrees Fahrenheit to maximize life of the filter media. Fiber-bed filters are ideal since they can handle mists and saturated exhaust streams with relatively low-pressure drop.

Air Permits

Permit requirements vary from state to state.  Generally in the mid-Atlantic region with non-attainment status for ground level ozone, permits could be limited to 70,000 tons per year to avoid triggering a more rigorous state of the art performance standards.

PM 0.02 Grains
CO 0.2 1 lb/ton
VOC 0.14
NOx 0.08
S02 0.06