Recycling
Recycling is synonymous in most production processes and the asphalt manufacturing section is no exception.
The reprocessing of reclaimed asphalt has many advantages, not only beneficial to the national economy but also for the preservation of valuable natural resources.
From the producers viewpoint it is becoming necessary to achieve a more acceptable market price.
 
Cold Processing I
Reclaimed asphalt planings can be added in quantities up to 25 % direct into the paddle mixer where it is homogenously mixed with virgin aggregates.
BENNINGHOVEN supply the complete system necessary for this method consisting of:
• Steep sided Cold feed hopper(s)with oversize grid
• Variable speed belt feeder(s)
• Conveying system by conveyor or elevator
• Dose weighing system
• Flue gas disposal arrangement
• Full electrical integration to the mixing controls

Cold Processing II
A further innovative system is to introduce the reclaimed asphalt planings into the discharge end of the dryer via a “high speed” slinger conveyor to mix with the virgin aggregates. Heat transfer starts to occur in the dryer and flue gases produced pass through the existing system. Heat transfer continues
 

BENNINGHOVEN offer the complete range of technology and equipment to meet customers specific requirements for both hot and cold recycling, including single or double rotor asphalt planings crushers in fixed or mobile configuration.
The equipment is made to the expected BENNINGHOVEN standards and complies with all safety and environmental regulations.
Reclaimed asphalt is reprocessed after it has been reduced to an acceptable size by crushing.
BENNINGHOVEN offer single or double rotor asphalt planings crushers in fixed and mobile configuration.



















      
                               

Diagram illustrating high speed slinger conveyor
the effect of which is to throw larger sized materials further into the dryer cylinder.
Thereby prolonging its retention time within the dryer.

Hot Recycling
For larger quantities of reclaimed asphalt planing processing, up to 100%, hot recycling is necessary.
This is achieved through a separate, uniflow large volume drying drum equipped with a special BENNINGHOVEN developed
burner. The design of the dryer internals preclude direct contact between the flame and reclaimed material.
After heating, the processed asphalt is stored in an insulated buffer silo from where
 it is batch weighed and introduced to the mixer as required.



Combination oil, natural gas and coal burner with frequency inverter control

 
Illustrating frequency inverter control to impellor shaft

Multi fuel burner head designed to burn oil, gas and coal dust

The combustion zone of the hot RAP drum is fitted with special, heavy duty self cleaning "finger" lifters which vibrate during production to prevent clogging of the RAP material during the efficient heating process.
 
 
160 t/h Hot recycling parallel drum system

 
 Hot recycling parallel drum system with a combination burner for oil, coal and natural gas


Material flow diagram of hot recycling drum system including bypass chute for the cold feed into the mixer