The process is to rapidly volatilize the petroleum hydrocarbons present in the soil while maintaining a feed rate of 75 tons per hour. The hot soil is then discharged from the dryer into a proprietary conditioning system called a mixer/cooler along with the dust particles in the dryer which may not have had enough heat exposure in the rotary kiln to sufficiently rid them of contaminants; the mixer/cooler cools and remoistens the processed soil/dust mixture so that the end product is able to be handled by loaders and dump trucks. The entire process takes place within an enclosed system of ducts, augers, and conveyors which results in a clean and safe operation while still maintaining a high rate of production.
Realizing that the soils are clean solves half of the remediation problem. The contaminants that were once present in the soil are now volatilized into the gas stream. From here they must be destroyed before entering the exhaust stack and ultimately the atmosphere; to remedy this problem, a thermal oxidizer (after-burner) has been incorporated into the design. The exhaust from the rotary dryer is first drawn through a primary collector which serves to collect a large portion of dust particles which go on to the mixer/cooler for further remediation. From here the gasses pass through the baghouse and then to the thermal oxidizer and exposed to extreme temperatures to sufficiently combust the hydrocarbons contained in the gas stream. The gasses leaving the oxidizer are then virtually void of all contaminants before entering the atmosphere.
The combination of a dedicated feel bin for the soil, the counter flow rotary kiln, the mixer/cooler, and the thermal oxidizer makes this the most technically advanced system for properly remediating large volumes of contaminated soil while complying with all local and federal environmental regulations.
There are no limitations due to soil type and levels of contamination which can be effectively treated thereby producing a recycled product suitable for a variety of uses such as gravel road base, fill material as well as landfill cover.