It then travels across a belt weigh scale. The belt scale provides soil feed rate and totalized weights to the unit's control system. The feed belt feeds the contaminated soil into a stainless steel counter flow rotary drum desorber. The primary thermal treatment component of the SPI remediation unit is an 8'x32' counter-current rotary drum stainless steel desorber with stainless steel internal flights. Soil is fed into the rotary desorber where the internal flights lift and veil the soil through the hot gas stream produced by the direct-fired primary burner.
Soil flows counter-currently to the airflow in the desorber.
The burner is located on the soil discharge end of the desorber. F depending on engineering specifications and regulatory objectives. Soil residence time in the rotary drum desorber is a function of the desorber rotation speed and depth of fill desired in the system. At a feed rate of 35 tons per hour, the soil residence time will be approximately 7 to 10 minutes. Primary Fuel System Heated air is supplied to the rotary desorber through a propane or natural gas fired burner.