This invention relates to improvements to a transportable hydrocarbon-recovery unit. More particularly, this invention relates to an integral hydrocarbon-recovery unit that comprises a first evaporation system and a condensation system. The actual first evaporation system comprises means for supplying the material to be extracted that includes means for controlling supply, means for conveying said material, treatment-chamber means including internal cleaning means, means for heating the material, means for increasing the heat-transfer area, means for removing excess material, including means for increasing hermeticity, and means for conveying the extracted vapors towards the condensation system. The purpose of the invention is to provide a unit for extracting hydrocarbons and other contaminants from impregnated material at the same time as providing, over a shorter time period and with greater effectiveness, the recovery process.