Ing. Mlčoch Petr, Ing. Hermann Radek, Ing. Tacina Marek, Ing. Lasota Libor, Ing. Raclavský Milan
TŘINECKÉ ŽELEZÁRNY, a.s.
Patent 304 773 a EP28629 48
The proposed method of removing oil and oil products from materials contaminated thereby, particularly from metal-bearing waste arising in the production and treatment of metals, is characterized by refining of the contaminated materials by their indirect heating within an enclosed furnace space to a temperature in the range of 250 to 750 degC. At the same time, the enclosed furnace space is purged by a protective atmosphere containing at the most 15 percent by volume of oxygen whereupon the mixture of gases and steam generated by evaporation and decomposition of the present oil and oil products from the contaminated materials, is withdrawn from the enclosed furnace space, subjected to cooling and condensation. During refining, the materials contaminated by the oil and oil products, are agitated and after achieving a final temperature of heating and finish of the refining process, they are cooled down by spraying water in an amount up to 300 l per 1000 kg of the material being treated. At the same time, the non-condensed portion of the mixture of the generated gases and steam is withdrawn for further processing and/or is controllably returned as process gases back to the refining process. Apparatus for making the above-described method consists of a refining furnace provided with a heat source of indirect heating of the furnace space and with a charging inlet of contaminated materials, as well as with a discharge outlet of purified materials. The refining furnace is further provided with a charge agitation device arranged within the furnace space, as well as with a supply inlet of inert gas from a pressure source and a discharge piping of a mixture of gases and steam, generated by evaporation and decomposition of liquids in the charge, to a condenser with a branched outlet of the separated condensation products.