METHOD AND PLANT FOR DEPOLYMERIZATION OF SOLIDIFIED POLYMER MATERIALS Russian patent published in 1996 - IPC

FIELD: utilization of wastes. SUBSTANCE: invention relates to reprocessing of thermosetting polymers and decomposition of electroinsulating materials based on epoxide resins. Solidified polymer materials are treated at 170-220 C with aqueous carbon dioxide solution and heated in a closed circuit. To this some water is injected to form mixture of air with live steam under 2-3 atm pressure followed by introducing into the closed circuit compressed or liquid carbon dioxide to pressure 4-6 atm. In the claimed method, polymer material is preheated with hot air and then with steam under pressure 2-3 atm, and depolymerization process is carried out by way of repeatedly passing through sealed circuit a working medium having specified make-up, temperature, and pressure. Depolymerization comprises a main and an additional operational vessels installed in parallel to each other, source of working medium, means for heating the plant, arrangement for forcibly feeding the working medium, arrangement for feeding water and carbon dioxide to form steam-gas-air mixture, and arrangement for capturing decomposition products. All arrangements are interconnected to form the above said sealed circuit also including means for heating plant and working vessels. There is also by-pass region provided with means for its independent switch on and off. Working vessels, also having such a means, are provided with removable flanges, pans, and stainless steel crate to receive polymer material either in the form of lump or in fluid state. Plant is provided with controlling instruments. EFFECT: improved process and design of plant. 9 cl, 3 dwg