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The automatic degreasing machines, fed by
chlorinated solvents, have a recycling cycle of the utilised solvents, by means of an
atmospheric pressure distiller which operates in a continuous cycle.In the process
residues, formed by oil, grease, metals, etc. the solvents are still present in a
percentage of between 20 and 50%. In the distillation residues, composed of oil, grease, metals etc., the solvents are still present approximately from 20 to 50%. This high percentage is due to the thermolability of the chlorinated solvents, not allowing a forced distillation which can cause their acidification. This has two consequences : a waste of solvent and a high disposal cost of the residue, which contains a high percentage of solvent.A notable improvement is achieved by vacuum distillation, which enables to lower this percentage to between 5 and 8%. The definitive solution of this problem is obtained by combining vacuum with azeotropic distillation |
AZEOTROPIC VACUUM DISTILLATION |
In large petrochemical plant, azeotropic vacuum distillation has been used for many years and it is still one of the most common processes to treat thermolable solvents, not mixable in water, polluted by liquid contaminants. FORMECO has transferred this sophisticated technology on to small size units.The process consists of a "soft" vacuum distillation for about 70-80% of the polluted solvent. Later on, the concentrated residues present inside the boiler, will be treated by a flow of steam which strips the residue part of solvent still present, at a working temperature more than 20% under the critical one which causes acidification. |
RESULTS |
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THE UNITS |
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OPTIONAL |
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