| 摘要 |
#CMT# #/CMT# A method for regenerating hydrophobic pumice used for the recovery of hydrocarbons floating on water with the aid of a vibrating helical elevator for transporting and heating the pumice, involves (1) heating to the desorption temperature (possibly after a preheating phase), (2) a reaction phase in which the volatiles are vaporised, collected by an aspiration system and recovered by condensation and (3) cooling before removing the regenerated product ready for using again. #CMT#USE : #/CMT# For recycling pumice used for the recovery of hydrocarbons floating on water, i.e. for the decontamination of oil-polluted water. #CMT#ADVANTAGE : #/CMT# Enables the regeneration of oil-loaded pumice without destroying the carbon deposit formed during the production of the hydrophobic pumice itself (unlike prior-art calcination methods). The material previously absorbed by the pumice can also be recovered and used for making more oil-absorbent pumice. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a system according to the invention for regenerating pumice used for recovering hydrocarbons floating on water. 1 : heating phase 2 : reaction phase 3 : cooling phase 4 : coil 5 : central barrel 6 : post 7 : vibration motors. #CMT#ENVIRONMENT : #/CMT# Preferred Method: All the operations are carried out in succession in a coil (4) supported on a central barrel (5) fixed onto a post (6), the product being advanced along the coil by means of unbalance motors (7). A partial vacuum may be applied so as to lower the temperature of evaporation, and the heat of condensation may be used to preheat the pumice at the elevator inlet and thus to improve the overall energy efficiency. #CMT#EXAMPLE : #/CMT# The system was tested with 10 l pumice which was regenerated between successive passages of a mixture of 10% waste motor oil and 90% gas oil, using a vibrating helical elevator for heating and moving the pumice. After 10 passes, the volume of pumice was reduced from 10 l to 3.72 l and the volume of oil absorbed was reduced from 2.5 l to 0.82 l, i.e. the percentage absorption changed from 25.00% to 22.04%, with intermediate passage values ranging from 19.18% to 30.00%. |
