Process and device for regenerating a contaminated solvent
AssigneeDidda Maria Janina Baumann
InventorWalter Baumann
Life of this patent
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Abstract
Process and apparatus for regenerating a contaminated solvent wherein said solvent is first separated from higher-boiling contaminants in an evaporator, and then contaminants having a lower boiling point than said solvent are separated out in a condenser in which the temperature of said lower-boiling contaminants coming out of said condenser and the temperature of said solvent coming out of said condenser are separately controlled.
Claims15
Apparatus for the recovery of purified solvent from contaminated solvent with separation of contaminants, comprising an evaporator (26) for the separation of contaminants whose boiling point is higher than the boiling point of the purified solvent, and a condenser (40) following the evaporator (26) for the separation of contaminants whose boiling point is lower than the boiling point of the purified solvent, the condenser (40) having an inlet for the vapor coming from the evaporator (26), an outlet for condensed liquid solvent, as well as an outlet for the vaporous contaminants whose boiling point is lower than the boiling point of the pure solvent, a closed, separate cooling circuit from which coolant flows through the condenser (40), the closed cooling circuit having a regulating system (58, 59) which consists of a cooler (58) and a control valve (59) disposed in a bypass to the cooler (58) which valve (59) is operated by the temperature of the vaporous contaminants upon issuing from the condenser (40), thus adjusting the temperature of the coolant upon entry into the condenser (40), which thus serves for adjusting the temperature of the vaporous contaminants issuing from the condenser (40) at the same side of condenser (40) as the coolant of the closed cooling circuit enters the condenser (40), the closed cooling circuit having a circulation pump (60) for regulating the rate of flow of the coolant in the condenser, which thus serves to adjust the temperature of the condensed purified solvent as it leaves the condenser (40) at the same side of condenser (40) as the coolant leaves the condenser (40).
A process for the recovery of purified solvent from a contaminated solvent, which comprises
- a) feeding the contaminated solvent to an evaporator (26) and separating the solvent from the contaminants that have a higher boiling point than the solvent by evaporation in the evaporator, to produce a vapor stream of solvent, which leaves the top of the evaporator, while the higher boiling contaminants remain in the liquid state in the bottom of the evaporator;
- b) feeding the vapor stream to a condenser (40) and condensing the solvent, by partial condensation, while the contaminants which have a lower boiling point than the solvent remain in the vapor state;
- c) removing condensed solvent from the bottom of the condenser as a liquid stream and uncondensed vapor containing the lower-boiling contaminants from the top of the condenser (40) as a vapor stream and,
- d) regulating the temperature of the vapor stream leaving the condenser and the temperature of the condensed solvent liquid stream leaving the condenser independently of each other by means of a closed separate cooling circuit, the coolant of which enters the condenser at the same end that the vapor stream leaves the condenser, and leaves the condenser at the same end as the condensed liquid solvent stream leaves the condenser, by adjusting the temperature of the coolant entering the condenser (40) in accordance with the temperature of the vapor stream leaving the condenser, to maintain the temperature of the vapor stream at a predetermined set point;
- and adjusting the flow rate of the coolant flowing through the condenser (40) in accordance with the temperature of the condensed liquid solvent stream leaving the condenser to maintain the temperature of the condensed liquid solvent stream leaving the condenser at a predetermined set point.
Dependencies are inferred from the claim text.