Unit for dry cleaning textile articles using a composite solvent and for recycling the used composite solvent for re-use

Abstract

The invention relates to a unit for dry cleaning textile articles using a composite solvent comprising multiple components, said unit including: a dry cleaning chamber ( 1 ) configured to mix the textile articles to be cleaned with the composite solvent during a cleaning cycle; a device ( 7 ) for recovering the used composite solvent after a cleaning cycle; a treatment device ( 8 ) for removing water and dirt and recycling at least part of the used composite solvent in order to use same in another dry cleaning cycle. The unit is characterised in that it also comprises a re-adjustment device ( 9 ) for re-adjusting the composition of the recycled composite solvent, incorporating therein at least the part of the component(s) that was lost in the treatment device ( 8 ), said re-adjustment device comprising at least: a buffer tank ( 10 ) provided with at least one supply inlet ( 10 a ) for the recycled composite solvent, at least one supply inlet ( 10 b ) for at least the part of the component(s) of the composite solvent to be introduced into the buffer tank ( 10 ) in order to re-adjust the composition of the recycled composite solvent, and at least one outlet ( 10 c ) for the re-adjusted and recycled composite solvent, said outlet ( 10 c ) being connected to the storage tank ( 5 ) for the dry cleaning composite solvent; a storage tank ( 11 ) for one or more components of the dry cleaning composite solvent; and a metering pump ( 14 ) for metering the quantity of the component(s) of the composite solvent to be introduced into the buffer tank ( 10 ) through the inlet ( 10 b ) in order to re-adjust the composition of the recycled composite solvent, said pump being linked upstream to at least one storage tank ( 11 ) containing one or more components of the dry cleaning composite solvent.

1 . A Unit for dry cleaning of textile articles using a composite solvent comprising several components comprising:
 a dry cleaning chamber ( 1 ) configured to mix, during a cleaning cycle, textile articles to be cleaned with a composite solvent;   a device ( 7 ) for recovering the composite solvent after the cleaning cycle;   a treatment device ( 8 ) for removing water and dirt and recycling at least a portion of the composite solvent for the purpose of using the recycled composite solvent for another dry cleaning cycle,   a re-adjustment device ( 9 ) for re-adjusting the recycled composite solvent by incorporating therein at least a portion of the component or components that was lost in the treatment device ( 8 ), wherein the device comprises at least:   a buffer tank ( 10 ) provided with at least one supply inlet ( 10   a ) for the recycled composite solvent, with at least one inlet ( 10   b ) for the supply of at least the portion of the component or components of the composite solvent to be introduced into said buffer tank ( 10 ) in order to re-adjust the composition of the recycled composite solvent, and with at least one outlet ( 10   c ) for the recycled and re-adjusted composite solvent, with this outlet ( 10   c ) being connected to the storage tank ( 5 ) for the dry cleaning composite solvent,   a storage tank ( 11 ) for one or several components of the dry cleaning composite solvent, and   a metering pump ( 14 ) of the quantity of the component or components of the composite solvent to be introduced into the buffer tank ( 10 ) through said inlet ( 10   b ) for the re-adjustment of the composition of the recycled composite solvent, this pump is connected upstream to at least one storage tank ( 11 ) containing one or several components of the dry cleaning composite solvent.   
     
     
         2 . The Unit according to  claim 1 , wherein the re-adjustment device ( 9 ) is provided with an analyzer ( 15 ) which makes it possible to analyze the physical and/or chemical characteristics of the recycled composite solvent, to determine the quantity of the component or components of the composite solvent to be taken from the storage tank ( 11 ) and to be introduced into the buffer tank ( 10 ). 
     
     
         3 . The Unit according to  claim 1 , wherein the cleaning chamber ( 1 ) is provided with a perforated drum ( 2 ) intended to receive the textile articles to be cleaned, said perforated drum ( 2 ) being mounted rotatingly in said chamber, with the latter having:
 an opening ( 20 ) for the placing of textile articles to be dry cleaned in the perforated drum ( 2 ), with this opening able to be closed by a door or a porthole;   an orifice ( 3 ) connected to a duct for introducing ( 4 ) the composite solvent which is placed in a storage tank ( 5 ); and   an orifice ( 6 ) connected to the recovery device ( 7 ).   
     
     
         4 . The Unit according to  claim 1  wherein the device ( 8 ) for treating the used composite solvent comprises at least one filtration device ( 12 ) for filtering insoluble dirt contained in said used composite solvent and a fractionated distillation unit ( 13 ) comprises:
 an outlet for the removal of a top fraction F1 representing less than 15% w/w used composite solvent  and containing at least water, one or several azeotropes formed between the water and one or several components of the composite solvent; and 
 an outlet for the recycling of an intermediate fraction F2 representing more than 75% w/w used composite solvent  and containing the dry cleaning composite solvent less at least one portion, by weight, of one or of several of its components, said intermediate fraction F2 being directed after recycling to the buffer tank ( 10 ). 
 
     
     
         5 . The Unit according to  claim 4 , wherein the fractionated distillation unit ( 13 ) is provided with a collection container ( 31 ) configured to receive in a first step the top fraction F1 before it is discharged to the removal tank ( 30 ), then in a second step, the intermediate fraction F2 before it is sent to the buffer tank ( 10 ), said collection container ( 31 ) having a drawing-off point ( 31   a ) in its lower portion, through which the top fraction F1 and the intermediate fraction F2 are removed to their respective tanks ( 30 ) and ( 10 ); and being provided with an analyzer ( 15   a ) making it possible to analyze the physical and/or chemical characteristics of the top fraction F1 or of the fraction F2 in such a way as to determine the quantity of the component or components of the composite solvent to be introduced into said buffer tank ( 10 ). 
     
     
         6 . The Unit according to  claim 5 , wherein the removal tank ( 30 ) intended to contain the top fraction F1, comprises a duct ( 300 ) connected to an injection device ( 301 ) making it possible to inject, after N dry cleaning cycles, said fraction F1 into the fractionated distillation unit ( 13 ) for the purpose of separating it into at least two fractions: one top fraction F′ 1 intended to be removed, and a fraction F2 intended to be added, before the re-adjusting of the recycled composite solvent, to the intermediate fraction F2 collected after the cycle N of dry cleaning. 
     
     
         7 . The unit according to  claim 1 , wherein the composite solvent comprises at least:
 40% to 80% w/w dipropylene glycol monomethyl ether,   5% to 40% w/w an amphiphilic solvent A having the following formula: R—(O—C 3 H 6 ) n —OH (1) wherein n is an integer equal to 1 or 2, and R a C 3 - or C 4 -alkyl group,   10% to 40% w/w a dibasic ester B selected from the group comprising dimethyl succinate, dimethyl glutarate, dimethyl adipate and mixtures thereof, and   0% to 10% w/w additional components.   
     
     
         8 . A method of dry cleaning of textile articles with a composite solvent having a plurality of components and of recycling the used composite solvent for reuse, said method comprising:
 a) a dry cleaning cycle comprising contacting fabric articles to be cleaned with the composite solvent,   b) recovering the used composite solvent contaminated with dirt and water at the end of the dry cleaning cycle,   c) treating the used composite solvent in order to remove at least water and dirt, and   d) recycling at least a portion of the composite solvent treated in step c) for the purpose of using it for another dry cleaning cycle,   wherein the composition of the recycled composite solvent is readjusted by incorporating at least the portion, by weight, of the component or the components of the composite solvent, which portion was lost during the treatment step aimed at removing the water and dirt.   
     
     
         9 . The method according to  claim 8 , wherein the portion, by weight, to be incorporated in the composition of the recycled composite solvent is determined from the physical and/or chemical analysis of the recycled composite solvent. 
     
     
         10 . The method according to  claim 8 , wherein the treatment step aimed at removing the water and dirt comprises a fractional distillation. 
     
     
         11 . The method according to  claim 10 , wherein the fractional distillation is conducted so as:
 to remove a top fraction F1 comprising less than 15% w/w used composite solvent and containing at least water and one or several azeotropes formed between water and one or more components of the composite solvent, and   to collect an intermediate fraction F2 representing more than 75% w/w used composite solvent containing the dry cleaning composite solvent less at least a portion, by weight, of one or more of its components, which portion was lost in the treatment comprising the fractional distillation.   
     
     
         12 . The method according to  claim 11 , wherein the top fraction F1 removed by fractional distillation in step c) is distilled at a temperature less than 82° C. and a pressure of 65 bars and comprises at least water, dipropylene glycol monomethyl ether, and optionally an amphiphilic solvent A′ having the following formula: R′-0-C 3 H 6 —OH (I′) wherein R′ represents a C 3 - or C 4 -alkyl group. 
     
     
         13 . The method according to  claim 11 , wherein the intermediate fraction F2 recovered by fractional distillation in step c) distills at a temperature above 83° C. and under a pressure of 65 bars. 
     
     
         14 . The method according to  claim 7 , wherein the portion to be incorporated into the composition of the recycled composite solvent comprises at least dipropylene glycol monomethyl ether, and optionally an amphiphilic solvent A′ of formula R′—0-C 3 H 6 —OH (I′) wherein R′ represents an C 3 - or C 4 -alkyl group. 
     
     
         15 . The method according to  claim 13 , wherein the top fraction F1 removed in step c) is recovered in a drain tank, then, after N dry cleaning cycles, is subjected to a fractional distillation, which fractional distillation is conducted so as to remove a top fraction F1, said top fraction F1 containing a major amount of water, and to recover a fraction F2, said fraction F′2 being intended to be added, before step e) of readjustment, to the intermediate fraction F2 recovered after the N dry cleaning cycle.