GB780981A - Improvements in or relating to the dry cleaning of garments and other articles - Google Patents

Abstract

<PICT:0780981/III/1> <PICT:0780981/III/2> Articles are dry-cleaned in a closed container by saturating them with an organic solvent, then supplying to the container an aqueous detergent emulsion, measuring the relative humidity of the vapour in the container and cutting off the supply of detergent emulsion thereto when the relative humidity of the vapour reaches a predetermined value. The container is then flushed with further organic solvent, drained, and the articles are finally dried. In a suitable plant, the articles are immersed in a solvent in a drum 1, provided with a rotary cage or tines if desired, the solvent being supplied through a line 2 and being re-circulated by a pump 3 for flushing when desired. The detergent emulsion is supplied to the drum from a tank 6 through line 7, valve 8 and an injector 9 mounted on the drum. Compressed air is supplied through line 11 and valve 12 to the injector 9. The valves 8 and 12 are balanced-pressure valves controlled by electro-magnetic devices which are energized to open the valves by a humidity control device 23. The injector 9 comprises a loaded piston valve with a detergent inlet 16, Fig. 2, a compressed air inlet 17, a spray nozzle 18 and a piston 19 with a conical valve 18b sliding therein and urged into the closed position by a spring 20. In the closed position, the air raises the piston to open the detergent inlet 16, the detergent being thus sprayed by the compressed air through the nozzle 18 into the drum. The humidity-control device 23 open to the drum consists of a hygrometer having a vellum strip which alters its length according to the relative humidity of the vapour in the drum. The vellum strip is connected to a contact close to a second contact, the contacts making electric contact to complete an electric circuit when the strip shortens in a dry atmosphere and separating when the strip lengthens in a moist atmosphere. The hygrometer can be set to open the contacts at a selected relative humidity. A time switch 28 can be set to open and close the hygrometer circuit for set time periods. The hygrometer 23 and switch 28 are connected to a mains circuit including current supply conduits 31 and a relay switch 32 connected to the energizing coils of the valves 8 and 12 respectively. In a modification, the vellum strip may be coupled to a pneumatic control device connected to pneumatic valve-operating mechanism.