Dry-cleaning machine with steam heated drying air

Abstract: A dry-cleaning machine for linen and garments which comprises a drum (2) containing the garments and/or linen to be washed, rotating inside a washing tank (1), means for circulating a solvent connected with said tank and including a device (3) for continuously distilling the solvent heated up with the steam produced by means of electric heating (12), and means (6) for circulating drying air including air heating means (19, 15). The drying air heating system comprises a heat exchanger (15) installed upstream from air inlet to said tank and using the steam produced inside said distillation device (3) as a heating medium. This result in a lower installed electric power and considerable energy saving.

Description: The present invention relates to a dry-cleaning machine for linen and garments, operating with continuous solvent distillation, in which the drying air is heated up without the direct use of resistors. In conventional dry-cleaning machines, the rotating washwheel, which contains the garments and/or linen to be washed with an organic solvent, is connected with a solvent circuit which comprises a device for continuously distilling the same solvent, which is heated up with steam produced in a vaporization chamber through the heating by means of resistors. The washwheel also communicates with a second circuit, in which the drying air is circulated by a fan and heated up by a resistor before it enters the washwheel. Although the use of dry-cleaning machines with continuous distillation offers unquestionable advantages in terms of washing quality, it has been reduced due to high consumption and the high electric capacity installed. Documents DE-A-2 724 267, US-A-3 712 087 and EP-A-0 053 727 disclose dry-cleaning machines according to the preamble of claim 1. These documents show the use of the heated solvent for the preheating of the drying air. The present invention is aimed at providing a dry-cleaning machine with continuous solvent distillation, operating with low consumption and lower installed electric capacity compared to known washing machines. This result has been reached with the dry-cleaning machine according to the invention in which the drying air is heated up, not with a resistor or the heated solvent, but by using steam continuously produced inside the vaporization chamber located in the solvent distilling system. In this way, it is possible to reduce the electric capacity required, and less electric power is consumed during operation thanks to the use of heat produced for distillation. The invention will now be explained in greater detail in the following description of a possible embodiment intended only as an example and not a limitation, with reference to the drawing enclosed, which schematically shows the washing machine according to the invention. Referring to the above-mentioned figure, the reference numeral 1 indicates a washing tank of the washing machine according to the invention, which houses a rotating drum or basket 2 capable of containing the garments and/or linen to be washed. Tank 1 communicates with a solvent distiller 3 through a solvent circulation system, neither shown nor described, as it is of a conventional type. Tank 1 also communicates with a drying air circulation system, generally indicated as 4, which comprises an outlet pipe 5 for the air entraining the solvent removed from the garments inside drum 2, a fan 6, a cooling unit 7, which separates the solvent from the air by condensation, an air preheating unit 19 (heat pump of the cooling unit), and an inlet pipe 8 to allow the preheated air to flow into tank 1. Distiller 3 comprises a solvent vaporization chamber 10 which houses a steam heater 11 comprising a sump 11a, in which resistors 12 are installed to supply the heat required for continuously vaporizing water. According to the present invention, heater 11 communicates with a heat exchanger 15 by means of a conduit 13 through a solenoid valve 14. The heat exchanger 15 is installed in the drying air circuit downstream from preheating unit 19 on inlet pipe 8 which conveys preheated air to tank 1. A condensate return pipe 16 connects heat exchanger 15 to sump 11a of heater 11 through electrovalve 17. When the washing machine begins the drying stage, valves 14 and 17 open and the steam produced by heater 11 enters heat exchanger 15, supplying the circulating air with the heat necessary for heating it up to the operating temperature. The drying air operating temperature is controlled by a thermostat 18 located inside drying air inlet pipe 8, which causes valves 14 and 17 to close when the air has reached a set temperature, thus interrupting steam feed to exchanger 15. Thermostat 18 keeps the drying air at a constant temperature by allowing or shutting off steam feed to exchanger 15. Advantageously exchanger 15 is of the type having a finned surface. The heating system is a closed circuit, as no steam is consumed, but only heat is delivered to the users, i.e. to distiller 3 to vaporize the solvent contained in it, and to heat exchanger 15 to heat up the drying air. Steam pressure inside the system is maintained at values around 2-2.5 bar and reaches a maximum pressure of 4.5 bar when there is not heat demand from the users. The maximum pressure is controlled by a pressure sensing device 20, mounted on return pipe 16 of exchanger 15, which shuts off resistors 12 when the maximum set value is reached. The invention is not limited to the embodiment described and illustrated above, but includes any form of variation as encompassed in the appended claims.

Claims: A dry-cleaning machine for linen and garments which comprises a drum (2) containing the garments and/or linen to be washed and rotating inside a washing tank (1), means for circulating a solvent connected with said tank and including a device (3) for continuously distilling the solvent heated up with the steam produced by means of electric heating (12), means (6) for circulating drying air including air heating means comprising a heat exchanger (15) installed upstream from air inlet to said tank, characterized by using the steam produced inside said distillation device (3) as a heating medium in said heat exchanger (15). The dry-cleaning machine according to claim 1, in which said distillation device (3) comprises a heater (11) where steam is produced through a resistor (12) interceptably communicating with said heat exchanger (15). The dry-cleaning machine according to the previous claims, in which said heat exchanger has a finned surface. Machine according to the previous claims, in which the condensate coming from said heat exchanger (15) is returned to said heater (11).

Inventors: RENZACCI GABRIO, RENZACCI, GABRIO
Applicants: RENZACCI SPA, RENZACCI S.P.A. INDUSTRIA LAVATRICI
Application year: 1997
Main classification: D06F43
IPC codes: D06F43