GB2069541A - Dry cleaning machines - Google Patents

Abstract

A dry cleaning machine comprises an air circulation circuit having a condenser 44 for the solvent recovered from circulating air and an air heater 50. Between the condenser and heater, the circuit comprises a droplet recovery system D, preferably in the form of one or more perforated plates 52, 54, 56, which collects substantially all solvent droplets not previously recovered by the condenser. The components of the machine for performing the air circulation are arranged so that the path of circulating air has a substantially central plane of symmetry. In the embodiment disclosed, the plane is coincident with the central vertical plane containing the horizontal axis of rotation of the drum 14 of the machine. <IMAGE>

Description

SPECIFICATION Dry cleaning machines Known machines for dry cleaning articles such as clothes and the like, operate by an initial step of dry cleaning the body of the articles with a liquid solvent and by further drying and deodorizing steps made by means of hot air circulation. The hot air is continuously circulated, for a given time, through the body of the cleaned articles which are firstly impregnated with the liquid solvent so that, upon completion of the further steps, the articles are in a dried and deodorized state. During the air circulation steps (in which, when carried out in open circuit machines, the air is discharged externally of the room where the machine is housed) a solvent recovery step automatically takes place, and the recovered solvent is returned so the solvent tank.

The liquid solvent recovery is achieved by means of a condenser placed in the circulating air path and adapted to condense solvent fumes or vapours carried along by the air stream flowing out of the cleaning chamber. Hitherto, in order to prevent condensed liquid droplets from being carried along and brought into contact with the heater (in which case the liquid droplets would be again converted into vapour, thus rendering the solvent recovery operation ineffective), the air circuit is designed to have a tortuous and complicated configuration so that all the liquid solvent droplets are compelled to fall into the collecting space and that the air is free from droplets when reaching the heater.

The fact of providing such an air circuit of complicated configuration involves the use of components, i.e. the drying and solvent recovery plant, which are of comparatively great size and are so arranged as to occupy large space. This results in high overall dimensions of the machine, in particular when considered in its front or rear view.

According to the invention there is provided a dry cleaning machine comprising an air circulation circuit having a condenser for the solvent recovered from the circulating air and an air heater, wherein between the air condenser and the heater, a droplet recovery means is provided, said means allowing passage of circulating air therethrough but arranged to substantially prevent the air stream from bringing droplets of condensed solvent vapours into contact with said heater, said droplets being captured by said recovery means for subsequent collection, and wherein the path of circulating air is defined by a plurality of components which are arranged so that the path of circulating air has a substantially central plane of symmetry.

Preferably, the droplet recovery means comprises at least one air premeable element fitted inside a machine chamber where said condenser and heater are housed, said element or elements being disposed in the path of the circulating air.

Said at least one air permeable element comprises a metal sheet or plate, e.g. of stainless steel or brass. Alternatively, said at least one air permeable element comprises a panel of stainless steel wool or a panel of threads of plastics material formed into an entangled skein structure.

Suitably, the chamber in which said condenser, heater and droplet recovery means are housed, has a sloping. bottom wall, so that a liquid film formed on the bottom wall as a result of the droplets falling thereto from said at least one element, is allowed to run down the bottom wall toward a collector which allows the thus recovered solvent to be recirculated with the circulating air.

Conveniently, said at least one element is arranged in a raised position with respect to said bottom wall in order to create passage means for the liquid to run therethrough toward said collector.

The air permeable elements may be in parallel, spaced apart relationship with one another, the distance from each element to the adjacent one being in the range 50,to 70 mm.

The or each air permeable element suitably comprises perforations.

In one embodiment, the dry cleaning machine has a drum rotatable about a substantially horizontal axis and a central vertical plane containing said axis, said plane being coincident with said substantially central plane of symmetry.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:~ Figure 1 is a diagrammatic vertical crosssectional view of a dry cleaning machine provided with a droplet recovery system; Figure 2 is a perspective view showing, on an enlarged scale, a detail of a set of parallel, spacedapart perforated plates forming the droplet recovery system; Figure 3 is a diagrammatic rear view of the dry cleaning machine shown in Figure 1.

Figure 1 is a diagrammatic vertical crosssection through the relevant part of a machine A for dry cleaning articles such as clothes, linen and the like, in which B indicates a machine supporting frame. Only the parts of the machine relevant to the invention are shown, while other parts, such as the liquid solvent purifying and filtering parts, are omitted. A reservoir or tank 10 contains the liquid solvent, and above the tank is a chamber 12 which rotatably houses a drum 14 for containing articles to be cleaned. The rear wall 1 6 of the drum 14, i.e. the right-hand wall as viewed in Figure 1, carries at its centre a shaft 18 which is keyed to a driving pulley 20. This pulley 20 is rotated, through a belt 22, by a motor 24 and an associated pulley 26 connected to the pulley 20 by the belt 22.At its front, i.e. the left-hand side in Figure 1, the drum 14 has a door or bull's eye 28 and is open to communicate with the exterior when the door or a bull's eye 28 is opened. At its upper part, the chamber 12 communicates, through a port 30, with a manifold 32 to which is connected the intake pipe 34 of a fan C having a vertical axis and a horizontal wheel rotatable about this axis, the shaft of the fan C being driven by a motor 36. The discharge or outlet duct 38 from the fan C has a divergent, discharge cone 40 opening into a chamber D of trapezoidal section which is thoroughly sealed with respect to the exterior and has a downwardly inclined (to the left in Figure 1) bottom wall 42.At its rear side, (the right-hand side of Figure 1) the chamber D communicates with a condenser 44 to which a cooling liquid is supplied and drawn via conduits 46, 48. The chamber D, which has reduced overall dimensions, is provided at its front side with a heater 50 having heater elements, for example, armoured electric resistances, which are exposed to the air stream that has to be heated thereby, in order to cause the cleaned articles to be dried and deodorized.

In the limited space between the condenser 44 and the heater 50, said chamber D comprises a droplet-guard system F. In the example shown this system F comprises three perforated plates 52, 54, 56, which are fastened at their lower part, in parallel, spaced apart relationship with one another, to the wall 58, the distance between the spaced-apart plates being 50 to 70 mm. The plates 52, 54, 56 cause substantially all the droplets resulting from the condensation of the solvent vapour and conveyed by the air stream C, to fall into a receiving means and then to a lower collector 60 from which the liquid solvent is recirculated. The perforated plates are each made from stainless steel or other suitable metal such as brass, aluminium or other suitable alloys.

Moreover, instead of metal plates, panels made of stainless steel wool, or from plastics material formed into a thread-like, entangled skein structure, may also be used. Each plate is conveniently fastened within the chamber D for example by means of side fastening members 62, (Figure 2) and each plate extends up to the upper part of the chamber D, while a passage means, such as a lower opening of window 64, is left free between the lower edge of each plate and the upper surface 66 of the chamber bottom wall 58.

The holes formed in the plates 52. 54 are denoted by 68.

Referring now to Figure 3, it should be noted that the air circulation or ventilation system of the machine, which consists of the chamber 32, the intake duct 34, the fan C, the motor 36, the discharge or outlet conduit 38, the chamber D, and a connection 70 (which puts the interior of chamber D in communication with an intervening space 72 opening into the drum 14 and therefore into chamber 12), can be regarded, in fact, as being arranged substantially "in line". By "in line" is meant along the vertical centre line X-X of the machine shown in Figure 3 which intersects the horizontal axis of the cleaning drum 14. This is due to the fact that the provision of the droplet-guard system F has allowed tortuous and complicated air circuits to be dispensed with.Such circuits were necessary in prior machines for separating the liquid carried by the hot air stream and thus recovering the solvent. Therefore, in the embodiment disclosed with reference to the Figures, the ventilation system arranged in line along the plane X-X reduces the overall transverse dimensions of the machine, as none of the components of this system projects beyond the side walls 74, 76 (Figure 3) of the machine and consequently the ventilation system is contained within the limits of the machine width J.

In this way, the machine is rendered more compact in size, particularly as regards the front and rear views thereof.

Assuming the cleaning step has ceased, the machine will automatically perform a drying and deodorizing step of the cleaned clothes or the like, so that the above described ventilation system is made to operate. More precisely, an air stream is created which will pick up and carry away the liquid solvent with which the clothes are impregnated, until complete recovery thereof is obtained. The fan is actuated and, simultaneously, the heater 50 is switched on. As a result, the air flow is sucked in the direction of arrows 80, 82 (Figure 1) and then it is discharged through the outlet duct 38, in the direction of arrows 84, into the chamber D, where the air stream will be gradually heated as it passes through the heater 50.When the air stream meets the condenser 44, the solvent vapour carried along by the air flow will condense into droplets which are then projected against and run down the first plate 52 until reaching the bottom wall 58, from which they are brought to the collector 60. The remainder of the condensed droplets which reach the second perforated plate 54, are in turn captured by this plate and made to run down toward the bottom wall 58 until reaching the collector 60. Likewise, any last droplets which may be conveyed by the air flow C downstream of the plate 54, will be captured by the plate 56 to fall into the collector 60.In this way, when reaching the downstream region of perforated plate 56, the air stream is substantially free from solvent droplets and thus, it will flow in the direction of the arrows 86 through the heater 50 without substantially any droplets being made to strike against the heater, which would mean such droplets being again converted into the vapour state and thus causing the efficiency of the machine to be reduced. The air stream will then strike against a plurality of baffles 88 to be conveyed, through a channel 72, in the direction of arrows 90 into the drum 14 where the hot air will again pick up solvent still retained in the articles. Whereupon, the cycle comprising sucking and discharging air, condensing solvent vapour and extracting droplets of condensed vapour by means of a system F, will be repeated.

Clearly, this ventilation circuit may continue to be operated for a given time until all the solvent is recovered for use in further cleaning operations. It should be noted that the sizes of conventional machines are virtually reduced by half, as regards one of the transverse dimensions of the machine (in the direction of width I of the machine), when using the in-line arrangement of the ventilation system shown. Thus, with the same performances, it will be possible, in a machine according to the invention, to obtain a machine which is less expensive due to savings on material employed, as the above stated tortuous air circuits are eliminated, while the overall dimensions of the machine are consequently reduced.

It is to be understood that many modifications could be made to the embodiment shown without departing from the scope of the invention as defined by the appended claims.

Claims (11)

1. A dry cleaning machine, comprising an air circulation circuit having a condenser for the solvent recovered from the circulating air and an air heater, wherein, between the air condenser and the heater, a droplet recovery means is provided, said means allowing passage of circulating air therethrough but arranged to substantially prevent the air stream from bringing droplets of condensed solvent vapours into contact with said heater, said droplets being captured by said recovery means for subsequent collection, and wherein the path of circulating air is defined by a plurality of components which are arranged so that the path of circulating air has a substantially central plane of symmetry.

2. A dry cleaning machine according to Claim 1, wherein the droplet recovery means comprises at least one air permeable element fitted inside a machine chamber where said condenser and heater are housed, said element or elements being disposed in the path of the circulating air.

3. A dry cleaning machine according to Claim 2, wherein said at least one air permeable element comprises a metal sheet or plate.

4. A dry cleaning machine according to Claim 3, wherein the metal is stainless steel or brass.

5. A dry cleaning machine according to Claim 2, wherein said at least one air permeable element comprises a panel of stainless steel wool, or a panel of threads of plastics material formed into an entangled skein structure.

6. A dry cleaning machine according to any one of Claims 2 to 5, wherein the chamber in which said condenser, heater and droplet recovery means are housed, has a sloping bottom wall, so that a liquid film formed on the bottom wall as a result of the droplets falling thereto from said at least one element, is allowed to run down the bottom wall toward a collector which allows the thus recovered solvent to be recirculated with the circulating air.

7. A dry cleaning machine according to Claim 6, wherein said at least one element is arranged in a raised position with respect to said bottom wall in order to create passage means for the liquid to run therethrough toward said collector.

8. A dry cleaning machine according to any one of Claims 2 to 7, wherein said air permeable element are in parallel, spaced apart relationship with one another, the distance from each element to the adjacent one being in the range 50 to 70 mm.

9. A dry cleaning machine according to any one of Claims 2 to 8, wherein the or each air permeable element comprises perforations.

10. A dry cleaning machine according to any preceding claim, having a drum rotatable about a substantially horizontal axis and a central vertical plane containing said axis, said plane being coincident with said substantially central plane of symmetry.

11. A dry cleaning machine, substantially as hereinbefore described with reference to the accompanying drawings.