PROCESS AND APPARATUS FOR EVAPORATING A SOLUTION

Abstract: Process for evaporating a solution, wherein a certain volume of the solution is introduced into a reser­ voir, a portion of the solution contained in the reservoir is transferred to a first compartment outside the reservoir, and the portion of solution contained in the first compart­ ment is gradually and continuously transferred to an impreg­ nation member consisting of a material capable of absorb­ ing a liquid the said member being placed on a support outside the reservoir and outside the first compartment. To make the process easier to use and to avoid losses of solution, e.g. during the transport of the evaporating apparatus, the said process is characterized in that a passage enabling communication to be established for the transfer of a portion of the solution from the reservoir to the first compartment is opened inter­ mittently; an external pressure is exerted on at least one elastic wall of the reservoir when the said passage is open, in order to accomplish the transfer of a portion of the solution from the reservoir to the first compart­ ment; the said passage is closed; and the said passage is kept closed during the time intervals between inter­ mittent transfers of the portions of the solution.

Description: The invention relates to a process for evaporating an evaporable solution, said process comprising: introducing a certain volume of the solution into a reservoir, transferring a portion of the solution contained in the reservoir to a first compartment outside the reservoir, and gradually and continuously transferring the portion of solution contained in the first compartment to an impregnation member consisting of a material capable of absorbing a liquid, the said member being placed on a support outside the reservoir and outside the first compartment. The invention relates, in addition, to an appara­ tus for evaporating an evaporable solution, the said appa­ ratus containing: a vessel comprising a reservoir designed to con­ tain a certain volume of the solution, a first compartment outside the reservoir, a passage for the transfer of solution from the reservoir to the first compartment, means for accomplishing the transfer of a portion of solution from the reservoir to the first com­ partment through the said passage, an impregnation member placed on a support outside the reservoir and outside the first com­ partment, and means for gradually and continuously transferring the solution contained in the first compartment to the impregnation member. In the context of the invention, the solution can be an evaporable solution of any kind, e.g. a perfume, an insecticide, a bactericide, a mould inhibitor, and the like. Evaporating vessels which permit the evaporation of a solution of perfume, from the exposed end of a wick whose other end is directly immersed in the solution, are already known. Evaporating vessels in which a disc of water-­ absorbent material is placed in contact with the exposed end of the wick, and is thereby impregnated with the solution of perfume in order to evaporate the latter into the air, are also known. In all the known vessels of the types which have just been mentioned, the wick is directly immersed in the solution of perfume contained in the vessel, so that the most volatile component of the perfume is the first to evaporate; the odour of this perfume then becomes very weak after a week or two, and cannot be preserved for a longer period. This drawback is remedied by means of a process and an apparatus which are known, of the type described at the beginning of this description. A process and apparatus of this kind are described in US Patent No. 4,477,414. This known process and apparatus have the following drawbacks: its use requires a number of mani­ pulations, both when first used and every time it is desired to transfer a portion of the solution from the reservoir to the first compartment, or if it is desired to seal the reservoir hermetically, e.g. for transporting the apparatus. The aim of the invention is to solve the problem of providing a remedy for these drawbacks and, in addition, of proposing an apparatus of the kind defined at the beginning of this description but having a simpler structure in order to reduce substantially the costs of manufacturing an apparatus of this kind. According to the invention, this problem is sol­ ved by means of a process of the kind defined at the beginning of this description, which is characterized in that it comprises: intermittently opening a passage enabling communication to be established for the transfer of a portion of the solution from the reservoir to the first compartment, exerting an external pressure on at least one elastic wall of the reservoir when the passage is open, in order to accomplish the transfer of a portion of the solution from the reservoir to the first compartment, closing the passage, and keeping it closed during the time intervals between intermittent transfers of portions of the solution. A preferred embodiment of the process according to the invention is characterized in that it comprises: intermittently opening the following: (i) an opening of the first compartment, which brings the inside of this compartment into direct communication with the atmosphere, and (ii) a passage enabling communication to be established for the transfer of a portion of the solution from the reservoir to the first compartment, exterting an external pressure on at least one elastic wall of the reservoir when the opening and the passage are open. in order to accomplish the transfer of a portion of the solution from the reservoir to the first compartment, closing said opening of the first compartment and the passage, and keeping the opening and the passage closed during the time intervals between intermittent transfers of portions of the solution. According to the invention, the problem stated above is solved, furthermore, by means of an apparatus of the kind mentioned at the beginning of this description, which is characterized in that the reservoir has at least one elastic wall, the first compartment has an opening which brings the inside of this compartment into direct commu­ nication with the atmosphere, and in that the apparatus comprises in addition: means for opening and closing, respectively, the passage for the transfer of the solution, and thereby for permitting and preventing, respec­ tively, the said transfer of a portion of the solution from the reservoir to the first compart­ ment. A preferred embodiment of the apparatus according to the invention is characterized in that it comprises, in addition, means for opening and closing, respectively, the said opening of the first compartment. The advantages obtained by means of this invention consist essentially in that it makes it possible to achieve simultaneously the following objectives: - the evaporation of the solution takes place while a constant proportion of its components is preserved, this being the case virtually throughout the period of use of the evaporating apparatus, - the number of manipulations required for using the apparatus are considerably reduced, - it is now possible to achieve hermetic sealing of the reservoir for transporting the apparatus without the need to disassemble the apparatus, - the simplified and compact structure of the apparatus enables its price to be reduced. In that which follows, the invention is described in greater detail by means of drawings, which illustrate only a preferred embodiment. Fig. 1 illustrates a partially sectional view of an apparatus according to the invention. Fig. 2 illustrates an enlarged sectional view of the central portion of the apparatus according to Fig. 1. In this view, the passage (17, 28) is closed by the plug 41 which is a part of the lid 11 in Fig. 1. Fig. 3 illustrates an enlarged sectional view similar to that shown in Fig. 2, but showing the plug 41 in a position in which it does not close the passage (17, 28) in Fig. 2. Fig. 4 illustrates a top view of the apparatus according to Fig. 1. The evaporating apparatus shown in Fig. 1 comprises a vessel 12 and a lid 11. The vessel 12 is cylindrical in shape and has side walls 13 and a bottom 14. The vessel 12 is manufactured in a flexible and elastic plastic, e.g. by moulding (injection blow mould- ing) of semi-transparent polyethylene. The vessel 12 comprises a support plate 21 which divides the inside of the vessel into a lower portion and an upper portion. The lower portion of the vessel enclosed between the support plate 21 and the base 14 of the vessel forms a reservoir 16 designed to receive a certain volume of the solution 18 to be evaporated. A connection 71 between the plate 21 and the wall 13 prevents flow of liquid between the peripheral outer wall of plate 21 and the wall 13. The support plate 21 contains a neck 22 which extends upwards from its central portion. This neck 22 is the neck of the reservoir 16. The neck 22 is normally closed by a plug 23, which is driven into place. It is hence necessary to remove this plug when it is desired to introduce the solution to be evaporated into the reservoir 16. As shown schematically in Fig. 1 and in greater detail in Figs. 2 and 3, the space enclosed between the outer side wall 13 of the vessel 12 and the neck 22 in the upper portion of the vessel is divided into two compartments. A first compartment 26 is bounded by a cylindrical outer wall 25, the outer wall of the neck 22, an inner cylindrical wall 36 and a base wall 35. The remainder of the upper portion of the vessel forms a second compartment 51. An annular impregnation member 31 is mounted in the outer compartment 51 on the support plate 21. The impregnation member 31 consists of a material capable of absorbing a liquid, e.g. water, such as filter paper made of natural fibres or synthetic fibres. A layer 33 is made of a fibrous material capable of absorbing a liquid, e.g. water. The layer 33 is, e.g., a capillary wick which is placed between the base wall 35 of the compartment 26 and the support plate 21. The layer 33 is in contact with the impregnation member 31. The base wall 35 of the compartment 26 has an orifice 32 which brings the inside of the compartment 26 into communi­ cation with the layer 33 of fibrous material. The compartment 26 has an opening 29 which brings the inside of the compartment 26 into direct communication with the atmosphere when it is open. In the position of the lid 11 illustrated in Fig. 2, the opening 29 is closed by the portion 48 of the lid 11. In the position of the lid shown in Fig. 3, the lid has been moved slightly upwards and the opening 29 is open. The support plate 21 has a bore 27 which passes through this plate in a portion of the latter enclosed between the neck 22 and the cylindrical wall 36 of the compartment 26. A feed tube 17 placed in the reservoir 16 is provided for transferring a portion of the solution 18 from the reservoir 16 to the compartment 26. The tube 17 extends between a point close to the bottom 14 of the vessel 12 and the bore 27. The upper end of the tube 17 is inserted into the bore 27. The lower end of the tube 17 is preferably arranged in a cavity 15 formed in the bottom 14 of the vessel 12. In its upper end, the feed tube 17 has an orifice 28 which is at the same level as the upper end of the bore 27. The orifice 32 in the base wall 35 of the compartment 26 is at a level below the level of the upper end of the bore 27 and of the orifice 28 of the feed tube 17. During the transfer of a portion of the solution 18 from the reservoir 16 to the compartment 26, the orifice 28 functions as an overflow orifice, i.e., if the volume transferred is excessive with respect to the level of the orifice 28, the portion of the liquid volume in excess above this level returns to the reservoir 16 through the orifice 28. The volume of solution 34 contained in the compartment 26 flows through the orifice 32 to the layer of fibrous materials 33 and thence to the impregnation member 31. Since the layer 33 transports the solution by capillarity, the transfer of the solution from the compartment 26 to the impregnation member 31 takes place gradually and continuously. The support plate 21, as well as the walls of the compartment 26, are manufactured in a flexible and elastic plastic, e.g. by moulding (injection blow moulding) of semi-transparent polyethylene. A removable annular disc 49 is inserted between the vessel 12 and the lid 11. The disc 49 bounds the upper portion of the outer compartment 51, and has windows 53. This disc is preferably transparent and rigid, and is made, e.g., by moulding (injection moulding) of polymethyl methacrylate. The disc 49 is pinned onto the upper edge of the vessel 12 and is hence firmly attached to the latter. The lid 11 contains a plug 41 and an annular disc 48, which has a cylindrical flange 54. The plug 41 is preferably manufactured in a flexible plastic, e.g. by moulding (injection blow moulding) of polyethylene. The annular disc 48 is preferably transparent and is manu­ factured in a rigid plastic, e.g. by moulding (injection moulding) of polymethyl methacrylate. The plug 41 has an internal thread 42 enabling this plug to be screwed on the neck 22, which has an external thread 24 which corresponds to the internal thread of the plug 41. The arrangement of various constituent parts of the evaporating apparatus is such that, when the plug 41 is screwed on the neck 22, an hydraulic gasket 60 which comprises a gasket ring 61 and a sponge ring 62 is compressed between the lower end of the plug 41 and the top surface of the wall 36, whereby the lower end of the plug 41 and the top surface of the wall 36 form a mechanical gasket 59 when they come into contact. In this way the upper orifice 28 of the feed tube 17 is closed as shown in Figs. 1 and 2. In a more simple embodiment the hydraulic gasket 60 can be absent. In this case the orifice 22 can be closed simply by the lower end of the plug 41 when this plug is screwed downwards. In a preferred embodiment, in the position of the plug 41 shown in Figs. 1 and 2, the annular disc 48 of the lid 11 closes the opening 29 of the compartment 26. Fig. 2 shows the closing of the orifice 28 by the plug 41, and the closing of the opening 29 of the compartment 26 by the annular disc 48 of the lid 11. In a preferred embodiment, these two closing operations take place simultaneously. The annular disc 48 of the lid 11 has several windows 52 which are, e.g., of the shape shown in Fig. 4. By rotating the annular disc 48 relative to the vessel, it is possible to position the windows 52 so that they are partially or completely superposed over the windows 53 of the annular disc 49, which is inserted between the vessel 12 and the lid 11. When these windows coincide completely, the open area of the lid is approximately 50% of the total area covered by the lid 11. If the windows 52 and the windows 53 do not coincide, even partially, the annular discs 48 and 49 form a virtually sealed assembly which has no opening towards the top. The upper portion of the side wall 13 of the vessel 12 also has windows 56 arranged along the cylindrical periphery of the said wall. The cylindrical flange 54 of the lid 11 also has windows 55. By rotating the annular disc 48 of the lid 11, it is possible to bring the windows 55 of the cylindrical flange of the lid 11 into partial or complete coincidence with the windows 56 of the wall 13 of the vessel. In this way, it is possible to adjust the lateral aeration of the compartment 51 in which the impregnation member 31 is situated. If the windows 55 and 56 do not coincide, the side wall 13 of the vessel is completely closed. By virtue of the windows 52, 53, 55, 56 which have just been described, it is hence possible to adjust the aeration of the compartment 51 over a wide range of variation, bet­ ween total closure of this compartment towards the outside, and maximal opening of the said compartment towards the outside when the windows 56 of the vessel coincide fully with the windows 55 of the lid and the windows 52 of the lid 11 coincide fully with the windows 53 of the annular disc 49. The embodiment shown in Figs. 1-4 includes means 63, shown in Figs. 1 and 4, for preventing rotation of the disc 49 with respect to the wall 13 of the vessel 12 when the disc 48 is rotated. The means 63 comprise pins 64 on the wall 13 and slots 65 in the disc 49. As shown in Figs. 1 and 4 the pins 64 are inserted in the slots 65. The plug 41 has a cylindrical edge which rests on an annular surface of the disc 48 so that, when the plug 41 is screwed on the neck 22, the plug pushes the disc 48, and thereby the lid 11, downwards. The plug 41 and the disc 48 of the lid 11 can be manufactured integrally or they can be independent parts, the plug 41 in this case being inserted in a circular opening in the centre of the disc 48. The latter embodi­ ment has the advantage that the disc 48 can be rotated independently of the plug 41. It is thus possible to modify the degree of aeration of the compartment 51 without the need to modify either the position of the plug 41 with respect to the neck 22, or the position of the disc 48 of the lid 11 with respect to the opening 29 of the compartment 26. The evaporating apparatus can, in addition, include a ratchet mechanism (not shown in the figures) for drawing attention to the closing and/or opening of the orifice 28, and preferably also the closing and/or opening of the opening 29. The pitch of the internal thread 42 of the plug 41 and the external thread 24 of the neck 22 is such that a rotation through an angle of between 30o and 180o in a given direction is sufficient to open the orifice 28 and, if desired, simultaneously also the opening 29, and that a rotation through the same angle in the opposite direction is sufficient to seal simultaneously and hermetically the said orifice and, if desired, simultaneously also the said opening. The operation of the evaporating apparatus described above is as follows: The plug 23 is removed from the neck 22, a certain volume of the evaporable solution 18 is introduced into the reservoir 16 through the neck and the latter is closed with the plug 23. To transfer a portion of the solution 18 from the reservoir 16 to the compartment 16, the procedure is as follows: The plug 41 is unscrewed by rotating it through an angle of between 30o and 180o in order to open the orifice 28 of the feed tube 17. Preferably, this also enables the opening 29 of the compartment 26 to be opened. An external pressure is then exerted on the walls of the reservoir 16, preferably a vertical or lateral pressure on the side walls 13 of the vessel 12, in order to cause a portion of the solution 18 to rise through the feed tube 17 and the orifice 28 and thereby to transfer such a portion 34 to the compartment 26 (in Fig. 3 the flow of liquid through the feed tube 17, through the sponge 62 and into the compartment 26 is illustrated with arrows). When this transfer has been accomplished, the orifice 28 is closed with the plug 41, and the opening 29 is preferably also closed with the disc 48, by rotating the plug 41 in the appropriate direction. During the time intervals between the intermittent transfers of portions of the solution, the orifice 28 and preferably also the opening 29 are kept closed. In this way, the solution contained in the reservoir 16 or in the compartment 26 is prevented from accidently flowing out of the evaporating apparatus, e.g. during transport of the latter. As illustrated with arrows in Fig. 3 the portion of solution 34 contained in the compartment 26 gradually and continuously flows through the orifice 32 and the layer of fibrous material 33 to the impregnation member 31. The solution impregnated on this component evaporates through the windows 52, 53, 55, 56 described above. This is illustrated by dash line arrows in Fig. 3. The user hence has the possibility of transferring portions of solutions from the reservoir 16 to the compartment 26 intermittently whenever he judges this to be necessary, or when he observes that the solution contained in the compartment 26 is depleted. To facilitate this observation, the disc 48 of the lid 11 and the disc 49 are preferably transparent. In the context of the invention, the solution to be evaporated may be, e.g., a perfume. The latter may be used: - in the pure state, or - diluted with one or more solvents, or - diluted with a mixture of water with one or more solvents, or - diluted with a mixture of water with one or more solvents and with a surfactant. The perfume or the solution containing the perfume may, in addition, contain other commonly used additives such as, e.g., a fungicide, a colouring, an agent for preventing the ignition of the solution (an agent of this kind is commonly known as a fire retardant), and the like.

Claims: 1. Process for evaporating a solution, said process comprising: a) introducing a certain volume of the solution (18) into a reservoir (16), b) transferring a portion of the solution (18) contained in the reservoir (16) to a first compartment (26) outside the reservoir (16), and c) gradually and continuously transferring the portion of solution (34) contained in the first compartment (26) to an impregnation member (31) consisting of a material capable of absorbing a liquid, the said member being placed on a support (21) outside the reservoir (16) and outside the first compartment (26), the said process being characterized in that it further comprises: d) intermittently opening a passage (17,28) enabling communi­ cation to be established for the transfer of a portion of the solution from the reservoir (16) to the first compart­ ment (26), e) exerting an external pressure on at least one elastic wall (13) of the reservoir (16) when the passage (17,28) is open, in order to accomplish the transfer of a portion of the slution (18) from the reservoir (16) to the first compartment (26), f) closing the passage (17,28), and keeping it closed during the time intervals between intermittent transfers of portions of the solution. 2. Process for evaporating a solution, said process comprising: a) introducing a certain volume of the solution (18) into a reservoir (16), b) transferring a portion of the solution (18) contained in the reservoir (16) to a first compartment (26) outside the reservoir (16), and c) gradually and continuously transferring the portion of solution (34) contained in the first compartment (26) to an impregnation member (31) consisting of a material capable of absorbing a liquid, the said member being placed on a support (21) outside the reservoir (16) and outside the first compartment (26), the said process being characterized in that it further comprises: d) intermittently opening the following: (i) an opening (29) of the first compartment (26) which brings the inside of this compartment into direct communication with the atmosphere, and (ii) a passage (17,28) enabling communication to be established for the transfer of a portion of the solution from the reservoir (16) to the first compartment (26), e) exerting an external pressure on at least one elastic wall (13) of the reservoir (16) when the opening (29) and the Passage (17,28) are open, in order to accomplish the transfer of a portion of the solution (18) from the reser­ voir (16) to the first compartment (126), f) closing said opening (29) of the first compartment (26) and said passage (17,28), and keeping the opening and the passage closed during the time intervals between inter­ mittent transfers of portions of the solution. 3. Process according to Claim 2, characterized in that the opening and closing, respectively, of the opening (29) and of the passage (17, 28) take place simultaneously. 4. Apparatus for evaporating a solution, the said apparatus containing: a) a vessel (12) comprising a reservoir (16) designed to contain a certain volume of the solution (18), b) a first compartment (26) outside the reservoir (16), c) a passage (17,28) for the transfer of solution from the reservoir (16) to the first compartment (26), d) means for accomplishing the transfer of a portion of solution from the reservoir (16) to the first compartment (26) through the passage (17,28), e) an impregnation member (31) placed on a support (21) outside the reservoir (16) and outside the first compartment (26) and f) means (32, 33) for gradually and continuously transferring the solution (34) contained in the first compartment (26) to the impregnation member (31), the said apparatus being characterized in that: g) the reservoir has at least one elastic wall, h) the first compartment (26) has an opening (29) which brings the inside of this compartment into direct communication with the atmosphere, and in that the apparatus comprises in addition: j) means for opening and closing, respectively, the passage (17, 28) for the transfer of the solution, and thereby for permitting and prevent­ ing, respectively, the said transfer of a portion of the solution from the reservoir (16) to the first compartment (26). 5. Apparatus according to Claim 4, characterized in that it comprises, in addition, means for opening and closing, respectively, the said opening (29) of the first compartment. 6. Apparatus according to Claim 4, characterized in that the impregnation member is placed in a second compartment (51) outside the reservoir (16) and outside the first compartment (26), and in that the reservoir, the first compartment and the second compartment form a compact structure contained in the vessel (12). 7. Apparatus according to Claim 4, characterized in in that it comprises a removable lid (11) containing means for closing the passage (17, 28) provided for the transfer of solution from the reservoir (16) to the first compartment (26). 8. Apparatus according to Claim 5, characterized in that it comprises a removable lid (11) containing means for closing the passage (17, 28) provided for the transfer of solution from the reservoir (16) to the first compart­ ment (26), and for closing the opening (29) provided for bringing the inside of the first compartment (26) into direct communication with the atmosphere. 9. Apparatus according to Claim 6, characterized in that the vessel (12) comprises a support plate (21) which divides the inside of the vessel into a lower portion and an upper portion; the reservoir (16) occupies the lower portion of the vessel (12); the support plate (21) contains a neck (22) which is the neck of the reservoir (16) and which extends up­ wards from the central portion of the said plate; and the space enclosed between the outer side wall (13) of the vessel (12) and the outer wall of the neck (22) in the upper portion of the vessel is divided into two compartments, the inner compartment being the said first compartment (26) and the outer compartment being the said second compartment (51). 10. Apparatus according to Claim 9, characterized in that the passage for the transfer of solution from the reservoir (16) to the first compartment (26) comprises a feed tube (17) which extends between a point close to the bottom (14) of the reservoir (16) and a bore (27) in the support plate (21), said bore being close to the neck (22) and the upper end of the tube (17) being inserted into the bore (27). 11. Apparatus according to Claim 10, characterized in that the first compartment (26) has a base wall (35) placed on a layer (33) of a fibrous material capable of absorbing a liquid, said layer being placed between the base wall and the support plate (21) and the layer being in contact with the impregnation member (31); the base wall (35) has an orifice (32) en­ abling the solution contained in the first compartment (26) to flow to the layer (33) and thence to flow to the impregnation member (31), the orifice being at a level below the upper orifice of the tube (17) when the bottom (14) of the vessel is in the horizontal posi­ tion. 12. Apparatus according to Claim 10, characterized in that it comprises a removable lid (11) which contains a plug (41) which has an internal thread (42) enabling this plug to be screwed on the neck (22), which has an external thread (24) which corresponds to the internal thread of the plug; the arrangement of the different constituent parts being such that, when the plug (41) is screwed on the neck (22), the lid (11) comes into contact with an outer wall (25) of the first compartment (26) and thereby closes the opening (29) of the first compartment (26) at the same time as the lower end of the plug (41) comes into contact with a surface of the support plate (21) and thereby closes the upper orifice (28) of the feed tube (17). 13. Apparatus according to Claim 12, characterized in that the pitch of the internal thread (42) and of the external thread (24) is such that a rotation through an angle of between 30° and 180° in a given direction is sufficient to open simultaneously the said passage (17, 28) and the opening (29), and that a rotation through the same angle in the opposite direction is sufficient to seal simultaneously and hermetically the passage and the opening. 14. Apparatus according to Claim 4, characterized in that it comprises a ratchet for drawing attention to the closing and/or opening of the said passage (17, 28).

Inventors: LOSI, SALVATORE ANTONIO
Applicants: L. GIVAUDAN & CIE SOCIETE ANONYME
Application year: 1988
Main classification: A61L9
IPC codes: A61L9, B01D1