FR2683702A1 - Method for preservation of plants (vegetables) and installation for its implementation - Google Patents

Abstract

The subject of the present invention is a method for preserving plants such as, in particular, cut flowers or shrubs, and an installation for implementing this method. An installation for preserving plants comprises a plurality of containers (1) of elongate shape, each of the said containers being provided with at least one drainage orifice (3), and being provided with a surface (5) for thermal contact with a heat-exchange fluid (4). The technical field of the invention is that of the preservation of plants.

Description

Method for preserving plants and installation for placing it
in action.

DESCRIPTION
The subject of the present invention is a method for preserving plants, such as cut flowers or shrubs in particular, and an installation for implementing this method.

 The technical field of the invention is that of the conservation of plants.

 Processes are already known which allow the conservation of plants by prolonged immersion of the stem of these plants in aqueous solutions which generally contain glycerin intended to replace the sap of the plant, and at least one dye intended to give to the plant or to plants a coloring as close as possible to their natural coloring, and this after the death of these plants, so that these plants remain stable during the period of use which can in some cases be several years.

 Patent application EP 18 341 (NORDH et al) describes a process for the naturalization of plants, in particular conifers cut at their roots, which is sucked in a naturalization composition based on glycerin and water and containing dyes; according to this document, the composition is maintained at a temperature between 15 and 33 "CI naturalization being carried out in ambient air whose temperature is located in the same range, with a humidity rate lower than 60%; the composition used contains between 18 and 35% by volume of glycerin in solution in water and contains a blue dye as well as tartrazine.

 It has been discovered that, surprisingly, contrary to the teachings of EP 18 341 and against the known methods for preserving plants, it may in many cases be advantageous to maintain the plants to be treated as well as the composition used for the treatment of these plants, under very different temperature and humidity conditions.

 Because plant preservation processes have never before been the subject of truly industrial exploitation, no device is known to date making it possible to produce stabilized plants at a lower cost according to this type of process.

 Furthermore, in the case of known methods for preserving plants and more particularly in the case of the method for conserving plants according to the invention, it appears that these costs for manufacturing stabilized plants are very high due to the high labor rate. of work used to handle the plants before, during and after the conservation phase, as well as because of the importance of the energy consumption necessary for the implementation of these processes.

 The object of the present invention is to remedy the drawbacks of known plant stabilization methods and to provide a device or installation making it possible to implement these methods in a truly industrial manner and making it possible to obtain very stable stabilized plant manufacturing costs. weak.

 The solution to the problem posed consists in providing an installation for the conservation of plants such as flowers or shrubs by immersion of the stems of said plants in an aqueous composition comprising at least one dye, which installation comprises a plurality of elongated containers, each of said containers being provided with at least one drain orifice. and is provided with a contact surface and / or heat exchange with a heat transfer fluid, of substantially large size.

 Advantageously, said tanks are of rectangular section, and said contact surface is substantially planar.

 Advantageously, said tanks have a flat bottom, and a tube for transporting said fluid, of substantially rectangular section, is preferably pressed against the external face of said bottom.

 Advantageously, said tanks are thermally insulated on at least part of their outer face, and said tube is held pressed against said face of said bottom by lugs.

 Advantageously, said tanks are carried in pairs on elongated supports, and said tanks are substantially parallel to one another.

 Advantageously, the installation comprises at least one main aisle of elongated shape along an axis, and said tanks are arranged perpendicular to said axis of said main aisle, and said installation comprises at least one air supply duct and at least one air intake which extend substantially parallel to said axis of said aisle, over a large part of the length of said installation (or of a room of said installation).

 Advantageously, the installation comprises means for retaining said plants which extend parallel to said tanks, above these, which retaining means preferably comprise a guide or substantially horizontal thread-like support.

 The solution to the problem also consists in providing a method for preserving plants by immersing the stem of said plants in an aqueous solution comprising at least one dye, according to which the temperature of said aqueous solution is maintained at a value close to 35 "C. , which aqueous solution is placed in elongated tanks provided with a relatively large surface for thermal contact with a heat transfer fluid.

 Advantageously, a relative humidity of the ambient air of said installation is maintained at a value greater than 60%, preferably close to 70%.

 Advantageously, said aqueous solution contains citric acid, glycerol, and the proportion by volume of said glycerol in said aqueous solution is between 1% and 20%, preferably close to 5 to 15%.

 According to particular embodiments of the method, said solution comprises at least one colorant chosen from food colors.

The methods of conserving plants according to the invention and the installation allowing their implementation, provide numerous advantages.
Thanks to said elongated tanks which are preferably installed in a non-removable manner and which are provided with said large heat exchange surface, and preferably with said insulation means, thermal losses are thus very considerably limited and the cost is thus reduced. energetics of plant treatment; moreover, by virtue of said intimate contact surface between said heat-transfer fluid, preferably conveyed in a tube of non-circular section located outside of said tanks, a very uniform temperature of the composition contained in said tanks is obtained over the entire length. said tanks, which makes it possible to ensure a homogeneous treatment of the plants arranged all along said tanks and thus to ensure good quality of the treatment for preserving the plants, without causing unnecessary energy expenditure; moreover, by virtue of the presence of ducts for distributing treated air and distributed under the temperature and hygrometry conditions of the process according to the invention, it is possible to ensure a circulation of this homogeneous treated air throughout the room comprising the storage installation. of plants and ensure, through this, a homogeneous treatment of these plants without wasting energy.

 Furthermore, in a preferred embodiment where there is at least one channel for recovering "used" compositions, it is thus possible, at a lower cost and under optimal industrial and personnel safety conditions, to allow subsequent treatment of these aqueous solutions used by residue treatment processes; in addition, thanks to a second evacuation orifice allowing the flow of washing water in a second channel, it is possible, after the flow of the used aqueous solutions, between two treatments of different (or identical) plants in the same tank, perform a very rapid washing of said tank ensuring good cleanliness before the introduction of a new "fresh" composition allowing the treatment of other plants.

 Thanks to these provisions, the manpower times necessary for cleaning these tanks are considerably reduced and any manipulation of these tanks for this cleaning is eliminated, which results in a dead time between two conservation operations for a same bin of very short duration, which increases the profitability (or productivity) of such an installation.

 The numerous advantages provided by the invention will be better understood through the following description which refers to the appended drawings, which illustrate without any limiting character, particular embodiments of the device according to the invention and the corresponding treatment method.

 Figure 1 illustrates in cross-sectional view a preferred embodiment of tanks receiving the composition and the plants to be treated.

 FIG. 2 illustrates in cross section, a preferred embodiment of a plant conservation installation, this figure corresponding to a view along II of FIG. 3.

 Figure 3 illustrates in partial plan view, a storage installation according to the invention.

 FIG. 4 is a view along IV of FIG. 3.

 FIG. 1 illustrates a preferred embodiment of a tank of a plant conservation installation according to the invention, which tank 1 is of substantially square shape, its width 1 and the height H can for example be of around 10 cm.

 Said tray 1, of substantially square section comprises in this embodiment on each of its upper longitudinal edges, folds substantially at 90 "marked la and lb; said tray 1 is brought into intimate contact by the outer face 11 of its bottom 10, with a tube 6 in which circulates a heat transfer fluid 4 such as water for example; said tube 6 can advantageously be pressed against the bottom 10 of said tank 1 by lugs 7 in general U shape so as to ensure good heat exchange on a large surface 5; it can be seen that in this embodiment said container 1 is housed in a second container 14 constituting an envelope capable of forming a support for said container 1, which container 14 is provided on its upper longitudinal edges with folds 14a; said tanks 1 and 14 define a volume 15 delimited by the bottom of said tank 1 and the bottom of said tank 14, volume in which said tube 6 is located, which volume is preferably filled with an insulator thermal such as vermiculite for example.

 Advantageously, said tank 1 is made of stainless steel in a thin sheet, and is obtained by folding so that its cost is extremely reduced.

 It can be seen in FIG. 2 that a room 24 of a plant conservation installation according to the invention extends along a longitudinal axis XXI (perpendicular to the plane of FIG. 2) along which advantageously extends a sheath of blowing 12 of treated air which can escape from blowing vents 25 arranged for example regularly over the entire length of said sheath 12 and therefore substantially over the entire length of said room 24; a duct 13 for taking up the air which circulates substantially along the arrows F1 and F2, is also provided with a plurality of said vents 25.

 We see that said room 24 has a longitudinal aisle 9 and has two discharge channels 17; a first evacuation channel 17 (on the left in FIG. 2) can collect the used compositions, after the end of the treatment of a batch of plants in said tank 1, which used composition can flow through a drain orifice 31 preferably situated at one end of said tank 1, which orifice is extended by a drain pipe opening into said gutter 17.

 We see that on the right in the figure is provided in this embodiment a second channel 17 in which the rinsing water from said tank 1 can flow, which rinsing is necessary after the evacuation of a used composition and beforehand the introduction of a new or fresh composition for the treatment of a new batch of plants in said tank 1.

 It can be seen that advantageously said tank 1 comprises a second drain orifice 32 located at a second end of said tank which orifice is extended by a flow pipe which opens into said gutter 17 (on the right in the figure).

 It can be seen that according to the invention, said tank 1 comprises in its lower part said tube 6 for transporting said heat transfer fluid, which tube 6 can in the preferential case where two of said tanks are juxtaposed and parallel to each other, flow successively under a first of said tanks 1 then under a second of said tanks 1, so as to form a pin as illustrated in FIG. 3, said tube 6 being connected (on the left in FIG. 2), at one end to a collector 19 for example a departure collector of said heat transfer fluid, and at its second end to a second manifold 20 for example an inlet manifold of said heat transfer fluid.

 It is seen that advantageously, said collectors 19, 20 can extend longitudinally in said room, along a wall 23 of said room which is advantageously thermally well insulated from the outside of said room.

 It can be seen that in this embodiment, said container 1 is surrounded by said second container 14 by means of which said container 1 can be supported by vertical supports 21, which vertical supports can also support means 22 for retaining plants in a substantially position. vertical, to allow the introduction of a large number of plants aligned substantially vertically in said tank.

 In an exemplary embodiment of tanks according to the invention, said tanks 1 and 14 have a length B for example of the order of 5 meters.

 With reference to FIG. 3, it can be seen that said room 24 comprising the plant for the conservation of plants according to the invention is delimited by walls or walls 23 which are advantageously thermally insulated and extending parallel to its longitudinal axis XX1, said blowing 12 and return 13 ducts for the treated air making it possible to maintain the temperature and the humidity in the room under the conditions provided for in the method according to the invention, each of said ducts being provided with a plurality of vents 25 ; said room also includes said collectors 19 for the start and 20 of a heat transfer fluid which can circulate in said tubes 6 attached to said tanks 1, which tanks I are arranged parallel to each other and perpendicular to said axis XX1, in pairs, said tubes 6 thus constituting pins connected to said collectors 19 and 20; we see that between each pair of said tanks 1 is provided a secondary aisle 26 allowing the passage of personnel handling the plants and allowing accessibility to the organs of the installation.

 With reference to FIG. 4, it can be seen that in a particular embodiment concerning the treatment of plants of relatively reduced height, for example of the order of 1 m, each group of said trays 1 can comprise two pairs of said trays 1, each of the trays of one of said pairs being parallel to each other and substantially at the same height, said two pairs of trays being supported by a common support comprising a substantially vertical upright 21a, substantially vertical uprights 21a, 21b, 21c and horizontal uprights 281, which horizontal mounts 281 can advantageously carry said means 22 for retaining said plants 27, which retaining means can for example comprise a metal wire.

 We see in this embodiment that said tanks 1 are supported by horizontal supports 282, which tanks 1 are provided in their lower part with said tube 6 for transporting said heat transfer fluid; it can also be seen that said secondary aisle 26 is provided between two of said groups of two pairs of superimposed bins, so as to leave a free passage of width A sufficient for the passage of personnel.

Claims (11)

 1. Installation for the conservation of plants characterized in that it comprises a plurality of tanks (1) of elongated shape, each of said tanks being provided with at least one orifice (3) for emptying, and being provided with a surface (5) thermal contact with a coolant (4).  2. Installation according to claim 1 characterized in that said tanks are of rectangular section.  3. Installation according to any one of claims 1 and 2 characterized in that said contact surface is substantially planar.  4. Installation according to any one of claims 1 to 3 characterized in that said tanks have a flat bottom (10), and in that a tube (6) for transporting said fluid (4) of substantially rectangular section, is pressed against the external face (11) of said bottom.  5. Installation according to any one of claims 1 to 4 characterized in that said tanks are thermally insulated on at least part of their outer face.  6. Installation according to any one of claims 1 to 5 characterized in that said tube (6) is held pressed against said face of said bottom by lugs (7).  7. Installation according to any one of claims 1 to 6 characterized in that said tanks are carried in pairs on supports (8), and said tanks are substantially parallel to each other.  8. Installation according to any one of claims 1 to 7 characterized in that it comprises at least one aisle (9) main, of elongated shape along an axis (xxî) comprising said tanks arranged perpendicular to said axis of said main aisle and said installation comprises at least one air blowing sheath (12) and at least one air return sheath (13) which extend substantially parallel to said axis of said aisle, over a large part of the length of said installation .  9. Installation according to any one of claims 1 to 8 characterized in that it comprises means for retaining said plants which extend parallel to said tanks, above these, which retaining means preferably carry a guide or threadlike support (22) substantially horizontal.  10. A method for preserving plants by immersing the stem of said plants in an aqueous solution comprising at least one dye, characterized in that the temperature of said aqueous solution is maintained at a value close to 35 "C, which aqueous solution is arranged in elongated tanks provided with a relatively large surface for thermal contact with a heat transfer fluid, and in that a relative humidity of the air of said installation is maintained at a value greater than 60%.  11. Method according to claim 10 characterized in that said aqueous solution contains citric acid and glycerol, and in that the proportion by volume of said glycerol in said aqueous solution is between 1% and 18%.