WO1986006928A1 - Method for the treatment of the atmosphere prevailing in greenhouses and other sheltered housings, and installation for implementing such method - Google Patents

Abstract

Method and installation for treating the atmosphere prevailing in greenhouses and other sheltered housings, comprising the taking of air (1) which is intended to create the atmosphere in the shelter or the greenhouse, selectively, inside or outside said local, subjecting said air to at least one filtration operation (3), at least one controlled humidification operation (5) comprising at least one extraction stage (6) of the liquid phase present in said air, at least one operation for regulating the temperature of said air and finally introducing in the shelter or the greenhouse the air thus treated (B) added or not with appropriate agents for a specific treatment of vegetables (9) according to a regular circulation mode which is opposed to any so-called phenomenon of air draft, while maintaining the internal atmosphere under controlled pressure and, if desired, the recovery of calories in excess within said atmosphere with the view to re-heating the soil or the subsoil.

Description

 Process for treating the atmosphere prevailing in greenhouses and other sheltered enclosures, and installation for implementing this process.

The present invention relates to a process for treating the atmosphere prevailing in greenhouses and other sheltered enclosures. It also covers the means and installations for the implementation of this process. It is well known that when one cultivates under cover and in particular in greenhouses, it is imperative, to have a good vegetation, to act more especially on the hygrometry and the temperature of the air circulating in these premises. The solutions currently known for acting on these parameters are of two types, namely: the solution using the so-called "cooling" principle and the second, that using the so-called "fog System" principle.

The so-called "cooling" process consists of putting the shelters or greenhouses under vacuum by fans located opposite damp walls. The outside air therefore penetrates inside the premises; it is moistened and refreshed. The disadvantage of this system lies in the fact that the internal humidity is not uniformly distributed throughout the volume of the room as well as the temperature.

These phenomena are directly reflected on the vegetation, the development and growth of which differ from one zone to another depending on the humidity and temperature. This is how the vegetation is much more lush in the vicinity of the damp and cool walls. On the other hand, the erratic passage of air as well as the creation of air currents in certain areas is particularly detrimental.

The second process called "fog system" consists in diffusing a mist inside the shelters or greenhouses. The disadvantage of this system lies in the fact that it does not allow the ambient air to be renewed. The cultures are therefore permanently in the presence of a little air renewed. Such a process, although it may be satisfactory, requires special precautions. In particular, it is imperative to avoid drafts which would cause, in certain areas, a sort of immediate condensation of the mist and intensive humidification of certain areas of the crop to the detriment of other non-humidified areas. Another drawback lies in the fact that microjets are used for this diffusion, microjets whose nozzles are subject to frequent closures due to the presence of various micro-particles in the water admitted. Although we can act on the humidity, it is much more difficult on the other hand to act on the temperature and vice versa.

The two processes recalled above have the disadvantage of being relatively expensive and of not making it possible to make the most of the action of phytosanitary agents, due to the fact that, in the first process, these agents are distributed irregularly and that, in the second, these agents risk blocking the nozzles in the manner mentioned above. The present invention overcomes these various drawbacks and aims at a simple and economical method as well as an installation for its implementation.

The process of the invention allows regular and better quality vegetation and crops by better air conditioning, while allowing specific treatments thanks to the creation of atmospheres uniformly distributed over the whole extent of a crop and having the same characteristics. temperature, hygrometry, as well as contents of special agents possibly present in these atmospheres.

The process of the invention is essentially characterized in that it consists in taking the air which will be intended to create the atmosphere in the shelter or the greenhouse at any point outside or inside said room, to subject this air to at least one filtration operation, at least one controlled humidification operation comprising at least one stage of extraction of the liquid phase present in said air, at least one operation for adjusting the temperature of this air, to admit into the shelter or greenhouse the air thus treated, with or without agents suitable for a specific treatment of plants, according to a regular circulation mode such that it opposes any so-called air flow phenomenon, by maintaining the internal atmosphere under controlled pressure and, if desired, recovering the excess calories in this atmosphere with a view to its recycling and / or reheating the soil or the subsoil. The installation for implementing the above process is essentially characterized in that it comprises:

an air sampling and / or selection station to be admitted into the shelter or into the greenhouse, this selection being made on the air inside and / or outside said shelter;

a station for adjusting the flow rate, speed and pressure of admission of said air thus sampled and selected;

- a filtration station;

- At least one air conditioning station in which the air is subjected to a washing action in order to give it the desired humidity level and to bring it to the desired temperature;

- at least one air purification station thus washed to rid it of the excess liquid phase which may be there, possibly followed by at least one air treatment station by any agent suitable for an intervention specific to the culture in question;

- at least one water withdrawal station with any means of treatment before admission to the installation; at least one general control station for adjusting the temperature, the humidity level, the pressure, the flow rate, the speed, the content of specific treatment agent; - means for regular and uniform air distribution within the shelter or greenhouse, opposing the so-called air flow or turbulence phenomena, and finally, means for maintaining the atmosphere of the room under a uniform and constant pressure at a predetermined value in connection with the air intake and distribution circuit and, optionally means for recovering excess calories and recycling or injecting them into the ground or basement of said facility;

- And, if desired, means for controlling the water content of said soil or subsoil.

Advantageously, the specific treatment agents are chemical agents (known for this use) which are in liquid, solid or gaseous form. Other advantages and characteristics of the invention will emerge more clearly from the description which follows, given with reference to the appended drawings in which:

- Figure 1 is a schematic view illustrating the method of the invention;

- Figure 2 is a schematic view of a possible means for the selection of the air admitted into the installation;

- Figure 3 is a schematic view of an exemplary possible embodiment of an air conditioning chamber;

- Figure 4 is an example of a compartment for regulating parameters for the proper functioning of the installation (temperature, humidity, flow rate, speed, pressure, content of specific treatment agents); - Figure 5 is an explanatory diagram of a possible circuit for the water supply of the air conditioning and treatment chamber (s); - Figures 6 and 6A are views respectively in plan and in elevation of a possible embodiment of the air distribution means inside a greenhouse.

Referring to these drawings, there is shown in Figure 1, schematically, the part of the installation according to the invention, intended to bring into a greenhouse, not shown, air conditioning and / or treated. This installation comprises a ventilation group (4) working in suction-discharge for, on the one hand, sucking in the air (A) coming from outside and / or inside said greenhouse and, on the other hand , discharge into the air conditioning chamber (5) which will be described below said air for its further treatment. The selection of the admitted air (A) is advantageously made by means of a selector (1) placed at the entrance to the installation. An example of such a selector will be described below with reference to FIG. 2. With a view to adjusting the speed and / or the air flow, the installation comprises (at 2) a device called a valve. opening type. This assembly is immediately followed by a group of filters (3) of any known type intended for a first purification of the air to rid it of any foreign substance in suspension in the aspirated volume. Such filters may or may not be combined with anti-bacterial devices. The ventilation group (4) is self-regulating or not by a control center (17) in relation to internal or external sensors in the greenhouse or in the shelter, so as to be able to act on the speed, the pressure, the flow , humidification and temperature as will be seen below. The ventilation group can be controlled by an electronic brake system, to avoid mechanical wear or by any other braking mode such as electric brake. Such systems are well known in the art and need not be described in more detail here.

On the discharge side of this ventilation group (4), a so-called air conditioning chamber (5) is provided, the purpose of which is to wash the air which is admitted thereto, this washing being done by means well known in the art. One of the possible examples of such a washing is illustrated diagrammatically in FIG. 3 which will be described in more detail later. On leaving the air conditioning chamber (5), the air stream (A) is freed of any excess liquid phase by a system which is also well known (6), known as a drop separator system or "drop trap". The installation can be completed by "an additional air conditioning chamber (7) itself followed by its" drip trap "(8).

According to the invention, the installation may include a chamber (9) called an air treatment chamber in which, according to the same principle as that of the air conditioning chamber (s) (5) and (7), the current air is brought into contact with a chemical agent and / or a gas used for the desired subsequent treatment of the culture in the shelter or in the greenhouse. Such an agent can be present either in liquid form, or in pulverulent form, or even in the form of gas. Such a chamber (9) may or may not be followed, depending on the physical state of the additive, by a separator (10) whose role is to eliminate the excess of the agent. This agent is of course admitted according to a determined quantity. This is the reason why the installation will include a "metering" system (14), the flow rate of which is itself automatically controlled by the control center (17) as a function of the air flow rate and the surface area of the plants. to be processed and parameters, previously determined by the user. In addition, the installation includes a station (11) (detail fig.4) d it for reading parameters in connection, on the one hand, with the greenhouse or shelter, and on the other hand, with all the stations previously described, so as to impose, by means of the control center (17), a running regime with conditions of temperature, rate of hygrometry, speed and press ion preset. This station is followed by a device called a valve (12) similar to the device (2) previously defined for directing, by means of a duct (13), the air conditioning and treated in a supply circuit of the different shelters or greenhouses not shown in Figure 1 according to a controlled regime depending on the number of greenhouses or shelters, their volume, the nature of the crop and the predetermined parameters specific to each crop and according to its stage of growth and evolution.

Referring to FIG. 2, this schematically represents a possible means for selecting the air intake in the installation, this means having been designated in the above description by "selector" (1) . It essentially comprises two ducts for the admission of air coming either from the inside of a shelter or a greenhouse (duct 1a), or from the outside (duct 1b). These ducts end up in a common pipe (1c) in direct connection with the ventilation group (4). A movable valve (1d) is rotatably mounted at (1e) with control (not shown). This command can be carried out either manually or under the automatic control of the control center (17), so as, depending on its position, to completely or partially block the air supply in one of the ducts (1a) or (1b ) according to criteria such as indoor or outdoor temperature, stage of cultivation, indoor or outdoor humidity (depending on whether it rains or sells). The inlet of each of the ducts (1a) - (1b) can advantageously be provided with appropriate filters (1f) according to the climatic conditions of the region in which the greenhouses or shelters are located. It will easily be understood that such filters are justified in particular in regions subject for example to trends in sandstorms.

With regard to the so-called air conditioning chamber (5), the purpose of which is to wash the air discharged by the ventilation unit (4), this may for example be of the type illustrated in FIG. 3 comprising ramps ( 5a) each provided with a series of nozzles such as (5b) directing jets of pressurized water in the opposite direction to the arrival of air (arrows A). This water is itself admitted into the ramps (5a) by one or more pipes such as (21-22) provided with solenoid valves (Ev1-Ev2). These pipes are themselves supplied by a pump (18) (see also FIG. 5 described below). The chamber (9) mentioned above, called the air treatment chamber, is designed in the same way as the chamber (5), with the difference that, in one of the conduits (such as 21 or 22) circulates the chosen treatment agent (additive suitable for the treatment of the culture) after dosing in the metering device (14) (FIG. 1).

The chamber (s) (5-9) are themselves each followed by a "separator" such as (6) (Figure 3) or (10) (Figure 1). In the case of the chamber (5), this separator is said to be a drop separator or "drop trap" of any known type which need not be described here in more detail. In the case of the treatment chamber (9), the purpose of such a separator is to eliminate the excess water and / or the quantity of the agent chosen when its content is above the desired quantity. There is shown in Figure 4, very schematically, a measuring box connected to the air outlet (arrow B). This box (11) comprises probes (T), (H), (D), (V) which are in connection with the control unit (17) to act on the air inlet selector (1), on the speed of rotation of the ventilation unit (4), on the pressure, on the solenoid valves (Ev1 - Ev2) depending on the temperature and humidity. This controls the parameters temperature, humidity, air flow, speed and pressure of this air in the greenhouse or shelters. These probes can be supplemented by others (X) giving the analysis of the treatment additive to also act on the flow rate or the dose thereof, whether in liquid, pulverulent or gaseous form. It is indeed known, in the field of culture, to use such products and such gases as for example CO ₂ . The water required for both the air conditioning chamber (5) and the treatment chamber (9) comes from any suitable source (natural or artificial water body, source, well, groundwater, etc.). This water is admitted (at E) into a tank (15) preferably located below the chamber (5). This tank is provided with an overflow (15a) and a drain (15b). In the vicinity of its bottom and near the inlet (E), it is advantageously provided with a filter (15c) in direct connection, via the appropriate pipe (15d), with the pump. (18) which is discussed above and feeding the ramp (21) or (22) corresponding. This tank is located below the chamber (5), the bottom (5c) of which is judiciously perforated to serve as a tank for collecting water that is not entrained and not evaporated in the installation (see FIG. 5). It will be the same for the treatment chamber (9) whose bottom will also be perforated to communicate with the tank (16) designed as the tank (15) and supplied with water loaded or not with additive. This tank (16) will be in direct connection with the corresponding pump (19) for the supply of the corresponding pipe (21) or (22), regulating the water flow in one and the other of the tanks (15 ) and (16). The installation may include, if necessary, a compartment (20) (see FIG. 1) for possible treatment of the water used therein. Of course, the water flow rates, the temperatures thereof are controlled by the control unit (17).

Referring to Figures (6) and (6a), there is also shown very schematically, a possible embodiment of the air distribution means inside a greenhouse. The air (B) coming from the assembly described above circulates in a main pipe (P) on which are connected, for each shelter or each greenhouse, ducts (G) judiciously arranged in these greenhouses or shelters, for example orthogonally by relative to the longitudinal axis of these rooms, as illustrated in the accompanying drawings. These sheaths have, on at least a portion of their external surface, preferably that directed towards the culture, a more or less fine mesh structure, so that the pressurized air which circulates there distributes regularly in the desired free volume without creating turbulence. The fineness of these meshes will be a function, if the air admitted is charged with a substance suitable for a specific treatment, the particle size of this substance to avoid any retention of the latter and, consequently, any unwanted clogging of the sheaths. As indicated previously, the greenhouses or shelters are maintained under pressure and they include probes such as (H) (for the hygrometric degree), (T) (for the temperature) as well as others, not shown for the clarity of the drawing. . In the event of overpressure, provision is made, for example on the ridge of these greenhouses or shelters, for a valve system, shown diagrammatically (in S) of any suitable type sensitive to variations in pressure and / or temperature. In any event, these greenhouses or shelters, maintained under a pressure higher than the pressure (S ') prevailing outside, will include on the gills (windows, doors, etc.) a pressure-sensitive valve system, so that in the event of opening, there is a shutdown of the installation for the admission of air conditioning air so as to avoid any phenomenon known as unwanted air flow. The installation will be able to start again at the time of the closing of these openings. It is not necessary to describe here the detail of these valve systems well known in the art as well as their mode of control or operation. These greenhouses may furthermore comprise at their upper part, preferably, and in association with these valve systems, systems (not shown) called "heat traps" allowing the recovery or storage of calories as soon as these greenhouses and their injection, by any appropriate circuit in their basements in direct, controlled and controlled communication with their substrates or their atmospheres.

The process and the installation which have just been described have the advantages which a person skilled in the art will immediately appreciate: A cultivation in greenhouses or shelters provided with an installation in accordance with the invention will lead to better quality production, thanks to the good air conditioning created by the implementation of the invention because plants - at no time undergo temperature differences or hygrometry, which generates better profitability by activating the chlorophyll function.

The invention also makes it possible to limit the spread of certain pests thanks to better humidity and the limitation of certain serious plant diseases thanks to the regular distribution of phytosanitary substances over the entire surface and over the whole extent of the crop. , while also allowing a significant saving on the purchase of such products which are expensive and dangerous, thanks to an appropriate dosage.

The invention also allows a supply of preset humidity on a large scale without the risk of wetting the plants and without increasing the amount of water in the soil, limiting the risk of frequent drenching which can, in some cases, suffocate the root system by excess water and the leaching of certain fertilizers or fillers. However, the necessary water supply to the roots and rootlets can be in controlled form through any suitable sensor.

Finally, the invention makes it possible to maintain a reasonable temperature at all times and it avoids burns on the foliage, burns which are frequent especially during the summer season. Maintaining the temperature of the substrate can also be achieved by recovering the calories mentioned above.

It goes without saying that the present invention has been described for purely explanatory and in no way limitative and that any useful modification can be brought there without going beyond its framework It is understood that an installation according to the invention can be autonomous and include its own energy sources and its safety groups for its proper functioning.

It goes without saying also that the method and the installations according to the present invention can be applied to all shelters, hangars, tunnels with an atmosphere which must be controlled and which can be used in other fields than cultivation such as, for example, the breeding of animals. Such a method and the associated installations could, of course, provide in combination with the means already used, suitable means for controlling the water content at ground level (substrate and the like).

Claims

1. Process for treating the atmosphere prevailing in greenhouses and other sheltered enclosures, characterized by the fact that it consists in taking air (1) which will be intended to create the atmosphere in the shelter or the greenhouse , selectively, inside or outside said room, subjecting this air to at least one filtration operation (3), at least one controlled humidification operation (5) comprising at least one extraction stage (6) of the liquid phase present in said air, at least one operation for adjusting the temperature of this air, to admit into the shelter or greenhouse the air thus treated (B) added or not agents suitable for a specific treatment of plants (9) according to a regular circulation mode such that it opposes any phenomenon known as air flow, while maintaining the internal atmosphere under controlled pressure, and if if desired, recover excess calories from this atmosphere for the purpose of reheating the soil or the subsoil. 2. Installation for implementing the above process, characterized in that it comprises: - a sampling and / or selection station (1) for the air to be admitted into the shelter or into the greenhouse, this selection being made on the air inside and / or outside said shelter; - a flow, speed and pressure adjustment station (11-17), for admitting said air thus withdrawn and selected; - a filtration station (2); - At least one air conditioning station (5) in which the air is subjected to a washing action with a view to giving it the desired level of hygrometry and bringing it to the desired temperature; - at least one air cleaning station thus washed to rid it of the excess liquid phase (6) which may be there, possibly followed by at least one air treatment station (9) by any agent suitable for an intervention specific to the crop in question; - at least one water withdrawal station (15-16) with its possible means of treatment before admission to the installation; - at least one general control station (17) for adjusting the temperature, the humidity level, the pressure, the flow rate, the speed, the content of specific treatment agent; - means for regular and uniform air distribution (PG) within the shelter or greenhouse, opposing the so-called air flow or turbulence phenomena, and finally, means for maintaining the atmosphere of the room under a uniform and constant pressure at a predetermined value in connection with the air intake and distribution circuit, and possibly means for recovering excess calories and injecting them into the ground or basement of said facility. 3. Installation according to claim 2, characterized in that the specific treatment agents are chemical agents (known for this use) in liquid, solid or gaseous form. 4. Installation according to one of claims 2 or 3, characterized in that it comprises, if desired, means for controlling the water content of the soil or the subsoil.