ES1301938U - An air conditioning system and an installation combining said system with a drying, granulating or coating apparatus in the field of pharmaceutical manufacturing (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

An air conditioning system (1, 1', 1'') to be used in a drying, granulating or coating process in the field of manufacturing pharmaceutical products, which comprises conducting means for conditioning air through means of dehumidification (11) and means of heating (21) of the dehumidified air, characterized in that - the conduction means are divided into a first unit (10) or air conduction module, which houses the means of dehumidification (11), and a second unit (20) or air conduction module, which houses the heating means (21) of the dehumidified air, the first and second units (10, 20) prepared to be coupled in series and give continuity to the air conduction; - the air conduction means also comprising a third unit (30) or air conduction module, which can be coupled between the first and second units (10, 20) giving continuity to the air conduction through the first, the third and second units (10, 30, 20), in this order; - The aforementioned third unit (30) comprising a heat recovery unit (31) of the gas-gas type with indirect contact through which the conditioned air is forced to circulate for its preheating, the third unit (30) being provided for this purpose. a hot inlet (30c) and a cold outlet (30d) for the recovery gas that is also forced to circulate through the heat recovery unit (31). (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

An air conditioning system and an installation combining said system with a drying, granulating or coating apparatus in the field of pharmaceutical manufacturing

Technical sector of the invention

The invention relates to an air conditioning system to be used in a drying, granulating or coating process in the field of manufacturing pharmaceutical products. The invention also refers to an installation that combines this air conditioning system with a drying, granulating or coating apparatus that uses the air conditioned by the system for its operation.

Background of the invention

The use of air conditioning systems is known in manufacturing processes of pharmaceutical products that make use of, or require, a flow of clean air and that also complies with certain humidity and temperature conditions. This air can be used, for example, to dry tablets freshly coated with liquid substances or to ensure uniform contact of granular products with liquid coating substances in fluidized beds.

A typical example of a coating apparatus that for its operation requires the supply of a dry air flow and a target temperature is described in the patent document US6511541.

Although the technical principle that these coating devices have been applying has not changed substantially for several years, it is true that they have been perfected in order to increase their operating efficiency.

Thus, for example, where previously these coating devices were dimensioned to work with batches of a specific size of articles to be coated, now these devices share the market with coating devices prepared to work with batches of various sizes. In this sense, the patent document EP3597048 discloses a coating device capable of directing and arranging a group of sprinklers in an ideal position. inside a perforated rotating drum, traversed by a flow of conditioned air, in which the articles to be coated are confined and agitated, being able to select the ideal position of the sprinklers according to the batch size of articles confined in the drum; and the patent document EP3903922 discloses a coating apparatus prepared to adjust and concentrate the outlet of the conditioned air passing through the drum, in coincidence with the part of the drum that is covered by the batch of articles confined in the drum.

This improvement in efficiency does not necessarily translate, or translates to a lesser extent than is desirable, in energy savings.

A first objective of the invention is an air conditioning system that, in combination with an appliance that uses or requires air conditioning by the system for its operation, leads to energy savings.

The invention also aims to offer a solution that is constructively versatile, that is, that it can be easily adapted to the specific requirements of each installation that needs an air conditioning system and that allows, for example, to reduce manufacturing and delivery times. of the teams.

On the other hand, facilities that incorporate devices of the type that use or require air conditioning flows produce used air, dirty due to having been in contact with liquid substances that contain active pharmaceutical ingredients, which must be treated for cleaning before being expelled. To the exterior. In addition to the applicable regulations or regulations regarding the cleaning of this dirty air, there may be other regulations or regulations of common application to industrial facilities that must be complied with, one of which deals with noise. For the aforementioned facilities, which have drying, granulating or coating devices, it is usual to have to incorporate silencing or noise attenuating devices that can cause the expulsion of the used air to the outside, after being cleaned.

Explanation of the invention

The proposed system is especially suitable for air conditioning to be used in a drying, granulating or coating process in the field of pharmaceutical product manufacturing.

The system comprises conduction means for conditioning air through dehumidification means and dehumidified air heating means and is essentially characterized in that the conduction means are divided into a first air conduction unit or module, which houses the dehumidification means; and a second air conduction unit or module, which houses the dehumidified air heating means, the first and second units being prepared to be coupled in series and give continuity to the air conduction.

The air conduction means of the system according to the invention are complemented by a third unit or air conduction module, which can be coupled between the first and second units, being able to continue the air conduction through the first, the third and the second units, in this order, the aforementioned third unit comprising an indirect contact gas-gas heat recovery unit through which the conditioned air is forced to circulate for its preheating, provided for this purpose the third unit of a hot inlet and a cold outlet for the recovery gas that is also forced to circulate through the heat recovery unit.

As explained in greater detail later, this partition allows a particularly advantageous modular construction of the system by adopting at least two different configurations: with and without the third unit.

As explained later, the system is designed so that the recovery gas is a flow of used air that comes from the air conditioning flow itself by the system of the invention after being used in an appliance that needs, for its operation, a airflow at certain target conditions.

In a non-deductible way, the interposition of the third unit between the first and second units not only allows preheating the conditioned air before being heated in the second unit, but it can also replace, or more comes, the need to have to equip to an installation, with a silencing or attenuating device for the expulsion noise of a used air flow. That is, the heat recuperator can display a suppressive effect on the exhaust noise of a used gas if it is precisely this that is used as recovery gas.

In a variant of the invention, the heat recovery is a cross-flow, hexagonal-type heat exchanger.

In a variant of the invention, the first, third and second air conduction units can be coupled in succession and on the same mounting plane. Preferably, the mounting plane is a vertical plane or a horizontal plane and advantage can be taken of selecting parallelepiped shapes for the first, second and third units, facilitating their coupling and optimizing their spatial arrangement.

In a variant, the space surrounding the heat recovery unit in the third unit is compartmentalized, alternating around the heat recovery unit and in the assembly plane a compartment in communication with an air intake to be preheated from the heat recovery unit, a compartment into which it opens. an air inlet to be preheated from the third module connectable to a dehumidified air outlet from the first module when said first and third modules are mutually coupled; a preheated air compartment in communication with a preheated air outlet from the heat recovery unit, a compartment opening to a preheated air outlet of the third module connectable to a preheated air inlet of the second module when said second and third modules are mutually coupled ; a compartment in communication with an intake of air to be preheated from the heat recovery unit into which a hot air intake from the third module enters; and a compartment in communication with an outlet for cold recovery gas from the heat recovery unit that opens with a cold outlet from the third unit.

When the mounting plane is a vertical plane, preferably the air inlet to be preheated is formed in the third unit to be located at a level above the preheated air outlet; and the hot recovery gas inlet is formed to be located at a level above the cold recovery gas outlet.

Among other advantages, this allows the compartment in communication with the expulsion of cold recovery gas from the heat recovery unit to house an auxiliary condensate collector, located in the vertical projection of said expulsion of cold recovery gas from the heat recovery unit.

When the assembly plane is a vertical plane, the system is expected to include a recovery gas evacuation box that can be coupled to the cold recovery gas outlet of the third unit and dimensioned, at least in width, according to the first unit. , serving as support for the aforementioned first unit.

When the mounting plane is a horizontal plane, it is envisaged that the system comprises a recovery gas evacuation box that can be coupled to the recovery gas cold outlet of the third unit and configured to be then juxtaposed to the first unit.

In a variant, the dehumidification means housed in the first unit comprise first filter means, a cooling coil and a condensate collector.

In a variant, the heating means comprise a delivery fan, a steam coil and second filter means.

According to another aspect of interest, an installation is disclosed that combines an air conditioning system according to the present invention with a coating, spraying or drying apparatus to which an operating air flow is supplied and a used air flow is returned, wherein this operating airflow contains air conditioned by the system and wherein the recovery gas used by the system contains used air.

The invention takes special advantage of devices that do not have, or have limited, capacity to regulate the air flow to be used and that do not use all the conditioned air for their operation, this unused air losing little calorific value.

Then, in a variant of the installation, it comprises a bypass branch at the entrance of the apparatus and the recovery gas used by the conditioning system comes from a mixture that contains air used by the apparatus and air bypassed by the bypass branch, not used by the device.

Brief description of the drawings

Fig. 1 schematically shows an air conditioning system according to a variant of the invention, in side elevation;

Fig.2 shows an air conditioning system according to another variant of the invention, in this case in plan;

Fig. 3 shows an installation combining an air conditioning system, according to the variant illustrated in Fig. 1, with a coating apparatus;

Fig. 4 shows another installation that combines an air conditioning system, according to the variant illustrated in Fig. 1, with a drying apparatus.

Detailed description of the invention

In Fig.1 an air conditioning system 1 according to a variant of the invention is shown.

The system 1 comprises a first air conduction unit 10; a second air conduction unit 20; and a third air conduction unit 30.

The units 10, 30 and 20 are coupleable and in Fig. 1 they are coupled in succession, in such a way that they form a passage for air to be conditioned that will pass through these units, entering through an intake mouth 10a of the first unit. 10 and exiting through an expulsion mouth 20b of the second unit 20 with connection means to an air conduit of a facility, this air having passed to be conditioned through the third unit 30.

In the example, the first, second and third units 10, 20 and 30, respectively, have an essentially parallelepiped shape and form a kind of part of a modular system in which the first and second units 10 and 20 can be coupled in succession. without interposition of the third unit 30; or alternatively the first unit 10, the third unit 30 and the second unit 20 can be coupled in succession.

The first unit 10 is prepared to dehumidify the air that passes through it, for which it houses dehumidifying means 11. In the example, the main components of these dehumidifying means 11 are first filter means 12, comprising a set of a first filter G4 for coarse dust and a second filter type F9 for fine dust according to the European standard EN 779; a refrigeration battery 13, sized to cool the air being conditioned to the dew point, which causes its loss of humidity; and a condensate collector 14, in the form of a condensate tray, which collects the water that precipitates from the conditioned air after cooling.

A refrigeration battery is understood to mean any medium that produces a heat exchange between the air being conditioned and a cold medium, sufficient to dehumidify the air being conditioned at working pressure.

The third unit 30 is prepared to preheat the air that passes through it, for this it houses a gas-gas type heat recovery unit 31 with indirect contact through which the conditioned air and a recovery gas are forced to circulate.

In the example, the heat recovery unit 31 is a cross-flow plate heat exchanger. The heat transfer is carried out through the multiple layers that are housed inside the heat recovery unit 31 and arranged in such a way that the fluids, in this case the conditioned air and the recovery gas, do not come into direct contact. , since their respective circuits are completely independent. For this purpose, the third unit 30 includes a hot inlet 30c for the recovery gas that has connection means to a recovery gas line and opens into a compartment of the third unit 30, a compartment in communication with an intake of the heat recovery 31; and a cold outlet 30d for cold recovery gas into which another compartment of the third unit 30 opens, a compartment in communication with an outlet for recovery gas from the heat recovery unit 31.

Of course, other candidates for the heat recuperator 31 are possible.

For its part, the second unit 20 is prepared to heat the air already dehumidified by the first unit 10 and preheated by the third unit 30, which passes through it, for which it houses heating means 21. In the example, the Main components of these heating means 21 are a supply fan 22, which drives or forces the air to advance through the system 1; a steam battery, sized to heat the preheated air in the third unit 30 to a target temperature, necessary to carry out a process that will use the air conditioning, as will be explained in greater detail later; and a second filter means 24, comprising a H13 absolute HEPA filter according to the European standard EN 779.

A steam battery is understood as any medium that produces a heat exchange between a gas, preferably steam, and the air being conditioned.

In the example of Fig. 1, the air conditioning system 1 has a configuration in which the first unit 10, the second unit 20 and the third unit 30 are coupled in a same vertical mounting plane.

In the aforementioned example, the third unit 30 has a dimension in height similar to the sum of the first and second units 10 and 20 and the hot inlet 30c and the cold outlet 30d of the recovery gas are located diagonally opposite, the inlet being hot 30c at a higher level and cold outlet 30d at a lower level.

The first unit 10 and the third unit 30 are prepared for their mutual coupling to give continuity to the conduction of the conditioned air throughout the system 1, in this case they are sized and/or prepared so that a dehumidified air outlet 10b from the The first module 10 connects with an air inlet to be preheated 30a of the third module 30 that opens into a compartment in communication with an air inlet to be preheated in the heat recovery unit 31.

In a similar way, the second unit 20 and the third unit 30 are also prepared for their mutual coupling to give continuity to the conduction of the conditioned air throughout the system 1, in this case they are dimensioned and/or prepared so that an outlet of preheated air 30b of the third module 30, which opens into a compartment in communication with an expulsion of preheated gas from the heat recovery unit 31, connects with a preheated air inlet 20a of the second module 20.

Notice that in the example of Fig. 1, the air inlet to be preheated 30a and the air outlet for preheated air 30b are located diagonally opposite, the air inlet to be preheated 30a being at a higher level and the air outlet for preheating 30b at a higher level. lower.

Likewise, the third unit 30 comprises, in the example, separate partitions 32 and 33 to compartmentalize the room and prevent the mixing of the air in conditioning and the recovery gas in the containment space of the heat recovery unit 31.

However, adopting the arrangement shown in Fig. 1, an air conditioning circuit is formed in which the flow of air to be conditioned circulates, from left to right according to the orientation of the drawing, along the first unit 10 following an essentially horizontal direction, it circulates through the third unit 30, crossing the heat recovery unit 31, following a direction with a downward component and circulates along the second unit 20 following an essentially horizontal direction until leaving the second unit 20 In this system 1, the recovery gas will circulate through the third unit 30, passing through the heat recovery unit 31, following a substantially normal direction with respect to the direction that the conditioned air follows through this same third unit 30.

This particular arrangement is advantageous, for example, to locate an auxiliary collector 34 of condensate at the lower level of the third unit 30, specifically in the compartment where the expulsion of cold recovery gas from the heat recovery 31 is located. In the example , this auxiliary manifold 34 is positioned in the vertical projection of said expulsion of cold recovery gas.

The inclination to which the heat recuperator 31 is solidly attached in the third unit 30 favors the discharge by gravity of this recovery gas condensate.

In the example of Fig. 1, the system 1 comprises a box for evacuation 40 of the recovery gas. This evacuation box 40 and the third unit 30 are also prepared for their mutual coupling to give continuity to the conduction of the recovery gas through the system 1, in this case they are dimensioned and/or prepared so that the cold outlet 30d of the gas of cold recovery of the third module 30 connect with an inlet of cooled recovery gas 40a of the evacuation box 40.

The recovery box 40 is particularly dimensioned according to the first unit 10, at least in width, serving as a support for it.

The evacuation box 40 includes an outlet for the recovery air 40b of the system 1 that mounts connection means to a cold gas pipe of the installation.

In Fig. 2 an air conditioning system 1' according to another variant of the invention is shown, similar to the system 1 of Fig. 1 except that the first, third and second units 10, 30 and 20, respectively, air ducts are successively coupled on the same now horizontal mounting plane.

In the system 1' of Fig. 2, the same numerical references as in Fig. 1 have been used to designate equivalent components, only the main components and/or means having been indicated.

By adopting the system 1' the layout shown in Fig. 2, an air conditioning circuit is formed in which the air flow to be conditioned circulates, from left to right according to the orientation of the drawing, along the first unit 10 following an essentially horizontal direction, it circulates through the third unit 30, passing through the heat recovery unit 31, following an essentially horizontal direction but at an angle to the direction that the conditioned air followed along the first unit 10, and circulates along the second unit 20 following an essentially horizontal direction parallel to the direction that the conditioned air followed along the first unit 10. In this system, the recovery gas circulates through the third unit 30, passing through the heat recovery unit 31, following a substantially normal direction with respect to the direction that the conditioned air follows through this same third unit 30.

Fig. 3 illustrates an installation 100 combining an air conditioning system according to the invention, for instance a system 1 according to Fig. 1, with a coating apparatus 101.

The coating apparatus 101 is of the type comprising a container within which a drum containing a production batch of articles to be coated is rotated. For this purpose, the apparatus is equipped with means for spraying the product to be used to coat said articles. This spraying operation is carried out while the drum rotates and stirs the batch of articles to provide a homogeneous coating on all articles. In a known manner, the drum is perforated and the coating apparatus comprises a forced gas circuit, which passes through the drum and helps the sprayed product to dry once it has been applied to the articles to be coated.

It is particular to this installation 100 that the forced gas used in the coating apparatus 101 is the air conditioned by the system 1; and that the recovery gas used by the system 1 is the air resulting from operating the coating apparatus 101.

The installation 100 is exemplified starting from an intake of outside air that is fed to the system 1 through the intake mouth 10a of the first unit 10, air that we are going to assume at around 10°C and with a determined humidity, in this case , 90% RH (the expert will understand that these conditions will depend in each case on the atmospheric conditions) with the system 1 configured to condition this captured air so that it meets specific conditions of clean, dry air and at a target temperature that for the example case is selected from 65°C, optimal conditions for its use in the apparatus 101 of the installation 100.

In support of Fig. 3, this air captured from the outside passes through the dehumidification means 11, for that matter and in this order the coarse dust filter, the fine dust filter and the refrigeration coil, obtaining at the outlet of the first unit 10 dehumidified air from which approximately 98% of its impurities have been extracted and which will have a temperature of approximately 7-9°C, when the target temperature is 65°C (which means a thermal jump of 58° C).

In order to condition the air and raise its temperature up to the target 65°C, the installation 100 takes advantage of the residual heat of the air that results from operating the coating apparatus 101 and the system 1 will heat the conditioned air in two stages: in the first , which is carried out in the third unit 30 of the system 1, transferring to it heat from the used air that results from operating the coating apparatus 101; and in the second, which is carried out in the second unit 20 of system 1, using the aforementioned heating means 21.

In the installation 100, the coating apparatus 101 is also of the type capable of optimizing its operation according to the size of the batch of articles to be coated. To this end, the coating apparatus 101 can incorporate technology to arrange and orient the ejectors of the product to be sprayed at an optimal distance from the free surface of the articles in the drum and/or to regulate and concentrate the outlet of the drying air that passes through the drum in coincidence with the wall of the same covered by the articles. Technological proposals in this sense is disclosed in the patent documents EP3597048 and EP3903922 respectively.

This ability to regulate the operating parameters of the coating apparatus 101 depending on the size of the batch of items to be coated arouses interest in also being able to select the air flow rate that must pass through the drum.

However, with the range of this item lot size variability for which the coating apparatus 101 is capable of being parameterized from 10% to 100% of the possible load, it may be the case that the airflow variability that corresponds to each batch size cannot be assumed by the frequency inverters or, ultimately, by the air supply equipment. In this regard, it is of interest that the installation 100 proposes to equip it with a bypass branch 102 and with associated valve means 102a for diverting the air conditioning flow that is conducted to the coating apparatus 101 through the air conditioning conduction. 105, the excess air flow that should not be fed to the coating apparatus 101, especially when operating with small batch sizes. This excess air flow comes from system 1 and is, therefore, a clean air flow that will retain its temperature to a greater extent compared to the air flow that passes through the drum of the device 101 and is used in the process of covering.

In the installation 100, the used air returned by the apparatus 101, which is dirty, humid air (conditions of 80% RH can be approximated) and which will have an approximate temperature of 40-45°C, is mixed with the air conditioning bypassed. . For this purpose, the installation comprises a used air line 103 connecting the outlet of the coating apparatus 101 with a mixer 104, downstream of the valve means 102a.

Although the temperature of the dirty air may vary depending on the type of appliance and the needs of the installation, the approximation of 40-45°C indicated above will serve to exemplify the invention.

In the exemplary installation 100, the mixture of bypassed air conditioning and used air is introduced via an interconnecting line 109 to a dust collector 106, where the mixture is cleaned of impurities from the coating apparatus 101. The dust collector 106 can be equipped, for example, with filters of type F9 and H13.

Drive means 107 will drive the clean air, which will now play the role of recovery gas, through a recovery gas line 108 to the hot inlet 30c of the third unit 30 of the air conditioning system 1.

The intervention of the heat recovery unit 31 in the third unit 30 will make it possible to transfer heat from the air used, in humid conditions and at a temperature of 40-45°C, or higher depending on the ratio of air passed through, to the air dehumidified that serves the first unit 10 preheating the latter before entering the second unit 20.

In this case, the heat recovery unit 31 is adapted to the characteristics of the recovery gas used. For example, it is of the type constructed with epoxy bonded exchange plates to prevent oxidation with the moisture charge of the recovery gas.

Practice has made it possible to experience increases in the temperature of the dehumidified air that will go from 7°C (at the inlet of the third unit 30) to approximately 39°C (at the outlet of the third unit 30). Consequently, the thermal jump that the heating means 21 of the second unit must provide when the target temperature is 65°C will only be 26°C (when this jump was 58°C in the absence of the third unit 30). with the consequent energy savings that this entails.

Practice has shown fuel reductions, for example from using oil fired steam boilers to operate the air conditioning system steam coil, of about 50% when the coating apparatus 101 works with small batch sizes and of approximately 45% (due to a steam saving that can be of the order of 55%) when the coating apparatus 101 works at maximum load.

Fig. 4 illustrates an installation 100' combining an air conditioning system according to the invention, in this case a system 1'' very similar to that of Fig. 1, with an appliance 101' which in this case is an appliance fluidized bed drying.

The system 1'' lacks air conditioning drive means and the air flow used by the installation is driven by the suction carried out by a centrifugal fan 22' which is located downstream of the apparatus 101'.

The air conditioned by the system 1'' and that is supplied to the apparatus 101' will have conditions similar to the air that was supplied to the apparatus 1 in the installation of Fig. 3. In the drying apparatus 101', the air is in charge of to dry a granulated product in suspension with a liquid substance (or even, if required, to ensure its correct granulation).

As in installation 100, in installation 100' the used air can be mixed at the outlet of the apparatus 101' with bypassed air and in this case the mixture is passed through a dust collector 106' that has dust filters fine and H13 absolutes, where the mix is thoroughly cleaned. The resulting air, humid and hot, will play the role of recovery gas in the system 1'' to preheat the dehumidified air produced by the first unit 10, through the heat recovery unit 31 in the third unit 30, before being heated in the second unit 20, all in a similar way to what happened in the installation 100 of Fig. 3.

Claims (13)

1. - An air conditioning system (1, 1', 1'') to be used in a drying, granulating or coating process in the field of manufacturing pharmaceutical products, which includes air conduction means in conditioning through means of dehumidification (11) and means of heating (21) of the dehumidified air, characterized in that - The conduction means are divided into a first unit (10) or air conduction module, which houses the dehumidification means (11), and a second unit (20) or air conduction module, which houses the dehumidification means. heating (21) of the dehumidified air, the first and second units (10, 20) prepared to be coupled in series and give continuity to the air conduction; - the air conduction means also comprising a third unit (30) or air conduction module, which can be coupled between the first and second units (10, 20) giving continuity to the air conduction through the first, the third and second units (10, 30, 20), in this order; - The aforementioned third unit (30) comprising a heat recovery unit (31) of the indirect contact gas-gas type through which the conditioned air is forced to circulate for its preheating, the third unit (30) provided for this purpose with a hot inlet (30c) and a cold outlet (30d) for the recovery gas that is also forced to circulate through the heat recovery unit (31). 2. - A system (1, 1', 1'') according to the preceding claim, characterized in that the heat recuperator (31) is a hexagonal-type cross-flow heat exchanger. 3. - A system (1, 1', 1'') according to any one of the preceding claims, characterized in that the first unit (10), the third unit (30) and the second air conduction unit (20) are can be coupled in succession and on the same mounting plane. 4. - A system (1, 1', 1'') according to the preceding claim, characterized in that the space surrounding the heat recuperator (31) in the third unit (30) is compartmentalized, alternating around the heat recuperator (31 ) and in the assembly drawing - a compartment in communication with an air inlet to be preheated from the heat recovery unit (31), a compartment into which an air inlet to be preheated (30a) from the third module (30) connectable to a dehumidified air outlet (10b) of the first module (10) when said first and third modules are mutually coupled; - a preheated air compartment in communication with a preheated air outlet from the heat recovery unit (31), a compartment opening to a preheated air outlet (30b) of the third module (30) connectable to a preheated air inlet (20a) of the second module (20) when said second and third modules are mutually coupled; - a compartment in communication with a hot recovery gas inlet of the heat recovery unit (31) into which the hot inlet (30c) of the third module (30) opens; and - a compartment in communication with an outlet for cold recovery gas from the heat recovery unit (31) that opens with the cold outlet (30d) of the third unit (30). 5. - A system (1, 1'') according to the preceding claim, characterized in that the mounting plane is a vertical plane, with the air inlet to be preheated (30a) at a level above the preheated air outlet ( 30b); and the hot inlet (30c) of recovery gas at a level above the cold outlet (30d) of recovery gas. 6. - A system (1, 1'') according to the preceding claim, characterized in that the compartment in communication with the expulsion of cold recovery gas from the heat recovery unit (31) houses an auxiliary condensate collector (34), located in the vertical projection of said expulsion of cold recovery gas from the heat recovery unit (31). 7. - A system (1, 1'') according to the preceding claim, characterized in that it comprises an evacuation box (40) of the recovery gas that can be coupled to the cold outlet (30d) of recovery gas of the third unit (30). and dimensioned according to the first unit (10), serving as a support for said first unit (10). 8. - A system (1') according to claim 4, characterized in that the assembly plane is a horizontal plane and that the system comprises an evacuation box (40) of the recovery gas that can be attached to the cold outlet (30d) of gas recovery of the third unit (30) and configured to be then juxtaposed to the first unit (10). 9. - A system (1, 1', 1'') according to any one of the preceding claims, characterized in that the dehumidification means (11) housed in the first unit (10) They comprise first filter means (12), a cooling battery (13) and a condensate collector. 10. - A system (1, 1') according to any one of the preceding claims, characterized in that the heating means (21) comprise a supply fan (22), a steam battery (23) and second filter means (24). 11. - An installation (100, 100') that combines an air conditioning system (1, 1', 1'') according to any one of the preceding claims with an apparatus (101, 101') for coating, spraying or drying to which an operating air flow is supplied and a used air flow is returned, in which this operating air flow contains air conditioned by the system (1, 1', 1'') and in which the recovery gas used by the system (1, 1', 1'') contains used air. 12. An installation according to claim 11, characterized in that it comprises a bypass branch at the input of the apparatus (101, 101') and that the recovery gas used by the system (1, 1', 1'') comes from a mixture of the air used by the apparatus (101, 101') and the air bypassed by the bypass branch. 13. An installation according to claims 11 or 12, characterized in that it is devoid of a silencing device for the air flow used by the apparatus (101, 101').