Abstract:
The invention relates to a method for treating products with air in order to enable the conservation, storage and use thereof. Said invention also relates to a device for treating such products and the products obtained using said treatment method. The products (P) to be treated, such as a hay drier or other similar agricultural products, are loaded into a closed space ( 20 ) that is connected to a thermodynamic machine ( 21 ) which is controlled using a programmable automaton ( 22 ) and which is powered by an electrical cabinet ( 25 ). Three mass of water in air sensors (Q 1 , Q 2  and Q 3 ) determine the operation of the machine according to the desired treatment objectives both in terms of moisture in relation to the product treated and power consumption. The invention is suitable for treating diverse products such as agricultural products.

Description:
TITLE OF THE INVENTION 
   BACKGROUND OF THE INVENTION 
   The present invention relates to a process for the treatment of products with air so as to permit particularly their preservation, their storage and their use. It also relates to a device for treatment of such products and the products obtained by the treatment process. 
   DESCRIPTION OF THE RELATED ART 
   In the field of livestock feed, it has long been known to prepare fodder from various fodder plants that are cultivated for this purpose. The mature plants were gathered at harvest time and transferred into silos to dry in free air during the last days of summer. Suitably dried, the fodder was preserved for all the season in the course of which the fields no longer supplied enough plants and grass to permit raising livestock. But the drying techniques used a source of heat (sun or heater) for drying hay to promote the evaporation of the water it contains. However, the heating gives rise to a loss of quality of the fodder and more generally the treated products, and the energy cost is fairly often too high. 
   With more recent industrialization of agriculture in general and under the constraint of requirements of economic origin in the broadest sense, this mode of heating has been in competition with and often has been completely replaced by the use of replacement food such as food in the form of granules and above all animal farinas which have been seen to be catastrophic both for the effects on the livestock and on the public health. 
   However, the return of ancestral techniques for treating fodder is no longer to be considered. 
   Moreover, numerous agricultural activities are treated by industry particularly for the packaging of grains (cereal harvest) in silos particularly which permit preserving the harvest sold to farmers before resale during subsequent periods. However, this economic added value is justified only by treatment means that the agricultural industry uses. 
   As a result of the above, there exists a need to treat the harvest such that it will be reusable later in each agricultural employment or more generally in the industry using treated agricultural products. 
   SUMMARY OF THE INVENTION 
   To this end, the invention relates to a process for treatment of products with air treated by means of a thermodynamic treatment machine, which consists:
         in calculating the operating regime of the thermodynamic treatment machine defined by an assembly of predetermined values of parameters of operating comprising:
           the operative condition of power driven fans driving air to be treated by the treatment machine;   the condition of opening access registers of air to be treated by the treatment machine;   the operative condition of the compressor or compressors of the treatment machine;   the switching condition of a reversing valve reversing the operation of the thermodynamic treatment machine;   the weight of the products to be treated;   a weight of water Qtheo to be extracted per unit time, said mass use of Qtheo being determined by:   the nature of the products to be treated;   the desired duration of treatment;
 
for a treatment object predetermined by a combination of at least:
   
           a criterion of quality of treatment measured on the products as the quantity of dry material;   a duration of treatment;   an electrical consumption of the treatment machine;   an economic cost;   in loading into a receptacle at least partially closed a load of products to be treated;   in removing at most a fraction of air from the load of products and, as the case may be, mixing it with the external air;   controlling the flow rate, the temperature and/or the quantity of saturating steam of the treated air so as to produce a treated airflow, such that there will be applied a dehumidification treatment, of dehumidifying, heating and/or cooling the treatment air; and   reinjecting at least a portion of the treated airflow into the load;
 
and applying the treatment at least to the extent that the treatment objective is not achieved for at least one assembly of predetermined values of the operating parameters.
       

   The invention also relates to a treatment device for products using the process of the invention. 
   The invention also relates to products treated by the device of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other characteristics and advantages of the present invention will become better understood from the help of the description and the accompanying drawings, wherein 
       FIG. 1 : a block diagram of an essential portion of the device of the invention; 
       FIG. 2 : a block diagram of an embodiment of the, treatment device using the process of the invention; 
       FIG. 3 : a diagram representing the sequence of thermodynamic conditions of a device operating according to the process of the invention; 
       FIG. 4 : a block diagram of a portion of the device of the invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  shows a block diagram of an essential portion of the device of the invention in one embodiment. This essential portion comprises a thermodynamic machine for treatment of air. The latter comprises, in a sealed cabinet  1 , a plurality of compartments  2 – 5  in which the air to be treated circulates between two access doors  6  and  12 . The machine for treating air of the device of the invention operates with airflows which can proceed:
         from the door  6  to the door  12 ;   from the door  12  to the door  6 ; and   in two directions between the doors  6  and  12 .       
   The sealed cabinet  1  also comprises a series of registers  13 – 16  which permit with the help of flap diaphragms, for example each register being mobilized by an actuator (not shown) controllable from a central automaton (not shown in  FIG. 1 ), regulating the introduction or expulsion of external or ambient air, or else the air from a receptacle containing the products to be treated, such as agricultural products, such as grain or fodder. The registers  13 – 16  also permit adjusting the airflow rates and pressures in the treatment machine. 
   The two end compartments  2  and  5  comprise respectively an evaporator-condenser device  7  and an evaporator-condenser device  11 . In the partition separating the compartment  7  in which has been disposed the evaporator-condenser  7 , and the other internal compartment (here shown at  3 ), there is mounted the battery  8  of the evaporator-condenser  7 . In the partition separating the compartment  5  in which has been disposed the evaporator-condenser  11 , and the other internal compartment (here shown at  4 ), there is mounted the battery  10  of the evaporator-condenser  12 . 
   Each evaporator-condenser coacts with a power-driven fan comprised by a centrifugal fan and an electric motor whose operation is controlled by a central automaton (not shown in  FIG. 1 ). The evaporator-condenser also comprises a battery for heat exchange with the air in the course of treatment. Each battery is thus constituted by a serpentine coil in which circulates a heat transfer fluid and against which the air in the course of treatment circulates. According to whether the evaporator-condenser works as an evaporator or as a condenser, the battery is either warmer than the air in the course of treatment or colder than the air in the course of treatment. As can be seen from  FIG. 4 , these two batteries comprised each of a heat exchanger are connected between themselves and with other components by a fluid circuit traversed by a heat transfer fluid such that the airflow which passes through each of the exchangers exchanges thermal energy with the fluid circuit. 
   In the embodiment of  FIG. 1 , the cabinet  1  also comprises a partition separating the two central compartments  3  and  4 . The partition separating these two central compartments is provided with a register, called register C, comprising a diaphragm with flaps, remotely controlled by an actuator (not shown in  FIG. 1 ) and which is maneuvered under the control of the central automaton mentioned above (not shown in  FIG. 1 ). 
   In this embodiment, the central compartments are provided with at least one register  14  and preferably two registers  14  and  15 , each comprising a diaphragm with flaps remotely operable by an actuator (not shown in  FIG. 1 ) and which is maneuvered under the control of the central automaton mentioned above (not shown in  FIG. 1 ). 
   In what follows, each register of the device for treatment of the invention is designated by:
     “A” register  13  on the compartment  2  of the power-driven fan  7 ;   “B” register  14  on the compartment  3  supporting the battery of the first evaporator-condenser  8 ;   “C” register  9  between the two central compartments  3  and  4 ;   “D” register  14  on the compartment  4  supporting the battery of the second evaporator-condenser  10 ;   “E” register  15  on the compartment  5  of the power-driven fan  11 .   

   To control the operation of the device of  FIG. 1 , there is shown in  FIG. 2 , the assembly of the device for practicing the process of the invention. In  FIG. 2 , a treatment receptacle or volume  20  is loaded into a base zone P with a predetermined quantity of agricultural products to be treated. From an upper portion A is provided in the closed treatment volume  20  in which circulates a mixture of air from the thermodynamic treatment machine  21  and the air from the mass of the agricultural products to be treated P. Such a closed volume  20  for treatment can be a crop dryer. 
   The atmosphere of the closed volume  20  is communicated to the thermodynamic machine for treatment by two passages for air to be treated  23  and treatment air  24 . According to the treatment applied according to the process of the invention, which will be described later, one or the other of the two passages  23  and  24  is connected:
         to the door  6  and the door  12 ;   to the door  12  or the door  6 ; or   in both directions to the doors  6  and  12 .       

   In one embodiment, the passageway  23  for recycling is omitted and the door  6  of the sealed cabinet  1  is directly supplied with external air. In this case, the treatment machine  1  blows treatment air from the door  12  through the passage  24  and external air is sucked in through the door  6 . 
   The thermodynamic machine  21  for treatment of air and its registers A, B, D and E can also be connected to the external air by a passage  29  which, in the embodiment of  FIG. 2 , permits supplying each of the four registers. In another embodiment, only certain ones of the registers are connected to the passage  29 . In another embodiment, certain of the registers are connected independently to the external air by its own passage  29 . 
   The thermodynamic machine  21  for treatment of air and its registers A, B, D and E can also be connected to the closed volume  20  by a passage  29 ′ which, in the embodiment of  FIG. 2 , permits each of the four registers to exchange airflow with the closed volume. In another embodiment, only certain of the registers are connected to the passage  29 ′. In another embodiment, certain ones of the registers are connected independently to the closed volume  20  by its own passage  29 ′. 
   When a register A, B, D or E is connected both to the passage  29  to external air and to a passage  29 ′ with the closed volume  20 , it can comprise two diaphragms with separate flaps with their own actuator controlled independently by the central automaton  20  which is a commercially available programmable automaton. 
   The connection of the principal passages  23  and  24  and of registers  29 ′ to the closed volume can take place according to at least two embodiments. In a first embodiment, the airflow for treatment from the treatment machine  21  passes through the thickness of the products to be treated. Because of this, the passage connections for blowing treatment air and the passage connections for sucking in air to be treated are disposed on opposite sides of the product P to be treated, each at one or several points according to the treatment circumstances. In a second embodiment, the product P to be treated is bathed in its own atmosphere in the closed volume  20  and the treatment of the invention is applied to this atmosphere. The connections of the principal passages  23  and  24 , and  29 ′ of the registers are thus disposed in opposition in the atmosphere which bathes the product to be treated. 
   As will be seen later on, a passage  29 ′ connected to a predetermined register A, B, D or E can be connected, not to the closed volume  20 , but to an energy recovery module. 
   The device of the invention also comprises two or three detectors to determine the quantity of water vapor in the air which passes through the thermodynamic machine. These detectors measure respectively:
     Q 1 : the quantity of water vapor contained in the air from at least one closed volume  20  in which are located the agricultural products P to be treated;   Q 2 : the quantity of water vapor contained in the external air both in the closed volume  20  in which the agricultural products P to be treated are located and in the thermodynamic machine  21  in which are disposed the treatment compartments of the air described in  FIG. 1 ;   Q 3 : the quantity of water vapor contained in the air from the outlet of treatment through door  6  or  12  according to the direction of operation of the thermodynamic machine  21 .   

   In the embodiment in which the passage  23  is missing, it is unnecessary to have a detector Q 1  to measure the content of water in the air at the outlet of the closed volume  20 . 
   The three detectors of the quantity of water in the air, Q 1  to Q 3 , have output terminals which give electrical signals whose voltage is representative of the instantaneous measurement of the quantity of water in the air to which they pertain. These signals are transmitted by suitable means to the input terminals for measuring signals of the quantities of water in the air to control the operation of the device of the invention, which terminals are disposed on the mentioned control automaton  22 . 
   The control automaton  22  comprises a treatment module  26  for the signals of measurement Q 1  to Q 3  whose outputs are communicated with a central processor  27  in which is executed a control program such that the process of the invention will be performed. The processor  27  activates as a function of the process of the invention an assembly  28  of modules which produce control signals which are respectively:
         an actuating control module associated with each register A to E and which configures a control parameter of the condition of opening or closing, proportional or all or nothing according to the circumstances;   a control module for power-driven fan  7 ,  11  associated with each evaporator-condenser and which configures a control parameter of the operating condition of the motor, proportional or, preferably, all or nothing according to the circumstances;   a control module associated with each remotely controllable component of the fluid circuit which constitutes the thermodynamic machine for processing air which connects the batteries  8  and  10  of which one works as the evaporator and the other as the condenser and which will be described later.       

   The assembly  28  of the control modules of the programmable automaton  22  is electrically connected to an electrical supply cabinet  25  such that the control of the electrical consumption can be processed directly by the program executed by the processor  27 . The criteria for management of electrical consumption take account of the electrical supply source, particularly the classes of frostiff as a function of the time or more generally of the date such that as a function of the desired economic efficiency of the treatment of agricultural products, the parameters of operation to control the treatment machine of the air will be determined to achieve the predetermined treatment objectives as a function of the determined values of the quantities Q 1  to Q 3  of water in the air in the course of the fixed duration of treatment. 
   In one embodiment, the control automaton  22  also comprises a remote surveillance means T 1 , T 2  which comprises principally:
         a module T 1  adjacent the automaton which comprises a circuit to detect the values of parameters of operation of the machine and particularly the measurements Q 1  to Q 3  of the quantities of water in the air, the condition of operation of the fans and of the compressors of the thermodynamic machine, the condition of opening of the registers, the electrical consumption, etc., a circuit to detect the alarm values of the values detected of the parameters of operation, at least one alarm value is reached, a circuit to transmit the assembly of the instantaneous values and/or a history of this assembly over a predetermined period, a circuit to receive the values of control parameters and standard values brought up to date such that the operation of the device will be changed;   a module T 2  disposed remotely and which comprises a circuit to receive data from the module T 1  and particularly an alarm signal, and a history of the values and parameters of operation of the machine, a circuit to determine as a function of the received values of the parameters of operation of the machine, new reference values and/or control values for the parameters of operation of the machine,   a specialized connection between the modules T 1 , T 2 .       

   With this remote surveillance means, it is possible that the machine will thus be able to be adapted as a function of accidental circumstances signaled by the alarms. 
   In one embodiment, the control automaton  22  also comprises a means to detect a situation of formation of frost on a cold battery or one of the two evaporator-condensers of the thermodynamic machine. The battery susceptible to the formation of frost obtained by accumulation of water in the form of solids extracted from the air in the course of treatment, comprises a temperature detector which detects that the cold battery has reached a temperature near the temperature of formation of frost, namely 0 to 4 degrees Celsius. The automaton  22 , detecting this reference temperature, produces a control signal destined for the thermodynamic machine to reverse the operation of the thermodynamic machine so as to cause to pass it into a heating mode of its heat exchange fluid during a predetermined period or until the temperature of the cold battery rises to a predetermined value ensuring the disappearance of the frost, as will be described later with the help of  FIG. 4 . 
   In one embodiment, a pressure detector is disposed in the passage of access to each battery of the evaporator-condensers on the side by which the heat exchange fluid will be in the gaseous condition when the evaporator-condenser in question is in danger of the formation of frost. The central automaton  22  is connected to each pressure detector and comprises an estimator of the frost situation which executes the computation of a frost situation by computing a function depending on the flow rate of air and on the representative value of the pressure of the heat exchange fluid. The output values produced by the frost situation estimator, preferably “0” if there is no risk of frost and “1” if there is a frost situation, are registered in a table of values of frost and the upward value is transmitted as a controlled signal destined for the thermodynamic machine to reverse the thermodynamic machine operationally, as was described above. 
   It will be noted from what precedes, that the thermodynamic machine for treating air exchanged with the closed volume of agricultural products as a dryer, can work according to several modes of operation, and particularly:
         in a drying mode in which the air from the upper portion of the closed volume is brought principally through the door  6  to the evaporator-condenser  7  and is extracted from the treatment machine through the door  12  such that the air will be dried by extraction of the water vapor contained in the air removed from the closed volume  20  by cooling;   in a heating mode in which the air removed from the closed volume is heated by the evaporator-condenser  10 - 11  such that the temperature of the air blown into the closed volume  20  will be reheated;   in a cooling mode or air conditioning.       

   These three modes of operation will be better understood from the help of the description which follows. 
   Initially, it should be noted that the thermodynamic machine for treatment disposed in the compartments of the sealed cabinet  1  of  FIG. 1 , comprises in addition to the parts already described:
         an electric motor to drive a fan of evaporator-condenser  7 ;   an electric motor to drive a fan of evaporator-condenser  11 ;   an electric motor or a compressor (not shown) which permits causing the exchange fluid to circulate in the passages which connect the batteries  8  associated with the evaporator-condenser  7  and  10  associated with the evaporator-condenser  11 ;   a plurality of electromagnetic relays to control various valves which are shown in the circuit of  FIG. 4 .       

   The electrical supplies are provided or controlled by suitable output terminals of the assembly  28  of control modules of the automaton  22  according to the execution of the program executed by the processor  27 . 
   In  FIG. 3 , there is shown a diagram of the thermodynamic condition of the mass of air treated in the thermodynamic machine according to the process of the invention. 
   The axes  37  and  38  represent the measurement respectively of the temperature of the air and of the mass of water contained in the air per unit volume. The two curves  30  and  31  represent the thermodynamic conditions at constant quantity of moisture for two different values, and particularly the curve  30  which corresponds to the saturation point. The quantity of air contained in the air in the receptacle  20  is for example 18 grams per kilogram of air at 35° C. at the beginning point Dep of the treatment cycle. During step  32 , an evaporation of the mass of water in the air is carried out at a given power. 
   Then, the air undergoes cooling during step  33  by giving up a quantity of water which can reach several grams of water per kilogram of air. The mass of liquid water produced during cooling  33  is determined by the difference of height of the diagram between the straight horizontal lines  32  and  34 . 
   Then, there is carried out a step of condensation of the cooling fluid by passage of the mass of air over the condenser which works at predetermined constant power, then, by treating a constant mass of water, there is carried out a reheating  35  of the mass of air on the warm battery of the evaporator. Finally, the treated and hence dry air flow is cooled by reloading itself with water in contact with the mass of agricultural products P in the receptacle  20  to complete the cycle. 
   The automaton carries out a detection of the quantity of weight of water contained in the air such that the height of the cycle  32 – 36  tends to reduce in height, as is shown by the broken lines and the two arrows in the drawing of  FIG. 3 , up to the limit toward a limit mass of water Qtheo from which treatment can be stopped. 
   There is also shown a zone of the presence of frost ZG about the frost temperature as 0° C. When the thermodynamic machine reaches such a zone defined by a temperature gradient on opposite sides of the vertical straight line at 0° C., a process of defrosting is started which will be described later. 
   In  FIG. 4 , there is shown the fluid circuit passing through the cold batteries  6  of the evaporator-condensor  7  and hot batteries  10  of the evaporator-condensor  11  of the machine of  FIG. 1 . As shown, the fluid circuit comprises:
         non-return flap valves  45 ,  46 ;   electromechanical valves  52 ,  53  which determine a single direction of circulation (graphically shown in the direction of the point of their drawing) and which are controlled electrically by suitable output modules of the central automaton ( 22 ;  FIG. 2 );   expanders  47  and  55 ;   a reversing valve  58 ;   a compressor  55  connected to an input  60  of the reversing  58  and whose operative condition is electrically controlled by a suitable output module of the central automaton ( 22 ;  FIG. 2 ).       

   According to the operation in heating or defrosting mode or in dehumidification mode or in air conditioning mode, the direction of circulation of the fluid changes as will be explained. 
   The evaporator-condenser  40  comprises a first passage  48  connected in both directions of circulation by a passage  44  comprising a non-return flap valve  45  intermediate the inlet passage  42  of the evaporator-condenser  41 . A passage  43  comprises a non-return flap valve  46  and an expander  47  such that the fluid can circulate from the evaporator-condenser  41  toward the evaporator-condenser  40 . 
   The evaporator-condenser  40  comprises a second access passage  49  which is connected by a passage  51  and an electromechanical valve  52  connected to a first inlet passage  60  of a “three-way” valve  58 . 
   A second inlet passage  59  of the “three-way” valve  58  is connected to the access passage  61  of the evaporator-condenser  41 . 
   Finally, the second access passage  49  of the evaporator-condenser  41  is also connected by a passage  50  by means of electromagnetic valve  11  to an input passage  50  of the “three-way” valve  58 . The outlet  56  of the “three-way” valve  58  is itself connected to the passage  49  of the evaporator-condenser  40 . It will be noted that between the second access passages respectively  49  of the evaporator-condenser  40  and  61  of the evaporator-condenser  41 , there is provided a reversing valve  56 - 59  with the help of the “three-way” valve  58 . 
   Thanks to the reversing valve  58 , the fluid circuit operates according to two modes, a heating mode and a cooling or air conditioning mode. In this way, as will be explained later, the evaporator and condenser exchange their functions. 
   In the heating mode, the fluid circulates principally through the passage  43  of the first passage  48 , passes through non-return valve  46  and an expander  47  and arrives at the evaporator-condenser  40  which thus works as an evaporator by the passage  48 . Then, the fluid being evaporated through the evaporator  40 , returns through the passage  49  and  51 , passes through the electromagnetic valve  52 , enters the “three-way” valve  58  through the access passage  60 , returns through the second passage  59  to arrive by means of the passage  61  at the evaporator-condenser  41  which operates in this case as a condenser. The frigorific fluid condenses in the gaseous state through the passage  61  to pass to the inlet  60  of the “three-way” valve  58  by means of the passage  50 . 
   The frigorific fluid again leaves the three-way valve  58  by passage  56  and enters the evaporator-condenser  40  which thus operates as a condenser by means of the passage  49 . It passes through the evaporator-condenser  40  and condenses to complete the cycle and to arrive at the passage  48 . 
   The “three-way” valve  58  comprises electrical control means to operate either with its first inlet passage  60  open or with its second inlet passage  59  open. The control signals are produced according to the program executed by the processor  27  by means of the assembly of control modules  28  of the programmable automaton  22  of the device shown in  FIG. 2 . 
   In one embodiment, the evaporator  40  and the condenser  41  work at constant power, all or nothing. It follows that the fan motors associated therewith operate when they are supplied, or do not operate when, to execute a regulation of the thermodynamic cycle for treatment of the air, the program executed by the programmable automaton decides as a function of predetermined criteria of operation and as a function of predetermined criteria of electrical consumption, to operate or stop these latter. 
   In the following table in two parts, there is shown the control condition of each of the principal members of the device of the invention: 
   
     
       
             
             
             
             
             
             
             
             
             
           
         
             
                 
             
             
               mode 
               Condenser 
               evaporator 
               A 
               B 
               C 
               D 
               E 
               VI 
             
             
                 
             
           
           
             
               heating 
               M 
               M 
               F 
               O 
               F 
               O 
               F 
               not 
             
             
               (PaC) 
                 
                 
                 
                 
                 
                 
                 
               supplied 
             
             
               dehumidifi- 
               M 
               A 
               F 
               F 
               O 
               F 
               O 
               not 
             
             
               cation 
                 
                 
                 
                 
                 
                 
                 
               supplied 
             
             
               air condi- 
               M 
               M 
               F 
               0 
               F 
               O 
               F 
               supplied 
             
             
               tioning 
             
             
               Defrosting 
               M 
               M 
               F 
               0 
               F 
               F 
               F 
               supplied 
             
             
                 
             
           
        
       
     
   
   The codes in the columns of the table indicate respectively:
     “M” the condenser and/or the evaporator are operated   “A” the condenser and/or the evaporator are stopped;   “O” the register A to E is open;   “F” the register A to E is closed;   “supplied” the reversing valve  58  is supplied;   “not supplied” the reversing valve  58  is not supplied.   

   In the first column of the table, there is indicated the four modes of operation which define the four lines of the table, namely the mode of operation when heating for the first line, the mode of operation when dehumidifying for the second line, the mode of operation when air conditioning for the third line. The table has been broken into two parts with repetition of the mode column, for better understanding. 
   It will be noted that, in another embodiment, the registers A to E are provided with means permitting controlling proportionally the degree of opening of the register such that the control automaton  22  controls a plurality of conditions of opening of at least one of the registers A to E between the open condition “0” and the closed condition “F”. 
   It will be noted that the register A ( 13  in  FIG. 1 ) is noted in the table always closed “F”. In reality, in an embodiment of the invention, as a function of the detection of the instantaneous value of the external temperature Text, with ambient air in which air has been removed at least from the closed volume  20 , there is carried out a proportional opening of the register A such that constant pressure is maintained in the high pressure circuits of the cabinet  1  ( FIG. 1 ). 
   In one embodiment, there is carried out the measurement of the temperature of the external air Text and of the temperature Tevaporator in the cold battery of the evaporator  11 , the register E ( 16  in  FIG. 1 ) is controlled by proportional opening at the difference (Text−Tevaporator) such that the flow rate of the air through the battery  10  can be reduced. 
   The proportional controls of the registers A ( 13 ,  FIG. 1 ) and E ( 16 ,  FIG. 1 ) by the programmable automaton  21  ( FIG. 2 ) permit causing the compressor of the fluid circuit to operate under optimum conditions no matter what the condition of the air established both outside (atmospheric) as inside the closed volume  20  in its upper portion A. 
   In the process of the invention, as a function of the measurements of the quantity of water in the air obtained by the help of detectors Q 1  to Q 3  and as a function of a predetermined theoretical quantity Qtheo recorded in the programmable automaton, the treatment by drying is carried out with the help of the following tests: if Q 1  is greater than Q 2  then take the air to be treated principally into the closed volume  20  (portion A); if Q 2  is greater than Q 1  then take the air to be treated principally into the exterior of the closed volume  20 ; if Q 3  is greater than Qtheo then reduce the treatment power. 
   In one embodiment, the reduction of the treatment power is carried out by stopping the operation of fans  7  or  11 . In one embodiment, the reduction of the treatment power is carried out by stopping the operation of the compressor, by stopping the operation of one compressor if several compressors are disposed in a series in the fluid circuit of the thermodynamic treatment machine, or by stopping the operation of at least one compressor stage if the compressor used has several stages. 
   In one embodiment, the registers E and D are supplied principally with recycled air, which is to say with air removed from the closed volume  20  or at least from its aerial portion A. The register B is preferably but not necessarily a register supplied only with external air. In one embodiment, each register A, B, D and E, or certain ones of them, is connected by an air passage having a predetermined diameter to the small airway A of the closed volume  20  such that there is provided totally or partly a mixture of the air undergoing treatment in one of the compartments  2 – 5  of the cabinet  1  with the air to be treated. 
   In one embodiment, the sealed cabinet  1  comprises air passageways on its air access doors  6  and  12  both toward at least two closed volumes to be treated or toward a closed volume to be treated and another volume to be heated by blowing hot air. In this way, the device of the invention permits better adapting itself to the economic constraints of cost of treatment because, for example in the operational mode of the device in dehumidification, applied to a fodder dryer, for example, it is possible to apply heating to another space such as a stable or another locality to which a warm air output from the device is connectable. 
   Operational modes of the thermodynamic machine of  FIG. 1  will now be described. 
   In the dehumidifier mode, a treated airflow passes the registers  12  and  16  to the door  6 . 
   In reversible heat pump mode, the reheating of the air or the re-cooling of the air can be controlled as a function of the needs for drying or preservation. The airflows circulate from the register  14  to the door  6  and from the register  15  to the register  12 . 
   The registers  13  to  16  of the sealed cabinet  1  permit with the help of diaphragms with flaps to adjust the volume of air introduced into the different casings  2 ,  3 ,  4  and  5 . Each register is actuated by an actuator (not shown) controllable from the central automaton (not shown in  FIG. 1 ). 
   In what follows, there will be described various modes of operation of the components of the device of  FIG. 1 . 
   The cabinet  1  of the thermodynamic treatment center can be installed permanently adjacent treatment volumes, or else mounted in a transportable chassis, trailer which can be drawn by a tractor. In this case, the passages  23  and  24  (see  FIG. 2 ) can either be carried or left permanently on the drying volume. 
   The compartment  2  is a principal power-driven fan casing which draws in the treated air. The compartment  3  is a distribution casing for air to be treated. The compartment  4  is an intermediate casing. The compartment  5  is a power-driven fan casing for exhaust which carries out the evacuation of undesirable surplus energy over the refrigeration energy in the case of needed heating or of the heat energy in the case cooling is needed. An aerial loop carries out drying of the treated air. 
   The power-driven fan  7  is of the centrifugal type. The power of its drive motor is suitable for the needs of the air circuit in question for blowing the treated air. 
   The evaporator-condenser  8  is used as a condenser in the heat pump operating mode or as a dehumidifier. The evaporator-condenser  8  is used as an evaporator in the cooling mode or in the defrosting mode by reversal of hot gas. 
   The inversion register  9  is open only in the dehumidifier mode and is closed in all the other operations. Its drive is preferably carried out with the help of an actuator working all or nothing (either open or closed) under the control of the central automaton  22 . 
   The evaporator-condenser  10  is used as an evaporator in the heat pump operating mode or in the dehumidifier mode. The evaporator-condenser  10  is used as a condenser in the cooling mode or in the defrosting mode. 
   The power-driven fan  11  is of the centrifugal type. Operating in discharge, it evacuates the surplus energy: the power-driven fan operates in a reversible heat pump mode. It is stopped in the dehumidifier mode or in the deicing mode. 
   The register  13  operates to maintain high pressure. It is used in the heat pump mode or in the dehumidifier mode when the external temperature is low. This register permits deriving a portion of the air supplying the condenser  8  and permits maintaining an acceptable condensation pressure. The opening or closing of the register  13  is thus controlled by a power-driven actuator proportionally as a function of the proportional control produced by the central automaton  22 . 
   The register  14  permits carrying out a reversal of the airflow in the dehumidifier mode. This register  14  remains open in all the other modes of operation. This register coacts with a power-driven actuator proportionally as a function of a proportional control produced by the central automaton  22 . It moreover permits maintaining in the dehumidifier mode a maximum dehumidification power no matter what the weather conditions and no matter what the relative humidity of the treated air. This maintenance is carried out by derivation of a portion of the air passing through the evaporator. The inlet airflow is thus regulated proportionally to the outlet air temperature of the cold battery so as to achieve maximum condensation. 
   The register  15  permits carrying out a reversal of the airflows in the dehumidifier mode. This register  14  remains open in all other operating modes. This register  14  coacts with a power-driven actuator in all or nothing manner, under the action of control arranged by the central automaton  22 . 
   The register  15  permits carrying out a reversal of the airflows in the dehumidification mode. This register  15  remains open in the dehumidifier mode and closed in all the other modes of operation. This register  15  coacts with a power-driven actuator in all or nothing fashion, under the influence of a control arranged by the central automaton  22 . This register moreover permits holding the evaporation pressure lower than the critical evaporation pressure when the evaporator is traversed by air that is too hot. To this end, the actuator can be modified to work in a proportional mode, such that the register  16  derives a portion of this air so as to bring the evaporation pressure to a suitable value. 
   The principal modes of operation have been set forth from the point of view of all or nothing conditions of the parameters of operation or of control in the preceding table. 
   The different modes of operation are determined from, on the one hand, the needs of the client according to whether he prefers drying or preservation of the agricultural product and on the other hand of the weather conditions. 
   If the user desires preservation of his product, he selects, with the help of an input member for data internal to the central automaton  22 , such as a tactile screen or a keyboard, a mode of incooling. The control of the operation is automatically managed with the help of the program, suitably initiated, which the central automaton  22  executes when the execution has been started. In all the other cases, the operation is automatic. The program of the central automaton  22  selects the best type of operation as a function of the quality of the external air and determines the value of the different parameters of operation to be used. Thus, by detecting the humidity of the air, the central automaton  22  predetermines an operation in the dehumidifier mode; but with dry air, the central automaton  22  determines operation in a heat pump mode and if there is the detection of frost on the evaporator, the central automaton  22  determines operation in a defrosting mode. 
   There will now be described the air circuits as a function of the different types of operation. In the drawing function, the operation is identical to an air/air heat pump. The air taken in from the exterior or in the closed volume in the case of a dryer, enters by the register  15 , the register  9  being closed. It passes through the cold battery  10  which thus works as an evaporator. The inlet air cools and loses its energy. It is drawn through by the ventilator  11  and is discharged to the exterior by means of the discharge mouth  12 . The cooling circuit ensures the transfer of the energy thus recovered. 
   In one embodiment, the energy thus available is used either in the form of heat for another thermodynamic treatment process, like heating, or else recycled by a suitable machine. 
   The treated air is returned to the hot battery  8  which thus works as a condenser. The dry air from the exterior or in the dryer, enters at the same time by means of the register  14 . It passes through the hot battery  8 , is reheated and takes up energy. It expands and could thus absorb a maximum of water molecules by passing through the material to be dried. It is drawn through by the power driven fan  7  and is blown into the agricultural product to be treated by means of the outlet mouth or door  6 . 
   There will now be described the operation in the defrosting mode. The central automaton  22  receives a signal of the detection of the presence of frost on the evaporator. The program executed on the automaton  22  triggers, after a delay period which can be equal to zero, the reversal of the three-way valve and the stopping of the power-driven fan  11 . The hot battery  8  becomes a cold battery which thus works as an evaporator and the cold battery becomes a hot battery which thus works as a condenser. 
   The dry air taken from the exterior or from the dryer, enters by means of the register  14 . It passes through the cold battery  8  and gives up all its energy. It is drawn through by the power-driven fan  7  before being discharged by the mouth  6 . The cooling circuit transfers all this energy to the batter  10  which is not supplied with air and which as a result heats up very rapidly. The frost melts and the recovered water is discharged to the outside. 
   As soon as the central automaton  22  detects that there is no more frost, it stops the cooling circuit and starts the power-driven fan  11  so as to dry the battery  10 . After the lapse of a predetermined drying period, the program executed by the central automaton  22  reverses again the three-way valve and restarts the machine in the reheating mode as a heat pump as defined above. 
   There will now be described the operation in the mode of dehumidifying moist air. 
   The power-driven fan  11  is stopped. The humid air taken from the exterior or from the dryer, enters by means of the register  16  and the mouth  12 . It passes through the cold battery  10 , called in this an evaporator. It cools and reaches a so-called dew point temperature. It condenses on the cold battery, discharges the air which it carries and loses all its energy. The cooling circuit transfers all of this recovered energy to the hot battery  8  (sensible energy and latent energy). The air without its water which leaves through the battery  10 , passes through the register  9 , passes through the hot battery  8  and is reheated to a temperature above the initial inlet temperature. The thermodynamic machine receives the restitution of the latent energy contained in the air to be dehumidified and the energy consumed by the compressor to cause the cooling liquid to pass from a low pressure level to a high pressure level. The air expands so as to be able to absorb more water and is blown toward the material to be dried wit the help of the power-driven fan  7  and the blowing mouth  6 . No matter what the initial humidity of the air to be treated, the evaporating power of the blown air remains of the same quality. 
   There will now be described the operation in the cooling or air conditioning mode. 
   The reversing valve is powered and the cycle is reversed. It is necessary to evacuate the heat (excess heat energy). The air taken from the exterior or the dryer, enters the register  14  (the register  9  is closed). It passes through the cold battery  8 , in this case the evaporator. It is cooled and loses its energy. It is sucked in by the power-driven fan  7 , and is blown into the product to be cooled by means of the blower mouth  6 . The cooling circuit ensures the transfer of energy thus recovered, to the hot battery  10  called in this case a condenser. The air taken from the exterior or from the dryer, enters at the same time by means of the registers  15 . It passes through the hot battery  10 , is reheated and takes on energy. It is sucked in by the power-driven fan  11  and is discharged; and in the same way rejects the excess heat energy to the exterior by means of the mouth  12 . 
   There will now be described a means to optimize the cooling operation of the machine. The means to optimize the cooling operation of the machine comprises a module for maintaining optimum condensation pressure. This mode of operation is triggered particularly when the external temperature is low. It can be controlled by the central automaton  22  with the help of its computer-operated program. 
   In the case of operation at low temperature, the register  13  opens to a degree of opening which is a function of the decrease of the condensation pressure. A portion of the air sucked in by the power-driven fan  7  enters through the register  13 . The hot battery  8  is less supplied with cold air, the air entering through the register  14 . As temperature rises, the power of the compressor remains constant and at the same time the condensation pressure returns to a correct value. 
   The means to optimize the cooling function of the machine comprises a module to limit the upper values of the evaporation pressure (high external temperature). 
   In the case of operation at a high external temperature, in operation as a heat pump re-heater, the program executed by the central automaton  22  controls the maintenance of a correct evaporation pressure by means of the register  16 . In the case of operation at high external temperature, the register  16  opens proportionally as a function of the increase of evaporation pressure. A portion of the air drawn in by the power-driven fan  11  enters through the register  16 ; the cold battery  10  is less supplied with hot air (air entering through the register  15 ). Its temperature again falls, the power of the compressor being constant, and at the same time the evaporation pressure returns to a correct volume. 
   The means to optimize the cooling operation of the machine comprises an operating module for maintaining the dehumidifying power. 
   In the case of operation in the dehumidifying mode, when the external temperature is high, the quantity of water contained in the air can be too great despite a relatively low relative humidity. For example, for a temperature of 32° C. and a humidity of 40%, the weight contained in a kilogram of dry air is 12 g. This quantity is too high to ensure correct drying. In this case, the cooling power to be used to cool the air to its dew point (16.5° C.) and to permit substantial condensation of the humidity contained in the air is very high. So as to overcome this problem, by means of the register  14 , the program executed on the central automaton  22  controls the inlet of a portion of the air sucked in by the power-driven pump  7 . The quantity of air passing through the cold battery  10  decreases, its temperature falls. The power of the compressor being held constant by the central automaton  22 , the temperature at the outlet of the battery falls and the dehumidifying power remains optimum. The centralized control of the machine permanently controls, in this case, the temperature of the air at the outlet of the evaporator and, if need be, manages proportionally the opening of the derivation register  14 . 
   The process of the invention comprises a preliminary step to calculate the operating regime of the treatment machine adapted to a treatment objective. The operating regime is defined by an assembly of predetermined values of operating parameters which depend on the material constituting the treatment device of the invention. In particular, certain operating parameters describe the geometric dimensions of the machine such as for example the length, the cross-sections and the pressure drops of the passages or of the treatment compartments of the thermodynamic treatment machine. These parameters are fixed and are selected during production or installation of the machine. Other operating parameters are determined once for all time at least during an experimental period, such as the installed electrical power, or the losses from the thermal insulation and depend on the choice of construction during installation of the treatment device. Finally, other parameters can be modified or controlled during the execution of a treatment or a series of treatments as has been described above. 
   The treatment objective depends on the nature of the treatment and on the products undergoing treatment. It is determined in a manner to optimize the treatment result by respecting the technical constraints, particularly safeguarding the treatment device and the products undergoing treatment, and economic constraints taking account of the cost of energy consumed (particularly the cost of electrical energy supply) but also amortization of the installations and of the treatment device. 
   The treatment results, and particularly the treatment objectives, are measured by parameters relating to the products to be treated. For example, for products such as fodder and for a drying treatment, the user can fix the quantity of dry materials which will be compared to a theoretical threshold quantity at the end of treatment Qtheo which has been expressed above. The user can also fix a drying time and take account in this connection of climatic constraints. 
   It will be noted that among the operating parameters, certain of them are controllable such as the operating condition of the actuable elements of the treatment device, as has been described. The values of these parameters are thus modified while carrying out treatment. 
   The treatment device is connected to a receptacle for products to be treated. Several receptacles can be mounted in series or in a star arrangement on the same device. Moreover, these receptacles are not necessarily completely sealed, whether it is desirable to maintain a certain quantity of humidity or whether perfect sealing would be too costly to obtain. 
   As a result, the communication of the treatment air with a receptacle can be arranged such that the air flow circulates through the mass of products to be treated, or not. It is a matter of circumstances which depend on the products and their receptacle. 
   It has also been described that the treatment process could carry out a humidification of the treatment airflow. In particular, such a treatment could also be used by saturating the airflow blown through the receptacle with steam from a treatment product which can be water or an aqueous solution of products of a chemical or biological treatment. In this case, a liquid water injection member or an aqueous solution injection member is provided which works in a warm battery of an evaporator-condenser of the treatment device, or by atomization in a power-driven fan of the treatment device. 
   In particular, the treatments of heating and cooling, dehumidification and humidification of the treatment air carried out by the treatment device can be such that the air is either the only treatment element of the products to be dried or that it is the vector of another treatment product or effect such as cold or heat. 
   It will also be noted that the treatment process of the invention permits regulating or controlling the flow rate of treatment air by controlling the power of the motor-driven fans or the pressure drop particularly through the registers A to E described above. Such a regulation can constitute by itself a particular treatment of the products to be treated in receptacles such as a mechanical agitation of portions of these products or to carry away dust associated with these products. 
   Among the treatments envisageable with the help of the device of the invention, it will be noted that the dehumidification treatments of the treatment air must be controlled because the dried treatment air thus acts like a sponge which will extract moisture from products to be treated in the receptacle  20 . As a result, the central automaton  22  of the device of the invention comprises a module adapted to add external air which will be more humid, to avoid over-drying the products to be treated. 
   The device of the invention, more particularly the thermodynamic machine, comprises a reversing valve which permits principally reversing the operation of the thermodynamic cycle. It thus permits changing the functions of the condenser or of the evaporator among the two evaporator-condensers of the machine. This reversing valve has been shown in  FIG. 4  with as a “three-way” valve and several expanders or non-return valves to ensure its operation. The same result could be achieved with a “four-way” valve with a slide with two positions actuated under the control of the central automaton  22 . 
   The central automaton  22  also comprises a control module to regulate the assembly of predetermined values of the operating parameters. Such a control module can be accessible to the user to input initial values of the operating parameters or reference values or alarm values, as has been described above. 
   The central automaton  22  also comprises a module for regulation of the treatment program by means of the control module, in which the reference and alarm values are compared to detected or estimated values of the operating parameters at each instant so as to achieve the objects and results of treatment as has been described above. 
   It will be understood that the modules of the central automaton  22  are essentially comprised by macro-programmable functions and electronic power circuits to control the operation of the electrical motors and the actuators described above. 
   In one embodiment, the treatment device of the invention also comprises a module for exploiting the energy A 1  recovered during treatment of the treatment air by the thermodynamic machine. Such a module could comprise an independent circuit of a heat exchange fluid which recovers the cooling energy of the treatment air and which circulates toward a heating radiator or toward a means for recycling energy.