FIELD OF THE INVENTION

The present invention concerns an apparatus and method to make water drinkable, in particular an apparatus and a method to purify salt water, waste water, or other type of polluted water, also coming from sewage drains, or in any case not drinkable, eliminating pollutants, dirt, or otherwise, making it drinkable.

The present invention concerns, in particular but not restricted to, an apparatus to make water drinkable in which at least one primary heat generator is provided, intended as a source of traditional energy, such as a heat pump, a boiler or suchlike, therefore able to deliver a fixed energy, and at least one secondary heat generator, intended as a discontinuous source of energy, such as for example wind or solar sources, consisting, for example, of photovoltaic panels, solar collectors, electricity generators or suchlike.

BACKGROUND OF THE INVENTION

Plants and apparatuses for purifying and desalinating water to obtain drinking water are known, for example, purification apparatuses are known which can be classified into the following types:

- ion exchange, which however must be frequently cleaned and are not efficient in the case of high salt concentrations,

- electrodialysis, which however are very expensive as they require a high quantity of energy,

- reverse osmosis, which however have high costs due to both the cost of the membranes and the high cost of disposing of them as special waste, as well as the cost of electricity required for running them.

From document WO-A-2013/107469, for example, a desalination apparatus with distillation is known, to purify salt water by eliminating the solids dissolved therein and making it drinkable. This apparatus comprises a "hot" zone, in which the water contained in a casing is evaporated and water vapor is generated, and a "cold" zone in which the condensation of the water vapor takes place.

This apparatus therefore substantially exploits a saturated air humidification in a hot zone, condenses the humidity contained in the air in a cold zone and obtains a water free from salts or other elements which can be incompatible with the requirements of suitability for human consumption.

This apparatus, however, can be complex and complicated, limited in production due to the limits of the temperatures imposed on the primary heat generator and the air flows that can be exerted. Moreover, this apparatus proves not easy to manage, precisely because of its complexity.

A further limitation of this apparatus and of known apparatuses in general, is that it is impossible to operate efficiently with multiple energy sources or generators, synergic with each other and by definition discontinuous, such as for example solar, wind or other sources of energy, which are able to deliver electrical and/or thermal energies, generally available in a civilian district, in combination with traditional energy sources, for example heat pumps, gas boilers or suchlike.

Known apparatuses and plants to make water drinkable are therefore substantially incompatible if it is desired to use a traditional heat source, such as a heat pump, a boiler or suchlike, combined with a discontinuous type of heat source, such as for example a solar or wind energy source or suchlike, for example photovoltaic panels, solar collectors or suchlike.

Another known apparatus to make water drinkable, which has the above limits and disadvantages, is described in document KR-2011-A0080215.

Other limitations and disadvantages of conventional solutions and technologies will be clear to a person of skill after reading the remaining part of the present description with reference to the drawings and the description of the embodiments that follow, although it is clear that the description of the state of the art connected to the present description must not be considered an admission that what is described here is already known from the state of the prior art.

There is therefore a need to perfect an apparatus and method to make water drinkable which can overcome at least one of the disadvantages of the prior art, obtaining a greater efficiency of potabilization compared with the solutions of the prior art and which can be used both in the domestic field and on an industrial level.

One purpose of the present invention is therefore to provide an apparatus to make water drinkable which can operate with at least two sources of energy, in a synergic manner and so as to obtain an efficient heat generation and an optimum temperature for heating the water to be treated in order to obtain drinking water.

Another purpose of the present invention is to provide an apparatus to make water drinkable which, advantageously, can operate with one or more generators or sources of energy, synergic with one another and also discontinuous or variable, such as for example solar, wind or other energy sources, able to deliver thermal and/or electric energies, generally available in a civilian district, combined with traditional generators or sources of energy, such as heat pumps, boilers or suchlike.

Another purpose of the present invention is to provide an apparatus to make water drinkable which is therefore able to efficiently combine sources or generators of fixed energy, such as at least a primary heat generator of the traditional type, with at least one secondary heat generator with discontinuous or variable energy, such as a so-called renewable energy source, so as to effectively absorb and exploit both the heat generated by the traditional fixed energy source and also the one generated by the variable energy source.

A further purpose of the present invention, moreover, is to provide an apparatus to make water drinkable which allows a significant increase of the temperature of the humid air obtained in the "hot" zone, with consequent increase in steam contained in the same volume of air, greater heat energy absorbed, therefore, in short, greater and more efficient production of drinkable water.

A further purpose of the invention is to perfect an efficient method to make water drinkable.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, an apparatus to make water drinkable according to the present invention comprises at least a tank of water to be made drinkable, heated by means of a fluid that flows in at least a heating circuit, and at least a condensation unit, configured to receive humid air exiting from the tank and to produce drinkable water.

According to a characteristic aspect of the invention, the apparatus comprises at least a mixer device associated with the heating circuit of the water to be made drinkable, by means of first delivery and return pipes of the heating fluid to and from the heatmg circuit, with at least a primary heat generator, by means of second delivery and return pipes of the heating fluid to and from the primary heat generator, and at least a secondary heat generator, comprising third delivery and return pipes of the heating fluid, the mixer device is configured to transfer and regulate the heat made available by the primary and secondary heat generators, keeping the temperature of the fluid in the third pipes associated with the secondary heat generator, or in the heating circuit, at an optimal value, thanks to the mixing of the heating fluid performed inside the mixer device; the heating fluid is made to circulate by means of the first, second and third pipes through the mixer device, the heating circuit, the at least one primary heat generator and the at least one secondary heat generator.

Advantageously, in this way, it is possible to obtain an optimal temperature of the heating fluid that flows in the heating circuit of the water to be treated and, at the same time, to optimize the energy consumption of the apparatus.

According to some embodiments, the primary heat generator is a source of fixed heat, for example a boiler or a heat pump, while the secondary heat generator is a source of variable heat, for example solar collectors, and the mixer allows to regulate the flow of the secondary heat generator as a function of the temperature available by this, in order to reduce the consumption of the primary heat generator in the case of a boiler, or to improve the production efficiency of the water in the case of a heat pump.

The mixer device can comprise at least a container with which the first, second and third delivery and return pipes of the fluid are associated to and from the primary and secondary heat generators and to and from the heating circuit.

The first, second and third pipes can be associated with the container from an upper part to a lower part thereof on the basis of the temperature of the fluid in the first, second and third pipes: the pipes with the fluid at higher temperatures are positioned in the upper part of the container and the pipes with the fluid at lower temperatures are positioned in the lower part of the container. The secondary heat generator can be associated with at least a source of renewable energy, such a solar energy, internal combustion engines, wind energy or suchlike.

In some embodiments the primary heat generator can be a heat pump.

The heat pump can comprise a delivery pipe of the fluid to the mixer device associated with an intermediate zone of the container.

In some embodiments, the primary heat generator can be a gas boiler.

The gas boiler can comprise a delivery pipe of the fluid to the mixer device associated with the upper part of the container of the mixer device.

The container can be a cylindrical shape and optionally can have a lower part shaped like a truncated cone.

The diameter of the container can be equal to at least half the height of the container.

The diameter of the container can be sized according to the following formula:

ϋ ³ =Ν/2*Ρρ/π

where N indicates the latency time of the primary heat generator and Pp indicates the flow rate of the heating fluid in the primary heat generator.

Another object of the invention is a method to make water contained in a tank drinkable, which provides to: heat the water to be treated in the tank by means of a heating fluid that flows in at least a heating circuit associated with at least a primary heat generator and at least a secondary heat generator, where the heating fluid flows; to introduce the heating fluid into at least a mixer device associated by means of first pipes with the heating circuit, by means of second pipes with the primary heat generator and by means of third pipes with the secondary heat generator, so as to keep the temperature thereof at an optimal value in the first pipes of the secondary heat generator; to produce humid air in the tank and transfer it to a condensation unit.

According to another aspect of the invention, the regulation of the flow rate of heating fluid to the heating circuit is carried out by regulating the flow rate of the fluid to the secondary heat generator.

According to other embodiments, the method provides to regulate the flow rate of the secondary heat generator as a function of the temperature of the fluid made available by it, in order to reduce the consumption of the primary heat generator or to increase the temperature of the fluid in the heating circuit.

These and other aspects, characteristics and advantages of the present disclosure will be better understood with reference to the following description, drawings and attached claims. The drawings, which are integrated and form part of the present description, show some forms of embodiment of the present invention, and together with the description, are intended to describe the principles of the disclosure.

The various aspects and characteristics described in the present description can be applied individually where possible. These individual aspects, for example aspects and characteristics described in the specification or in the attached dependent claims, can be the object of divisional applications.

It is understood that any aspect or characteristic that is discovered, during the patenting process, to be already known, shall not be claimed and shall be the object of a disclaimer.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

- fig. 1 is a schematic view of an apparatus to make water drinkable according to a first executive embodiment of the invention;

- fig. 2 is a schematic view of an apparatus to make water drinkable according to another executive embodiment of the invention;

- fig. 3 is a schematic view and in lateral elevation of a mixer device provided with a container;

- fig. 4 is a three-dimensional view of a heating circuit of the water to be treated provided with a diffuser element;

- fig. 5 is a view from below of the diffuser element in fig. 4;

- fig. 6 is a three-dimensional view from below of the diffuser element in fig. 5.

To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS We will now refer in detail to the various embodiments of the present invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants.

Before describing these embodiments, we must also clarify that the present description is not limited in its application to details of the construction and disposition of the components as described in the following description using the attached drawings. The present description can provide other embodiments and can be obtained or executed in various other ways. We must also clarify that the phraseology and terminology used here is for the purposes of description only, and cannot be considered as limitative.

An apparatus 10 or 11 to make water drinkable according to the invention, see fig. 1 or fig. 2, can be used to treat salt water, waste water, or other types of polluted water, for example also coming from sewage drains, or in any case non- drinkable, eliminating pollutants, dirt, or otherwise, making it drinkable.

As we said previously, elements common to both the executive variants of the apparatus 10 or 1 1 are indicated with the same reference numbers in figs. 1 and 2.

Considering, for example, the apparatus to make water drinkable 10 in fig. 1, the apparatus 10 provides a tank 12 for containing and/or accumulating the water A to be made drinkable, which can be hermetically sealed during use. The tank 12 substantially represents a "hot" section of the apparatus.

The water accumulated in the tank 12 can contain, for example, salt, pollutants, bacterial load or solid residues, which make it non-drinkable and not suitable for use by a user.

The tank 12 comprises a lower part 12a configured to contain the water to be made drinkable for a certain vertical portion, and an upper part 12b, configured to define a sufficiently large accumulation chamber for the humid air.

The tank 12 comprises at least one inlet pipe 13 for the water to be made drinkable, which can take water directly from the sea, or can be connected to a well 14, for example by means of an immersion pump 15, to remove water from a water table.

The inlet pipe 13 for the water to be made drinkable may not require filters during the removal, since any solid residues settle at the bottom of the tank 12 and can be removed during the programmed emptying operations.

The tank 12 can also comprise a water outlet pipe 17 toward a drainage or dilution tank, for example to reduce the concentration of salts from the water before discharging it into the sea or into a water table, for example to perform periodic maintenance operations.

Valves can be provided to respectively open/close the water inlet pipe 13 and/or outlet pipe 17 from the tank 12.

The tank 12 also comprises insufflation means for blowing in hot air, configured to be saturated with humidity from the water present in the tank 12. The tank 12 comprises a hot air inlet 21, which can be associated with the insufflation means, positioned in correspondence with the lower part 12a of the tank 12.

The hot air inlet 21 can be, for example, an aperture or a passage pipe for hot air.

The hot air inlet 21 can be positioned, for example, under a minimum level of the water A to be made drinkable, during the normal functioning of the apparatus 10, in the tank 12.

The hot air inlet 21 can for example be positioned at about half the vertical extension of the lower part 12a.

According to some embodiments, the hot air inlet 21 is positioned in a lateral wall of the tank 12.

The tank 12 also comprises an exit pipe 19 for the humid air, which can be positioned in the upper part 12b of the tank 12 to allow the exit of the humid air.

The apparatus 10 also comprises a condensation unit 16, disposed in fluid cooperation with the tank 12, for example by means of the humid air outlet pipe 19. The condensation unit 16 represents a "cold" section of the apparatus.

The condensation unit 16 comprises a heat exchange and recovery section 18 and a condensation section 20, configured to progressively cool and condense the humidity of the air coming from the tank 12. According to one solution, the heat exchange and recovery section 18 and the condensation section 20 can be air-air heat exchangers, in which the humid air coming from the tank 12 can flow into separate pipes, with the ambient air taken from outside the condensation unit 16.

The humid air coming from the tank 12 can then be made to pass through the heat exchange and recovery section 18, partially cooling and giving up heat to the air flowing on an adjacent heat exchange pipe.

Subsequently, the partially cooled humid air passes through the condensation section 20 in which it gives up heat to the air taken from the outside, giving off condensation. The condensed water vapor precipitates toward the bottom of the condensation section 20.

In the apparatus it is also possible to provide a tank 22 to collect the condensation, which collects the purified water B exiting from at least one pipe 23 located downstream of the condensation section 20.

Furthermore, at the outlet of the condensation unit 16, an outlet pipe 24 for the heated air is provided, associated with the heat exchange and recovery section 18.

The heated air pipe 24 can be connected to the hot air inlet 21 to allow the flow of the heated air from the condensation unit 16 to the tank 12.

The air with reduced absolute humidity exiting from the condensation section 20 could be forcibly circulated again in the heat exchange and recovery section 18, in which it is heated again before being made to exit through the pipe 24 for the heated air.

The condensation unit 16 is configured to use the heat of the phase change (steam - water) to heat the air toward the heated air pipe 24, before introducing it into the tank 12 through the hot air inlet 21.

According to some embodiments, an air movement unit 25 is provided, disposed along the heated air pipe 24, such as a fan, or an air suction pump.

The air movement unit 25 is configured to move, for example through suction, the heated air from the heat exchange and recovery section 18, and introduce it with a desired pressure into the tank 12, through the inlet 21.

When the air movement unit 25 is stationary, the volatile substances due to the raised temperature have a way to exit the tank 12, which prevents them from being diffused in the condensation water. The heated air in the heat exchange and recovery section 18 is sent into the tank 12 below the level of the liquid head of the water A to be made drinkable, so as to spread in one or more points below the level of the liquid head, taking with it water vapor that tends to saturate the upper part of the tank.

Downstream of the heated air pipe 24, a diffuser 32 can be provided, disposed inside the tank 12 and associated with the hot air inlet 21.

The diffuser 32 is configured to convey the air uniformly over the entire surface of the water, so as to prevent nebulization and therefore transport of water with its contents in the humid air and therefore in the condensation unit 16. The diffuser 32, schematically shown in fig. 1 and fig. 2 and described in more detail below, can be interposed between two heat exchange devices 28 and 29 of a heating circuit 27 of the water A.

The upper heat exchange device 28 can be disposed in proximity to the level of the liquid head of the water A.

The lower heat exchange device 29 can be disposed in proximity to the bottom of the tank 12.

The heating circuit 27 is provided with a pipe 26 to feed or deliver the heating fluid and with a return pipe 30 for the heating fluid.

The delivery and return pipes 26 and 30 of the heating fluid are connected to a mixer device 31 comprising at least one container 33.

The heating fluid feed pipe 26 is preferably connected in an upper zone 34 of the container 33, where the heating fluid contained therein has the highest temperature.

The heating fluid return pipe 30 from the heating circuit 27 preferably reaches a lower zone 35 of the container 33, where the fluid is at its lowest temperature.

The heating fluid is circulated in the container 33 and then in the heating circuit 27 by suitable recirculation means, such as a pump 40 or suchlike.

In general, the pipes which are connected to the container 33, whether they are delivery or return pipes of the heating fluid to and from the container 33, are preferably disposed from the top downward according to the temperatures at which the fluid in the pipes finds itself. Thus, if a first pipe is connected to the container 33 at a greater height than a second pipe, it means that the temperature of the fluid in the first pipe is higher than the temperature of the fluid in the second pipe.

The mixer device 31 is in particular a passive device and is configured to transfer, substantially continuously, all the heat available to the heating fluid that passes through the heating circuit 27, since this heat is supplied in particular by at least two different energy sources or generators: a primary heat generator, for example a traditional fixed-energy generator, identified in the example of fig. 1 by a heat pump 45, and a secondary heat generator 37, see also fig. 2, for example a generator of variable or discontinuous energy, such as photovoltaic panels, solar collectors, wind sources, electricity generators or suchlike.

The mixer device 31 and the primary and secondary heat generators 37 are therefore part of the heating circuit 27.

The heating fluid circulating in the secondary heat generator 37 is sent to the container 33 of the mixer device 31 by means of a first pipe 38 and returns to the secondary heat generator 37 by means of another pipe 39.

The pipes 38 and 39 therefore define a circuit of the secondary heat generator 37 in which the heating fluid flows.

Preferably the pipe 38 for sending the fluid from the secondary heat generator 37 to the container 33 is located in the upper zone 34 of the container 33.

The fluid return pipe 39 to the secondary heat generator 37 is preferably connected to the lower zone 35 of the container 33.

The fluid is circulated between the secondary heat generator 37 and the container 33 by suitable recirculation means, for example a pump 41 or suchlike.

Also the heat pump 45 is provided with its own circuit where the heating fluid flows, which, after suitable mixing in the container 33 of the mixer device 31, will be sent to the heating circuit 27.

The fluid heated by the heat pump 45 is introduced into the container 33 through a pipe 46.

Preferably, the pipe 46 is located in proximity to an intermediate zone between the upper zone 34 and the lower zone 35 of the container 33, since, generally, the working temperatures of a heat pump are lower than those obtainable by the secondary heat generator 37, for example an array of photovoltaic panels, provided with cooling, or from solar collectors.

The fluid is then returned to the heat pump 45 through another return pipe 47. Preferably, the pipe 47 is located in proximity to the lower zone 35 of the container 33.

The heating fluid is circulated between the heat pump 45 and the container 33 of the mixer device 31 by suitable recirculation means, such as a pump 48 or suchlike.

The secondary heat generator 37, the primary heat generator, therefore in this example the heat pump 45, and the heating circuit 27 of the water A to be treated are therefore flmdically connected to the mixer device 31.

The mixer device 31 thus allows to obtain an optimum temperature of the heating liquid in the inlet pipe 26 to the heating circuit 27 and at the same time to increase the productivity of the heat pump 45.

The mixer device 31, and in particular the container 33, is sized according to the power of the primary heat generator, in this case the heat pump 45.

The flow rate of the corresponding circulation pump 48 is sized according to the nominal power of the heat pump 45, in order to obtain an optimal temperature difference, appropriate to the characteristics of the condensation exchanger of the cryogenic gas of the pump itself.

For example, for a heat pump capable of delivering a power equal to 3 thermal kW in its operating range in temperature, a temperature difference of about 5°C is optimal for its functioning, so a sizing of the circulation pump 48 is obtained for about 8 liters/minute of flow rate of heating fluid.

The volume of the mixing container 33, also shown schematically in fig. 3, must be such as to guarantee the necessary stoppage times of the heat pump 45, after restarting the gas compressor: this usually requires a margin of several minutes, which means a volume of about 4 or 5 times the flow rate per minute of the heat pump can be sufficient for the above purpose.

The container 33 could be provided with the lower zone 35 having a conical or truncated cone shape, so as to allow a uniform connection with the pipe 30, in this case, see fig. 3.

In the case of a cylindrical container 33, it can be hypothesized that the diameter D of the container is at least half the height H of the container, so as to satisfy the above volumetric requirement.

In particular, the diameter D, sized as a function of the flow rate of the main device, that is, of the primary heat generator (for example, depending on the fluid flow rate Pp of the heat pump 45), can be obtained according to the following formula:

ϋ ³ =Ν/2*Ρρ/π

where N indicates the latency time of the primary heat generator, for example of the heat pump 45.

The circulation pump 40 of the heating fluid of the water to be treated is activated when the temperature of the heating fluid in the delivery pipe 26 reaches the desired value, for example about 60°C, which is an optimum temperature for the operation of the heat pump 45 of the example above.

The heat pump 45, that is in the case shown by way of example the primary heat generator, has a flow rate set to the optimum normal working condition of the heat pump 45, while the flow rate of fluid in the heating circuit 27, pump 40, is calculated and set at a sum value depending on the energy level of the heat pump 45 and the maximum flow rate assigned to the secondary heat generator 37 in relation to the power installed. This allows, advantageously, that the temperatures under normal working conditions of the fluids at the pumps 40, 41, 48, and therefore in the return pipes, remain around designated levels, for example about 55°C, given the control of the heat absorption in the hot section of the apparatus, and therefore in the tank 12.

Substantially, therefore, according to the example given above, there is a delivery temperature of the heating fluid in the pipe 26 of the heating circuit 27 of about 60°C and a return temperature from the pipe 30 of about 55°C.

The pump 41 of the secondary heat generator 37, let us suppose by way of non-restrictive example, an array of solar panels, is activated when the temperature of the fluid in the pipe 38 exceeds the temperature of the fluid in the pipe 26: as we said, as the temperature of the fluid in the pipe 38 can be higher than the temperature of the pipe 46 of the heat pump, its inlet is on the upper zone 34 of the container 33, while the inlet of the pipe 46 is in a lower intermediate zone of the container 33.

The fluid flow rate of the pump 41 of the secondary heat generator 37 is preferably regulated so as to always obtain a temperature of the fluid in the pipe 38 higher than the temperature of the fluid in the pipe 26, thereby obtaining all the available power of the secondary heat generator 37, in particular a solar apparatus formed for example by several solar panels, while the temperature of the fluid in the delivery pipe 26 always remains at a temperature condition which guarantees efficiency of the solar apparatus, if it consists of photovoltaic panels with a cooling circuit.

By way of non-restrictive example, for an array of photovoltaic panels of 10m , from an irradiation of 400 W/m (insolation in the tropical zone with a veil of clouds), a thermal power of about 2.4 kW can be obtained which, with a flow rate of about 3.5 1/min, develops a temperature difference of about 10°C. This allows to have available, as we said above, a temperature of the heating fluid on the pipe 26 of about 60°C and a temperature of the fluid on the return pipe 30 of about 55°C, which are optimal temperatures both for the heat pump and also to keep the photovoltaic panels at an optimal temperature of efficiency. It should be noted that the performance of a normal photovoltaic apparatus decreases considerably for operating temperatures above about 70-80°C, which can be reached and easily exceeded even in temperate zones during the hours of greatest insolation.

Again according to the previous example, with standard insolation, that is, about 1000 W/m ² , a temperature of the heating fluid in the pipe 26 of about 63 °C would be obtained, therefore with a higher productivity of treated water B and a better coefficient of the performance of the heat pump 45, therefore lower specific electrical consumption.

In the case of fig. 2, a gas boiler 36 is used as the primary heat generator. The gas boiler 36 comprises corresponding delivery and return pipes 42 and 43 for the heating fluid, circulated by suitable recirculation means, for example a pump 44.

The flow rate of fluid in the heating circuit 27 is in this case sized according to the flow rate of fluid to the gas boiler 36. In normal working conditions, the temperature of the return fluid to the boiler 36 and hence in the pipe 43, can have a temperature suitable for an average power regime and intermediate flame regime of the gas boiler 36.

For example, it can be hypothesized that the gas boiler 36 modulates the flame in order to obtain the maximum operating temperature, for example 80°C, with a fluid flow rate set by the circulation pump 44. In this case, the temperature of the fluid in the return pipe 43 to the gas boiler 36 could be about 50°C, hence an intermediate flame regime and, consequently, an intermediate operating power.

The fluid delivery pipe 38 from the secondary heat generator 37 is positioned at an intermediate height of the container 33' of the mixer device 3 , given that, normally, the operating temperature of the primary heat generator, in this case the gas boiler 36, exceeds the optimal operating temperatures of the secondary heat generator 37, for example a photovoltaic panel, a solar collector or other.

Thanks to the mixer device 31 it is possible to reduce the working power of the gas boiler 36, if the power delivered by the secondary heat generator 37 is sufficient, by circulating the fluid through the circulation pump 41. The greater the power delivered by the secondary heat generator 37, therefore, the lower the flame regime with which to make the gas boiler 36 function. With a sufficient power of the secondary heat generator 37, it is possible to completely switch off the gas boiler 36. This naturally allows substantial savings in gas consumption, without discontinuity in the production process of treated water B exiting from the condensation unit 16.

The circulation pump 41 of the secondary heat generator 37 preferably functions as described above with reference to the apparatus 10 in fig. 1, and according to the same temperature values.

Both when using the heat pump 45 as the primary heat generator, and also when using the gas boiler 36, the regulation of the flow of heating fluid to the heating circuit 27 is in any case carried out, preferably, only on the flow rate of fluid of the secondary heat generator 37 with variable energy, so as to modify the temperature of the fluid of the secondary heat generator 37, and to keep the temperature of the fluid in the heating circuit 27, in particular in the pipe 26 or in the pipes 39 and 38 associated with the secondary heat generator 37, at an optimal value, thanks to the optimal mixing of the heating fluid in the mixer device 31, 31 '.

Therefore the mixer device 31 , 31 ' is, in short, connected to the heating circuit 27 by first pipes 26, 30, to the gas boiler 36 or to the heat pump 45, therefore to the primary heat generator, by means of second pipes 42, 43 or 46, 47, and to the secondary heat generator 37, by means of third pipes 38, 39, as clearly shown in fig. 1 and fig. 2. In short therefore, the application of the mixer device 31 to the apparatus 10 to make water drinkable provided with a heat pump 45 as a primary heat generator and with a secondary heat generator 37, allows to increase productivity and therefore the quantity of water treated given the same consumption. This is obtained, in particular, thanks to the energy of the liquid/steam phase change, which allows to obtain a greater quantity of water in the form of steam, at the same temperature, given the greater working efficiency of the heat pump.

The application of the mixer device 31 ' to the apparatus 1 1 to make water drinkable with a gas boiler 36, as we said, allows a considerable saving of gas. The reduction in consumption is obtained in particular thanks to the contribution of the secondary heat generator 37 which increases the temperature of the fluid in the return pipe 43 of the gas boiler 36, in this way the boiler operates at a reduced power regime, even to the point where it completely switches off.

The heating circuit 27, in the part located inside the tank 12, comprises a support structure 49 able to house the two heat exchange devices 28 and 29 and the diffuser 32.

The upper heat exchange device 28 comprises a first tubular element 50, for example wound in a spiral, and connected on one side to the inlet pipe 26 of the heating fluid and, on the other side, to a pipe 51, located for example in a central position and able to transfer the heating fluid toward a second tubular element 52, which is also wound for example in a spiral.

The heating fluid flows through the second tubular element 52, for example from the inside to the outside, and then flows into a pipe 53 that connects with a first tubular element 54 of the lower heat exchange device 29.

The heating fluid passes from the first tubular element 54 to a second tubular element 55 by means of a pipe 56, flows through it and comes out of the outlet pipe 30.

The tubular elements 50, 52, 54 and 55 of the heat exchange devices 28 and 29, in particular if made in a spiral and preferably at a regular pitch, are positioned uniformly and without interruptions inside the part of the tank where the water A to be treated is accumulated and where there is the hot air inlet 21.

The hot air inlet 21 is in fluid communication, through an entrance aperture 57, with the diffuser 32, see figs. 5 and 6. The diffuser 32 comprises a plate 58 provided with a series of holes 59, through which the air coming from the inlet 21 and hence from the entrance aperture 57 flows.

The holes 59 can be uniformly distributed over the entire surface of the plate 58.

The holes 59 can have a diameter of, for example, about 2 mm. The sizes of the holes 59 of the plate 58 of the diffuser 32 and their disposition can vary according to the consistency of the water A to be treated.

The entrance aperture 57 receives the air when it is introduced into the water A contained in the tank 12, and the diffuser 32 thus allows to distribute the air in the water A on a transverse plane substantially parallel to the plate 58, at a height corresponding to the position of the inlet 21.

The entrance aperture 57 is preferably positioned in correspondence with the periphery of the plate 58, on the surface that faces, during use, the bottom of the tank, so that the hot air, when it arrives from said aperture 57, can then flow into the water A under the plate 58.

According to some embodiments, the entrance aperture 57 is positioned in a peripheral portion 58a of the plate 58.

According to some embodiments, the entrance aperture 57 is configured to receive the flow of air from the inlet 21 in a lateral direction, for example radial in the case of a cylindrical tank 12.

The plate 58 preferably has a shape corresponding to the shape of the internal section of the tank 12 where it is located: supposing that the tank 12 has a cylindrical internal shape, the plate 58 will have a circular shape, so as to substantially occupy the entire internal section of the tank 12.

For example, according to this embodiment, the peripheral portion 58a is located in proximity to a circumferential zone of the plate 58.

The air coming from the entrance aperture 57 can therefore pass through the holes 59 of the plate 58 and pass through the plate 58, from the bottom upward, so as to be introduced into the water A to be treated.

The diffuser 32 can also be provided with a series of channels 60 to convey the air entering from the entrance aperture 57.

The channels 60 substantially have the function of allowing an even more uniform distribution of the air through the plate 58 of the diffuser 32, in particular in zones far from the inlet aperture 57.

The channels 60 are substantially disposed radially with respect to the peripheral portion 58a and the entrance aperture 57, therefore they converge toward said aperture 57, so that the air entering from the aperture 57 is uniformly distributed in the channels 60.

According to some embodiments, the channels 60 extend in a radial direction with respect to the peripheral portion 58a from an entrance end 60a, fluidly communicating with the entrance aperture 57, to an exit end 60b.

According to some embodiments, the channels 60 are equally distributed on the surface of the plate 58, so as to allow a uniform distribution of the air in the mass of water A to be treated.

According to some embodiments, the channels 60 are angularly distanced from each other in a uniform manner.

According to possible variants, the channels 60 are angularly offset with respect to each other in a differentiated manner between the peripheral portions and the central portion of the plate 58. For example, it can be provided that the channels 60 are denser in the central portion and more distanced in the peripheral portions.

According to other embodiments, as can be seen for example in fig. 5, the channels 60 can also have different lengths, that is, in the case of a circular plate 58 the channels 60 in the central zone can be longer than the channels 60 in the peripheral zones, so as to reach one or more points in proximity to the periphery. Each of the channels 60 can be formed for example by a pair of walls 61 suitably distanced from one another. The walls 61 are preferably parallel.

According to some embodiments, the height of each of the walls 61 defining the channels 60 progressively decreases along their length, proceeding from the entrance aperture 57 toward the periphery of the plate 58, hence from the inlet to the outlet of the air through said channels 60.

According to some embodiments, the walls 61 have a triangular-like shape decreasing between the entrance end 60a and the exit end 60b.

According to some solutions, the height of the walls 61 in correspondence with the ends disposed in proximity to the peripheral portion 58a of the plate 58, facing toward the aperture 57, is maximum, whereas, in correspondence with the opposite ends, the height of the walls 61 is minimum, or zero.

The progressive reduction in height of the walls 61 allows a gradual exit of the air from the channels 60, thanks to the action exerted by the hydrostatic pressure of the water A.

The initial height of the walls 61 can be established in conformity with the height, not visible in the drawing, of the air entrance aperture 57 in the diffuser 32.

According to some embodiments, the walls of adjacent respectively facing channels are joined together in correspondence with the entrance ends 60a of the channels 60, delimiting the entrance aperture 57, so that most of the air introduced through the inlet 21 enters into the channels and is distributed on the surface of the plate 58 and then in the mass of water A.

The air that exits from the diffuser 32 rises up through the layer of water A to be treated in the form of small bubbles, thanks, as we said, to the hydrostatic pressure of the water, saturating with humidity at the temperature of the mass of water to be treated.

The plate 58 can also be positioned with a certain slope, as shown in the drawings: the slope can be about 5-8° starting from the air entrance aperture 57. According to some embodiments, the portion of the plate 58 provided with the air entrance aperture 57 is located at a lower height than the portion of the plate 58 in a position diametrically opposite to it.

The slope can further promote the travel of the air along the plate 58 due to the hydrostatic pressure.

As can be seen, the diffuser 32 is positioned between the upper heat exchange device 28 and the lower heat exchange device 29.

The positioning of the diffuser 32 between the upper heat exchange device 28 and the lower heat exchange device 29 allows to prevent an ascending convective motion, which would occur during heating to reach the working temperature, that is, the treatment temperature of the water A. This convective motion would prevent the decanting of elements with a specific weight higher than that of water; in this way, instead, these elements are deposited on the bottom of the tank 12. The absorption of heat, in the present apparatus 10 or 1 1, is therefore obtained by the saturation with humidity of a mass of air which, forcibly and by means of the inlet 21, is sent into a mass of water A to be treated and contained inside the tank 12, which constitutes the "hot" part of the apparatus. The mass of air, in particular, is sent into the mass of water A to be treated through the diffuser 32.

What is obtained from the apparatus 10 or 1 1 is, in short, drinking water B which is preferably collected in a collection tank 22, located downstream of the condensation unit 16 or 16', and therefore downstream of the "cold" zone.

The apparatus 10 or 11 can also comprise a control and command unit, not shown for the sake of clarity of illustration, configured to regulate the functioning of the apparatus 10 or 1 1 at least to maintain the optimum temperature levels to make the water drinkable, adapting to the available energy conditions, for example according to the energies available from the primary heat generator 36 or 45 and from the secondary heat generator 37.

The control unit will therefore be associated with sensors to detect the level of fluids in the apparatus, to detect the temperature, pressure and others.

Moreover, the control unit can also be associated with the circulation pumps 40, 41, 44, 48 to regulate the flow rate of the fluids in the respective pipes according to the optimum temperatures and/or operating flow rates of the apparatuses 10 or 1 1.

It is clear that modifications and/or additions of parts can be made to the apparatus and method to make water drinkable as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of apparatus and method to make water drinkable, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

In the following claims, the sole purpose of the references in brackets is to facilitate reading: they must not be considered as restrictive factors with regard to the field of protection claimed in the specific claims.