Method and equipment for controlling the temperature of particles in polishing processes using solid particles

Abstract

The invention relates to a method and equipment for controlling the temperature of particles in polishing processes using solid particles and / or solid particles with an electrolyte, inside a container, said method comprising a step in which a gas is circulated through the environment between the particles located inside a container. Said method may further comprise a simultaneous or prior step of adjusting the chemical composition of the particles or their environment. The equipment comprises means for injecting a gas (3), which in some cases is preferably injected from the bottom of the container (1), said means comprising an aero-flotation device (4) and, optionally, also a moistening device (5) for suspending droplets of a liquid in said gas (3).

Description

OBJECT OF THE INVENTION

[0001] The invention, as stated in the title of this specification, relates to a method and to equipment for controlling the temperature of particles in polishing processes by means of solid particles, which provides advantages and features to the function for which it is intended and which are described later on in detail.

[0002] The object of the present invention relates to a method applicable to polishing processes or surface treatment of materials by means of solid particles, particularly relevant in electropolishing systems by means of solid particles loaded with an electrolyte and located inside a container, with the aim of controlling the temperature of the particles. During the polishing or electropolishing process by means of solid particles, a lack of temperature control may occur either due to the Joule effect generated during conduction of electrical current through the particles or the part to be polished, or due to friction or a combination of both effects. These temperature fluctuations can affect both the results of the surface treatment and the degradation of the solid particles, thereby reducing their useful life, affecting the conductivity and therefore the effectiveness of the treatment, which may no longer be homogeneous and / or repetitive.FIELD OF APPLICATION OF THE INVENTION

[0003] The field of application of the present invention falls within the industry sector dedicated to surface treatment, encompassing the industrial sector dedicated to the treatment of metal surfaces, with applications in any field, and particularly covering electropolishing processes by means of solid particles.BACKGROUND OF THE INVENTION

[0004] Methods for polishing surfaces in which the parts to be treated are polished by friction and / or through conductive particles incorporated into a container are known in the state of the art.

[0005] For example, document PCT / ES2017 / 070247 discloses a "Method for smoothing and polishing metals via ion transport by means of free solid bodies, and solid bodies for carrying out said method", which, after the connection of the parts to be treated to the positive pole (anode) of a current generator, includes the friction of the part with a set of particles made up of free electrically conductive solid bodies charged with a negative electrical charge and the introduction of said parts into a container or tank, in friction with a set of particles that are incorporated into said container and that contact electrically with the negative pole (cathode) of the current generator.

[0006] One problem associated with said method is that during the polishing process by means of solid particles containing an electrolyte inside a container or tank, the particles vary their temperature due to physical phenomena that occur during the surface treatment process, such as conduction of current or friction forces.

[0007] This variation in temperature may alter the result of the treatment and degrade the solid particles, causing a decrease in their useful life. Furthermore, a changein temperature also affects qualities such as conductivity, and therefore the polishing process, which depends on the conductivity of the process, is not homogeneous and / or repetitive. This means that, depending on the temperature of the particles, the polishing process is one or another, which may not be acceptable for the desired result in certain products.

[0008] Therefore, an objective of the present invention is the development of a method and equipment for controlling the temperature of particles.

[0009] The existence of temperature control systems in polishing systems, either by liquid recirculation or by direct contact by means of heat exchangers, is known.

[0010] By applying these methods in a polishing system by means of solid particle friction and / or conductive solid particles, it is not possible to achieve sufficient thermal control to ensure optimal, homogeneous, constant and repetitive results.

[0011] By applying thermal regulation by recirculating the product through a circuit through which heat is exchanged, as can be found in conventional electropolishing systems. In this case, there is a problem associated with the inability to pump the particles, since they are not inside a fluid that does not meet the features for the assembly to be pumpable. Given the difficulty in recirculation and the high probability of clogging the recirculation system, thermal control using this method is not possible.

[0012] The systems that the following invention applies to are defined by discrete media and do not exhibit physical continuity between the elements that form up, i.e., the particles. When attempting to carry out thermal control, introducing a resistive or conductive element that acts as a heat exchanger, either as a heat pump or refrigeration machine, by immersion into the system, the greatest difficulty encountered by the particles to transfer heat when compared to other liquid systems involves an ineffective and highly heterogeneous system. In the event that the solid particles are some types of ceramic or polymer materials, the efficiency of the thermal control process is reduced since they have a low thermal conductivity.

[0013] In the same way as previously described, thermal control by means of a heat exchanger system located at the periphery of the container is inefficient, since an excessive thermal gradient would be obtained from the centre to the periphery thereof.

[0014] The present invention aims to provide a method and mechanism with efficient temperature control that can be carried out prior to, during or after the surface treatment, and which overcomes the difficulties set out above.DESCRIPTION OF THE INVENTION

[0015] The present invention proposes a method applicable to polishing processes by means of solid particles and / or solid particles with an electrolyte, which purpose is to control the temperature of the polishing means. The present invention aims to generate the circulation of a gas through the interstitial environment between particles with the ability to adjust the temperature of both the medium and the particles. Furthermore, by circulating a gas through the interstitial environment between particles, it offers the possibility of adjusting the chemical composition of the particles and / or their environment by including micro-droplets of some liquid suspended in said gas.

[0016] An uncontrolled increase in the temperature produced in the process due to the Joule effect during conduction of current, which may degrade the particles, thereby reducing their useful life, and / or affecting the conductivity and therefore the effectiveness of the treatment, which may no longer be homogeneous and / or constant, for example, may be avoided by means of temperature control. In other situations, the temperature of the particles and / or their environment may be raised above the environmental conditions by means of temperature control, in order to find a more thermodynamically efficient condition that promotes greater particle kinetics or better polishing results.

[0017] The method and the aero-flotation equipment that are used for controlling the temperature of particles and their environment in polishing processes by means of solid particles proposed by the invention are configured as the ideal solution to the aforementioned objectives, where the characterising details that make it possible and that distinguish them are conveniently included in the final claims accompanying this description.

[0018] The aero-flotation equipment is defined as a mechanism by means of which the gas, with which the solid particles will be thermally controlled, is injected from the bottom of the container and with a homogeneous distribution in the expiratory pressure throughout the injection base.

[0019] As noted above, an embodiment of the invention proposes a method applicable to polishing processes by means of solid particles with an electrolyte therein and housed in a container, which purpose is to control the temperature of the polishing means, in some cases, preventing an uncontrolled increase in the temperature produced in the process due to, for example, the Joule effect that occurs during conduction of current, which may degrade the particles, thereby reducing their useful life, or affecting their conductivity and therefore the effectiveness of the treatment, which may no longer be homogeneous and / or constant.

[0020] In other embodiments of the invention, the objective of the method for controlling temperature is to increase the temperature of the particles and / or their environment above the environmental conditions in order to increase the thermodynamic efficiency of the process and promote greater kinetics, accelerating the surface treatment and / or obtaining better finishes.

[0021] Furthermore, in dry electropolishing systems by means of conductive solid particles, moisture, pH or the amount of acid or the presence of moderating liquids are also an important factor to ensure the conductivity of the dry electropolishing particles. Especially dry particles or particles with a low acid concentration do not offer as much conductivity as wet particles or particles with a higher acid concentration. It has been observed how temperature can disturb the initial chemical conditions mentioned above, which means that temperature control has a direct impact on the results of the surface treatment.

[0022] An embodiment method according to the present invention includes the circulation of a gas, in some cases preferably air, from the bottom of the container, such that it controls the temperature of the particles, further contemplating the possible application of hydration or impregnation of said particles in contact with the gaseous environment to avoid the reduction in moisture caused by said aero-flotation, either by spraying a liquid, such as water, onto the particles or injecting the gas with a high moisture or moistening content.

[0023] Furthermore, in a particular embodiment of the invention, aero-flotation equipment applicable to, for example, the bottom of a container of a polishing system by means of solid particles is used to carry out said temperature control method by means of, for example, injection of gas and hydration or impregnation of some liquid.

[0024] A method object of the invention comprises a step in which circulation of a gas is forced through the container, such that said gas circulates through the medium located between the particles, causing heat exchange through convention or other mechanisms between said gas and the particles and their environment, resulting in an adjustment of the working temperature. Based on the temperature difference between the gas and the medium containing the particles, it is possible to regulate the resulting temperature of said particles and said medium. It is possible to dynamically regulate the temperature of the circulation gas based on the reading of a sensor or thermocouple in contact with the particles, and thus dynamically adjust the working temperature.

[0025] The forced circulation of the gas in the interstitial medium is obtained in some cases by means of an injection process, in other cases by means aspiration, and in others, a combination of both effects.

[0026] As mentioned previously, the inlet of gas into the container with the particles is preferably carried out from the bottom. In other configurations, circulation of the gas is forced by means of perimeter injection along different heights in a container with any type of polygonal section. In another configuration, the gas is expelled through an element integral with the fastening system of the part, and which serves to move it within the polishing means, either focused on it or focused in other directions. In another configuration, recirculation is forced on the surface of the container containing the particles.

[0027] In one embodiment of the invention, in aero-flotation equipment, circulation of the gas through the particles is carried out from the lower part or bottom of the container, so that the gas rises and acts on the particles, cooling them. In addition to the thermal adjustment of the medium by means of convection, the gas injection process from the bottom of the container results in an increase in the partial pressure of said gas that is interposed in the medium between particles, which modifies their rheology and the pressure they exert when coming in contact with the part. All of this results in an additional reduction in the heat generated during polishing, modifying the aerodynamics of the polishing process and thus preventing the occurrence of defects on the part to be treated and improving the final polishing result. Greater fluidity of the assembly, thanks to this embodiment, promotes greater ease for the particles to adapt to the entire geometry of the part to be polished that moves inside the container, which prevents the occurrence of areas with a lesser surface finish due to downwind or turbulence. In turn, having a higher partial pressure of the gas injected into the interstitial space decreases the pressure exerted by the particles on the surface of the part, which results in a lower level of final attainable roughness.

[0028] More specifically, in a preferred embodiment, the gas is injected into a lower chamber through channels, preferably micro-perforated, and from this lower chamber it enters into the container with the particles through a membrane that closes the top of the chamber.

[0029] Thus, entry into the entire lower surface of the container is ensured and, therefore, temperature is controlled throughout the container.

[0030] Preferably, the gas injected into said system is generated by a compressed gas compressor. The method described in the invention is not limited to the fact that in another embodiment it is possible to recirculate the gas by suction carried out, for example, by a vacuum pump.

[0031] Thus, in a preferred embodiment of the invention, the equipment for controlling the temperature of particles in polishing processes by means of solid particles comprises means for injecting gas from the bottom of the container.

[0032] And, in one embodiment, preferably intended for polishing processes in a gaseous environment, said gas injection means comprise an aero-flotation device which, in turn, comprises a chamber made of PVC, or another material, in the form of a frame, suitable to fit in the bottom of the container, inside of which it has a blowing manifold with channels, preferably micro-perforated, that connect to an inlet duct for the gas driven under pressure from a compressor, and a very fine mesh membrane that closes the chamber at the top, which acts as a means for homogenising the gas that passes therethrough towards the container.

[0033] With this, when the chamber is filled, the membrane receives pressure and generates a cushion of gas throughout the base of the container that, when passing through, rises homogenised in the form of microspheres of gas that cool the particle content in the container.

[0034] Since it is a polishing process in which a gas is forced to circulate between the interstitial environment of the particles, this process can be carried out by injecting the gas with the help of a device that causes an aero-flotation effect, thanks to which a flow of cold gas is generated to displace the hot gas that, at the same time, produces heat exchange with the particles.

[0035] It is important to note that, since it is a polishing process in a gaseous environment, the gas, which can be any other gas, dries the particles and causes an endothermic reaction that captures the heat of the particles, thus lowering the temperature but also removing moisture from them.

[0036] To counteract this reduction in moisture caused by the injection of gas, since, as mentioned in previous sections, moisture is also an important factor to ensure the conductivity of the particles and if they are especially dry, they do not offer as much conductivity as the wet particles, the method object of the invention preferably contemplates a simultaneous or prior step of hydrating the particles.

[0037] In an embodiment option, said step of hydrating the particles is carried out simultaneously with the injection of gas by spraying a liquid, such as water, onto the particles in the container or tank, by means of injectors oriented towards the inside of the container, preferably located on the container.

[0038] And, in another embodiment option, hydration is carried out by injecting the gas, such as air, with a high moisture content.

[0039] Therefore, a secondary objective of the invention is to provide a method and equipment for controlling the temperature of particles by injecting gas that, at the same time, ensures correct control of electrochemical conditions, such as moisture, pH, additives thereof to avoid an excess or deficit of conductivity and / or galvanic capacity when the process is carried out in a gaseous environment.

[0040] For this, preferably, prior to injecting gas into the container, said gas is injected into a vessel with a liquid, preferably water, the gas passes through the vessel with the liquid, gaining moisture, and then it is injected into the container with the particles.

[0041] In another embodiment, said hydration process can be complemented with an acid dissolved in a polar liquid, such as water, in such a way that it also allows its pH to be controlled, the acid being, for example, sulphuric acid, sulphonic acid, hydrochloric acid, hydrofluoric acid, phosphoric acid, nitric acid.

[0042] In another embodiment of the invention, the liquid suspended in the gas is a non-conductive additive or element, such as some type of oil, which acts as a moderator of the conductivity or the electrochemical interaction between the particles and the part, preventing, for example, the occurrence of uncontrolled chemical attacks on the part. Said additives can be non-polar liquids such as short aliphatic chains. The moderating liquids can incorporate surfactants in their presence that modify the interactive capacity between particles and between the particles and the surface to be treated.

[0043] Furthermore, in one embodiment, the equipment object of the invention for controlling the temperature of particles in polishing processes by means of solid particles in a gaseous environment further comprises a device for hydrating the compressed gas that is injected into the aforementioned aero-flotation device which, preferably, comprises a column filled with a liquid, such as water, through which the gas is circulated prior to its injection into the chamber at the bottom of the container, so that it is hydrated, since it is converted into gas with a high moisture content or the other types of liquids described above.

[0044] In one embodiment, at the bottom of said liquid column, where the end of the gas inlet duct is inserted into the same, the incorporation of a filter is provided to generate micro gas bubbles that, when they rise, capture micro-droplets of liquid, altering their composition, such as increasing their moisture content and directing the gas towards the container.

[0045] There are gases other than air that can be used to carry out the invention. Inert gases, without having the capacity to react thermodynamically or electrochemically with the part, such as nitrogen (N), argon (Ar), helium (He), neon (Ne), krypton (Kr), xenon (Xe), carbon dioxide (CO 2 ) or any combination thereof, can be used.

[0046] It is possible to use other types of gases that have a high convective capacity, in combination with properties such as viscosity, vapour pressure or heat capacity, although they may react with the particles or the part to be treated; such as acetylene, hydrogen sulphide, ammonia, carbonic anhydride, sulphurous anhydride, ethane, ethylene, isobutane, methane, nitric oxide, nitrous oxide, oxygen, propane, etc.

[0047] In some embodiments, such as those described above, in which work is carried out with different gases or with different liquids suspended in said gases, work is carried out in a sealed chamber and in a controlled atmosphere. The different partial pressures, moisture, vapour pressure, dew point temperature of the atmosphere, among other thermodynamic properties, can be modified in order to obtain better control or stability of the chemical conditions in which the particles are located.DESCRIPTION OF THE DRAWINGS

[0048] To complement the description being made and to make the features of the invention more readily understandable, drawings are attached to the present specification as an integral part thereof, in which the following is depicted in an illustrative and non-limiting manner: Figure 1 shows a schematic top plan view of a container used in a polishing process by means of solid particles, in which an example of the aero-flotation device comprising equipment for controlling the temperature of particles object of the invention has been incorporated as a means for injecting a gas, said container being incorporated in an outer cooling jacket; figures 2-A and 2-B show respective section views according to the section A-A indicated in figure 1, of a container with an aero-flotation device of the invention, represented in the rest phase and in operating phase, respectively; figure 3 shows a schematic perspective view of an example of the aero-flotation device comprising the equipment, according to the invention, in this case represented independently, without being incorporated into the container, showing its general outer configuration; figure 4 shows a schematic perspective view of an example of a chamber comprising an aero-flotation device shown in figure 3; figure 5 shows a schematic perspective view of an example of a network of gas channels that comprises an aero-flotation device shown in figure 3 incorporated inside the chamber, showing its configuration; figure 6 shows a schematic perspective view of an example of a membrane comprising a possible aero-flotation device shown in figure 3 incorporated on a chamber, showing its configuration; and figures 7-A and 7-B show respective schematic and section views of an example of the device for suspending micro-droplets of chemicals in liquid format in the gas, said device comprising the equipment of the invention, represented in the rest phase and in the operating phase, respectively, showing the main parts it comprises. PREFERRED EMBODIMENT OF THE INVENTION

[0049] In view of the aforementioned figures, and in accordance with the numbering adopted, a non-limiting exemplary embodiment of the equipment for controlling the temperature of particles in polishing processes by means of solid particles of the invention is shown, which comprises what is described in detail below.

[0050] As shown in said figures, the equipment under consideration, particularly applicable to polishing processes by means of solid particles and / or solid particles with an electrolyte (2) inside a container (1), comprises means for injecting gas (3), such as air from the bottom of the container (1).

[0051] More specifically, in one embodiment of the invention, the gas injection means (3) comprise at least an aero-flotation device (4) which, in turn, comprises a chamber (40) suitable to fit in the bottom of the container (1), a gas blowing manifold (41), incorporated inside the chamber and connected to a gas inlet duct (42), and a membrane (43) that closes the chamber (40) at the top so that, when filled with pressurised gas, it generates a cushion of gas (3) throughout the base or bottom of the container (1) that, when passing through the membrane (43), rises in the form of homogeneous chambers of gas (3), thermally adjusting the particle content and their environment (2) in the container (1), as shown in figures 2-A and 2-B.

[0052] In a particular embodiment of the invention, as shown in figure 4, the chamber (40) of the aero-flotation device (4) has a lower base (400) with a perimeter partition (401) that, as a support ring, adapts to the shape of the bottom of the container (1), for example circular, and defines a central housing (402) for accommodating the blowing manifold (41), the assembly being closed at the top by the membrane (43).

[0053] In a possible embodiment, the chamber (40) is a part made of PVC, although other materials, preferably non-conductive, are not ruled out without restricting the use of conductive materials.

[0054] Preferably, as shown in figure 5, the blowing manifold (41) is formed by a circuit of micro-perforated rubber tubes (410) that, joined together by means of two or three-way interconnections (411), form a perimeter frame, where one of said interconnections (411) connects to the gas inlet duct (42), and several central branches with closed distal ends, so that the gas only emerges through the micro-perforations.

[0055] Said perforations have a diameter measuring between 10 µm and 10 mm, preferably between 100 µm and 2 mm, more preferably between 500 µm and 1 mm.

[0056] The gas entering through the inlet duct (42) is injected under pressure from a gas compressor not represented.

[0057] Furthermore, the membrane (43) that closes the chamber (40) at the top is preferably an AISIS 316 fine mesh of 100 µm on a support made of plastic material, for example, PVC (polyvinyl chloride) or PVDF (polyvinylidene fluoride), or made of rubber material, such as NBR (nitrile butadiene rubber).

[0058] Figures 7-A and 7-B show how, in one embodiment, the equipment of the invention further comprises a hydration device (5) to increase the moisture in the compressed gas (3) prior to it being injected into the aero-flotation device (4).

[0059] A possible hydration device (5) comprises, for example, a column (50), which defines a container closed at the top with a lid (51) and which is filled with some liquid, preferably water, through which gas (3), preferably air, is circulated through a gas inlet tube (52), which outlet mouth (520), or outlet opening of the dry gas (3), is located at the bottom of the column (50), and a gas outlet tube (53), which inlet mouth (530), or inlet opening of the hydrated gas (3'), is located at the top of the column (50), above the liquid level.

[0060] Thus, the gas once moistened (3') is injected from the outlet tube (53), once connected to the inlet duct (42), towards the aero-flotation device (4).

[0061] In a possible embodiment, at the outlet mouth (520) of the inlet tube (52) of non-moistened gas (3) at the bottom of the column (50) with the liquid, the incorporation of a filter (54) is provided to generate micro bubbles.

[0062] Optionally, the container (1), as shown in figures 1 and 2-A, 2-B, is incorporated inside a cooling jacket (6) that surrounds it externally and has a cooling fluid inlet (61) at the bottom and a cooling fluid outlet (62) at the top.

[0063] Having sufficiently described the nature of the present invention, as well as how to implement it, it is not considered necessary to further explain it so that any person skilled in the art can understand its scope and the advantages derived from it.

Claims

1. A method for controlling the temperature of solid particles and / or solid particles with an electrolyte therein, and their environment, during surface treatment of metals, in which the solid particles are inside a container to maintain the desired thermal adjustment to said particles and their environment, avoiding an unwanted evolution of the temperature produced by some physical phenomenon, such as the Joule effect or friction, characterised in that it comprises: - a step in which a gas is injected into the container, such that said gas circulates between the particles inside the container, causing a temperature exchange between the gas, the particles and their medium.

2. The method for controlling the temperature of particles in polishing processes by means of solid particles, according to claim 1, characterised in that the gas with which heat exchange takes place is air.

3. The method for controlling the temperature of particles in polishing processes by means of solid particles, according to any of the preceding claims, characterised in that the gas injected is at a temperature lower than that of the process.

4. The method for controlling the temperature of particles in polishing processes by means of solid particles, according to any of the preceding claims, characterised in that the injection of gas is carried out from the lower part or bottom of the container.

5. The method for controlling the temperature of particles in polishing processes by means of solid particles, according to claim 4, characterised in that the injection of gas is carried out by means of an aero-flotation device, which causes less compaction between the solid particles, by generating a flow of gas that filters through the medium in which the particles are located and, at the same time, exchanges heat with particles.

6. The method for controlling the temperature of particles in polishing processes by means of solid particles, according to any of the preceding claims, characterised in that it includes a step of controlling the chemical composition of the particles and / or their environment by suspending micro-droplets of some liquid in the heat exchange gas.

7. The method for controlling the temperature of particles in polishing processes by means of solid particles, according to claim 6, characterised in that it comprises a step of hydrating the particles simultaneously with the injectionof gas, by spraying a sprayed polar liquid.

8. The method for controlling the temperature of particles in polishing processes by means of solid particles, according to claim 7, characterised in that the spraying of polar liquid onto the particles is carried out by means of injectors located on the container.

9. The method for controlling the temperature of particles in polishing processes by means of solid particles, according to claim 6, characterised in that the step of hydrating the particles is carried out by injecting the gas in question with a high moisture content.

10. The method for controlling the temperature of particles in polishing processes by means of solid particles, according to claim 9, characterised in that, prior to injecting gas into the container, said gas is injected into a hydration device (5) to increase the moisture in the gas (3).

11. Equipment for controlling the temperature of solid particles and / or solid particles with an electrolyte therein during surface treatment of metals inside a container that allows adjusting the temperature of the particles and their environment, avoiding an unwanted evolution of the temperature produced by some physical phenomenon, such as the Joule effect or friction, characterised in that it comprises means for circulating a gas (3) through the medium between particles (2).

12. The equipment for controlling the temperature of particles in polishing processes by means of solid particles, according to claim 11, characterised in that the means for circulating a gas (3) include the injection of gas and comprise at least an aero-flotation device (4) which, in turn, comprises a chamber (40) suitable to fit in the bottom of the container (1), a gas blowing manifold (41), incorporated inside the chamber and connected to a gas inlet duct (42), and a membrane (43) that closes the chamber (40) at the top so that, when filled with pressurised gas, it generates a cushion of gas (3) throughout the base or bottom of the container (1) that, when passing through the membrane (43), rises in the form of homogenised compartments of gas (3), exchanging heat with the particle content and their environment (2) inside the container (1).

13. The equipment for controlling the temperature of particles in polishing processes by means of solid particles, according to claim 12, characterised in that the chamber (40) of the aero-flotation device (4) has a lower base (400) with a perimeter partition (401) that, as a support ring, adapts to the shape of the bottom of the container (1), and defines a central housing (402) for accommodating the blowing manifold (41), the assembly being closed at the top by the membrane (43).

14. The equipment for controlling the temperature of particles in polishing processes by means of solid particles, according to claim 12 or 13, characterised in that the chamber (40) is a part made of a non-conductive material.

15. The equipment for controlling the temperature of particles in polishing processes by means of solid particles, according to any of claims 12 to 14, characterised in that the blowing manifold (41) is formed by a circuit of micro-perforated tubes (410).

16. The equipment for controlling the temperature of particles in polishing processes by means of solid particles, according to any of claims 11 to 14, characterised in that the membrane (43) that closes the chamber (40) at the top is a fine mesh.

17. The equipment for controlling the temperature of particles in polishing processes by means of solid particles, according to any of claims 12 to 15, characterised in that it further comprises a moistening device (5) to incorporate micro-droplets of a fluid into the compressed gas (3) prior to it being circulated through the aero-flotation device (4).

18. The equipment for controlling the temperature of particles in polishing processes by means of solid particles, according to claim 17, characterised in that the hydration device (5) comprises at least one column (50), which defines a container closed at the top with a lid (51) and which is filled with a liquid, with an inlet tube (52) of gas (3), which outlet mouth (520) is located at the bottom of the column (50), and an outlet tube (53) of gas (3), which inlet mouth (530) is located at the top of the column (50), above the liquid level.

19. The equipment for controlling the temperature of particles in polishing processes by means of solid particles, according to claim 18, characterised in that, at the outlet mouth (520) of the inlet tube (52) of gas (3) at the bottom of the column (50) with the liquid, the incorporation of a filter (54) is provided.

20. The equipment for controlling the temperature of particles in polishing processes by means of solid particles, according to any of claims 12 to 19, characterised in that the container (1) is incorporated inside a cooling jacket (6) that surrounds it externally and has a cooling fluid inlet (61) at the bottom and a cooling fluid outlet (62) at the top.

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