METHOD AND PLANT FOR COOLING A MIXTURE OF INGREDIENTS OF CONCRETE

Abstract

A method and plant for cooling a mixture of concrete, includes: loading in a hermetically sealed tank a given quantity of ingredients to form the concrete, the ingredients including a predetermined quantity of water; regulating the pressure in the tank to obtain a transitory degree of vacuum in the tank; regulating the pressure inside a hermetically sealed condensation chamber to obtain a basic degree of vacuum in the condensation chamber that is greater than the transitory degree of vacuum, such that the pressure in the condensation chamber is lower than the pressure in the tank; operatively connecting the tank and the condensation chamber to substantially equalize the internal pressure in the tank and in the condensation chamber to a resulting degree of vacuum and to cause at least partial evaporation of the water from the tank towards the condensation chamber to lower the temperature of the ingredients in the tank.

Claims

1. Method for cooling a mixture of ingredients of concrete, comprising: loading in a first hermetically sealed tank (1) a first given quantity (Q of ingredients at a first initial temperature (Tin1), said ingredients being intended to form said concrete and comprising a first predetermined quantity of water; regulating a pressure in said first tank (1) so as to obtain a first transitory degree of vacuum (Ptl) in said first tank (1); regulating a pressure inside a hermetically sealed condensation chamber (4) so as to obtain a basic degree of vacuum (P2) in said condensation chamber (4) that is greater than the first transitory degree of vacuum (Pt!), such that the pressure in the condensation chamber (4) is lower than the pressure in the first tank (1); operatively connecting the first tank (1) and the condensation chamber (4) so as to substantially equalize the Internal pressure in the first tank (1) and in the condensation chamber (4) to a resulting degree of vacuum (P3) and to cause at least partial evaporation (yap) of the water from the first tank (1) towards the condensation chamber (4) so as to lower the temperature of said ingredients in the first tank (1); condensing in the condensation chamber (4) the water evaporated from the first tank (1); conveying the condensed water (con) from the condensation chamber (4) to the first tank (1) so as to keep said predetermined first quantity of water in the first tank (1) substantially unvaried; and collecting said ingredients from the first tank (1) at a first output temperature (Toutl) lower than said first initial temperature (Tint),

2. Method for cooling a mixture of ingredients of concrete, comprising: loading in a first tank (1′) of a plurality of hermetically sealed tanks (1′, 2′, 3′, 200′) a first quantity (Q1) of ingredients at a first initial temperature (Tin1) said ingredients being intended to form said concrete, said ingredients comprising a first predetermined quantity of water; operatively connecting the first tank (1′) and a second tank (2′) of said plurality of hermetically sealed tanks (200′) so as to substantially equalize the internal pressure in the first tank (1′) and in the second tank (2′) to a residual degree of vacuum (Pr), the first tank (1′) having an initial internal pressure degree equal to atmospheric pressure (Patm), the second tank (2′) having an initial internal pressure degree lowerthan atmospheric pressure (Patm); loading in the second tank (2′) a second quantity (Q2) of ingredients at a second initial temperature (Tin2), said ingredients being intended to form said concrete, said ingredients comprising a second predetermined quantity of water; regulating the pressure inside the first tank (1′) so as to obtain a first transitory degree of vacuum (Ptl) in the first tank (1′); regulating a pressure inside a hermetically sealed condensation chamber (4′) so as to obtain a basic degree of vacuum (P2) in said condensation chamber (4′) that is greater than the first transitory degree of vacuum (Ptl), such that the pressure in the condensation chamber (4′) is lower than the pressure in the first tank (1′); operatively connecting the first tank (1′) and the condensation chamber (4′) so as to substantially equalize the internal pressure in the first tank (1′) and in the condensation chamber (4′) to a resulting degree of vacuum (P3) so as to cause at least partial evaporation (vap) of the water contained in the first tank (1′) towards the condensation chamber (4′) so as to lower the temperature of said ingredients in the first tank (i′); condensing in the condensation chamber (4′) the water evaporated from the first tank (1); operatively connecting the first tank (1′) and the second tank (2′) so as to substantially equalize the internal pressure in the first tank (1′) and in the second tank (2′) to a further residual degree of vacuum (PO, the second tank (2′) having an initial internal pressure degree equal to the atmospheric pressure (Patm).sub.; the first tank (1′) having an initial internal pressure degree lower than the atmospheric pressure (Patm); collecting said ingredients from the first tank (1′) at a first output temperature (Toutl) lower than said first initial temperature (Tin1),

3. The method according to claim 2, further comprising a starting phase which comprises; operatively connecting each tank (l′-3′) of said plurality of hermetically sealed tanks (200′) and said hermetically sealed condensation chamber (4′); regulating the pressure inside the hermetically sealed (200′) tanks (l′-3′) and inside the condensation chamber (4′) so as to obtain an initial homogenous degree of vacuum.

4. The method according to claim 2, further comprising conveying the condensed water (con) from the condensation chamber (4′) to the first tank (1′) and to the second tank (2′) so as to keep said respective first and second predetermined quantity of water unvaried.

5. The method according to claim 2 wherein the method further comprises operatively connecting the first tank (1′) and the second tank (2′) to a single cyclical vacuum source (7′) configured to regulate the internal pressure in the first tank (1′) and in the second tank (2′).

6. Method The method according to claim 1, wherein the method further comprises mixing the ingredients of the concrete in at least one of: the first tank (1′) the second tank (2′).

7. Plant (100) for cooling a mixture of ingredients of concrete, comprising: a first hermetically sealed tank (1) configured to receive a given quantity (Q1) of ingredients at a first initial temperature (Tin1), said ingredients being intended to form said concrete, said ingredients comprising a predetermined quantity of water; a condensation system (4, 41, 5) in order to condense the water evaporated from the first tank (1), said condensation system comprising a condenser (41) and a hermetically sealed condensation chamber (4) configured to collect said evaporated water; at least one interconnection valve (11) configured to operatively connect said first tank (1) to said condensation chamber (4); at least one vacuum source (6, 7) in order to regulate the internal pressure in the condensation chamber (4) and in the first tank (1); a recycling pipe (10) configured and intended for conveying the condensed water (con) from the condensation chamber (4) to the first tank (1) so as to keep said predetermined quantity of water in the first tank (1) substantially unvaried.

8. The plant (100) according to claim 7, wherein said at least one vacuum source (6, 7) comprises a basic vacuum source (6) and a cyclical vacuum source (7) which are designed to regulate pressure in the condensation chamber (4) and in the first tank (1), respectively.

9. Plant (100) for cooling a mixture of ingredients of concrete, comprising: a plurality of hermetically sealed tanks (200′), each tank of said plurality of hermetically sealed tanks (1′, 2′, 3′) being designed to receive a respective quantity (Q1, 02) of ingredients for forming said concrete at a relevant first initial temperature (Tin1, Tin2), said ingredients comprising a respective first and second predetermined quantity of water; a condensation system (4′ 41′, 5′) in order to condense the water evaporated from the tanks (1′, 2′, 3′) of said plurality of hermetically sealed tanks (200′), said condensation system comprising a condenser (41′) and a hermetically sealed condensation chamber (4′) configured to collect said evaporated water(yap); at least one interconnection valve (11′) in order to operatively connect said condensation chamber (4′) to each of the tanks of said plurality of tanks, in order to make the evaporated water (vap) flow from the first tank (1′) or from the second tank (2′) to the condensation chamber (4′); at least one vacuum source (6′, 7′) in order to regulate the internal pressure in the condensation chamber (4′) and in the tanks of said plurality of tanks (200′); at least one equalization valve (12′) configured and intended for operatively connecting a first tank (1) and a second tank (2′) of said plurality of tanks (200′) so as to substantially equalize the internal pressure in said first tank (1′) and said second tank (2).

10. The plant (100′) according to claim 9, further comprising a recycling pipe (10′) for each tank of said plurality of tanks (200′), said pipe conveying the condensed water (con) from the condensation chamber (4′) to a relevant tank of said plurality of tanks (200′) so as to keep said predetermined quantity of water substantially unvaried.

11. The plant (100′) according to claim 10, wherein the recycling pipe (10′) of a tank of said plurality of tanks (200′) comprises an upper opening (42′) positioned below a heat exchange portion (43′) inside said condensation chamber (41 said recycling pipe (10′) being able to convey the evaporated water (yap) through said interconnection valve (11′) from said tank towards said heat exchange portion (43′) of said condenser (41′), said heat exchange portion (43′) being dedicated to exclusively condensing the evaporated water (yap) from said tank and conveyed by said recycling pipe (101 said upper opening (42′) being able to receive the condensed water (con) exclusively from said heat exchange portion (43′) so as to convey it once more to said tank.

12. The plant (100; 100′) according to claim 7, wherein said first tank (1; 1′) or said second tank (2′) of said plurality of hermetically sealed tanks (200′) comprises a mixer (9; 9′) designed to mix the ingredients of the concrete inside the relevant tank (1; 1′, 2′).

13. The plant (100; 100′) according to claim 7, further comprising at least one gap (16; 16′) positioned so as to be interposed between an outer wall of a tank (1; 1′-3′) and a mixer (9; 9′) placed inside said tank (1; 1′-3′), or interposed between said condenser (41; 41′) and an outer wall of said condensation chamber (4; 4′), said gap (16; 16′) being able to be depressurized so as to thermally insulate said mixer (9; 9′) or said condenser (41; 41′).

14. The plant (100; 100′) according to claim 7, wherein the capacity of said first tank (1; 1′) is between 0.3 and 0.7 m.sup.3.

15. The plant (100) according to claim 9, wherein each tank (1′-3′) of said plurality of hermetically sealed tanks (200′) has substantially the same capacity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0113] The characteristics and advantages of the invention will become more apparent from the detailed description of preferred embodiments, illustrated by way of non-limiting example, with reference to the appended drawings in which:

[0114] FIGS. 1 and 2 are perspective views of the plant for cooling a mixture of ingredients of concrete according to an embodiment of the present invention;

[0115] FIG. 3 is a block diagram of the cooling plant in FIG. 1 and 2; and

[0116] FIG. 4 is a block diagram of the plant for cooling a mixture of ingredients of concrete according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0117] The appended figures show a cooling plant 100 for cooling a mixture of ingredients of concrete according to the present invention.

[0118] The cooling plant according to the invention is suitable for cooling a mixture of ingredients of concrete using the latent heat of evaporation of water.

[0119] “Mixture of ingredients of concrete” means a mixture with a desired quantity of construction aggregate materials (such as, for example, sand, gravel, crushed stone), binding agent (for example cement) and water, which are loaded together into a hermetically sealed tank. In particular, the water is present in said mixture of ingredients of the concrete in a predetermined quantity so as to comply with the proportion of water or the ratio of water to cement indicated by a recipe of the concrete.

[0120] FIGS. 1-3 show a cooling plant 100 according to the invention, comprising a first hermetically sealed tank 1 which is designed to contain a given quantity of mixture of ingredients for forming the concrete.

[0121] The plant 100 comprises a first tank 1, a cooler 5, a condensation chamber 4 and a condenser 41 arranged inside the condensation chamber 4 and operatively connected to the cooler 5. In addition, 6 indicates a basic vacuum source, which is operatively connected to the condensation chamber 4, and 7 indicates a cyclical vacuum source, which is operatively connected to the tank 1. The plant 100 also has interconnection valves 11, which are configured to operatively connect the first tank 1 and the condensation chamber 4.

[0122] Preferably, the plant 100 is structurally and functionally designed such that the condensation chamber 4 is arranged above the first tank 1. Advantageously, this arrangement allows to take advantage of the force of gravity in order to facilitate the recycling of the condensation water from the condensation chamber 4 to the first tank 1 via a recycling pipe 10, as explained better hereinafter. According to one aspect, the first tank 1 is provided with at least one loading mouth and at least one discharge mouth.

[0123] The first tank 1 can have a hopper 14 to facilitate the operation of loading the ingredients of the mixture of ingredients of the concrete into the first tank 1,

[0124] In a phase of starting the plant 100, the cooler 5 is switched on and time is allowed for the desired cooling temperature to be reached.

[0125] In regular operation, a first quantity Q1 of ingredients of the concrete is poured into a first tank 1 at an initial temperature Tin1. Said initial temperature Tin1 is a mean temperature of the ingredients which are poured into the first tank 1 and depends on the temperature of the individual ingredients.

[0126] Preferably, loading the first tank 1 requires said tank to have the discharge mouth closed and the loading mouth open.

[0127] In operation, the pressure is regulated in said first tank 1 so as to obtain a first transitory degree of vacuum Ptl in the first tank 1.

[0128] In addition, the pressure inside the hermetically sealed condensation chamber 4 is regulated so as to obtain in said condensation chamber 4 a basic degree of vacuum P2 greater than the first transitory degree of vacuum Ptl, i.e., such that the pressure in the condensation chamber 4 is lower than the pressure in the first tank 1.

[0129] It is also necessary to operatively connect the first tank 1 and the condensation chamber 4 so as to substantially equalize the internal pressure in the first tank 1 and in the condensation chamber 4 to an intermediate degree of vacuum P3, and to cause at least partial evaporation “vap” of the water from the first tank 1 towards the condensation chamber 4, so as to lower the temperature of said ingredients in the first tank 1. The evaporation of the water comprises the extraction of a quantity of energy corresponding to the latent heat of evaporation of the water, and therefore comprises cooling the ingredients of the concrete which are inside the tank 1.

[0130] According to one aspect, the equalization of the pressure between the first tank 1 and the condensation chamber 4 takes place by means of the effect of opening the interconnection valves 11. Preferably, the equalization of the pressure and the evaporation of the water take place via the open interconnection valves 11.

[0131] The water vapor obtained from the evaporation of the water in the ingredients in the tank 1 reaches the condensation chamber 4 containing the condenser 41 which is maintained at a condensation temperature by means of the cooler 5. The water vapor in the condensation chamber 4 which is in contact with the condenser 41 at the condensation temperature precipitates as condensed water “con” and would tend to collect in the condensation chamber.

[0132] Preferably simultaneously, the condensed water “con” is conveyed from the condensation chamber 4 to the first tank 1 so as to keep the first predetermined quantity of water in the first tank 1 substantially unvaried. Preferably, this recirculation of the condensation water takes place via the recycling pipe 10. According to an advantageous aspect, the recycling pipe 10 makes it possible to collect the condensation water “con” and convey it so as to keep the condenser 41 isolated from the heat from the external environment. According to a further advantageous aspect, the recycling pipe 10 makes it possible to convey the evaporated water “vap” through the interconnection valve 11 from the first tank 1 to the condensation chamber 4, and also makes it possible to collect the condensation water “con” and convey it once more to the first tank 1. According to one aspect, the first tank 1 comprises a valve which is configured to eliminate the residual degree of vacuum inside the first tank 1, once the cooling cycle has ended inside said first tank 1. In practice, said valve equalizes the internal pressure in the first tank 1 and the external atmospheric pressure. Advantageously, the elimination of the residual degree of vacuum permits the opening of the discharge mouth of the first tank 1.

[0133] At the end of the cooling process, the ingredients are collected from the first tank 1 at an output temperature Toutl lower than said first initial temperature Tin1, said first output temperature Toutl being the mean temperature of the material collected from the first tank 1.

[0134] The first output temperature Toutl can be between 5° C. and 25° C., on the basis of parameters of influence such as the thermal inertia and the quantity of material introduced into the first tank, the initial temperature of said material, and the quantity of water evaporated/condensed during the process.

[0135] According to preferred embodiments, the condenser 41 receives cooled water from the cooler 5.

[0136] According to one aspect, the plant 100 comprises an accumulation tank 13 which is operatively connected to the cooler 5 and to the condenser 41. The accumulation tank 13 can be configured to receive the water cooled by the cooler 5 and admit it into the condenser 41.

[0137] Advantageously, the accumulation tank 13 makes it possible to prevent continuous rapid variations of temperature in the cooled water as a result of the intermittence of the regulation. According to a further advantageous aspect, the accumulation tank 13 makes it possible to limit the number of times a compressor of the cooler 5 is switched on/off per hour to an acceptable value, especially in the conditions in which the cooling process is stopped, deliberately or unintentionally, and it is necessary to ensure that the cooler 5 has a certain stability of operation. This is obtained thanks to a quantity of stored water contained in the accumulation tank 13.

[0138] According to another embodiment shown in FIG. 4, the accumulation tank 13′ is configured to receive the water from the condenser 41′ and to admit the water into the cooler 5′ so as to guarantee that the cooler 5′ continuously has a head of water.

[0139] According to one aspect, the ingredients of the mixture of ingredients of the concrete are mixed, i.e., kneaded so as to amalgamate them and form a concrete mix. According to one aspect, the plant 100 comprises a mixer 9 which can produce said concrete mix from the mixture of ingredients of the concrete. Preferably, as shown in FIG. 3, the mixer 9 is placed inside the first tank 1 so as to mix or knead said mixture during the cooling process. This solution makes it possible to reduce the times required for the production of the concrete mix ready for casting. Advantageously, the plant 100 permits cooling of the construction aggregates or of the concrete already produced, or of the roller-compacted concrete (RCC).

[0140] FIG. 4 shows an alternative embodiment of a cooling plant 100′ according to the invention, in which parts corresponding to those previously described will be indicated with the same reference numerals provided with an apostrophe and will not be described in detail.

[0141] In the embodiment in FIG. 4, the plant 100′ comprises a plurality of tanks 200′, each tank of the plurality of tanks 200′ being designed to receive the ingredients of the mixture of concrete to be cooled.

[0142] The plurality of tanks 200′ comprises at least one first tank 1′ and one second tank 2′ and one third tank 3′. According to other versions not shown, a different number of tanks can be provided which is more than or equal to two.

[0143] The tanks are interconnected to one another by means of equalization valves 12′ so as to permit recycling of the residual vacuum from one tank to another. Preferably, each hermetically sealed tank of the plurality of tanks 200′ is provided with an equalization valve 12′, which is dedicated to operatively connecting the tank to one or more of the other hermetically sealed tanks.

[0144] In addition, the plant 100′ comprises the condensation chamber 4′ and an interconnection valve 11′ interposed between the condensation chamber 4′ and each tank 1′-3′ of the plurality of tanks 200′.

[0145] According to one aspect, inside the condensation chamber 4′ a single condenser 41′ is provided which can condense the evaporated water “vap” from each tank l′-3′ of the plurality of hermetically sealed tanks 200′, instead of a separate condenser for each tank. This arrangement makes it possible to reduce the plant costs, since it comprises adopting a single condenser 41′, a single water pump 51′ for the cooling circuit of said condenser 41′, and a single basic vacuum source 6′ in order to depressurize the condensation chamber 4′. According to one version, the basic vacuum source 6′ can comprise a plurality of vacuum pumps, such as, for example, three vacuum pumps, so as to permit the use of a larger-sized condenser 41′. According to a further advantageous aspect, the use of a single larger-size condenser 41′ makes it possible to increase the energy efficiency, thanks to the reduction of the losses of load, such as, for example, the losses of load through a tube bundle of the condenser, and it also makes it possible to reduce the energy consumption thanks to the larger extent of the surface area for heat exchange, such as, for example, the heat exchange surface area of said tube bundle for the same quantity of cooled water passing through the condenser itself.

[0146] Advantageously, each tank l′-3′ is provided with a mouth for loading ingredients of the concrete to be cooled, and with a mouth for discharging the cooled concrete, neither of the two being shown in the figures.

[0147] The method for cooling the concrete implemented on the plant 100′ provided with the plurality of tanks 200′ comprises operating the following cycle.

[0148] In a starting phase, the cooler 5′ is switched on, and time is allowed for the cooler to reach the desired temperature, and in the meantime the pressure is regulated inside the plurality of hermetically sealed tanks 200′ and inside the condensation chamber 4′ so as to obtain an initial degree of vacuum.

[0149] Preferably, the tanks of the plurality of hermetically sealed tanks 200′ and the condensation chamber 4′, which is also hermetically sealed, are operatively connected to one another so as to obtain a single environment with a substantially homogenous internal pressure. In practice, the interconnection valves 11′ and the equalization valves 12′ are opened in order to operatively connect the tanks l′-3′ of the plurality of hermetically sealed tanks 200′ and the condensation chamber 4′ to one another.

[0150] In addition, the tanks 1′-3′ are advantageously closed in a sealed manner in order to isolate them from the external environment, and the pressure is regulated inside the tanks 1′-3′ of the plurality of hermetically sealed tanks 200′ and inside the condensation chamber 4′ so as to obtain a homogenous initial degree of vacuum inside said environment of the tanks The homogenous initial degree of vacuum is obtained by means of the basic vacuum source 6′ or the cyclical vacuum source 7′ and can correspond to a pressure value which for example is equal to 10 millibar.

[0151] The closure of the interconnection valves 11′ and of the equalization valves 12′ concludes the starting phase.

[0152] A first quantity Q1 of ingredients at a first initial temperature Tin1 is then loaded into the first tank 1′, said ingredients being intended to form said concrete, said ingredients comprising a first predetermined quantity of water.

[0153] The first initial temperature Tin1 represents a mean temperature which depends on the temperature of the individual ingredients of the concrete. At this point, the first tank 1′ and the second tank 2′ are operatively connected so as to substantially equalize the internal pressure in the first tank 1′ and in the second tank 2′ to a residual degree of vacuum Pr, the first tank 1′ having an initial internal pressure degree equal to the atmospheric pressure Patm, the second tank 2′ having an initial internal pressure degree lower than the atmospheric pressure Patm.

[0154] A second quantity Q2 of ingredients at a second initial temperature Tin2 is then loaded into the second tank 2′, said ingredients being intended to form said concrete, said ingredients comprising a second predetermined quantity of water.

[0155] Like the first initial temperature Tin1, the second initial temperature Tin2 also represents a mean temperature which depends on the temperature of the individual ingredients of the concrete.

[0156] Preferably, the second quantity Q2 and the second initial temperature Tin2 are substantially equal to the first quantity Q1 and to the first initial temperature Tin1, respectively.

[0157] The pressure inside the first tank 1′ must also be regulated so as to obtain a first transitory degree of vacuum Ptl in the first tank 1′.

[0158] The pressure is also regulated inside the hermetically sealed condensation chamber 4′ so as to obtain therein a basic degree of vacuum P2 greater than the first transitory degree of vacuum Ptl, i.e. such that the pressure in the condensation chamber 4′ is lower than the pressure in the first tank 1′.

[0159] After this, the first tank 1′ and the condensation chamber 4′ are operatively connected so as to substantially equalize the internal pressure in the first tank 1′ and in the condensation chamber 4′ to a resulting degree of vacuum P3 so as to cause at least partial evaporation “vap” of the water contained in the first tank 1′ towards the condensation chamber 4′, so as to lower the temperature of said ingredients in the first tank 1′.

[0160] The water evaporated from the first tank 1′ is then condensed in the condensation chamber 4′.

[0161] Subsequently, the first tank 1′ and the second tank 2′ are operatively connected so as to substantially equalize the internal pressure in the first tank 1 and in the second tank 2′ to a further residual degree of vacuum Pr', the second tank 2′ having an initial internal pressure degree equal to the atmospheric pressure Patm, the first tank 1′ having an initial internal pressure degree lower than the atmospheric pressure Patm.

[0162] According to one aspect, the equalization of the pressure between the first tank 1′ and the second tank 2′ takes place as a result of the effect of opening one or more equalization valves 12′. According to one aspect, the plant 100′ comprises connection ducts 15′ which can operatively connect each tank of the plurality of tanks 200′ so as to equalize the internal pressure inside the tanks.

[0163] At this point, it is possible to collect said ingredients from the first tank 1′ at a first output temperature Toutl lower than said first initial temperature Tin1.

[0164] According to one aspect, the condensation water is conveyed once more from the condensation chamber 4′ to the first tank 1′ so as to keep the quantity of water present inside the first tank substantially unvaried compared with the initial quantity. This is in order to comply with the relative proportion of water indicated by the concrete recipe and the ratio of water to cement indicated according to said recipe. Advantageously, the water evaporated from the first tank 1′ is restored to the mix in the form of cold water. Preferably, the condensation chamber 4′ and the first tank 1′ are operatively connected by means of a recycling pipe 10′ which can convey the condensate once more into the first tank 1′ containing the mixture of ingredients of the concrete.

[0165] According to a further advantageous aspect, the recycling pipe 10′ of any tank l′-3′ of the plurality of tanks 200′ comprises an upper opening 42′ which is located below a heat exchange portion 43′ inside the condensation chamber 4′. Advantageously, the recycling pipe 10′ can convey the evaporated water “vap” through the interconnection valve 11′ from the tank towards the heat exchange portion 43′ of the condenser 41′. In turn, as a result of its position above the upper opening 42′, the heat exchange portion 43′ can exclusively condense the evaporated water “vap” from said tank and conveyed by said recycling pipe 10′.

[0166] In addition, the upper opening 42′ is configured to receive the condensed water “con” exclusively from the heat exchange portion 43′ so as to

[0167] convey the water to the tank once more. This arrangement makes it possible to keep the quantity of evaporated water “vap” at the output from the tank and the quantity of condensed water “con” which is conveyed once more to said tank substantially equivalent.

[0168] According to one aspect, the heat exchange portion 43′ can be a tube bundle of the condenser 41′, said tube bundle having an exchange surface with dimensions such as to condense the quantity of evaporated water “vap” from a tank of the plurality of hermetically sealed tanks 200′. According to one aspect, the process according to the invention proceeds by loading into the first tank 1′ a third quantity Q3 of ingredients intended to form said concrete, said ingredients comprising a relevant third predetermined quantity of water at a third initial temperature Tin3.

[0169] It is then necessary to regulate the pressure inside the second tank 2′ so as to obtain a second transitory degree of vacuum Pt2 in the second tank 2′.

[0170] In addition, in analogy with the phases undergone by the first tank 1′, the pressure inside the condensation chamber 4′ is regulated to a further basic degree of vacuum P2′ greater than the second transitory degree of vacuum Pt2, i.e. such that the pressure in the condensation chamber 4′ is lowerthan the pressure in the second tank 2′.

[0171] After this, it is necessary to operatively connect the second tank 2′ and the condensation chamber 4′ so as to substantially equalize the internal pressure in the second tank 2′ and in the condensation chamber 4′ to a further resulting degree of vacuum P3′ so as to cause at least partial evaporation “vap” of the water contained in the second tank 2′ towards the condensation chamber 4′, so as to lower the temperature of said ingredients in the second tank 2′.

[0172] The water evaporated by the second tank 2′ is then condensed in the condensation chamber 4′.

[0173] Subsequently, the first tank 1′ and the second tank 2′ are operatively connected so as to substantially equalize the internal pressure in the first tank 1′ and in the second tank 2′ to a second further residual degree of vacuum Pr″, the first tank 1′ having an initial internal pressure degree equal to the atmospheric pressure Patm, the second tank 2′ having an initial internal pressure degree lower than the atmospheric pressure Patm.

[0174] Finally, said ingredients can be collected from the second tank 2′ at a second output temperature Tout2 lower than said second initial temperature Tin2, said second output temperature Tout2 being the mean temperature of the material collected from the tank 2′.

[0175] According to one aspect, the cyclical vacuum source 7′ comprises a vacuum tank 8′ which is operatively connected to each tank of the plurality of hermetically sealed tanks 200′ so as to accelerate the regulation of the internal pressure in each tank of the plurality of hermetically sealed tanks 200′.

[0176] According to one aspect, the plant 100′ and the method for cooling according to the present invention can be used to cool a mixture of water and sand in the absence of stones and in the absence of binding agents, such as, for example, cement.

[0177] According to a further advantageous aspect, the basic vacuum source 6′ comprises a vacuum tank 8′ which is operatively connected to the condensation chamber 4′ so as to accelerate the times required to regulate the basic degree of vacuum inside the condensation chamber 4′. According to preferred embodiments, each tank 1′-3′ of said plurality of hermetically sealed tanks 200′ comprises a mixer 9′ which is designed to mix the ingredients of the concrete inside the tank itself.

[0178] According to a further advantageous aspect, thermal insulation is provided for the condensation chamber 4 and/or for one or more of the tanks for cooling the concrete so as to reduce the absorption of heat from the outside, and thus reduce the energy consumption and the times required for the cooling process.

[0179] Preferably, at least one gap 16′ is provided, which can be interposed between an outer wall of a tank l′-3′ of the plurality of tanks 200′ and a mixer 9′ placed inside said tank, or interposed between the condenser 41′ and an outer wall of the condensation chamber 4′, said gap 16′ being able to be depressurized so as to thermally insulate said mixer 9′ or said condenser 41′.

[0180] Advantageously, the gap 16′ surrounds and encloses the condensation chamber 4′ or the cooling tanks so as to reduce the absorption of heat from the outside.

[0181] The invention thus solves the problem posed, and achieves numerous advantages, including:

[0182] the possibility of cooling a mixture of ingredients of concrete (both conventional concrete and RCC) to temperatures of 10° C. or less; recycling of the condensation water so as to substantially not alter the quantity of water provided in the mixture of concrete ingredients according to a predetermined recipe of the concrete;

[0183] use of a plurality of compact tanks for the concrete which comprise a smaller volume to be emptied, and thus a reduction of the plant costs;

[0184] interconnection logic between tanks designed to contain the mixture of concrete ingredients which makes it possible to always keep the cooling and pumping process in operation, with consequent elimination of dead times;

[0185] a cooling process which comprises an energy saving of more than 30% compared with the cited prior art;

[0186] the possibility of using a single condenser to condense the water evaporated from a plurality of tanks for the concrete;

[0187] use of the residual degree of vacuum inside the concrete ingredient tanks before discharging the cooled material;

[0188] a cooling process which is ready for production in a few minutes and allows the concrete to be cooled in less than an hour;

[0189] a cooling process which allows to cool the concrete in real time without being affected by the state of the plants upstream or downstream, and without requiring energy for the pre-cooling of the construction aggregates or for maintenance of the temperature,