The innovation finds particular even if not exclusive application in the field of fluids recovering (oil water, etc.) of heat exchange circuits in machines of the industrial technique as for example machines for the ice-cream production or machines for the moulding of plastics material (dies cooling), etc.

Background Art It is known that in prior art there are many types of machines which use, fluid cooled circuits, in particular water or oil.

The fluids utilised for the cooling generally come out at a temperature higher than the average environmental one E.g.

35-40"C so that their effective cooling is important for a suitable recalculation obtained with minimum dimensions and suitable efficiency.

In prior art, exist already apparatuses of such type, which are built substantially as a cooling tower involving the recalculation of the operating fluid come out from the main machine subjecting it to a heat exchange by a passage through a forced air-jet, also by using the evaporative system.

In this way the temperature of said fluid is lowered to a not very high level and generally a little higher than the environment air temperature. For example if the environment air is at 20°C

the temperature of the fluid can be lowered from 35-40°C to a value not lower than 20"C. or at the maximum in its inside or little less (by using the evaporative system).

This fact involves the drawback that the heat exchange efficacy inside of the main machine (E.g. machine from ice-cream machine of pressure-injection for plastics materials, etc.) is rather reduced.

In the cooling towers and in the air water exchangers of the evaporative type in general, the temperature at which it is possible to recover the water cannot get lower than the temperature of the damp bulb of the utilised air.

Normally, in the summer months, it is calculated that the temperature of the damp bulb is about 24-25"C so that the cooling is notoriously limited.

In the water-air exchangers of the non-evaporative type (for example finned dry exchangers), the temperature by which it is possible to recover the water cannot get lower than the temperature of the dry bulb of the utilised air and therefore the lowering of temperature is more limited.

The aim of this invention is to avoid the above-mentioned drawbacks by creating an apparatus that is able to supply a more cooling efficacy to the said operating fluids (heat exchange) in said main operative machines.

This and other aims are reached as claimed by means of an apparatus that includes cooling tower means by air-jets, for the cooling of operating fluids circulating by heat exchange in

main operative machines, of the type involving: - at least one inlet of said operating fluid heated by the heat exchange in said main machine and - at least one coupling for the re-inlet of said operating fluid, suitably cooled by means of said cooling tower means, in the recalculation system of said main machine, characterised in that in it is included at least one freezing circuit with evaporators means and condenser means, in which: said condenser means are put at the beginning of said cooling tower means for exchanging heat with the said air-low, before it covers said cooling tower means; said evaporators means are put at the end of said cooling tower means for exchanging heat with said operating fluid for its further cooling.

In this way it is obtained a considerable higher yield being possible to bring the operating temperature also to extremely low and lower than the environment temperature values.

These and other advantages will appear from the following description of two preferred embodiments, with the aid of the included drawings whose details are not to be considered as limitative but only given as an example.

Figure 1 is a schematic view of a simplified system according to the invention, in this specific case with a single condenser radiator for cooling operating water by a not-evaporative external system.

Figure 2 is a view of a solution with double radiator of the

condenser and use of evaporative external system.

Referring to the figures it is possible to notice that with 1, 2 and 3 is shown the flow of the cooling air, while is not shown the fan in compression or suction that determines such flow being this latter of prior art.

With 11 is shown the equipment's container.

With 4 and 6 are respectively shown the couplings for the operating water inlet and outlet (or other fluid) from the main machine (Eg. Machine for ice-cream not shown).

With 8 is shown the cooling tower of prior art, for the cooling of the operating fluid 4-6.

With 10 is shown the freezing circuit inserted in the system, which innovatively places the condenser (7) or more condensers (7, 19), as inlet of the airflow, at the beginning of the cooling tower, and the evaporator (9) at the end of the cooling tower to cool further the operating fluid, by means of the connection 5 before of the discharging and recirculation in the main operating machine (6).

A work example results from the parameters indicated in the figure on the respective temperatures where: When the air gets in from the outside 1 the temperature is the environmental one Ta.

The air is heated at Tm>Ta getting through the condenser means (7) drying.

In the meantime when it gets in 4 the operating fluid has a temperature Te>Tm and consequently in the tower 8 this operating fluid is cooled at a certain value, while the air exits from the opposite side at a temperature TF>Tm.

The efficiency of the heat exchanges in 7 and 8 may be improved by using an external evaporative system Eg. by water spraying (15,16). The tower 8 can also use an evaporative system.

Before being discharged the operating fluid is made pass through the evaporator 9 of the freezing circuit, thus obtaining its further cooling at a temperature Tu<Te.

The outlet temperature Tu in this way can reach values also extremely low with respect to the ambient temperature and get to about 0" C.

In the solution of Fig.2 is indicated the rain-like or spraying evaporative system for improving the exchange by, an intermediate collector (13) that collects the discharge of the water from rain or spray both from the condenser (19-17) and from the cooling tower (8,12), to then be made recirculate by a pump (14) respectively above the condenser (16) and over the tower (15).

The space 18 between the two condensers will make possible that in the condenser group there is more heat exchange efficiency as in the second condenser (19) is utilized the evaporation of the water from external wetting (16).