Inflation system of a press for vulcanization of tires

Abstract

An inflation system (1) of a press for vulcanization of tires, comprising a supply circuit (6) of the inflation fluid, intended to be connected to a fluid supply network and to the bladder (7) of a tire vulcanization press. The supply circuit (6) includes a compressor (11), suitable for carrying out the circulation of the inflation fluid inside the supply circuit (6), and an electric heater (8), suitable for heating the inflation fluid up to at a set temperature value necessary to vulcanize the tire. The supply circuit (6) also includes a recirculation path (9) of the inflation fluid, which passes through said electric heater (8) and the bladder (7), suitable for feeding the bladder (7) of the press with the fluid maintained at a predetermined temperature and pressure during the vulcanization phase of a tire. The invention also relates to a method for inflating a press for vulcanization of tires.

Description

[0001] “INFLATION SYSTEM OF A PRESS FOR VULCANIZATION OF TIRES”

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention concerns an inflation system of a press for the vulcanization of tires.

[0004] BACKGROUND ART

[0005] During the vulcanization phase of a tire, the rubber of which it is composed increases its mechanical properties, making the tire itself compatible with the stresses to which it will be subjected during its use.

[0006] The rubber compounds with which a tire is made are generally complex mixtures of polymers with the addition of additives in variable quantities and nature, depending on needs.

[0007] Vulcanization (or cross-linking) represents the final stage of tire production, and it is thanks to it that the desired characteristics of the material can be obtained, such as mainly elasticity, abrasion resistance and load resistance.

[0008] Obviously, the final mechanical properties of the product are strongly dependent on its chemical composition, but also on the process parameters at which the reactions take place.

[0009] To obtain high productivity, it is useful to maintain the reaction temperature as high as possible during vulcanization, even if the operating conditions must be such as to keep the system below the temperatures at which thermal degradation of the material can occur.

[0010] Inside a special press, the tire, pushed by an internal pressure, comes into contact with a mold which gives it the specific shape of the desired tread.

[0011] In more detail, the mold vulcanizes the external part of the tire, while the internal part vulcanizes due to the high temperature of the fluid used to inflate the so-called drum (or bladder) located inside the press.

[0012] Normally, a mixture of steam and nitrogen is used to inflate the bladder; in particular, the steam has the function of obtaining the desired temperature inside the press bladder.

[0013] However, the use of steam is not desirable for the following reasons. Usually, the steam is produced through the use of fossil fuel boilers directly on the production site where the vulcanization presses are also installed, and this has a decidedly negative environmental impact, without considering the cost of the fuel which can be quite high.

[0014] Furthermore, the installation of boilers, pipes and various components necessary for the production of steam requires considerable economic and space resources within the production site.

[0015] It should be added that the production of steam with boilers requires training of personnel to operate in pressure vessels, with mandatory attendance of training courses; furthermore, this type of device requires certification and periodic checks by notified bodies.

[0016] Furthermore, during the vulcanization process, the steam inside the tire stratifies and forms condensation on the lower sidewall, which cannot be extracted during the process: this determines temperature differences between the upper sidewall and the lower sidewall of the tire, which can cause quality problems of the tire itself.

[0017] Last but not least, it should be noted that the bladder for inflating the tire, in contact with steam, deteriorates rather quickly due to a natural oxidation process.

[0018] AIMS OF THE INVENTION

[0019] The technical aim of the present invention is to improve the state of the art in the tire vulcanization sector.

[0020] Within the scope of this technical aim, it is an object of the present invention to develop an inflation system of a press for the vulcanization of tires which allows the previously complained drawbacks to be overcome, and, in particular, those relating to the use of steam for obtain the desired temperature inside the bladder of the vulcanization press.

[0021] Another object of the present invention is to create an inflation system of a press for the vulcanization of tires characterized by lower energy consumption compared to known systems.

[0022] A further object of the present invention is to make available an inflation system of a press for the vulcanization of tires that is simplified from a construction and control point of view.

[0023] Another object of the present invention is to devise an inflation system of a press for the vulcanization of tires characterized by lower installation and maintenance costs compared to known systems.

[0024] Another purpose of the present invention is to create an inflation system of a press for the vulcanization of tires with a lower environmental impact compared to existing systems.

[0025] This aim and these objects are all achieved by the inflation system of a press for the vulcanization of tires according to the attached claim 1.

[0026] The inflation system includes an inflation fluid supply circuit, intended to be connected to a fluid supply network and to the bladder of a tire vulcanization press. The supply circuit includes a compressor, suitable for carrying out the circulation of the inflation fluid within the supply circuit, and an electric heater suitable for heating the inflation fluid up to a set temperature value necessary to carry out vulcanization of the tire.

[0027] The supply circuit also includes, according to the present invention, a recirculation path for the inflation fluid, which passes through the electric heater and the bladder, suitable for feeding the press bladder with the fluid maintained at a predetermined temperature and at a predetermined pressure specifically during the vulcanization phase of a tire.

[0028] Thanks to this feature of the supply circuit, the press can carry out the tire vulcanization phase quickly and effectively, with minimal energy expenditure and with a simplified and eco-compatible construction solution.

[0029] In fact, the use of steam to obtain the desired temperature inside the press bladder is completely eliminated.

[0030] Furthermore, the use of nitrogen alone, instead of the nitrogen and steam mixture, allows important advantages to be obtained from the point of view of environmental impact and the quality of the product obtained.

[0031] The dependent claims refer to preferred and advantageous embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Further characteristics and advantages of the present invention will be more evident from the detailed description of a preferred, but not exclusive, embodiment of an inflation system of a press for the vulcanization of tires, illustrated by way of example, but not by way of limitation, in the attached tables, of drawings in which: figure 1 is an axonometric view of the inflation system according to the present invention; figure 2 is a top view of the inflation system; figure 3 is a front view of the inflation system; figure 4 is a left side view of the inflation system; figure 5 is a rear view of the inflation system; figure 6 is an axonometric view, partially sectioned, of the inflation system compressor; figure 7 is a cross section of the chamber which houses the compressor impeller; figure 8 is a front view of the chamber which houses the compressor impeller; figure 9 is a front view of the compressor impeller; figure 10 is a system diagram of the inflation system according to the invention; figure 11 represents the same system diagram as figure 10 with the fluid path highlighted in a first phase of the system's operation, in which the fluid is introduced and heated to the optimal temperature; figure 12 represents the same system diagram as figures 10, 11 with the path of the fluid highlighted in a subsequent phase, in which the fluid is sent into the press bladder at a controlled pressure; figure 13 represents the same system diagram as figures 10-12, with the path of the fluid highlighted in a further phase, in which the fluid is sent into the press bladder to inflate the tire to be vulcanized; figure 14 represents the same plant diagram as figures 10-13, with the path of the fluid highlighted in yet another phase, in which the fluid circulates between the press and the electric heater, to keep its temperature constant during vulcanization; figure 15 represents the same system diagram as figures 10-14, with the path of the fluid highlighted in the final phase of deflation of the vulcanized tire.

[0033] EMBODIMENTS OF THE INVENTION

[0034] With reference to the attached figures, the reference number 1 generally indicates an inflation system of a press for the vulcanization of tires according to the present invention.

[0035] The system 1 includes a platform 2, for supporting and resting on the ground.

[0036] The system 1 also includes a control panel 3, supported by the aforementioned platform 2.

[0037] The system 1 includes a control unit 4, to which all the components of system 1 are operationally connected and slaved.

[0038] The control unit 4 consists, preferably, of a programmable logic controller (PLC).

[0039] The control unit 4 is housed inside the control panel 3.

[0040] The control panel 3 also includes a user interface 5 (visible, in particular, in figure 5), for controlling and managing the operation of the system 1, via the control unit 4.

[0041] The system 1 includes an inflation fluid supply circuit, globally indicated with 6, intended to be connected to a fluid supply network and to the bladder 7 of a tire vulcanization press.

[0042] The supply circuit 6 includes an electric heater 8, suitable for heating the inflation fluid up to the temperature necessary to carry out vulcanization of the tire.

[0043] According to a specific and advantageous aspect of the invention, the supply circuit 6 includes a recirculation path 9 of the inflation fluid, which passes through the electric heater 8 and the bladder 7, suitable for feeding the bladder 7 of the press with the fluid kept at a pre-set temperature and at a pre-set pressure during the vulcanization phase of a tire.

[0044] As will be better clarified below, thanks to this feature, the press can carry out the tire vulcanization phase quickly and effectively, with minimal energy expenditure and with a simple and eco-compatible construction solution, which also guarantees a high product quality.

[0045] In greater detail, the supply circuit 6 includes an inlet branch 10 for the inflation fluid.

[0046] According to another aspect of the invention, the inflation fluid is nitrogen.

[0047] The inlet branch 10 can be connected to an inflation fluid supply network (not shown in the figures), i.e. in particular a nitrogen supply network, at a given pressure.

[0048] The supply circuit 6 also includes a compressor 11 for the inflation fluid.

[0049] The compressor 11 is designed to carry out the circulation of the inflation fluid within the supply circuit 6.

[0050] The compressor 11 is supported by the platform 2, and it is operationally connected and slaved to the control unit 4.

[0051] The supply circuit 6 also includes a delivery branch 12 and a return branch 13 for the inflation fluid, both associated with the compressor 11.

[0052] The inlet branch 10 of the inflation fluid intercepts the aforementioned return branch 13 immediately downstream of the suction port of the compressor 11.

[0053] The delivery branch 12 completely passes through the electric heater 8.

[0054] Furthermore, the delivery branch 12 communicates with the access opening 14 of the bladder 7 of the press.

[0055] The return branch 13 communicates, instead, with the exit opening 15 of the same bladder 7.

[0056] The electric heater 8 is operationally connected and slaved to the control unit 4, and it is supported by the platform 2.

[0057] The electric heater 8 includes, internally, electrical resistors arranged so as to heat the inflation fluid which circulates inside it.

[0058] The electric heater 8 includes, more specifically, an inlet mouth 16 and an outlet mouth 17 for the inflation fluid, both communicating with the delivery branch 12.

[0059] The supply circuit 6 includes, in addition, a first bypass branch 18, which connects the delivery branch 12 to the return branch 13, so as to completely and selectively exclude the bladder 7.

[0060] The supply circuit 6 also includes a second bypass branch 19, and a third bypass branch 20. The second bypass branch 19 and the third bypass branch 20 are arranged in parallel with respect to the delivery branch 12, in particular at a central section 21 thereof.

[0061] The supply circuit 6 also includes a discharge branch 22 of the inflation fluid, which communicates with the return branch 13.

[0062] A first solenoid valve 23 is installed along the first bypass branch 18; the first solenoid valve 23 is operationally connected, and slaved, to the control unit 4.

[0063] Likewise, a second solenoid valve 24 is installed along the second bypass branch 19, while a third solenoid valve 25 is installed on the third bypass branch 20.

[0064] The second solenoid valve 24 and the third solenoid valve 25 are both operationally connected, and slaved, to the control unit 4.

[0065] Also provided, in system 1, are a fourth solenoid valve 26 and a fifth solenoid valve 27, installed, respectively, along the delivery branch 12 and the return branch 13.

[0066] The fourth solenoid valve 26 and the fifth solenoid valve 27 are also operationally connected, and slaved, to the control unit 4.

[0067] A sixth solenoid valve 28 and a seventh solenoid valve 29 are installed along the discharge branch 22; the sixth solenoid valve 28 and the seventh solenoid valve 29 are also operationally connected, and slaved, to the control unit 4.

[0068] According to another aspect of the invention, the supply circuit 6 includes a first temperature sensor 30, associated with the electric heater 8.

[0069] The first temperature sensor 30 is operationally connected to the control unit 4; it detects the temperature of the inflation fluid inside the electric heater 8.

[0070] The supply circuit 6 also includes a second temperature sensor 31.

[0071] The second temperature sensor 31 (operationally connected to the control unit 4) detects the temperature of the inflation fluid along the delivery branch 12, near - and immediately downstream - of the electric heater 8.

[0072] The supply circuit 6 also includes a third temperature sensor 32.

[0073] The third temperature sensor 32 (operationally connected to the control unit 4) detects the temperature of the inflation fluid inside the bladder 7 of the press.

[0074] Figure 6 shows the compressor 11 in a partially sectional axonometric view. The compressor 11 is associated with a respective electric motor 33, operationally connected and slaved to the control unit 4 (and controlled, for example, by an inverter).

[0075] As visible in the aforementioned figure 6, the compressor 11 includes an impeller 34, connected to the shaft of the electric motor 33.

[0076] The impeller 34 has a substantially discoidal shape (figures 7 and 9).

[0077] The impeller 34 is housed inside a chamber 35 (figure 7), defined between opposing walls 36 of the compressor 11, which includes a central portion having a first width (in the axial direction) and a peripheral portion having a second width (also in the axial direction) greater than said first width.

[0078] According to a further aspect of the invention, the impeller 34 includes a plurality of blades 37, made in relief on at least one of the surfaces of the impeller 34 itself.

[0079] The blades 37 are distributed in two series of which a first series is closer to the center, and a second series is more peripheral.

[0080] The blades 37 have a substantially radially curved conformation (according to circumferential arcs, and with lengths different from each other, in particular blades 37 of longer length alternating with blades 37 of shorter length).

[0081] The chamber 35, in which the impeller 34 is housed, also results in an outlet duct 37a for the inflation fluid (see in particular figure 8), oriented substantially tangential to the axis of rotation of the impeller 34 itself.

[0082] The special geometry and conformation of the impeller 34 of the compressor 11, and also of the outlet duct 37a, is optimized for the particular pressure and temperature range at which the inflation fluid operates.

[0083] As will be clearer from the subsequent description of the operation of the system 1, the supply circuit 6 defines a plurality of paths 9, 38, 39, 40, 41 for the circulation of the inflation fluid in relation to the different phases of the operation of the system 1 itself.

[0084] More in detail, and in relation to the state of opening or closing of the solenoid valves 23-29, selectively carried out by the control unit 4, according to the invention, the supply circuit 6 includes and defines: - a loading and heating path 38 of the inflation fluid;

[0085] - a shaping path 39 of the press bladder 7;

[0086] - an inflation path 40 of the press bladder 7;

[0087] - a recirculation path 9 of the inflation fluid between the bladder 7 and the electric heater 8;

[0088] - a deflation path 41 of the vulcanized tire.

[0089] As shown in figure 11, the loading and heating path 38 of the inflating fluid includes the inlet branch 10, the delivery branch 12 and the return branch 13, in which the latter are placed in communication via the first bypass branch 18, so as to exclude bladder 7.

[0090] Therefore, in this path the inflation fluid enters from the inlet branch 10 and is circulated, by the compressor 11, through the electric heater 8.

[0091] As shown in figure 12, the shaping path 39 includes the already described loading and heating path 38, to which is added the entire delivery branch 12 with the exception of its central section 21 (in which the fourth solenoid valve 26 is provided), since in this case the fluid passes through the second bypass branch 19.

[0092] The shaping path 39 therefore allows the inflation fluid to be sent inside the bladder 7, adequately heated and at a controlled pressure (necessary to obtain the shaping of the bladder 7, phase which precedes the final closing of the press).

[0093] As shown in figure 13, the inflation path 40 includes the already described loading and heating path 38, to which the entire delivery branch 12 is added with the exception of its central section 21, since in this case the fluid passes through the third bypass branch 20.

[0094] The inflation path 40 allows the fluid to be sent with a sufficient flow rate to obtain, in fact, the complete inflation of the bladder 7, to the desired and pre-set pressure.

[0095] As shown in figure 14, the aforementioned recirculation path 9 includes the delivery branch 12 and the return branch 13, including, naturally, the electric heater 8 and the bladder 7.

[0096] In this path, which is activated during the actual vulcanization phase, the inflation fluid is kept in circulation between the bladder 7 and the electric heater 8 with an appropriately controlled and calibrated flow rate, so as to maintain the desired temperature and pressure, for the time necessary for the process to be carried out correctly.

[0097] Finally, as shown in figure 15, the deflation path 41 includes the return branch 13 (in particular its section immediately adjacent to the bladder 7) and the discharge branch 22.

[0098] Furthermore, the deflation path 41 includes the delivery branch 12 and the return branch 13, placed in communication via the first bypass branch 18.

[0099] This path therefore allows the vulcanized tire to be deflated, while the inflation fluid is kept at the correct temperature thanks to its circulation inside the electric heater 8.

[0100] The operation of the inflation system 1 according to the present invention is, in light of what has been described, as follows.

[0101] In an initial phase (figure 11), the first solenoid valve 23 is opened, while the other solenoid valves are closed and the fluid, coming from the inlet branch 10, circulates in the loading and heating path 38.

[0102] The electric heater 8, therefore, increases the temperature of the inflation fluid up to a set value (and controlled via the second temperature sensor 31), and the pressure of the latter reaches that of the supply network.

[0103] Subsequently (figure 12), the shaping path 39 is activated by opening the second solenoid valve 24.

[0104] The inflation fluid, then, through the delivery branch 12, is sent, with controlled pressure, inside the bladder 7, so as to obtain the first inflation phase of the bladder 7 itself.

[0105] In this phase, the inflation fluid continues to circulate in the loading and heating path 38, in particular so as to maintain its temperature and pressure at the desired values.

[0106] With reference, now, to figure 13, the inflation path 40 is activated, by closing the second solenoid valve 24 and opening the third solenoid valve 25.

[0107] The inflation fluid is then sent into the bladder 7 with a greater flow rate, so as to reach the pressure set for inflating the tire to be vulcanized.

[0108] Once the aforementioned pressure has been reached (figure 14), the recirculation path 9 is activated, by closing the first solenoid valve 23, and by opening the fourth solenoid valve 26 and the fifth solenoid valve 27.

[0109] The inlet branch 10 is also closed.

[0110] In this condition, the temperature of the inflation fluid is maintained through the readings of the second temperature sensor 31, while the internal temperature of the tire, detected by the third temperature sensor 32, is reached by acting on the speed of the motor 33 of the compressor 11.

[0111] This internal temperature of the tire is then maintained by modulating the speed of the motor 33 of the compressor 11, managed by the control unit 4.

[0112] Once the tire vulcanization phase is completed, the deflation path 41 is activated (figure 15), by closing the fourth solenoid valve 26 and the fifth solenoid valve 27, and by opening the first solenoid valve 23, the sixth solenoid valve 28 and the seventh solenoid valve 29.

[0113] In this phase, the vulcanized tire deflates, while the temperature of the inflation fluid is maintained through circulation in the closed compressor 11 - heater 8 path (with the inlet branch 10 closed), in order to then start another inflation cycle.

[0114] It is also an object of the present invention a method for inflating a press for the vulcanization of tires, carried out with the system 1 previously described.

[0115] The method according to the invention includes the steps of:

[0116] - loading and heating the inflation fluid in the supply circuit 6; shaping the bladder 7 of the press; inflating the bladder 7 of the press; recirculating the inflation fluid, at a controlled temperature, within a closed path including the compressor 11, the electric heater 8 and the bladder 7 of the press; deflating the bladder 7 of the press.

[0117] In particular, according to the present invention, the recirculation phase of the inflation fluid is carried out by modulating the rotation speed of the motor 33 of the compressor 11 in relation to the internal temperature value of the bladder 7, during the tire vulcanization phase, detected by the third temperature sensor 32.

[0118] It has thus been seen how the invention achieves the proposed purposes.

[0119] The system 1 according to the present invention, thanks to the complete elimination of steam as an inflation fluid, entirely replaced by electrically heated nitrogen, makes it possible to obtain a non-negligible energy saving compared to existing solutions, mainly thanks to the fact that the necessary temperature of the fluid is obtained, in fact, with the sole electric heating of the nitrogen.

[0120] Furthermore, the system 1 according to the invention, again thanks to the elimination of steam, and therefore of the boilers and plants to produce it, has a significantly lower environmental impact compared to known systems.

[0121] It should be added that, thanks to the characteristics of system 1 according to the present invention, and therefore thanks to the elimination of steam production systems, maintenance times and costs are significantly reduced.

[0122] The need to train personnel to operate in the pressure vessels of steam production plants is also eliminated.

[0123] Last but not least, the quality of the vulcanized products is increased, and the life of the press components (in particular the bladder) is extended.

[0124] All these important results are obtained with a solution which is constructionally simple, practical and easy to use, and with a relatively low cost.

[0125] The invention thus conceived is susceptible to numerous modifications and variations, all falling within the scope of the inventive concept.

[0126] Furthermore, all details can be replaced by other technically equivalent elements.

[0127] In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to needs, without thereby departing from the scope of protection of the following claims.

Claims

CLAIMS1. Inflation system (1) of a press for the vulcanization of tires, comprising a supply circuit (6) of the inflation fluid, intended to be connected to a fluid supply network and to the bladder (7) of a press for the vulcanization of tires, in which said supply circuit (6) includes a compressor (11), capable of carrying out the circulation of the inflation fluid within said supply circuit (6), and an electric heater (8), suitable for heating the inflation fluid up to a set temperature value necessary to carry out the vulcanization of the tire, characterized in that said supply circuit (6) includes a recirculation path (9) of the inflation fluid, which passes through said heater electric (8) and the bladder (7), designed to feed the bladder (7) of the press with the fluid maintained at a pre-set temperature and at a pre-set pressure during the vulcanization phase of a tire.

2. System (1) according to claim 1, wherein said supply circuit (6) includes a loading and heating path (38) of the inflation fluid, in which the inflation fluid enters said supply circuit (6) from an inlet branch (10) and circulates through said electric heater (8).

3. System (1) according to claim 2, in which said feeding circuit (6) includes a shaping path (39) of the bladder (7) of the press, suitable for sending, inside the bladder (7), the inflation fluid, adequately heated and at a controlled pressure.

4. System (1) according to claim 3, in which said supply circuit (6) includes an inflation path (40) of the bladder (7) of the press, suitable for sending the fluid inside the bladder (7) for obtain its complete inflation, at the preset temperature and pressure.

5. System (1) according to claim 4, comprising a deflation path (41) of the vulcanized tire, suitable for deflating the vulcanized tire, and for maintaining the inflation fluid at the correct temperature in order to proceed with a subsequent vulcanization cycle.

6. System (1) according to one of the previous claims, in which said loading and heating path (38), and / or said shaping path (39), and / or said inflation path (40), and / or said recirculation path (9), and / or said deflation path (41) are activatedby opening and / or closing a plurality of solenoid valves (23)-(29) of said supply circuit (6), operationally connected and slaved to a control unit (4) of the system (1).

7. System (1) according to one of the previous claims, in which said supply circuit (6) includes a delivery branch (12) and a return branch (13), both associated with said compressor (11), in which said delivery branch (12) completely passes through said electric heater (8).

8. System (1) according to claim 7, in which said supply circuit (6) includes a first bypass branch (18), which connects said delivery branch (12) to said return branch (13), so to completely exclude the bladder (7), in which said first bypass branch (18) is included in said loading and heating path (38).

9. System (1) according to claim 8, wherein said supply circuit (6) includes a second bypass branch (19) arranged in parallel with respect to said delivery branch (12), wherein said second bypass branch (19) is included in said shaping path (39).

10. System (1) according to claim 8 or 9, in which said supply circuit (6) includes a third bypass branch (20) arranged in parallel with respect to said delivery branch (12), in which said third bypass branch bypass (20) is included in said inflation path (40).

11. System (1) according to one of claims 7-10, in which said supply circuit (6) includes a discharge branch (22) of the inflation fluid, communicating with said return branch (13).

12. System (1) according to one of claims 7-11, wherein said first bypass branch (18), said second bypass branch (19) and said third bypass branch (20) are selectively regulated by means, respectively, of a first solenoid valve (23), a second solenoid valve (24) and a third solenoid valve (25).

13. System (1) according to one of claims 7-12, in which a fourth solenoid valve (26) and a fifth solenoid valve (27) are installed, respectively, along said delivery branch (12) and along said return branch (13).

14. System (1) according to claim 11, in which a sixth solenoid valve (28) and aseventh solenoid valve (29) are installed along said discharge branch (22).

15. System (1) according to one of the previous claims, in which said supply circuit (6) comprises a first temperature sensor (30), associated with said electric heater (8), a second temperature sensor (31), suitable to detect the temperature of the inflation fluid along said delivery branch (12) in proximity to said electric heater (8), and a third temperature sensor (32), suitable for detecting the temperature of the inflation fluid inside the bladder (7) of the press.

16. System (1) according to one of the previous claims, in which said compressor (11) includes an impeller (34) having substantially discoidal shape, comprising a plurality of blades (37), made in relief on at least one of the surfaces of said impeller (34), having a substantially curved radial conformation.

17. System (1) according to claim 16, in which said impeller (34) comprises blades (37) with different lengths, in particular blades (37) of longer length alternating with blades (37) of shorter length.

18. System (1) according to claim 16 or 17, in which said impeller (34) is housed inside a chamber (35) defined between opposing walls (36) of said compressor (11), which includes a central portion having a first width in the axial direction, and a peripheral portion having a second width, also in the axial direction, greater than said first width.

19. System (1) according to claim 18, in which said chamber (35) results in an outlet duct (37a) of the inflation fluid, oriented substantially tangentially with respect to the axis of rotation of said impeller (34).

20. Method for inflating a press for the vulcanization of tires, implemented with the system (1) according to one of claims 1-19, characterized in that it includes the steps of: loading and heating the inflation fluid in said supply circuit (6); shaping the bladder (7) of the press; inflating the bladder (7) of the press; carrying out the recirculation of the inflation fluid, at a controlled temperature,within a closed path including said compressor (11), said heater (8) and the bladder (7) of the press; deflating the bladder (7) of the press.

21. Method according to claim 20, in which said step of carrying out the recirculation of the inflation fluid is carried out by modulating the rotation speed of the motor (33) of said compressor (11) in relation to the internal temperature value of the bladder (7), during the tire vulcanization phase, detected by the third temperature sensor (32).

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