EP3683530B1

EP3683530B1 - Air cooled heat exchanger

Info

Publication number: EP3683530B1
Application number: EP19020036.0A
Authority: EP
Inventors: Thierry Bultot; Trung LUU; Pascal Malpoix
Original assignee: Esindus SAU
Current assignee: Esindus SAU
Priority date: 2019-01-18
Filing date: 2019-01-18
Publication date: 2023-08-30
Anticipated expiration: 2039-01-18
Also published as: EP3683530A1; EP3683530C0

Description

Abstract of the disclosure

The invention relates to an air-cooled heat exchanger comprising heat exchanger units associated to a fan driven into rotation by a driving motor with interposition or not of a gearing box. At least the driving motor is suspended by a suspension means (40) connected to a collector pipe and/or intermediate (advantageously walkway) bridging element of a heat exchanger unit, whereby at least a part of the suspension means is mounted movable with respect to the said collector pipe and/or intermediate (advantageously walkway) bridging element, whereby at least the driving motor is movably mounted with respect to the bearing element.

The state of the art

Air cooled heat exchangers (ACHE) are used for years for cooling or condensing a liquid medium or vapour, such as water or water vapour, by transferring calories to air.
Such exchangers comprise a structure bearing one or more tube bundles, a fan driven into rotation by a drive assembly, and a plenum for directing the air flow form or to the fan. The fan can be for generating an induced air draft through the tube bundle (the fan being located above the tube bundle) or a forced air draft through the tube bundle (the fan being located below the tube bundle).
It has been proposed in EP3201550 an ACHE installation comprising central support pillars for bearing the tube bundles, but also the fans and their motors. The pillars have then to be over-dimensioned, as having to bear the weight of the tube bundles extending between distributor pipes and collector pipes, the motor, the fans, and supporting elements, as well as to take over all possible stresses due to the fans and motors. In such installation it is quite difficult to carry out maintenance work to the motor or gearing.
In such an installation the motor and its gearing box are mounted above the fan, meaning that the motor and gearing box will be submitted to weather conditions, like the heat of the sun, rain, dust storm, hail, etc... as well as problem due to the induced air draft by means exposed to hot air due to heat exchange, with possible dust. The gearing will thus be heated by the sun and/or heated air, meaning that the oil will often have to be replaced and/or gearing box will have to be oversized. Moreover, in case of thunder, the motors are often the place where the flashes strike.
The construction of such installation requires heavy lifting systems, meaning a higher risk of accidents, when lifting large heavy pieces, accidents having high damage consequences, for example on the structure.
Other problems arising with existing air-cooled heat exchangers are that the fan motor and/or gearbox is/are not the most efficiently cooled, due to the air flow generated tending to not to contact the gearbox and/or motor for cooling it, and/or that the gearbox and/or motor of the fan generates a perturbation for the air flow having to pass through the heat exchanger.
The invention aims at least to solve one or another of said problems.
The invention relates to an air-cooled heat exchanger assembly (1) of the type disclosed in US 3707185 A or in GB 958481 A and comprising at least one heat exchanger unit (10) for cooling and condensing at least partly a first fluid medium (F1) flowing in at least one passage of the heat exchanger unit (10) having at least an inner face contacting the said first fluid medium and at least one outer face not contacting said first fluid medium, by means of an air flow (F2) contacting at least one outer face of the heat exchanger unit (10), whereby the said first fluid medium (F1) and said air flow (F2) are not in direct contact together, said air-cooled heat exchanger assembly (1) comprising at least:

A heat exchanger unit (10). In US 3707185 A the heat exchanger unit comprises: (a1) a first heat exchanger element (11) extending between a first upper substantially horizontal distributor pipe (11a) for distributing the first fluid medium into said first heat exchanger element (11), and a first lower substantially horizontal collector pipe (11b) for collecting the at least partly condensed first fluid in said first heat exchanger element (11), and (a2) a second heat exchanger element (12) extending between a second upper substantially horizontal distributor pipe (12a) for distributing the first fluid medium into said second heat exchanger element (12), and a second lower substantially horizontal collector pipe (12b) for collecting the at least partly condensed first fluid in said second heat exchanger element (12), said second lower substantially horizontal collector pipe (12b) being advantageously in fluid connection with the said first substantially horizontal collector pipe (11b), whereby the first substantially horizontal distributor pipe (11a) is distant from the second substantially horizontal distributor pipe (12a) by a horizontal distance which is greater than the horizontal distance separating the first substantially horizontal collector pipe (11b) and the second substantially horizontal collector pipe (12b), and whereby the said first and second substantially horizontal distributor pipes (11a,12a) are forming supporting means for a fan assembly (20). In GB 958481 A , the heat exchanger unit comprises: (b1) a first heat exchanger element (13) extending between a first upper substantially horizontal distributor pipe (13a) for distributing the first fluid medium into said first heat exchanger element (13), and a first lower substantially horizontal collector pipe (13b) for collecting the at least partly condensed first fluid in said first heat exchanger element (13), and (b2) a second heat exchanger element (14) extending between a second upper substantially horizontal distributor pipe (14a), which is advantageously the first upper substantially horizontal distributor pipe (13a), for distributing the first fluid medium into said second heat exchanger element (14), and a second lower substantially horizontal collector pipe (14b) for collecting the at least partly condensed first fluid in said second heat exchanger element (14), whereby the first substantially horizontal collector pipe (13b) and the second substantially horizontal collector pipe (14b) are distant from each other; whereby said distant first and second distant substantially horizontal collector pipes (13b,14b) of the heat exchanger unit are associated to a supporting means for a fan assembly (20);
A fan assembly (20) comprising (a) a fan (21) and (b) a fan support (22) adapted to be attached to the said supporting means (11a,12a ) of the heat exchanger unit (10), possibly with interposition of an intermediate supporting piece, said fan assembly (20) comprising at least a bearing system (23) for co-operating with the fan (21);
A driving system (30) for driving into rotation the fan (21), said driving system (30) comprising at least a driving motor (31), and a driving shaft (33) adapted to co-operate with the fan (21), whereby the driving motor (31) is adapted for driving into rotation the driving shaft (33) and the fan (21) directly, or via an intermediate piece, like a gearing box (32).

GB 968430 A is disclosing a A-shaped heat exchanger provided with pillars or uprights for supporting the fan assembly.
US 3185213 A is disclosing in Figure 5 a V-shaped unit with a fan assembly attached to uprights via a supporting element.

BRIEF DESCRIPTION OF THE INVENTION

The invention relates to an air cooled heat exchanger assembly (1) as disclosed in the preamble of claim 1, said assembly being characterized in that:
at least the driving motor (31) is suspended by a suspension means (40) connected to at least one bearing element selected from the group consisting of the first substantially horizontal collector pipe (11b,13b), the second substantially horizontal collector pipe (12b,14b), and a bridging element (41) forming a connection between the said first substantially horizontal collector pipe (11b,13b) and the second substantially horizontal collector pipe (12b,14b), so that at least the driving motor (31) extends below the average vertical level (L1) of the first and second substantially horizontal collector pipes (11b,13b;12b,14b) (preferably below the levels of said first and second collector pipes), whereby at least a part of the suspension means (40) is mounted movable with respect to the bearing element (11b,13b;12b,14b;41), whereby at least the driving motor (31) is movably mounted with respect to the bearing element (11b,13b;12b,14b;41). In case of bridging element (41), the said bridging element is advantageously a walkway bridging element or a partly walkway bridging element.
With such an air-cooled heat exchanger assembly, the building and maintenance works are facilitated. Moreover, as the motor is suspended the one or the two collector pipes and/or bridging element (41) or a bridging element connecting said collector pipes or extending between said collector pipes, the motor acts as means stabilising the heat exchanger unit, the centre of gravity thereof being lowered. When building such heat exchanger, lighter devices for lifting in place the different parts of the heat exchanger can be used, whereby preventing some accidents or some damages during the building.
Advantageously, the at least a part of the suspension means (40) movable with respect to the bearing element (11b,13b;12b,14b;41) is at least vertically movable with respect the bearing element (11b,13b;12b,14b;41) between a first position in which the said part of the suspension means (40) is adjacent to the bearing element (11b,13b;12b,14b;41), and a second position in which the said part of the suspension means (40) is downwards distant from the bearing element (11b,13b;12b,14b;41). For example, the said part of the suspension means (40) is lowered up to the ground level, whereby enabling the maintenance works of the motor or its replacement.
Preferably, the intermediate piece is a gearing box (32) which is suspended by a suspension means (40bis) connected to a bearing element selected from the group consisting of the first substantially horizontal collector pipe (11b,13b), the second substantially horizontal collector pipe (12b,14b), and a bridging element (41) forming a connection between the said first substantially horizontal collector pipe (11b,13b) and the second substantially horizontal collector pipe (12b,14b), so that the gearing box (32) extends below the average vertical level (L1) of the first and second substantially horizontal collector pipes (11b,13b;12b,14b) (preferably below the level of the first and second horizontal collector pipes), whereby at least a part of the suspension means (40bis) is mounted movable with respect to the bearing element (11b,13b;12b,14b;41), whereby at least the gearing box (32) is movably mounted with respect to the bearing element (11b,13b;12b,14b;41). For example, the said part of the suspension means (40bis) is lowered up to the ground level, whereby enabling the maintenance works of the gearing box or its replacement.
According to advantageous embodiments, the heat exchanger assembly of the invention has one or more of the following characteristics or details:

^∗ the at least part of the suspension means (40,40bis) movable with respect to the bearing element (11b,13b;12b,14b;41) is associated to the driving motor (31) and the gearing box (32) or in which the at least part of the suspension means (40) for the driving motor (31) movable with respect the bearing element (11b,13b;12b,14b;41) is distinct form the at least part of the suspension element (40bis) for the gearing box (32) movable with respect to bearing element (11b,13b;12b,14b;41). Two distinct suspension means are used, whereby enabling separate maintenance or replacement works at ground level when required. In such an embodiment the connection of the motor to the gearing box is advantageously mobile so as to separate the motor from the gearing box. The movement of one suspension means is advantageously connecting automatically the driving system connecting the motor to the gearing box. In a possible embodiment the driving motor is mounted on a suspension means enabling horizontal movement of the driving motor suspension means with respect to the one or more collector pipes, so as to separate the driving motor from the gearing box, before moving vertically the driving motor suspension means or the gearing box suspension means.
^∗ The air cooled heat exchanger comprises a guiding piece (50) attached to a bridging element (41) connecting the said first substantially horizontal collector pipe (11b,13b) to the second substantially horizontal collector pipe (12b,14b), whereby said guiding piece (50) has a central open passage (52) for enabling the passage of the driving shaft (33), in which said guiding piece is advantageously associated to a bearing (51) or in which said guiding piece (50) or said bridging element (41) is advantageously provided with an attachment means (54) for a bearing (55) associated to the driving shaft (33). The driving shaft is so also suspended to the heat exchanger unit. This embodiment facilitates also the building and the transport of the air exchanger as a kit to be mounted, as quickly as possible on site.
^∗ the fan support (22) is adapted to be mounted between the first upper substantially horizontal distributor pipe (11a) and the second upper substantially horizontal distributor pipe (12a), the said fan support (22) comprising a connector (24) mounted rotatable on said fan support (22), said connector (24) comprising a hollow (25) with at least a downwards opening (26) for receiving the upper end (33U) of the driving shaft (33).
^∗ the hollow (25) of the said connector (24) and a portion of the driving shaft (33) adjacent to the said upper free end (33U) are adapted for enabling vertical relative displacement of the said upper free end (33U) of the driving shaft (33) within the said hollow (25) of the connector (24), while ensuring that the driving of the driving shaft (33) ensures the driving of the connector (24).
^∗ the hollow (25) of the connector (24) and a portion of the driving shaft (33) adjacent to the upper free end (33U) thereof are associated with interposition of a gliding means (27).
^∗ the connector (24) comprises an upper end (24U) adapted for mounting in a removable way the fan (21) or part thereof. This is quite advantageous for the mounting operations, as well as the transporting operations.
^∗ the fan assembly (20) comprises a substantially ring guiding element (28) in which the fan (21) is adapted to extend at least partly within the said ring guiding element (28), whereby the said substantially ring guiding element (28) is advantageously associated to a ring supporting means (29) for attaching it on the supporting means (11a, 12a;13b,14b), preferably in a removable way.
^∗ the fan support (22) comprises a bridging element adapted to be removably attached to the ring supporting means (29) or adapted to have ends (22a,22b) for resting on the supporting means (11a,12a;13b,14b), said ends (22a,22b) being then advantageously covered by a portion of the ring supporting means (29).
^∗ the bearing element (11b,13b;12b,14b;41) is provided with a mechanical system (42) for facilitating and/or guiding the relative movement of at least the driving motor (31) and part of the suspension means (40) with respect to said bearing element (11b,13b;12b,14b;41).
^∗ the motor (31) is a permanent magnet motor.
^∗ combinations thereof.

The invention relates also to a method of building or maintaining an air-cooled heat exchanger comprising a structure (S) supporting and/or suspending at least one air cooled heat exchanger assembly (1) according to the invention (as disclosed here above), said method comprising at least one of the following steps:

suspending at least the driving motor (31) by a suspension means (40) connected to a bearing element selected from the group consisting of the first substantially horizontal collector pipe (11b,13b), the second substantially horizontal collector pipe (12b,14b), and a bridging element (41) forming a connection between the said first substantially horizontal collector pipe (11b,13b) and the second substantially horizontal collector pipe (12b,14b), so that the driving motor (31) extends below the average level (L1) of the first and second substantially horizontal collector pipes (11b,13b,12b,14b), whereby at least a part of the suspension means (40) is mounted movable with respect to the bearing element (11b,13b;12b,14b;41), whereby at least the driving motor (31) is movably mounted with respect to the bearing element (11b,13b;12b,14b;41);
moving the suspension means (40) in order to move relatively at least the driving motor (31) from the bearing means (11b,13b;12b,14b;41) to a downwards position facilitating at least the maintenance of the driving motor (31) and/or the replacement of the driving motor (31), possibly with the suspension means (40) or part thereof.

Advantageously, the method comprises at least one of the following further steps:

displacing at least in a vertical direction at least a part of the suspension means (40) with respect to the bearing element (11b,13b;12b,14b;41) between a first position in which the said part of the suspension means (40) is adjacent to the bearing element (11b,13b;12b,14b;41), and a second position in which the said part of the suspension means (40) is downwards distant from the bearing element (11b,13b;12b,14b;41); and/or
suspending at least the gearing box (32) (when the motor is provided with such a gearing box. Such a gearing box is not required when the driving motor is of the permanent magnet type.) by a suspension means (40,40bis) connected to a bearing element (11b,13b;12b,14b;41) selected from the group consisting of the first substantially horizontal collector pipe (11b,13b), the second substantially horizontal collector pipe (12b,14b), and a bridging element (41) forming a connection between the said first substantially horizontal collector pipe (11b,13b) and the second substantially horizontal collector pipe (12b,14b), so that the gearing box (31) extends below the average level (L1) of the first and second substantially horizontal collector pipes (11b,13b;12b,14b), whereby at least a part of the suspension means (40,40bis) is mounted movable with respect to the bearing element (11b,13b;12b,14b;41), whereby at least the gearing box (31) is movably mounted with respect to the bearing element (11b,13b;12b,14b;41); and/or
moving the suspension means (40,40bis) connected to the gearing box (31) in order to move relatively the gearing box (32) from the bearing means (11b,13b;12b,14b;41) up to a downwards position facilitating at least the maintenance of the gearing box (32) and/or the replacement of the gearing box (32), possibly with the suspension means (40,40bis) or part thereof; and/or
moving the suspension means (40,40bis) connected to the driving motor (31) and the gearing box (32) in order to move relatively the driving motor (31) and the gearing box (32) from the bearing means (11b,13b;12b,14b;41) to a downwards position facilitating at least the maintenance of the driving motor (31) and/or the gearing box (32) and/or the replacement of the driving motor (31) and/or the gearing box (32), possibly with the suspension means (40,40bis) or part thereof; and/or
connecting on a removable way the driving shaft (33) to a fan connector (24) mounted on the fan support (22), whereby enabling the displacement of the upper free end of said driving shaft (33) through a guiding piece (50) into said connector or towards said connector (24); and/or
connecting on a removable way the fan (21) onto said connector (24).

The air-cooled heat exchanger is preferably transportable as a kit.
Details and characteristics of the invention will appear from the following description in which reference is made to the following drawings of embodiments disclosed as examples only.

Brief description of the drawings

Fig. 1 is a schematic front view of an air-cooled heat exchanger assembly of the invention;
Fig. 2 is an upper view of the air-cooled heat exchanger assembly of figure 1;
Fig. 3 is an upper view of the air-cooled heat exchanger assembly of figure 1, after removal of the ring supporting means (29) and the air ring guiding element (28);
Fig. 4 is a side view of the air-cooled heat exchanger assembly of figure 1;
Fig. 5 is a partial cross section view along the line V-V of the assembly shown in figure 3, with the fan 21 separated from the fan support (22);
Fig. 6 is a partial cross section view of the assembly along line VI-VI in Figure 4;
Fig. 7 is a cross section view of a fan connector;
Fig. 8 is a cross section view of the fan connector along the line VIII-VIII;
Fig. 9 is a cross section view of a fan connector provided with a fan connection adapted for bearing fan blades;
Fig. 10 and 11 are schematic views showing the connection of the lower end of the driving shaft to the bridging element 41;
Figures 12 to 14 are front, plan and side views of the motor and its gearing box, with their distinct suspension means;
Figures 15 to 17 are front, plan and side views of a motor and its gearing box mounted a same suspension means;
Figures 18 and 19 are schematic views of a bridging element with fan connection associated to a shaft adapted to be received within the hollow of the driving shaft,
Fig. 20 is a vertical cross section showing of the connection of the fan connection with the driving shaft, while Fig. 21 is a cross section view of the connection of figure 20 along the line XXI-XXI;
Fig. 22 is a perspective view of the bridging element of the assembly of figure 1;
Fig. 23 is a view of an assembly similar to that of figure 1;
Fig. 24 is a ground view of the assembly of figure 23;
Fig 25 is a side view showing a structure adapted for suspending a series of assemblies of the invention, several assemblies can be connected for the supply of vapour or for collecting condensed water and vapour.

Description of Preferred embodiments

Figure 1 shows schematically an air-cooled heat exchanger assembly (1) comprising at least one heat exchanger unit (10) for cooling and condensing at least partly a first fluid medium (F1) flowing in at least one passage of the heat exchanger unit (10) having at least an inner face contacting the said first fluid medium and at least one outer face not contacting said first fluid medium, by means of an air flow (F2) contacting at least one outer face of the heat exchanger unit (10), whereby the said first fluid medium (F1) and said air flow (F2) are not in direct contact together, said air-cooled heat exchanger assembly (1) comprising at least:

A heat exchanger unit (10) consisting of: (a) a heat exchanger unit comprising (a1) a first heat exchanger element (11) extending between a first upper substantially horizontal distributor pipe (11a) for distributing the first fluid medium into said first heat exchanger element (11), and a first lower substantially horizontal collector pipe (11b) for collecting the at least partly condensed first fluid in said first heat exchanger element 11), and (a2) a second heat exchanger element (12) extending between a second upper substantially horizontal distributor pipe (12a) for distributing the first fluid medium into said second heat exchanger element (12), and a second lower substantially horizontal collector pipe (12b) for collecting the at least partly condensed first fluid in said second heat exchanger element (12), said second lower substantially horizontal collector pipe (12b) being advantageously in fluid connection with the said first substantially horizontal collector pipe (11b), whereby the first substantially horizontal distributor pipe (11a) is distant from the second substantially horizontal distributor pipe (12a) by a horizontal distance which is greater than the horizontal distance separating the first substantially horizontal collector pipe (11b) and the second substantially horizontal collector pipe (12b), and whereby the said first and second substantially horizontal distributor pipes (11a,12a) are forming supporting means for a fan assembly (20);
A fan assembly (20) comprising (a) a fan (21) and (b) a fan support (22) adapted to be attached to the said supporting means (11a,12a;13b,14b) of the heat exchanger unit (10), possibly with interposition of an intermediate supporting piece, said fan assembly (20) comprising at least a bearing system (23) for co-operating with the fan (21);
A driving system (30) for driving into rotation the fan (21), said driving system (30) comprising at least a driving motor (31), a gearing box (32), and a driving shaft (33) adapted to co-operate with the fan (21), whereby the driving motor (31) is adapted for driving into rotation the driving shaft (33) and the fan (21), via the gearing box (32),

With such an air-cooled heat exchanger assembly, the building and maintenance works are facilitated. Moreover, as the motor is suspended the one or the two collector pipes or a bridging element connecting said collector pipes or extending between said collector pipes, the motor acts as means stabilising the heat exchanger unit, the centre of gravity thereof being lowered. When building such heat exchanger, lighter devices for lifting in place the different parts of the heat exchanger can be used, whereby preventing some accidents or some damages during the building.
As it is shown schematically a part of the suspension means 40 can be separated from the connector pipes 11b,12b.
The motor 31 is thus placed in a cool area, i.e. protected from the sun and from the heated air flowing through the first and second heat exchanger elements (11,12), and is even located in an area with low turbulence of solid particles or dust and less or not submitted to vibration due to environmental wind or other weather conditions. The motor is also located in a more accessible area. As the motor is more accessible, it is also easier to detect possible problems by detecting higher noise level at the motor. It can also be more easily be associated with noise attenuating means, like a box or noise attenuating enclosure. The said box or enclosure can also advantageously be fire-proof or fire resistant.
The motor 31 can be of the permanent magnet type. In that case no gearing box 32 is required.
In said embodiment of figure 1, the motor 31 is operating with a gearing box. The at least a part of the suspension means (40) movable with respect to the bearing element (11b,13b;12b,14b;41) is at least (a) horizontally (arrow X) with respect to the collector pipes so as to separate the driving motor 31 from the gearing box 32, and (b) vertically (Arrow Y1) movable with respect the bearing element (11b,13b;12b,14b;41) between a first position in which the said part of the suspension means (40) is adjacent to the bearing element (11b,13b;12b,14b;41), and a second position in which the said part of the suspension means (40) is downwards distant from the bearing element (11b,13b;12b,14b;41). For example, the said part of the suspension means (40) is lowered up to the ground level, after a first horizontal movement, whereby enabling the maintenance works of the motor or its replacement at ground level.
For example the suspension means (40) of the motor (31) is provided with a plate element (401) with lateral arms (402) having adjacent to the ends with profiles (403) forming each a groove for receiving a protuberance (110b,120b) of a collector pipe (1 1b, 12b), whereby enabling a sliding of the suspension means along the collector pipes (11b, 12b).
The gearing box (32) is suspended by a distinct suspension means (40bis) connected to a bearing element selected from the group consisting of the first substantially horizontal collector pipe (11b,13b), the second substantially horizontal collector pipe (12b,14b), and a bridging element (41) forming a connection between the said first substantially horizontal collector pipe (11b,13b) and the second substantially horizontal collector pipe (12b, 14b), so that the gearing box (32) extends below the average vertical level (L1) of the first and second substantially horizontal collector pipes (11b,13b;12b,14b), whereby at least a part of the suspension means (40bis) is mounted movable (vertically - arrow Y2) with respect to the bearing element (11b,13b;12b,14b;41), whereby at least the gearing box (32) is movably mounted with respect to the bearing element (11b,13b;12b,14b;41).
In said embodiment, the said part of the suspension means (40bis) is lowered up to the ground level, whereby enabling the maintenance works of the gearing box or its replacement.
The two suspension means 40,40bis can possibly be such that they are able to move simultaneously in vertical direction. In that case, one single suspension means 40 can be used for suspending to the heat exchanger unit both motor and gearing box (see figures 15 to 17 - arrow Y1).
According to the embodiment of Fig 1, the heat exchanger assembly has moreover the following characteristics or details:

^∗ the at least part of the suspension means (40,40bis) movable with respect to the bearing element (11b,13b;12b,14b;41) is associated to the driving motor (31) and/or the gearing box (32) or in which the at least part of the suspension means (40) for the driving motor (31) movable with respect the bearing element (11b,13b;12b,14b;41) is distinct form the at least part of the suspension element (40bis) for the gearing box (32) movable with respect to bearing element (11b,13b;12b,14b;41). Two distinct suspension means are used, whereby enabling separate maintenance or replacement works at ground level when required. In such an embodiment the connection of the motor to the gearing box is advantageously mobile so as to separate the motor from the gearing box. The movement of one suspension means is advantageously connecting automatically the driving system connecting the motor to the gearing box. In a possible embodiment the driving motor is mounted on a suspension means enabling horizontal movement of the driving motor suspension means with respect to the one or more collector pipes, so as to separate the driving motor from the gearing box, before moving vertically the driving motor suspension means 40 or the gearing box suspension means 40bis.
^∗ The air cooled heat exchanger comprises a guiding piece (50) attached to a bridging element (41) connecting the said first substantially horizontal collector pipe (11b) to the second substantially horizontal collector pipe (12b), whereby said guiding piece (50) has an central open passage (52) for enabling the passage of the driving shaft (33 - shown in dashed lines), in which said guiding piece (50) is advantageously associated to one or more bearings (51). The bearings (51) have for example a part attached to the bridging element (41), and another part attached to the guiding piece (50), so that the guiding piece can freely rotate with respect to the bridging piece (41). The driving shaft (33) is suspended to the heat exchanger unit (10) through the gearing box (32) or through a system (55) for attaching (advantageously in a removable way) the driving shaft (33) or a piece connected to said shaft (33) to a bearing (51) or to the guiding piece or part thereof (50bis). This embodiment facilitates also the building and the transport of the air-cooled heat exchanger as a kit to be mounted, as quickly as possible, on the building site.
^∗ the fan support (22) is adapted to be mounted between the first upper substantially horizontal distributor pipe (11a) and the second upper substantially horizontal distributor pipe (12a), the said fan support (22) is provided with seats (220,221) for bearings (211,212) of a shaft 213 attached to the fan connection 214 on which the fan blades (215) are attached. (see figures 19 and 22). The fan support is for example made from profiles welded together so as to form an open bridge enabling the passage of air through the openings defined between the profiles. The seats (220,221) are formed by four profiles defining a substantially square opening, the square opening of the seat (221) being larger than the square opening of the seat (220). Other seat patterns are possible in function of the shape of the bearings of the shaft or supporting elements attached to said bearings. The bearing (211) is provided with a disc (211d) having a diameter smaller than the edge of the square of the seat (221), while being greater than the edge of the square of the seat (220) (but smaller than the length of the diagonal of said square of the seat (220)). The disc (212d) of the bearing (212) has a size larger than the edge of the square opening of the seat (221). The shaft (213) can so be moved vertically through the openings of the seats (220,221), whereby the discs (211d) and (212d) rest respectively on the seats (220,221). The shaft (213) has a free downwards end (213E) provided with one or more vertical lateral protuberances (213U) engaged into vertical grooves (33G) of the upper end of the driving shaft (33). Such a connection enables that the driving into rotation of the driving shaft (33) causes the driving into rotation of the fan shaft (213), as well as enabled vertical relative movement of the free end of the fan shaft (213) into the hollow of the upper end of the driving shaft (33) (see figures 19 and 20). The fan support (22) could also comprise (see Fig. 7,8 and 9) a connector (24) mounted rotatable on said fan support (22), said connector (24) comprising a hollow (25) with at least a downwards opening (26) for receiving the upper end (33U) of the driving shaft (33).
^∗ In the possible embodiment using a connector (24), the hollow (25) of the said tube shaped connector (24) and a portion of the driving shaft (33) adjacent to the said upper free end (33U) are adapted for enabling vertical relative displacement of the said upper free end (33U) of the driving shaft (33) within the said hollow (25) of the connector (24) (this is advantageous in order to take over possible thermal expansion of the driving shaft 33 and/or the heat exchange element or to take over possible length difference of the driving shaft 33 (for example due to an error during its manufacturing), while ensuring that the driving of the driving shaft (33) ensures the driving of the connector (24).

In order to facilitate the vertical relative movement between the upper end of the driving shaft (33) and the connector (24) or the fan shaft (213), a gliding means can be used. Such a gliding means is for example (a) a layer reducing the friction between said upper end of the driving shaft and the connector (24) or the fan shaft (213), said layer coating parts of the driving shaft and/or of the connector or the fan shaft (213) or an intermediate gliding element (27,24K) extending between the driving shaft (33) and the connector (24) or the fan shaft (213), whereby said gliding element can also be part of the system for connecting the driving shaft (33) to the tube or connector (24).
The hollow (25) of the connector (24) and a portion of the driving shaft (33) adjacent to the upper free end (33U) thereof are associated with interposition of a gliding means (27). The driving shaft (33) is for example hollow and has groove openings (33G) for receiving the ends of vertical keys (24K) connected to the tube (24). The tube is advantageously provided with vertical grooves (24G) extending from the free end of the tube (24). In that case, the key can be a cross element which can be moved from the upper end (24U) into the groove (24G), and thereafter within the grooves (33G).

^∗ In the embodiment of figure 7, the connector (24) comprises an upper end (24U) adapted for mounting in a removable way the fan (21) or part thereof. This is quite advantageous for the mounting operations, as well as the transporting operations.
^∗ the fan assembly (20) comprises a substantially ring guiding element (28) in which the fan (21) is adapted to extend at least partly within the said ring guiding element (28). Said ring guiding element 28 improves the working of the fan 21 and controls the air flow. Said substantially ring guiding element (28) is advantageously associated to a ring supporting means (29) for attaching it on the supporting means (11a, 12a;13b,14b), preferably in a removable way, possibly with one or more intermediate pieces.
^∗ the fan support (22) comprises a bridging element adapted to be removably attached to the ring supporting means (29) or adapted to have ends (22a,22b) for resting on the supporting means (11a,12a), said ends (22a,22b) being then advantageously covered by a portion of the ring supporting means (29), which can be provided with recesses for receiving the said ends (22a,22b).
^∗ the bearing element (11b,12b,41) is provided with a mechanical system (42) for facilitating and/or guiding the relative movement of at least the driving motor (31) and part of the suspension means (40) with respect to said bearing element (11b,12b,41). Such mechanical system can be wheels (421) which can co-operate with chains (422 shown in dashed lines) having each an end attached to an ear (423) of the arms (402).

The embodiment of air cooled heat exchanger of Fig 23 is similar to that of figure 1, except that for the said heat exchanger:

The heat exchanger unit (10) is a heat exchanger unit comprising (b1) a first heat exchanger element (13) extending between a first upper substantially horizontal distributor pipe (13a) for distributing the first fluid medium into said first heat exchanger element (13), and a first lower substantially horizontal collector pipe (13b) for collecting the at least partly condensed first fluid in said first heat exchanger element (13), and (b2) A second heat exchanger element (14) extending between a second upper substantially horizontal distributor pipe (14a), which is advantageously the first upper substantially horizontal distributor pipe (13a), for distributing the first fluid medium into said second heat exchanger element (14), and a second lower substantially horizontal collector pipe (14b) for collecting the at least partly condensed first fluid in said second heat exchanger element (14), whereby the first substantially horizontal collector pipe (13b) and the second substantially horizontal collector pipe (14b) are distant from each other; whereby said distant first and second distant substantially horizontal collector pipes (13b,14b) of the heat exchanger unit form a supporting means for a fan assembly (20);
A fan assembly (20) comprising (a) a fan (21) and (b) a fan support (22) adapted to be attached to the said supporting means (13b,14b) of the heat exchanger unit (10), with interposition of an intermediate supporting piece (28,29), said fan assembly (20) comprising at least a bearing system (23) for co-operating with the fan (21) (whereby enabling the fan to rotate with respect to the fan support 22, having the shape of a bridge);
A driving system (30) for driving into rotation the fan (21), said driving system (30) comprising at least a driving motor (31), a gearing box (32), and a driving shaft (33) adapted to co-operate with the fan (21), whereby the driving motor (31) is adapted for driving into rotation the driving shaft (33) and the fan (21), via the gearing box (32).

At least the driving motor (31) is suspended by a suspension means (40) connected to at least one bearing element selected from the group consisting of the first substantially horizontal collector pipe (13b), the second substantially horizontal collector pipe (14b), and a bridging element (41) forming a connection between the said first substantially horizontal collector pipe (13b) and the second substantially horizontal collector pipe (14b), so that at least the driving motor (31) extends below the average vertical level (L1) of the first and second substantially horizontal collector pipes (13b;14b), whereby at least a part of the suspension means (40) is mounted movable with respect to the bearing element (13b;14b;41), whereby at least the driving motor (31) is movably (advantageously removably) mounted with respect to the bearing element (13b;14b;41).
The bridging element (41) is formed in said embodiment by the ring supporting element (29), the ring air guiding element (28), the fan supporting bridge (22).
In said embodiment, the motor and gearing are located well below the collector pipes (13b) and (14b), the driving shaft (33) is shorter, while possibly, when using lengthy driving shaft, the motor and the gearing box (31,32) are near the ground level.
The air-cooled heat exchanger assembly of the embodiment of figure 1 is for example suspended on a structure (S) by the distributor pipes (11a, 12a), while the heat exchanger assembly of figure (23) is suspended by the distributor pipe (13a).
In both embodiments the driving system (30) of the fan is suspended to the heat exchanger. In the embodiment of Figure 1, the bridge (22), the ring supporting means (29), the ring guiding element (28) and the fan (21) and its shaft (213) are supported by the distributor pipes (12a,11a). In the embodiment of figure 23, the bridge (22), the ring supporting means (29), the ring guiding element (28) and the fan (21) and its shaft (213) are all suspended to the heat exchanger, via its collector pipes (13b,14b).
The embodiment of figure 23 is an embodiment enabling a fully suspended heat exchanger.
For maintaining the shaft (33) in position while displacing the gearing box (32), the driving shaft (33) can be provided with a bearing or ring (54) adapted to co-operate with pivoting arms (55) provided with a recess (55bis) for receiving a portion of the bearing (54) or ring (54). Said position can be maintained only temporarily, for example during the vertical displacement of the gearing box. The arms (55) are for example pivotably mounted on the bridge (41). The lower end of the driving shaft is provided with teeth (33T) to be engaged within a recess of the gearing box so that the gearing box can drive into rotation the driving shaft (33). (see figures 10,11)
In the embodiment of Fig 23 the ends of the distributor pipe (13a) are attached to the pillar (S), so that the assembly is suspended as shown on the left of Fig 25, while with the embodiment of Fig 1, the ends of the distributor pies (11a,12a) are placed on the pillars (S) so that the assembly is suspended.
The invention relates also to a method of building or maintaining an air-cooled heat exchanger comprising a structure (S) supporting and/or suspending at least one air cooled heat exchanger assembly (1) according to the invention (as disclosed here above), said method comprising at least one of the following steps:

displacing at least in a vertical direction at least a part of the suspension means (40) with respect to the bearing element (11b,13b;12b,14b;41) between a first position in which the said part of the suspension means (40) is adjacent to the bearing element (11b,13b;12b,14b;41), and a second position in which the said part of the suspension means (40) is downwards distant from the bearing element (11b,13b;12b,14b;41); and/or
suspending at least the gearing box (32) by a suspension means (40,40bis) connected to a bearing element (11b,13b;12b,14b;41) selected from the group consisting of the first substantially horizontal collector pipe (11b,13b), the second substantially horizontal collector pipe (12b, 14b), and a bridging element (41) forming a connection between the said first substantially horizontal collector pipe (11b,13b) and the second substantially horizontal collector pipe (12b,14b), so that the gearing box (31) extends below the average level (L1) of the first and second substantially horizontal collector pipes (11b,13b;12b,14b), whereby at least a part of the suspension means (40,40bis) is mounted movable with respect to the bearing element (11b,13b;12b,14b;41), whereby at least the gearing box (31) is movably mounted with respect to the bearing element (11b,13b;12b,14b;41); and/or
moving the suspension means (40,40bis) connected to the gearing box (31) in order to move relatively the gearing box (32) from the bearing means (11b,13b;12b,14b;41) up to a downwards position facilitating at least the maintenance of the gearing box (32) and/or the replacement of the gearing box (32), possibly with the suspension means (40,40bis) or part thereof; and/or
moving the suspension means (40,40bis) connected to the driving motor (31) and the gearing box (32) in order to move relatively the driving motor (31) and the gearing box (32) from the bearing means (11b,13b;12b,14b;41) to a downwards position facilitating at least the maintenance of the driving motor (31) and/or the gearing box (32) and/or the replacement of the driving motor (31) and/or the gearing box (32), possibly with the suspension means (40,40bis) or part thereof; and/or
connecting on a removable way the driving shaft (33) to a fan connector (24) mounted on the fan support (22), whereby enabling the displacement of the upper free end of said driving shaft (33) through a guiding piece (50) into said connector or towards said connector (24); and/or
connecting on a removable way the fan (21) onto said connector (24).

The air-cooled heat exchanger is preferably transportable as a kit. All parts of the kit have an acceptable weight, whereby enabling an easy transport, for example in containers, while facilitating the building on site.
List of reference signs used in the drawings:

1 : air cooled heat exchanger assembly
F1 : first fluid medium, such as water vapour to be at least partly condensed
F2 : air flow
10 : heat exchanger unit
11;13 : first heat exchanger element
12;14 : second heat exchanger element
11a,12a,13a : distributor pipe, for distributing the first fluid into the heat exchanger element 11 and/or 12
11b, 12b, 13b, 14b : collector pipe for collecting the at least partly condensed first fluid medium after its passage in a heat exchanger element 11/12
110b;120b : protuberance attached to a collector pipe 11b,12b,13b,14b
20 : fan assembly
21 : fan
211: fan bearing
211d : fan bearing disc
212 : fan bearing
212d : fan bearing disc
213 : fan shaft
213E : free downwards end of the shaft 213
213U : fan shaft lateral protuberance
214 : fan connection
215 : fan blade
22 : fan support
22a, 22b : fan support end of the fan support 22
220,221 : seat
23: bearing system
24 : connector
24G : vertical groove of the connector along the hollow 25
24K : vertical key (advantageously gliding)
24U : upper end of the connector
25 : hollow of the connector 24
26 : downwards opening
27 : gliding element
28 : ring air guiding element for the fan
29 : ring supporting means
30 : driving system
31 : driving motor
32 : gearing box
33 : driving shaft
33G : groove or opening of the driving shaft 33
33U : upper free end of the driving shaft 33
40; 40bis : suspension means
401 : plate element
402 : lateral arms
403 : groove profile
41 : bridging element between collector pipes of the exchanger
L1: average level of the collector pipes
X : horizontal displacement of the suspension means 40
Y1,Y2 : vertical displacement of the suspension means 40,40bis
42 : mechanical system
421 : wheels
422 : chains
50 : guiding piece for the driving shaft 33
50bis : extension of the piece 50
51 : bearings of the guiding piece 50
52 : central open passage of the guiding piece 50
54 : bearing or ring or coupling element attached to the driving shaft 33
55: attachment means of the driving shaft 33 to the guiding piece 50, so that the weight of the driving shaft is taken over by the guiding piece 50 and the suspension means 40,40bis
55bis : recess, which allow to "block" driving shaft 33, while gearing box (32) is unmounted
S : support, pillar for suspending assemblies of the invention

Claims

An Air-cooled heat exchanger assembly (1) comprising at least one heat exchanger unit (10) for cooling and condensing at least partly a first fluid medium (F1) flowing in at least one passage of the heat exchanger unit (10) having at least an inner face contacting the said first fluid medium and at least one outer face not contacting said first fluid medium, by means of an air flow (F2) contacting at least one outer face of the heat exchanger unit (10), whereby the said first fluid medium (F1) and said air flow (F2) are not in direct contact together, said air-cooled heat exchanger assembly (1) comprising at least:
- A heat exchanger unit (10) selected among the group consisting of : (a) a heat exchanger unit comprising (a1) a first heat exchanger element (11) extending between a first upper substantially horizontal distributor pipe (11a) for distributing the first fluid medium into said first heat exchanger element (11), and a first lower substantially horizontal collector pipe (11b) for collecting the at least partly condensed first fluid in said first heat exchanger element (11), and (a2) a second heat exchanger element (12) extending between a second upper substantially horizontal distributor pipe (12a) for distributing the first fluid medium into said second heat exchanger element (12), and a second lower substantially horizontal collector pipe (12b) for collecting the at least partly condensed first fluid in said second heat exchanger element (12), said second lower substantially horizontal collector pipe (12b) being advantageously in fluid connection with the said first substantially horizontal collector pipe (11b), whereby the first substantially horizontal distributor pipe (11a) is distant from the second substantially horizontal distributor pipe (12a) by a horizontal distance which is greater than the horizontal distance separating the first substantially horizontal collector pipe (11b) and the second substantially horizontal collector pipe (12b), and whereby the said first and second substantially horizontal distributor pipes (11a,12a) are forming supporting means for a fan assembly (20); and (b) a heat exchanger unit comprising (b1) a first heat exchanger element (13) extending between a first upper substantially horizontal distributor pipe (13a) for distributing the first fluid medium into said first heat exchanger element (13), and a first lower substantially horizontal collector pipe (13b) for collecting the at least partly condensed first fluid in said first heat exchanger element (13), and (b2) a second heat exchanger element (14) extending between a second upper substantially horizontal distributor pipe (14a), which is advantageously the first upper substantially horizontal distributor pipe (13a), for distributing the first fluid medium into said second heat exchanger element (14), and a second lower substantially horizontal collector pipe (14b) for collecting the at least partly condensed first fluid in said second heat exchanger element (14), whereby the first substantially horizontal collector pipe (13b) and the second substantially horizontal collector pipe (14b) are distant from each other; whereby said distant first and second distant substantially horizontal collector pipes (13b, 14b) of the heat exchanger unit are forming a supporting means for a fan assembly (20);

- A fan assembly (20) comprising (a) a fan (21) and (b) a fan support (22) adapted to be attached to the said supporting means (11a,12a) of the heat exchanger unit (10), possibly with interposition of an intermediate supporting piece, said fan assembly (20) comprising at least a bearing system (23) for co-operating with the fan (21);

- A driving system (30) for driving into rotation the fan (21), said driving system (30) comprising at least a driving motor (31),and a driving shaft (33) adapted to co-operate with the fan (21), whereby the driving motor (31) is adapted for driving into rotation the driving shaft (33) and the fan (21), directly or via an intermediate piece (32),
characterised in that:
at least the driving motor (31) is suspended by a suspension means (40) connected to at least one bearing element selected from the group consisting of the first substantially horizontal collector pipe (11b,13b), the second substantially horizontal collector pipe (12b,14b), and a bridging element (41) forming a connection between the said first substantially horizontal collector pipe (11b,13b) and the second substantially horizontal collector pipe (12b,14b), so that at least the driving motor (31) extends below the average vertical level (L1) of the first and second substantially horizontal collector pipes (11b,13b;12b,14b), whereby at least a part of the suspension means (40) is mounted movable with respect to the bearing element (11b,13b;12b,14b;41), whereby at least the driving motor (31) is movably mounted with respect to the bearing element (11b,13b;12b,14b;41).
The air cooled heat exchanger assembly of claim 1, in which the at least a part of the suspension means (40) movable with respect to the bearing element (11b,13b;12b,14b;41) is at least vertically movable with respect the bearing element (11b,13b;12b,14b;41) between a first position in which the said part of the suspension means (40) is adjacent to the bearing element (11b,13b;12b,14b;41), and a second position in which the said part of the suspension means (40) is downwards distant from the bearing element (11b,13b;12b,14b;41).
The air cooled heat exchanger assembly of claim 1 or 2, in which the intermediate piece is a gearing box (32) which is suspended by a suspension means (40bis) connected to a bearing element selected from the group consisting of the first substantially horizontal collector pipe (11b,13b), the second substantially horizontal collector pipe (12b,14b), and abridging element (41) forming a connection between the said first substantially horizontal collector pipe (11b,13b) and the second substantially horizontal collector pipe (12b,14b), so that the gearing box (32) extends below the average vertical level (L1) of the first and second substantially horizontal collector pipes (11b,13b;12b,14b), whereby at least a part of the suspension means (40bis) is mounted movable with respect to the bearing element (11b,13b;12b,14b;41), whereby at least the gearing box (32) is movably mounted with respect to the bearing element (11b,13b;12b,14b;41).
The air cooled heat exchanger assembly of claim 3, in which the at least part of the suspension means (40,40bis) movable with respect to the bearing element (11b,13b;12b,14b;41) is associated to the driving motor (31) and the gearing box (32) or in which the at least part of the suspension means (40) for the driving motor (31) movable with respect the bearing element (11b,13b;12b,14b;41) is distinct form the at least part of the suspension element (40bis) for the gearing box (32) movable with respect to bearing element (11b,13b;12b,14b;41).
The air cooled heat exchanger assembly of any one of the preceding claims, which comprises a guiding piece (50) attached to a bridging element (41) connecting the said first substantially horizontal collector pipe (11b,13b) to the second substantially horizontal collector pipe (12b,14b), whereby said guiding piece (50) has an central open passage (52) for enabling the passage of the driving shaft (33), in which said guiding piece is advantageously associated to a bearing (51) or in which said guiding piece (50) or said bridging element (41) is advantageously provided with an attachment means (55) for a bearing or a coupling element (54) associated to the driving shaft (33).
The air cooled heat exchanger assembly of any one of the preceding claims, in which the fan support (22) is adapted to be mounted between the first upper substantially horizontal distributor pipe (11a) and the second upper substantially horizontal distributor pipe (12a), the said fan support (22) comprising a connector (24) mounted rotatable on said fan support (22), said connector (24) comprising a hollow (25) with at least a downwards opening (26) for receiving the upper end (33U) of the driving shaft (33).
The air cooled heat exchanger assembly of the preceding claim, in which the hollow (25) of the said connector (24) and a portion of the driving shaft (33) adjacent to the said upper free end (33U) are adapted for enabling vertical relative displacement of the said upper free end (33U) of the driving shaft (33) within the said hollow (25) of the connector (24), while ensuring that the driving of the driving shaft (33) ensures the driving of the connector (24).
The air-cooled heat exchanger assembly of the preceding claim, in which the hollow (25) of the connector (24) and a portion of the driving shaft (33) adjacent to the upper free end (33U) thereof are associated with interposition of a gliding means (27).
The air-cooled heat exchanger assembly of any one of the claims 6 and 7, in which the connector (24) comprises an upper end (24U) adapted for mounting in a removable way the fan (21) or part thereof.
The air cooled heat exchanger assembly of any one of the preceding claims, in which the fan assembly (20) comprises a substantially ring guiding element (28) in which the fan (21) is adapted to extend at least partly within the said ring guiding element (28), whereby the said substantially ring guiding element (28) is advantageously associated to a ring supporting means (29) for attaching it on the supporting means (11a,12a;13b,14b), preferably in a removable way.
The air cooled heat exchanger assembly of the preceding claim, in which the fan support (22) comprises a bridging element adapted to be removably attached to the ring supporting means (29) or adapted to have ends (22a,22b) for resting on the supporting means (11a,12a;13b,14b), said ends (22a,22b) being then advantageously covered by a portion of the ring supporting means (29).
The air cooled heat exchanger assembly of any one of the preceding claims, in which the bearing element (11b,13b;12b,14b;41) is provided with a mechanical system (42) for facilitating and/or guiding the relative movement of at least the driving motor (31) and part of the suspension means (40) with respect to said bearing element (11b,13b;12b,14b;41).
A method of building or maintaining an air-cooled heat exchanger comprising a structure (S) supporting and/or suspending at least one air cooled heat exchanger assembly (1) according to any one of the preceding claims 1 to 12, said method comprising at least one of the following steps:
- suspending at least the driving motor (31) by a suspension means (40) connected to a bearing element selected from the group consisting of the first substantially horizontal collector pipe (11b,13b), the second substantially horizontal collector pipe (12b,14b), and a bridging element (41) forming a connection between the said first substantially horizontal collector pipe (11b,13b) and the second substantially horizontal collector pipe (12b,14b), so that the driving motor (31) extends below the average level (L1) of the first and second substantially horizontal collector pipes (11b, 13b, 12b,14b), whereby at least a part of the suspension means (40) is mounted movable with respect to the bearing element (11b,13b;12b,14b;41), whereby at least the driving motor (31) is movably mounted with respect to the bearing element (11b,13b;12b,14b;41);

- moving the suspension means (40) in order to move relatively at least the element driving motor (31) from the bearing element (11b,13b;12b,14b;41) to a downwards position facilitating at least the maintenance of the driving motor (31) and/or the replacement of the driving motor (31), possibly with the suspension means (40) or part thereof.
The method of claim 13, which comprises at least one of the following further steps:
- displacing at least in a vertical direction at least a part of the suspension means (40) with respect to the bearing element (11b,13b;12b,14b;41) between a first position in which the said part of the suspension means (40) is adjacent to the bearing element (1 1b, 13b;12b, 14b;41), and a second position in which the said part of the suspension means (40) is downwards distant from the bearing element (11b,13b;12b,14b;41); and/or

- suspending at least the gearing box (32) by a suspension means (40,40bis) connected to a bearing element (11b,13b;12b,14b;41) selected from the group consisting of the first substantially horizontal collector pipe (11b, 13b), the second substantially horizontal collector pipe (12b, 14b), and a bridging element (41) forming a connection between the said first substantially horizontal collector pipe (11b,13b) and the second substantially horizontal collector pipe (12b,14b), so that the gearing box (32) extends below the average level (L1) of the first and second substantially horizontal collector pipes (11b,13b;12b,14b), whereby at least a part of the suspension means (40,40bis) is mounted movable with respect to the bearing element (11b,13b;12b,14b;41), whereby at least the gearing box (32) is movably mounted with respect to the bearing element (11b,13b;12b,14b;41); and/or

- moving the suspension means (40,40bis) connected to the gearing box (32) in order to move relatively the gearing box (32) from the bearing swam element (11b,13b;12b,14b;41) up to a downwards position facilitating at least the maintenance of the gearing box (32) and/or the replacement of the gearing box (32), possibly with the suspension means (40,40bis) or part thereof; and/or

- moving the suspension means (40,40bis) connected to the driving motor (31) and the gearing box (32) in order to move relatively the driving motor (31) and element the gearing box (32) from the bearing element (11b,13b;12b,14b;41) to a downwards position facilitating at least the maintenance of the driving motor (31) and/or the gearing box (32) and/or the replacement of the driving motor (31) and/or the gearing box (32), possibly with the suspension means (40,40bis) or part thereof; and/or

- connecting on a removable way the driving shaft (33) to a fan connector (24) mounted on the fan support (22), whereby enabling the displacement of the upper free end of said driving shaft (33) through a guiding piece (50) into said connector or towards said connector (24);and/or

- connecting on a removable way the fan (21) onto said connector (24).