WO2019012568A1 - Lifting machine for tube bundles for heat exchangers - Google Patents

Abstract

The present invention relates to the heavy mechanical industry. More in detail, the invention relates to a lifting machine (1 ) for tube bundles for heat exchangers, where each tube bundle (2) comprises a plurality of parallel tubes whose ends are blocked by at least one tube plate (21) and a plurality of diaphragms (22) parallel to one another. Said lifting machine (1) comprises: - a supporting frame (5) with two ends (51, 52) and a central body (53) having a main direction of development (x) parallel to the tubes of said tube bundle (2); - first caliper type gripping means (3) for said tube bundle (2), associated with the central body (53) of said supporting frame (5), adapted to embrace said plurality of tubes in the area of said diaphragms (21); - second filiform type gripping means (4) for said tube bundle (2), associated with the two ends (51, 52) of said supporting frame (T), adapted to act on said tube bundle (2) near the ends thereof; - motor means (M) adapted to feed a utility hydraulic circuit; - a hydraulic control unit (C).

Description

LIFTING MACHINE FOR TUBE BUNDLES FOR HEAT EXCHANGERS

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Field of application

The present invention relates to the heavy mechanical industry.

More in detail, the invention relates to a lifting machine for tube bundles of heat exchangers.

Background art

Tube bundles of heat exchangers consist of a plurality of parallel tubes, the ends whereof are blocked by one or two thick perforated plates, called tube plates, delimiting, together with the outer jacket, the volume occupied by the tubes, where the heat exchange takes place, and of a plurality of diaphragms, interposed between said plates, which are also perforated and able to support the pipes to prevent them from bending, as well as creating an appropriately twisting path for the cooling fluid.

During the construction and maintenance of heat exchangers, it is necessary to move the tube bundles in several passages by means of lifting machines.

From patent EP 2 084 097 A1 , a lifting machine for tube bundles of heat exchangers is known comprising:

- a support frame having a main development direction parallel to the longitudinal axis of a tube bundle;

- caliper type gripping means (for the tube bundle, associated with of said supporting frame, adapted to embrace said plurality of tubes in the area of said diaphragms;

- motor means adapted to feed a utility hydraulic circuit. Said frame is hung by means of ropes to crane lifting and handling means.

Said gripping means substantially comprise a first and a second jaw adapted to transversely embrace the tube bundles during the handling thereof.

Each jaw comprises two arms, having a lower free end and an upper end for connection to said supporting frame.

The arms of each jaw are rotatably associated with each other at the upper end thereof.

The rotation movement of the single arms around their ends for connection to the supporting frame causes the jaw to open and close.

The movement of the two arms is synchronous and symmetrical with respect to a vertical plane passing through said main development direction.

Traditional lifting machines are designed to embrace the tube bundles only in the central portion thereof, at the diaphragms.

Tube bundles have a considerable flexibility which increases with length and therefore their end portions, weighted down by the tube plates, if not adequately supported tend to bend downwards, with the risk of damaging to the whole bundle.

Disclosure of the invention

The invention aims to overcome these limits by implementing a lifting machine for tube bundles of heat exchangers that is functional, efficient, solid, compact in size and extremely practical in use, adaptable to any size of tube bundles, to facilitate any operation of moving the tube bundles, preserving them from damage.

Such objects are achieved with a lifting machine for tube bundles for heat exchangers, where each tube bundle comprises a plurality of parallel tubes whose ends are blocked by at least one tube plate and a plurality of diaphragms parallel to one another, where said lifting machine comprises:

- a supporting frame with two ends and a central body having a main direction of development parallel to the tubes of said tube bundle;

- first caliper type gripping means for said tube bundle, associated with the central body of said supporting frame, adapted to embrace said plurality of tubes in the area of said diaphragms;

- motor means adapted to feed a utility hydraulic circuit;

- a hydraulic control unit,

characterized in that it comprises second filiform type gripping means for said tube bundle, associated with the two ends of said supporting frame, adapted to act on said tube bundle near the ends thereof.

According to a first aspect of the invention, said second filiform type gripping means comprise at least a first and a second inextensible cable.

Advantageously, said first and said second cable end with hooks.

In a preferred variant of the invention, said two ends of said supporting frame comprise a first and a second pair of beams and said second filiform type gripping means comprise a first and a second pair of cables associated with said first and second pair of beams.

In particular, said first and said second pair of cables comprise hooks adapted to be engaged by a lifting bundle.

Advantageously, said first and said second pair of beams comprise telescopic connecting means. According to further aspects of the invention, said lifting machine comprises first actuator means, which can be operated by means of said hydraulic control unit, for adjusting the length of said second filiform type gripping means, and second actuator means, which can also be actuated via said hydraulic control unit, for causing the sliding of said first and said second pair of beams of said supporting frame through said telescopic connecting means.

Furthermore, said first caliper type gripping means comprise at least one jaw.

In a preferred variant, said at least one jaw comprises at least two arms joined to one another, each arm having a first and a second end, where the first ends of said arms are slidingly associated with said supporting frame and can translate in a direction transversal to its main direction of development.

Advantageously, the second ends of each arm of said at least one jaw comprise a supporting pedestal for said diaphragms.

According to a further aspect of the invention, said lifting machine comprises third actuator means to cause sliding of said first ends of said arms of said at least one jaw, which can be activated by said hydraulic control unit.

In particular, said first, second and third actuator means comprise hydraulic pistons connected to an oil pump.

The lifting machine for tube bundles of heat exchangers according to the invention has many advantages.

Said second filiform type gripping means associated with the two ends of said supporting frame act on said tube bundle near its ends, where heavy tube plates are normally present, supporting them and thus avoiding bending and deformation of the end portions of the tube ends caused by the weight of the cantilevered portions of the beam.

The use of cables makes the lifting machine light and not bulky, favorable conditions especially during transport.

Said first actuator means allow regulating the length of said cables for controlling the lifting of the tube bundle. Each cable is connected to a respective actuator means so that the regulation is totally independent: this allows ensuring the perfect balance of the tube bundle along its longitudinal axis, especially in cases where the two head tube plates have a different conformation, and consequently weight.

The hooks provided at the ends of the cables allow an easy and quick connection with the tube bundles. This connection can advantageously take place directly on the tube plates, when the latter are provided with special rings or eyebolts. The tube plates are thus hung to the lifting machine.

The configuration of the machine which provides that each end of said support frame is provided with two cables advantageously allows the use of lifting bundles for lifting the tube bundle.

Each cable is hooked to one end of a lifting bundle so as to create a sort of pedestal which supports said tube bundle from the bottom.

Also in this case, each cable is connected independently to one of said first actuator means: advantageously, if the tube bundle during the lifting step is rotated axially, it is possible, by acting on the different length of the two support cables of the lifting bundle, to straighten and orient the beam axially.

By varying the length of the cables, it is also advantageously possible to compensate for any errors in positioning the lifting bundle below the tube bundle. In fact, the lifting bundle can hardly be positioned symmetrically beneath the tube bundle: this error could cause torsional deformations of the beam during its movement and for this reason, these errors must be corrected and compensated.

The ends of said supporting frame comprise two beams, each of which is connected to one of said cables: advantageously, said beams comprise telescopic connecting means, which allow the frame to vary its length to adapt to different lengths of tube bundles, making the lifting machine even more efficient. Furthermore, during the transport and handling of the machine, the telescopic connections can be retracted making the frame, and consequently the machine, more compact and less cumbersome.

Said second filiform type gripping means may also be used to fix the lifting machine to transport or packaging means.

Said first caliper type gripping means comprise two-arm jaws. Unlike traditional machines, where the arms are rotatably coupled to allow the two arms to rotate reciprocally to open and close the jaw, in the lifting machine object of the invention, the arms are slidably associated with said supporting frame in a transverse direction to its main development direction.

The two arms of the same jaw are moved by a single actuator, i.e. by said second actuator means, to ensure the opening and closing of the jaw in a symmetrical manner with respect to the axis of the tube bundle, to ensure greater stability.

Also in this case, the transverse sliding of the jaw arms allows a reduction in the overall dimensions of the entire lifting machine during transport.

Brief description of the drawings

The advantages of the invention shall appear more clearly from the following description of a preferred embodiment, made by way of an indicative and non-limiting example with reference to the figures, in which:

Figs. 1 and 2 show a side view and in front view, respectively, of a lifting machine for tube bundles of heat exchangers according to the invention;

Figs. 3 and 4 show a longitudinal section of the lifting machine in Fig. 2 along two mutually parallel planes;

Figs. 5 and 6 show a cross section of the lifting machine in Fig. 1 along two mutually parallel planes;

Figs. 7-9 show a a side view, a front view and a cross section, respectively, of the lifting machine in Figs. 1 and 2 in action on a first type of tube bundle;

Figs. 10 and 1 1 show a side view and a front view, respectively, of the lifting machine in Figs. 1 and 2 in action on a second type of tube bundle.

Detailed description of a preferred embodiment of the invention

With reference to Figures 1 -6, a lifting machine 1 for tube bundles 2 of heat exchangers is shown.

The tube bundles 2 comprise a plurality of parallel tubes along a longitudinal main development axis y and having the ends locked by a first and a second tube plate 21 , and a plurality of diaphragms 22 interposed between said two tube plates 21 .

Said diaphragms 22 are inferiorly connected by sheets. Said lifting machine 1 essentially comprises a supporting frame 5, first 3 and second 4 gripping means for said tube bundle 2, motor means M adapted to feed a utility hydraulic circuit and a hydraulic control unit C for all the mechanisms present on the machine 1 .

Said supporting frame 5 comprises two ends 51 , 52 and a central body 53. It is substantially shaped like a beam and has a main development direction x parallel to the longitudinal axis y of the tube bundle 2 which the machine 1 can lift.

At the upper ends of said supporting frame 5, rings 54 are provided for connecting to special ropes F, or chains, adapted to cooperate with arms of a crane.

Said first gripping means 3 are caliper type, are associated with said body 53 of said supporting frame 5 and are adapted to embrace said tube bundle 2 on the tubes or at said diaphragms 22.

In the illustrated variant, said first caliper type gripping means 3 comprise two jaws 30.

Each jaw 30 comprises two arms 31 , 32 coupled together.

Each arm 31 , 32 has a substantially L-shaped development, a boxlike section, and comprises a first 31 a, 32a and a second 31 b, 32b end.

The second ends 31 b, 32b of said arms 31 , 32 are free and comprise a pedestal 33 for supporting said diaphragms 22. In particular, said pedestail 33 is adapted to rest on the connecting sheets of the diaphragms 22 for greater grip stability.

In the illustrated variant, said pedestal 33 is fixed; alternatively, said pedestal 33 may be of the floating type, to better adapt to the geometry and to the size of the beam 2. Moreover, in the illustrated variant, said second ends 31 b, 32b are firmly associated with the central portion of the arms 31 , 32. In alternative variants, said second ends 31 b, 32b may be rotatably associated with the central portion of the arms 31 , 32, controlled by actuators, to facilitate the gripping or release step thereof.

With particular reference to the cross-section in Figure 6, the first ends 31 a, 32a of said arms 31 , 32 are slidably associated with said supporting frame 5 in a direction transverse to its main development direction x.

The transversal sliding of said arms 31 , 32 causes the opening and closing of the respective jaw 30, to tighten more or less the tube bundle 2 being lifted, adapting to the most varied diameters of the tube bundles.

The lifting machine 1 according to the invention can in fact lift, preferably but not exclusively, tube bundles 2 with variable diameters between 400 and 3000 mm.

Said lifting machine 1 comprises third actuator means for sliding said first ends 31 a, 32a of said arms 31 , 32 of said jaws 30 with respect to said supporting frame 5.

In particular, said third actuator means comprise an actuator 10 for each jaw 30: in this way, it is possible to vary the working width of the two jaws 30, also diversifying them according to their grip point on the tube bundle 2.

The horizontal sliding movement of the two arms 31 , 32 of each single jaw 30 is instead coordinated and symmetrical with respect to the main development direction x of the supporting frame 5.

Said second gripping means 4 are of filiform type, they are associated with the ends 51 , 52 of said supporting frame 5, and are adapted to act on said tube bundle 2 near the end tube plates 21 thereof.

In the illustrated variant, said second filiform type gripping means 4 comprise a first 41 a, 41 b and a second 42a, 42b pair of cables, each pair associated with an end 51 , 52 of the frame 5.

The cables 41 a, 41 b, 42a, 42b are of the inextensible type, and said lifting machine 1 comprises first actuator means for adjusting the length of said cables.

In particular, said first actuator means comprise an actuator 8 for each cable 41 a, 41 b, 42a, 42b.

Said cables 41 a, 41 b, 42a, 42b end with hooks 6.

Said hooks 6 are adapted to be engaged by a lifting bundle 7 which, during use, is arranged to wrap, at least partially, and embrace said tube bundle 2 from the bottom.

In a variant not shown, said hooks 6 may cooperate directly with said tube bundle 2, engaging with suitable rings or eyebolts present on the tube plates 21 . During transport of the lifting machine, they can engage with the transport or packaging means.

Said second filiform type gripping means 4 comprise, for each cable 41 a, 41 b, 42a, 42b, a pivoting pulley 55, adapted to deviate the respective cable (Figure 2) so that the latter is tangent to the tube bundle 2 at the gripping point. The inclination of the pulleys 55 is particularly noticeable in the case of large diameter tube bundles 2. With particular reference to the sections in Figures 3 and 4, each pulley 55 is supported by a bracket 56 rotatable on a pin 57 stably associated with the respective end 51 , 52 of the frame 5. With particular reference to Figures 7-9 and 10-1 1 , a lifting machine 1 is shown in operation on two different types of tube bundles 2.

Figures 7-9 relate to tube bundles 2 having two tube plates 21 .

Figures 10-1 1 instead relate to U-shaped tube bundles 2 having two horizontal upper and lower tube portions joined at one end by a special curve 23, and at the opposite end connected by a single tube plate 21 .

Since the tube bundles 2 may have different lengths, and since it is essential for the machine 1 according to the invention to act on the ends of the bundle 2 to prevent bending and deformation of the tubes subjected to a concentrated load at the ends due to the presence of the tube plates 21 , it is necessary that the supporting frame 5 can vary its length, to bring said second filiform type gripping means 4 near the tube sheets 21 .

For this purpose, as will be better appreciated from the side views in Figures 7 and 10, the two ends 51 , 52 of said supporting frame 5 comprise a first 51 a, 51 b and a second 52a, 52b pair of beams provided with telescopic connecting means.

Said pairs of beams 51 a, 51 b, 52a, 52b substantially act as an extension for the body 53 of said supporting frame 5.

In this case, the cables 41 a, 41 b, 42a, 42b of said second gripping means 4 are respectively associated with said beams 51 a, 51 b, 52a, 52b.

Said lifting machine 1 comprises second actuator means for sliding said first 51 a, 51 b and said second 52a, 52b pair of beams with respect to the body 53 of said supporting frame 5.

With particular reference to the longitudinal section in Figure 4, said second actuator means comprise an actuator 9 for each pair of beams 51 a, 51 b, 52a, 52b: the telescopic axial sliding movement of each pair of beams 51 a, 51 b, 52a, 52b with respect to the body 53 of the supporting frame 5 is independent.

Each pair of beams 51 a, 51 b and 52a, 52b can thus protrude more or less from the supporting frame 5 to adapt to the different lengths and configurations of the tube bundle 2, and possibly balance the beam in the longitudinal direction, bringing the overall center of gravity on the median axis of the central body 53. For example, in the case of a U-shaped tube bundle, where the weight of the tube plate 21 only affects one side, the pair of beams 52a, 52b, facing towards the beam curve, will protrude more from the frame 5 to balance the overall weight (Figure 10), keeping the lifting machine 1 and the relative tube bundle 2 horizontal during the lifting step.

Said first 8, said second 9 and said third 10 actuator means comprise hydraulic pistons driven by an oil pump.

Alternatively, electric actuators may be used.

The invention has been described with reference to a lifting machine for tube bundles of heat exchangers, but more generally it may be used for lifting substantially cylindrical bodies, such as tanks, and particularly for tanks with non-homogeneous weight along their longitudinal axis.

Claims

1 . Lifting machine (1 ) for tube bundles for heat exchangers, where each tube bundle (2) comprises a plurality of parallel tubes whose ends are blocked by at least one tube plate (21 ) and a plurality of diaphragms (22) parallel to one another, where said lifting machine (1 ) comprises:

- a supporting frame (5) with two ends (51 , 52) and a central body (53) having a main direction of development (x) parallel to the tubes of said tube bundle (2);

- first caliper type gripping means (3) for said tube bundle (2), associated with the central body (53) of said supporting frame (5), adapted to embrace said plurality of tubes in the area of said diaphragms (21 );

- motor means (M) adapted to feed a utility hydraulic circuit;

- a hydraulic control unit (C),

characterized in that it comprises second filiform type gripping means (4) for said tube bundle (2), associated with the two ends (51 , 52) of said supporting frame (T), adapted to act on said tube bundle (2) near the ends thereof.

2. Lifting machine (1 ) according to claim 1 , characterized in that said second filiform type gripping means (4) comprise at least a first

(41 a, 41 b) and a second (42a, 42b) inextensible cable.

3. Lifting machine (1 ) according to claim 2, characterized in that said first (41 a, 41 b) and said second (42a, 42b) cables end with hooks (6).

4. Lifting machine (1 ) according to claim 1 , characterized in that said two ends (51 , 52) of said supporting frame (5) comprise a first (51 a, 51 b) and a second (52a, 52b) pair of beams and that said second filiform type gripping means (4) comprise a first (41 a, 41 b) and a second (42a, 42b) pair of cables associated with said first (51 a, 51 b) and second (52a, 52b) pair of beams.

5. Lifting machine (1 ) according to claim 4, characterized in that said first (41 a, 41 b) and said second (42a, 42b) pair of cables comprise hooks (6) adapted to be engaged by a lifting bundle (7).

6. Lifting machine (1 ) according to claim 4, characterized in that said first (51 a, 51 b) and said second (52a, 52b) pair of beams comprise telescopic connecting means.

7. Lifting machine (1 ) according to claim 1 , characterized in that it comprises first actuator means (8) for regulating the length of said second filiform type gripping means (4), which can be activated by said hydraulic control unit (C).

8. Lifting machine (1 ) according to claim 6, characterized in that it comprises second actuator means (9) to cause sliding of said first (51 a, 51 b) and said second (52a, 52b) pair of beams of said supporting frame (5) by means of said telescopic connecting means, which can be activated by said hydraulic control unit (C).

9. Lifting machine (1 ) according to claim 1 , characterized in that said first caliper type gripping means (3) comprise at least one jaw (30).

10. Lifting machine (1 ) according to claim 9, characterized in that said at least one jaw (30) comprises at least two arms (31 , 32) joined to one another, each arm (31 , 32) having a first (31 a, 32a) and a second (31 b, 32b) end, where the first ends (31 a, 32a) of said arms (31 , 32) are slidingly associated with said supporting frame (5) and can translate in a direction transversal to its main direction of development (x).

1 1 . Lifting machine (1 ) according to claim 10, characterized in that the second ends (31 b, 32b) of each arm (31 , 32) of said at least one jaw (30) comprise a pedestal (33) for said diaphragms (22).

12. Lifting machine (1 ) according to claim 10, characterized in that it comprises third actuator means (10) to cause sliding of said first ends (31 a, 32a) of said arms (31 , 32) of said at least one jaw (30), which can be activated by said hydraulic control unit (C).

13. Lifting machine (1 ) according to claims 7, 8 and 12, characterized in that said first (8), said second (9) and said third (10) actuator means comprise hydraulic pistons connected to an oil pump.