EP0045697B1 - Hydraulic apparatus permitting the disconnection of a fluid-transferring articulated arm, especially for an urgent disconnection - Google Patents

Description

The invention relates to articulated arms for the transfer (loading or unloading of a ship for example) of fluid products, of the general type comprising a base, an internal tube and an external tube articulated together, and a counterweight system, the internal tube pivoting on the base, and the external tube carrying an elbow assembly and emergency disconnection device, part of this assembly remaining integral with the vessel in emergency disconnection.

A problem encountered in this area is that of the difficulty of connecting the marine loading arms to the ship when they are unbalanced in normal operation. Another problem is that of the marine loading arms which, when they are over-balanced on the articulated assembly or under-balanced (the arm being in empty or full emergency disconnection) may tend to approach the ship with risk of shock. Another problem is that of the curve described by the end of the part of the elbow-emergency disconnection device assembly remaining integral with the external tube, when the internal tube rises, in particular in the case where the angle between the outer tube and the inner tube remains constant or varies very slowly.

We know from documents GB ― A ― 1,337,726 and US ― A ― 3,805,834 oil loading arms with two counterweights comprising a deformable parallelogram, one of the short sides of this parallelogram being in the extension of the outer arm and the other short side being articulated on the base with a beam, the internal arm constituting the other long side parallel to the beam.

There is in document GB-A-1,337,726 a counterweight on an extension of the beam and another counterweight on an extension of the internal tube or on an extension of the short side of the parallelogram articulated at the base.

In document US ― A ― 3,805,834 there exists a pair of counterweights on rear extensions of the beam and another pair of counterweights on extensions of a pair of short sides of the parallelogram considered, jacks making the connection between the beam and short sides.

In the two above documents there is an interdependence between the pivoting of the parallelogram counterweight and the pivoting of the outer tube and vice versa.

Document FR-A-2,145,783 also discloses a loading arm in which there is not, properly speaking, an internal tube and an external tube but a set of three articulated tubes, this assembly itself being articulated to a vertical filling handle and more particularly used for filling tank wagons.

An arrow comprises a movable part and a fixed part. This fixed part carries a balancing mass movable longitudinally and a mechanical transmission is established so as to link in movement, but in opposite directions, the mobile part of the boom and the balancing mass with respect to the fixed part. of this arrow.

In another loading arm known from document GB-A-2,019,347, there is a counterweight mounted on a pivoting beam on a rear extension of the internal arm.

The beam is associated with an attitude control system comprising a pair of pendulums and a pair of valves and sensor means attached to the beam to determine the attitude of the outer arm and acting on actuators of the inner arm and of beam swing control.

Finally, document FR-A-2,373,487 discloses an oil loading arm comprising a balancing system designed so as to neutralize the vertical movement of the arm regardless of the position of the arm. This system comprises a single counterweight guided so as to effect a vertical movement on a rod. The counterweight is suspended by two cables.

The invention relates to an arrangement described in document US-A-3,805,834 and corresponding to the preamble of claim 1.

• - un contrepoids mobile hydrauliquement sur le bras, à l'arrière du tube interne;
• - un vérin, sous la dépendance d'une vanne de séquence (VS), provoquant les déplacements dudit contrepoids mobile;
• - un vérin de commande du tube interne une surpression survenant dans certaines conditions de déséquilibre dans ledit vérin étant utilisée pour commander l'ouverture de ladite vanne de séquence (VS); et
• - une vanne (V1) de verrouillage du dispositif de déconnexion d'urgence.

The present invention overcomes the problems set out above and aims at a hydro-mechanical arrangement allowing, in particular, the release of an articulated arm in emergency disconnection, characterized in that it comprises:

• - a hydraulically movable counterweight on the arm, behind the internal tube;
• - a jack, under the dependence of a sequence valve (VS), causing the displacements of said mobile counterweight;
• an actuator for controlling the internal tube, an overpressure occurring under certain conditions of imbalance in said actuator being used to control the opening of said sequence valve (VS); and
• - a valve (V1) for locking the emergency disconnection device.

According to one embodiment of the arrangement according to the invention, the hydraulically movable counterweight is a slider.

According to another embodiment of this hydromechanical arrangement, the hydraulically movable counterweight is mounted in a rocker.

• - la figure 1 est une vue en élévation latérale d'une forme de réalisation possible d'un bras de transfert de produits fluides équipé conformément à l'invention;
• - la figure 2 est une vue en élévation latérale partielle et à plus grande échelle de cette forme de réalisation, le tube interne du bras articulé étant disposé à la verticale, parallèlement à l'embase;
• - la figure 3 est une vue semblable à la figure .2, mais à 90° par rapport à celle-ci;
• - la figure 4 est une vue en coupe suivant la ligne IV-IV de la figure 3, à plus grande échelle et montrant le contrepoids mobile hydrauliquement de cette même forme de réalisation, le contrepoids étant un curseur;
• - les figures 5 et 6 sont des schémas de la commande hydraulique;
• - les figures 7 à 11 sont des schémas montrant des emplacements différents du dispositif de commande du tube externe du bras; et
• - la figure 12 est un schéma représentant une autre forme de réalisation du contrepoids mobile hydrauliquement, ce contrepoids étant alors monté en bascule.

Other characteristics and advantages of the present invention will emerge from the description which follows, given with reference to the appended drawings in which:

• - Figure 1 is a side elevational view of a possible embodiment of a fluid transfer arm equipped in accordance with the invention;
• - Figure 2 is a partial side elevational view on a larger scale of this embodiment, the inner tube of the articulated arm being disposed vertically, parallel to the base;
• - Figure 3 is a view similar to Figure .2, but at 90 ° relative thereto;
• - Figure 4 is a sectional view along the line IV-IV of FIG. 3, on a larger scale and showing the hydraulically movable counterweight of this same embodiment, the counterweight being a cursor;
• - Figures 5 and 6 are diagrams of the hydraulic control;
• - Figures 7 to 11 are diagrams showing different locations of the control device of the outer tube of the arm; and
• - Figure 12 is a diagram showing another embodiment of the hydraulically movable counterweight, this counterweight then being mounted in a rocker.

In the embodiment shown in FIGS. 1 to 4 in particular, the invention is applied to an articulated arm for transferring fluid products, in particular petroleum products, between a quay installation (Q) and a ship (N) for example . In this embodiment chosen only by way of example to illustrate the application of the invention, the articulated arm comprises a base (1) and, pivotally mounted on this base, using two elbows (2) and (3) and two bearings (4) and (5), an internal tube (6) at one end of which is articulated an external tube (7). According to this arrangement, a first pivoting takes place around a vertical axis Z-Z of the base and a second pivoting occurs around a horizontal axis X-X. On a beam (8) extending, at the rear, the internal tube (6), there is the wheel (9) of the counterweight system (10) which is connected by a cable (11) to the other wheel (12 ) of the system. The outer tube (7) carries at its end an assembly (13) with elbows (14) and emergency disconnection device (15) for the connection with the ship. It should be noted that part of this assembly remains on the vessel during an emergency disconnection.

According to the invention and to remedy the problems set out above, at least one hydraulically movable counterweight (16) is provided on the beam (8) for the rear extension of the internal tube (6) of the articulated arm. More precisely, the hydraulically movable counterweight (16) is produced in the form of a cursor capable of moving on slides (17) fixed by spacers (18) both on the elbow (3) of the internal tube (6 ) and on the beam (8). The counterweight-cursor carries rollers (19) facilitating its movement on the slides (17). It is divided into two masses (16A) and (16B) connected by a plate (20) on which is articulated in (21) the rod (22) of a control cylinder (23) fixed on the internal tube (6) .

A jack (24) mounted oscillating on the internal tube (6) and the piston of which is connected to a cable (25) joining a pulley (26) fixed to the base and a pulley (27) mounted loosely on the internal tube, constitutes the control device of the internal tube.

Another cylinder (28), whatever its location, allows the control of the external tube (7). Embodiments of the location of this external tube control device will be described later.

The description of the “hydraulic” part of the hydromechanical arrangement according to the invention will follow in relation to a description given below of the general operation of an articulated arm equipped in accordance with said invention and in relation to a presentation of the hydraulic operation well said.

• En marche normale, le bras est manoeuvré pour le raccordement, le contrepoids (16) étant en position "bras équilibré vide", position (P1) figure 1. Un détecteur (29) autorise la manoeuvre. Après raccordement au navire, l'ouverture de la vanne (V1) de verrouillage hydraulique du dispositif de déconnexion d'urgence commande automatiquement le déplacement (flèche F1) du contrepoids en position "bras équilibré plein", position (P2) figure 1. Un détecteur (30) de contrepoids dans cette position au position de chargement, autorise alors l'ouverture de la vanne.(31 ) du pied ou embase du bras.

The general operation of an articulated fluid transfer arm equipped according to the invention is therefore as follows:

• In normal operation, the arm is maneuvered for connection, the counterweight (16) being in the "empty balanced arm" position, position (P1) in figure 1. A detector (29) authorizes the maneuver. After connection to the ship, the opening of the hydraulic locking valve (V1) of the emergency disconnection device automatically controls the movement (arrow F1) of the counterweight in the "balanced full arm" position, position (P2) in figure 1. A counterweight detector (30) in this position in the loading position, then authorizes the opening of the valve (31) of the foot or arm base.

In emergency disconnection of the full arm, the counterweight (16) slightly overbalances the internal tube (6) which rises.

Pressing the cylinder (32) of the emergency disconnection device locks the cylinder of the external tube (7) in position. Locking is done using normal controls.

In emergency disconnection of the empty arm, the counterweight (16) being in the "balanced full arm" position (P2), the imbalance of the internal tube (6) causes an overpressure in the cylinder (24) of the internal tube, this overpressure controls the opening of a sequence valve (VS) and the oil is directed into the cylinder (23) controlling the movement of the counterweight (16).

Consequently, as the inner tube moves, the counterweight moves (arrow F2) until equilibrium is again restored.

The external tube (7) is blocked by the pressurization of the jack (32) of the emergency disconnection device. The normal commands allow the locking position to be set.

• En service normal, le bras de chargement étant connecté au navire, l'opérateur ouvre la vanne (V1) de verrouillage du système de déconnexion. Le détecteur électrique (13A) agit automatiquement sur une électrovanne (EV1) qui met sous pression le vérin (23) de commande du contrepoids mobile (16) qui se déplace (flèche F1) en position "bras équilibré plein" (P2). Des limiteurs de débit (Ll-L2) permettent le contrôle de la vitesse de déplacement du contrepoids et des clapets pilotés (C1-C2) permettent le blocage du vérin (23) en position fixe, en cas de rupture de canalisation hydraulique.

The specifically hydraulic operation is as follows:

• In normal service, the loading arm being connected to the ship, the operator opens the disconnection system locking valve (V1). The electric detector (13A) acts automatically on a solenoid valve (EV1) which pressurizes the actuator (23) for controlling the mobile counterweight (16) which moves (arrow F1) in the "balanced balanced arm" position (P2). Flow limiters (Ll-L2) allow the speed of movement of the counterweight to be controlled and piloted valves (C1-C2) allow the cylinder (23) to be locked in the fixed position, in the event of a hydraulic pipe rupture.

In emergency disconnection, the arm being full, when the arm is connected to the vessel the selector-valve (SV1) allows Îa intercommunica tion of the two chambers of the control cylinders of the internal tube (line AB) and the external tube line (CD).

In an emergency, a solenoid valve (EV2) is energized and the cylinder (32) of the emergency disconnection device controls the disconnection of the arm, if the valve closing control stop (FdC) is open and if the valve (V1) is in the unlocked (open) position. At the same time, a blocking valve (VB) is controlled in the closed position. The actuator (28) for controlling the external tube (7) is locked in position. It should be noted that depending on the location chosen for this cylinder (28), the outer tube (7) is either blocked relative to the inner tube (6), or blocked relative to the base (1) .

With the emergency disconnection device open, the internal tube (6), slightly overbalanced by the mobile counterweight (16) rises slowly, the speed being controlled by a flow regulator (R2). The pressure in the chamber (B) of the jack (24) being lower than the setting of the sequence valve (VS) the latter remains closed and a piloted valve (VP) does not change state, the oil coming from the chamber (B) returns through the selector valve (SV1) to chamber (A). The ascent of the inner tube (6) stops when equilibrium is reached. (Internal tube near vertical.)

In emergency disconnection, the arm being empty, no detector indicating whether the arm is empty or full, it is considered that the mobile counterweight (16) is in the "balanced full arm" position P2. With the emergency disconnection device open, the external tube (7) locks as before.

The imbalance, in this case, is very important, the flow regulator · (R2) installed on the chamber (B) of the jack (24) of the internal tube (6) allows a fixed flow; therefore, the pressure in this chamber is higher than the set pressure of the sequence valve (VS) which opens. The oil under pressure coming from the chamber (B) controls the pilot valve (VP) which changes state (line P1) the oil flow passing through the regulator (R2) is directed towards the line (P1). This line also connected to the output of the sequence valve (VS) then feeds through a direction selector (S1) the chamber (B) of the jack (23) for controlling the mobile counterweight (16). The oil escapes from the chamber (B) to the tank through the solenoid valve (EV1).

The mobile counterweight (16) rises, the imbalance decreases as well as the pressure in the chamber (B) of the jack (24) of the internal tube (6). When the value of this pressure is lower than the setting of the sequence valve (VS) it closes, but the ascent of the internal tube continues slowly. The piloted valve (VP) remains in the piloted position, the pressure coming from the chamber (B) of the jack is in communication with the piloting chamber (line P1) through a flow limiter (L3); this line always feeds the ascent of the counterweight to an equilibrium position.

The change of state of the piloted valve (VP) is carried out automatically when the operator resumes control of the arm. Indeed, when the pressure is applied to the chamber (A) of the jack (24) of the internal tube (raising of the arm) line (A) of the selector-valve (SV1) the oil under pressure controls the opening of a piloted valve (CP) which drains the line (P1) towards the tank (R) of the hydraulic unit. The valve pilot orifice (VP) is no longer under pressure; it returns to the normal operating position using its return spring. During the ascent of the internal tube (6), the valve (VP) being piloted, the chamber (A) of the jack (24) of the internal tube is in communication with the reservoir of the hydraulic unit through the piloted valve (VP).

Tared valves (CT) installed between the chambers (A) and (B) of the cylinder (24) of the internal tube allow the intercommunication of these two chambers when the pressure reaches a value greater than that of the calibration of these valves, in the event malfunction of the devices described above.

In Figure 7 two curves have been shown. The curve (E1) shows the deflection of the end (O) of the outer tube (7) after disconnection, the position of said outer tube being locked relative to the inner tube (6). The curve (E2) shows the movement of the same end (O) of the outer tube (7) after disconnection, the inclination of the outer tube remaining constant relative to the vertical axis ZZ of the base, hence the clearance of the tube external to the ship. To do this, the actuator (28) for controlling the external arm acts on a movable pulley (33) connected by a cable (34) to a pulley (35) fixed relative to the base. The cylinder body (28) is mounted oscillating on the wheel (9). The detail of this mounting of the jack is shown in FIG. 8.

In the variant of FIG. 9, the cylinder body (28) is always mounted oscillating on the wheel (9) and the rod of this cylinder is connected by a yoke to the pivot (9A) of the wheel on which the pulley is fixed. (33).

In the variant shown in Figures 2 and 3, the cylinder body (28) is mounted oscillating on the beam (8) while its rod is connected by a yoke to the pivot (9A).

Other locations of the jack (28) are provided in Figures 10 and 11 of the drawings, without these choices of locations being limiting.

In FIG. 10, two jacks (28) for controlling the external tube (7) are arranged on each of the strands of a cable (36) connecting a pulley (37) fixed to the external tube (7) and a pulley (38) attached to the base.

In FIG. 11, the body of the actuator (28) for controlling the external tube (7) is mounted oscillating on the base (1) while the end of its rod is articulated at (39) to a pulley (40) crazy climb on the base. The pulley (40) is connected by a cable (41) to a pulley (42) fixed to the external tube.

In the embodiment shown diagrammatically in FIG. 12, the mobile counterweight (16) is found to be rocked on the beam (8) rear extension of the internal tube (6) but it is always controlled, and in the same way, by the jack (23). The counterweight (16) is mounted on a branch (43A) of a bent lever pivoting on the beam (8) around an axis (44), the other branch (43B) of the lever being also articulated to the rod of the control cylinder (23). The counterweight (16) is shown in this figure in two different tilting positions corresponding substantially to the positions (P1) and (P2) of the other embodiment.

Thus the actuator (23) for controlling the movable counterweight-cursor (16) can be fixed on the rear beam (8) instead of being fixed on the internal tube.

Claims (16)

1. A hydromechanical arrangement with two counterweights (10,16) for permitting particularly emergency disconnection release of an articulated fluid product transfer arm, whether filled or empty and whatever be its position, of the general type comprising a base (1), an inner tube (6) with rearward extension thereof and an outer tube (7) hingedly connected to one another, and a counterweight system with two counterweights, the inner tube (6) being pivotable to the base (1) and the outer tube carrying an elbow means (14) and emergency disconnection device, characterized in that it comprises:

- counterweight (16) hydraulically movable on the arm, rearwardly of the inner tube (6);

- a jack (23) depending on a sequential valve (VS) and controlling motions of said movable counterweight;

- jack (24) for controlling the inner tube (6), with overpressure occurring under certain unbalanced conditions in said jack (24) being used for causing said sequential valve (VS) to open;

- and, a locking valve (V1) for the emergency disconnection device.

2. An arrangement according to claim 1, characterized in that the hydraulically movable counterweight (16) is a slide moving on slideways (17) disposed on a beam (8) for rearwardly extending the inner tube (6).

3. An arrangement according to claim 1, characterized in that the hydraulically movable counterweight (16) is tippingly mounted to the beam (8) for rearward extension of the inner tube (6) of the articulated arm.

4. An arrangement according to claim 1, characterized in that another jack (28), whatever be its location, permits to control the outer tube.

5. An arrangement according to claim 4, characterized in that the body of the jack (28) is pivotably mounted to the wheel (9) of the conventional counterweight system (10), whereas its rod is hingedly connected to a movable pulley (33) connected through a cable (34) to a pulley (35) stationary relative to the base.

6. An arrangement according to claim 4, characterized in that the body of the jack (28) is pivotably mounted to the rearward beam (8), whereas its rods is connected through a shell to the pivot (9A) of the wheel (9) to which the pulley (33) is secured.

7. An arrangement according to claim 4, characterized in that two jacks (28) for controlling the outer tube (7) are disposed on each of the wires of a cable (36) connecting a pulley (37) secured to the outer tube (7) and a pulley (38) secured to the base.

8. An arrangement according to claim 4, characterized in that the body of the control jack (28) for the outer tube (7) is oscillatingly mounted to the base (1) whereas the end of the rod thereof is hingedly connected to a pulley (40) mounted idle to the base, said pulley (40) being connected through a cable (41) to a pulley (42) secured to the outer tube.

9. An arrangement according to any one of claims 1 to 8, characterized in that it comprises a hydraulic station, said sequential valve (VS) in connection with said jacks (23, 24, 28) and the jack (32) of the emergency disconnection device, such that, the counterweight (16) being in the "filled balanced arm (P2)" position, unbalance in the inner tube (6) causes overpressure in the jack (24) of the inner tube, such overpressure causing said sequential valve to open, thereby actuating the jack (23) for controlling motion of the counterweight (16).

10. An arrangement according to claim 9, characterized in that said hydraulic station comprises an electric valve (EV1) for pressurizing in normal operation, the articulated arm being connected to the loading or unloading point (for example, a vessel), the jack (23) for controlling the movable counterweight (16) which moves to the "filled balanced arm (P2)" position, the locking valve (V1) for the disconnection system having been opened.

11. An arrangement according to any one of claims 9 and 10, characterized in that the flow rate limiters (L1, L2) control the speed of displacement of the movable counterweight (16).

12. An arrangement according to any one of claims 9 to 11, characterized in that piloted valve means (C1, C2) permit to block in a fixed position the jack (23) for controlling the movable counterweight in the event that the hydraulic pipe should be broken.

13. An arrangement according to any one of claims 9 to 12, characterized in that the hydraulic station comprises a valve selector (SV1) to permit intercommunication of both chambers of the control jacks for the inner tube and the outer tube in emergency disconnection, with the arm being filled and connected to the vessel.

14. An arrangement according to any one of claims 9 to 13, characterized in that the hydraulic station moreover comprises an electric valve (EV2) which is energized in case of emergency so that the jack (32) of the emergency disconnection device causes disconnection of the arm, the control jack for the outer tube also comprising a blocking valve (VB) for blocking in case of emergency the control jack (28) for the outer tube (7) either relative to the inner tube (6) or relative to the base (1).

15. An arrangement according to any one of claims 9 to 14, characterized in that the control jack for the inner tube comprises a flow rate regulator (R2) for controlling the ascending speed of the inner tube (6) and a piloted valve (VP) such that, in emergency disconnection with the arm being filled and pressure in one of the chambers of the jack (24) being lower than the setting of the sequential valve (VS), the latter remains closed and, the piloted valve (VP) not changing its state, the oil from said chamber flows back through the valve selector (SV1) to the other chamber of jack (24).

16. An arrangement according to claim 15, characterized in that upon emergency disconnection and the arm being empty, said flow rate regulator (R2) provides for fixed flow rate such that pressure in the mentioned chamber of the jack (24) is higher than the setting pressure of the sequential valve (VS), which opens, so that the piloted valve (VP) changes its state and one of the chambers of the jack (23) for the movable counterweight (16) is fed.

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