DE688360C - Tank stabilization system for ships - Google Patents

Description

Tank stabilization system for ships Addition to patent 63o 637 Das The main patent relates to a tank stabilization system for ships, in which the tank liquid movement caused only by the ship vibrations to be damped and by a Locking device is controlled, each when the largest liquid level difference is reached closed and when the ship passes through its central position or a little later is opened. The tank liquid is held in its end positions for a while, so that there is a meandering curve for the diagram of the tank liquid movement results. A locking device is used in the exemplary embodiment of the main patent alternately acting non-return valve, which is closed after the flow process has ended closes automatically in the tanks and some time later by a servo motor inevitably opens. This version has the disadvantage that the closing time for the flap is not precisely defined and the flap oscillates back and forth. This distorts the diagram of the tank liquid movement and the damping effect degraded.

- To avoid this disadvantage, the first additional patent 666 374 suggested also the closing time for the flap in an inevitable to bring the desired phase relationship to the ship vibration to be damped. Of the The closing time should therefore not depend on the tank liquid movement itself, but rather as well as the time for the opening of the flap is derived from the ship's vibration will. However, this mode of operation has the disadvantage that the control unit from which the commands for opening and closing are given in time with the ship's vibrations can deliver the closing command at a moment when the tank liquid movement not yet for Peace has come or has already passed its turning point the tank liquid is already flowing back in both cases becomes the diagram area enclosed by the curve of the tank liquid movement reduced, there is a loss of damping effect. The present invention avoids this disadvantage in that the command for holding the tank liquid derived directly from a device indicating the tank liquid movement will. When this device displays the tank liquid speed o, will the shut-off device is inevitably closed. The release of the tank liquid is expediently controlled in a known manner by the expiry of a timing relay, its Activation of the control device that is also otherwise provided for the system is carried out will. The easiest way to display the state of movement of the tank liquid a pendulum flap is used, which has a vertical position when the tank liquid is at rest occupies, while it deflects with flowing tank liquid. Another example one suitable motion indicator is the Woltman wing.

In tank stabilization systems with activation of the tank liquid movement by means of a hoisting machine that can be switched over in time with the ship's vibrations known, except for the normal, the ship vibrations simulating control unit for the periodic switching of the conveying direction indicates the movement of the tank liquid Provide device in the form of a float and the deflections of both devices with respect to to compare their phase position with each other. The phase shift of the tank liquid movement gives way with respect to the ship vibrations from the desired value; so be through the interaction of both devices additional control commands in the sense of elimination given this deviation: If the correct phase shift is set again, then the switchover commands are given by the normal control unit alone. the In contrast, the device according to the invention delivers during each half cycle of a ship's oscillation a control command for closing the shut-off device in the air connection duct without adding another control unit. The invention also relates to non-activated T anchor stabilization systems for the control of which other aspects are decisive, so that the control measures applied when the systems are activated are not straightforward are transferable to non-activated systems.

The invention .soll will be explained in more detail with reference to the figures. The diagrams in FIGS. R and a serve to explain the basic concept of the invention and the benefits achieved. Fig. 3 shows a complete embodiment of a tank stabilization system controlled according to the invention using a Woltman wing for indicating the soak movement, and in Fig. 4 is one for execution the inventive concept suitable pendulum flap shown. For the sake of simplicity in the following description it is assumed that the tank stabilization system serves to dampen rolling movements and uses water as the tank liquid will.

In FIG. Z, curve a denotes the course of the assumed sinusoidal rolling motion of the ship; b is the curve of the tank water movement. -The ordinates mean the roll angle for the first curve and the Tanl .-% water level difference between the two working tank halves for the second curve. At points z, 3, 5 ..., which are near the passage of the ship through its central position, the tank water movement is released by opening the shut-off device, so that the tank water flows over from the port tank to the starboard tank or vice versa. As soon as the largest or smallest water level in .den tanks is reached, ie as soon as the speed of the tank water has become o, the shut-off device in the connecting channel of the two tank halves should be closed so that the tank water does not flow back; but is held until the following opening time of the shut-off device. The closing of the shut-off device takes place in points 2, 4. . . instead of; and the distances 2-3, 4-5 ... correspond to the holding time of the tank water. The control commands must be given with reference to the ship's vibrations so that the most favorable phase shift required for effective damping exists between tank water movement and rolling movement, which z. B. should be about 9o ° with resonance excitation of the ship by the sea. You can capture the points i, 2, 3 ... by a control unit that z. B. consists of a roll protractor and a phase regulator connected in series with it. while the holding time of the tank water is maintained by time relays with an adjustable delay time.

In order to achieve the best possible damping effect, the control unit must deliver the closing command when the tank water movement comes to a standstill has come. However, since the control unit is his Commands from the Derives rolling movements of the ship, becomes the closing time obtained in this way usually not with the moment of reversal of the movement of the natural tank water oscillation coincide. The closing command will z. B. before reaching the highest Given water level, approximately at point 7 of curve b. The curve b then takes the dashed modified course 6-7-8-g. So there is a loss of diagram area which is indicated by hatching. But since the size of the diagram area a direct measure of the magnitude of the damping effect is the performance of the Stabilization system also correspondingly lower; it is not being used to the full.

In Fig. 2 the conditions are in the case of a closing command that comes too late reproduced when the tank water is already available before the closing command is received reverses its direction of movement. The one indicated by hatching also occurs Loss of diagram area.

If you wanted the best utilization of the system by one after reaching it the check valve that closes automatically when the water level difference is greatest try to get, as provided in the embodiment of the main patent then there are even more unfavorable conditions due to the commuting back and forth the flap; during the closing process, which does not necessarily take place, the flow process disturbed, and it can continue to occur disadvantageous changes in the phase shift.

According to the invention, the disadvantages of the main patent and after the first additional patent known designs avoided that the command for holding the tank water from a pendulum flap, a Woltman wing or a similar device takes place exactly at the reversal point of the tank water movement, which is an inevitable closing of the shut-off device by a servo motor (Electromagnet, hydraulic cylinder or the like). One could assume that a given ship is only very small in the most varied of circumstances If the amount deviates from its natural oscillation time, the tank water movement could indicating device also doubles as a control device for monitoring the serve the entire tank water oscillation, - by the zero contact on this device, which is assigned to the tank water speed o, the time relay switches on, from which the shut-off device is opened after the delay time has elapsed. Such ideal conditions are unlikely to occur in practice. It is advisable therefore, the stabilization system in any case with one of the previously common control devices to equip the opening time depending on the ship's vibrations supplies for the shut-off device and expediently still with a phase regulator for the setting of the most favorable phase shift is provided.

In the case of the version known from the additional patent 666 374, if in the point? the curve b (Fig. i and 2) the closing command takes place, the shut-off device closed at the same moment and during the delay time t1 of the hold-open relay kept closed, regardless of the state of movement of the tank water. According to of the invention, the shut-off device is always closed when the the tank water movement indicating the zero contact (that of the tank water speed o is assigned). The starting point for the relay time can also be commanded by the control unit, i.e. located in point 7; however, has this command initially no effect on the shut-off device, only after the relay time has expired t2 the shut-off device is opened. By the control according to the invention So the ship stabilization system is always operated at its best efficiency.

3 shows one equipped with the controller according to the invention Anti-roll system. The ship drawn in cross-section contains on the starboard and on the port side j e a tank 12 or 13, which is below through a water channel 14 and above through an air duct 15 are in communication with one another. -The shut-off device could be arranged both in the water channel and in the air channel. In the present The trap is provided as a shut-off device in the air duct 15, the flap 16. Open that and closing the flap is carried out by an electromagnet 17. The axis of the associated Armature 18 is provided at its end with a backdrop i9 into which the pin of a engages lever 2o seated on the axis of rotation of the flap. If the magnet is excited, so the armature is attracted against the pressure of the spring 21 and the flap 16 open. When the magnet is de-energized, the spring 21 moves the armature forward snapped and the flap closed.

The flap is operated in conjunction with a control unit with a Woltman wing for displaying the speed of the tank water. The control unit 2 can be of any type, e.g. B. from a roll angle meter with phase regulator exist. The establishment of such a control unit needs im individual not to be explained in more detail, since such devices are known and not form the subject of the invention. For the present consideration it is sufficient to the interaction of the contact devices of the control unit with the contacts of the Woltman wing to describe those evoked by these commands To track effects on the butterfly valve 16. From the control unit only the Contact device shown, which consists of a seated on the shaft of the control unit Contact arm z3 and two contact segments 24 and 25 consists. The contact arm 23 moves according to the rolling movements of the ship and is so adjusted; that he is in a point in time derived from the rolling movement, which - approximately at point 7 in FIGS. I and 2 correspond by its central position with respect to the contact segments 24 and 25 goes. The positive pole of a power source is led to the contact arm 23 while the contact segments 24 and 25 via time relays 26 and 7 to the negative pole of this power source are connected. A normally open contact 28 or 29 is assigned to each time relay; these contacts work with a pick-up delay. The excitation winding of the electromagnet 17 is connected on the one hand to the negative pole of the power source, on the other hand via two parallel branches containing the contacts 28 and 29 to the contact segments 24 and 25 of the control unit, i.e. an.den. Positive pole of the power source connected, as soon as the contact arm 23 has left its central position and with 24 or 25 contact power.

The commands (contacts) of the j control unit 22 are from the @ Woltman wing 30 arranged in the water channel 14, which also has a from contact arm 31 and the segment 3a existing contact device is assigned. At the water speed o, the contact arm 31 has the position shown, the contact is therefore broken; when the tank water is flowing, this arm strikes more or less to the right and slides over segment 32, so make contact. The contact arm 31 is also on the positive pole of the power source. Connected in parallel to segment 32 are two relays 33 and 34, the other are connected to the negative pole of the power source. The normal relay 33 operates the Changeover contact 35. When the relay 33 is de-energized, the contact lever is through the spring 37 placed to the right, while when the relay is energized it rests on the left mating contact. The latter leads to the positive pole of the current duels: The time relay 34 actuates the normally closed contact 36, which has a drop-out delay and when the relay is de-energized by the spring 38 in Is held in the closed position. The contacts 35 and 36 are in the circuit of the electromagnet 17th

The operation of the system will now be described, on the assumption that according to the representation, according to FIG. In this case, the contact 36 in the circuit of the electromagnet is of no importance, and for the sake of simplicity it is initially regarded as not present. The starting point is the central position of the contact arm 23 in the control unit, which corresponds to point 7 of the tank water curve according to FIG. The relays 26 and 27 are then de-energized and the associated contacts 28 and 29 have dropped out. At point 7 the tank water movement has not yet come to rest; the contact arm 31 of the Woltman wing thus makes contact with the segment 32, whereby the relay 33 is energized and the contact lever of the changeover contact 35 is pulled to the left. The circuit of the -Elektromagneten is connected to the negative pole as well as via the left mating contact of 35 to the positive pole of the power source and is energized. The flap is thus open, as it must also be the case, because the tank water movement has not yet come to rest. In the meantime the contact arm 23 has run into the segment 24 and the relay a6 is energized. The associated contact 28 has a pick-up delay of the amount and therefore does not respond for the time being. Likewise, because the relay 27 is de-energized, the coil clock 29 continues to drop. At point 2 the tank water speed (dead center) and thus the contact 31, 32 is interrupted. The relay 33 is de-energized and the contact arm of the changeover contact 35 is placed to the right by the spring 37. Now the circuit of the electromagnet is interrupted because the contact 28 is still open because of its pick-up delay. The armature 18 of the electromagnet falls off and the flap 16 is moved into its closed position. At point 3 the delay time of relay 26 has expired and contact at 28 is made. The electromagnet is again energized, the flap opens; and the water flows from one tank to the other during the time corresponding to curve 3-4. As soon as the water begins to flow, the contact arm 31 runs onto the seriment 32, and the changeover contact 35 is placed to the left by the relay 33. However, since the left mating contact is on the positive pole of the power source, this will not cause any power interruption. At point 9 of curve b, contact arm 23 has returned to its central position. The relay 26 is de-energized at this moment and the contact 28 is interrupted. However, the electromagnet is not energized again until the tank water speed o, that is at point q., Because it is only at this moment that the changeover contact 35 is placed to the right; the flap is thus at point q. closed.

For the other half of the oscillation, if the contact arm 23 runs onto the segment 25, the same conditions result, since the contact arrangement of the control unit symmetrically and the contact device of the Woltman wing of is independent of the direction of flow.

The contact 36 has no meaning for the operational case just considered, however, even by its presence, it never interferes with the correct control. if the changeover contact 35 is on the right = contact 36 is closed; becomes the changeover contact 35 placed to the left, the contact 36 drops with a delay, but that calls, as can easily be seen, no disturbance emerges.

In contrast, the contact 36 is important in the event that the tank water according to FIG. 2, its dead center already before the time relays 26 are switched on and reached 27. It is assumed that the tank water is shortly before its Reversal points are located. The contact arm 23 then still has its middle position not reached, it is still about on the contact segment 25 and oscillates clockwise. Then the relay 27 is energized, so the contact 29 is closed. Furthermore, the relays 33 and 34 are excited by the contact -31, 32; the contact 36 is therefore interrupted, and the changeover contact 35 is on the left, so that the electromagnet 17 is energized and the flap 16 is open. At the moment of the reversal of movement of the tank water, so in point 2, the contact 31, 32 is interrupted, and the Changeover contact 35 is immediately pulled to the right by the spring 37. Because the contact 29 is still closed (the contact arm 23 has not yet reached its central position), the electromagnet 17 would still be energized if the contact 36 was also closed were. The associated relay 34th is, however, a timing relay with drop-out delay of the contact. So when the tank water speed o is reached (Point 2), then the contact 36 does not drop immediately, namely its delay time chosen so that it remains attracted, i.e. open, until the Time between points 2 and 7 is bridged. So if the tank water speed o is reached, the circuit of the electromagnet is immediately de-energized and the Flap 16 closed.

At point 7, the contact arm 23 goes through its central position. Now will the relay 27 de-energized, and the contact 29 drops immediately. Immediately after Passage of the contact arm 29 through its middle position, the relay 28 is energized, but because of the pick-up delay, the associated contact 28 remains for the time being opened. So the circuit of the electromagnet is now at another point interrupted, and the flap 16 remains in its closed position.

The drop-out delay of the contact 36 is approximately that of the route 2-1o (Fig. 2) corresponding time. - If contact is lost after this time has elapsed, the current interruption thus ceases, the electromagnet 17 can still not be excited because the contacts 28 and 29 are open. Only in point 3 is the delay time t2 "of relay 26 expired, whereupon contact 28 closes. The magnet is excited and opened the door.

The further mode of operation of the system is taking into account the Comments on the first operational case are easy to overlook. Experience has shown that they lie the points: 2 and 7 are never very far apart in time, so that. the fall time of the relay 34 can easily always be selected so that the time between the switching points 2 and 7 can be bridged with certainty.

If a phase regulator is not used for the control device, then an ordinary pendulum or rotary pendulum can serve as the control device. the The circuit shown in FIG. 3 is also readily available for such a control device to use. The contact arm 23 then only needs according to the pendulum swings to be moved. Its central position with respect to the contacts 24 1 and 25 corresponds the zero crossing of the pendulum. So it is every time the pendulum crosses zero Contact made and one of the two timing relays 26 and 27 switched on. One can assume that i is always the point in time for the reversal of movement of the tank water before the contact is made by the control unit, so that the operating case after Fig. 2 is present.

When arranging the shut-off device 16 in the water channel 1 ¢ can Control can be performed in the same way, and the result is the same Advantages as with the arrangement in the air duct 15. Another advantage according to the invention compared to the previously used control method is still in this case in that (read in Water channel arranged shut-off device when closing is not exposed to the risk of water hammer.

Instead of the Woltman wing, i can also use an ordinary pendulum flap serve to display the state of movement of the tank water. Fig. 4 shows a appropriate design of such a pendulum flap. In the water connection channel i ¢ the pendulum flap4o is rotatably suspended under the influence of its own weight always strives to occupy the vertical position. A sits on its axis of rotation Lever q. I, which works as a contact arm with the contact segments 42 and 43. At the tank water speed o the contact arm is in its middle position, the contact is therefore interrupted, while with an existing tank water flow ever in the direction of which the contact arm runs onto segment 42 or 43. The mode of action and circuitry is the same as in the Woltman wing of FIG and 3.4 just need to be connected to both segments 42 and 43 at the same time will.

Except for the deflection of the contact arm caused by the water flow 41 an additional deflection is caused by the weight of the flap; when the ship has a static lean. Contact is then made when the tank water is standing still, which of course must be avoided; the contact arm 41 may only leave its central position under the influence of the water current. In order to eliminate the disruptive influence of gravity, therefore, according to further Invention proposed that the pendulum flap by springs q. ¢ and ¢ 5 to their the tank water speed o to tie the appropriate zero position. The spring force is to be dimensioned so strong that that when the ship is tilted, the weight of the flap is balanced. on the other hand the spring force must not be too strong, so that the flap does not only start when it is strong Flow, but immediately after the reversal of movement of the tank water deflects. By Appropriate design of the flap and execution in light metal can be this Reach the condition without further ado.

Claims (3)

PATENT CLAIM: i. Tank stabilization system for ships in which the tank fluid movement is only caused by the ship's vibrations to be damped caused and controlled by a locking device, each at Reaching the largest liquid level difference closed and during passage of the ship is opened by its central position or a little later, according to the patent 63o637, with inevitable control of the closing time, characterized in that that the command for holding the tank liquid directly from a die Tank liquid movement indicating device is derived. . 2. Tank stabilization system according to claim i, characterized in that the one indicating the tank liquid movement Device consists of a pendulum flap arranged in the liquid channel. 3. Tank stabilization system according to An = claim 2, characterized in that the pendulum flap by springs to their zero position corresponding to the tank liquid velocity zero tied up and the spring force is so strong that it is used in inclined positions of the ship, the dead weight of the flap is balanced. q :: Tank stabilization system according to claim r, characterized in that the one indicating the tank liquid movement Device consists of a Woltman wing arranged in the liquid channel. 5. Tank stabilization system according to claim y, characterized in that the command for the release of the tank liquid movement at the moment of passage of the Ship through its central position from a device indicating this point in time, e.g. B. pendulum, gyro, is triggered and after one of the holding time of the tank liquid dependent delay time comes into effect. 6. Tank stabilization system according to Claim i, characterized in that the command for releasing the tank liquid movement at a certain point in time of each ship's half-cycle of one with one Phase regulator provided control device is triggered and after one of the hold time the tank liquid-dependent delay time comes into effect. 7. Tank stabilization system according to claim i, characterized in that at the moment of the command for the Holding the tank liquid a time relay is switched on, from which after When the delay time expires, the shut-off device opens.