DE300364C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

PATENT LETTERING

- te 300364 CLASS 65 b. GROUP

SIEMENS-SCHUCKERTWERKE G. μ. β.Ή. in SIEMENSSTADT B.BERLIN.

To operate floating docks, their cavities have been divided into individual chambers, each of which can be pumped (drained) empty. To now the individual chambers To empty, centrifugal pumps (bilge pumps) are used, their delivery rate is regulated by gate valves in the pressure line of the pumps. The bilge pumps are usually driven by individual electric motors, their regulating devices are summarized in the cab of the floating dock. However, the use of these motors has many disadvantages Respect with itself. Starting the engines

^X 5 from the driver's cab and engine requires electrical lines with a large cross-section, since it is a matter of regulating starting currents, which are considerable given the high performance of the individual bilge pumps. In the case of large floating docks up to a length of 240 m, these control lines cause significant costs. In addition, the motors with collector or slip rings are expensive and require maintenance.

Three-phase motors with short-circuit armature can be used for the individual operation of bilge pumps cannot be used without further ado, because the large ones are required for the pump drive Power your starting current is much too high. That. Starting with a star-delta connection is also not possible because the starter switch has large currents "to interrupt." have, so wear out quickly.

The invention solves the problem of using emptying of the individual docking chambers of three-phase motors with short-circuit armatures of the normal type, thereby considerably simplifying the process and lower the cost of the dock in terms of facility and operation. The task is solved in that each bilge pump is driven by a three-phase motor with a short-circuit armature, these motors in groups summarized by a three-phase generator by gradually increasing its terminal voltage to the correct one RPM are brought. It is through this establishment that the peculiarities become of the dock operation with centrifugal pumps used very favorably. The disadvantages long lines and starting devices for heavy current are eliminated. Since starting losses are avoided, the efficiency of the system is very high. The investment and operating costs are much smaller than the docking facilities known to date. But the whole system is very simple, reliable and clear.

To operate the dock, it depends on the dimensions and weight distribution of the _6o docked vehicle necessary, individual docking chambers more, others less. This is achieved with the new arrangement in that all motors are permanently attached to their Generators remain connected, but that the delivery rate of the connected with them

which pumps is regulated in a known manner by adjusting the gate valve in the pressure line of the pump in question. In the drawing, an exemplary embodiment of the invention is shown schematically. Fig. Ι shows a cross section of the floating dock, Fig. 2 is a view of the dock seen from above.

In its lower part, the dock contains, for example, two rows of chambers a and b, which in FIG. 2 are delimited by the outer boundary of the dock and by the dashed lines. In each chamber there is a centrifugal pump c which is driven by a three-phase motor e by means of the shaft d, which is set up in a higher room of the dock. In the example shown, the motors belonging to the pumps in the right half of the dock are combined in a group, as are the motors in the other half. Its stators are permanently connected in parallel to the power generator g, which is driven by the driving machine f and whose excitation current is supplied by a DC exciter h coupled to it. The controller i of the exciter h is set up in the driver's cab k of the dock.

The device works as follows:

To operate the dock, the power generator g is driven by the driving machine / - The terminal voltage on the power generator or on the motors is initially zero, since the excitation is initially switched off. At the gradual. When the excitation is switched on, the terminal voltage increases and the motors start up. The shut-off valves of the pumps are closed when starting and the load on the drive motors is therefore relatively low. After all, it is. . cos y of the three-phase generator is unfavorable because it has to deliver a very high wattless current in order to saturate the rotors when starting up. The three-phase generator must therefore be sufficiently dimensioned with this arrangement. When the generator is fully excited and the pump's gate valve is closed, the load on the motors c is low and increases when the individual valves are opened up to the normal value.

The advantage of the arrangement described is that there is only one starter in the driver's cab needs to be arranged for low power and only lead low power lines to the three-phase generator.

The machine set /, g, h can be set up in any location; the machines can be on the dock itself, on a ship or on land.

If you do not want to measure the power generator g in abundance, you can also make the arrangement so that nothing is changed in the setting of the field controller of the power generator, but that the speed of the drive machine is changed from zero to a maximum value. * This is of course particularly easy if this prime mover is an electric motor. After all, this arrangement requires the engine to be started from the driver's cab using a control line for high voltage current or by remote control (using a self-starter, which makes the system more complicated. grows with the speed '(exciter), is meaningless.

Claims (1)

80 patent claim: Device for emptying the individual chambers of floating docks, whereby the delivery rate of the individual centrifugal pumps through gate valves in the Pressure line of the pumps is regulated, characterized in that each bilge pump is driven by a three-phase motor with a short-circuit armature, and these motors, combined in groups, from a three-phase generator by gradually increasing its terminal voltage "to. the correct. number of revolutions to be brought. 1 sheet of drawings.