RU2810008C1 - Device for purging internal volume of sunken ship - Google Patents

Abstract

FIELD: marine engineering.

SUBSTANCE: invention relates to technical devices used in raising sunken objects by restoring their buoyancy through displacing water with compressed air from their internal volumes. The device for purging the internal volume of a sunken ship is made in the form of a U-shaped pipe welded to the bottom of the cover with an opening and is designed to be hermetically installed on a cut-out in the upper part of the structure of the purged internal volume, the free end of which is designed to be discharged into the upper part of the purged internal volume and with the possibility of placing along the length of the blown internal volume closer to the tip of the sunken object, which is raised first. EFFECT: ensuring the release of expanding air from the purged internal volumes when the external hydrostatic pressure drops.

1 cl, 2 dwg

Description

The invention relates to technical devices used in raising sunken objects by restoring their own buoyancy by displacing water with compressed air from their internal volumes. Lifting technology involves the use of various types of devices that ensure the release of excess air from purged internal volumes (compartments), which expands during the ascent of a sunken object being lifted due to a drop in external hydrostatic pressure.

Known are squeezing pipes 13 (Fig. 1), installed in the purged compartments 4 of a sunken object, through which water 14 is displaced when compressed air 2 is injected [1, 2]. The pipe, when the compartment is completely purged and the water-air interface 16 passes along its lower end, ensures the discharge of the excess volume of expanding air, which is formed when the external hydrostatic pressure drops.

In not completely purged compartments, the discharge of expanding air through the squeeze pipe does not occur, since this is prevented by the hydraulic valve Ah, formed due to the immersion of the lower end of the squeeze pipe below the media interface level. At a small depth of immersion of the end of a pipe of sufficient flow area, the difference caused by a drop in external hydrostatic pressure can ensure the removal of a layer of water from the compartment, forming a hydraulic seal, and, as a result, the discharge of expanding air through the pipe. During significant immersion, air release, which prevents pressure build-up in the purged compartment, does not occur. For this reason, it is proposed to make the squeeze pipes movable and lower their ends deep into the compartments as they are purged. The disadvantage of movable squeeze pipes is the complexity of their design, the difficulty of controlling the degree of purging of the compartments, and the loss of time for moving the pipes, which increases the duration of work. The discrete movement of the squeeze pipes a priori creates a prerequisite for the formation of hydraulic valves, which, during dynamic ascent, can block the exit of expanding air, which will lead to a pressure surge inside the purged compartments, which can destroy them. To avoid destruction of the compartments, it is proposed to additionally install safety valves, for example, lever type, in their upper part [3]. The disadvantages of lever-type safety valves are the complexity of design, installation and configuration.

There are also known technical devices that protect purged steel ship-lifting pontoons from destruction during rapid ascent, called appendixes. A description of appendices and the theory of calculating their flow area are presented in the specialized literature [4]. They are hollow vertical pipes installed inside the pontoon compartments, the lower end of which is welded into the bottom of the pontoon above the hole, and the upper end is brought out to its ceiling. When blowing the pontoon, compressed air accumulates in the compartments and replaces the water in them that comes out through the open lower necks. The water level in the compartments and in the appendix decreases simultaneously. When a pontoon that is not fully inflated floats up, a pressure drop occurs. Water from the pontoon does not have time to exit through the necks, which have a limited flow area, and clear the passage for discharging the excess volume of expanding air. In the appendixes, the amount of water is relatively small, which allows it to come out almost instantly, freeing up the passage for air to escape. The location of the appendices on the bottom of the pontoon does not interfere with their unhindered operation, since when the sunken object raised by the pontoons surfaces, the pontoons are in the water column. Appendices are an integral part of the pontoon design and are mounted on them during construction. The disadvantage of appendices installed in the lower part of the ventilated compartments of a sunken object is the complexity of installation, requiring divers to penetrate into the compartments and create cutouts in the bottom, which is in contact with the seabed. If there is silt and water-saturated soil at the bottom, it inevitably penetrates into the compartments intended for purging, which leads to a decrease in the purged volume, an increase in the lifting weight of the sunken object being lifted and the pull-out resistance of the soil, and also prevents the attachment of the appendix in the compartment. Thus, the use of appendixes, effective and proven in practice when using ship-lifting pontoons, to discharge excess volume of expanding air from the compartments of a sunken object raised by the blowing method, is not possible.

The objective of the invention is to eliminate the above disadvantages and use the principle of operation of appendices in relation to the purged internal volumes (compartments) of a sunken object (ship), raised by a method of restoring its own buoyancy by displacing water with compressed air.

The problem is solved by manufacturing an appendix (Fig. 1 and 2) in the form of a hollow U-shaped pipe 6, open at both ends, installed inside a closed purged volume 4 through a cutout 12 in its upper part so that one end communicates with the environment, and the second end was located inside the ventilated compartment under its ceiling. The elbow of the pipe should be below the ends of the squeeze pipes 13. When the pressure 1 increases inside the purged volume when it is blown with compressed air 2 through the injection hose 3, water 15 comes out through the lower ends of the squeeze pipes 14. When the air is completely purged through them, air begins to escape, and in U the -shaped pipe is set to a level equal to the water level in volume 16. When the sunken object being lifted rises to the surface, which began with incomplete purging of the internal volumes, when the exit of expanding air 5 through the squeeze pipes is prevented by the formed water seal Δh, water is almost instantly squeezed out of the U-shaped pipe, which frees the outlet for expanding air 18 and prevents the destruction of the purged internal volumes due to pressure drop 1 caused by a drop in external hydrostatic pressure. The flow section of a U-shaped pipe is calculated according to known theoretical dependencies set out in the specialized literature by analogy with the calculation of appendices [4].

The technology for using an appendix-type device that protects the purged internal volumes (compartments) of a sunken object (ship) being lifted from destruction when external hydrostatic pressure drops does not differ from the technology for installing squeeze pipes 13 and involves creating a cutout 12 in the upper part of the volume (compartment), into which install a sealed cover 10 using welding or clamping bolts 9 with a sealing gasket 8, to the lower part of which, closing the through hole, a U-shaped pipe 6 is secured using brackets 11. The structure of the pipe is rigid, if necessary, tightened with bandages 7. Places for installing safety devices are selected on free surfaces so that they are closer to the lifted end of the sunken object, and the creation of cutouts does not weaken the structural strength of the purged internal volume (compartment).

New distinctive features are the manufacture of the appendix in the form of a U-shaped pipe and its installation not in the lower, but in the upper part of the purged internal volume (compartment).

These distinctive features provide:

- speed and, as a result, high efficiency of the safety device;

- simplification of the design of the safety device compared to a lever-type safety valve or a movable squeeze pipe;

- installation of a safety device in the upper part of the blown internal volume (compartment) without the need to perform installation work inside it and open the bottom, which creates a threat of soil penetration into the blown internal volume (compartment), making it difficult not only to install the safety device itself, but also to lift the sunken object into in general due to an increase in its lifting weight and tear-off resistance, as well as a decrease in the blown volume. The economic effect of introducing an appendix-type device that protects the purged internal volumes (compartments) of a raised sunken object from destruction when the external hydrostatic pressure drops (safety U-shaped pipe) is to prevent damage to the purged internal volumes (compartments), which requires costs for their repair or changes in lifting technology, leading to losses in the results of previously performed work, the costs of which become unjustified. The cost of installing a safety pipe is equal to the cost of installing a lever safety valve, and the complexity of the design of the safety pipe and, as a result, the cost of its manufacture is less than that of the valve.

Literature

1. Patent of the Russian Federation dated April 28, 2020 No. 2720299, “Method for raising a sunken object.”

2. Patent of the Russian Federation dated 09/06/2022 No. 2779337, “Method of lifting a sunken object using the blowing method with automatic stabilization by trim and ascent speed.”

3. Patent of the Russian Federation dated September 21, 2022 No. 2780362, “Lever-type safety valve for relieving excess pressure from the purged compartments of a raised sunken object.”

4. Ship-lifting pontoons. Ed. engineer-captain 1st rank S.R. Kravchenko. - M.: UVMINKVMF, 1946. - P. 61, 108-118.

Claims (1)

A device for purging the internal volume of a sunken ship, characterized in that it is made in the form of a U-shaped pipe welded to the bottom of the cover with a hole and is designed to be hermetically installed on a cutout in the upper part of the structure of the purged internal volume, the free end of which is configured to leading to the upper part of the blown internal volume and with the possibility of placement along the length of the blown internal volume closer to the tip of the sunken object, which is lifted first.