Abstract

A method of cooling a boil-off gas (BOG) stream from a liquefied gas tank comprising at least the step of heat exchanging the BOG stream with a first refrigerant in a heat exchanger, the heat exchanger having an entry port and a warmer exit port, and comprising at least the steps of: (a) passing the first refrigerant into the entry port of the heat exchanger and into a first zone of the heat exchanger to exchange heat with the BOG stream, to provide a first warmer refrigerant stream; (b) withdrawing the first warmer refrigerant stream from the heat exchanger at an intermediate exit port between the entry port and the warmer exit port; (c) passing the first warmer refrigerant stream through an entry port located in a second zone of the heat exchanger that is warmer than the first zone (d) passing an oil-containing refrigerant stream through an entry port located in a second zone of the heat exchanger that is warmer than the first zone; (e) mixing the first warmer refrigerant stream and the oil-containing stream in the heat-exchanger to form a combined refrigerant stream; and (f) passing the combined refrigerant stream out of the heat exchanger through the warmer exit port.

IPC Classes  ?

• F25J 1/00 - Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
• F25J 1/02 - Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen

Abstract

A method of cooling a boil off gas stream (01) from a liquefied cargo having a boiling point of greater than -110 °C when measured at 1 atmosphere in a liquefied cargo tank (50) in a floating transportation vessel, said method comprising at least the steps of: compressing a boil off gas stream (01) from said liquefied cargo in two or more stages of compression comprising at least a first compression stage (65) and a final compression stage (75) to provide a compressed BOG discharge stream (06), wherein said first compression stage (65) has a first stage suction pressure and said final compression stage (75) has a final stage suction pressure; cooling the compressed BOG discharge stream (06) against one or more first coolant streams (202, 302) to provide a first cooled compressed BOG stream (08); providing a gaseous vent stream (51) from the first cooled compressed BOG stream (08); cooling the first cooled compressed BOG stream (08) against a second coolant stream (33) to provide a second cooled compressed BOG stream (35); expanding a portion of the second cooled compressed BOG stream (35) to the first stage suction pressure or below to provide a first expanded cooled BOG stream (33); using the first expanded cooled BOG stream (33) as the second coolant stream to provide a first expanded heated BOG stream (38); and cooling the gaseous vent stream (51) against the second coolant stream (33) to provide a cooled vent stream (53), wherein cooling of the first cooled compressed BOG stream (08) and cooling of the gaseous vent stream (51) occurs in a heat exchanger located adjacent to the liquefied cargo tank (50).

IPC Classes  ?

• F25J 1/00 - Processes or apparatus for liquefying or solidifying gases or gaseous mixtures

Abstract

A method of cooling a boil off gas stream from a liquefied cargo (50a) in a floating transportation vessel is described. The method comprises: compressing a boil off gas stream in two or more stages of compression to provide a compressed BOG discharge stream; cooling the compressed BOG discharge stream against one or more first coolant streams to provide a first cooled compressed BOG stream; cooling the first cooled compressed BOG stream against at least one second coolant stream to provide a second cooled compressed BOG stream; providing a vessel fuel stream from the liquefied cargo; using the vessel fuel stream as a coolant stream to cool either the compressed BOG discharge stream, or the first cooled compressed BOG stream, or both said streams.

IPC Classes  ?

• F25J 1/00 - Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
• F25J 1/02 - Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen

Abstract

There is provided a method of cooling a boil-off gas (BOG) stream from a liquefied gas tank using a single mixed refrigerant (SMR) comprising at least the step of heat exchanging the BOG stream with the SMR in a liquefaction heat exchanger system to provide a cooled BOG stream, wherein the SMR is provided in an SMR recirculating system comprising at least the steps of: (a) compressing the SMR using at least one centrifugal compressor to provide a post-compression SMR stream; (b) passing the post-compression SMR stream into the liquefaction heat exchanger system to cool the post-compression SMR stream and provide a cooled first SMR vapour stream; (c) withdrawing the cooled first SMR vapour stream from the liquefaction heat exchanger system; (d) separating the cooled first SMR vapour stream to provide a liquid-phase SMR stream and a light SMR vapour stream; (e) passing the light SMR vapour stream through the liquefaction heat exchanger system to provide a condensed SMR stream; and (f) expanding the condensed SMR stream to provide an expanded Iowest-temperature SMR stream to pass through the liquefaction heat exchanger system for heat exchange against the BOG stream.

IPC Classes  ?

• F25J 1/00 - Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
• F25J 1/02 - Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen

Abstract

A method of cooling a boil-off gas (BOG) stream from a liquefied gas tank comprising at least the step of heat exchanging the BOG stream with a first refrigerant in a heat exchanger, the heat exchanger having an entry port and a warmer exit port, and comprising at least the steps of: (a) passing the first refrigerant into the entry port of the heat exchanger and into a first zone of the heat exchanger to exchange heat with the BOG stream, to provide a first warmer refrigerant stream; (b) withdrawing the first warmer refrigerant stream from the heat exchanger at an intermediate exit port between the entry port and the warmer exit port; (c) admixing the first warmer refrigerant stream with an oil-containing refrigerant stream to provide a combined refrigerant stream; (d) passing the combined refrigerant stream into the heat exchanger through an entry port located in a second zone of the heat exchanger that is warmer than the first zone; (e) passing the combined refrigerant stream out of the heat exchanger through the warmer exit port. The present invention is a modification of a refrigerant cycle for BOG cooling, and LNG re-liquefaction in particular, that allows the use of a cost-efficient oil-injected screw compressor in the refrigerant system. The present invention is also able to accommodate the possibility of different flows or flow rates of the first refrigerant stream and the oil-containing refrigerant stream, such that there is reduced or no concern by the user of the process in relation to possible oil freezing and clogging of the heat exchanger caused by variation of the flow or flow rate of the oil-containing refrigerant stream.

IPC Classes  ?

• F25J 1/00 - Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
• F25J 1/02 - Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen
• F25B 1/047 - Compression machines, plants or systems with non-reversible cycle with compressor of rotary type of screw type
• F25B 31/00 - Compressor arrangements
• F25B 43/02 - Arrangements for separating or purifying gases or liquidsArrangements for vaporising the residuum of liquid refrigerant, e.g. by heat for separating lubricants from the refrigerant

Abstract

The present invention is a modification of a typical single mixed refrigerant (SMR) cycle for LNG re-liquefaction in particular, that allows the use of a cost-efficient oil-injected screw compressor in the mixed refrigerant system. In comparison with the typical arrangement, the present innovation allows for reduced complexity, fewer pieces of equipment, and reduced capital cost. There is shown a method of cooling a boil-off gas (BOG) stream from a liquefied gas tank using a single mixed refrigerant (SMR) comprising at least the step of heat exchanging the BOG stream with the SMR in a liquefaction heat exchanger system to provide a cooled BOG stream, wherein the SMR is provided in an SMR recirculating system comprising at least the steps of: (a) compressing the SMR using at least one oil-injected screw compressor to provide a post-compression SMR stream; (b) separating the post-compression SMR stream to provide an oil-based stream and a first SMR vapour stream; (c) passing the first SMR vapour stream into the liquefaction heat exchanger system to cool the first SMR vapour stream and provide a cooled first SMR vapour stream; (d) withdrawing the cooled first SMR vapour stream from the liquefaction heat exchanger system; (e) separating the cooled first SMR vapour stream to provide a liquid-phase SMR stream and an oil-free SMR vapour stream; (f) passing the oil-free SMR vapour stream through the liquefaction heat exchanger system to provide a condensed SMR stream; and (g) expanding the condensed SMR stream to provide an expanded lowest-temperature SMR stream to pass through the liquefaction heat exchanger system for heat exchange against the BOG stream.

IPC Classes  ?

• F25J 1/00 - Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
• F25J 1/02 - Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen

Abstract

The present invention relates to the use of compressed volatile organic compounds wholly or partly as a source of blanket gas for use in oil storage tanks, and methods and apparatus of providing same This includes a method of recovering and using VOC from one or more oil storage tanks comprising recovering, compressing and separating VOC from an oil storage tank, compressing the separated uncondensed VOC to provide a compressed VOC stream, and then heating and reducing at least a portion of the compressed VOC stream to provide a decompressed VOC stream for use as blanket gas in an oil storage tank. The present invention is able to prevent or substantially reduce reabsorption of captured VOC into stored oil. This also requires less (and possibly no) addition of extra inert gas during the oil discharge, and the next oil loading into the oil storage tank starts with a tank atmosphere that is very high in hydrocarbon content, thereby preventing formation of additional VOC during the next oil loading.

IPC Classes  ?

• B63B 27/24 - Arrangement of ship-based loading or unloading equipment for cargo or passengers of pipe-lines
• B01D 5/00 - Condensation of vapoursRecovering volatile solvents by condensation
• F17C 6/00 - Methods or apparatus for filling vessels not under pressure with liquefied or solidified gases

Abstract

The present invention has been developed to improve the way a payload support platform, such as a mole, is driven between one site and another, particularly when the second site is the interior of a Lift which interfaces with a Pallet Handling System (PHS) of a ship. In a first aspect the invention proposes that the driving means which drives the payload support platform along a rail (10) is also used to move that rail (10) relative to the payload support platform and a support rail (22) so that the position of the rail can be changed during the movement of the payload support platform between one site and another. The payload support platform is lockable to the support rail (22), such that the force which drives the payload support platform along the rail (10) changes to driving the rail (10) relative to the support rail (22). In a second independent aspect of the invention the movable rail (10) is mounted in the gap between ends of fixed rails (62, 82) and is movable along a support rail (22) on which it is mounted between a position in which one end of the movable rail (10) is adjacent an end of one of the fixed rails (62, 82) to another position in which the other end of the movable rail (10) is adjacent the end of the other fixed rail (62,82).

IPC Classes  ?

• B66F 13/00 - Common constructional features or accessories
• B63B 25/22 - Load-accommodating arrangements, e.g. stowing or trimmingVessels characterised thereby for palletised articles
• B65G 25/04 - Conveyors comprising a cyclically-moving, e.g. reciprocating, carrier or impeller which is disengaged from the load during the return part of its movement the carrier or impeller having identical forward and return paths of movement, e.g. reciprocating conveyors
• B25B 31/00 - Hand tools for applying fasteners
• B25B 27/08 - Hand tools or bench devices, specially adapted for fitting together or separating parts or objects whether or not involving some deformation, not otherwise provided for for connecting objects by press fit or detaching same inserting or withdrawing cotter pins

Abstract

b), in which the center of mass is closer to the center of buoyancy, to improve towing stability in the water, thereby allowing the buoy to be towed with its long axis substantially aligned with the direction of motion, thereby reducing wake/plume in the water.

IPC Classes  ?

• B63B 22/18 - Buoys having means to control attitude or position, e.g. reaction surfaces or tether
• B63G 8/40 - Rescue equipment for personnel

Abstract

A payload deployment system for a vessel, such as a submarine, which includes a cable extending between a piston in a piston tube and an ejection element in an ejection tube, wherein the ejection tube is suitable for holding the payload, such as a torpedo. The system is arranged such that movement of the piston in the piston tube causes movement of the cable which, in turn, exerts a force on the ejection element to move it in the ejection tube to eject the payload from the ejection tube.

IPC Classes  ?

• F41F 3/08 - Rocket or torpedo launchers for marine torpedoes

Abstract

A submarine (1) has an assembly (3) for deploying a life raft (5), the assembly (3) being located in a well (7) formed outside the submarine's pressure hull (11). The assembly includes a pressure vessel (4) for storing the life raft (5) in a pressurized state. To deploy underwater, a lid (71) covering an opening to the well (7) is released to permit the assembly (3), which is buoyant, to ascend towards the water surface. A sensor (43) determines proximity to the water surface, whereby a pneumatic ram (42) in the pressure vessel is activated to eject the life raft (5) from the pressure vessel (4).

IPC Classes  ?

• B63G 8/41 - Capsules, chambers, water-tight boats, or the like, detachable from the submarine
• B63C 9/02 - Lifeboats, life-rafts or the like, specially adapted for life-saving
• B63C 9/22 - Devices for holding or launching life-buoys, inflatable life-rafts, or other floatable life-saving equipment
• B63C 9/23 - Containers for inflatable life-saving equipment

Abstract

A platform for the aerial delivery of payloads into aquatic environments has a staged v cross-section formed by two walls extending from an end part. The portions of the two walls adjacent to the end part diverge from it at an angle θ and, together with the end part, form the tip of the platform. The remaining portions of the two walls, remote from the end part, form the body of the platform, and diverge at an angle φ that is greater than the angle θ. When the platform is deployed onto the surface of a fluid, it initially experiences a period of low deceleration as the tip penetrates the surface, followed by a period of higher deceleration, as the body contacts the surface.

IPC Classes  ?

• B64D 1/14 - Absorbing landing shocks