Abstract:
In a plant for the production of fuel gas from boil-off and from liquefied gas with the aid of a combined heat exchanger (9), a compressor (4) is placed upstream of the heat exchanger in the gas line carrying boil-off. Compressed boil-off and liquefied gas pass in heat exchange in a combined heat exchanger (9) which has separate flow banks (7, 8) for liquefied gas and boil-off, respectively. From the combined heat exchanger (9), the two volumes of gas pass in a mixture to a consumer through a pipeline (5).
Abstract:
An apparatus that provides for withdrawal of the liquid contents from a closed container (14) independent of the spatial orientation thereof, is described. The liquid withdrawal apparatus includes flexible withdrawal conduits (58) disposed inside the container and in fluid flow communication with external heat exchangers (144, 146). The heat exchangers serve to transfer heat to the withdrawn liquid to thereby provide a breathable gas mixture. The pick-up end of the withdrawal conduits (58) are weighted to ensure liquid withdrawal during changes in the orientation of the container while the outlet end of the tubes (62) communicates through septa (140, 142) that ensure there is little to no communication of pressure between the inside of the container and the heat exchangers, other than the fluid flow communication path provided by the conduits themselves. A pressure differential between the inside of the container and the external heat exchangers, normally brought about by an inhalation event of the user, provides the motive force for withdrawing the liquid contents from the container through the conduits.
Abstract:
A heat exchanger device, comprising a first heat exchanger for evaporation of liquid natural gas (LNG), and a second heat exchanger for superheating of gaseous natural gas (NG). The heat exchangers (1) are arranged for heating these fluids by means of a heating medium and have an outlet which is connected to a mixing device (20) for mixing the heated fluids with the corresponding unheated fluids. According to the invention the heat exchangers (1) comprise a common housing (2), in which there are provided separate passages (7, 8) for the fluids. The mixing device (20) constitutes a unit together with the housing (2) and has a single mixing chamber (23) with one single fluid outlet (30). In separate passages (7, 8) there are provided valves (10, 26) and (13, 28) respectively for the supply of LNG or NG in the housing (1) and the mixing chamber (23).
Abstract:
A method of draining a tank that has been containing liquid gas, and a plant for use in such draining. After draining of the major part of the tank contents, but while residual contents of gas are present in vapourized state in the tank, the residual contents are conveyed for exchanging heat directly or indirectly with cold nitrogen. Nitrogen is vapourized and heated and conveyed to the tank, while the residual gas is cooled and condensed and conveyed to a collector tank. The plant comprises a heat exchange system (4, 8; 30, 39) connected to the supply (2) of nitrogen, and residual gas is forced from the tank to be drained and through the heat exchange system (4, 8) in order to cause vapourization and heating of nitrogen to be conveyed to the tank, in such a manner that the residual gas from the tank condenses, whereby a collector container (3) is connected for receiving condensed residual gas. In order to prevent that the residual gas freezes during the exchange of heat a cooling agent can be used which causes vapourization and heating of the nitrogen and which also is used for condensing the residual gas, without cooling the latter to below its freezing point.
Abstract:
A natural gas vehicle fuel delivery system regulates the pressure of LNG which is vaporized and delivered to an engine. The system employs dual regulator valves (34/31 and 32/33) responsive to the gas phase pressure of the storage tank (10A/10B) to either directly couple vapor produced from a heat exchanger (61/63) to an engine combustion system, or to divert that vapor through another heat exchanger (62A/62B) contained within the tank (10A/10B) itself. This additional heat exchanger (62A/62B) maintains the pressure within the tank (10A/10B) at the desired level despite heavy fuel demands of the engine. The system functions independent of liquid level in the storage tank (10A/10B). When multiple LNG storage tanks (10A, 10B) are used, they are coupled in parallel so that they both produce gas and are concurrently regulated in the gas phase portion. A pressure initializing structure and process are also provided.
Abstract:
In a system for the provision of fuel gas from decoction (boil-off) from liquefied petroleum gas and optionally gas produced by the evaporation of the liquefied gas, there is used a combined heat exchanger (13), wherein boil-off and liquefied petroleum gas are heated. Via a common mixing chamber (16) in the combined heat exchanger a combined stream of overheated gas may be supplied to a compressor (18). The compressor (18) may advantageously be of a normal type since its suction temperature will be sufficiently high to allow this, precisely as a result of the heating and evaporation, respectively, in the combined heat exchanger.
Abstract:
A process and device are disclosed for evaporating liquid gas in an evaporator with temperature control (16-23) of the evaporator heating means (9) and a safety device that cuts off the liquid gas supply (3, 4) or the evaporator heating means (18) when the temperature goes beyond a maximum temperature or falls below a minimum temperature. An additional safety device controlled by temperature measuring elements (26, 35 or 38) cuts off the liquid supply (3, 4) or the evaporator heating means when the temperature goes beyond a safe temperature set higher than the maximum temperature or falls below a low temperature set lower than the minimum temperature.
Abstract:
A cryogenic liquid delivery system includes a storage tank (12) holding a quantity of a cryogenic liquid such as liquid oyygen (13) and a vapor space (11). A compound, two-part dip tube includes an inner liquid delivery tube (44) and an outer tube (20) which is sealed to allow liquid cryogen to be delivered to a vaporizer (18) only via the liquid delivery tube. The vaporizer (18) communicates with the vapor space (11) in the tank via an aperture (46) in the outer tube, above the level of the liquid cryogen and the seal (48).
Abstract:
A process and plant are disclosed for conveying high-pressure gas to a consumption site from a low-pressure liquefied gas supply reservoir. The objet of the invention is to dispense with high-pressure gas units such as gas cylinder sets and to improve liquefied gas transport by means of a high-pressure gas. Liquefied gas from the reservoir flows into at least one container having a size selected so that the time required to empty the recipient is shorter than the time required for thermal equilibrium to be reached in the container. The head space of the container is then filled with evaporated gas from an external evaporator until the liquefied gas may be supplied at the required high pressure to the consumption site. Every time the container is empty, it is filled again with liquefied gas. For that purpose, the container(s) must have a considerably smaller volume than the reservoir of liquefied gas. THis system is particularly suitable to generate supercritical, high-pressure gas.
Abstract:
The device is of the streaming type and comprises a bundle of tubes (1), preferably assembled in the form of panels and connected to inlet and outlet manifolds, on which a water stream flows. In order to achieve resistance to salt water corrosion, the device is made of AG4MC aluminium alloy and the cross section of each tube comprises two diametrically opposed outer ribs (2, 3), and inner ribs (5). It is preferably made by extrusion. Application to revaporization of natural gaz.