The present invention relates to a pump (15) for pumping a coolant (9) within a Dewar vessel (1) and to a corresponding Dewar vessel (1) for storing samples in a coolant (9). The Dewar vessel (1) comprises a thermally insulated reservoir (3) for the coolant (9) and a sample vessel (11) provided separately and arranged in the thermally insulated reservoir (3). The reservoir (3) is connected to the sample vessel (11) in such a way that the level of coolant (9) is constant in the sample vessel (11). Pump (15) may help in keeping the level of coolant (9) in the sample vessel (11) constant. For this purpose the pump (15) comprises a chamber (17) with an inlet (19) and an outlet (21), a closing element (23) and a pressure increasing device (25). Therein, the inlet (19) is connectable to the reservoir (3) and the outlet (21) is connectable to a sample vessel (11) of the Dewar vessel (1). The chamber (17) is adapted to fill with coolant (9) through the inlet (19) by gravity and the closing element (23) is adapted to automatically close the chamber (17) when it is full of coolant (9). The pressure increasing device (25) is adapted to increase the pressure within the chamber (17), after the chamber (17) is closed, until the coolant (9) is released through the outlet (21).

In a method for reheating an atmospheric vaporizer, a cryogenic liquid is vaporized by heat exchange with ambient air in the atmospheric vaporizer and to reheat the vaporizer, a gas is sent thereto at a temperature of at least 0 C., this gas originating from a cryogenic distillation air separation unit.

In a method for reheating an atmospheric vaporizer, a cryogenic liquid is vaporized by heat exchange with ambient air in the atmospheric vaporizer and to reheat the vaporizer, a gas is sent thereto at a temperature of at least 0 C., this gas originating from a cryogenic distillation air separation unit.

A vaporizer system includes a defrosting function along with the ability to convert liquefied gas to a use gas. The vaporizer system includes first and second vaporizers and piping that transfers fluid from an inlet port to an outlet port with a portion of the piping being between the first and second vaporizer. The system also includes a trim heater and a number of valves for regulating flow of the fluid through the transfer piping. The valves may be placed in a first configuration where vapor from the first vaporizer is heated and directed to the second vaporizer so that the second vaporizer is defrosted and a second configuration where vapor from the second vaporizer is heated and directed to the first vaporizer so that the first vaporizer is defrosted.

A vaporizer system includes a defrosting function along with the ability to convert liquefied gas to a use gas. The vaporizer system includes first and second vaporizers and piping that transfers fluid from an inlet port to an outlet port with a portion of the piping being between the first and second vaporizer. The system also includes a trim heater and a number of valves for regulating flow of the fluid through the transfer piping. The valves may be placed in a first configuration where vapor from the first vaporizer is heated and directed to the second vaporizer so that the second vaporizer is defrosted and a second configuration where vapor from the second vaporizer is heated and directed to the first vaporizer so that the first vaporizer is defrosted.

Disclosed is a BOG reliquefaction system. The BOG reliquefaction system includes: a compressor compressing BOG; a heat exchanger cooling the BOG compressed by the compressor through heat exchange using BOG not compressed by the compressor as a refrigerant; a pressure reducer disposed downstream of the heat exchanger and reducing a pressure of fluid cooled by the heat exchanger; and a second oil filter disposed downstream of the pressure reducer, wherein the compressor includes at least one oil-lubrication type cylinder and the second oil filter is a cryogenic oil filter.