Abstract: In a system for dispensing a cryogenic fluid, a bulk tank is configured to contain a supply of a cryogenic liquid. A sump is configured to receive cryogenic liquid from the bulk tank. A first positive-displacement pump is positioned within the sump and is configured to be submerged within and pump cryogenic liquid stored within the sump. A second positive-displacement pump is positioned within the sump and is configured to be submerged within and pump cryogenic liquid stored within the sump. A vaporizing heat exchanger is configured to receive and vaporize cryogenic liquid pumped from the first pump and/or the second pump.

Abstract: A pump for pumping a cryogenic liquid includes a pump housing defining an elongated cylinder. An elongated piston slides within the cylinder so that an intermediate fluid chamber, that is configured to receive an intermediate fluid, is defined within the cylinder adjacent to a first end of the piston and a fluid pumping chamber is defined within the cylinder adjacent to a second end of the piston. The fluid pumping chamber includes an inlet and an outlet. The pump housing is positioned within a sump. The sump is configured to receive and submerge a portion of the pump housing within the cryogenic liquid and to provide cryogenic liquid to the inlet of the pumping chamber for pumping. A sump jacket surrounds the sump so that a sump insulation space is defined therebetween. A pump jacket surrounds the pump housing so that a pump insulation space is defined therebetween.

Abstract: A cryogenic fuel tank system includes a fuel tank configured to contain a cryogenic liquid with a headspace above the cryogenic liquid configured to contain cryogenic vapor. A fuel cell converts cryogenic vapor from the headspace to electricity and water vapor. A vent valve directs excess cryogenic vapor from the headspace to the fuel cell when a pressure in the fuel tank exceeds a predetermined pressure level.

Abstract: A system for dispensing a cryogenic fluid includes a bulk tank configured to contain a supply of a cryogenic liquid, a first sump and a first liquid feed valve configured to direct liquid from the bulk tank to the first sump when in an open condition and to prevent transfer of liquid from the bulk tank to the first sump when in a closed condition. A first positive displacement pump is positioned within the first sump and configured to pump and be submerged in cryogenic liquid when the first sump contains cryogenic liquid above a predetermined liquid level within the first sump. A delivery line is in fluid communication with an outlet of the first positive displacement pump and is configured to direct cryogenic fluid from the first positive displacement pump to a use device when the first positive displacement pump is activated.

Abstract: A cryogenic fluid delivery system includes a pump having a pumping cylinder within which a sliding pumping piston is positioned. The pump also includes an actuating cylinder within which a sliding actuating piston is positioned and a supplemental linear actuator, such as a hydraulic cylinder. The pumping and actuating pistons and supplemental linear actuator are joined by connecting rods. A portion of the cryogenic liquid pumped from a storage tank is vaporized in a heat exchanger and introduced into the actuating cylinder to power the pump with the assistance of the supplemental linear actuator so that high pump discharge pressures may be obtained.

Abstract: A system dispenses both liquid natural gas (LNG) and compressed natural gas (CNG). A bulk tank contains a supply of LNG which is pumped to a smaller storage tank. After the storage tank is refilled, LNG from the bulk tank is pumped to a vaporizer so that CNG is produced. The CNG may be routed to the LNG in the storage tank to condition it. It is also used to recharge a pressurizing cylinder that is placed in communication with the head space of the storage tank when it is desired to rapidly dispense LNG to a vehicle. A bank of cascaded storage cylinders alternatively may receive CNG from the vaporizer for later dispensing through the system CNG dispenser. The CNG from the vaporizer may also be dispensed directly via the system CNG dispenser.

Abstract: A system for dispensing cryogenic liquid to a use device includes a bulk storage tank providing LNG to a sump containing a meter submerged in LNG. A temperature probe is also submerged in the LNG. A dispensing line is positioned between the meter and dispensing hose and includes a dispensing valve. A drain line bypasses the dispensing valve and features a check valve so that LNG trapped in the hose after dispensing is returned to the sump due to pressurization by ambient heat. A capacitance probe is submerged in the LNG in the sump and provides a dielectric that is compared by a microprocessor with the dielectric for pure methane at the same temperature to determine the purity of the LNG. An approximate linear relation between density and dielectric may be used to determine density and mass flow for the LNG from the measured dielectric.

Abstract: A system for dispensing cryogenic liquid to a use device includes a bulk storage tank providing LNG to a sump containing a meter submerged in LNG. A temperature probe is also submerged in the LNG. A dispensing line is positioned between the meter and dispensing hose and includes a dispensing valve. A drain line bypasses the dispensing valve and features a check valve so that LNG trapped in the hose after dispensing is returned to the sump due to pressurization by ambient heat. A capacitance probe is submerged in the LNG in the sump and provides a dielectric that is compared by a microprocessor with the dielectric for pure methane at the same temperature to determine the purity of the LNG. An approximate linear relation between density and dielectric may be used to determine density and mass flow for the LNG from the measured dielectric.

Abstract: A system for dispensing cryogenic liquid to a use device includes a bulk storage tank providing LNG to a sump containing a meter submerged in LNG. A temperature probe is also submerged in the LNG. A dispensing line is positioned between the meter and dispensing hose and includes a dispensing valve. A drain line bypasses the dispensing valve and features a check valve so that LNG trapped in the hose after dispensing is returned to the sump due to pressurization by ambient heat. A capacitance probe is submerged in the LNG in the sump and provides a dielectric that is compared by a microprocessor with the dielectric for pure methane at the same temperature to determine the purity of the LNG. An approximate linear relation between density and dielectric may be used to determine density and mass flow for the LNG from the measured dielectric.

Abstract: A cryogenic fluid delivery system includes a pump having a pumping cylinder within which a sliding pumping piston is positioned. The pump also includes an actuating cylinder within which a sliding actuating piston is positioned and a supplemental linear actuator, such as a hydraulic cylinder. The pumping and actuating pistons and supplemental linear actuator are joined by connecting rods. A portion of the cryogenic liquid pumped from a storage tank is vaporized in a heat exchanger and introduced into the actuating cylinder to power the pump with the assistance of the supplemental linear actuator so that high pump discharge pressures may be obtained.

Abstract: A breakaway device joins a portion of a dispensing hose that is connected to a fueling station with a portion of a dispensing hose that is joined to a coupling that connects to a vehicle during fueling. The breakaway device includes a pair of leg members that are joined by their proximal ends to the dispensing hose portions. The distal ends of the leg members are joined at an angle to a frangible member that includes a pair of inner segments that are joined in an abutting fashion by a surrounding frangible sleeve. When a driveaway occurs, the leg members are pulled apart and exert a bending moment on the frangible member. As a result, the frangible member breaks which prevents significant damage to the station. A pneumatic line that provides pressurized air to open the station dispensing valve is attached to each leg member so that when the frangible member breaks, the pneumatic line is ruptured so that pressurized air is no longer delivered to the dispensing valve.

Abstract: A system for transferring and conditioning a cryogenic liquid includes a replenishing tank containing a supply of cryogenic liquid, a bulk tank and a pump positioned there between. The pump causes a stream of the cryogenic liquid to flow from the replenishing tank to the bulk storage tank. A heat exchanger and parallel by-pass line are positioned between the pump and bulk storage tank. A flow control valve diverts a portion of the stream to the heat exchanger so that it is warmed and rejoined with the remaining cryogenic liquid flowing through the flow control valve. The warmed stream then flows to the bulk storage tank. The flow control valve is adjusted based upon pressures within the bulk storage tank via a pressure line in communication with the head space of the bulk storage tank and a pneumatic controller or a pressure sensor in the bulk tank head space and a programmable logic controller.

Abstract: A system for dispensing cryogenic liquid to a use device includes a bulk storage tank providing LNG to a sump containing a meter submerged in LNG. A temperature probe is also submerged in the LNG. A dispensing line is positioned between the meter and dispensing hose and includes a dispensing valve. A drain line bypasses the dispensing valve and features a check valve so that LNG trapped in the hose after dispensing is returned to the sump due to pressurization by ambient heat. A capacitance probe is submerged in the LNG in the sump and provides a dielectric that is compared by a microprocessor with the dielectric for pure methane at the same temperature to determine the purity of the LNG. An approximate linear relation between density and dielectric may be used to determine density and mass flow for the LNG from the measured dielectric.

Abstract: A cryogenic system that off-loads cryogenic liquid from a delivery vehicle and pumps the cryogenic liquid to a storage tank includes an interlock that enables the pneumatic valves which control the flow of the cryogen. The interlock includes a pneumatic relay, a pneumatic line and a pressure sensing line. The pneumatic line transfers pressurized air to the pneumatic relay while the pressure sensing line pressurizes the pneumatic relay when hoses from a delivery truck are connected to the system. The pneumatic relay includes a housing that defines a chamber with a piston having an arcuate passage located therein. When a hose from the delivery truck is connected to the system, the pressure sensing line detects a change in pressure and pressurizes the pneumatic relay. The pressure displaces the piston of the pneumatic relay which aligns the arcuate passage of the relay with the pneumatic valve to allow pressurized air to travel to the pneumatic valve thereby opening the pneumatic valve.

Abstract: A liquefaction system includes a source tank containing a supply of liquid nitrogen with a head space there above filled with nitrogen vapor. A pump transfers the liquid nitrogen to a heat exchanger. The heat exchanger also receives natural gas that has been processed in a purifier. The natural gas is liquefied by free cold from the liquid nitrogen so that liquid natural gas (LNG) is produced. The LNG travels to an LNG destination tank for storage and/or transport. The liquid nitrogen is vaporized in the heat exchanger. The resulting nitrogen gas is directed to a process system that may include, for example, cylinders for welding or other applications. Between liquefaction cycles, the purifier is regenerated by a vacuum and nitrogen vapor from the head space of the source tank. Steel shot is mixed with absorbent in the purifier so that the absorbent is cooled for increased performance.

Abstract: A system for dispensing cryogenic liquid to a use device includes a bulk storage tank providing liquid natural gas (LNG) to a sump containing a meter submerged in LNG. A temperature probe is also submerged in the LNG. A dispensing line is positioned between the meter and dispensing hose and includes a dispensing valve. A drain line bypasses the dispensing valve and features a check valve so that LNG trapped in the hose after dispensing is returned to the sump due to pressurization by ambient heat. A capacitance probe is submerged in the LNG in the sump and provides a dielectric that is compared by a microprocessor with the dielectric for pure methane at the same temperature to determine the purity of the LNG. An approximate linear relation between density and dielectric may be used to determine density and mass flow for the LNG from the measured dielectric.

Abstract: A cryogenic fluid delivery system includes an insulated storage tank containing a supply of cryogenic liquid, a pump, a heat exchanger and a gas and liquid mixer. The pump includes a pumping cylinder within which a sliding pumping piston is positioned. The pump also includes an actuating cylinder within which a sliding actuating piston is positioned. The pumping and actuating pistons are joined by a connecting rod. A portion of the cryogenic liquid pumped from the storage tank by the pumping piston and cylinder is vaporized in the heat exchanger and introduced into the actuating cylinder on alternating sides of the actuating piston to power the pump. The vaporized cryogen is also used to heat the pumped cryogenic liquid in the mixer. The conditioned cryogenic liquid is then dispensed from the mixer via a dispensing line.

Abstract: A breakaway device joins a portion of a dispensing hose that is connected to a fueling station with a portion of a dispensing hose that is joined to a coupling that connects to a vehicle during fueling. The breakaway device includes a pair of leg members that are joined by their proximal ends to the dispensing hose portions. The distal ends of the leg members are joined at an angle to a frangible member that includes a pair of inner segments that are joined in an abutting fashion by a surrounding frangible sleeve. When a driveaway occurs, the leg members are pulled apart and exert a bending moment on the frangible member. As a result, the frangible member breaks which prevents significant damage to the station. A pneumatic line that provides pressurized air to open the station dispensing valve is attached to each leg member so that when the frangible member breaks, the pneumatic line is ruptured so that pressurized air is no longer delivered to the dispensing valve.

Abstract: A cryogenic fluid delivery system includes an insulated storage tank containing a supply of cryogenic liquid, a pump, a heat exchanger and a gas and liquid mixer. The pump includes a pumping cylinder within which a sliding pumping piston is positioned. The pump also includes an actuating cylinder within which a sliding actuating piston is positioned. The pumping and actuating pistons are joined by a connecting rod. A portion of the cryogenic liquid pumped from the storage tank by the pumping piston and cylinder is vaporized in the heat exchanger and introduced into the actuating cylinder on alternating sides of the actuating piston to power the pump. The vaporized cryogen is also used to heat the pumped cryogenic liquid in the mixer. The conditioned cryogenic liquid is then dispensed from the mixer via a dispensing line.

Abstract: In a system for detecting overflow of a liquid cryogen storage tank, a differential pressure gauge measures the pressure of the tank at the top and bottom of the tank while liquid cryogen is introduced into the tank. Once the measurement reaches a predetermined amount, the operator terminates the fill. Alternatively, the differential pressure gauge sends a signal to the controller and the controller shuts the valves off. The tank includes an outlet pipe connected to either an audible device or avisual device and a vent stack. The excess cryogen, liquid or vapor, flows out of the tank through the outlet pipe. The audible device whistles when vapor passes through but is silent when the liquid passes through the audible device. This audible device provides a back-up warning which signifies when liquid cryogen is flowing out of the tank so that the operator may shut off the valves.