Abstract:
A mobile system for dispensing cryogenic liquid to a use point includes a low pressure bulk tank containing a supply of cryogenic liquid and a high pressure sump in communication with the bulk tank so as to receive cryogenic liquid therefrom. A heat exchanger is in communication with the sump and selectively receives and vaporizes a portion of cryogenic liquid from the sump. The resulting vapor is directed to the sump so as to increase the pressure therein. A pressure builder is in circuit between the sump and the bulk tank. The pressurized cryogenic liquid may be dispensed from the sump via a dispensing hose or directed to the pressure builder so as to pressurize the bulk tank. If the latter is selected, pressurized cryogenic liquid is dispensed from the bulk tank via a second dispensing hose. Operation of the system valves is automated by a controller.
Abstract:
A high pressure cryogenic fluid dispensing system features a tank containing a cryogenic liquid with a liquid side and a head space there above. A pressure building coil featuring a section of parallel heat exchangers and a section of series heat exchangers receives liquid from the tank through a pressure building regulator valve and a pair of surge check valves. The liquid flashes to gas in the section of parallel heat exchangers and the resulting gas is forced to the section of series heat exchangers where it is pressurized and warmed. The gas may be directed to a warming coil for dispensing and to the head space of the tank to rapidly pressurize it. Gas traveling to the head space flows through an vapor space withdrawal control valve. The vapor space withdrawal control valve and pressure building regulator valve may be automated via a controller that provides pressure building when the tank pressure drops below the system operating pressure.
Abstract:
A system that generates high pressure cryogenic gas includes a storage tank that contains a liquid cryogen and a feed line that supplies the liquid cryogen to a pressure pod. The pressure in the pressure pod gradually increases due to ambient heat to a first predetermined level. A regulator valve opens at the first predetermined level thereby directing the liquid cryogen to a heat exchanger where it is vaporized and directed back to the pressure pod to raise the pressure therein further. Once the pressure in the pressure pod reaches a second predetermined level, a dispense valve opens. The pressurized liquid cryogen is directed through the dispense valve to a vaporizer that vaporizes the high pressure liquid cryogen to a cryogenic gas that may be dispensed and stored in a tank.
Abstract:
A dispensing system allows cryogenic liquid to be dispensed from either a primary bank manifold and associated cylinders or a secondary bank manifold and associated cylinders. Each manifold includes a gas header and a liquid header. The associated cylinders communicate with the gas header through flexible lines and excess flow check valves and the liquid header through flexible lines and spring-loaded check valves. An automatic control system selects between dispensing from the primary bank manifold or the secondary bank manifold. A pressure gauge detects the pressure of the cryogenic liquid from the dispensing manifold. The pressure gauge is in communication with a controller which opens and closes the appropriate valves to begin dispensing cryogenic liquid from the originally idle manifold if the detected pressure drops below a predetermined minimum. After the manifold is switched over, the controller checks the pressure in the non-selected manifold. If pressure buildup occurs in the non-selected manifold due to residual liquid in the associated cylinders, the system is reconfigured to dispense the residual liquid.
Abstract:
A portable self-contained delivery station for liquid natural gas (LNG) is provided on a movable skid frame and equipped with an instant -on delivery system which may initiate LNG delivery immediately to a use vehicle. The skid is equipped with a spill containment feature such that the LNG may be contained in the event of spillage. A variable speed pump both controls LNG dispensing and saturation levels of the stored LNG. The pump is submerged in a sump tank which is separate from the bulk storage tank. The sump tank is flooded with an amount of LNG such that the pump is submerged. Delivery of LNG may thus occur instantly, without pre-cooling of the pump or associated meter.
Abstract:
A mobile system for dispensing cryogenic liquid to a use point includes a low pressure bulk tank containing a supply of cryogenic liquid and a high pressure sump in communication with the bulk tank so as to receive cryogenic liquid therefrom. A check valve is in circuit between the bulk tank and the sump. A heat exchanger is in communication with the sump and selectively receives and vaporizes a portion of cryogenic liquid from the sump when the sump is full as detected by a liquid level sensor. The resulting vapor is directed to the sump so as to increase the pressure therein. The check valve closes when the pressure building within the sump is initiated. The pressurized cryogenic liquid is dispensed from the sump via a dispensing hose. Operation of the system valves is automated by a controller.
Abstract:
A cryogenic vessel features an inner tank containing cryogenic liquid with a head space above and a jacket surrounding the inner tank. An internal pressure builder coil is helically disposed about the inner tank, connected to the jacket and in communication with the bottom of the inner tank. An external pressure building heat exchanger is connected to the internal pressure builder coil and the head space of the inner tank. Liquid from the inner tank flows into the internal pressure builder coil and the exiting fluid is driven by a resulting pumping action to the external pressure building heat exchanger where it is vaporized and warmed. The warmed gas is directed to the head space of the inner tank to rapidly build the pressure therein. Gas may be dispensed directly from the head space of the vessel via an economizer valve. Alternatively, liquid may be withdrawn from the inner tank by a dip tube and vaporized in a vaporizer and dispensed.
Abstract:
A system and method for dispensing subcooled CO2 liquid includes a vacuum insulated bulk tank containing a supply of the liquid CO2. A pressure builder having an inlet in communication with a bottom portion of the bulk tank and an outlet in communication with a top portion of the bulk tank vaporizes liquid from the bulk tank and delivers the resulting gas to the top portion of the tank so as to pressurize it. A baffle is positioned within the bulk tank. Below the baffle, a refrigeration system is connected to the heat exchanger coil so that a refrigerant fluid is supplied to and received from the heat exchanger coil so that the liquid below the baffle is subcooled and the liquid above the baffle is stratified. A liquid fill line is in communication with the interior of the bulk tank via a fill line opening that is positioned above the baffle. A liquid feed line is in communication with a bottom portion of the interior of the bulk tank so that subcooled liquid may be dispensed.
Abstract:
A system and method for dispensing subcooled CO2 liquid includes a vacuum insulated bulk tank containing a supply of the liquid CO2. A pressure builder having an inlet in communication with a bottom portion of the bulk tank and an outlet in communication with a top portion of the bulk tank vaporizes liquid from the bulk tank and delivers the resulting gas to the top portion of the tank so as to pressurize it. A baffle is positioned within the bulk tank. Below the baffle, a refrigeration system is connected to the heat exchanger coil so that a refrigerant fluid is supplied to and received from the heat exchanger coil so that the liquid below the baffle is subcooled and the liquid above the baffle is stratified. A liquid fill line is in communication with the interior of the bulk tank via a fill line opening that is positioned above the baffle. A liquid feed line is in communication with a bottom portion of the interior of the bulk tank so that subcooled liquid may be dispensed.
Abstract:
A system for dispensing cryogenic liquid to a use point includes a bulk tank containing a supply of cryogenic liquid and a pressure builder that is in communication with the tank via a pressure building valve. The pressure builder uses heat exchangers to vaporize a portion of the cryogenic liquid as needed to pressurize the bulk tank. The pressurized cryogenic liquid is dispensed through a dispensing line running from the bottom of the tank. A vent valve also vents vapor from the tank to control pressure. Operation of the vent and pressure building valves is automated by a controller that receives data from sensors. The controller determines the required saturation pressure for the tank and varies the tank pressure to match and provide a generally constant outlet pressure depending on conditions of the cryogenic liquid.