Ullage

About: Ullage is a research topic. Over the lifetime, 501 publications have been published within this topic receiving 4704 citations. The topic is also known as: headspace.

Vapor recovery system for fuel storage tank

Abstract: A vapor recovery system for a fuel storage tank. The system includes a pair of VOC adsorbent canisters that alternately recover VOC vapors from the fuel tank ullage or are regenerated. Regeneration of the VOC adsorbent canisters is provided by exhausting the VOC vapors from the VOC canisters using a vacuum pump and back into the fuel tank ullage. When the operating pressure of the fuel tank ullage is elevated, an auxiliary VOC adsorbent canister is operated in parallel with the pair of canisters in order to recover the increased amount of VOC vapors in the tank ullage.

Auxiliary vapor recovery device for fuel dispensing system

Abstract: An auxiliary vapor recovery device is described for use with a fuel dispenser for delivery of fuel from tanks into a vehicle and a recovery apparatus for return of hydrocarbon vapor/air mixture displaced by fuel delivery to ullage spaces of the storage tanks interconnect by a piping manifold. The auxiliary vapor recovery device includes a vacuum pump and a canister containing a substance for removal of molecules of hydrocarbon from a vapor/air mixture. The device also has a system of conduits, including between the vacuum pump and ullage space piping system for flow to and from the ullage space, to the canister, between the vacuum pump and canister, and from the canister for release of air. The device also includes a solenoid valve system with first and second solenoid valves positioned in the conduit system, the solenoid valve system having a first (recovery) condition for permitting flow of hydrocarbon vapor/air mixture from the ullage space, through the canister for removal of hydrocarbon vapor and release of air, a second (off) condition for restricting flow of vapor in the conduit system and a third (stripping) condition for establishing an increased vacuum condition within the canister for return of hydrocarbon vapor to the ullage space. A solenoid valve system control apparatus causes the solenoid valve system to move among the first, second and third conditions.

Cyclic membrane separation process

Abstract: A cyclic process for controlling environmental emissions of volatile organic compounds (VOC) from vapor recovery in storage and dispensing operations of liquids maintains a vacuum in the storage tank ullage. In the first part of a two-part cyclic process ullage vapor is discharged through a vapor recovery system in which VOC are stripped from vented gas with a selectively gas permeable membrane. In the second part, the membrane is inoperative while gas pressure rises in the ullage. In one aspect of this invention, a vacuum is drawn in the membrane separation unit thus reducing overall VOC emissions.

Storage tank for a cryogenic fluid with a partitioned cryogen space

Abstract: A cryogenic storage tank comprises a partition that divides a cryogen space into a main storage space and an auxiliary space. A valve disposed inside the cryogen space is associated with a first fluid passage through the partition. The valve comprises a valve member that is actuatable by fluid forces within the cryogen space. A second fluid passage through the partition comprises a restricted flow area that is dimensioned to have a cross-sectional flow area that is smaller than that of a fill conduit such that there is a detectable increase in back-pressure when the main storage space is filled with liquefied gas. A preferred method comprises establishing a vapor-filled ullage space when the main storage space is being vented and re-filled with cryogenic fluid, by draining liquefied gas from the auxiliary space through the first fluid passage under the influence of a vapor pressure differential permitted by the partition. If the vapor pressure differential reverses during re-filling, the valve can close to preserve the vapor-filled ullage volume. Re-filling is stopped when an increase in back pressure is detected during re-filling.

Liquid propellant densification

Abstract: Super cooling the cryogenic liquid propellant in a vehicle propellant tank densities the propellant allowing the vehicle propellant tank to carry more fuel in the same volume tank while lowering the vapor pressure and thus the tank operating pressure Lowering the tank operating pressure reduces the stress and therefore allows the walls of the tank to be thinner Both the smaller tank volume and thinner tank wall results in an overall smaller and lighter vehicle with increased payload capability The cryogenic propellant can be supercooled well below the normal boiling point temperature level by transporting the liquid propellant from the vehicle tanks to a ground based cooling unit which utilizes a combination of heat exchanger and compressor The compressor lowers the coolant fluid bath pressure resulting in a low temperature boiling liquid which is subsequently used to cool the recirculating liquid The cooled propellant is then returned to the vehicle propellant tank In addition to reducing the vehicle size and weight the invention also allows location of the vent valve on the ground, elimination of on-board recirculation pumps or bleed systems, smaller and lighter engine pumps and valves, lighter and more stable ullage gas, and significant reduction in tank fill operation All of these mentioned attributes provide lower vehicle weight and cost