Abstract: Embodiments of the invention provide methods, systems, and apparatus for delivering gas in a liquefied state at a controlled rate. The liquefied gas may be transported in ton cylinders by placing the ton cylinder on a transportation pallet. The transportation pallet containing the ton cylinder may be placed on a heating saddle so that a surface of the cylinder is in contact with a surface of the heating saddle. Heating fluid may flow through the heating saddle, thereby heating the liquid in the cylinder through the cylinder walls. Furthermore, the vapor pressure of the gas in the cylinder may be monitored and maintained at a desired level by regulating the flow of heating fluid through the saddle. Therefore, embodiments of the invention allow the maintenance of gas flow rates in a cylinder without removing the cylinder from its transportation pallet.

Abstract: A system for ammonia vapor generation includes a liquid ammonia supply source, a vapor generation tank including an inlet to receive liquid ammonia from the supply source and an outlet to discharge ammonia gas from the vapor generation tank, a first heat transfer system to cool liquid ammonia fed from the supply source to the vapor generation tank and to provide external cooling to the vapor generation tank, and a second heat transfer system to heat liquid ammonia within the vapor generation tank. The first and second heat transfer systems facilitate the discharge of ammonia gas from the vapor generation tank at a substantially constant flow rate and pressure.

Abstract: Provided is a system for controlled vaporization of a liquid chemical. The system includes: (a) an evaporation vessel connected to receive a liquid chemical which is carrier gas free; (b) a mechanism for maintaining the liquid chemical in the evaporation vessel at a substantially constant level; and (c) a mechanism for controlling the temperature of the liquid chemical in the evaporation vessel to a desired value, the controlling mechanism including: (I) a system for cooling the liquid chemical, and (II) a heater inside the evaporation vessel for heating the liquid chemical. Also provided, are methods of controlled delivery of a vaporized liquid chemical. The above systems and methods are particularly applicable to the semiconductor manufacturing industry.

Abstract: Provided are a system and method for saturating a gas with a vapor from a liquid chemical. The system includes: (a) a saturation vessel connected to receive a liquid chemical and a carrier gas; (b) a gas sparger in the saturation vessel for sparging the carrier gas into the liquid chemical; (c) means for maintaining the liquid chemical in the saturation vessel at a substantially constant level; (d) means for controlling the temperature of the liquid chemical in the saturation vessel to a desired value, comprising (I) a system for cooling the liquid chemical, and (ii) a heater inside the saturation vessel extending vertically in the liquid a distance at least half of the height of the liquid chemical level for heating the liquid chemical; and (e) means for controlling the pressure of the saturated gas to a desired value. The invention also relates to novel methods and systems for controlled delivery of a vaporized liquid chemical.