Ambient Vaporizer

  • Ambient air vaporisers require no external source of energy; and enables vaporization through exchange of heat with the surrounding air. The liquefied gas is vaporized, and warmed to almost the surrounding temperature, and finally led to the users in its gaseous state.

    The vaporisers are for use with liquid:

    • Nitrogen
    • Oxygen
    • Argon
    • Carbon Dioxide
    • Nitrous Oxide
    • LNG

    Design Specifications

    Isisan offers a full range of ambient air vaporizers in different versions and for different applications. Our ambient air vaporisers have the following properties:

    • Designed and manufactured according to PED 97/23/EC;
    • Has CE marking
    • Max. allowable working pressure 40 bar
    • Cleaned for oxygen service
    • Seismic requirements acc. to uniform building code-zone 4
    • Low pressure drop
    • Efficient fin tube design
    • Optimized external and internal surfaces for optimum convection

    Vaporiser Options

    Ambient air vaporiser options are:

    • Fin tube vaporisers
    • Fan assisted vaporisers

    Fin tube vaporisers rely on natural convection while fan assisted models are equipped with an electric motor operated fan to enhance air flow and increase efficiency.

    How Do Ambient Air Vaporisers Work?

    Since the surrounding air is at a higher temperature than the product; heat from surrounding air is transferred to the product in the vaporiser.

    While ambient air vaporisers are in use, it is normal to see a mist forming. This is caused by the moisture in the air, condensing and freezing. The intense cold of cryogenic liquid and the moisture in the surrounding air will create frost and ice will build up on vaporiser tubes, gradually.

    For this reason ambient air vaporisers have a limited running time before the frost and ice has to be cleared from the tubes.

    The performance of ambient air vaporisers may be impaired during prolonged periods of severe cold weather. This will create additional frost and ice formation, causing a performance drop.

    Method of Heat Transfer

    Fin Tube Vaporisers

    Heat from the air is transferred through natural convection to the vaporiser pipe. The natural convection is created by the temperature difference between the atmospheric air and the air around the cold pipe.

    Heat is conducted from the outside of the pipe to the inner wall. Heat is transferred through forced convection from the inner wall to the product. The forced convection is created by the fluid flow in the pipe.

    Fan Assisted Vaporisers

    Fan assisted vaporisers are ambient vaporisers that use a fan to increase the efficiency of the vaporiser. Unlike standard ambient vaporisers, the finned tubes are installed within a framework and are enclosed by walls on all sides. The top normally consists of fan housing with side openings to draw in air. The bottom is kept open. An electric fan in the top of the frame provides forced draught downward over the tubes. Forced convection is more efficient than natural convection; therefore fan assisted vaporisers have better efficiency.