Abstract: A horn is described for transmitting sound from a transducer to a heated chamber containing an object which is levitated by acoustic energy while it is heated to a molten state, which minimizes heat transfer to thereby minimize heating of the transducer, minimize temperature variation in the chamber, and minimize loss of heat from the chamber. The forward portion of the horn, which is the portion closest to the chamber, has holes that reduce its cross-sectional area to minimize the conduction of heat along the length of the horn, with the entire front portion of the horn being rigid and having an even front face to efficiently transfer high frequency acoustic energy to fluid in the chamber. In one arrangement, the horn has numerous rows of holes extending perpendicular to the length of horn, with alternate rows extending perpendicular to one another to form a sinuous path for the conduction of heat along the length of the horn.

Abstract: Apparatus for sterilizing containers, for example open-topped plastic pots for receiving foodstuffs, comprises an aerosol generator which atomizes a liquid sterilizing agent and subsequently entrains the droplets of sterilizing agent in a carrier gas stream for delivery to a corona discharge wherein a charge is imparted to the droplets. The apparatus also comprises means for establishing an electrostatic field about a container to be sterilized whereby the charged droplets will be directed to the surface of the container to form a uniform coating thereon. The efficiency of the apparatus is enhanced by switching the polarity of the electrostatic field, for example as a function of corona current and also by minimizing the possibility of liquid sterilizing agent collecting on surfaces of the apparatus and subsequently falling on a surface of a container being treated.

Abstract: Open-topped containers are sterilized by employing an electrostatic field to insure complete coating of the interior surface of such containers with a sterilizing agent. The sterilizing agent is supplied in liquid form, ultrasonically atomized, the thus formed droplets entrained in a stream of carrier gas and an electrical charge imparted to the entrained droplets so that they will be influenced by the electrostatic field created in the containers.