Abstract: Herein disclosed is an air cleaner comprising: means defining an air passage, a plurality of corona discharge electrodes and a coupling discharge electrode arranged upstream of an air passage, being connected to a high voltage source for effecting a corona discharge downstream of the air passage for collecting the air-borne dust which has been charged by the corona discharge. The coupling discharge electrode is formed as a plate with a number of circular apertures therein, and each of the discharge electrodes has a multiplicity of leading ends shaped as sharp points arranged at the respective centers of the circular apertures and terminating generally on the plane thereof. The velocity of the air flow is increased in passage through the apertures to prevent the air cleaner from getting clogged.

Abstract: A cold storage body that comprises a hermetically sealed vessel made of aluminum alloy in which a cold storage medium in an appropriate amount is enclosed with a space remaining within the vessel filled with a compressed inert gas at an appropriate pressure. The vessel may comprise a can type trunk portion of a thin aluminum sheet having an open end with a cover member closing the open end of the trunk member. The thus formed cold storage body has sufficient strength regardless of temperature variation for cooling the cold storage body as well as a long durability and a high corrosion resisting property.