Abstract: A system for removing a thin metal film is disclosed. The system comprises an inclined metal plate electrode for guiding a downward electrolyte flow, an auxiliary electrode placed on either the upstream or downstream side of the metal plate electrode such that a part of the auxiliary electrode is immersed into the electrolyte, and a power supply for applying a DC voltage to the both electrodes. The system is used to remove a metal thin film on the surface of an insulator by making the electrolyte flowing down the metal plate electrode strike against the metal thin film while the DC voltage is applied to the metal plate electrode and auxiliary electrode.

Abstract: A system for removing a thin metal film is disclosed. The system comprises an inclined metal plate electrode for guiding a downward electrolyte flow, an auxiliary electrode placed on either the upstream or downstream side of the metal plate electrode such that a part of the auxiliary electrode is immersed into the electrolyte, and a power supply for applying a DC voltage to the both electrodes. The system is used to remove a metal thin film on the surface of an insulator by making the electrolyte flowing down the metal plate electrode strike against the metal thin film while the DC voltage is applied to the metal plate electrode and auxiliary electrode.

Abstract: A first and second electrostatic sorting sections are arranged below a tribo-electrifying device in this order in a vertical direction to form a sorting electrostatic field between a drum electrode and an opposing electrode. Plastic pieces separated from the other plastic pieces by the sorting electrostatic field in the first electrostatic separating section are introduced into a sorting electrostatic field in the second electrostatic separating section for second separation, thereby increasing the separation purity and recovery rate of plastic pieces.

Abstract: A feed tray (22) for guiding tribo electrified plastic pieces (2) to a drum electrode (6) is provided with a vibrator (23), thereby making it possible to vibrate the plastic pieces (2) to form a thin uniform layer, and to reliably apply appropriate image force and centrifugal force to the plastic pieces (2) fed to the drum electrode (6); thus, the plastic pieces (2) can be separated according to kind with high precision.

Abstract: A device for electrostatically separating different kinds of crushed plastic pieces and correctly sorting them according to kind. The device has a classifying section (40) for classifying plastic pieces according to size, a frictional charging device (17), a pair of drum type electrostatic separating devices (41), and collecting sections (26) disposed below the electrostatic separating devices. Partition walls (52-55) for partitioning the collecting sections are constructed to be horizontally movable according to the fall positions associated with the polarity and amount of electric charge of each plastic piece (16). Therefore, separation can be correctly effected without changing the voltage from a high voltage power source device (24).

Abstract: The invention provides a plastic sorting method and apparatus, which, when plastic pieces comprising a plurality of types of resin plastics are agitated and frictionally charged, are able to impart the plastic pieces a necessary amount of charge or polarity for the thorough separation even if the difference in the amount of the different types of plastic pieces is large and to increase the recovery rate. If the amount of a specified type plastic pieces (1) to be recovered is small, the agitation and the electrostatic separation is carried out after adding the specified type plastic pieces (1) as auxiliary frictional charging material (21) into the frictional charging device (3), and the auxiliary frictional charging material (21) remains in the frictional charging device (3) and is used repeatedly.

Abstract: When plastic pieces of plural different types of resins fed into a hopper are agitated to be triboelectrically charged, the plastic pieces are not imparted with sufficient amounts of charges or proper polarities which are required for separation of the plastic pieces if there are great differences in quantity between the different types of plastic pieces. This makes it impossible to properly separate the plastic pieces. Where the amount of pieces of a particular plastic to be separated is small, pieces of the particular plastic are additionally fed as a triboelectrification agent into a triboelectric charger (3) and agitated with the plastic pieces. Thus, different types of plastic pieces (1) (e.g., PVC and PE) are prevented from being imparted with the same polarity and are imparted with different amounts of charges, so that the separation can assuredly be carried out in an electrostatic separating section (G) for recovery of the particular plastic pieces.

Abstract: An electric screen device for preventing creatures from intruding into a water channel, which comprises a pair of opposed electrode assemblies disposed on opposite sides of a water intake channel, and a dc pulse applying device 13 for applying dc pulses between the electrode assemblies. In such electric screen device, the product of the peak value of the intensity of an electric field produced between the electrode assemblies by the dc pulse applying device and the body length of creatures to be prevented from intrusion into the water channel is not less than 0.1 V, the dc pulse applying time is within the range of 2-200 msec, and the duty factor of the dc pulse is not more than 0.5.

Abstract: A frictional charging device (30) for charging crushed chips (1) of a plurality of kinds of plastics by stirring them. A stirring vessel (31) has a friction assisting material (52) put therein, the particles of the friction assisting material (52) being so formed that they are larger than the plastic chips (1). A delivery port (34) formed in one end of the stirring vessel (31) is provided with a plurality of delivery area wires (47) arranged at predetermined intervals and parallel to each other. The spacing between adjacent delivery area wires (47) is set larger than the plastic chips (1) and smaller than the particles of the friction assisting material (52).

Abstract: The present invention provides an apparatus to prevent the entrance of aquatic species into the intake watercourse having a U-shaped cross section with a narrow bottom and a wide surface, in which oppositely facing electrodes are installed vertically along the side walls on both sides of the intake watercourse, and the distance between the upper ends of the electrodes is made greater than the distance between the lower ends of the electrodes, and a voltage is impressed between the both electrodes. Since the electric barrier intensity is smallest at the surface of water and becomes greater as it goes toward the bottom of water, the river fish moving around the bottom of water make a U-turn when they reach the strong electric barrier, or alternatively, after reaching the strong electric barrier, they move upward to where the electric barrier is weaker and then make a U-turn, thereby the entrance of aquatic species into the intake watercourse can be prevented.