Patent DE-102009013164-A1 (DE)
Title: Method for partial galvanization of elongated products in electrolytes of electrolytic cell, which is associated to a bath current source, comprises placing the product for the treatment in the electrolytic cell between anode and cathode
Inventor: HUEBEL EGON
IPC: C25D21/10
Filed: 2009-03-07
Abstract: The method for partial galvanization of elongated products (1) in electrolytes (12) of electrolytic cell (4), which is associated to a bath current source, comprises placing the product for the treatment in the electrolytic cell that consists of a cathode (6) and an anode (5), between the anode and the cathode in electrical contact-less manner and rotating in bath current source with a revolution around its longitudinal axis. The anode, the cathode and/or the product arranged plane parallel to each other are moved for electrolyte exchange and/or for gas dissolution from the surface. The method for partial galvanization of elongated products (1) in electrolytes (12) of electrolytic cell (4), which is associated to a bath current source, comprises placing the product for the treatment in the electrolytic cell that consists of a cathode (6) and an anode (5), between the anode and the cathode in electrical contact-less manner and rotating in bath current source with a revolution around its longitudinal axis. The anode, the cathode and/or the product arranged plane parallel to each other are moved for electrolyte exchange and/or for gas dissolution from the surface in cyclic- or vibration-like manner. The galvanization of the product is carried out in electrolyte in which metal electrochemically deposited on the product is constant. The surface area of the product is cathodically and anodically or reversibly treated in a revolution. A metallization of the cathode of the electrolytic cell is prevented through placing the product near to the cathode during galvanization. The metallization of the cathode is prevented through electric conductive metal layer on the surface of the cathode that is not metallizable. Low cathodic current density emerges through an active surface of the cathode that is larger than the momentary active anodic surface of the product. A metal deposition on the cathode is prevented through cooling the cathode at a surface temperature below the process temperature of the electrolyte. The metallization of the surface of the cathode is prevented through the use of electrolytes in the area of the cathode that consists of metalion that is separated from the cathode. For preventing the metal deposition on the cathode through an ion selective and fluid tight membrane, the electrolyte in the area of the cathode as catolyte that consists of metalions is separated from process electrolyte that consists of metalions and exists in the product and the anode. The requirement of energy for cooling the cathode through an ion-permeable and heat-insulation layer as heat insulator is prevented against the electrolyte present at process temperature. The electrolytic cell is operated with the bath current source as direct current source, unipolar pulse current source, bipolar pulse current source or with technical alternating current. The electrolytic cell is electrochemically treated and/or galvanized through shielding the areas of the product against the anode. The partial electrochemical surface of the product to be treated is pre-selected and admitted by adjustable shielding. The product is partially galvanized by limited protection lacquer or safety caps. The product is promoted on supports by the electrolytic cell in a plane that lies plane-parallel to the plane and parallel electrodes. The product is pressed by a rotating band or a pendulum device in the area of the cathode against the support and is transported by spacer through the electrolytic cell. The guiding of the gas emerging during the treatment is accelerated through an oblique position transverse to transport direction of the plane of the electrode and the plane of the product. Gas emerging through a vibration-like or cyclic movement of the electrodes and/or the product in any direction is supported by the surface. During loading and unloading the product in and from the electrolytic cell, an electrode is sectionally engaged and/or disengaged corresponding to filling the electrolytic cell, where the flow of the bath current source is adapted to energy storage at the surface of the goods to be treated. The orifice plates shield the area of the electrodes. The required size of the bath current is diminished in given throughput through a series control of two electrolytic cells. The metallization limit is influenced through blending or partial blending. The single drives promote each product through the electrolytic cell. The product positioned in a dip bath between the electrodes is rotatably moved around the longitudinal axis. The radially changed product is promoted in axial direction through the electrolytic cell. The product to be metalized is dissolved in the used electrolyte. During galvanization, the metallization of the cathode is prevented through placing the product near the cathode. An independent claim is included for a device for partial galvanization of elongated products in electrolytes of electrolytic cell.