Process and apparatus for electrogalvanic coating of metal items

Abstract

In a method of electroplating a metal article through a sequence of chemical and electrochemical treatment stages, each of said treatment stages comprising the steps of: a) placing the drum containing the article in a centrifuge; b) delivering the first chemical treatment liquid to a centrifuge; c) processing; d) draining the first chemical treatment liquid from the centrifuge; e) performing centrifugation of the item to recover the liquid; f) feeding the centrifuge Convey wash water; g) perform washing; h) discharge wash water from centrifuge; i) perform centrifugation of items to recover said water; j) transfer drum to another section, or repeat with additional chemical treatment fluid above steps. Washing after the chemical treatment stage in the same section where the treatment has already been done can greatly reduce the number of stations. In addition, centrifugation after each treatment or washing enables the recovery of liquid, which reduces the consumption of liquid and prevents The problem of entrainment of liquid from one section to another, thus also preventing environmental pollution. The plant for carrying out the method comprises a sequence of linearly arranged sections (A) with an automatic loading section at the entrance and an automatic unloading section at the exit, wherein the items to be processed are loaded into the top In an open perforated cylindrical drum (D), the drum (D) is automatically moved from one section to another by carriages (C) running on rails (B) that run along the The entire length of the section extends over the section. The use of an open drum (D) instead of the traditional door-closed barrel enables the loading and unloading of items to be completed in a fully automatic manner at the end of the plant, which greatly saves labor and is of great importance to the operation. There is no risk to the health of personnel.

Description

technical field [0001] The present invention relates to a method and apparatus for the electrolytic deposition of a protective coating on metal objects, typically the galvanization of screws and the like. A description of such applications will be given hereafter, however, it is obvious that what is said also applies to other types of protective and / or decorative coverings in other metals for objects of any kind. Background technique [0002] It is known that conventional galvanizing plants consist essentially of a sequence of operating sections in which the screws loaded into perforated barrels are subjected to the various treatments required to obtain a protective covering by methods well known to those skilled in the art Floor. By way of example, a device with a zinc coating thickness of 12 μm and a production capacity of 1800 kg / h of screws will be presented. Such a plant is provided with a sequence of stages / sections as follows: [0003] -N.2 chemical cleaning sectio...

AI Technical Summary

Problems solved by technology

[0022] 3. Frequent analysis and testing of chemical solutions is required;

[0023] 4. A large amount of highly polluted liquids exposed will continue to emit harmful steam and toxic gases, and the liquids also need to be purified;

[0024] 5. Huge space occupation;

[0025] 6. The processing device system requires very frequent mechanical maintenance;

[0026] 7. Labor required for loading / unloading and monitoring at each stage;

[0027] 8. The damage to the device and its connected auxiliary facilities and adjacent structures is very rapid

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