SU1093025A1 - Unit for electrochemical stripping of wire - Google Patents

Abstract

1. UNIT FOR ELECTROCHEMISTRY. CLEANING WIRE, containing rewinding mechanisms, bipolar electrolytic-cavitation processing units with cathodic and anode sections, washing and drying devices, which, in order to improve the quality of welding wire cleaning, is provided with a scent bath installed in front of the drying device, and the anode sections are made in the form of electrolytic plasmatrons installed in front of each cathodic electrolyte-cavitation section 2. The unit according to claim 1, which is for an ohm (Oh laziness ene in a chamber Okun .ni with side windows and a solution recirculation system of nasosai

Description

The invention relates to hardware industry, in particular to equipment for treating welding and surfacing materials, and can be used to clean and prepare the surface of a wire used as an electrode and an additive material in welding structures of a responsible purpose, for example, in atomic and energetic machine; structure. N

A known apparatus for electrochemical cleaning of a wire, comprising mechanisms for unwinding and winding a wire, a bipolar cleaning unit with an electrolyte circulation system from

, a pump, a shower device for flushing the wire with water and a direct current source. The cleaning unit is implemented in the form of successively installed two split chambers, - cathodic and anodic, respectively, polarization of the wire. The cleaning process is carried out at a wire speed of 0.515 m / min.

The advantages of the installation are its compactness and low weight of the process units, the creation of certain conditions for the continuous renewal of the electrolyte in the working area, ensuring the stabilization of the current supply to

product, reliable enough and simple transport line.

However, this installation has a number of significant drawbacks, causing a low quality, quality of cleaning the wire surface and a high level of operating costs.

The presence on the surface of the cleaned wire of the oxide film - ferrous oxide, which constitutes the scale in the form of wustite, determines the low quality of the welds when using the wire as a filler and electrode material. Negative

The effect of the oxide film on the strength and plastic properties of the seam, especially on its impact strength, is that

in vustite, oxygen, when dissolved in the weld metal, forms carbon, sulfur and atomic., hydrogen, gaseous products of the reaction, which cause pores in the metal of the seam and intensify sprinkling of liquid metal from the arc zone. Splashes on the surface of the edge of the welded parts increase the possibility of the occurrence of heat penetration and slag inclusions in the weld metal ,. requires the introduction of undesirable additional operations into the welding process - cleaning the surface of parts after welding and removing splashes from the surface of the burner nozzle of the welding machine,

The low speed of the wire in the technological part of the installation, along with limited productivity, leads to a relatively long duration of the pickling process, which causes local peretrav of the wire, additional losses of the base metal, and its filling with hydrogen, which leads to the appearance of pickling fragility.

In connection with the absence in the technological part of the installation of means for drying the wire after it was rinsed with water: the possibility of penetration of hydrogen into the weld pool from the moisture on the surface of the electrode wire is aggravated.

The presence of aggressive acidic components in the electrolyte composition makes it necessary to manufacture installation units in an expensive corrosion-resistant design, makes it possible to use additional devices of the 1-pin valve and the unit to neutralize wastewater, and creates unfavorable conditions for environmental protection and sanitation. - hygienic labor standards of the exploitation service.

These shortcomings drastically reduce the level of economic parameters of the installation and, most importantly, limit its use for cleaning electrode precision wires intended for the manufacture of especially important structures, for example, surfacing of corrosion-resistant layers on atomic reactors.

The closest to the invention in its technical essence and the effect achieved is an electrochemical wire cleaning unit containing rewinding mechanisms, bipolar electrolyte-cavitation processing units with cathodic and anodic sections, stripping and drying devices.

The design feature of this unit is the completion of the cleaning unit in the form of a three-section electrolyzer of bipolar processing with an electrolyte circulation system, while the total length of the working area of the cathode sections is 1.2-1.5 times the length of the working area of the anode sections. A 57% aqueous solution of sodium carbonate is used as the electrolyte.

The main disadvantage of the unit is the presence of a residual amount of oxides on the surface of the cleaned product, causing the formation of porosity of welds and deterioration of their mechanical and technological properties.

The purpose of the invention is to improve the quality of cleaning the welding wire.

This goal is achieved by the fact that the electrochemical wire cleaning unit containing rewinding mechanisms, bipolar electrolyte-cavitation processing units with cathodic and anode sections, washing and drying devices, is equipped with a saphiling tank installed in front of the drying device, and the anode sections are made in vvde electrolyte plasma torches installed in front of each cathode electrolyte-cavitation section. In addition, the saponification bath is made in the form of a dipping chamber with side windows and a system for recirculating the solution from the pump. . On fng. 1 shows a diagram of an aggregate for ales; trochemical wire cleaning (along the movement of the wire) / FIG. 2 — cleaning unit (one bipolar block), longitudinal section; in fig. 3 is a cross section A-A in FIG. 2; in fig. 4 shows the mutual arrangement of the elements of the shutter, section BB in FIG. 3; in fig. 5 - circulating tank 4 Unit Contains rewinding mechanism 1, butt welding machine 2, ensuring the continuity of the technological process two-plane roller-correcting device 3 for straightening the wire, circulating tank 4 with compartments 5-7 individually designed for each of the working solutions, 5-7 sections, bipolar cleaning unit, cleaning unit 4, node for cleaning; with a constant current source 9, a pump 10 for supplying electrolyte to the cleaning unit 8, a collector 11 for distributing electrolyte with pipelines and control valves 12, a chamber 13 for pre-rinsing with pump 14 according to water supply, water-air washing chamber 15, oily bath 16 with lubricant supply pump 17, drying device 18 with electric heating source 19, winding device 20 with a mechanism for placing coils on cassettes (the latter are not shown conventionally). The bipolar purification unit 8 consists of two bipolar processing units, each of which contains electrolytic cavitation section 21. cleaning and section 22 electrolyte-plasma cleanup, located with a gap of one relative to another. The bipbg sections of the block are respectively filled with working electrodes 23 and 24 and have side windows 25 and 26 for passing electrolyte and on the inlet and outlet side of the wire contain a cylindrical shutter 27 and a vertical slit 28 with arc guides .9. The fasteners of section 2J and 22 are provided with brackets 30 that rest on insulators 31. Section 21 and 22 of the bipolar blocks, the chamber 13 and 15 of the tank and the saphilization bath 16 are mounted in the upper part of the circulation tank 4. The compartments of the tank 4 contain the corresponding intake pipes 32, 33 and 34 for connecting the circulators; 10, 14 and 17, and are provided with through holes 35 for passing the wire through the process units of the unit. Devices for pressing solutions from the surface of the wire, located at its exit from the compartment, are conventionally not shown. In order to preserve and stabilize the temperature characteristics of the working solutions, the electrolyte compartment 5.. is made with a ribbed frame 36, and the outer surface of the water compartment 6 is equipped with a heat insulating layer 37, made of glass wool for example. Dp of collecting accidental leaks of solutions, a pallet 38 is mounted around the perimeter of the circulation tank 4. To avoid using ancillary equipment for cooling the electrolyte and special energy sources in the unit to heat water and the lubricating medium, the electrolyte and water compartments of the circulation tank are filled adjacent to each other , and the saponification section is mounted inside the water compartment, in its upper part. Such a design of the circulating tank allows cooling of the electrolyte column (E) due to its heat being extracted with water (N.), which simultaneously leads to heating, as well as due to heat transfer of water to heat the lubricating medium (H). The unit works as follows. The corresponding compartments of the circulation tank 4 are filled with electrolyte, water and myo grease. The intended cleaning unit is installed on the rewinding mechanism, and in the CTiJncocBare apparatus 2, the front end of the wire is connected to the rear end of the previous coil into a continuous thread. The circulating pumps 10, 14, 17 are turned on and the working solutions are supplied. Through regulating valves (valves) 2 set the required intensity of pumping electrolyte through sections 21 and 22. Electrodes 23 and 24 are connected respectively to the positive and negative poles of the current source 9; include a drying device 18 and a winder drive 20. Cleaned. The 710 wire is squeezed to a necessary weight riot. On the drum of the coiler, from where it is transported to the warehouse of the finished product. The cleaning of the wire in the cleaning unit 8 is carried out at an electrolyte temperature of 50-60 ° C during the processing time of 1 s. The recommended operating voltage of the current source 9 is 150–170 V. A 10–2% aqueous solution of sodium sulfate is used as the electrolyte in the unit. The strip of electrolyte traces of the wire occurs in a cascade scheme as follows. Pure water is supplied only to the chamber, 5 final rinses and then P compartment is drained.6, From the whole intensification, the processor goes into the chamber J5 simultaneously with water serves compressed air. The merged final rinse water is used for the second time at the prewash stage of the wire, for which the water from compartment 6 is pumped by constant pump 14 into the jet chamber 13. As it gets dirty, the water goes to the workshop clearing through constant overflow As a lubricating medium, a soap emulsion is used, which is applied in a bath 16 by immersing the wire in a 1.5% aqueous solution of a lithium or potassium soap with temperature. The lubricant is dried by heating the wire to 200 250 ° C with a passing current when it moves through the roller contacting elements of the drying device 18. Carrying the soap emulsion onto the surface of the welding wire prevents it from corrosion, eliminates sticking of the coils, and reduces the pull force of the welding equipment through the guide channels. In addition, the application of a small amount of alkali metal salts leads to the activation of the wire and steady burning of the welding arc. When passing sections of bipolar blocks, the wire is alternately subjected to two processing modes: electrolytic cavitation in section 2 | (cathode polarization of wire); 5 electroplating section 22 (anodic polarization of the wire). With the passage of dissociated sodium sulfate by the current, an explosive destruction and removal of an oil film from the surface of the wire due to the abundant loosening of hydrogen bubbles and hydrodynamic phenomena, which take place during the cavitation of electrolyte, occurs in the cathode section. the cathode section, where it is removed as a foam product through a permanent overflow into the window 25, here and there. By removing oil contaminants, the cathode section performs the function of a current transfer cell of the relative anode section 22, the main purpose of which is to remove the film formed on the surface of the wire after cathodic cleaning. The process of electrolytic plasma treatment is characterized by the localization of the energy of the electric field in the treatment zone of the product and the appearance of a pulsed electrical discharge — at the metal-electrolyte interface. Discharge phenomena are accompanied by the formation of a stable gas layer around the product caused by the ionization of atoms, especially in the presence of easily ionized alkali metal atoms. Due to the high temperature of the anodic process (t5l200 ° C), the appearance of impurities of ballast gases of nitrogen, carbon dioxide, oxygen, and water is eliminated vapor and, hence, the formation of an oxide film on the surface of the article. Studies have shown that the electrolytic-plasma process in the anode mode in an aqueous solution of Nag SO / is characterized by voltage pulsation in the cleaning zone. This pulsation is effective in completely removing the oxide film. These features of electrolytic-plasma treatment are a positive point, as they are consistent with the requirements for the quality of cleaning the welding wire, especially precision. Studies on cleaning the surface of the welding wire have shown that the creation of the most optimal processing conditions is provided by two bipolar blocks, while the geometrical parameters of the electrodes and the electrode distance of each block section must satisfy the condition: b, (2.5-4) b; yA (2-3,5) DK, where LJ; and LD are the lengths of the cathode and anode section, respectively. D.A. and & K, respectively, the interelectrode distances in the anode and cathode section. During the operation of the unit, in the sections of bipolar blocks, an intense heating of the electrolyte with a passing current occurs, which necessitates its continuous cooling in order to maintain the desired downslope characteristics. Due to the proposed tank design, the cooling effect of the electrolyte is further enhanced by the selection of its temperature by fins on the outer surface of the electrolyte compartment. The presence of a heat insulating layer in the water compartment stabilizes the conditions for maintaining the set temperatures of the wash water and the soap emulsion, and also protects them from being cooled by the environment. The range of wire to be machined in an aggregate is distinguished by a wide variety of grades and diameters. This necessitates frequent wire refilling in the cleaning unit when switching from one gauge to another, and the duration and degree of difficulty of the filling operation to a certain extent regulate the operational reliability and productivity of the unit as a whole. The presence in each of the sections of the cleaning unit from: an upwardly slit with a vertical 1Slide gate for passing the wire and making electrodes with a parabolic cross-sectional shape, ensures reliable, fairly simple and convenient wire filling in the unit. Thus, the technical and economic efficiency of the proposed unit is achieved as follows: the execution of the cleaning unit in the form of alternating treatment sections in the electrolyte-cavitation and electrolyte-plasma modes provides a high degree of cleaning the wire surface from oil pollution, oxide film and gaseous impurities which is important for obtaining high quality welds; . the use of a water-carrying device: an airless wash in a cascade water circulation scheme, intensifies the process of washing the surface of the wire from sludge soils and traces of electrolyte, and also reduces the consumption of industrial water; applying a soap emulsion to the surface of the wire increases the corrosion resistance of the wire due to the passivating effect of the lubricating medium, leads to activation of the wire, eliminates its breakage during the passage of the guide paths of the welding units, reduces the force of the feeding mechanisms to retract; The implementation of the drying device in the form of a compact electrical contact heating unit, along with high quality drying of the wire from moisture and removal of hydrogen diffusing into the metal, reduces the size and weight of the unit, resulting in the removal of traditional bulky steam or gas heaters from its composition; the use of a neutral electrolyte in the unit eliminates the use of expensive wastewater neutralization units in the auxiliary equipment. ventilation systems, reduces the consumption of chemicals, creates benefits, and provides favorable conditions for the protection of the environment and the maintenance of sanitary and hygienic work of the staff; due to the design of the circulation tank, the need to use special energy carriers in the unit for heating and cooling process solutions is eliminated, their temperature characteristics are stabilized; the presence in the site of cleaning of the valves for filling and passing the wire, reduces the time of filling operations and increases the operational reliability of the unit.

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Claims (2)

1. UNIT FOR ELECTROCHEMISTRY OF CLEAN CLEANING WIRE, containing rewinding mechanisms, knots of bipolar electrolyte-cavitation treatment with cathode and anode sections, washing and drying devices, characterized in that, in order to improve the quality of cleaning the welding wire, it is equipped with a bathtub saponification installed in front of the drying device, and the anode sections are made in the form of electrolyte plasmatrons installed in front of each cathode electrolyte-cavitation section " 2. The unit by π. 1, with the fact that the saponification bath is made in the form of a dipping chamber with side windows and a solution recirculation system from the pump;