System and method for providing surface cleaning of steel wire on apparatus used for efficient cleaning before galvanized coating

Abstract

The present invention relates to a system and method for obtaining surface cleaning of steels with the help of alkali electrolytes and electrolytic cleaning method which provides an efficient and perfect surface cleaning system which eliminates the disadvantages of the surface cleaning system used in traditional galvanize coating process.

Description

[0001] SYSTEM AND METHOD FOR PROVIDING SURFACE CLEANING OF STEEL WIRE ON APPARATUS USED FOR EFFICIENT CLEANING BEFORE GALVANIZED COATING

[0002] TECHNICAL FIELD

[0003] The present invention relates to a cleaning system and design which provides wire surface cleaning by using electrolytic method by means of pulsed and non-pulsed electrical current for steel wire; in order to eliminate all surface dirt during pre-cleaning step before galvanized coating of steel wires after cold shaping of wires which are hot rolled and which are heat treated and in order to increase wire surface quality.

[0004] PRIOR ART

[0005] Hot rolled wires and heat treated wires are frequently produced for cold forming. These wires have to show a perfect performance until they are reduced to the desired wire diameter in order to be passed through pluralities of dies together with lubricants used in the cold shaping process.

[0006] In order to provide galvanized coating of the wires, in order to purify from lubricant and surface dirt plastered onto the wire surface and in order to clean the oxide layers formed after heat treatment after reduction to the desired wire diameter, they are dipped into hydrochloric acid, sulfuric acid and phosphoric acid baths.

[0007] In this traditional method, because of the production speed of the hot dip galvanizing line, the performance of the cleaning baths is drawn upwardly in a rapid manner for providing formation of galvanized film layer. Thus, in order to be able to form a very rapid galvanizing layer, the amounts of chemicals in the pool must be increased. On the other hand, as a result of the increase of the amount of these chemicals used, a serious dirtiness occurs in the pool. This makes difficult obtaining a successful galvanizing layer and makes difficult the disposal processes of the occurring environmental wastes.

[0008] OBJECT OF THE INVENTION

[0009] As described above, even though the chemicals in the pool are increased and the bath performances are increased, a continuous and successful galvanized coating process has not been provided. The present invention eliminates the disadvantages of the traditional cleaning system in the galvanized coating processes, and relates to cleaning system and design which will completely eliminate the dirt on the steel wire surface, in order to eliminate all disadvantages in the process and to bring some additional advantages.

[0010] In accordance with a perspective of the present invention; as a result of the studies made, it is considered that the galvanized coating layer quality is very densely correlated with the surface cleaning quality.

[0011] The wires are dipped into a strong acid bath before realizing galvanized coating. By means of this method, the lubricants on the wire, the burnt soap residues and the other dirt are tried to be removed from the wire surface. However, by means of this method, as a result of increase of saturation of iron with acid in short time, as the cleaning effect is weakened, the lubricants on the cold shaped wires cannot be cleaned sufficiently within acid.

[0012] If the lubricants, the oxide layers and the other dirt cannot be cleaned, insufficient galvanized coating layer occurs. These lubricants prevent adhering of galvanize onto the steel wire surface, and this leads to disqualified end product.

[0013] The main object of the present invention is to provide galvanize coating quality with the desired quality by using a new method and new tools.

[0014] Another object of the present invention comprises cleaning of the lubricants which exist on the steel wire surface and forming the galvanized coating layer. For this reason, electrolytic cleaning method is used in the cleaning of lubricants on the wire after cold forming. In the electrolytic cleaning method, steel wires are used as cathode, and the other alkali solutions and additive substances are used as electrolyte.

[0015] Another object of the present invention comprises that the alkali solution, used as electrolyte in the surface cleaning process used before the galvanized coating layer formation process, comprises 5-30 g / L Na+ion and 2-30 g / L K+ion. Cleaning process is realized in the alkali solution where the temperature of the alkali solution temperature is lower than 85eC and where the current densities of steel wires are between 1 and 100 A / dm2and where the cleaning duration in the solution is between 1 and 50 seconds.

[0016] Another object of the present invention is that the harmful effects will be minimized since the concentration used in the present invention is 40-50% lower than the concentration used in traditional cleaning systems and the disadvantages will be eliminated formed by hydrochloric acid, sulfuric acid and phosphoric acid with high concentration used in traditional galvanizing coated method. Thus, the required cleaning cost for the galvanized coating is reduced by decreasing the amount of hydrochloric acid used when compared with the traditional cleaning system. Since the amount of the used acid decreases, the neutralization costs of the waste acid also decrease. Thus, the damage given to the environment, humans, machine and equipment by the high concentration acid used in the traditional method will be minimized.

[0017] Another object of the present invention is to provide protection of the critical values of the pre-process chemical after cleaning and before galvanizing since a more effective cleaning is realized on the wire surface and afterwards to reduce the zinc ash amount in the galvanize furnace which occurs due to residues on the surface.

[0018] Another object of the present invention is that the wire surface cleaning capability is more advantageous when compared with traditional cleaning method thanks to the electrolytic cleaning method used in the cleaning system. Thanks to this advantage, the steel wires are drawn at high speed in continuous galvanized lines and the galvanized coating production amount will also increase.

[0019] Another object of the present invention is to remove the heat treatment step, which is among the traditional galvanizing process steps depending on the mechanical characteristics of products, from the process operation.

[0020] In order to realize the abovementioned objects and the objects which are to be deducted from the detailed description below, the present invention is a cleaning system which provides cleaning of all dirt layers, which exist on the wire surface, in order to eliminate all surface dirt during pre-cleaning steps before galvanized coating of steel wires after cold shaping of wires which are hot rolled and which are heat treated, wherein the following parts are provided:

[0021] 1 - A cleaning tank where alkali solutions are used as the cleaning chemical through which the wires pass and the dirt on the wire surface is softened,

[0022] 2- A reserve tank for the continuity of the cleaning tank,

[0023] 3- A vacuum pump for cleaning the reserve tank,

[0024] 4- A brush holding apparatus for pre-cleaning before cleaning of the lubricant on the wire surface and a carbon fiber brush for preparation to the surface cleaning, 6- Rollers for guidance to the tank inlets and outlets in order for the wire, of which the surface will be cleaned, and the circular kinesis means not to be damaged,

[0025] 7- Specific number of cathode tubes where the surface cleaning is essentially realized,

[0026] 8- A cathode cover which comprises a channel which provides breaking of the contact of the cathode tube to the wire,

[0027] 9- A magnet for magnetic field and which forms circular kinesis movement which may remove the moving ions inside the cathode cover,

[0028] 10- An anode bed which is polygon adjustable for providing further contact of the anode to the wire surface,

[0029] 11- Anode bed cover which preserves the anode bed,

[0030] 12- The outer sheath which preserves the anode bed and the anode bed cover,

[0031] 13- Anode in the form of regular polygonal prisms which will provide contact to the specially designed wire,

[0032] 14- Air stripper used for not carrying liquid passage.

[0033] Said invention is cleaning tank which provides cleaning of dirt layers which exist on the surfaces of wires before the wires enter the zinc pool after cold shaping; wherein the following process steps are provided:

[0034] 1 . Cleaning by means of alkali solutions,

[0035] 2. Providing cleaning of the wire surfaces by electrolytic method by means of electrolytic method in the cleaning liquid.

[0036] The structural and characteristic properties and all advantages of the present invention will be understood in a more clear manner by means of the below mentioned figures and the detailed description written by making reference to these figures. Therefore, evaluation shall be made by taking into consideration these figures and the detailed description.

[0037] DESCRIPTION OF THE FIGURES

[0038] Figure 1 : An isometric view of the subject matter system

[0039] Figure 2: An isometric view of the depot and vacuum system used in the subject matter electrolytic cleaning tank

[0040] Figure 3: An isometric view of the anode used in the subject matter electrolytic cleaning tank Figure 4: An isometric view of the cathode tube used in the subject matter electrolytic cleaning system

[0041] Figure 5: An isometric view of the brush and the brush holding apparatus of the brushing process in the subject matter electrolytic cleaning system

[0042] REFERENCE NUMBERS

[0043] 1 : Brush holding apparatus

[0044] 2: Brush

[0045] 3: Chemical depot tank

[0046] 4: Chemical cleaning channel

[0047] 5: Cathode tube

[0048] 6: Cathode cover

[0049] 7: Magnet

[0050] 8: Anode bed

[0051] 9: Anode bed cover

[0052] 10: Outer sheath

[0053] 11 : Anode

[0054] 12: Vacuum pump

[0055] 13: Air stripper

[0056] 14: Wire

[0057] DESCRIPTION OF THE INVENTION

[0058] The wire (14) output from the wire drawing process is connected to the unwrapping unit in a wrapped manner to the rollers and is unwrapped here. The wire (14), unwrapped at the pay off unit, passes through the annealing furnace between temperatures of approximately 750- 800eC in order to reach the desired tensile strength. Again, the galvanized coating process is realized without the wire (14), output from the wire drawing process, is heat treated at the desired tensile strength. The wire (14) which exits the annealing furnace and the wire (14) which is not heat treated pass through the cooling water tank and advance towards the galvanizing process. Before the wire (14) arrives at the cooling water tank, before the cleaning process of the lubricant, the brush holding apparatus (1) is processed for precleaning and the carbon fiber brush (2) is processed for preparation for surface cleaning. The wire (14) processed with the carbon fiber brush (2) advances towards the chemical cleaning channel (4). It passes through the cathode tube (5) which exists in the chemical cleaning channel (4), and afterwards, it arrives at the part where the dirt on the surface thereof will be cleaned. In this part, the cleaning liquid is poured into the cathode tube (5) from the chemical depot tank (3) with the help of a pump. The cleaning liquid flows from the cathode cover (6), comprising slits around the periphery and which provides breaking of the contact of the cathode tube (5) to the wire, and is poured to the chemical cleaning channel (4). In the cathode cover (6), in order to increase cleaning capability, there is a magnet (7) which will form a magnetic field which forms circular kinesis movement which will move away the moving ions. After the wire (14) removes from this part, it advances to the anode (11) which exists in the chemical cleaning channel (4), and passes through an adjustable anode bed (8) in a polygonal form for providing further contact to the wire surface. Here, there is the anode bed cover (9) which preserves the anode bed (8). There is the outer sheath (10) provided in the middle of the chemical cleaning channel (4) and which preserves the anode bed (8) and the anode bed cover (9). While the wire (14) passes through the center of the anode bed (8), in order to provide better contact of the wire to the anode (11), after the wire passes through the anode which is in regular polygonal prism form which is specially designed, the wire surface occurs in a dry form with the help of air strippers (13) whose center is adjusted, and advances towards the cooling tank which is the next step. A vacuum pump (12) is used for removing the dirt accumulated in the chemical cleaning depot tank (3) after the surface cleaning of the wires. By means of this vacuum pump, it is aimed to increase the performance of alkali chemicals. The wire (14), having a surface cleaned from lubricants, passes through hydrochloric acid with very low concentration, and oxide and other dirt are removed. The wire (14) which exits the hydrochloric acid tank removes the residue liquid droplets thereon thanks to the strippers and enters the flux tank which is the final step before zinc coating. Thus, a thin film occurs on the steel wire (14) and is prevented from being oxidized until it enters the zinc furnace. The wire (14) coated with flux enters into the zinc furnace and is packaged in a galvanized coated form in the wrapper part.

[0059] INDUSTRIAL APPLICABILITY OF THE INVENTION

[0060] The efficient cleaning system and tank design, made by using electrolytic method in parts where surface cleaning is made before galvanize, has a structure which can be applied to the galvanized steel sector.

Claims

CLAIMS A cleaning system and design which provides purification of dirt from the surface of the wire (14) before galvanized coating, wherein the following parts are provided:• Pre-cleaning brush holding apparatus (1 ) and brush (2) for cleaning the lubricant on the wire (14) surface, after the wire (14) exits cold shaping,• A chemical cleaning channel (4) where the wire (14) passes through the alkali solution with low concentration and where the dirt which exists on the wire is softened,• A chemical cleaning channel (4) where the dirt which exists on the wire (14) is softened; a cathode tube (5) where the cleaning liquid passes through the chemical depot tank (3), a cathode cover (6) which provides breaking of the contact to the wire and which includes slits on the periphery thereof, a magnet (7) which will form a magnetic field which forms the circular kinesis movement which may remove moving ions for increasing cleaning capability, anode (11) which is in the form of regular polygonal prism, preferably triangular prism specially designed for providing better contact of the wire to the anode, an anode bed (8) which can be adjusted in polygonal form for providing further contact to the wire surface, an anode bed cover (9) which preserves the anode bed (8), an outer sheath (10) which preserves the anode bed and the anode bed cover, a vacuum pump (12) elements for removing the dirt accumulated in the chemical cleaning depot tank (3) after surface cleaning of the wires. The surface cleaning system and design according to claim 1 , wherein copper bar elements with flexible mesh are provided which are assembled to the inner part of the chemical cleaning channel (4) and a power supply is provided for forming direct current which operates these copper bar elements. The surface cleaning system and design according to claim 1 , wherein in the chemical cleaning channel (4), alkali cleaning liquid is provided which can function in the most efficient manner with cathode and anode. The surface cleaning system and design according to claim 1 , wherein the system comprises a vacuumed pump for preventing becoming dirty of the cleaning liquid used in the chemical cleaning channel (4).

75. The surface cleaning system and design according to claim 1 , wherein design is provided which will provide assembly and dismantling easiness of all parts, which will form the system, into the chemical cleaning channel (4).

6. The surface cleaning system and design according to claim 1 , wherein the current density, to be used in increasing wire surface quality and in eliminating all surface dirt prior to galvanizing realized with the use of alkali cleaning liquid by using electrolytic method with pulsed and non-pulsed electrical current of steel wire with the help of the tools mentioned in claims 2 and 3, is between 1 and 100 A / dm2and the electrolysis duration is between 1 and 50 seconds.

7. The surface cleaning system and design according to claim 1 , wherein in the alkali cleaning liquid dependent on claim 3, 5-30 g / L Na+ion and 1 -30 g / L K+ion are provided.

8. The surface cleaning system and design according to claim 1 , wherein the process temperature of the alkali cleaning liquid dependent on claim 8 is 85eC or at a lower temperature.8

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