EP1022361A2 - Process for cleaning metals after their thermal treatment - Google Patents

Abstract

The appts. includes a pad which is made of an insulating fabric, and is placed between the electrode (10) and the metal (8) to be cleaned. It also includes a low-voltage alternating current source (2) which is connected to the metal (7) by means of the other electrode. The pad taking the form of a tubular sock (12) or a strip with a thickness of more than 1 mm is impregnated with an acid solution (18). The pad is made of a polyether ether ketone fabric with improved insulating properties.

Description

The invention relates to: a device for cleaning of metals after their processing at high temperatures, i.e. a device with which the oxidations, Stains or other appearances that are machining high temperatures such as welding and laser or plasma cutting of metals on their surface can be eliminated.

The current state of the art knows a device which consists of a plug made of glass fiber fabric, which is wrapped around the end of a beak-shaped electrode is. This stopper comes with an acidic solution based on phosphoric acid (81% by weight) and quinoline (0.01% by weight) and water and then near the surface to be machined appropriate. It is also an AC power source and low voltage available, one of which has a conductor the mass of the workpiece and its other conductor with the Metal body of the plug holder is connected. Thereby the conditions of an electrolytic arise in the solution Cell that quickly removes the oxide or stains away.

In the system just described, however, the activity of the user is frequently disrupted by technical disadvantages which result from frequent maintenance and the frequent replacement of the insulating material made of glass fiber, since this burns due to the high heat development to which it is exposed or because it is in the tissue accumulate large quantities of dirt that prevent the development of suitable electrical conditions, and since this stopper often has to be soaked with the acidic solution. Becomes
if the device is not sufficiently impregnated, this leads to mechanical damage to the tissue and to a reduction in the electrolytic action.

In addition, the dissolved residues remain firmly on the treated surface that this washed several times must be before it can be finally dried.

In addition, the acidic solution has one based on its characteristics very high density, which is also required so them when they are on vertical surfaces to be treated or is applied to surfaces on the underside, not to the Operator drips down or runs down the wall.

In addition, it is not very practical for the operator if he has a container of acid solution and a large amount on fiberglass insulating fabric, with which he the electrode beak has to wrap around, stand next to it, which makes the work not continuously and therefore not very productive as well as sometimes dangerous.

The current state of the art also knows devices for Cleaning metals with thin acid solutions - on the basis of citric acid - that of the plug constantly by means of an electro submersible pump installed in the acid container is fed. Because of the low power and the The above-mentioned was made less aggressive by the acidic solution However, the device is never industrial on a larger scale applied.

In addition, the one through which the electricity flows and the other Plump the surrounding electrode on as it is not just a good one electrical conductor, but also a good heat conductor is: The one in this way due to the jam from the plug A rise in temperature that can be observed leads to a rapid evaporation of the acidic solution mentioned, so that it also leads to an undesired combustion of this plug can come, which in turn creates a short circuit between the electrode and the surface to be cleaned. Therefore, the plug must be replaced relatively often.

Finally, none of the previously known devices sees protection of the operator from during cleaning vapors occurring.

This prior art can be used in several ways can be improved to eliminate the above-mentioned disadvantages and to make the device safer and easier to use to design as well as a longer life to achieve the graft.

The need for one arises from what has been said Solution to the technical problem, which is the To redesign the device and a new application of the electrolytic function to remove oxides, oxidations and spots of metals as well as the electrode and structurally transform the plug so that the above Symptoms of burns can be avoided.

With the invention, the above-mentioned technical problem solved by using the following device: device for cleaning metals with a plug Insulating material between the electrode and the to cleaning metal is brought, an AC power source with low voltage connected to the other electrode on the Metal is connected with an acidic solution with which the plug is soaked, the plug coming from a tubular stocking or from an insulating material fabric tape with a thickness of more than 1 mm, thereby characterized in that the material for insulating the electrode has been improved; the plug is made of polyetheretherketone fabric (Trade name PEEK from Hoechst), and with it becomes the metal end of the beak-shaped electrode wrapped around.

In addition: The above-mentioned fabric made of polyether ether ketone can also be used in the form of a felt.

In addition: The above-mentioned fabric made of polyether ether ketone can also be used in the form of a network, with a layer of felt made of any heat-resistant material Insulating material is coated, this Layer applied later or directly during production can be provided.

In addition: The above-mentioned fabric made of polyether ether ketone can be coated with a layer of felt, wherein this felt can also consist of polyether ether ketone.

In addition: The layer of felt mentioned is placed on the Beak covered the outside of the fabric layer made of polyether ether ketone upset.

In addition: a device for cleaning metals with a plug of insulating material between the Electrode and the metal to be cleaned is used, a low voltage AC source using the other electrode is connected to the metal, one acidic solution with which the plug is soaked, whereby the plug out of a tubular stocking or out an insulating material tape with a thickness of more than 1 mm, characterized in that the device, to make their operations more secure, slots on the electrode in the vicinity of said plug, which are connected to a suction fan that the Sucks off gases and vapors generated during processing.

In addition: an acid supply circuit in which the high density and strongly aggressive acid using a hand pump or in another way from the acid tank, which is made of insulating material exists or isolated from the environment is sucked in.

In addition: a metal beak becomes inside the plug - hollow or with axial bore - provided, through which the acid is promoted and which on the end the electrode is mounted.

In addition: The above beak is made of fabric Surround insulating material that is handled so that two parts are created, with a ring made of elastic, insulating or shrinking hardening material attached or held; this elastic or insulating Ring can be turned over after the plug Tissue was replaced, reused several times become.

In addition: The above beak can be made of a metal body and a replaceable end made of insulating material consist of at least one metal body inside located on the end face of the beak ends and the electrolytic action is activated.

On top of that: the interchangeable end of the beak Made of metal material is on the side walls with insulating material coated so that in the contact area with the Beak body and electrical on the non-insulated end face Consistency is given. This end face is with holes through which the acidic solution is passed becomes.

In addition: The insulation coating mentioned consists of a Teflon film with a thickness of 0.1 - 0.3 mm for Protection against short circuits and from 0.6 - 1.2 mm for thermal Insulation.

Finally there is: as a material for the beak, i.e. for both the body and the interchangeable Metal end, high-strength stainless steel can be selected. As high-strength stainless steel for the exchangeable metal end steel grade AISI 316 should preferably be used.

This invention offers the following advantages: The supply with acid is done directly by the operator and such often this is required; doing this can also be a very aggressive Solution are used, the loss of time for soaking the graft and no acid more when transporting from the container to the processing point can get lost. The plug gets better with acid soaked and thus heats up less or wears out less due to thermomechanical stress. The beak of the electrode can be of various shapes have, depending on the respective processing position judge; the beak is cone-shaped, the stocking can be changed more quickly. The Avoids feeding the acidic solution inside the plug, that acid is spilled or not to be cleaned Parts arrived. Because of the less concentrated Acid, through its higher fluidity and through the better suitability for removing treatment residues with a simple washing process makes the treatment more efficient and can be used for large-scale productions be, with a cost advantage over the known Technology results.

The life of the stocking, even if it is made of glass fiber is that the end of the electrode Insulating material, or if it is made of metal, in that it has a thick layer of insulating material is coated compared to the short lifespan essential for an electrode made entirely of metal improved.

A maximum lifespan can be achieved by using a double-layered plug, one on the inside Layer of fabric and a layer of felt on the outside, can be achieved: With the inside tissue it can are polyether ether ketone.

With the polyetheretherketone fabric you can achieve the highest durability values achieve because it has a very high resistance against heating and acids. The outer Felt layer of any suitable material, such as that The aforementioned glass fiber holds the solution at the cleaning point and enables adaptation to the workpiece shape, which greatly increases the life of the stocking.

By using stockings with a double layer of polyetheretherketone, i.e. for both the fabric and for the felt, can achieve maximum performance in terms of service life, Work precision and quantity can be achieved.

Given the high material wear on the active The beak end allows the fact that the beak end is interchangeable, the beak body from ordinary Stainless steel to manufacture, whereas the end from special stainless steel can be manufactured, which is more expensive, but wears out less quickly. It follows from this an improvement in the efficiency of the cleaning process.

Figure 1 provides an overall view of the device with acid supply and sock made of insulating material fabric Figure 2 is an enlarged view of the with the stocking-wrapped beak of the plug. Illustration 3 shows the hydraulic diagram of the pump, which is the acidic solution sucks. Figure 4 is the hydraulic / pneumatic diagram the pump that blows the air into the acid tank, whereby the acidic solution is applied. Figure 5 represents the cut through a beak with a truncated cone Metal insert and sock made from improved insulating material Figure 6 is the section VI-VI through the frustoconical insert. Figure 7 shows that suction of gases and vapors according to the invention, which are formed by heating the acidic solution, and their precipitation in the wet process. Figure 8 is a Partial outline of a pistol with improved interchangeable Beak with plug connection, which adapts to the enables each working position. In Figure 9 is the improved beak shown with the stocking is wrapped from insulating material. Figure 10 is one back outline view of the improved beak, on of the lines running inside are. Figure 11 is an outline view of the front this beak. Figures 12 and 13 show the views two beaks used for the treatment of heavy accessible places are trained. Figure 14 is the view of a beak with a brush made of insulating material for the treatment of hard to reach places. Figure 15 is the outline view of the electrode, its end is carried out according to the invention with insulating material. Figure 16 is the enlarged section through a longitudinal plane the beak of the electrode. Figure 17 is the View of a beak with a brush made of insulating material for the treatment of hard to reach places. Illustration 18 shows the section F-F through the enlarged illustration 17 limited to two of the filamentous tubes. Figure 19 is an outline view of a plug made of a double layer of special material for wrapping of the beak. Figure 20 represents the end of the beak where the plug is wrapped with the double layer is. Figure 21 is the outline view of a metal beak with interchangeable end, which is screwed on Body is attached and with a thick layer of insulation is covered.

It shows: with 1, Figure 1, the electrical Supply device consisting of a transformer 2 for converting mains voltage to low voltage, a selector switch 3 for regulating the output voltage, two terminals 4 for conductors 5 and 6, from which one by means of pliers 9 to the body 7 of the treating surface 8 and the other to the body 10 the electrode, which ends with the beak 11, which in turn is surrounded by the stocking 12 which is clamped by the clamp 13 is held, is connected; at 14 a small pipe for supplying the acidic solution inside or outside the insulating handle 15, the acidic solution using a pump 16 from the tank 17, which contains the acidic solution 18 and is insulated from the rest of the device becomes; at 19 the gas cap with ventilation; with 20, illustration 2, the piece of stocking made of insulating material fabric, with which the beak 11 and the end of the body 10 of the Electrode is wrapped; at 21 on the beak tip bent stocking held by the clamp 13; With 22 a pump that compresses the air in the tank 23 and Generates pressure that causes the acidic solution 18 in the Tube 14 flows; at 24 a check valve; at 25 a shut-off valve in the aforementioned tube 14, which in the Is attached near the plug handle.

Also shown: at 26, Figure 5, the end of the Electrode with the frustoconical portion 27, in the a hollow beak 28 is inserted, which also with a frustoconical end 29 is provided which by the longitudinal section 30 is made flexible; at 31 the inside Pipe through which the acidic solution is passed and that with the seal 32 at the said end of the electrode is mounted and near the axial slot 33 ends; with 34 that with a ring 35 made of elastic material or from hardening shrink material on said hollow beak attached insulating fabric; at 36, Figure 7, suction slots provided near the beak the gases generated during operation and Fumes; with 37 the anatomical handle with push button 38 for Actuation of the pump 16 or the valve 25; at 39 a Hose for the extraction of the gases or vapors mentioned is connected to a centrifugal fan 40 which the Gases passes into a suitable moisture filter 41, whereupon the gases emerge cleaned from the opening 42; at 43 the tube in which the acidic solution is passed, and at 44 the electrical conductor, possibly with a pair of wires to operate the pump 16, provided that it is an electric pump trained, equipped.

Also shown: at 45, Figure 8, a standardized Handle with curved electrode body 46, operating button 47, similar to the push button 38; with 48 of Beak with bayonet lock, consisting of the slots 49 of the closure, from a first section 50 and from a second, slightly conical section 51 and finally, from a tapered beak 52 that with the end 53 of the hole for supply with acid solution ends; at 54 the stocking from the open at the beak and at the ends 56 and 57 by the clamp 58 or insulating material fabric fastened by an elastic element 55; at 59, Figure 10, the mentioned hole for Supply of acid solution in the pre-bore 60 is tightly connected to the electrode 46 and in which the Solution flows; at 61, Figure 12, a flattening of the Beak 52 to the part of the open stocking it 54 with three times the strength and thus smaller recesses to be able to achieve; at 62, Figure 13, a pointed and angled beak for the treatment of pointed inner corners; at 63, Figure 14, a thin, himself tapered beak with a fine brush 64 with stiffened Bristles 65 made of insulating material: the bore 59 directs the acidic solution into the middle of this brush.

Also shown: at 71, Figure 15, the body of the tapered metal beak that holds the electrode represents; at 72 the end of this beak made of insulating material with a bore 73 for supplying the acidic solution to the stocking that represents the plug and the clarity is not shown for the sake of; with 74 of Head of the screws for attachment to this body, the attached near the end face S: the shaft these screws extend into the corresponding threaded hole 75, Figure 16; at 76 the hole over which the acidic solution is passed into said body; at 77 the contact surfaces between the body 71 and the end 72: due to the sufficient flexibility of the used Material, i.e. glass fiber reinforced Teflon, none Seals used. If there are any leaks, these are characterized by the stocking, not shown Isoliermaterialgewebe caught, the said electrode completely surrounds.

Also shown: at 78, Figure 17, the body the electrode with a brush with tubes of insulating material 79; at 80 the hole through which the acidic solution is conveyed into the chamber 81, which is in the metal head 82nd of the brush into which the said tubes are inserted are located; at 83, Figure 18, the holding block of the said tube of insulating material. In the picture only two tubes are shown, expediently however, these should cover the entire area of said head cover; at 84 the drilling of these tubes over which the acidic solution from the aforementioned chamber 81 into the cleaning metal bulge.

Finally are shown: with 91, Figure 19, the Plugs, consisting of an insulating material fabric layer 92, preferably made of polyether ether ketone, and one Insulating material layer made of felt 93; with P the width of the plug strip, which is larger than the width of the Beak for which the plug is intended; with 94, illustration 20, the end of the beak seen from the side, around which the two sides of the plug of the previous one Figure are wrapped with the fabric layer 92 inside and the felt layer 93 is laid outside; at 95 the hole, through which the acidic solution is passed; at 96 one Mounting ring made of insulating material, which the plug 91 holds on said beak 94; at 97 a metal beak with a replaceable metal end 98, which by means of Screws 99 are attached to this beak; With 100 the insulating coating of the replaceable end, the can also be more strongly trained; at 101 the thinner Coating on the body of said beak 97 for Protection against short circuits; at 102 the metal surface the largest by the electrolytic cleaning action There is metal wear; at 103 the well for production the acidic solution.

In the device for electrolytic cleaning of Metal surfaces become an acidic solution with relatively low levels Proportions of phosphoric acid (52.5 percent by weight) and quinoline (0.01 percent by weight) used in water: Due to in contrast to the thin liquid of this acidic solution to the high density of the previously used solution Smaller amounts of solution required, which are directly inside the stocking plug 12 or 54 or the plug 34 of the hollow beak 28 are directed, causing the dripping from solution to surrounding surfaces is avoided and relatively few and easily washable after cleaning Surfaces result, which represents a cost advantage.

This solution is then continuously promoted so that the plug 12, 34 or 54 is constantly soaked. The electrolytic action of the acid solution flowing through it Stroms is always constant since the operator does the work doesn't have to stop to wet the plug, but only the push button 25, 38 or 47 for supply with the solution on the handle 37, 45 must operate.

The hydraulic circuit shown in Figure 3 works with a pump 16, both as a manual pump be trained and operated directly by the operator can, this direct operation using both a Suction-pressure bulb as well as electrically with low voltage can be done: In the case of one that works with air pressure The tanks 17 or 27 are made of insulating material perform that from the moment the acidic Solution is introduced through the electrode into the The interior of the tank is under tension because the acid column in the tube the voltage leads to the tank. That way it works the pneumatic-hydraulic shown in Figure 4 Circuit also with a manual pump 22 that the Tank 23 pressurized, and the further the solution by opening the valve 25 to the beak, the more the pressure in the tank drops, causing a new one Pressure generation by means of the pump 22 mentioned is. Maintaining pressure can be automatic done by a pressure switch, not shown, the detects the pressure inside the above tank.

The tubular stocking 12, 54 made of insulating material fabric is mounted by the first end 20, 56 on the Beak 11, 52 is inserted until it is completely envelops. The stocking is twice the length, so that it turns over can be, the other end 21, 57 exactly comes to rest on the first end. The clamp 13, 58 is placed so that both ends open simultaneously the body of the beak 11, 48 fixed.

Analog, but easier to assemble or replace of the hollow beak 28, which is pre-assembled with a stable Isoliermaterialgeweb 34 is provided. This The beak must have a frustoconical end 29 the frustoconical part 27 of the end 26 of the electrode be snapped on. The replacement takes place analogously by said beak completely removed and another Beak is mounted. The hollow beak with a truncated cone Snap lock can come in different shapes be trained, as with the beaks in the figures 12 and 13 can be seen or with a brush as in the illustration 14 shown.

The beaks with snap lock close between the Pre-bore 60 and the bent electrode 46 close to to avoid leakage of acidic solution, so that this is completely directed to the supply bore 59. By the flattened shape 61 shown in Figure 12 can the beak so with the folded over the flat tubular stockings that are essential less strength than normal Beak 48. Finally, it allows the pointy and angled Version 62 of the beak, depressions and to reach pointed inner corners with limited space to which otherwise it’s not easy to get to.

In addition, the beaks can be used instead of a snap connection be formed with a screw connection.

The one with a brush 64 with bristles made of insulating material 65 executed beak 63 is used by in Moved lengthwise or crosswise to the application angle weld is, which with a top layer of Teflon or Another similar material stiffened the bristles Bottom of the cavity between the wall and the weld can reach and clean it completely.

The gun with the slots 36 for aspirating the gases and vapors enables the operator to be completely safe Work. The extracted air, the gases and vapors contains, is passed through the wet filter 41, each after the treatment of metal surfaces by treatment is designed with products used with acid.

In operation, end 72 does not conduct electrical Electricity but this is done through the heads of the screws 74, which are installed so that they are parallel to the end surface S of this end. The current is from these Screw heads on the soaked with acid solution Stocking passed through, causing the electrolytic cleaning action arises. Since the end 72 is non-conductive, it warms not by the electrolytic action that the Exerts stocking on the surface to be cleaned, and consequently, the stocking is not sustainable through burns damaged.

The operation of the electrode with body 78 with a brush tubes 79 made of insulating material result from that electric current in the acidic solution from said Metal body 78 to the surface of the cavity to be cleaned is directed, including the innermost areas of this Excavation can be achieved.

Tests in which the end of the electrode is reinforced with glass fiber Teflon has been made essential result in a longer life of the stocking than with conventional stockings on completely metallic ends, the magnitude of the improvement being about one Working shift is.

The one with double-layer fabric 92, 93, the outer Layer consists of felt 93, improved plug 91 will put on by wrapping the end of the beak and the stopper is fixed with a mounting ring 96. On the Side plug of the end does not necessarily have to be a stopper have perfect overlap, but the middle part this plug must be the active surface 102 of the metallic Cover 98 at the end, since it is preferably a Teflon film Insulating coating with a thickness of 0.6 - 1.2 mm 100 an electrolytic action on the flanks in the end avoids, whereas the completely uncoated Page 102 of the promotion is fully suspended. The end can, even if this is less recommended, only with a thin layer of insulating material, for example one Teflon film can be coated with 0.1 - 0.3 mm thickness, the it also prevents damage and short circuits on the flanks protects how that for the body of the beak 97 with the Coating 101 is the case.

Even if for the two layers 92, 93 of the above Plug different insulation materials used is then for the double layer plug 91 achieves maximum lifespan when in the inner fabric layer 92 polyetheretherketone and in the outer Layer 93 uses a felt based on polyether ether ketone becomes. The double layer tape can be made are connected by the two layers afterwards or by adding a layer directly during manufacture is applied to the other.

The worn plug can be easily replaced, by removing the mounting ring 96 and the band is replaced at the end of the beak. The ring 96 made of insulating material can be used multiple times.

After that with a thick or less thick Insulated layer 100 worn metallic ends 98 worn and the cleaning function is no longer like can provide desired, it is by removing the Screws 99 replaced.

The highest service life values for the metallic beak end are achieved by AISI 316 stainless steel; for all other stainless steels, the costs are less, but the wear is also greater.

With the current state of the art, this was technical Problem of wear of the electrode due to the low benefits not. With these devices could however, only very low efficiencies are achieved become.

Claims (15)

Device for cleaning metals after their processing at high temperatures with a plug of insulating material which is inserted between the electrode (10) and the metal to be cleaned (8), a low-voltage alternating current source (2) which is connected to the other electrode (9) is connected to the metal (7), an acidic solution with which the plug is impregnated, the plug consisting of a tubular stocking (12) or a band (34, 91) of insulating material fabric with a thickness of more than 1 mm , characterized in that the plug is made of an improved electrode insulating material, ie polyether ether ketone fabric, with which the metal end of the beak of the electrode is surrounded. Device for cleaning metals according to the im preceding claim, characterized in that said Polyetheretherketone fabric is formed as a felt. Device for cleaning metals according to the im The preceding claim 11, characterized in that the said fabric (92) made of polyether ether ketone with a Felt layer (93) made of any heat resistant insulating material is provided, either retrospectively or directly is applied during manufacture. Device for cleaning metals according to the above Claim, characterized in that said Fabrics made of polyether ether ketone are also available as a mesh can, which is covered with a layer of felt, wherein this felt layer consists of polyether ether ketone. Device for cleaning metals according to one of the preceding claims 3 or 4, characterized in that said layer is formed as a felt (93), the one on the outside opposite the beak (94) Part of the fabric layer (92) made of polyether ether ketone located. Device for cleaning metals after processing them at high temperatures, according to one of the above Claims 1, 2, 3, 4 or 5, with a plug Isoliermaterialgewebens between the electrode (10) and the metal (8) to be cleaned is used, an AC power source with low voltage (2) with the other Electrode (9) to which the metal (7) is connected, one acidic solution with which the plug is soaked, whereby the plug from a tubular stocking (12) or from a band (34, 91) made of insulating material fabric with a Thickness of more than 1 mm, characterized in that that the device to make its operation safer with slots (36) on the electrode (26, 46) in the Near the said plug (12, 34, 54) is provided, the are connected to a suction fan (40), which during evacuates the resulting gases and vapors. Device for cleaning metals according to the above Claim 6, characterized in that in the Device high density and strongly aggressive acid used comes and that a circle (14) for supply with acidic solution is provided, in which the acid by means of a hand pump (16) or in another way from a Tank (17) containing the solution (18) is sucked in, the tank is made of insulating material or opposite the environment is isolated. Device for cleaning metals according to the above Claim 6, characterized in that inside of the plug a metal beak - hollow (28) or with axial bore (52, 59, 60, 76, 95, 103) - is provided by which the acidic solution is promoted and which is mounted on the end of the electrode. Device for cleaning metals according to the above Claim 6, characterized in that the the above beak with a fabric made of insulating material surrounded so that two parts (34, 91), and with a ring (35, 96) made of elastic, insulating or shrinking hardening material attached or held; this elastic or insulating Ring can be turned over after the plug Tissue was replaced, reused several times become. Device for cleaning metals according to a of the preceding claims 6 or 9, characterized in that that the above beak from a metal body (71) and a replaceable end made of insulating material (72) there is at least one metal body inside (74) located near the end face (S) of the beak ends and the electrolytic action is activated. Device for cleaning metals according to the above Claim, characterized in that it the above interchangeable end (94, 98) of the beak (97) made of metallic material, which on the side walls is coated with insulating material (100), so that in the contact area with the beak body and on the non-insulated end face (102) electrical continuity given is. This end face is with holes (103) provided, through which the acidic solution is passed. Device for cleaning metals according to the above Claim, characterized in that the device has the above-mentioned insulating coating, that from a Teflon film with a thickness of 0.1 - 0.3 mm (101) to protect against short circuits. Device for cleaning metals according to the above Claim, characterized in that the device has the above-mentioned insulating coating, that from a Teflon film with a thickness of 0.6 - 1.2 mm (100) for thermal insulation. Device for cleaning metals according to a of the preceding claims 10 or 11, characterized in that that the material from which the beak, i.e. both the body and the interchangeable end, is high-strength stainless steel. Device for cleaning metals according to the above Claim 14, characterized in that as Material for the replaceable end of high-strength steel Grade AISI 316 was chosen.

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