In order to improve the product quality and productivity, lower energy consumption, now cable industry gradually continuous annealing mode instead of the original tank annealing. Continuous annealing working principle is to use a certain length of copper wire the two positive and negative electrode copper wheel directly short circuit, because the resistance of the copper wire is quite low and in low voltage condition can also produce a lot of short circuit current. Use this low voltage large current, can achieve the copper wire burning soft purpose. In the field operation, can cause annealed wire diameter necked, surface scratch, red copper wire, copper wire color, copper wire oxidation and so on some phenomenon. According to phenomenon, combined with annealing principle to explain and solve operational some mistakes.
When annealed wire diameter necking: copper wire in hard state, export module is sizing die, tension size not the wire diameter wire drawing. But in the continuous annealing, copper wire heating make wire become soft, line itself has certain extension. In order to put the line extended part timely send out, and not the copper wheel of conductive nickel ring friction tank, Middle Drawing Machine with Annealer generally combined with foreign advanced experience into triangular annealing structure. Triangular structure of the outer conductive copper wheel points inside and outside two groove, the copper wire inside groove introduced, complete annealing. From the ditch derivation to accept line. In order not to make nickel ring up tank, outside groove diameter ratio inside groove is big, this on the structure solved the nickel ring grooving problem. To compensate for annealed wire diameter necking problem. General continuous annealing export should choose to die than actual need wire diameter 0.0015-0.0035 more appropriate. More than just part of the natural extension off.
Because after annealing line is very soft, corresponding to different wire diameter to use appropriate tension weight, if wire diameter small tension is big, will be the wire diameter and thin. Tension control in annealing demand is very high. Not any line with a tension.
Surface scratch: continuous annealing is the use of copper wire in conductive wheel on continuous contact eduction, to complete the positive and negative electrode short circuit, achieve annealing purpose. In theory copper wire and copper round there is relative motion between, will produce a certain scratches, and furthermore, line in copper wheel is the process of continuous electric shock. Fine line because the contact area is small, the look is not very obvious, thick line for large contact area, appears to be more obvious. produced scratches, one to make cooling water have certain lubrication, (suggest using burn stew oil, according to the concentration of 0.1% add or directly use contain certain antioxidant function drawing oil, press 1-3% concentration add) reduce the wire and the electric conduction of the friction between the wheel. Second, we need to be in the copper wire fine-drawn cases try to increase the tension, let the line and conductive wheel slip between reduced, minimize bruises. Three is to examine each thread guide roller, porcelain hole, etc have damaged coarse bad place. control annealing part, in the annealing into terminal adding tension frame, annealing parts constitute the independent PID closed-loop control, this would solve the host and annealing part for wire diameter difference slip, solve the host and annealing between the slip, let copper and nickel belt for slip between caused by electric shock point down to a minimum.
After annealing copper red: continuous annealing three sections: preheating section, the work piece, cooling section. Preheating section for line length is longer, the temperature is not more than 250 degrees, and not let the discoloration of copper wire. Work period of current is big, copper wire high temperature (550 degrees), if the working section has air exist, copper and oxygen in heating conditions produce copper oxide. In this section of the most easy oxidation is red. Work period of it is to use steam (or water) protection, if steam enough (or water level is too low), in this section will have the red. The solution is to increase a steam (or improve water level). The other is to make the water level of the bronze wheels to improve, guaranteed that the work period there is no air.
Note: using steam protection occasions, cooling water can't more than steam outlet, or steam into direct heating cycle cooling water, so that can absorb a large number of steam, steam pressure to zero (steam generator heating lamp display, says it has been heating, steam pressure is zero. A lot of times can make the person produces steam generator heating pipe burn or steam generator power not enough illusion, in the process of production should pay attention to this phenomenon, so as not to be misled. Work DuanRuGuo didn't steam protection, copper wire them will change color. The solution is appropriate adjustment small cooling water feed water pressure. Don't be too big. At the same time to ensure that the water back to the opening place has certain pressure, can't let air come in from the back gate.
Copper wire color (dark red or white) : continuous annealing in the work period of the line burn soft and pass cooling section after cooling can achieve lead not hot, without water. In order to solve large size line continuous annealing cooling is not enough, lead is too hot, resulting in copper wire dark red or white, in cooling section has two inlet: cooling down water, cooling water. Doing small specification line, as long as the cooling water open it. If do big specification line, two outlet open, so that strengthen the cooling effect of the copper wire. Lead is not too hot, also is not easy to have a dark red or white with. specifications larger copper wire, because before is steam to protect annealing, working section and cooling section is a communicating vessels, such cooling section water could not higher than the steam inlet position, or water to steam mouth stopped, but cooling section water level is not high, also cannot have a good cooling effect. Really contradictory things. In order to solve this problem, we improve the annealing design, fundamentally solve this contradiction. According to the different wire diameter, literally adjust cooling section water level, to achieve the purpose of cooling.
Copper wire color: two kinds of circumstances, one kind is copper wire annealing them will change color, still have a kind of is annealing out at that time is very good, but not as long as you keep oxidation color.
In the former case, mainly pay attention to work in period without air, the solution as above. There is water too dirty or water quality change bad, need to replace clean water. The 2nd kind of circumstance is usually caused by with water, mainly is to solve the problem of dry. If air blow not stem, consider adding a wiper die to solve, the effect is very good also. Let the copper wire out without water is the final purpose of solving.
Note: for drawing with continuous annealing, in operation should pay attention to things more, a link to pay no attention to, it can come production of trouble, the scene is more than just introduced the typical fault cases, in the actual production, in order to solve the hidden danger source will occur, in the peripheral equipment with the attention should be paid to some:
1: The wire drawing oil tank volume can not less than 7 cubic/table, pull cooling oil pool not less than 3 cubic/station, oil pool in length and width as far as possible, don't be too deep, that is beneficial to the heat dissipation.
2: Copper wire in the annealing process of heat all let cooling water away, so that cooling water will continuous heating, when the cooling water temperature over 70 degrees, the cooling effect is not ideal, copper wire will be red. So cooling pool cannot too small, cooling water must also be enough, suggest cooling pump motor selection three-phase 0.75 KW above, outlet diameter in 1 "self-priming pump. Don't suggest using single phase water pump. Pipeline laying in the elbow less as far as possible, to ensure that the water flow and pressure.
3: High speed wire drawing machine mould and equipment to reduce surface rate consistent with. With too much better boot, but cone life will be cut short.3. The die of the high-speed wire drawing machine should be consistent with the reduction rate of the equipment. It is better to start the machine if it is too large, but the life of the tower wheel will be reduced. If the matching is too small, it is difficult to draw the wire, and the wire will be easily broken when the speed is fast, but because of the small slip, the tower wheel is not easy to groove. According to on-site experience, it is sufficient to add 2-3 sliding coefficients on the basis of the reduction ratio of the equipment on the general mold ratio. The high-speed wire drawing die requires that the sizing area be shorter than that of the soil wire drawing machine, and the bell mouth should be rounded. If the sizing area is longer, the mold life will be longer, but the compression area is longer, and the corresponding line speed cannot be added up. The high speed is especially easy to break. For the wire drawing machine, polycrystalline is generally used for bridge molds, and diamonds are used for export molds because they are fixed-diameter molds. It is best to use diamonds in the last few three or four molds close to the exit mold. There are also many domestic molds with stable quality. Tianchang and Hebei molds can also be used, the price is relatively low, and the price is very high.
4. The quality of copper materials is the most difficult to find in this regard. Generally, it is often inexplicably broken. Both large and small specifications are similar, which brings the biggest headache to front-line workers. And there is no reason to find out. Only after replacing several batches of busbars, can we sum up experience. Our manufacturers are also powerless.
5: The problem of threading method, in order to reduce the linear slip coefficient on the tower wheel, try to make as many circles on the tower wheel as possible. Generally, the circle on the tower wheel cannot be less than 4 circles. If there are fewer circles, the tower wheel is easier to groove. . Too many laps is not good, and it is easy to press each other.
5. The problem of tension and air pressure adjustment. Under normal circumstances, the greater the tension and air pressure when not annealing, the better, as long as it is not too large to break the wire. Because of the dual frequency conversion control, the speed of the winding frequency conversion is mainly based on the precision potentiometer behind the tension rod and the intermediate voltage to obtain the balance of the winding and unwinding. If the tension air pressure does not reach the required air pressure value for the wire diameter specification, it will cause the winding wire When the speed is slow, the slippage becomes larger. When the customer does not respond to annealing, the copper wire will burn red after the machine speed reaches 1300M/MIN. This is a typical tension and air pressure that is too low, resulting in a fast host speed and a serious shortage of wire take-up speed. The copper wire rubs on the fixed speed wheel of the main engine to generate a lot of heat, and the copper wire is annealed. If this happens, the customer's host fixed-speed wheel will groove (generally, the fixed-speed wheel of the wire drawing machine will not groove). During continuous annealing, the tension and air pressure should be paid attention to, and it should not be too large, otherwise the wire will be thinned a lot, resulting in serious wire binding. The adjustment is adjusted on site according to different wire diameters. The corresponding annealing air pressure is different for different copper manufacturers. It is best to find out the empirical data for fixing copper materials on site. The theoretical data is not reliable. Sometimes in continuous annealing manufacturers, annealing and no annealing are required. Workers on site adjust the tension and air pressure during annealing. If they do not increase the pressure in time when annealing is not performed, the tension and air pressure will be too low and there will be problems with wire drawing. Pay special attention to this point.
6 The current control system is becoming more and more advanced. Unlike the previous contactor relay control system, the more advanced things need more professional staff to take care of them. The phenomenon that the operators randomly adjust the frequency converter parameters and annealing plate potentiometers appears on the spot, and they are adjusted. Do not know how to transfer it back, it will cause unnecessary equipment complaints. When no professional electrical personnel are present, it is strictly forbidden for operators to play with the inverter and annealing control board without authorization, and explain clearly to the customer during the installation and commissioning of the equipment.
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