User:Pedrazjo

Annealing by Short circuit

Brief history of the Annealing of the Copper wire.

Time back, the task of making copper wire of smooth weather (C.R.U ≈ 20 Kg/mm ²), used methods that gave result, but the manufacturers know that they were expensive,necessary,and took long time, was the only form to anneal the copper wire and to give an appropriate electrical and mechanical characteristics for use on Cables types General Use, Energy, Telephony lines.

Nowadays with the development of science in the branch of electronics they makes this possible by using of semiconductors like Thyristors, PLCs, Integrated circuits, that enormously facilitate the task in Power control.

These advances in electronic the modern have done possible to design sophisticated and efficient machines, but in diverse branches of the industry, and thus to obtain excellent results within a great frame of trustworthiness giving rise to “the Annealing of the copper wire by using a Controlled Short circuit”

Contents [hide] 1 Using the Old Method 2 Dynamic Annealing of the copper wire by a Controlled Short circuit 3 Uses and characteristics of the Annealing by Short circuit 4 Description of the process 5 Is also seen 5.1 References

[edit] Using the Old Method Annealed.

Troublesome process in which it was introduced to a furnace of regulated temperatures, certain amount of copper sinking in iron spools and leaving it to fixed beforehand conditions of temperature and time to obtain the mechanical characteristic, passing it of a C.R.U ≈ 40 Kg/mm ² to C.R.U ≈ 20 Kg/mm ² annealed, that is to say soften it and soon to process it in a later stage in stranded machines and to obtain therefore a smooth copper thread meeting besides taking step to the next process that is to form prudent and/or soft copper thread thorons, with which cables of any dimension and required typical will be able to be made.

But this method already has been surpassed with the continuous annealing, that is to say annealing in the same machine without needing having to stop the sinking process and to accumulate load for the annealing furnace, with which time is saved, personnel, space, nitrogen; this gas is used stops to avoid the oxidation of the thread and is necessary to break the initial emptiness to which the copper load was put.

[edit] Dynamic Annealing of the copper wire by a Controlled Short circuit The process consists to put in the way of exit of copper sinking pulleys that were to Electrical Potential called step pulleys, this potential of pulleys with a section of very low resistance of the copper thread happening through them create a current of Short circuit and this as well produces the Joule effect, that is the one in charge to anneal the copper when giving temperature and to change to its electromechanical properties.

[edit] Uses and characteristics of the Annealing by Short circuit One is used to soften copper and to give electrical use him in the manufacture of electrical coductors. An increase of the conductivity in the case of copper is obtained. The annealed temperature of slightly over the 400 ºC. Quenching. Increase in the speed of production. Trustworthiness in the process. Significant reduction of the idlings in production. Clean process and probability of errors to the minimum.

[edit] Description of the process

Trefiladora de CobreSinking copper machine it will be possible to be seen clearly that when having a section of copper between pulley and pulley with a potential difference this will draw by the Law of Ohm a current that following the ohmic resistance of the copper section and the applied tension it will force to that a current circulates that can reach great values and is exactly the dynamics of I balance thermal, the one that is going to regulate the amount of heat which this a can absorb the copper section overheating and thus to change its conditions of copper it last to smooth or semi-soft copper, all these thermal conditions are come off the laws of thermal balance that for this by the Joule Effect; Final equation in steady state for the annealing of copper.

T°C = ((KV ²)/(rpm))+t (a) As additional data we have it temperature of expert of copper is approximately 400°C. Annealed T = Temperature of in °C.

rpm = Angular velocity in revolutions per minute. t (a) = Room temperature in °C. V = Tension applied in Volts. Where K is a constant that depends on the diameter of the passage pulleys in which this applied the electrical Potential, resistivity of copper, of the mechanical equivalent of the heat.

1 Calorie = 4,186 Joule.

We can say, as we know the temperature the annealing of copper ≈ 400°C and t (a) the room temperature 20°C, we will have a Parabola of the following form:

KV² = 380.(rpm), to that we will call Parabola of Electrical Load. Final equation that bind the Annealing Voltage of wire and the angular velocity of the pulleys of annealed and which if we introduce the diameter of the same in the equation we will have electrical stress ratio of and linear rate of copper when happening through the pulleys and that are exactly this linear rate the speed of sinking is the speed of the process. This equation can be used to consider the annealing of any other metal.

Also we can induce by simple inspection of the Parabola, that the annealing of a copper gauge will only depend on the relation between the two variables Tension versus Speed, then to manage to reduce times of production will be necessary to give to the line the maxima speed, at maximum speed it will appear according to the Parabola of electrical Load a tension that corresponds to him and that fulfills the equation.

This important equation binds the temperature of of the metal with the speed in rpm of the pulleys and the applied electrical voltage. which can be seen clearly that at greater speed, major applied tension and staying the resistance ohmic of the then constant copper section the current will be greater, is logical and in addition it is come off the simple equation of the ohmic resistance then we will say: then will say : bigger Voltage bigger current greater speed across the line.

Note: In order to know the law dependency between the speed variables and annealed tension of in transient state, it will be necessary to apply to Differential equations to the function of steady state, combining with the conditions of state in starting and shutdown of the Sinking machine,the result is an equation of exponential form.

[edit] Is also seen Annealed Sinking Short circuit

[edit] References Autor = Jorge Luis Pedraz Títle = Thesis of Degree, Cable Manufacture and Tests of General Use and Energy. Year = 1994 Pulication = UNI, Files, Peru.

Autor = Jorge Luis Pedraz Títle Dynamic annealing of the Copper wire by using a Controlled Short circuit. Year = 1999 Publication = Peru: Lima , CONIMERA 1999, INTERCON 99,

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