SU1204650A1 - Device for instantaneous connection and disconnection of current supply in electroplating cell - Google Patents

Description

The invention relates to devices for the electrochemical treatment of materials and can be used in optimizing electrochemical processes, in particular for determining and controlling the modes of activation and passivation of the surface of electrodes under conditions of their polarization with a periodic current with a reverse pulse during electroplating, as well as in electroplating. wastewater treatment.

The purpose of the invention is to increase the efficiency of the process of optimization of electrochemical modes by switching on and releasing a periodic current and with a reverse pulse at a given time from the beginning of the current period. -.

The drawing shows a block diagram of the device.

The device contains a power supply unit 1, into one of the windings of the power transformer of which a shaper 2 pulse generator is connected, having an output to a single vibrator 3, the circuit of which has a regulator 4 of pulse duration and the output of a single vibrator connected to the bases of transistor switch 5 and transistor key 6, connected in series to the one-shot through the inverter 7, key collectors are interconnected and connected to the output of the power meter 8, and the emitters of the keys are also connected between themselves connected to the auxiliary telnomu electrode cell 2 i 9, the main electrode 13 which is connected to a second output vtr DC converter 8 and electrolytic key 10 with reference electrode. The current forms and the moments of its switching on and off are fixed by an oscilloscope 1 connected to the outputs of the pulse former 2, the emitters of the keys 5 and 6, and the reference electrode of the electrolytic key 10, the electrochemical cell 9 has an auxiliary electrode 12 and the main electrode 3 to which the capillary is led electrolytic key 14, which forms a closed electrical circuit with a comparison electrode 10,

The device works as follows.

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Pulse generator 2 receives a sinusoidal voltage from one of the windings of the power transformer of power supply unit 1 and converts it into sharp-pointed pulses with a duration of 3-5 ms with a steep leading edge needed to start the single vibrator 3 and simultaneously sweep the oscilloscope 11 .

A single vibrator 3 produces a single pulse of negative polarity of a rectangular shape, the duration of which can be adjusted by means of the controller 4 from 5 to 50 ms. The leading edge of the one-shot 3 pulse (at the start of the oscilloscope sweep) includes the transistor switches of forward 5 and reverse 6 current pulses, and through them the auxiliary electrode 12 of cell 9 connects to the output of rectifier 8, to match the output of the single-vibration 3 to the output of transistor switch 6, requiring a positive polarity signal, an inverter 7 is applied,

The back edge of the pulse of the one-shot 3 triggers the transistor switches of the forward 5 and reverse 6 pulses of current, and the current is interrupted at the auxiliary electrode 12 of the cell 9. The surface potential potential of the main electrode 13 is removed using an electrolytic key with a comparison electrode 10.

When working with the proposed synchronization device, the sweep of the oscilloscope 11 must be included in the operation mode of the external synchronization of the waiting sweep.

Thus, the current breaking moment is always; or it can be precisely selected depending on the pulse width of the one-shot using the controller 4. The device allows multiple reproduction of the current pulse and its discontinuity at a given time with the start of the oscilloscope sweep in exactly the selected part of the current period .

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This makes it possible to switch on and disconnect the auxiliary electrode current circuit at any given moment from the beginning of the period of the selected current waveform, as well as repeatedly reproduced. conduct a change in the current and potential of the electrode surface on a two-beam

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an oscilloscope of type C1-16 or anapot types.

Instant switching on and discharging current into a controlled exactly specified and repeatedly recorded on the oscilloscope screen the time instant of a change in the current curve sweep. the period of the electrochemical process leads to a decrease in the surface potential of the electrode, which changes with a delay in time, gradually reaching its stationary value. The time of establishment of a stationary potential, recorded on the oscilloscope screen, characterizes the state of the active surface during the electrolysis period, as well as the speed of passivation processes on the surface of the electrodes.

When using the device for instantaneous switching on of the current at the moment of starting the sweep, a skip occurs. A potential block, the value of which is related to the state of the active surface of the electrode. The time of the potential drop to a steady-state value at a given current density characterizes passivation processes during electrolysis.

Periodic discharge and switching on the current through different predetermined intervals of time allows one to quantify the state of the active electrode surface during the electrolysis process and to optimize the conditions of the electrochemical processes.

Thus, the criterion for the optimality of the modes and conditions of electrolysis is the maximum degree of activity of the surface of the electrodes, which is determined by the curves of changes in potential when the polarizer is turned on and off. In this case, the degree of surface activity can be controlled by varying the magnitude or duration of the reverse current pulse.

The efficiency of the process of optimizing the electrochemical regimes, in contrast to the known, where the moment of switching on and breaking the polarizing current and the corresponding change in the electrode potential jump, is random in this solution, this solution provides accurate reproducibility of the results from 04650

current and potential measurements over time.

 . The establishment of optimal electrolysis modes and the regulation of reverse current pulse 5 allows the electrochemical processes to be carried out in an activation mode, which contributes to the intensification of these processes by increasing the working density of the current, improving the quality of electroplating coatings, increasing the current yield of the metal, reducing energy costs and metal electrodes

Electrochemical (electro-15) wastewater treatment.

Positive effect due to an increase in the efficiency of the electrochemical optimization process; modes with respect to the prototype, 20. is achieved by the following,

In contrast to the well-known where the discharge of an electrical circuit in the time-period of the current is random, this device ensures the start

25 sweep the oscilloscope and the timing of the current gap depending on the objectives of the study,

This device is contactless, electronic, fast-acting, with an unlimited switching time, which eliminates a number of negative effects inherent in devices with an electromagnetic relay according to a known device, such as rattling of contacts, the arc between them

 and a delay in the time of contacting, their burning, etc. This device can be used to instantly break the current circuit, or turn it on after various periods of time, ensuring accurate repetition of a given mode, and it can be used for use as a periodic multiphase current with

 reverse pulse and direct current.

The economic effect of using this device while optimizing the modes of electrochemical processes using a periodic current with a reverse pulse is achieved due to the improvement of the quality of electroplated coatings and their adhesion to the main due to the definition

55, and the elimination of the causes that lead to the passivation of the surface of the electrodes; optimization of conditions for increasing current output and intensifying pro30

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a cathode electroplating coating process; ensuring the conditions of anodic dissolution of metals in the activation mode during electrochemical (electrocoagulation) treatment of wastewater by preventing sludge and increasing the utilization of metal

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electrodes; reduction of nonproductive power consumption due to LOW voltage on the electrodes. in terms of preventing passivation of their surface.

The economic effect from the introduction of this device is 6.2 thousand rubles.

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Claims (1)

DEVICE FOR INSTANT. CURRENT SWITCHES AND DISCONNECTIONS IN THE ELECTROLYTIC CELL, including the main and auxiliary electrodes, a power supply unit with a power transformer, a sweep start relay; an oscilloscope with a thyratron for breaking current in the cell, a start relay contact and a power rectifier, characterized in that, with In order to increase the efficiency of the process of optimization of electrochemical modes by switching on and breaking a periodic current with a reverse pulse at a given point in time from the beginning of the current period, it is equipped with transistor switches, invert ohm shaper needle pulses, is connected to one of the windings of the power transformer, One-Shot timer with a pulse width controller, which input is connected to the monostable output of the ostrokonech- _β pulses and the input trigger circuit S oscilloscope, and the output of the monostable is connected both to the base of a transistor keys and to the inverter, the output of which is connected to the base of another transistor key, the emitters of the keys are interconnected and connected to the auxiliary electrode of the cell, and key collectors are interconnected and connected to the output of the power rectifier. S U 1204650