SU1201995A1 - Device for controlling rectifier for supplying electrolyzer - Google Patents

Abstract

The invention makes it possible to increase the efficiency of a rectifier control device (VCC) for powering the electrolysis cell by obtaining a reverse current due to a 2/3 half wave of a sinusoid of one of the voltages equal in duration T: 3 with an increased switching frequency, as well as mym and reverse currents. This effect is achieved due to the fact that a pulse shaper 44 with an output frequency, a six-fold network frequency, two decoder 39, 41, a two-board switch 38 and two amplifiers 35, 36 are entered into the VLV. Moreover, the ratio of the forward and reverse currents i is controlled by matching the number of pulses from the imager 44, (L implemented with the help of a switch 38о 9 Il.

Description

The invention relates to electrical engineering and can be applied to electroplating baths and electrolyzers for electrocoagulant sewage treatment with periodic pulsing with a reverse pulse. The aim of the invention is to increase efficiency. Figure 1 presents the block diagram of the proposed device; 2, the oscillograms of the curves of the formation of a periodic current depending on the operation of the device, respectively, are three phase phases of the automation power supply unit, as well as at the input (FIG. 3) and output (FIG. 4) of the pulse former, the positions of the first group (FIG. 3). ) and the second group (Fig. 6) of the current reversing unit recalculation trigger, after the first and second program block amplifiers (Fig. 7) and forward and reverse current thyristor control systems (Fig. 8); Fig. 9 Oscillograms of the output voltage supplied to the bath or electrolyzer. The device consists of a three-phase transformer; 1, having primary windings 2-4 and secondary windings 5-7 and 8-10, connected in two stars. The midpoints of the stars 5-7 and 8-10 are connected through reactors 11, 12 to the electrode 13 of bath 14, and the remains of the windings 5-7 and 8-10 under are connected to the thyristor anodes 15-2O forming the direct current pulse and the thyristor cathodes 21-26, forming a reverse impulse. Thyristor cathodes 20-15 are connected to thyristor anodes 21-26 and through the measuring device 27 to the second electrode 2 of the bath. Each of the control electrodes of the thyristors 15-20 and 21-26 is connected to the corresponding channels of the unit. 29 control of these thyristors, which contains a block 30 of protection and two separate channels for controlling the thyristors direct 31 and the reverse of 32 current pulses. The direct current and reverse 32 thyristor control channels with 32 current pulses include the outputs of the current reversing unit amplifiers 33 and 34, respectively, to which the outputs of the amplifiers 35 and 36 of the program block 37 are connected. The input of the amplifier 35 is turned on via a dual board 38. As decoder 39, which is connected to the counter 40 of the device for reversing the current of the device, and the input of the amplifier 36 is connected to the output of the decoder 41 of the device for reversing the current of the device. Additional outputs of the decoder 39 through the switch 38, as well as the output of the decoder 41 are connected respectively to the inputs of the RS-flip-flop 42 of the reverse unit. The inputs of the counters 40 and 43 are connected to the output of the pulse generator 44 (software block 37), which is connected via capacitor 45 to the cathodes of the three-phase rectifier 46 of the device's thyristor control automation power supply unit. The device works as follows. Let us consider an example when it is required using the proposed program block to obtain four forward pulse and one T reverse current pulse on the bath electrodes using the thyristor control system and the reverse unit of the rectifying unit. In this case, for a certain alternation of the number of forward and reverse pulses, counters 40, 43 of forward and reverse pulses of the current reversing unit are used in conjunction with decoders and amplifiers of the program block. The rectifier 46 of the automatic power supply unit rectifies the rectified current (Fig. 2) having a variable component (fig. 3) of the six-phase current, from which short pulses are formed with the help of capacitor 45 and pulse shaper 44 (fig. 4) to control the counters 40 and 43. Counters 40 and 43 are alternately braked by reset circuits, which matured controlled by RS-flip-flop 42 (Figure 7). At the instant of arrival of the first pulse, the EBtrigger 42 is in a position where O (BAN) is supplied to the input of control channel 32 via amplifier 34 to this channel. Then, the control channel 31 has the ability to generate control pulses for the opening of thyristors of direct current. At this moment, the count of the number of control pulses of the counter 40 begins, which through the decoder 39, the switch 38, the amplifier 35

fig.b) prohibits control channel 31 to eliminate the fifth control pulse of opening the direct current thyristors. With this fifth pulse counter 40 through a decoder 39, switch 38 switches RS-flip-flop 42, which through amplifier 33 delivers O (banned) input of control channel 31 and CHiMaO O (BAN) from control channel 32, which leads to the opening of the reverse current thyristor (Fig. 7) on the sixth pulse.

Simultaneously with the arrival of the fifth pulse, the counter 40 along the reset circuit from the amplifier 33 is reset.

With the arrival of the sixth pulse from the pulse generator 44, the counter 43 starts counting, with the arrival of the seventh pulse through the decoder 41, the nipple 36 supplies O (RETAIL) to control channel 32 to exclude the seventh reverse current thyristor pulse (Fig. 8). At this time, the forward current thyristors also do not receive opening control pulses. With the arrival of the next (eighth) pulse from the pulse former 44, the counter 43 is fed through the decoder 41 to the initial state of the RS flip-flop switch 42 and the counter 43 is reset. With the eighth pulse from the pulse former 44, the cycle of the device repeats. The shape of the rectified current is shown in FIG. 9,

Adjusting the ratios of forward and reverse currents is carried out by selecting the number of pulses applied to the triggers of the first account, i.e., N 2, where n 1.11, Accordingly, this ratio can be selected from 2 to 2048. At the same time, the second counter forming the prohibition of one reverse current pulse after the start of switching on the reverse current thyristors remains unchanged. This creates the possibility of flexible control of the ratio of the forward and reverse current pulses within the limits (2 ,,, 1024): 1.

The application of the proposed device allows: to obtain a reverse current due to 2/3 of the half-wave of a sinus of one of the voltages equal in duration T / 3 (120) with a higher switching frequency, which favorably affects the quality of applied cathode coatings and improves technological conditions the operation of electrolyzers during electrocoagulation wastewater treatment by reducing the passivation and slime of the electrodes; eliminate the pause between forward and reverse currents, which contributes to an increase in

useful effect of the device and has a positive effect on the course of electrode processes that affect the adhesion of coatings to the substrate and the formation of their structure by eliminating

neither the surface passivation during the pause period, as well as preventing the adsorption of surfactants during such a pause during the anodic dissolution of metals in the processes of electrochemical wastewater treatment; to expand the range of regulation by periodic current depending on the set technological tasks during the deposition of electroplating and

electrochemical wastewater treatment.

Claims (1)

Invention Formula A device for controlling a rectifier for powering an electrolytic cell containing the first and second control channels, the outputs of which are designed to connect direct and reverse currents to the thyristors, respectively, two counters, an RC-trigger and two main amplifiers, the purpose of increasing efficiency, it is equipped with formu-. pulses with an output frequency, a six-fold network frequency, two decryptors, the first of which contains the first group of outputs connecting the Aoparno neighboring states and the second group of outputs, a dual board switch, two additional amplifiers, the input of the pulse shaper is intended for connection to the mains, and the output connected to the counting inputs of the first and second counters, the outputs of which are connected to the inputs of the respective decoders, and the installation inputs to the output .- ::: RS flip-flop and the inputs of the second and first additional amplifiers, respectively, the first output of the first decoder through the first board of the dual board switch and the first main amplifier is connected to the output of the first additional amplifier and the input of the first control channel, the second output of the first decoder and the first output of the second are connected to the RS trigger inputs, the second output second decoder via the second main amplifier connected to the output of the second amplifier and the input dopolnitelngo second channel uprvleni. L L L / L L L L / L / L L A V / 1 1 1 1 1 V V 1 1 t t "I t I) f f 1) 1, Fri / in 45rYYYYYYYYYYYYYYY. / ". ,, linnininiim  t g 3 1 s 6 zynlgakek 7L UTL  . Rigg G / U1 and UL a cSpoc