The working principle block diagram of the loss-wave protection circuit is mainly composed of input limiting, shaping, pulse identification, zero-voltage blocking, voltage detection, execution circuit and test circuit. Its input is connected to the DC output of the rectifier. If the output of the rectifier has a filter, it should be connected before the filter. The output waveform period of the three-phase bridge rectifier half-controlled rectification has three peak waves, as shown in (a), after shaping (b). Shaping circuit: The waveform after the front clipping is again formed by a Schmitt trigger to form a rectangular wave with a smaller amplitude.
Pulse discriminating circuit: The shaped rectangular wave is differentiated into a sharp pulse, and then pulsed by the lost pulse discriminator. The pulse discriminator determines whether to issue a pulse to control the conduction of the thyristor according to the oscillation period of the relaxation oscillator (that is, the control angle), and finally drives the relay to perform an action to achieve the purpose of loss protection. The output pulses when the TRIAC is turned on are as follows (e), (f). Zero-voltage lockout circuit: For a voltage-controlled controllable silicon rectifier starting from zero voltage, the rectifier does not output a waveform at zero voltage, which is equivalent to losing all peaks. If no measures are taken, the loss-wave protection will act. To this end, a zero-voltage lockout circuit is added to the circuit to make the circuit not work at zero voltage. Only when the output voltage of the rectifier rises to a certain extent, the protection circuit is turned into a normal working state. (Test circuit: After the test button is pressed, the single-phase AC is added to the input terminal of the circuit after half-wave rectification. Since the single-phase half-wave rectifier has only one peak per cycle, three-phase half-control for three peaks per cycle occurs. The rectifier circuit is equivalent to the loss of wave, and the protection circuit should be operated. Experiments are carried out according to this principle. This circuit component is suitable for the three-phase half-bridge rectifier circuit with output voltage of 01000V. When used for other forms of rectifier circuit, some resistors need to be changed. , capacitance values ​​and other related parameters.
Recycling chemical water system pre-treatment of backwash water, etc. Re-ashing slag chemical pretreatment water system valveless filter, clear water tank, activated carbon filter and other equipment need to be washed with water, these backwash water can be recovered about 1000t / d every day, And its PH value is neutral, can be used directly as ash slag water. Boiler continuous discharge and fixed drainage ash slag boiler continuous sewage discharge and regular sewage discharge PH value of about 10, water volume 12t / h, after cooling, through the sump from the pipe ditch to the ash pool, for rushing Ash. Recycling various cooling water, shaft seal water, etc. for shaft sealing water, air conditioning cooling water, hydrogen production station cooling water, and oil treatment system waste water for various slag ash, about 400t per day, used for ashing Slag.
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