Application Cases

Experiment Name: Application of Power Amplifiers in the Study of Sludge Dewatering Characteristics and Parameter Optimization under Pulsed Waveforms

Experiment Objective:
This paper investigates the influencing factors of sludge electro-dewatering, such as pulsed signal waveform, frequency, and duty cycle, to study the effects of pulse parameters on sludge electro-dewatering results.

Experimental Equipment:
Signal generator, ATA-304 power amplifier, oscilloscope, connecting wires, metal piston, insulating sleeve, etc.

Experimental Content:
Study on the effect of pulsed waveforms on sludge electro-dewatering performance. Under a pulsed electric field, the waveform, frequency, and duty cycle of the pulse signal are varied to explore the influence of pulse parameter changes on sludge dewatering characteristics. By measuring parameters such as sludge temperature variation, current variation, cathode-side filtrate mass change during the electro-dewatering process, as well as post-reaction sludge pH, filtrate pH, filtrate COD, sludge conductivity, and sludge thickness change, the characteristic changes after sludge electro-dewatering under pulsed waveforms are analyzed, and efficient and suitable pulse electro-dewatering parameters are selected.

Experimental Procedure:
First, place the polypropylene filter cloth and stainless steel mesh on the lower metal filter plate, which is positioned on the base. Then, fit the insulating sleeve and metal sleeve respectively, and secure the sleeve and base with screws. Next, weigh 37.5 g of sludge that has been allowed to settle to room temperature using an electronic balance, pour it into the insulating sleeve, tamp it flat, insert the metal piston, and connect the thermocouple and wires from the piston. Then, connect the anode of the device to the positive terminal of the amplifier and the cathode to the negative terminal of the power amplifier, and connect the current probe and voltage terminals of the oscilloscope into the circuit. At the same time, place a beaker on the balance to collect the real-time mass change of the cathode-side filtrate during the experiment. Finally, turn on the signal generator and adjust it to the set value, turn on the power amplifier, and adjust the amplification factor of the electrical signal in the circuit to the set value according to the data displayed on the oscilloscope. The experiment lasts for 45 minutes, during which the current value, temperature value, and cathode filtrate mass value are recorded every minute. After 45 minutes, first turn off the power supply of the power amplifier, then release the pressure of the jack, and collect the cathode-side filtrate and sludge cake for further testing and analysis.

Experimental Results:
The scanning electron microscopy results of the internal structure of the sludge after dewatering fully demonstrate that the key to deep sludge dewatering lies in disrupting the floc structure inside the sludge, releasing the difficult-to-remove adsorbed water and bound water. Once the sludge flocs are broken, the dewatering process can be significantly advanced, thereby further reducing the moisture content of the sludge. The destructive ability of sine waves on sludge flocs is stronger than that of square waves.

Figure: ATA-304C Power Amplifier Specifications and Parameters