Development and Performance Analysis of a Novel Triple-Anode Plasma Torch with Annular Powder Feeding for High-Efficiency Powder Processing

Direct current (DC) plasma torches play a pivotal role in the field of material processing, with their performance largely determined by the characteristics of the plasma jet. However, the cascade DC plasma torch produces a plasma jet that has a small high-temperature region and a high velocity, which limits their powder processing rate. This paper designs a novel triple-anode plasma torch (TAPT) equipped with annular powder feeding to address these challenges. Comprehensive investigation into the plasma jet characteristics of the TAPT was carried out through a combination of experimental measurements and numerical simulations. Results show that the TAPT produces an optimal plasma jet for powder processing, marked by a large high-temperature region, low velocity, and high uniformity. The plasma jet’s peak temperature reaches over 20,000 K, with a 4,000 K region of 160 mm in length and 33 mm in diameter, and minimal regions exceeding a velocity of 80 m/s. The annular powder feeding of the TAPT guarantees a stable plasma jet for effective material processing, with the arc voltage exhibiting a small standard deviation of just 1.08 V. Furthermore, the TAPT’s effectiveness in powder processing was exemplified by spheroidization trials involving aluminum oxide powder, which yielded a practical specific energy requirement of approximately 4.35 kWh/kg. Overall, the TAPT shows considerable potential in the field of powder processing, specifically in raising the efficiency of powder spheroidization processes.