Vol. 5 No. 08 (2025)

The article presents the results of a study conducted to determine the effect of the clearance between the cutting edges of the saw teeth of a rasp drum and the working edge of a grate with a diameter of 15 mm on the cleaning process. According to the research findings, the highest cleaning efficiency was observed when the slats had a diameter of 15 mm, the spacing between them was 30 mm, and the distance from the tips of the saw drum teeth to the edge of the slatted grid was 18 mm. As the distance between the saw drum tooth tips and the edge of the slatted grid increased from 15 mm to 18 mm, the cleaning efficiency for first-grade industrial cotton increased from 86. 4% to 90. 5%. However, when the gap increased to 19 mm and 20 mm, the cleaning efficiency decreased to 88. 3%. For third-grade industrial cotton, cleaning efficiency rose from 87. 6% to 92. 9% as the distance increased up to 18 mm, then dropped to 90. 6% at 19 mm and 20 mm. Additionally, it was determined that as the distance increased, the amount of free fibres and the contamination of cotton by impurities decreased.

Gas sensing is critical for environmental monitoring, industrial safety, and healthcare diagnostics, particularly for detecting hazardous or significant gases like volatile organic compounds (VOCs), ammonia, and formaldehyde [1, 2, 3, 4, 8, 10]. Traditional gas sensors often require external power sources, which can limit their portability and deployment in remote or harsh environments. Self-powered gas sensors, which harvest energy from their surroundings, offer a promising solution to this limitation. Triboelectric nanogenerators (TENGs), devices that convert mechanical energy into electrical energy through the coupling of triboelectrification and electrostatic induction, have emerged as effective power sources and active sensing components for self-powered gas detection systems [20, 24, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40]. This review provides a comparative analysis of the sensing mechanisms employed in TENG-based self-powered gas sensors. It examines how the interaction between target gases and the TENG's materials, or integrated sensing layers, leads to detectable changes in the TENG's electrical output. Key mechanisms discussed include changes in triboelectric properties, modulation of integrated resistive or capacitive sensing layers by the TENG's output, and gas ionization effects. Challenges and future perspectives for the development of highly sensitive, selective, and stable self-powered gas sensors based on TENGs are also addressed.