Affiliation: School of Mechanical Engineering, Qingdao Technological University, 266033 Qingdao, P.R. China.
A large number of patents have recently been devoted to the development of minimum quantity lubrication (MQL) grinding techniques that can significantly improve both grinding fluid alternatives in terms of environmental consciousness, energy saving, cost effectiveness, and sustainability. Among these patents, one is for a supply system for MQL grinding that turns the lubricant into pulse drops with fixed pressure, constant pulse frequency, and the same drop diameter. The drops are produced and injected into the grinding zone in the form of jet flow under high-pressure gas and air seal. With the growing demands of our environment, MQL has become widely used in the grinding and cutting machining processes. Based on the dangers of suspended air microparticles from machining to health and the environment, the sources, classification, and characteristics of suspended air microparticles were analyzed in this research. Taking account the features of microparticles, we explored the dangers posed by suspended microparticles to health and identified the common diseases attributed to these microparticles. With the use of the machining process, we analyzed the formation mechanism of suspended air microparticles and conducted research on the distribution characteristics of suspended air microparticles formed from the atomizing nozzle during MQL grinding. The relationship between jet parameters and microparticle size of sprays was explored. The results showed that atomized microparticle size has a linear relationship with nozzle caliber and gas-liquid flow ratio. Atomized microparticle size is directly proportional to the nozzle caliber but inversely proportional to gas-liquid flow ratio. We also analyzed the distribution rules of spray droplets and determined the amount of spray microparticles and volume distribution function.