On the feasibility of vibrationbased degassing of highly viscous liquids

Degassing of liquids and suspensions is a critical process in a variety of industrial applications, including mineral processing, and the mining and metallurgical industries. Effective degassing is essential in operations such as oil and petroleum product processing, metal leaching, machine oil recycling, concrete mix preparation, ceramic slip processing, and maintaining stable performance and high flow in heavy-duty pumping systems. A range of methods are typically employed to address degassing, including settling, vacuum application, increased pressure, ultrasound, cavitation, and centrifugal forces. However, these techniques often prove ineffective for highly viscous liquids or when small gas bubbles are present. In the model liquid used in this study—silicone oil PMS 10,000 cSt, with a kinematic viscosity coefficient of 10–2 m2/s, 10000 times that of water—the ascent rates of air bubbles with diameters of 0.4 and 0.7 mm are only 8.7 and 26.7 μm/s, respectively, making the settling of small bubbles impractical for degassing. Such high viscosity values are common in low-temperature oils, certain melts, and other thick liquid media. This paper demonstrates the potential for degassing highly viscous liquids containing small gas bubbles through resonant vibration, which enhances bubble removal efficiency by generating a standing wave within the gas-liquid medium. The study identifies key parameters and their interrelationships, enabling the implementation of the required operating conditions. Experimental validation shows that the degassing time with vibration is several orders of magnitude shorter compared to traditional settling methods.This research was conducted under the state assignment of the Ministry of Science and Higher Education of the Russian Federation for the Institute for Problems in Mechanical Engineering of RAS (Reg. No. 124040800009-8).