Effect of carbon based nanoadditives on external gear pump performance

External gear pump;Nanoadditives;Carbon Nanotube (CNT);Carbon Nanofibers (CNF)

Martorana, Philip J. ; Loth ; Eric ; Bayer ; Ilker

关键词: External gear pump;    Nanoadditives;    Carbon Nanotube (CNT);    Carbon Nanofibers (CNF);   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/29698/Martorana_Philip.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

AbstractEffect of fine graphite flake, carbon nanotube, and carbon nanofiber additives on theefficiency of an external gear pump driving an ethanol-based closed hydraulic loop wasinvestigated experimentally. A number of graphite, carbon nanotube (CNT) and carbonnanofiber (CNF) dispersions in ethanol were prepared with concentrations ranging from 194-1500 ppm. The fluids were investigated in an external gear pump with a maximum operatingpressure of 100 psi. Pump inlet pressure, volumetric flow rate, and electric power consumptiondata were recorded over a range of pump discharge pressures. The power consumed by themotor at a given differential pump pressure was found to remain approximately constant for alladditive concentrations. It was found that increases in both volumetric flow rate and overallpump efficiency were observed when pure ethanol was replaced by the colloidal suspensions.This was attributed to a roller bearing effect caused by the alignment and self-lubrication of thecolloidal additives when confined to micro-scale clearances between the gear surfaces. It wasfound that that pump performance was also a function on the CNT aspect ratio and could veryfrom pump to pump, or even after a pump was disassembled and reassembled. This indicatesthat the clearance geometry between the gears and between the housing may play a criticalrole.To examine any potential structural changes in the additives, environmental scanningelectron microscope (ESEM) images of the additives were obtained before and after extendedrun periods within the pump. The results indicate that graphite and CNTs retained significantresilience, i.e. no breakage and deformation was observed. However, the very long aspect ratioCNFs appear to have undergone some scission. To examine any issues with filterability,iiigraphite and CNT suspensions were run through two filters of different size and compositionand the filters where then qualitatively examined using ESEM images. The results indicate thata considerable amount of the additives were filtered from the suspension. This indicates thatfilterability is an issue that needs to be addressed if these suspensions were to be used inindustrial applications.