Gonell elutriator

Weilbacher confirmed that the parabolic laminar velocity distribution forms near the upper end of the Gonell elutriator. He noted that the arrangement at the top of the tube for the removal of fineparticles fractionated in the chamber moved them through the boundary region of low velocities at the side of the tube, thus causing resedimentation into the boundary region and down the elutriation column thus prolonging the separation process. 

Gravitational Methods GONELL AIR ELUTRIATOR. This is the prototype of all analytical separators with laminar air flow. It consists of a cylindrical brass tube (or a series of tubes) with a conical base. An air inlet is provided in this base on the axis of the tube. The sample of powder is placed in the inlet cone, and air is blown thru the largest tube until separation is deemed complete, or for specified periods of time. The residue is removed, weighed, and transferred to a smaller diameter tube, and the test is repeated. The tube should have polished internal surfaces and should be periodically tapped or vibrated to disturb settled powder... 

Fig 11 Effect of elutriation time on the amount of residue in the glass attachment of the Gonell Separator for different tubes and air mounts... 

Fig 12 Relation of the granularity characteristic curves to the elutriation times at 5.5 hours and at 1.5 hours in the Gonell Separator... 

Gonell Air Elntriator. A down-blast type of elutriator (q.v.) designed by H. W. Gonell (Zeit. Ver. Deutsch. Ing., 72, 945, 1928) it has found considerable use in Europe for assessing the fineness of Portland cement. 

This part covers air elutriation methods, such as the Gonell, the Roller (modified ASTM), and the miniature elutriation methods. As these are rarely, if ever, used for particle size distribution determination nowadays, it is likely that this Standard will be withdrawn. 

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