On a New Type Apparatus for Gathering Saltant Soil Particles

Abstract

Many papers are published about the aerodynamical saltatorial mechanism of soil and about the effectivity of several protection measures against winderosion. Recently they are interested in the physical and chemical properties and in the vertical distribution of saltant soil particles. For this purpose, several apparatus are applied to gather saltant soil particles (Fig. 1, No. 1-8). The small sized particles with the trifling inertia energy will either run out because of the accelerated airdrawing, or not enter at all, for the streamline is strongly disturbed already at the entrance of the apparatus (Fig. 1, No. 1-8).
In order to catch the small sized soil particles besides great soil particles, the authors have devised a new model (Fig. 2), at whose exit the speed of the airstream is diminished until 1/36 of the initial speed. Thereafter the floating particles need about 1.1 seconds to pass through the apparatus. In this 1.1 seconds a particle (specific gravity 2.0) with the radius of 14 micron falls 5.5cm (calculated by McCubbin's formula). Moreover the new type apparatus has no disturbance at its entrance (Fig. 1, No. 9 and 10). The entrance of the apparatus is built so low for the great soil particles, that they are affected directly to creep and fall into the gathercase.
The comparative examination of several apparatus on their gathering ability of saltant particles shows that the new type possesses substancially better gathering ability especially of the smaller particles (Table 2).
As the apparatus for practical use we have built the black painted apparatus made of iron plates with a vane. The apparatus is fastened up on the iron rod with a ball bearing and may be therewith turned (Fig. 1, No. 11 and 12). In order to research the vertical distribution of saltant particles small changes are undertaken on the size of the entrance and the exit; the entrance section 1cm×5cm and the exit section 7cm×29cm.