Ore properties and shape of the mine (2)
C material fall angle Ñ„ and stacking angle Ï Where λ——— Rankine constant (or effective limit stress ratio, lateral pressure coefficient); In order to simplify the calculation, the concept of the collapse angle Ñ„ (Fig. 7) is proposed, and its value varies slightly with the height of the column. If it is considered within 2 meters above the discharge port, the tangent symbol in the formula (2) The angled angle is the fall angle, ie: In actual production, since the material at the bottom of the mine bin sometimes has a long time of compression and firmness, especially when it contains moist muddy powder materials, the change of Ñ„ is more significant. Therefore, the production conditions are simulated in the determination of the delta value. [next] E Flow factor Æ’ Æ’ Advertising Cnc Router,High Quality Advertising Cnc Router,Advertising Cnc Router Details, CN Shandong U-May CNC Technology Co., Ltd. , https://www.sesamecnc.com
a Rankine (a Rankine) constant 
P h ——— horizontal pressure;
P υ ———vertical pressure;
δ———The effective internal friction angle of the material, (°).
b material fall angle
c Stacking angle of material The stacking angle Ï of the material (Fig. 7) is the angle of repose of the material under dynamic conditions (segregation rolling of coarse material), which is smaller than the static angle of repose of the material.
D The coefficient of friction μ of the wall and the friction angle ф′
The coefficient of friction of the material on the wall:
μ=tgф' (4)
Ñ„' is the friction angle between the material and the wall, which can also be measured by a shear meter. As shown in Fig. 4, only the base portion is replaced with a wall material and is a flat plate.
The relationship between the friction angle ф' of the material to the wall, the half angle θh of the bucket wall (the angle with the vertical line) and the effective internal friction angle δ of the material is shown, for example, in FIG.
Jennick defines the flow factor ƒ ƒ is the ratio of the compaction stress σ 1 to the stress σ y acting on the blockage, ie:
ƒ ƒ =σ 1 /σ y (5)[next]
The smaller the ƒ ƒ , the better the fluidity of the material in the mine bin. The critical flow factor of the material arching or knotting in the silo of the flat bottom bin or the bucket half angle θ h is shown in Figure 9; the critical flow factor of the material in the silo is shown in Figure 10.