Measurement of equivalent radius, bulk density and solid density of granular materials
INTRODUCTION
Granular material is a group of distinct macroscopic particles, composed of grains or particles of solids with interstitial spaces, which are the spaces between the particles. Having spaces between the particles means that there are rooms left for the filling of air or liquid. This concept is applied as to use the filling of liquid to determine the volume of the particles later on. The objective of this experiment is to measure the equivalent radius, bulk density and solid density of granular materials, which is in this experiment, the red beans and the soy beans. The solid density of granular materials is defined as ρs, which is the density of the material in the grains, to determine whether the material will float or sink in water. As for the bulk density, ρb, this is the important property for storage and transportation as whole. Density is defined as the mass divided by volume occupied by the particles. Porosity, on the other hand, is the volume fraction trapped between the particles.
MATERIALS
1. Red beans
2. Soy beans
APPARATUS
1. 100 ml measuring cylinder
2. 50 ml measuring cylinder
3. Analytical balance
4. Cooking oil
RESULTS
Red beans
Soy beans
Weight of 400 beans, M (kg)
0.07175
0.07172
Volume of 400 beans + void spaces, V (ml)
90.00
102.00
Initial reading of cylinder, v1 (ml)
50.0
50.0
Final reading of cylinder, v2 (ml)
17.0
6.0
Volume of void space, v (ml)
33.0
44.0
Volume of 400 beans (m3)
5.7 × 10-5
5.8 × 10-5
Equivalent radius, r (mm)
3.4 × 10-8
3.46 × 10-8
Solid density, ρs (kg/m3)
1258.77
1236.55
Bulk density, ρb (kg/m3)
797.22
703.14
Porosity, ɛ
0.367
0.431
Table 2.1: Data of equivalent radius, solid density, bulk density and porosity of granular materials.
DISCUSSION The objective of this experiment is to measure the equivalent radius, bulk density and solid