Rheological properties of ground cinnamon

USE

Determination of the flow characteristics of ground cinnamon powder.

TEST EQUIPMENT

Instrument: powder flow tester (PFT)

Tank: 230 cc, 6 inches in diameter (standard volume)

Lid Type: Pallet Lid, 33cc, 6 inch diameter

Wall cover, 2B finish, 6 inches in diameter

Test Type: Flow Function Test

Temperature: Room temperature (70-72 ° F)

Humidity: 48%

METHOD

A Brookfield powder flow tester equipped with Powder Flow Pro software for automated instrument control and data acquisition was used to test ground cinnamon. The cinnamon was collected in the trough and the scraping tool was then used to evenly distribute the powder and form the sample. After recording the sample weight and entering it into the software, a standard flow function test was performed. The time required for the test was 25 minutes.

MEASURED PARAMETERS

Fluidity: easy flow / cohesive

Bulk density: 446 kg / m 3 (filling density) to 589 kg / m 3 (final bulk density)

TO ANALYSE

Hopper shape: Conical

Critical arch dimension: 0.085 m (85 mm; 3.3 in.)

Rat hole diameter: 0.864m (Bin diameter 2m)

RESULTS

Figure 1 shows the flowability of ground cinnamon at different levels of consolidation stress. These results show that cinnamon flows easily at higher consolidation stresses, then becomes more cohesive and difficult to flow at lower consolidation stresses.

Note: Flow function data is indicated by the red line. The other lines are references (or “Standard Flow Indices”), which distinguish the different types of flow behavior, ranging from “non-fluid” to “fluid”.

The axes are the unconfined breaking strength (kPa) with respect to the major principle consolidating stress (kPa).

Figure 1: Graph of the compression ratio function of ground cinnamon

Figure 2: Dimensions of the arch and diameter of the rat hole

Figure 2 shows the dimension of the arch and the diameter of the rathole (based on a standard bin diameter of 2 meters and a bin height of 8 meters). An opening greater than 0.085 m is necessary to prevent the formation of a cohesive arc. An opening of more than 0.864 m is necessary to avoid the formation of a rat hole. These values indicate a material that may have flow problems.

Figure 3: Bulk Density Graph of Ground Cinnamon

Figure 3 shows the bulk density of the material at different levels of consolidation stress. This graph tells us that ground cinnamon has a filling density of about 446 kg / m³ and amounts to about 589 kg / m³ at about 9.6 kPa of consolidation stress. In general, a free flowing powder will show very small changes in bulk density, while a cohesive or low flowing powder will generally show a large increase (30 to 50 %) of the bulk density. This cinnamon shows an increase of 32% bulk density, indicating that this powder may have a flow problem.

The axes are the apparent density (kg / m3) compared to the consolidation stress of the major principle (kPa).

CONCLUSION

Ground cinnamon begins to flow easily when the feed system is full, and then becomes cohesive at lower consolidating stresses as the system empties. Possible problems include the formation of cohesive arcs (when the powder forms a cohesive bridge on the outlet) and rat holes (when the powder only flows from the center, leaving the rest of the static material against the walls). This material flows like many spices do in that it starts off as an easy-flowing material and then gains strength, becoming more cohesive as the system empties. Cinnamon, being a spice, will also be hygroscopic, so high humidity levels will make this material even more difficult to drain.