POWDER FLOW
Title of experiment: powder flow
Date of experiment: 19th September 2013
Objective: to study the powder flow ability using different size of hoppers
Introduction:
Powder flow ability is the ability of a powder to flow in a desired manner in a specific piece of equipment. Flow of powders can be free-flowing and non-flowing or cohesive. Manufacturing of tablets, capsules, filling of powder in container involves several powder handling steps, including blending, transfer, storage, and feeding to a press or a dosator. The inability to achieve reliable powder flow during these steps can have a significant adverse effect on the manufacture and release of a product to market.
Material and apparatus:
various size of sand, various size of hopper, weighing boat, spatula, newspaper, stopwatch, analytical balance
Procedure:
1) Five hopper that have different size are chosen
2) Five various size and properties of sand are chosen and weighed using analytical balance
3) The hole of hopper is closed and then, 100g of sand is poured into the hopper
4) The hole of hopper is opened and let the sand flow out
5) The time taken for the sand flow out from the hopper is recorded
6) The procedure above is repeated by using different size of hopper and also sand.
Result:
Questions
1) What are the factors that influenced the powder flow?
-The factors influencing the powder flow such as particle size, size distribution, container surface effects, flow rate and the diameter of the container hole.
2) Based on the experiment above, which one the powder and hopper that give the best flowing reading?
The powder that give the best flowing reading is 150cc (size of sand) and the hopper that give the best reading is 1.6 cm (the diameter of hopper).
3) What are the methods/ways that can be used to help flowing of powder?
-The methods/ways that can be applied to help powder flow such as increased the diameter of hopper, reduced filling height powder, reduced cohesive strength of powder and utilized agitation or mechanical assistance.
Discussion
The widespread use of powders in pharmaceutical industry has generated a variety of method for characterizing the powder flow. In this practical, we want to see what will happen to the rate of flow based on different size and properties of sand and also hopper. From the result that we have obtained, we can say that 150cc (size of sand) and 1.6 cm (diameter of hopper) give the best flowing reading. This is because the resistance between the sand and the surface of hopper is reduced, making it easier to flow out from the hopper. However, there are some precaution steps that need to be taken during conducting this practical such as make sure do not shake the container (hopper) as it will affect the reading of flow rate, make sure there is no any obstacles especially at the hole of hopper and the experiment should be conducted in proper manner to ensure we can get the best result.
Conclusion
The various size and properties of sand together with the different size of diameter’s hopper will influence the rate of powder flow. The smaller the size of particle and the bigger the diameter of container, will resulting the highest the rate of powder flow.
References
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