Related Experiment Video
Updated: Jun 4, 2026

08:21
Forming Micro-and Nano-Plastics from Agricultural Plastic Films for Employment in Fundamental Research Studies
Published on: July 27, 2022
Flow of Formulation Granules through a Conical Hopper.
B Mazumder1, R Rajan, Jasmina Khanam
1Department of Pharmaceutical Technology, Jadavpur University, Kolkata-700 032, India.
Indian Journal of Pharmaceutical Sciences
|March 4, 2011
Summary
This study investigated pharmaceutical granule flow rates through conical hoppers, finding that mass flow depends on granule properties and hopper angle. A new equation accurately predicts flow, aiding pharmaceutical manufacturing processes.
Area of Science:
- Pharmaceutical Sciences
- Chemical Engineering
- Materials Science
Background:
- Understanding powder flow is critical for efficient pharmaceutical manufacturing.
- Granule properties and hopper geometry significantly influence flow behavior.
- Existing models may not fully capture the complex interactions during gravity flow.
Purpose of the Study:
- To investigate the gravity flow characteristics of pharmaceutical granules in static conical hoppers.
- To determine the influence of granule properties, lubricants, and cone angles on mass flow rate.
- To develop and validate a predictive equation for granule flow rate.
Main Methods:
- Studied gravity flow of pharmaceutical granules with varying properties (active pharmaceutical ingredients, binders, diluents) in static conical hoppers.
- Investigated the effect of lubricants (magnesium stearate, colloidal silicon dioxide) on mass flow rate.
- Developed a new dimensionally analyzed equation to predict granule flow rate.
Main Results:
- Mass flow rate is dependent on granule properties and hopper cone angles under controlled environmental conditions.
- Lubricant addition (magnesium stearate, colloidal silicon dioxide) affects mass flow rate.
- The developed equation demonstrated good agreement with experimental data, with a deviation of ±10%.
Conclusions:
- Granule flow through conical hoppers is predictable using a dimensionally analyzed equation.
- The equation provides a valuable tool for optimizing hopper design and pharmaceutical powder handling.
- Further research can explore dynamic flow conditions and a wider range of materials.
Related Concept Videos
Pumped Concrete
Concrete in large quantities can be pumped across long distances for placing in inaccessible sites. This system comprises a hopper that receives concrete from a mixer, a pump to propel the concrete, and pipelines that facilitate its delivery.
For direct-acting pumps, the concrete enters the pump via the inlet valve under the action of gravity and suction created by the movement of the piston. This concrete is then forced into the pipeline and out through the outlet valve by the forward movement...
For direct-acting pumps, the concrete enters the pump via the inlet valve under the action of gravity and suction created by the movement of the piston. This concrete is then forced into the pipeline and out through the outlet valve by the forward movement...
Design Example: Aggregate Gradation
The right type and quality of aggregates are crucial for concrete as they significantly influence its properties, mix proportions, and cost-effectiveness. If different sources are available for sand, the commonly used fine aggregate in concrete, the selection of sand is primarily based on its gradation.
The grading, or particle-size distribution, of sand is determined using sieve analysis, with standard sizes ranging from 150 μm to 10 mm (ASTM No. 100 sieve to 3⁄8 in. sieve). Sand is sampled...
The grading, or particle-size distribution, of sand is determined using sieve analysis, with standard sizes ranging from 150 μm to 10 mm (ASTM No. 100 sieve to 3⁄8 in. sieve). Sand is sampled...
Placing Concrete
The concrete is placed as close as possible to its final position to avoid segregation. The placed concrete is then fully compacted to expel the entrapped air, and the next layer of concrete is laid while the underlying layer is still in the plastic state. The rate at which concrete is placed and compacted is kept equal.
While placing concrete, care is taken to ensure that the concrete is laid in uniform layers, and hand shoveling and moving concrete using poker vibrators is avoided. Also,...
While placing concrete, care is taken to ensure that the concrete is laid in uniform layers, and hand shoveling and moving concrete using poker vibrators is avoided. Also,...
Precipitate Formation and Particle Size Control
In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species.
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
Mixing Concrete
Concrete mixing ensures a homogenous blend where aggregates are well-coated with cement paste. Concrete mixing is typically done using two main types of mixers: batch and continuous. Batch mixers handle one batch at a time, thoroughly combining materials before discharging and receiving the next batch. In contrast, continuous mixers receive a steady flow of ingredients, mixing them consistently and discharging without interruption. Within batch mixers, tilting drum mixers mix with internal...
Flow Table Test
The flow table test is an established method used to assess the workability of concrete, particularly useful for evaluating highly flowable concrete mixes. This test employs an apparatus that consists of a wooden board topped with a steel plate, collectively weighing 35 pounds. The board is connected to a base via a hinge and measures 27.6 inches on each side.
Concrete is placed within a truncated cone mold that is 8 inches high with an 8-inch base diameter and a 5-inch top diameter. The...
Concrete is placed within a truncated cone mold that is 8 inches high with an 8-inch base diameter and a 5-inch top diameter. The...

