Optimization of Droplet Granulation Process for HNS-IV Explosives Utilizing Pulsed Air-Jet Shear Technology.

Area of Science:

• Chemical Engineering
• Materials Science
• Process Chemistry

Background:

• Precise control over droplet size and generation frequency is crucial for granulation processes, especially for energetic materials like HNS-IV.
• Traditional liquid-liquid biphasic systems often lead to volatile organic solvent accumulation and complex waste management.

Purpose of the Study:

• To develop a novel droplet granulation strategy for HNS-IV with independent and precise control over droplet injection frequency and volume.
• To investigate the influence of process parameters on particle size and morphology.
• To evaluate the environmental and safety benefits compared to existing methods.

Main Methods:

• Utilized pulsed air-jet shearing technology for granulation.
• Systematically adjusted air pressure, frequency, duty cycle, and liquid flow rate to control droplet characteristics.
• Controlled suspension flow rate to achieve specific median particle sizes (D50).
• Investigated the effect of calcium alginate concentration on particle sphericity and thermal decomposition.

Main Results:

• Achieved precise control over droplet injection frequency and volume.
• Successfully controlled primary particle size, yielding median sizes of 375.84 μm, 444.45 μm, and 504.22 μm.
• Demonstrated that calcium alginate concentration impacts particle sphericity and thermal decomposition behavior.
• Significantly reduced volatile organic solvent accumulation compared to biphasic systems.

Conclusions:

• The pulsed air-jet shearing method provides a highly controllable, greener, and safer approach for HNS-IV granulation.
• This technique offers advantages in reducing solvent waste and simplifying residual solution management.
• The methodology serves as a valuable reference for granulating various energetic materials with enhanced precision.