As the core equipment integrating drying and granulation, spray drying granulator is widely used in pharmaceutical, food and chemical fields. Its operation must strictly follow standardized procedures to ensure particle uniformity, yield, and equipment stability. This paper takes the pressure spray drying granulator as an example to analyze its core operating steps.
1、 Preparation and inspection before startup
1. Equipment integrity inspection: Check whether the tower body, cyclone separator, pipeline and other components are clean and free of residue, and whether the sealing ring is intact. Confirm that the bag filter has been installed and secured to prevent dust spillage due to air leakage.
2. Gas and circuit debugging: Start the air compressor, adjust the pressure to 0.6-0.7MPa, and drain the condensed water in the pipeline. Check if the electrical cabinet instruments (ammeter, voltmeter, temperature controller) are normal, and set the inlet air temperature (such as 160-180 ℃ commonly used in the pharmaceutical industry).
3. Preparation of raw materials and auxiliary materials: Prepare adhesives according to process requirements and pre fill them into the feed pipe through a peristaltic pump. Check the height of the spray gun (1.5-2m from the bottom of the tower) and the atomization pressure (0.2-0.4MPa) to ensure even spraying.
2、 Startup and operation parameter control
1. System startup: Turn on the fan, adjust the air damper to the 2/3 position, and turn on the heating system after the current stabilizes. After preheating to the inlet air temperature standard, start the atomizer and adjust the speed to the highest (such as 50000rpm).
2. Feed and granulation control: Gradually turn on the peristaltic pump, adjust the feed rate (such as 5-20ml/min), and observe the fluidization state inside the tower until the material particles are suspended in the middle of the sight glass. Sample and detect particle size every 30 minutes, and optimize particle size distribution by adjusting the spray speed and inlet air temperature.
3. Process monitoring: Real time recording of inlet air temperature, outlet air temperature (target value 50-60 ℃), atomization pressure and other parameters. If wall sticking phenomenon is found, immediately reduce the feed rate and increase the inlet air temperature.
3、 Shutdown and maintenance
1. Normal shutdown: Turn off the peristaltic pump and switch to pure water cleaning of the spray gun for 10 minutes. Wait until the outlet temperature drops below 60 ℃, turn off the heating system and fan, and finally turn off the air compressor and drain the pipeline pressure.
2. Equipment cleaning: Disassemble the bag filter and use compressed air to blow back to clean the accumulated powder. Disassemble the spray gun and rinse the atomizing disc with clean water using a screw pump to avoid residue crystallization and blockage.
3. Regular maintenance: Replace lubricating oil every 200 hours and check the wear of high-speed gears and bearings. Clean the powder accumulation at the bottom of the tower after each batch of production to prevent cross contamination.
The operation of spray drying granulator needs to take into account the accuracy of process parameters and the standardization of equipment maintenance. By standardizing processes and real-time monitoring, particle yield (up to 96-98%) and quality stability can be significantly improved, providing efficient and reliable granulation solutions for industries such as pharmaceuticals and food.
