Analysis of Discharge at the Collection Port for Plant Extract Spray Drying
The camera is aimed at the collection port of the plant extract spray dryer, capturing the real-time status of the powder inside the PE collection bag at a close range. From a professional process perspective, this video guides you to judge whether the current spray drying process is operating normally and whether key parameters need to be adjusted by observing the powder discharge status at the collection port.
Observe the Appearance and Color of the Powder
Normal Status: The powder is in a uniform fluffy state, with a natural color (such as light yellow, brownish yellow, etc., depending on the type of extract) and good fluidity. It remains loose and does not clump when held in hand.
Abnormal Warning: If the powder turns too dark or even black, it indicates that the temperature inside the tower may be excessively high, which poses a risk of degradation or coking of the active ingredients in the extract. It is necessary to appropriately lower the air inlet temperature or increase the feeding speed to shorten the residence time of materials in the tower.
Too Light or Whitish Color: It may indicate that the feeding concentration is too low or the drying temperature is insufficient, leading to high residual moisture. It is required to check the solid content of the concentrated liquid or appropriately raise the temperature.
Observe the Fineness and Fluidity of the Powder
Normal Status: The powder is fine, meets the required sieve mesh number, flows in a powdery state when poured out, and has no obvious large particles or lumps.
Coarse Powder with Granular Sensation: This may be caused by poor atomization effect (such as insufficient atomizer pressure, abnormal rotating speed) or excessively fast feeding speed that leads to inadequate atomization. It is necessary to check the parameters of the atomizer and appropriately reduce the feeding amount.
Severe Powder Adhesion and Clumping: This is mostly a manifestation of high moisture content of the discharged material. It is required to increase the air inlet temperature or reduce the feeding concentration/rate, and meanwhile check whether the air volume of the induced draft fan is normal.
Observe the Discharge Speed and Continuity
Uniform and Continuous Discharge: It indicates that the concentrated liquid feeding pump operates stably, the thermal balance inside the tower is good, and the process parameters are well matched.
Intermittent or Uneven Discharge: It may be caused by unstable pulsation of the feeding pump, fluctuation of the viscosity of the concentrated liquid, or risk of material adhesion and blockage inside the tower, which requires timely investigation.
Significantly Reduced Discharge or Even No Discharge: Be alert to blockage or material adhesion on the inner wall of the tower. It is necessary to shut down the equipment immediately to inspect the tower body, clean the attachments on the inner wall, and meanwhile review the settings of feeding concentration and temperature.
Comprehensive Judgment Combined with Parameters to Decide Whether Adjustment is Needed
| Observed Phenomenon | Possible Cause | Suggested Adjustment Direction |
| Black powder with burnt smell | Excessively high air inlet temperature | ↓ Lower the air inlet temperature, ↑ Increase the feeding speed |
| Damp and sticky powder | Insufficient temperature or too fast feeding | ↑ Increase the air inlet temperature, ↓ Reduce the feeding amount |
| Too light color with high moisture content | Too low concentration of concentrated liquid or insufficient temperature | ↑ Increase the solid content of the concentrated liquid, appropriately raise the temperature |
| Coarse particles with poor fluidity | Poor atomization or too fast feeding | Check the atomizer, ↓ Reduce the feeding speed |
| Intermittent discharge | Unstable feeding pump or viscosity fluctuation | Inspect the operation of the pump, adjust the temperature/concentration of the concentrated liquid |
Summary
The collection port of spray drying is not only a link for “collecting powder”, but also a window for real-time monitoring of the process status. Experienced operators can quickly judge whether the core parameters such as the feeding speed of concentrated liquid, the temperature of the spray tower and the atomization effect are reasonable by observing the color, fineness, moisture content and discharge rhythm of the powder in the PE bag, and make timely adjustments to ensure the stable and controllable quality of the final plant extract product.
