Spray drying systems are widely utilized in food & beverage, pharmaceutical, chemical, and plenty of other industries to produce fine and uniform micron size particles. Spray dryer needs massive quantities of hot air for drying. The quality of the final product (powder) is affected by the quality of inlet air coming into the dryer.
The Spray dryer mixes hot air with an atomized (sprayed) liquid stream in a drying chamber/atomizer that results in evaporation and produces free-flowing dry powder. The inlet air needs to be fresh and dry, freed from contamination and odourless. Since the ambient air changes throughout the year, the humid air can also enter the Spray dryer affecting its method. Thus, the drying temperature and time inside the dryer desires close observation to restrict loss because of variable humidity levels. These varying inlet conditions need to be monitored by an experienced operator to adjust the parameters for consistent output.
Effects of uncontrolled humidity
Due to high humidity, the powdered material tends to stick to the hopper conveyors and packing machine, resulting in frequent breakdowns in the conveyor drive mechanism. This hinders the free flow of powders/granules, making several downstream operations (e.g. packaging, filtering, and handling) difficult and expensive.
Some of the common problems faced by powder manufacturers are:
- Inconsistent powder quality
- Powder sticks to spray dryer walls
- Frequent breakdown of the spray drying system
- Increased drying cycle time
- Inconsistent powder quality
- Reduced throughput
KERONE has specially developed high-performance dehumidifiers for supplying controlled and consistent dehumidified air to the inlet point. This allows higher performance and output from spray dryers and improves the quality of the powder. Moreover, it reduces dependence on the operator for a constant adjustment of parameters on account of various outside atmosphere. It also reduces the energy consumption for heating the inlet air up to the desired temperature. Dehumidifying the inlet air also increases its temperature, as a results of that the heater should do less work to heat the air to the specified temperature.
Dehumidification of the air helps slurry to dry quick and allows smooth and free flow operations. Our Dehumidifier is usually recommended for humidity management because it continuously feeds dry air to the chamber, in spite of the ambient conditions, at a very low temperature. KESL desiccant Dehumidifier has successfully achieved the output in coffee powder spray drying unit. KERONE range of Dehumidifiers offer optimum drying at low temperatures for all powder. It should even be installed during the packaging and storage of powder to extend its shelf life.
Some of the Typical Spray Drying Applications
- Food Powder – Coffee, Spices and Seasoning, Fruits & Vegetables concentrate, Herbal Food, Milk, Tea, Spray Dried Eggs, etc.
- Industrial – Ceramic Material, Paint Pigments, Chemicals, etc.
- Pharmaceuticals – Antibiotics, Encapsulation, Enzymes, Vitamins, etc.
Why Humidity Control Matters in Spray Drying
Spray drying converts liquid feed into dry powder by exposing atomized droplets to hot air. The efficiency of this process depends heavily on the moisture-carrying capacity of the drying air.
- When humidity levels fluctuate:
- Drying efficiency drops
- Powder quality becomes inconsistent
- Operational issues increase
Maintaining controlled humidity creates stable drying conditions, regardless of seasonal or climatic changes.
Key Impacts of Poor Moisture & Humidity Control
1. Inconsistent Powder Quality
High humidity can lead to sticky powders, agglomeration, and uneven particle size. This affects flowability, packing, and end-use performance.
2. Reduced Drying Efficiency
Moist air absorbs less water, increasing drying time and energy consumption while lowering overall throughput.
3. Wall Deposition & Product Loss
Excess moisture causes semi-dried particles to stick to chamber walls, resulting in product loss, frequent cleaning, and reduced uptime.
4. Shorter Shelf Life
Hygroscopic products such as milk powder, herbal extracts, enzymes, and pharmaceuticals can reabsorb moisture, impacting stability and shelf life.
Where Humidity Control Makes the Biggest Difference
Inlet Air Treatment
Dehumidified inlet air ensures consistent evaporation and improved drying performance throughout the year.
Feed Moisture Optimization
Controlled feed solids reduce drying load and improve powder uniformity.
Exhaust Air Monitoring
Real-time humidity monitoring allows precise control of outlet moisture and product quality.
Post-Drying & Packaging Areas
Humidity control prevents moisture pickup during powder handling, storage, and packing.
Benefits of Effective Moisture & Humidity Control
- Consistent product quality
- Higher yield and recovery
- Reduced energy consumption
- Lower maintenance and cleaning downtime
- Compliance with GMP and food safety standards
Moisture and humidity control are not just auxiliary considerations in spray drying—they are core process parameters that directly impact efficiency, quality, and profitability. By investing in the right air handling, dehumidification, and monitoring systems, manufacturers can achieve stable spray drying operations across all seasons.