The pressure spray dryer is equipment that can complete drying and granulation simultaneously. The system adopts a co-current pressure spray drying tower. Inside the drying chamber, droplets and hot air flow in the same direction. The pressure and flow rate of the feed pump as well as the nozzle orifice size can be adjusted according to process requirements to obtain spherical particles with the required fixed size ratio.
Working Principle
After heating, the drying air is delivered by the supply fan and enters the tower through the hot air distributor at the top of the drying tower. Materials to be dried are fed into the spray gun by a high-pressure pump and atomized into fine droplets under high pressure. Inside the drying chamber, hot air contacts the droplet clusters; moisture evaporates and materials are dried into dry powder, which is collected at the bottom of the main tower and by the cyclone separator.
The moisture-laden exhaust gas is discharged to the atmosphere by the induced draft fan after dedusting via a wet scrubber.
Technical Parameters
Product Features
● Feeding and Atomization System
Consists of feed pump, pressure stabilizer, high-pressure pipeline valve assembly and spray gun nozzle assembly.
Our company provides optional orifice plates and vortex inserts of multiple specifications for machine commissioning to meet customers’ requirements on material particle size. The complete set of spray gun nozzles enables precise positioning of nozzles inside the stainless steel drying chamber. The spray guns are mounted downward from the upper part of the drying chamber. At proper positions, the connecting ring of the fixing device allows quick and easy disassembly for nozzle inspection.
● Hot Air System
Composed of primary, medium and high efficiency air filters, supply fan, steam heat exchanger, hot air ducts and other components.
The steam heat exchanger adopts new finned heat exchange tubes with base tubes of Φ18×2 stainless steel and tightly wound thin stainless steel fins. The outer frame is also made of stainless steel. The special fin structure creates convective turbulence when air passes through the heat exchanger to improve heat transfer efficiency.
● Drying System
Consists of hot air distributor, main drying tower, observation manhole, in-tower lighting device, pneumatic rapping hammer and other parts.
Located at the top of the drying tower, the DCK-type hot air distributor features a special distribution structure for even hot air inlet into the drying tower, avoiding turbulence and chaotic airflow. It ensures sufficient and uniform contact with high-pressure atomized droplets with minimal dead zones, improving consistency of the drying environment. It is made of 304 stainless steel with thickness δ=2 mm.
● Product Collection System
Composed of two-stage cyclone separators, rotary discharger, induced draft fan, connecting pipelines, etc.
The product collection system extracts gas from the drying tower, recovers products and discharges exhaust gas into the atmosphere. It separates fine powder from exhaust gas for clean emission and maximizes finished product recovery.
Since bag filters are unsuitable for powder collection due to product characteristics, two-stage cyclone separators are adopted to raise dust collection efficiency.
● Airflow Cooling System
Composed of air dehumidifier, air conveying pipeline, two-stage cyclone separator, material collector, air pump and other components.
Solid powder after drying has a relatively high temperature and cannot be packaged directly, so cooling is required. This system is configured so that products can be pneumatically conveyed, cooled and then continuously fed into silos for packaging.
● Control System
PLC automatic control system.
It includes detection, display and alarm of major control points.
Product Applications
The pressure spray dryer is suitable for:
Chemical industry: Organic catalysts, resins, synthetic laundry powder, oils, ammonium sulfate, dyestuffs, dye intermediates, white carbon black, graphite, ammonium phosphate, etc.
Food industry: Amino acids and analogues, seasonings, proteins, starch, dairy products, coffee extracts, fish meal, meat extracts, etc.
Pharmaceutical industry: Chinese patent medicines, pesticides, antibiotics, herbal granules, etc.
Ceramics: Magnesium oxide, porcelain clay, various metal oxides, dolomite, etc.
Also applicable for various fertilizers, alumina, ceramic powder, pharmaceutical materials, heavy metal superhard steel, granular laundry powder, Chinese patent medicines;
Amino fatty acids, paraffin, glycerides, tallow, etc.
It is also widely used in spray crystallization, spray concentration, spray reaction and other processes.