Main Systems of Centrifugal Spray Drying Equipment

Based on my many years of experience in spray drying design, I have summarized a few key points below. Please feel free to correct me if I’m wrong.

1. Main Systems:

a. Feed System: This system generally consists of a feed tank, feed pump, feed piping, valves, and hoses. For the feed pump, options typically include peristaltic pumps, screw pumps, and piston pumps. Key Point: Feed stability is crucial, as it directly affects the stability of the entire system and the final moisture content of the product. Currently, feed control is divided into two types: electromagnetic speed regulation and variable-frequency speed regulation. To ensure feed stability and overall system controllability, our company generally employs fuzzy control tracking technology for the feed pump, which significantly improves both feed stability and the final moisture content of the product. We recommend using variable-frequency speed regulation with tracking capability. (We generally use pumps from Hangzhou Slate.)

b. Air Inlet System: This system generally consists of a heat source heater, a blower, primary and intermediate-efficiency air purification filters, hot air ducts, high-temperature-resistant high-efficiency air purification filters, and a hot air distributor. The heat source heating method agreed upon by your company is a combined steam and electric heating system. Key considerations include material purification requirements, equipment manufacturing costs, and operating costs.

c. Atomization System: This system consists of an atomizer (or several spray guns). The centrifugal atomizer comprises components such as an atomization motor, atomization spindle, gears, and atomization disc. Our atomizers are designed in-house and manufactured off-site; they utilize variable-frequency control to adjust the atomizer’s rotational speed based on material characteristics and processing capacity, with a speed range of 0–36,000 rpm. The main shaft undergoes special treatment, with a guaranteed service life of 7,000 operating hours; in actual use, it can reach 16,000 operating hours. The gears are from a Swiss brand. The design of the atomizing discs incorporates advanced technologies from Okawara and Niru; different types of atomizing discs (with square, round, rectangular, and linear holes) are designed to meet the specific requirements of each material, and materials include stainless steel, ceramic, and others.

d. Drying System: This system consists of the main drying tower, tower top, cold air jacket, anti-blowback device, wall-adhering air device (or purging device), air hammer, support platform, and other components. Key Points: The tower diameter, straight section height, and conical section angle are professionally designed based on material characteristics, processing capacity, operating temperature, and other factors; components such as the cold air jacket, anti-backflow device, wall-adhering air device (or purging device), and air hammers are also professionally designed according to the specific material conditions. These technologies represent a forward-looking approach within the industry.

e. Product Collection System: This system consists of cyclone separators (large and small), piping, vortex valves (airlock valves), refrigerated dehumidifiers, induced draft fans (large and small), and cyclone supports (depending on the material, the system may utilize a product air-conveyance cooling system or single-stage or multi-stage cyclone separators).

f. Dust Removal System: This system employs a wet dust removal method, which consists of a spray tower (support platform), water tank, magnetic drive pump, piping (typically flexible hoses), and vent outlets;

g. Control System: This system comprises a control cabinet, airflow control, pressure control, temperature control, and programs for tracking and correcting various variable parameters. Currently, the industry lacks sufficient understanding of the parameters of the entire equipment system within the control system, making it difficult to ensure comprehensive control. Key point: Temperature, pressure, and airflow must be monitored at various locations to control the entire system. (Pressure monitoring at locations such as the air inlet, inside the tower, and in the cyclone separator, etc.)