Spray System (Nozzles & Manifold)

The spray system is a critical component of a rotary granulation drum, responsible for the controlled application of liquid binders, coatings, or solutions onto the tumbling bed of powder or seed particles. It consists of a manifold that distributes the liquid from a central supply to multiple nozzles, which atomize the liquid into a fine spray. This ensures uniform wetting and agglomeration of particles, which is fundamental to the granulation process for achieving consistent particle size, density, and product quality. The system is designed for integration into rotary drums used in chemical manufacturing, where precise liquid addition is essential. The manifold acts as a distribution header, channeling liquid to nozzles mounted at strategic points along the drum's interior. Nozzle count typically ranges from 4 to 12, depending on drum size and coverage requirements. Spray angles vary from 60 to 120 degrees, affecting droplet distribution and wall wetting. Droplet size, measured as Sauter Mean Diameter, ranges from 50 to 500 micrometers, with smaller droplets preferred for fine coating applications. Operating pressure is typically 1.0 to 1.6 MPa, though this standard is for verification, not certification. Flow rate per nozzle ranges from 0.5 to 5.0 L/min, influencing total liquid addition and residence time. Operating temperature should be maintained between 10 and 80 degrees Celsius to prevent seal degradation and viscosity changes. Wetted parts are commonly made of stainless steel (e.g., 316L) or PTFE for aggressive chemicals, with material grades referenced to ASTM A240. Manifold diameter ranges from 25 to 80 mm, and length from 500 to 3000 mm, affecting pressure drop and flow distribution. Connection types include flanged (DIN 2633) or threaded (ISO 228), chosen based on pressure and maintenance needs. The total weight of the assembly is typically 15 to 60 kg. All values are directory reference ranges and must be confirmed for the specific model and application with the legal manufacturer or supplier.

Liquid is pumped under pressure from a supply tank into the manifold. The manifold acts as a distribution header, channeling the liquid to individual spray nozzles mounted at strategic points along the drum's interior. The nozzles, often of an atomizing type (e.g., pressure-swirl, two-fluid), break the liquid stream into a fine mist or spray pattern. This spray is directed onto the cascading bed of material inside the rotating drum, where the droplets coat particles and initiate agglomeration through liquid bridging.