FLP Series Bottom Spray Fluidized Bed Granulator and Coating Dryer

FLP series fluidized bed granulator and coater is a widely adopted granulation and drying equipment internationally. It is suitable for the mixing, granulation, and drying of powdered materials and finds extensive applications in pharmaceuticals, food processing, chemical, and light industries.

All parts of the FL series fluidized bed granulator and dryer that come in contact with materials are made of stainless steel. It utilizes silicone rubber inflatable sealing rings for sealing and features dual-flow spray guns to control particle size. Mixing, granulation, and drying are completed within the same enclosed container, ensuring rapid and efficient operation while preventing dust dispersion, leakage, and contamination.

The FLP Series Bottom Spray Fluidized Bed Granulator and Coating Dryer boast an elegant design, low air resistance, no dead corners, easy cleaning, and compliance with GMP requirements.

Name1

Name2

Name3

Applications and Scope of Use for FLP Series Bottom Spray Fluidized Bed Granulator and Coating Dryer

Pharmaceutical Industry:

Granulation: Granules for dispensing, capsule granules, powder granules, and various heavy granules.

Coating: Granules, pill coatings, tablet coatings.

Food Industry Granulation:

Sugar, coffee, cocoa, powdered juice, seasonings, wheat starch, etc.

Powder Metallurgy and Ceramic Industry Granulation.

Pesticides, Feed, and Fertilizer Granulation and Coating.

Catalyst Granulation and Coating.

Pigments, Colorants, and Dye Granulation.

Granulation of Other General Chemicals. 

Granulation: Improve disintegration, enhance compressibility, increase density, and round the surface of granules.

Pelletizing: Increase density, produce spherical particles, high-efficiency pills, and smooth the surface of granules.

Encapsulation and Coating: Solution and suspension encapsulation, powder encapsulation, high-efficiency pills, concentrated particle size distribution, and increased density.

Coating: Film coating, enteric coating, sustained-release coating, and hot-melt coating.

FLP Series Bottom Spray Fluidized Bed Granulator and Coating Dryer parameter

Bottom spray fluidized bed granulator Video

The granulation process of FLP series bottom spray fluidized bed granulator

The granulation process of FLP series bottom spray fluidized bed granulator is a technique initially developed abroad. It involves the injection of binder through nozzles to agglomerate materials, forming granules in a fluidized state. Depending on the specific process requirements, the position and direction of spray nozzles vary, typically in three positions: tangential spraying, primarily used for pelletizing, granulation, coating, and encapsulation; bottom-up spraying, mainly employed for high-performance coating and encapsulation; top-down spraying, commonly utilized for drying, granulation, and certain coating processes. This series of equipment represents a versatile fluidized bed granulation apparatus designed to perform drying, granulation, coating, pelletizing, and encapsulation within the same unit.

Moreover, various provisions are available including material conveying, control systems, solvent recovery, on-site cleaning, and dust removal systems, ensuring flexibility and excellent applicability. The system comprises several main components: the air delivery system, the main body, and the blower. Air enters the main body through the air delivery system after undergoing various treatments. The air delivery system mainly consists of filters, heaters, humidifiers, and dehumidifiers. The main body is composed of inlet ducts, process components, and filter chambers, all fixed on supporting columns on both sides. Inlet air enters the main body through inlet ducts and is evenly distributed via a screen below the material trough. The upper part of the main body houses the filter chamber, equipped with two identical filter bags, each installed within a separate sealed filter chamber. Air exits the main body through the filter chambers. Regulation of airflow is achieved through an exhaust air damper mounted on top of the blower. This "dual filter chamber system" ensures continuous fluidization as when one filter bag is being cleaned of accumulated dust, the other can pass all the fluidized air. During the removal of accumulated dust, a sealed exhaust air damper prevents gas flow, allowing dust to return to the material trough.

(1) The bottom spray system is a critical component of fluidized bed coating machines, often referred to as the bottom spray system.

The bottom spray system, often referred to as the bottom spray system, is a critical component of fluidized bed coaters. It creates an ascending zone in the center of the fluidized bed and a descending zone in the annular gap, resembling a fountain, which transforms random fluidization into regular flow, making it suitable for industrial coating operations. Developed in 1992, the bottom spray process represents the most advanced generation of bottom spray technology. This patented technology ensures large batches, enhances efficiency, and for the first time enables coating of particles smaller than 50μm without agglomeration. The bottom spray process device consists of a conical material trough with a cylindrical partition ring inside. Different types of sieve plates with various openings are installed at the bottom of the trough to distribute airflow states inside and outside the partition ring. The largest opening area is located directly below the partition ring, allowing most of the fluidized air to flow to this area, ensuring sufficient airflow for material movement. There is a certain gap between the partition ring and the sieve plate to facilitate smooth flow of material from the outside to the inside of the partition ring. Material inside the partition ring moves into the expansion chamber due to the thrust of the incoming airflow. As the material's own gravity overcomes the gradually weakening thrust, it falls outside the partition ring, forming a cyclical flow state. The coating liquid is introduced into the system through pneumatic atomizing nozzles installed at the center of the sieve plate. The nozzles spray liquid from bottom to top, in the same direction as the movement of the material. When atomized liquid droplets come into contact with particles inside the partition ring, they adhere and spread on the particle surface. As the particles fluidize into the expansion chamber, excess moisture from the coating liquid evaporates. The ordered fluidization state ensures uniform and continuous coating film thickness, which is a crucial factor in controlled-release formulations.

(1) The bottom spray fluidized bed for powder coating combines fluidization with air transport, forming an ascending zone at the center and a fluidized zone around the perimeter. Due to the higher air velocity in the ascending zone, the powder remains highly dispersed, preventing agglomeration, thus facilitating powder coating with the bottom spray fluidized bed. Achieving a "fountain" effect with the bottom spray bed is essential for effective coating and depends on factors such as the flowability of the material, particle size, thermophysical properties, and a reasonable ratio of airflow between the ascending and fluidized zones.

(2) Coating of granules (or pellets) is primarily carried out using bottom spray or side spray fluidized beds. Granules intended for coating must meet basic requirements including adequate strength, small surface area, minimal microporosity, and a dense surface. Therefore, granules or pellets intended for coating should be prepared using a rotary fluidized bed. Applications include: 1. Ordinary film coating with water-soluble or organic solvents for polymer materials. 2. Sustained-release and controlled-release coating. 3. Enteric coating. 4. Coating of fine particles (50μm or smaller). 5. Encapsulation of active pharmaceutical ingredients.

(2) The top spray device consists of a conical material trough and an expansion chamber.

Due to the conical shape of the trough and its angled walls, material fluidization within the trough is vigorous. Incoming airflow drives the material upward into the expansion chamber. As the diameter of the expansion chamber is larger than that of the trough, the airflow velocity in the expansion chamber is lower than that within the trough, resulting in less intense fluidization of the material in the expansion chamber. Once the material's own gravity overcomes the upward thrust of the incoming airflow, it falls back into the trough, thus completing a continuous cycle of movement throughout the production process. However, the fluidization state is irregular and lacks strict control.

A fluidized bed is an excellent drying apparatus. During fluidization, particles are suspended in air, allowing for complete contact between the particle surface and the hot air, thereby achieving optimal heat exchange. This ensures uniform heating of particles and even evaporation of excess moisture, preventing localized overheating. When the material temperature slightly exceeds room temperature, higher inlet air temperatures can be used to accelerate the drying rate. During granulation or coating processes, liquid is introduced into the system through pneumatic atomizing nozzles. Multiple nozzle mounting points are available on the expansion chamber, allowing for adjustment of nozzle height. In granulation processes, to ensure uniform particle size distribution, the spray gun's spray range should match the maximum range of material fluidization. During coating processes, the spray gun should be positioned to spray into the densest area of particle movement, minimizing the distance between coating droplets and particles, facilitating optimal spreading of droplets on the particle surface to form a uniform film.

Maintenance and Overhaul of FLP Series Bottom Spray Fluidized Bed Granulator

Regular inspection and maintenance of the entire set of equipment are necessary to ensure optimal performance, normal operation, and cleanliness. Instruments and meters should be kept dry, and the area surrounding the equipment should be regularly cleaned.

Compressed Air Filter:

Every 6-12 months, disassemble the filter and thoroughly clean all parts with a soft brush. Remove accumulated water from the bottom before each operation.

Oil Mister:

Add edible vegetable oil every 15 days to ensure timely lubrication of the solenoid valve.

Air Compressor:

After each shift, remove condensation water from the tank. Weekly, use organic solvents to thoroughly clean parts to prevent clogging.

Cloth Bag:

Check the permeability of the cloth bag regularly. If clogged, clean it immediately. When stopping the machine or changing varieties, clean it promptly.

Perforated Plate:

If the perforated plate becomes blocked, it will cause channeling during powder fluidization, leading to poor fluidization. Clean it promptly if clogged.

Inlet Air Filter:

If the filter becomes clogged, it will severely reduce the inlet air volume, leading to deteriorated fluidization. Therefore, it should be cleaned or replaced every 2-3 months.

Filter Screen:

The sieve screen on the material cart must be cleaned after each shift to prevent material from blocking the mesh holes and affecting the penetration of hot air.