Small-Scale Experimental Closed-Loop Spray Dryer QFN-BL-D1

1. Equipment Introduction:

The unit is specifically designed for organic solvents, utilizing an inert gas medium formed by circulating nitrogen to replace the conventional air medium for spray drying. In addition to recovering the product, it can also recover organic solvents. Given the low flash point, slight toxicity, and flammable/explosive characteristics of organic solvents, this closed-loop circulating spray system has been specially designed.

1.1 Explosion-proof System:

First layer - nitrogen explosion-proof: Based on the inert gas properties of nitrogen, the entire pipeline adopts nitrogen circulation, and the system can only operate normally when the oxygen content is below 3%.

Second layer - industrial control explosion-proof: When pressure exceeds 3000 Pa, the safety valve opens to release pressure. For detailed industrial control procedures, please consult the factory's technical engineers.

Third layer - rupture disc explosion-proof: When the pressure inside the drying tower system rises abnormally, the rupture disc at the top of the tower automatically opens to relieve the explosion.

Fourth layer - whole-unit explosion-proof: Equipped with an internal ventilation system (optional), suitable for hazardous gases.

1.2 Product Features:

Prevents oxidation and avoids hazards;

Easily achieves aseptic and dust-free operation.

Enables recovery of solvents from the feed liquid.

Improves the retention of aromatic components.

Capable of drying or cooling granulation of combustible feed liquids.

Capable of drying feed liquids with extremely high thermal sensitivity.

Achieves low pollution or zero pollution.

Eliminates the need for deodorization devices.

Enables low-temperature drying below 100°C.

1.3 Applicable Products:

Non-oxide ceramics, superhard alloys, high-performance battery materials.Seasonings, health foods.Pharmaceuticals, vitamins, organic drugs.Synthetic resins, waxes, etc.

2、Overall Structure (subject to Qiaofeng's design)

The equipment mainly consists of: feed system, heating system, atomization system, spray drying system, inert gas circulation system, product recovery system, and condensation system.

2.1 Feed System

Components include: mixing tank, solvent tank, peristaltic feed pump, feed piping, and atomizer. First, the prepared slurry is placed into the mixing tank and stirred evenly. Under the drive of the peristaltic pump, the slurry passes through the piping and valves to reach the atomizer. The atomizer must be equipped with Shanghai Qiaofeng's specially manufactured explosion-proof atomizer nozzle, with a nozzle service life warranty of one year.

2.2.2 Heating System

The heating system consists of a nitrogen-electric heating system. The enclosed heating elements directly heat the drying medium (nitrogen) within the pipeline, and a set of voltage-regulating control devices maintains temperature accuracy within ±2°C.

2.33 Drying Tower

The drying tower includes: tower body, explosion-proof lighting, gas distributor, temperature control equipment, pressure relief device, inlet air piping, outlet air piping, oxygen content measurement sensors, and other components. A filtration device must be installed inside the inlet air piping. After atomization, the slurry is heated by the hot air, completing evaporation and drying to become powder that falls to the bottom discharge outlet, while the gas is discharged through the exhaust pipe into the closed-loop circulation pipeline.

2.4 Product Recovery System

The gas discharged from the bottom of the drying tower contains powder and organic solvent vapor. A filtration device is used for recovery, separating the powder from the organic solvent gas. The powder is recovered, and the organic gas enters the condenser for recovery and reuse.

2.5 Gas Circulation System

The gas circulation is accomplished by a circulation fan. The drying medium is output from the circulation fan, flows through the condensation unit, electric heater, drying tower, cyclone separator or bag filter, high-temperature-resistant high-efficiency filter, and then returns to the circulation fan for reuse, forming a gas circulation system.

2.6 Condensation System

The condensation system consists of a refrigeration unit, condenser, refrigerant circulation pump, filter, heat exchanger, and connecting piping. The “wet” gas (containing evaporated organic solvent vapor) discharged from the dust collector enters the condenser. After being cooled and de-liquidized in the condenser, the gas returns to the gas circulation system. The organic solvent vapor is condensed and recovered, then automatically discharged into the solvent tank through the level controller at the bottom of the condenser.

2.7 Atomization System

This system adopts mechanical hard-contact construction with no sealing gaskets and no leakage. Unlike ordinary electric centrifugal nozzles, overheated corrosive vapor in prolonged contact with the wires of electric nozzles can corrode the wires, causing the plastic insulation layer on the wire surface to corrode, soften, and detach, thereby forming a short circuit.

3、Advantages of This Equipment: 

3.1 Adopts Qiaofeng's innovative (QFN-BLG-ES-VER2018-1A) atomization system. This system adopts mechanical hard-contact construction with no sealing gaskets and no leakage. Unlike ordinary electric centrifugal nozzles, overheated corrosive vapor under positive pressure in prolonged contact with the wires of electric nozzles can corrode the wires, causing the plastic insulation layer on the wire surface to corrode, soften, and detach, thereby forming a short circuit. 
3.2 Capable of producing ultra-fine powders in the 1-8 micron range, suitable for battery material preparation.

4、Equipment Parameters:

注1: Ethanol evaporation rate based on inlet air temperature of 140°C 2: For equipment requiring a larger evaporation capacity, please inquire online or contact our company