For the drying of volatile organic solvents that are toxic or can cause harm to people and the environment after escaping, the organic solvents or products contained in the liquid are easily oxidized, flammable, and explosive materials. Generally, materials that require this process cannot come into contact with oxygen gas, so inert gases (such as nitrogen, carbon dioxide, etc.) are mostly used as heat carriers; This method is also known as inert gas drying. The exhaust gas discharged from the dryer, after gas-solid separation, also needs to go through a condenser to recover solvents or remove moisture, and then enter the dryer for recycling after being heated by a heater. By means of heat carrier and closed cycle, we can effectively avoid the danger of high temperature during material drying, prevent contact with oxygen during spray drying, and recover more than 90% of dust.

Ganlin/closed cycle spray dryerAt present, it has been maturely applied to ethanol, acetone, hexane, NMP,DMF， Closed circuit circulating spray drying process for products with inert gas (or nitrogen) as the drying medium for suspension made of organic solvents such as organic solvents. The entire process is oxidation free, the medium is recyclable, and the inert gas (or nitrogen) can be recycled. The closed cycle system designed for organic solvent recovery has extremely high requirements for explosion-proof control, high system self-control performance, and strict GMP requirements. It is commonly used for spray drying of precision ceramics, pharmaceuticals, battery materials, hard alloy (Wc. Fe) powder. Flow diagram Closed cycle spray dryer system consists of spray dryer host, heater with air filter, blower, moisture separator, large and small cooling towers, spray tower, exhaust fan, primary cyclone separator, secondary cyclone separator, pump, oxygen detector, pipeline and control valve.

The equipment is mainly composed of feeding system, heating system, atomization system, spray drying system, inert gas circulation system, product recovery system and condensation system. Overall dimensions: length<1.6 meters, width<1.2 meters, height<1.6 meters;
Feeding system
The feeding system includes: batching tank, solvent tank, and feeding peristaltic systemPump, feeding pipeline, atomizer, first put the prepared slurry into the batching tank, stir evenly, and then drive the peristaltic pump to reach the atomizer through the pipeline valve. The atomizer needs to be equipped with a specially designed explosion-proof atomizer nozzle from Shanghai Qiaofeng, and the nozzle has a one-year warranty for use.Closed low-temperature organic solvent spray dryer manufacturer direct sales
Heating system
The heating system consists of a nitrogen electric heating system. The enclosed heating element directly heats the dry medium (nitrogen) in the pipeline and controls the temperature accuracy within ± 2 ℃ through a set of pressure regulating control devices. The maximum temperature of the heater is 110 ° C.
drying tower
The drying tower includes: tower body, explosion-proof lighting, gas distributor, temperature control equipment, pressure relief device, air inlet pipeline, air outlet pipeline, oxygen content measurement sensor and other components. A filtering device needs to be installed inside the air inlet pipeline; The atomized slurry is heated by hot air, and the slurry evaporates and dries into powder, which falls to the bottom through the discharge port. The gas is discharged from the exhaust pipe for closed-loop circulation. The material of the drying tower is 304 stainless steel.
Product recycling system
The gas discharged from the bottom of the drying tower contains powder and organic solvent vapor, which are recovered by a filtering device to separate the powder and organic solvent gas. The powder is recovered, and the organic gas enters the condenser for recovery and reuse.
gas-circulating system
The gas circulation is completed by a set of circulating fans. The drying medium is output from the circulating fans, flows through the condensing device, electric heater, drying tower, cyclone separator or bag filter, and then returns to the circulating fans for reuse, forming a gas circulation system.
condensing system

The condensation system consists of a refrigeration unit, a condenser, a refrigerant circulation pump, a filter, a heat exchanger, and connecting pipelines. The "wet" gas (including evaporated organic solvent vapor) discharged from the dust collector enters the condenser, and the gas is cooled by the condenser to remove liquid before returning to the gas circulation system. The organic solvent vapor is automatically discharged into the solvent tank through the liquid level controller at the bottom of the condenser after being condensed and recovered. The condensation temperature is ≤ 12 ℃