Changzhou Shinma Drying Engineering Co.,LTD.

The Closed Loop Spray Dryer Machine operates within a fully sealed environment, utilizing inert gas – typically nitrogen – as the drying medium. This makes the Closed Loop Spray Dryer Machine ideal for processing materials containing organic solvents, emitting toxic gases, or those prone to oxidation.

Within this Closed Loop Spray Dryer Machine, nitrogen is heated and enters the drying chamber. The liquid feed is delivered to a centrifugal atomizer, which disperses it into fine droplets. The subsequent heat and mass transfer occurs instantly in the chamber, with dried powder collected at the bottom. The evaporated solvent vapors are carried by the circulating gas through a cyclone separator and spray scrubber for dedusting. The saturated solvent gas is then condensed into liquid for recovery in the Closed Loop Spray Dryer Machine's condenser, while the non-condensable gas is reheated and recycled as the drying carrier.

A key distinction of this Closed Loop Spray Dryer Machine is its dehumidification method. Unlike conventional spray dryers that continuously exhaust air, this Closed Loop Spray Dryer Machine maintains a sealed, pressurized nitrogen environment. A pressure transmitter automatically controls N2 intake to sustain a positive pressure, ensuring system integrity and material protection. The Closed Loop Spray Dryer Machine thus allows for complete reuse of the inert gas medium, offering a safe, efficient, and cost-effective drying solution.

(1) The connection of each pipeline in the closed system adopts a unique sealing structure with good airtightness, which can ensure that the system has no leakage under a pressure of 0.2MPa and has high thermal efficiency;

(2) The nitrogen-protected Closed loop spray dryer uses inert nitrogen as the drying medium gas, which is anti-toxic, anti-oxidative and anti-explosive. The gas can be recycled after moisture loading and dehumidification;

(3) The system is equipped with a condensation system and a recovery system for the solvent of the drying liquid, which can enable the solvent in the drying liquid to be recycled through secondary treatment. The material is dried (solvent removal) in a closed state and nitrogen environment in a hot state and the solvent is recovered through the condenser. The whole machine has high safety. At the same time, the equipment is a fully enclosed design with a high material recovery rate. The high recovery rate of this equipment system is unattainable by other types of dryers. Main technical indicators: dry powder material recovery rate ≥ 95%, product residual solvent ≤ 2%, which greatly reduces production costs;

(4) The drying speed of the nitrogen-protected Closed loop spray dryer is very fast. After the liquid is sprayed, the surface area increases. In the high-temperature airflow, 95%-98% of the water can be evaporated instantly. The drying time is generally only about 5-40 seconds;

(5) Spray drying is usually used to treat solutions with a moisture content of 40%-60%. It can be dried into powder products at one time. Most products do not need to be crushed and screened after drying, thereby reducing production processes and simplifying the production process. At the same time, the product has good dispersibility, fluidity and solubility. Since the drying process is completed in the air, the product can maintain a spherical shape similar to that of a droplet and has good fluidity.

(6) The Closed loop spray dryer equipment has an online system pressure test device, an online oxygen concentration detection and control device, and an in-situ cleaning device;

(7) The Closed loop spray dryer machine control system adopts a human-machine interface, that is, PLC+touch screen control, and a dynamic display of the process flow chart. The particle size, bulk density and moisture content of the product are within a certain range and can be adjusted by changing the operating conditions, which is relatively convenient to control.

Application of Closed loop spray dryer

(1) The moisture in the material is an organic solvent and needs to be recovered;

(2) There is a risk of combustion or explosion when the solvent contained in the solid comes into contact with air;

(3) The solid is easily oxidized when it comes into contact with oxygen during the drying process;

(4) Prevent the mixing of fine particles during drying;

(5) There is odor or toxic components discharged after drying, which pollutes the environment;

Dry powder recovery rate ≥95%

Product residual solvent ≤2%

System oxygen content ≤500PPM

Electrical explosion-proof EXDIIBT4

Equipment system positive pressure state