Closed loop spray dryer

NegotiableUpdate on 01/06

Model

Nature of the Manufacturer: Producers

Product Category

Place of Origin

Online Consult

Overview

Closed cycle spray dryer. The closed cycle spray drying system works in a closed environment. The drying medium is inert gas, usually N2, which is suitable for drying materials containing toxic gas or materials prone to oxidation during the drying process.

Product Details

The closed circulation centrifugal spray dryer system is rarely used in the domestic pharmaceutical industry. Its characteristics: the heat carrier forms a closed circulation loop in this system, which is conducive to saving the heat carrier, recovering organic solvents, and preventing toxic substances from polluting the atmosphere. The materials commonly used in the pharmaceutical and chemical industry are often materials containing organic solvents, or materials that are easily oxidized, flammable, explosive, and some may even be toxic. When using a closed cycle system, most of the heat carriers are inert gases (such as nitrogen, carbon dioxide, etc.). The exhaust gas discharged from the drying tower is removed of fine particles by cyclone and wet dust collectors, and then enters the condenser. The function of the condenser is to condense the solvents (or moisture) in the exhaust gas, and the condensation temperature must be below the dew point of the highest allowable concentration of the solvent to ensure the condensation effect. After dehumidification, the exhaust gas is pressurized by a fan and enters an indirect heater before being turned into hot air, which is repeatedly reused.

　　Working principle of closed cycle spray dryerreason

The closed cycle spray drying system works in a closed environment. The drying medium is inert gas, usually N2, which is suitable for drying materials containing toxic gas or materials prone to oxidation during the drying process.

After being heated by a heater, nitrogen enters the drying tower, and the liquid material is transported to the centrifugal nozzle by a screw pump. The liquid is atomized into droplets by a high-speed rotating centrifugal atomizer, and the heat and mass exchange process is completed in the drying tower. The dried powdered material is discharged from the bottom of the tower. The evaporated organic solvent gas, under the action of a fan, removes the dust trapped in the gas through a cyclone separator and a spray tower. The saturated organic solvent gas is condensed into liquid by the condenser and discharged from the condenser. The non condensable gas medium is continuously heated and reused as a drying carrier in the system. The conventional conventional centrifugal spray drying achieves the purpose of moisture removal through continuous air supply and exhaust, which is also an obvious difference between explosion-proof closed centrifugal spray drying equipment and conventional centrifugal spray drying equipment;

Among them, the drying medium in the drying system is N2, and the internal operation is positive pressure, maintaining a certain positive pressure value. If the internal pressure drops, the pressure transmitter will automatically control the N2 inlet to ensure system pressure balance. Due to the use of inert gases such as N2 as circulating gas, it has a protective effect on dry materials. The circulating gas undergoes processes of moisture loading and removal, and the medium can be reused.

Advantages of closed cycle spray dryer:

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

(2) Using inert nitrogen as the drying medium gas, it is resistant to poisoning, oxidation, and explosion. The gas can be reused after being loaded and dehumidified;

(3) The condensation system and recovery system equipped with a solvent for drying the material liquid in the system can enable the solvent in the drying material liquid to be recycled through secondary treatment. The drying of the material (solvent removal) is completed in a closed state and nitrogen environment in a hot state, and the solvent is recovered through the condenser. The safety of the whole machine is high. At the same time, the equipment is designed to be fully enclosed, with a high material recovery rate. The high yield of this equipment system cannot be achieved by other types of dryers. Main technical indicators: dry powder material recovery rate ≥ 95%, product residual solvent ≤ 2%, thereby greatly reducing production costs;

(4) The drying speed is very fast. After spray, the surface area of the feed liquid increases. In the high temperature airflow, 95% -98% of the moisture can be evaporated instantly, and the drying time is generally about 5-40sec;

(5) Spray drying is usually used to treat solutions with moisture content of 40% -60%, which can be dried into powder products at one time. Most products do not need to be crushed and screened after drying, thus reducing the production process and simplifying the production process. At the same time, the product has good dispersibility, flowability, and solubility. Due to the drying process being completed in air, the product naturally maintains a spherical shape similar to droplets and has good flowability.

(6) The equipment is equipped with a system pressure online testing device, an oxygen concentration online detection and control device, and an in-situ cleaning device;

(7) The equipment control system adopts a human-machine interface, namely PLC+touch screen control, and the process flow chart is dynamically displayed. The particle size, bulk density, and moisture content of the product can be adjusted by changing the operating conditions within a certain range, which is relatively easy to control.

　　closeroadApplication of circulating centrifugal spray dryer

(1) The moisture in the material is divided into organic solvents and needs to be recovered;

(2) There is a risk of combustion or explosion when solvents in solids come into contact with air;

(3) During the drying process, solids are prone to oxidation when they come into contact with oxygen;

(4) Prevent bacterial contamination during drying;

(5) After drying, there is an odor or toxic components emitted, which pollutes the environment;

　　Technical Specifications:

Dry powder recovery rate ≥ 95%

Product residual solvent ≤ 2%

System oxygen content ≤ 500PPM

Electrical anti riot EXDIIBT4

Positive pressure state of equipment system