In the production of pharmaceutical raw materials, antibiotics will become inactive when dried at high temperatures; In the preparation of lithium battery materials, ternary slurries are prone to oxidation and spontaneous combustion when exposed to air; In the field of fine chemicals, the handling of materials containing toxic solvents is not only afraid of leakage pollution, but also afraid of solvent waste and increased costs——Traditional drying equipment often encounters safety risks, cost control, or quality loss when facing these "high demand" materials.

Changzhou Lima's latest closed cycle spray dryer relies onThe core feature of "inert environment closed-loop+efficient solvent recovery" has accurately solved the drying problem of flammable, explosive, easily oxidizable, thermally sensitive, toxic and high value-added materials, gradually becoming a key equipment in manufacturing fields such as lithium batteries, pharmaceuticals, and fine chemicals.

1 Application field

Because of its unique closed design that does not directly exchange with the external environment, the closed cycle spray dryer is particularly suitable for handling materials containing organic solvents, sensitive to oxygen, toxic or irritating, and requiring the recovery of high-value solvents. Its main application areas include:

1. Drying of organic solvent system materials:

· Chemical industry: Synthetic resins, dyes, pigments, pesticides, catalysts, fine chemicals, etc.

· Pharmaceutical industry: Antibiotics, liposomes, microspheres, drug intermediates, etc. use organic solvents such as methanol, ethanol, acetone, dichloromethane, etcProducts extracted or synthesized using DMF.

2. Drying of easily oxidizable or oxygen sensitive materials:

· Food industry: High value nutritional supplements (such asDHA, ARA microcapsules, natural pigments (such as carotenoids), flavor compounds, plant extracts, etc.

·Biotechnology: Thermosensitive and easily inactivated biological products such as probiotics, enzyme preparations, proteins, etc.

3. Drying of toxic, harmful or irritating materials:

·Ceramic industry: Some ceramic powders containing toxic binders.

· Chemical industry: Prevent the leakage of toxic dust, protect operators and the environment, such as certain pesticides and special chemicals.

4. Processes that require solvent recovery to reduce costs and meet environmental requirements:

·Almost all occasions where expensive or valuable organic solvents are used, closed-loop systems can achieve solvent recovery of up to 98% or more, significantly reducing production costs and subsequent environmental treatment pressures.

5. Safe production of flammable and explosive materials:

·By injecting inert gas (such as nitrogen) as a drying medium, oxygen is eliminated, fundamentally eliminating the risk of combustion and explosion.

II Technical highlights of equipment and its matching use

Closed loop spray dryer is more than simple'Closed', its technological highlights are reflected in systematic engineering design and intelligent control:

1. Design of fully enclosed circulation system:

·The entire drying process is carried out in a fully enclosed inert gas (such as N)₂）Conducted in an environment with zero contact between materials, solvents, and external air to ensure safety and quality.

2. Efficient solvent condensation recovery device:

·One of the core components. Using a low-temperature condenser, the organic solvent vapor evaporated during the drying process is efficiently condensed into liquid and recovered. The recycled solvent has high purity and can be directly reused in the previous process, greatly reducing material costs and waste liquid treatment costs.

3. Explosion proof and inerting system:

·Integrated explosion-proof design: The equipment body, pipeline, cyclone separator, silo, etc. all adopt explosion-proof design (explosion-proof motor, explosion-proof lamp, explosion-proof electrical control, explosion-proof pipe, etc.).

·Automatic oxygen content monitoring and control system: Two sets of high-precision oxygen content sensors are installed in the system to monitor the oxygen concentration in the circulating gas in real time. Once the concentration exceeds the preset safe value (usually<3%), the system will automatically replenish inert gas to ensure that it is always in a safe state.

4. Self cleaning technology:

·For certain resin or thermoplastic materials that are prone to sticking to walls, the system can be equipped with a dry ice or solvent jet automatic cleaning device to regularly and automatically remove the tower wall powder, ensuring the stability and product yield of continuous production. It can also be used for cleaning work after a batch of products is completed.

5. Intelligent Process Control System (PLC/HMI):

·Adopting advanced PLC and touch screen human-machine interface, achieving one click start stop and full process automation control.

·Real time monitoring and recording of key process parameters: inlet/outlet temperature, system pressure, oxygen content, fan frequency, pump speed, etc., to ensure process reproducibility and comply with regulatory requirements such as GMP/FDA.

·Equipped with fault diagnosis and safety interlock functions to ensure the safe and reliable operation of equipment.

In summary, the nitrogen protection closed cycle spray dryer has the characteristics of high efficiency, safety and environmental protection. Although its initial investment and operating cost is higher than that of the open system, its value in ensuring product quality, safety and environmental compliance is the core process equipment for drying such materials.

In the future, with intelligent continuous manufacturing and digital transformation, it will drive its transformation fromUpgrading from "optional solutions" to "mandatory solutions" is a key technological direction for future green, efficient, and intelligent continuous manufacturing.