Sealed circulation spray dryer works in a seal circumstance. The drying gas is usually inert gas, such N2 . It’s applicable for drying material with organic solvent, toxic gas and the material easy to be oxidized. adopt inert gas as circulation gas, so to protect the material to be dried. The inert gas circulates after dehumidification process. N2 is heated and then enters into drying tower. Liquid material is conveyed to centrifugal nozzle by screw pump, and then it’s atomized into the liquid mist by the atomizer, the heat transferring process is finished in the drying tower. The dry product is discharged at the bottom of tower, the evaporated organic solvent is sucked by the vacuum generated by the fan. Power or solid material will be separated in the cyclone and sprinkling tower. The saturated organic gas is drained out after it’s condensed in the condenser. The gas not condensed recycles in the system after it’s heated continuously. Ordinary normal centrifugal spray drying process is realized by air conveying and exhausting process. This is the obvious difference between explosion proof type sealed circulation centrifugal spray dryer and ordinary centrifugal spray dryer. The drying media in drying system is N2 , the interior is under positive pressure. To keep positive pressure stable, the pressure transmitter controls the inlet amount of N2 automatically.
1.The system technology of the equipment is designed for explosion proof in the main body and key parts of the equipment as to ensure the safety of equipment operation.(The system to the volatile toxic and harmful gas has not explosive device.)
2 In the system it has condensing system and solvent recovery system to the solvent of the liquid material .the recovery system can make second processing the solvent in the drying solution and let the solvent recycle , thus greatly reducing the production cost.
3.For the heating system for the machine , it is very flexible. we can configure it based on the customer site conditions such as steam ,electricity , gas furnace and so on , all of them we can design it to match our spray dryer.
4. The feeding pump , atomizer ,blast fan and the suction fan are with the inverter.
5. The main parameters such as the inlet temperature , main tower temperature and outlet temperature are adjusted by the temperature meter . The machine has the main tower pressure testing point , air inlet pressure testing point , air outlet pressure testing point, the oxygen testing point and so on . Once machine run , you can see everything clearly .and very convenient for the user to operate it . The main electrical components are international brand and which can ensure the electrics run reliable and safely.the Electrical control are adopted sequential interlock interlock, super temperature, fault alarm and other measures to ensure the safe operation.
6. The inlet temperature are controlled,displayed and alarmed by the intelligent digital thermometer to ensure constant inlet temperature.
7. The outlet temperature value are specified through the inverter adjusting the feeding rate.
8. the main control points as bellow:
⑴To adjust the diaphragm pump by inverter or manual to control the The liquid flow rate;
⑵The speed of the atomizer are controlled by the inverter( control the line speed and particle size), with oil pressure control and alarm system;
(3)Air inlet has the temperature control system and pressure display device ;
(4)The blast fan use inverter to control the are rate and air pressure ;
(5)The suction fan use the inverter to control the air rate and air pressure , and control system pressure ;
(6)The system has the Nitrogen implementing and empty device ;
(7)The system has the device for testing the Nitrogen as to ensure the equipment run smoothly and safely;
(8)The cloth bag filter has pulse blowing-back system;
(9)The outlet air has the temperature control system and pressure display device ;
(10)The condenser has liquid level control system;
(11)Air-liquid separator has the liquid level control system;
For the sealed-circulation centrifugal spray drying machine , it is suitable for drying the solution, emulsion, suspending liquid and pasty liquid containing organic solvents, volatile poisonous and harmful gas, material easily oxidized and afraid of light and needs to be solvent recovery . It not only inherits all the advantages of centrifugal spray drier , but also there is no powder flying outside when drying operation . It can achieve 100% material collecting rate.Through the solvent recovery system ,the collected solvent through secondary processing , it can be recycled, which greatly reduces the production cost. Favored by the majority of users, which is widely used in the pharmaceutical, chemical, food and other industries drying operation.
dried powder collecting: ≥95%
remanent dissolvent: ≤2%
oxygen contents: ≤500ppm
explosion-proof of electric components: EXDIIBT4
system condition: positive pressure
1.Liquid name and property: solid contents (or water contents), viscosity, surface tension and PH value.
2. Dry powder density residual water contents allowed, particle size, and maximum temperature allowed.
3. Output: shift time daily.
4. Energy that can be supplied: steam pressure, electricity properly, fuel of coal, oil and natural gas.
5. Control requirement: whether or not the inlet and outlet temperatures should be controlled. Powder collection requirement: whether it’s necessary to use cloth bag filter and the requirement of the environment of the exhausted gas.
6. Other special requirements.