Overview of the dryer
Closed-circuit rotary flash dryer consists of drying mainframe, heater, cyclone separator, bag filter condenser, fan and pipeline. The whole drying process is carried out under the condition of very low oxygen content under the protection of nitrogen, with good product quality, avoiding the danger of oxidation, decomposition, combustion and explosion. This system can solve the organic solvent recovery, easy to oxidize and toxic materials drying problems, suitable for flammable, explosive and toxic cake-like, powdery materials and materials containing organic solvents drying and organic solvent recovery.
Closed-circuit rotary flash drying equipment working principle
Before the system is used, nitrogen is used to replace the air in the system so that the oxygen content in the system reaches the safe concentration of solvent. The circulating nitrogen is heated by the heating equipment and then enters into the flash dryer. Wet material from the conveying device into the flash drying equipment screw charging mechanism, the screw charger can be frequency conversion speed regulation. The material is conveyed into the drying and crushing room by the spiral, then it is crushed by the blades with different angles and rotated at high speed, and then it is impacted by the high temperature airflow into the cyclone drying room with high speed, and entrapped and rises up, at this time, the temperature of the airflow decreases rapidly, and the moisture in the material is evaporated rapidly so as to complete the drying process. The oversized material is blocked by the amalgamation ring and falls to the drying and crushing room to continue crushing until the fine powder is obtained.
The dried material enters the cyclone separator with high speed and high temperature airflow, at this time, more than 90% of the material is separated and sunk into the collection bin, and the remaining small amount of material enters the bag filter with the airflow. Airflow from the outside of the bag into the filter, filtered and discharged upwards, in order to prevent the bag from accumulating material, by the mechanical blowback bag blowing, reducing nitrogen consumption, the material yield can reach more than 99.5%.
The tail gas enters into the multi-stage condenser (finned condenser with small pressure drop and good condensing effect) to condense the solvent inside the hot and humid gas. The condensed solvent is collected by a collection tank and stored (zero emission into the air, can be recycled). After condensation and dehumidification, the dry nitrogen gas is sent to the heater through the blower for recycling.
Closed-circuit rotary flash vaporization dryer performance characteristics
(1) This technology adopts rotary flash drying equipment, the material is refined due to centrifugal, shear, collision, and was highly dispersed state, the relative velocity between the gas-solid two phases is larger, strengthened mass and heat transfer; hot air in the drying chamber produces a strong rotary movement, the material on the wall produces a strong scouring effect, eliminating the phenomenon of sticky wall.
(2)The material drying time is short, which ensures the material quality.
(3) The system is fully enclosed structure, equipment filled with inert gas (such as nitrogen), in the drying of anaerobic materials or solvents containing flammable and explosive nature of the material, so that there is no oxygen in the gas, can not be combusted or oxidized, you can effectively avoid the equipment in the production of fire or explosion accidents, so rotary flash drying equipment is safer than ordinary equipment.
(4)The system is sealed with nitrogen for all moving equipments, and the oxygen analyzer is used to analyze the oxygen content of the system online, which improves the safety of the system.
(5) Due to the closed-circuit operation, there is no exhaust gas and dust discharged into the atmosphere, so it will not cause environmental pollution.
Closed-circuit rotary flash vaporization dryer process flow chart
Optimized Design of Closed Circuit Rotary Flash Vaporization Dryer
In the closed loop flash drying process, the drying medium is generally inert gas, such as nitrogen or carbon dioxide gas. Heated high-temperature inert gas, into the dryer and the wet material for heat and mass exchange, the wet material is dried and separated by the cyclone separator and bag filter; humidity is larger and lower temperature inert gas into the condenser condensation dehumidification, lower humidity content of the inert gas from the blower into the heater to heat, and so on and so forth, to achieve a balanced drying cycle.
(1) Wet material adding
In the easy to leak at the feeding port, designed to micro-positive pressure to prevent atmospheric oxygen into it. If the general spiral feeder is used to feed the material, the feeding port spraying phenomenon is serious, the environment is very poor, artificial operation is not possible, the feeding is very abnormal. Therefore, the use of paddle staggered, bite each other double screw feeder, and in the silo on the configuration of closed discharge valve unloading, the formation of material sealing, eliminating the phenomenon of spraying, thus ensuring the feeding of uniformity, quantitative, continuous and stable.
(2) Circulation fan
The total resistance of the closed-circuit drying system is high, and in order to reduce the leakage inside and outside the system, the positive and negative pressures in the system cannot be high. The system fan is designed as two sets in series and placed separately, one is placed between the bag filter and condenser, and the other is placed before the heater. The shaft seal of the circulating fan has a large influence on the oxygen content of the drying medium, and the success or failure of the shaft seal design determines whether the whole system can operate normally. After research and analysis, in this case of high temperature, containing a certain amount of dust, poor lubrication conditions, the use of nitrogen sealing can get a better sealing effect.
(3) dry media dehumidification
Drying medium must be dehumidified and reach a low moisture content before recycling. Generally use the cooling method of dehumidification, cooling can be frozen liquid or cooling water, gas-liquid contact is sufficiently uniform, the effect is better.
(4) Sealing of mechanical rotating parts
There are many mechanical rotating parts in the drying system, such as air shutter, feeding machine, winch and so on. Their speed is not high, but there are many sealing points, such as sealing design is not good, the leakage of the system will be very large. The experimental use of double shut-off fan sealing effect is better.
Jiangsu Fanqun Drying Firm Equipment Factory Co., Ltd. products sell well all over the country, exported to the United States, Japan and Southeast Asian countries, welcomed by domestic and foreign users, the market reputation is excellent, but also China's drying equipment in the professional manufacturer of larger, more varieties of better quality of enterprises.
Complete scientific and quality system Professional technical team and superb technology Sophisticated production equipment
The company has large laser cutting machine, large water cutting machine, large plasma cutting machine, large automatic welding machine, non-destructive testing, mass spectrometer planer, bending machine, shearing machine and other high-end manufacturing and processing and inspection equipment.
Perfect after-sales service system
Pre-sales services :To provide you with project design, process design, suitable for your machine and equipment selection program development, according to your special needs, design and manufacture of products, for your training of technical operators.
Services during sale :Accompany you through the acceptance of the equipment and assist in the development of construction plans and detailed procedures.
After-sales service :The company sends technicians to the site to guide equipment installation commissioning site and training operators.
Flash Dryer,Flash Dryer manufacturer,Flash Drying equipment
