The hot air required for the production of the air-flow rotary flash dryer is sent to the hot furnace through the blower, and the air is heated and divided into two paths into the dryer: one airflow is tangentially entered from the bottom side of the dryer to form a high-speed low-pressure rotary spouting airflow. The other air stream enters from the center of the bottom of the flash dryer, and the airflow rotary flash dryer forms a flowing air stream. The material enters the drying cylinder through the screw feeder and descends with the two air streams to carry out the heat and mass transfer process, the moisture is gradually removed, and the material is dried.

After the exhaust gas of the flash dryer is separated by the cyclone separator and the bag separator, the exhaust gas is discharged to the atmosphere by the induced draft fan, and the products are respectively passed through the cyclone separator, the bottom of the bag separator, and the star unloader. Discharge to the product storage tank. The rotating air stream is fluidized and transported to dry and the smaller particles are suspended in the swirling airflow, and are spirally raised by the rotating airflow. Under the action of the rotating force field, a large relative velocity is generated between the particles and the airflow, so that the heat and mass transfer coefficient is increased again. At the same time, under the action of centrifugal force and the rapid low pressure of the central airflow, the larger particles are spirally floated at different positions along the radius of the dryer, and the large particles are close to the wall of the cylinder, causing friction with the wall surface to make the particles Further micronization, the fine particles continuously flip, reducing the critical water content, shortening the diffusion distance of internal moisture to the surface, thereby still maintaining a large drying speed, and removing a part of the combined moisture in the material.

As the fine particles move along the spiral, the contact time of the material with the hot gas flow is increased, which creates favorable conditions for removing the combined moisture. The airflow rotary flash dryer flashes rapidly, and the dry wet material enters the dryer through the screw feeder, and the small particles rotate upward with the rotating hot air flow, and the larger particle clusters fall downward. A large relative velocity is generated between the solid particles and the hot gas flow, and the heat and mass transfer coefficient increases, so that the wet material mass rapidly removes moisture, and the dry material mass continuously collides, shears, and breaks under the action of the tangential hot air flow. To achieve micronization.

The airflow rotary flash dryer reduces the diffusion distance of moisture in the material on the one hand, and increases the gas-solid phase contact area on the other hand, which is beneficial to the vaporization of water in the material. In some of the larger particles, the falling speed of some particles is still greater than the sedimentation speed and continues to fall. In the inverted cone space, the velocity gradient of the hot air is established (the speed from the bottom to the top gradually becomes smaller, and finally becomes a fixed value), thereby ensuring The large particles in the lower part and the small particles in the upper part are in a fluidized state, which makes the material fluidized and dried, and accelerates the removal of water.

When the larger particles fall near the bottom gap, the high temperature, high speed negative pressure air flow drying with the bottom gap and the dry active area of ​​the vortex fluidized dry rotary flash dryer are thin, rotating near the wall, rotating in the gas layer The gas flow rate is high, and the gas flow rate is low at the center of the drying chamber, making it difficult to carry the particulate material out of the drying chamber. Therefore, a central air-lifting pipe is installed at the center of the bottom of the equipment to increase the degree of airflow turbulence. On the other hand, the fine particles after drying are swayed upwards to eliminate the "dead zone" of the original equipment and strengthen the drying of the central area. The granule material is smoothly taken out of the dryer, thereby increasing the production of the material, that is, the airflow drying area.

At the interface between the ascending airflow and the swirling airflow, the materials interfere with each other, collide with each other, form a vortex fluidized drying zone between the two airflows, and once again strengthen the drying. Due to the high-speed and low-pressure action in the central region, after the eddy current is fluidized and dried, the fine particles move toward the center and are carried out with the ascending airflow, while the fine particles dried in the swirling airflow are replenished to the vortex fluidization zone, greatly reducing the rotational fluidization zone. The concentration increases the hot air capacity, speeds up the heat and mass transfer process, and accelerates the vaporization rate of water. The axial superficial gas velocity is generally 3 to 5 m.s. The annulus wind speed in the hot air distributor is 30-60 m.s, and the gas velocity of the central air inlet should be three times the sedimentation velocity under the average particle size of the central portion.