The airflow dryer utilizes high-speed hot air flow to suspend wet starch in it. It has the characteristics of high heat transfer coefficient, large heat transfer area, and short drying time. Airflow drying, also known as "instant drying", is the application of dilute phase transport in solid fluidization for drying. This method involves direct contact between the heating medium and the solid particles to be dried, and suspending the solid particles in the fluid, resulting in a large contact area between the two phases and enhancing heat and mass transfer processes. It is widely used in the operation of drying units for bulk materials.

In the drying operation, the air flow rate, air inlet and outlet temperatures, and feeding amount in the dryer are mainly controlled. The feeding amount is used as a dependent variable for adjustment. Below, the editor will briefly introduce the solutions to common problems in the operation and use of air flow dryers, as follows:

1. If the system pressure suddenly increases and cannot be eliminated, the power should be cut off immediately, and the operator should quickly leave the operation site to prevent personal injury during explosion.

2. When there is a sudden and prolonged power outage, the dryer should be cleaned to prevent the wet material inside from drying out and becoming hard, blocking the dryer ring gap, and affecting product quality when restarted.

3. When the system pressure is unbalanced, check whether there is any air leakage or blockage in the system, and whether the pressure measuring tube is blocked.

4. If the explosion-proof valve suddenly opens during the operation, personnel must be evacuated within the specified time and the induced draft fan must be turned off first before turning off the feeder.

5. When the inlet temperature of the gas is constant and other conditions are normal, slowly increase the speed of the feeder to increase the feeding amount and reduce the outlet temperature of the gas to the required temperature when the outlet temperature of the gas is high; On the contrary, when the gas outlet temperature is low, it affects the moisture content of the dry product, so the screw feeder speed is reduced, the feed amount is reduced, and the gas outlet temperature is raised to the required temperature.

6. When the inlet temperature of the dryer gas is high and the negative pressure inside the drying tower is low, the feeding rate must be reduced until the negative pressure inside the tower stabilizes before readjusting the feeding rate to ensure that the outlet temperature is at the design value.

7. When the gas outlet of the bag filter emits powder, check whether the bag is detached or damaged, and replace or repair it in a timely manner.

Through the above content, we hope it will be helpful for everyone to understand the airflow dryer.