In the actual drying operations, the selection of fans mainly involves the following several situations.
1. Choose appropriate fan models for the newly-built drying project;
2. Because of the demand for increasing production and other factors, it needs to determine the fan improvement scheme to the existing drying system;
3. Proofread the capacity of the fan when its running condition changes.
For the first case, it is mainly in accordance with the production ability and resistance of the drying system to determine air volume, flow rate and total pressure head of the fan. For a single induced draft fan system, it should ensure that the total pressure of the fan is greater than the resistance of the system. While for the double blowing - inducing fan system, the sum of total pressure of the two sets of fans should be greater than system resistance. When choosing fans, it generally depends on the fan curve to decide what type of fan can well meet the required operating conditions of the drying system, so as to make the fan efficiency achieve the highest.
The second case generally requires to determine the variable range of air volume and thereby determine the fan improvement scheme according to the actual production demands.
In the third case, when the air temperature surrounding the fan changes, especially when the actual temperature is lower than the designed temperature to much, the motor is likely to run overloaded and even to be burnt out when serious.
