Common faults of hot air circulation oven

Understand whether the heated items in the hot air circulation oven are placed too intensively, whether the high-temperature filter is blocked, and whether the air volume regulating plate is changed After eliminating these reasons, judge whether the circulation fan has faults, which causes the circulation of the hot air circulation is not good and the hot and humid air cannot be discharged normally Secondly, from the analysis of the fault phenomenon and the circuit principle of the oven, the oven can be heated, indicating that the output signal of gcd-23a intelligent computer temperature controller is normal, and the input and output signal of PLC is also normal After the above fault analysis, it can be concluded that the control signal and adjustable components are normal, and then check from the following aspects (1) check the PID adjustment parameters of gcd-23a intelligent computer temperature controller to see if the setting parameters are changed due to human error operation, so as to make the system operate abnormally PID parameters directly affect the regulation accuracy of the system, which is the core content of the control system design With proper PID parameters, PID control can calculate the control quantity of the system according to the error characteristics of the controlled process of the system, and obtain the corresponding output response characteristics by using proportion, integral and differential The control system can achieve satisfactory control effect Restore the normal setting value of PID parameter Secondly, check whether the circulating fan operates normally and whether the steering direction is correct If the fan reverses or the fan load is too large and the rotation speed is too slow, the hot air circulation will not be smooth When the fan reverses, the power supply of the fan can be switched between any two phases; when the speed of the fan is too slow, check from two aspects: (1) whether the power supply voltage is normal in electrical aspect, and whether there is phase loss or winding open circuit (2) in terms of machinery, check whether there are faults such as bore sweeping, vibration, bearing overheating, damage, fan blade loosening, case cleaning, etc It can be excluded according to the specific situation Check the solid-state relay and heater for local open circuit again Solid state relay (SSR), abbreviated as "SSR", is a new type of contactless switching device composed of all solid-state electronic components It uses the switching characteristics of electronic components (such as switching triode, bidirectional thyristor and other semiconductor devices) to achieve the purpose of making and breaking the circuit without contact and spark, so it is also called "contactless switch" SSR successfully realizes the control of weak signal (VSR) to strong current (output load voltage) Due to the partial open circuit after virtual connection or conduction of SSR, the 380V power supply is lack of phase and the heater cannot be heated completely The treatment method is to repair or replace the solid-state relay The partial open circuit of the heater will make the heating unable to work completely, causing the heating process to be too slow Repair or replace the heater Deal with the problem completely Close the air switch of the circulating oven, run the program according to the operation instructions of the oven After 2.5h heating, the oven reaches the set temperature, the time relay starts to count, and the oven enters the stage of intermittent heating and sterilization After 1 h of heat preservation, the oven began to cool down, and after 2.3 h, the whole drying and sterilization cycle was finished, which fully met the technical and technological parameters requirements provided by the oven.