According to the survey, the application of electric heaters in the industrial field is becoming increasingly widespread. They are an efficient and energy-saving heating, warming, and viscosity reducing equipment in industries such as petroleum, machinery, chemical, printing and dyeing, shipbuilding, and power. They have replaced traditional methods such as oil, coal, and steam heating. And this type of electric heater has been widely used in the industrial field.

Its heating element is made of an alloy, and its thermal strain characteristic of its own resistance allows it to automatically adjust its heating power. It adjusts the dynamic heating power according to the process design temperature, heats the catalyst medium passing through the equipment pipeline, thereby improving the activity of the catalyst, producing more types of products, and improving economic efficiency. However, this type of electric heater may also experience different malfunctions during use. Therefore, in order to promptly handle the faults and ensure its normal operation, it is necessary to master the working principle of this type of electric heater proficiently. Below, the author of China Electric Heater Network will briefly introduce the working principle of the electric heater: this electric heating element is a triangular wiring, a temperature sensor is installed at the outlet of the electric heater, a thermocouple is a temperature measuring element, and the temperature can reach up to 800 degrees. The process adjustment of heating power is mainly achieved by controlling the conduction angle of the bidirectional thyristor in the voltage regulation module to adjust the output voltage of the voltage regulation module, thereby changing the power of the heater.

When the process requires starting the heater, first turn on the power switch and ensure that the emergency stop point is closed. Without any fault alarm, press the start button to close the contactor and the upper end of the voltage regulation module is energized. The medium temperature detection device can detect the temperature of the medium in the equipment. After the temperature signal is converted into a current signal by the medium temperature transmitter and sent to the emergency stop normally closed point, it is compared with the basic heating temperature signal set by the process. The control signal is sent to the computer intelligent controller of the voltage regulation module to control the bidirectional thyristor conduction angle and adjust the output voltage of the module to change the power of the heater, achieving the purpose of controlling the medium temperature.

When the set temperature is reached, the heater will enter a constant temperature state. During the heating process, the overheating temperature controller will detect the temperature inside the heater through the electric heating element and send the internal temperature signal of the equipment to the control system through the control node. The heat tracing distance is used to measure and display the temperature of the medium, providing power to the temperature signal device. At the same time, the measured temperature signal of the medium is sent to the control system, which compares and calculates the temperature of the medium and the temperature of the thermal element, and automatically sends a control signal to the pressure regulating module to control the output power of the heater. When the electric heater malfunctions during operation, it should be checked, analyzed, and dealt with as quickly as possible. Otherwise, it will affect the medium temperature and catalyst activity, and affect the quality of the polymerization product. Below, I will briefly explain some common troubleshooting methods.

Troubleshooting methods:

1) Use a multimeter to measure whether the main circuit power supply is normal and check if the higher-level power supply is sent out.

2) Open the voltage regulation module and check if the module circuit board is functioning properly. Replace the voltage regulation module and fuse.

3) Use a multimeter to measure the DC voltage level of the relay coil to see if there is DC power. If there is no power, it indicates that the emergency stop normally closed point is not closed. Notify the instrument to cooperate with the inspection.

4) When the fault alarm relay is activated, the fault alarm light will light up and there will be an audible alarm. If the overheating temperature controller is overheating, the electric heater should be stopped from being used until the temperature drops, and the relevant equipment should be further inspected. If there is an internal fault alarm in the voltage regulation module, usually caused by electronic component burnout, it should be replaced with spare parts of the same model as soon as possible to ensure production needs. If the medium temperature measuring device malfunctions and alarms, the on-site temperature probe should be checked and replaced.

5) When the voltage regulation module does not receive the control signal, a specialized clamp ammeter for measuring current signals should be used for measurement, or any wire on the voltage regulation module should be removed. The multimeter should be set to the current range and connected in series between these two wires to see if there is a current signal sent. If not, notify the instrument personnel to cooperate with the inspection.

6) Remove the three-phase power supply input line from the electric heater body, measure the internal insulation resistance of the electric heater with a megohmmeter to see if it is normal, and measure the internal resistance of the electric heater with a multimeter to see if it is balanced. If the resistance is balanced, it means that there is no disconnection inside the electric heater.