It is very important to accurately measure, control and record the temperature of zinc bath.

1. Temperature measurement

Nickel chromium/nickel aluminum thermocouple (k index) is commonly used as temperature sensor to measure the temperature of zinc liquid. In order to prevent the corrosion of zinc liquid on the thermocouple, it is necessary to use the same material as the boiler wall to make a protective sleeve. One end of the pipe is sealed, and the thermocouple is inserted from the other end. The thermocouple measuring points are usually arranged at the four corners of the zinc pot 10~20mm away from the pot wall. The sheathed thermocouple shall be suspended in the zinc liquid, and the support or fixed frame of the thermocouple sleeve shall be convenient for installation and removal without affecting the hot galvanizing operation. Regular ash and slag removal is very important for accurate measurement of zinc bath temperature.

When a new zinc pot is heated, the recorded temperature often lags behind the actual temperature in the pot, and can be gradually equal until the zinc ingot starts to melt.

For gas fired or oil fired furnaces, it is often recommended to place two temperature measuring thermocouples (generally distributed at the diagonal position of the zinc pot) in the zinc pot, which are connected to different temperature controllers to control the heating of zinc steel at the same time. For electric heating furnace, two thermocouples can also be installed on the unheated side wall and bottom of the zinc pot.

Errors often occur in temperature recording and measurement. The main reasons for errors are: thermocouple damage or short circuit; The temperature measuring instrument is uncorrected and has errors; The compensation wire is wrongly wired, or the model of the compensation wire is wrongly selected, or the general wire is wrongly used to replace the compensation wire. Regularly check the circuit and regularly check the nuclear instruments.

2. Temperature control

The temperature of zinc liquid shall be controlled, recorded and adjusted by special equipment, with alarm and protection functions. The control and alarm devices can be connected to a certain position of the personnel on duty to ensure continuous monitoring and regulation.