If the temperature difference range of the heated workpiece is required to be controlled in a small range, the heating area of the parts is bound to be reduced, and the effective area of the corresponding furnace chamber should also be reduced, the furnace can not work at full load, resulting in a waste of energy and man-hours, and the unit consumption of the product will also increase, so the average temperature area of the chamber furnace must be expanded as much as possible. The specific methods are:
1. The furnace door is equipped with an electric heating element, which can increase the temperature at the furnace door and improve the temperature uniformity of the furnace. In the process of temperature uniformity test, the temperature of a certain test point is low from the test data, and the heating current of the resistance wire is adjusted to make the temperature uniformity of the furnace temperature meet the process requirements.
2. Along the length of the furnace, the power (resistance wire) should be reasonably arranged, and some power can be increased at the furnace mouth, and the grouped partition control method can also be adopted.
3. Set up a fan to force the gas convection of the furnace, which can greatly improve the uniformity of the furnace temperature.
4. Improve the paint color of the furnace shell, the object color is different, its emissivity is also different, according to the experimental furnace shell sprayed silver gray or black paint, the heat dissipation of the outer space of the furnace can be reduced.
5. Improve the temperature control system and adopt appropriate furnace temperature adjustment methods. PXR type temperature control instrument is adopted, and the control mode is changed to PID continuous control mode, and the furnace temperature uniformity can meet the requirements of the production process after replacing the analog instrument.
