In on-site operation and maintenance, the following situation is often encountered: after the furnace has been in service for a period of time, the quality of workpieces at the edge of the furnace chamber is inconsistent with that of workpieces in the center, or the temperature control instrument shows that the set temperature has been reached while the actual workpiece temperature is still low. Such problems are often not caused by damage to the heating elements, but by a mismatch among the power margin, furnace chamber dimensions, and loading method during the selection stage. For operation and maintenance personnel, understanding the selection logic can reduce the number of furnace shutdowns more effectively than repeatedly adjusting parameters afterward.
This equipment has a rated power of 45 kW and a maximum working temperature of 950°C, and is suitable for medium-temperature heat treatment and sintering processes. During selection, the heating rate requirements and holding time for the workpieces should first be clarified, and then the heat load corresponding to the loading quantity should be calculated. If the power is too low, the heating time will be prolonged; if the power is too high, the temperature field in the furnace chamber will fluctuate. Both increase the workload of operation and maintenance adjustments. The heating elements are resistance wire elements configured for the 950°C operating condition, and their replacement cycle is related to the actual load in the furnace.
The furnace chamber dimensions can be customized according to user requirements. Operation and maintenance personnel should pay attention to two points: first, leave a reasonable spacing between the workpieces and the heating elements and furnace wall to avoid local shielding that causes uneven temperature; second, control the load per batch during batch loading, because excessively dense loading will obstruct the gas circulation in the furnace and cause temperature differences between the front and rear. Providing the dimensions and placement method of typical workpieces before customization helps determine the appropriate furnace chamber volume.
The temperature control system adopts PID regulation, supports multi-segment programmed heating and cooling, and can achieve temperature control accuracy on the order of ±1°C. In terms of safety, over-temperature alarm, thermocouple break protection, and leakage protection are configured. The over-temperature alarm value is recommended to be set according to the upper process limit and checked regularly. Daily inspection focuses on the connection of thermocouple compensating leads, furnace door sealing, and grounding conditions.
The electrical-to-thermal conversion efficiency of resistance heating is close to 100%, and the overall thermal efficiency of industrial resistance furnaces is usually in the range of 50% to 80%. If the process temperature is below 350°C and liquid-phase circulating heat supply is required, the thermal oil furnace option can be compared separately; for the 950°C operating condition, a resistance furnace is preferable. During selection, weighing process temperature, heat medium type, and operating costs together is closer to actual use than looking only at the quotation.
It is suitable for medium-temperature heating processes such as annealing, tempering, and preheating of metal parts, as well as drying and roasting of chemical materials, and can also be used for laboratory sample processing. For workpieces with high temperature uniformity requirements, it is recommended to explain the loading layout during the customization stage so that the furnace chamber dimensions and power matching can be calculated.
