What are the considerations in the structure and use of rapid annealing furnaces?
Rapid annealing furnace generally uses tungsten iodide lamp tube as heating element, heating speed is fast. Temperature measurement and fuzzy PID control using S-type thermocouple, high precision temperature control <5. The rapid annealing furnace is equipped with a vacuum device and can work in various atmospheres. Greatly improve its application range. Standard accessories: 1 pair of high temperature gloves, 1 thermocouple, 1 quartz tube, 1 set of vacuum flange. Optional: alumina crucible, time crucible, vacuum pump.
The rapid annealing furnace is mainly composed of furnace body, furnace lining, furnace cover, vacuum pumping device and temperature control system.
The shell of the furnace is made of welded steel and steel plates, and the furnace is constructed of aluminum silicate refractory fiber modules and ultra-light high-aluminum foam bricks.
The corrugated heating element is fixed to the lining cotton by means of high aluminum porcelain nails.
There is a furnace bladder made of heat-resistant plate in the furnace, and the workpiece to be treated is placed in the furnace bladder.
The furnace cover is equipped with a ventilator to force air circulation, so that the temperature and gas in the furnace are uniform.
The furnace cover is sealed with the furnace gallbladder flange, and the furnace cover is connected with the vacuum device.
The temperature control system adopts PID programmable control, which has the function of overtemperature alarm and fault self-diagnosis.
Quick annealing furnace use precautions:
1. After the furnace is used or not used for a long time, bake for 1 hour around 120 and 2 hours around 300 to avoid cracking of the furnace. Try not to exceed the rated temperature, so as not to damage the heating elements and lining. It is strictly prohibited to pour all kinds of liquids and dissolved metals directly into the furnace to keep the furnace clean.
(2) If the quartz tube is used in the furnace, when the temperature is higher than 1000, the high-temperature part of the quartz tube will be opaque, which is called permeability (also called crystallization), which is an inherent defect of continuous melting of the quartz tube, which is a normal phenomenon.
3. When using a cold furnace, because the furnace is cold, it needs a lot of heat absorption, so the temperature rise rate of the low temperature section is not easy to be too fast, and the temperature rise of each temperature section
The temperature difference is not too large, and the physical and chemical properties of the sintered material should be fully considered when setting the heating rate to avoid the phenomenon of spraying and polluting the furnace tube.
4. Regularly check whether the electrical connection parts of the temperature control system are in good contact, and pay special attention to whether the connection points of the heating elements are tight.
5. After the furnace is used for a period of time, if the vacuum degree decreases, the heat-resistant silicone ring between the stainless steel flanges should be replaced or the stainless steel flanges should be re-installed or the vacuum system should be replaced and repaired to improve the overall vacuum degree of the system.
6. In the working process of the furnace, generally around 300, if the control deviation cannot be eliminated, the temperature display value does not match the given value in the program or the fluctuation is too large, check whether the parameters "M5, P, T" are set correctly.