English 
Русский 
Aluminum alloy induction furnace is a non-standard induction heating equipment specially designed for aluminum alloy heating forging and hot extrusion. It heats aluminum rods and aluminum plates through the principle of electromagnetic induction heating.
Since alloy aluminum is a non-magnetic material, special treatment needs to be taken when designing the inductor of aluminum alloy intermediate frequency furnace to ensure that the induction heating of aluminum alloy intermediate frequency furnace meets the process requirements.
Here, the editor of Haishan Electric Furnace will introduce the parameter selection of the sensor of the aluminum alloy intermediate frequency furnace.
Determination of the furnace lining of the aluminum alloy intermediate frequency furnace
The heating temperature of the aluminum alloy billet is generally less than 500°C. The induction lining of the aluminum alloy induction furnace does not need to be made of high temperature resistant refractory materials, and is generally rolled with austenitic stainless steel (such as 1Cr18Ni9Ti, etc.).
The wall thickness of the stainless steel furnace lining is 2-3mm, and there is a gap of 15-20mm when rolling, and a pad made of refractory material is clamped along the gap. Considering that the stainless steel lining expands toward the feed end after being heated, only the discharge end of the furnace lining is fixed.
The outer surface of the induction stainless steel lining of the aluminum alloy intermediate frequency furnace is wrapped with a 1mm thick silicone mica plate and a 5mm thick high alumina aluminum silicate fiber.
In this way, the thickness of the furnace lining can be controlled within 10mm, and the ratio of the coil diameter to the furnace lining diameter is small, so that the electrical efficiency and power factor of the inductor are greatly improved.
For general aluminum alloy inductors, the ratio of the coil diameter to the furnace lining diameter is 1.3 to 1.5.
The guide rail of the sensor of the aluminum alloy intermediate frequency furnace
The guide rail of the inductor of the aluminum alloy intermediate frequency furnace is a 90° arc-shaped guide plate made of austenitic stainless steel plate with a thickness of 2 to 3 mm.
The guide plate usually adopts two sections of different lengths: the short section is fastened to the end plate at the feed end, and the long section of the guide plate fastened to the discharge end is pressed down.
The length of the sensor of the aluminum alloy intermediate frequency furnace:
The influence of the end effect should be considered when designing the aluminum alloy step heating inductor, and the added supplementary length is expressed by Δa.
To adjust the position of the limit switch of the pushing machine, adjust the distance of the discharge end Δa of the sensor to (0.5~1) D1.
If Δa is too small, the temperature at the end will drop, and if Δa is too large, high-temperature oxidation will occur at the end of the aluminum alloy and the surface will blister.
The length of the aluminum alloy sensor should be reasonably designed.
Because their forging temperature is very close to the critical temperature, the length of the inductor cannot be designed too long. An excessively long inductor may cause the billet temperature to overheat regardless of continuous heating or step heating.