1. Furnace cover
The furnace cover is composed of an outer ring and an inner ring with an inner diameter of X6.7m and an inner ring with an inner diameter of X2.5m. Refractory fiber is used as insulation material. The furnace cover is powered by a lOt electric hoist, with about 80% of the weight to reduce the lifting force. In order to keep the lifting steady, a guide device is installed in the outer ring of the furnace cover. The practice proves that the lifting device is stable, reliable and accurate in operation. The top of the furnace cover is provided with three ventilation holes, which are used to adjust the cooling speed when cooling.
2. Heating zone
The total heating power of the furnace is 3 276 kW, the outer ring is arranged 1980kW, and the inner ring is arranged 1 296 KW. No resistance elements are arranged on the top and bottom of the furnace. This is because the end area of the cylinder is much smaller than the side area, so the absence of electric heating elements on the top and bottom of the furnace will not affect the temperature uniformity and heating rate of the workpiece.
The furnace cover is divided into 6 layers along the longitudinal, and each layer is divided into 2 zones, so the inner ring and outer ring of the furnace cover are divided into 24 heating zones. The power of the outer ring is 165 kW per zone, and the power of the inner ring is 108 kW per zone. The temperature is controlled by a thermocouple in each zone, so that the dense zone heating and control ensure the temperature uniformity of the furnace and the workpiece. The outer ring was divided into 12 regions, and each divided 2 groups. The inner ring is also divided into 12 zones for temperature control.
3. Stove top
The hearth is the bearing platform for the workpiece and the hearth cover. The well type resistance furnace platform is equipped with four electric self-propelled mechanisms. When the workpiece is loaded and unloaded, the furnace cover is lifted, and the furnace platform can enter and exit by itself, which has the same function as the trolley type furnace car. This is conducive to the loading and unloading of the cylinder, especially when the cylinder is hot and quenched, it can be quickly baked and lifted, and gain valuable time for rapid quenching.
4. Power supply device of furnace cover (contact power supply device)
The contact power supply device is arranged on the furnace cover (no heating element is arranged on the furnace top). The hood is moved up and down, and the hood type furnace adopts two groups of contact power supply devices, which are distributed on the left and right sides of the furnace body. Each group of contact power supply devices contains 36 pairs of electric contact heads, and the receiving end of each pair of electric contact heads is installed on the furnace cover, and the transmitting end is installed on the fixed frame. When supplying power, the electric push rod pushes the transmitting end of the electric contact device to make it closely connected with the receiving end and complete the preparatory work for energizing. When the heating is completed, the electric push rod is moved back, the power supply end of the contact device is moved back, the power supply end is separated from the power supply end, the power supply is completed, the furnace cover is lifted, and the workpiece is released.
5. Furnace cover anti-fall device
The weight of the hood is about 50 t. In order to prevent the accident caused by the accidental fall of the furnace hood at a high level, the anti-fall device is set up. There are two sets of fall prevention devices, which are arranged on both sides of the top of the furnace shelf. When the furnace cover is raised to the highest point, the electric push rod of the fall prevention device will push out the lock rod and enter the fall prevention hole of the furnace cover to prevent falling.