Osmelt furnace structure
The electric heating front bed is used to accommodate the final slag containing about 5% lead produced by the Austrian furnace. The final slag flows into the 20×3.162m³ electric heating front bed through the slag chute. The electric heating front bed further precipitates the lead and then sends it to the smoke furnace for processing For the fuming operation of zinc slag, the designed slag height is 1.3m. The precipitated lead is discharged into the lead ladle through the lead discharge port, and is hoisted and transported into the lead pot by the lead ladle. During maintenance, the front bed slag can be quenched and stored by water, and then returned to the smoke furnace. The electric heating front bed uses three graphite electrodes to keep the slag warm, and the power source is drawn from the 10kV power distribution room of the blower room. The control of the base temperature during normal operation is controlled by controlling the electrodes extending into the front bed and the front bed transformer. The three electrodes pass through Three winches located at a height of 9 meters are controlled.
The bottom of the furnace consists of a steel bottom plate supported on the lattice bed. The furnace is designed and installed with allowance for thermal expansion of the furnace steel casing. The bottom is insulated by a layer of refractory material installed on the hearth. Air cooling prevents deformation of the base plate due to continuous heating. Air cooling is produced by natural convection. The open lattice bed facilitates bottom air circulation. Therefore, special attention should be paid to the fact that the bottom should not be covered, sealed or closed.
A refractory lining is used inside the furnace, while the outer shell also needs to be cooled to prevent deformation due to continued heat. This low-intensity cooling method does not have much effect on the heat transfer from the refractory lining, but only cools a thin layer of slag that solidifies the "hot side" of the outer shell and protects the outer steel in the event of refractory failure shell, thus buying time for a safe shutdown. The water-cooled housing design uses a parallel water-cooling loop design, so the water-cooled system can continue to operate after one of the loops fails, allowing safe shutdown under controlled conditions.
The interior of the Ausmelt gun structure consists of four stainless steel concentric sleeves. The fuel (pulverized coal), mixed oxygen air, lance air and sleeve air inside the spray gun will be connected to their respective pipes. The spray gun can be roughly divided into two functional areas: the part above the spray gun mounting plate and the part below the spray gun mounting plate . The part above the mounting plate provides the connection of the process piping, which plays an important role in the lifting and fixing of the spray gun. The lower part of the support plate is a concentric tube that is inserted into the furnace. The total length of the spray gun is 20.86m, and the length of the furnace is less than 12.6m. Among them, the oxygen mixing air duct is the shortest, the spray gun air duct is the longest, the sleeve air duct ends above the cyclone, and the pulverized coal pipe extends below the cyclone.