On 2018-08-08 14:48:54
well furnace structure introduction
The structure of well furnace is: the furnace body is a cylindrical deep well, and the workpiece is vertically loaded into the furnace by a special crane for heating. The fuel used is usually gas and oil. When using electricity as heat source, it is called well resistance furnace. Well furnace is a periodic operation furnace, suitable for heat treatment of rod and long shaft parts. Well furnaces are generally placed in the workshop below the ground plane, there are also placed above the ground plane, or above the ground plane under each half. The name of well furnace has: forced convection well furnace, natural convection well furnace, well gas carburizing furnace and so on.
The cross section of an industrial furnace with a vertical chamber for heat treatment of long rod shaped workpiece is generally round, with a diameter of 0.5 ~ 4.5 meters and a depth of more than 30 meters. Long rod-shaped workpiece, such as gun barrel, turbine spindle, generator rotor, ship spindle and other heavy rod-type workpiece, is placed vertically in the well furnace heating, can avoid bending deformation. The hole of the well furnace is set on the top of the furnace, and the workpiece is suspended vertically in the furnace by special spars. Specialized lifting equipment can be fast
Loading and lifting parts, for the convenience of operation and reduce the height of the workshop, the furnace body is generally installed in the ground or in part. Even so, plants with ultra-deep furnaces still need to be built high. For example, the former electric furnace plant is the well furnace with a diameter of 1.8 meters and a depth of 30 meters, which is 33.5 meters underground. The rail surface height of the bridge crane with 150 tons is up to 36 meters, and the elevation of the lower edge of the plant is up to 42 meters. In conjunction with the well furnace, there shall be quenching cooling tanks and oil tanks of the same depth, as well as blower or spray cooling devices.
When the special workpiece is quenched, the top of the workpiece outside the lifting machine is dipped into the cooling fluid, while the bottom of the workpiece is dipped into the cooling fluid. The workpiece is not evenly heated, which affects the quenching quality. The usual measure is to control the temperature of the upper and lower parts of the furnace to different degrees to compensate. Since the 1920s, the aviation industry has been using a well-type furnace that operates from the bottom of the furnace and is heated by electric heating elements. The bottom of the furnace is built above the ground and can be moved left and right on the ground track. The heated workpiece is moved along with the furnace to the top of the oil tank or water tank, and then the winding machine on the top of the furnace is activated to transfer the workpiece from the furnace through the door at the bottom of the furnace, quickly immersed in the cooling tank to cool. The workpiece from the whole process into the cooling tank and the time in the air are very short, so less oxidation, small temperature drop, lower and lower temperature drop rate is basically the same, can ensure the quenching quality.
Well furnaces can be fueled with gas or liquid fuel, or heated electrically. When using gas fuel, usually have a number of small energy burner, along the tangent direction of the inner wall of the furnace, in the height according to the stratification or a spiral uniform arrangement, to avoid the flame directly scour the workpiece, ensure the furnace temperature uniform. When used for low-temperature tempering or oil-fueled, a thin muffle wall is laid in the furnace to separate the combustion space from the heating space, but a well-type furnace with muffle wall consumes more fuel.
Small well type furnace USES electric heating, most also have special metal muff tank, can carry on the gas carburizing, carburizing, carburizing, bright annealing and other heat treatment. In areas with sufficient power supply, or large well furnaces requiring temperature control are more suitable for electric power.