On 2018-08-08 14:48:54
Effective equipment for well furnace heat treatment
The well furnace is a periodic working furnace, suitable for nantong heat treatment of rod and long shaft parts. The structure of the well furnace is: the furnace body is a cylindrical deep well, the workpiece by the special crane vertically loaded into the furnace heating. The fuels used are usually gas and oil. When electricity is used as the heat source, it is called well resistance furnace. The well type furnace is generally placed in the workshop below the floor plane, also has the placement above the floor plane, or above the floor plane below the half. The name of the well furnace is: forced convection well furnace, natural convection well furnace, well gas carburizing furnace.
The well furnace is one of the main types of boiler in the present mechanical processing. The reason is that this equipment often appears a protective atmosphere in the production, so that the workpiece after the completion of its surface can ensure good accuracy, effectively ensure the workpiece toughness and stiffness.
In the long term, the heating body of the well furnace will become soft, expand, fall down, collapse first and then fuse (melt). The solutions to this problem mainly include:
First, in order to prevent contact between the furnace wire, to pad isolation plate.
Can use 95 porcelain and other high temperature resistant materials made of thin sheet isolation resistance wire, prevent lap. In particular, the furnace between brick layer and layer of the conversion (when building the furnace, brick and front and rear end wall generally leave a 50mm gap between the turning and installation of resistance wire), to advance on the ceramic plate, or furnace wire cover on the porcelain pipe (porcelain pipe to the top of the head). High temperature furnace can not use diatomaceous earth brick saw thin sheet pad in the middle of the furnace wire, because diatomaceous earth brick heat resistance is poor, can only be used in 900℃ below, in the high temperature furnace is easy to dissolve metamorphism.
Second, for the furnace wire to prevent softening, collapse or sag, so that it has a certain degree of strength at high temperature.
First of all, it is necessary to design the structure size of the furnace wire, such as the spiral resistance wire, to pay attention to the alloy element diameter, pitch and spiral diameter. Heating body installation depends on furnace lining, should put flat on putting brick, leave its expansion space appropriately. Small hook position should be appropriate, generally 400 ~ 600mm, and can be firmly hooked to prevent down.
Third, the occurrence of lodging trend of the furnace wire
Check whether the furnace wire hook plays a role (the furnace hook of erasing resistance ribbon must be firmly laid, pressed, plugged and not loosened), and can be made soft by gas welding or blow torch baking stove wire, and then restore its original shape and size, and in the furnace wire wear porcelain tube (porcelain tube can wear mandrel). If two porcelain tubes are used at the same time, the ends of the porcelain tubes must be close together.
Fourth, the heating body fuses
General broken end can be directly welded to repair, for serious collapse, can not be straightening, the local part of the damage is serious, generally can be used to replace a section of the method, not because of the local unqualified on the whole set of scrap.