The development of modern society has brought opportunities to the production of machinery industry. As an indispensable equipment in the mechanical industry, heat treatment has naturally attracted the attention of the society. Moreover, in the process of using the heat treatment equipment, there will be various failures. Once the maintenance is not timely, it will affect the normal production of the enterprise to a large extent.
The heating body will soften, expand, fall down, lie down and overlap first, and then fuse (melt) after long-term operation. In order to make the furnace wire have a certain strength at high temperature and prevent softening, collapse or sagging, the first thing is to design the structural dimension of the furnace wire, such as the spiral resistance wire, and pay attention to the diameter, pitch and pitch of the alloy element. The heating body shall be installed close to the furnace lining, and the bricks shall be laid flat with expansion space properly reserved. The position of small hook shall be suitable, generally 400-600mm, and it can be firmly hooked to prevent lying down. In addition, in order to prevent the contact between the furnace wires, the isolation piece shall be padded. Can be used 95 porcelain and other high-temperature materials made of sheet insulation resistance wire, to prevent overlapping. In particular, the transition between the brick laying layer and the layer in the furnace (when building the furnace, a gap of 50mm is generally reserved between the brick laying layer and the front and rear end walls, which is used for the turning and installation of the resistance wire), the porcelain plate shall be pre padded, or the furnace wire shall be covered with a porcelain tube (the porcelain tube shall be top to end). The thin slice of diatomite brick saw can not be used to pad in the middle of furnace wire in high temperature furnace. Because diatomite brick has poor heat resistance, it can only be used below 900 ℃, and it is easy to dissolve and deteriorate in high temperature furnace.
For the furnace wire with the trend of lodging, check whether the small hook of the furnace wire plays a role (the hook for erecting the resistance wire belt must be firmly built, pressed and plugged, and shall not be loose), and it can be softened by gas welding or torch baking the furnace wire, and then restore its original shape and size, as well as wear the ceramic tube (the core rod can be worn in the ceramic tube), etc. in the furnace wire. If two porcelain tubes are used at the same time, the end of the porcelain tube must be close to each other.
The heating body can be directly welded to repair the general broken ends. For serious collapse, non straightening and partial over burning, the method of replacing and repairing one section can be adopted. It is not necessary to scrap the whole set because of the partial unqualified parts. It is necessary to note that the material, diameter, pitch and length of the resistance wire used for repair welding shall meet the original technical requirements. The newly repaired resistance wire shall not have cracks, rust, etc Defects shall be even and dense. When using the old resistance wire, there should be no obvious uneven thickness, oxidation corrosion, crack deformation and aging embrittlement. The old lead out rod shall be free from serious oxidation and corrosion.
On 2018-08-08 11:45:46
