Design of tubular heater and blackening of magnesium powder
The electric tubular heater uses MgO powder as the filler. This is a familiar method. However, after the electric heating element is used, the electrical performance is quickly deteriorated, the high voltage, the insulation is reduced, the leakage is increased, and the metal sheath tube is severely broken. When we dissected this electric heating tubular, we found that M four powder has changed from white or light yellow to gray or black. Moreover, no matter which powder is used, including imported powder, it may turn black. Therefore, it is a concern of all manufacturers and researchers to find the cause of blackening of magnesium powder and take corresponding preventive measures. In this paper, the relationship between the design of electric heating tubes and the blackening of magnesium powder is discussed in terms of technology. work. Control method of magnesium oxide powder production enterprise
There are dozens of domestic magnesium powder production enterprises. Due to the different raw materials procurement, different production processes, different processing equipment, and different quality assurance systems, the quality of magnesium powder produced is not the same. Due to the market competition, the production companies have kept the iron powder production technology confidential and learned that the iron drum is general, which affects the morning and effective quality control of the magnesium powder production technology to a certain extent; on the other hand, these "iron "Barrel" is an open secret, but it is only the "ostrich policy" that it has implemented, which is not conducive to the development of the industry and the improvement of its technical level.
A household appliance heat pipe manufacturer (Party A) ordered 20 tons of low-temperature modified magnesium powder from a magnesium powder production enterprise (Party B) and proposed to work according to the SQgo02 standard. Party B must go to Party A for on-site inspection and approval, but Party B lost it for confidentiality. This order, of course, is not clear if there are other reasons.
1 Raw material production should be stable
The raw material for the production of magnesium oxide powder is magnesite, which contains about 47.6 % of MgO. There are a large number of magnesite ore bases in the Liaodong Peninsula of China, but the ore content varies from region to region. Example: Fengcheng's hydrous ore, because crystallization can not be excluded in smelting, therefore, affects the quality of fused crystalline magnesium oxide; and the fused crystal magnesia produced by Payan Biling Mine is distinct in color and white, bright and shining , the raw materials for making electric heating pipes.
Some units have insufficient understanding of magnesite. Regardless of the three or seventy-one, as long as it is a fused crystal magnesium oxide block, it is cheap to buy, and it is not strictly screened at home, ground into powder, and then mixed with silicone resin. Declaring the end of production, the electric heating tube made of this powder is more prone to quality problems.
We have experimented and found magnesium powder from different places. Using the same modification process, the performance of magnesium powder is quite different, and some coating, water immersion, moist heat, and flow rate are very good, and some are not, which fully demonstrates the importance of stable production of raw materials.