Apr 02, 2021
Materials For The Shell Of Tubular Heaters
The materials for the shell of the tubular heater are: carbon steel, stainless steel (corrosion resistance), copper (good plasticity and thermal conductivity), titanium, etc. In addition, the heating temperature conditions also have a certain influence on the selection of materials. Generally, the heat-resistant temperature of stainless steel 304 is 600°C. When the heating temperature reaches 800*C, stainless steel 316 needs to be selected.
A strong magnetic beam that changes instantaneously is generated in the coil. When the heated object such as metal is placed in the coil, the magnetic beam will penetrate the entire heated object and interact with the heating power inside the heated object.
Flow in the opposite direction will produce a corresponding large eddy current. Due to the resistance in the heated object, a lot of Joule heat will be generated, which will make the temperature of the object itself rapid.
Rise rapidly. To achieve the purpose of heating all metal materials. Convert electrical energy into thermal energy to heat objects. It is a form of electric energy utilization. Electric heating compared with general fuel heating
High temperature can be obtained (for example, the arc heating temperature can reach more than 3000°C), it is easy to realize automatic temperature control and remote control, and the object to be heated can be kept at the same level as required.
Set temperature distribution.
The temperature of the tubular heater is very high when it is heated, so high-strength and high-heat resistance nickel-chromium-aluminum and iron alloys are used.
In the detection of tubular heaters, the environmental requirements are high, so more rigorous research is needed in the production and selection of materials and processing techniques.
The tubular heater is to put electric heating element in the metal tube and use the lead rod to lead out, and the gap part is tightly filled with crystal oxidation with good heat resistance, thermal conductivity and insulation.
In the heating medium of the tubular heater, different media have different characteristics, such as: water (oxidizing), some chemical media (acid|, alkali corrosive), molten salt (chlorine)
Ionic corrosion), etc., so the selection of materials when making the tubular heater shell has different requirements.
Need to use a voltage of 1800V to conduct a breakdown test to ensure that the resistance wire is uniformly shaped and the heating effect of the tubular heater is guaranteed. After it can be heated, it can be ignored
The problem arises, insulation.
The whole body of the heating tube is basically an electrical conductor. At this time, magnesium oxide with good thermal conductivity and insulation is required to fill the gap between the resistance wire and the shell to achieve the effect of insulation and heat conduction.
In order to ensure the safety of the tubular heater when heating, the insulating porcelain head and 704 high temperature glue are used to seal the end to achieve good insulation (insulation degree ≥ 500MQ).
