radiating tube / electric heating radiant tube

The inner core of the radiating tube is composed of a resistance wire welded at the end of the U-shaped axial arrangement and a ceramic support frame. There is no shielding between the inner core and the outer protective sleeve, and the heat dissipation is good. The electric heating radiant tube with rated working temperature of 1000 degrees, the material of the resistance wire is Cr20Ni80 or 0Cr21Al6Nb, the surface working temperature can reach 1200 degrees, the maximum working temperature of the electric heating radiant tube with this material can reach 1000 degrees, and the support frame is high aluminum ceramic parts. The outer protective sleeve is a cold drawn seamless thin-walled heat-resistant steel pipe, and the material is 1Cr25Ni20Si2 or 1Cr25Ni35Si2. The material has good high-temperature oxidation resistance, high-temperature creep strength, and has a certain resistance to carburization. The radiation tube design and material selection safety factor Larger.
The electric heating radiant tube with rated working temperature of 1200 degrees, the material of the resistance wire is 0Cr27Al7Mo2, and the surface working temperature can reach 1400 degrees. The maximum working temperature of the electric heating radiant tube with this material in a short time is 1250 degrees. The outer protective sleeve is a cold-drawn seamless thin-wall heat-resistant steel pipe, the material is Fe-Ni-Cr-Al-Re alloy, the material has ultra-high oxidation resistance, long-term work in an oxidizing atmosphere at 1300 degrees, short-term resistance at 1360 degrees Oxidation. Applicable to work in high temperature and low oxygen partial pressure and S, C environment.

In addition to supporting the domestic heat treatment equipment manufacturers, the electric radiation tubes developed and produced by our factory can also be used to research and design and manufacture non-standard product heaters for users. According to the conditions of use, they can be divided into: heat-resistant steel seamless tubes and sheet rings Welded pipes, centrifugally cast pipes and non-metallic sleeves, etc.

electric heating radiant tube
Characteristics of high temperature electric heating radiant tube:
1. Manufacture of seamless cold-drawn heat-resistant steel pipes (maximum temperature is 1200 degrees) produced with high-quality raw materials
2. The inner core adopts the resistance wire U-shaped axially arranged end welding method
3. The resistance wire and the ceramic frame are basically unshielded, and the temperature difference between the resistance wire and the furnace chamber is small
4. The maximum working temperature is 1000 degrees or 1200 degrees
5. The biggest advantage of the radiant tube produced by our company is the use of seamless cold-drawn, thin-walled heat-resistant steel pipe (1Cr25Ni20Si2 or 0Cr25Ni20Si2). The thermal radiation of its products is 10% higher than similar products
6. Use more than 8000h

radiating tube

In the production process, our factory strictly controls the following

(1) Electric heating materials
The heating wire is required to have a high degree of heat resistance; the material has no impurities, no segregation, and strong oxidation resistance; during use, it does not deform, puncture, and has no leaks.

shop sign Cr Ni AL Mn P S C Fe
Cr20Ni80 20~23 margin ≤0.5 ≤0.6 ≤0.02 ≤0.02 ≤0.08 ≤1.0
0Cr25AL5 23~26 ≤0.06 4~7 ≤0.07 ≤0.02 ≤0.02 ≤0.06 margin
0Cr21AL6Nb 21~23 ≤0.06 5~7 ≤0.07 ≤0.02 ≤0.02 ≤0.05 margin
0Cr27AL7Mo2 26~28 ≤0.06 5~7 ≤0.02 ≤0.02 ≤0.02 ≤0.05 margin

(2) Refractories off
The refractory material is required to be corundum. During the operation of the radiant tube, it has high high-temperature strength and high-temperature insulation capacity, without cracking or leakage

performance index
Refractoriness ℃ 1650
Bulk density g / cm3 2.8-3.0
Apparent porosity/% 15-18
Thermal expansion /% 0.6-0.8
Thermal shock stability ℃ / water cooling 80

Radiant Tube

(3) Protection cover
The OCr25Ni20Si2 cover adopted by our factory has little deformation when the tube is locally heated, and it has no effect on the heating element and the working environment in the furnace. It has strong heat resistance and the normal use time is 6000 ~ 10000 hours, which is the domestic leading level.

Steel number C Si Mn P S Cr Ni
1Cr25Ni20Si2 1.5-2.5 ≤1.5 ≤0.03 ≤0.03 ≥24.0 ≥18.4

(4) Production process
During the straightening of the heating wire, there is no crack; during the welding process, the welding meat is full and smooth, without overheating segregation and virtual welding.
After a large number of customers use it, it has been confirmed that under normal operating temperature and load, the electric heating radiant tube produced by our factory is used in a variety of furnace bodies, and the use time is more than 8000 hours. The factory welcomes people from all walks of life to visit and guide, and is willing to discuss with colleagues in the industry and make progress together.

Radiation tube has the following advantages

(1) It can guarantee the controllability of the atmosphere in the furnace;
(2) Temperature control, installation and maintenance are more convenient and easy to seal;
(3) Since there is no muffle pot in the furnace, the furnace volume is enlarged and the production capacity is improved;
(4) Strong heating capacity and high efficiency;

(5) Saving heat-resistant steel.

Product use and maintenance

(1) Prohibit the use of excessive temperature and overload for a long time;
(2) When the furnace temperature is 400 ℃, rapid cooling is not allowed;
(3) Do not touch the radiant tube when loading and discharging;
(4) When the furnace is working, always pay attention to whether the traffic lights on the control panel are normal, and the traffic lights must be exchanged once after a period of time to keep the radiation tube burned due to the failure of the control switch;
(5) Pay attention to the working condition of the instrument at any time, and must analyze and process it in time when the furnace temperature and instrument indication are abnormal;
(6) For furnaces with a capacity of more than 100KW, it is better to install an ammeter for inspection in each heating zone. An ammeter should be installed for each phase of the three-chamber high-temperature electric furnace.

Second, maintenance
(1) After three to four months of use, draw out the radiant tube, pour out the dust in the radiant tube, turn the radiant tube 180 ° and use it;
(2) Pay attention to indicate the positive and negative poles of the radiant tube, and exchange the positive and negative poles once every three to four months;
(3) After pulling out the radiant tube, be careful when disassembling the binding posts, and do not hit or knock the lead rod;
(4) The bolts leading out of the terminal clamp are prone to oxidative loosening and should be checked and tightened regularly.

Common process elimination methods

Serial number Fault phenomenon cause Method of exclusion
1 Component short circuit 1. The resistance wire is in contact with the steel pipe 1. The resistance wire should be annealed and wound tightly
2. Improper transition of the resistance wire between the 2 core tubes 2. Adopt a reasonable transition method
3. The heat-resistant core tube or porcelain plate is broken 3. Choose the material and be careful not to break it
4. Too much oxide scale dropped at the bottom of the tube 4. Place refractory bricks at the bottom of the tube
5. Within the scope of material size control
2 Broken core tube or porcelain tube 1. The quality of heat-resistant porcelain is not good 1. Pay attention to the quality of porcelain
2. Flame contact with porcelain during gas welding 2. Avoid flame contact with porcelain
3. Violent collision or vibration during installation 3. Avoid collision and vibration
4. Excessive heating during use 4. Choose materials and improve structure
3 Radiation tube cracking 1. Bad welding materials 1. Welding materials are selected
2. Improper welding operation 2. Welding according to specifications
4 Radiation tube deformation 1. The material of the radiant tube is not good 1. Choose the right materials
2. Improper lifting or thermal stress deformation 2. Hang it correctly, and take measures in time if it is deformed
3. Horizontal placement, improper force 3. When placed horizontally, there should be a support frame

1. The user should provide product drawings or samples. If there are no drawings or samples, the product specifications, models, voltage, power, length, diameter and other information must be provided;
2. According to customer needs, we can provide customers with design solutions.

 

Eternal Bliss Alloy Casting & Forging Co, Ltd.

Technical Dept.

E-mail: sales@ebcastworld.com

what’s app:+0086-1826 6227 4295

Caesar

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