Resistance furnace maintenance and repair

Electric body damage for the following reasons: mechanical force damage.
In the manufacture and repair of electric furnace, sometimes to his wound resistance wire, during processing, do not damage the surface, such as scratches or other injuries jaw folder. In addition, non-ferrous metal production winding jig can not be used, because the non-ferrous metal alloy particles tend to stick on the wire surface, the alloy wire is wound easily broken, reduced service life. After winding of the spiral body to eliminate the adhesion of dirt should be clean.
Furnace loading products should be avoided and electric body collision, especially iron-chromium-aluminum, the repeated use of brittle grain growth, the higher the temperature, the longer, the more severe embrittlement after cooling. Therefore, the high temperature of the iron-chromium-aluminum components used in the cooling, do not stretch, bend and impact.
Silicon carbide and silicon molybdenum rod texture is very crisp, the installation process should not touch off.
Demolition, the first clamp and plate for unloading, carefully remove the tube and silicon carbide ceramic refractory fibers between, out of the damaged components, and observed the upper and lower (or left and right) of the ceramic tube centerline of whether a re-synthesis line. And then install the new silicon carbide.

Furnace (car bottom furnace) Introduction and safety technical regulations

Car Bottom Furnace Products:
For weight of more than ten tons to hundreds of tons of ingot heating before forging, furnace room or tunnel-type. Heated objects placed in the trolley, furnace loading and unloading by the workshop crane or other traction devices trolley pulled into or out of the furnace, the large ingot heating requirements furnace temperature evenly distributed, car bottom furnace is often a distributed heating burner and smoke crossing dispersion and dispersion of smoke (arranged on the side wall of the furnace).
Technical specification for safety:
1, safe, all furnace must have the following components and safety facilities. The outlet temperature of the automatic adjusting means; the feedstock oil automatic control means; furnace, convection, furnace tubes, radiation, temperature indication of the flue;
Population and superheated steam pressure gauge furnace; damper and flue baffle; emergency venting devices; blast doors; hearth and back elbow tank fire steam line.
3. The new furnace according to prescribed procedures must be put into use, the heating curve Ovens.
4. Furnace ignition off good hole, the flue baffle opening to 1/3 1/2, fuel oil systems circulation and circulation of raw materials, ready to soak diesel ignition stick.
5. Ignition steam furnace residue gas rush the net, on the upper end of the burner will ignite ignition rods, others to leave the bottom of the furnace, steam slightly open, and then open the oil line. Point fuel fire, regulate oil and gas than to a normal state.
6. Cited gas off the net water storage and condensed oil and drained in a safe place for more than 15 minutes, the laboratory analysis of the oxygen content of less than 1%, before the vote with the ignition. Gas into the blast furnace must pass the flame arrester.
7. Ignition fireman can not face the fire mouth and see the fire window to avoid tempering wounding. If the flame goes out, the fuel valve should be closed immediately, the furnace domestic demand steam purge in order to re-ignition.
8. Normal operation should always check the stove burning at any time to adjust, pay attention to check whether the tube bending, bubbling, peeling, redness and dark abnormal situation, pay attention to check back elbow, plug, entrances valve flange seamless oil phenomenon, abnormal, and immediately reported to the leadership, to take measures to deal with.
Case of burn-through caused by a ruptured tube furnace of fire or an emergency need into the furnace, the application of steam to put out the fire cooling treatment, no water is injected into the furnace for fire fighting and cooling.
10 into the furnace overhaul should handle into the equipment and operating procedures. Explosion-proof doors shall not be blocked with other objects, so as not to lose the explosion-proof effect.
11. Furnace heating or shutdown cooling must be strictly in accordance with the provisions of the heating and cooling rate.
12 emergency shutdown, against only wind instrument used to close the control valve, be sure to close the blast furnace hand valve.
(13) In case of the heating medium interrupts should immediately fire the furnace pass into the steam.

Air-cooled vacuum sintering furnace

Air-cooled vacuum sintering furnace is introduced:
Air-cooled vacuum sintering furnace, by using the method of resistance heating can be achieved for rare earth permanent magnet sintering, purification of hydrogen storage material, electrical alloy bright annealing, brazing material such as stainless steel, precision alloy, tools, measuring and cutting, heat treatment. This equipment has high degree of vacuum, forced inside and outside air cooling circulation, cooling speed, mean temperature sex good, high automatic degree, etc.
Air-cooled vacuum sintering furnace use:
Cooled vacuum sintering furnace is a vacuum resistance is a new generation of vacuum heat treatment equipment. He has a high degree of vacuum, forced air cooling speed, high efficiency, good temperature, high degree of automation, etc. Legal system is mainly used for dry powder of vacuum sintering magnetic materials, hydrogen storage material of homogeneous purification and tools, precision alloy heat treatment, etc.
Air-cooled vacuum sintering furnace structure:
Air-cooled vacuum sintering furnace is horizontal structure, consists of furnace body, heating chamber, vacuum system, air cooled heat exchanger system, water cooling system, pneumatic system and electric control system components. Furnace for water-cooled wall structure, loading and temperature measuring thermocouple, etc. Heating chamber of the heating body made of molybdenum sheet, and selects the advanced thermal insulation material of incubator, heating process for the three sections of temperature control, can improve the temperature uniformity. Air-cooled heat exchanger by outer circulating system, after heated gas through a heat exchanger, blower driven, and back hot spray to the work, make its rapid cooling. Control system mainly consists of two parts, electric control cabinet and magnetic voltage regulator. Temperature is controlled by microprocessor program temperature recorder PC programmable controller and configuration actions of institutions, such as process control. Vacuum system adopts large pumping speed and dust catcher of high vacuum diffusion unit pump, diffusion pump, roots pump, vane pump.

Muffle furnace heating element

The heating element is an important member of the resistance furnace is a resistance furnace heat sources. Understand the performance, structure and characteristics of the heating element material, it is very important for the correct use of the resistance furnace.
Surface load of the heating element and the shape
Surface load of the heating element
When the current through the heating element, due to the role of the resistance of the heating element, the electrical energy into heat energy conversion law in line with Joule's law. Heating element electrical energy into thermal energy by heat conduction, convection and radiation distributed to the furnace, the ability to disseminate the surface load. The surface load of the heating element is defined as the power per unit area on the surface of the component can be distributed W/cm2. The larger the surface load of the heating element, the more heat comes out of the heating element itself, the higher the temperature. Consider increasing the element surface of the load may be correspondingly reduced surface area of ??the heating element, reducing the amount of heating elements, but is not conducive to the lifetime of the elements from the heating power of the resistance furnace. Conversely, reduced element of the surface load can be a corresponding increase in the surface area of ??the element, and is conducive to the lifetime of the elements, but increased the amount of the heating elements. In addition to the cooling effect of the surface load on the heating element, its shape also have a certain impact, in general, the ribbon components than the linear thermal conditions, the surface load.
Common shape of the heating element
The shape of the heating element depending on its material and installation, linear, spiral, mesh, ribbon and the rod-shaped structure, wherein the metal heating element is generally linear, spiral, a mesh or a ribbon, as opposed to metal heating element is generally rod. Linear heating elements in the oven cavity made of metal wire around certain requirements from the system; spiral heating element is wound into a spiral wire first and then install the oven cavity; mesh heating element wire braid and into; ribbon heating elements are made of metal directly processed into.

Optimization atmosphere furnace cooling rate

Traditional depends mainly on the furnace atmosphere furnace cooling water circulation inside the sandwich away part of the heat, the cooling speed is relatively slow. Sometimes up to 36h or so to cool to about 150 ℃.
The high-performance cores require rapid cooling, the design presented in the following optimization program:
(1) Cycle Air Act: cooling the charge into the furnace through the nitrogen to pour out of the tower, and then into the furnace, recycled. Meanwhile, in order to prevent leakage, to continue to add part of the nitrogen gas into the furnace to ensure the nitrogen partial pressure in the furnace.
(2) Box bottom openings, and the cold side of the silicon molybdenum rod gap forming gas convection, take away box furnace heat;
(3) The box-type furnace purged with nitrogen, the heat away sintered product;
(4) accelerate the rate of water flow within the furnace sandwich. These types of programs can be used simultaneously, the cooling time can be shortened to about 15h.

The range of application of the high-temperature furnace

High-temperature furnace is the national standard energy-saving cycle operating furnace, mainly for steel products, a variety of metal parts normalizing, hardening, annealing heat treatment purposes, or diamond cutting blade for high-temperature sintering purposes.
High-temperature furnace Precautions
In addition to doing the experiment, do not stay in the area of ??high-temperature furnace tube.
Experimental work is completed, if not continue to use special gas, close reserved N2 flow tube maintained at the standby temperature and see if there are other power the customs not related, such as: cleanhood light, boiling acid with a small electric furnace or other, please turn off.
Dealing with HF, gloves, such as accidentally ran into HF, immediately flush with calcium gluconate plus 2% water, rub the wound 15 '.
Quartz glass products be used with care, so as not to rupture, causing severe cuts.
Avoid inhalation of smoke from the stove or treatment tank of gas.
Potassium cyanide (KCN) can not be set, because the two can produce highly toxic KCN gas mixed with acids.
Once found to interfere with the security of things, please immediately notify the relevant personnel (technicians).
Please save the amount of pure water.
Broken wafer, filter paper, cotton swabs ....... Do not fall into the drainage holes at the bottom of the cleaning tank, so as not to cause the floor to waterlogging due to poor drainage.
Length of putting the front end, not to facing up to avoid contamination.
Wafer into the baked mouth, to undertake the holder of the boat, do not touch the tube mouth, to avoid contamination of the furnace tube.

Furnace charging into the furnace and power transmission

First, the charge into the furnace:
Charge into the blast furnace, electric furnace steelmaking operations plan should be based on the ingredients in a single audit charge weight and alloy elements and ingredients and feed weight pad in the bottom 1 to 2% of lime.
Top loading baskets have someone directing, opened the lid, it should promptly baskets hanging into the center of the furnace may not be too high, too biased and too low. In baskets of chain plate is not bad as far as sticky lower. For the second feeding, not other primary materials entirely of clear before feeding, to avoid spraying and splashing of molten steel, but also to prevent the explosion, humid charge non-loading of the material into several baskets.
After charging into the furnace, for excessive burden should flatten or hanging out, so as not to affect the fastening lid while preventing the lid was arcing and leakage.
Second, the power transmission:
Charge into the furnace after the power transmission before the deal lid, electrodes, cooling system, mechanical transmission, electrical equipment, etc. for inspection, if found to be timely treatment failure, resulting in the smelting process in order to avoid downtime; also check the charge with the door or cooling system is touching, if exposed to immediately exclude, in order to avoid transmission after breakdown.
If the electrode is not long enough, it is best replaced before the transmission, such as loose fitting location, should be tightened in order to facilitate a Chuanjing success, reducing downtime caused by the phenomenon of the smelting process.