Heat treatment furnace energy requirements

For an energy-efficient furnace basic requirements are: a larger bottom (or furnace) effective use of space (or hearth rate), in this area (or furnace) has a uniform temperature field, a higher loading capacity ; furnace heating element (or device), the furnace gas, the furnace of the workpiece has a good heat transfer, the heating time can be shortened work; good thermal insulation and less heat loss, a higher thermal efficiency. These requirements depend on the rational design of the furnace, lining, heating element (or device) or the like.
Lining.
Furnace lining to ensure structural strength and heat resistance of the premise, it should enhance thermal insulation capacity and feed savings. Simply increasing the thickness of the lining to reduce the temperature of the furnace wall is not appropriate, because it will not only increase the cost of heat and lining savings, but also a corresponding reduction in the bottom area (or chamber) for effective utilization. Achieve lining fibrosis and lightweight, has a great energy saving effect.
Refractory fiber lining can be used with prefabricated blocks laid up or installation, can also be refractory fiber spraying. An annealing furnace refractory fiber coating on the lining, and achieved good energy saving effect, light brick lining energy than a 40% reduction.
Heating element heating element arranged arrangement has some influence on the energy, which evenly arranged in the furnace temperature uniformity can be formed effective treatment space. Heating elements installed in the door, you can improve the phenomenon of low temperature blast furnace area, and sometimes not to set the furnace mouth channel, expanding the use of blast furnace zone area. Using radiant tube heating elements conducive temperature uniformity and energy.
Furnace structure and enhance the heat exchange chamber to form a heat exchange system, the heating elements, the lining, the heat exchange between the three parts. Improve furnace exchange often the following measures:
Reasonable furnace space on the TLC (single piece) fabric stove, furnace should be flat at the top of the furnace, furnace heating elements are arranged below the floor, reaching up and down both sides of the uniform heating.
Pit furnace without increasing the space under the premise of increasing the area of ??the furnace wall, to increase the heat exchange area, such as the use of corrugated roof.
Using a circular furnace, box furnace replacement, can enhance the uniformity of furnace heat transfer effect on the workpiece, and reduce the amount of heat the furnace wall.
Inner lining of high emissivity coating paint.
Install the furnace fan to enhance the convective heat furnace gas. Especially chemical heat treatment furnace, high-speed airflow can damage the surface of the workpiece hinder stagnation heat transfer and interfacial reaction furnace gas boundary bottom, played shorten the heating time and speed the process of chemical heat treatment effect.
Seal chamber, including the lead member of the furnace, the furnace shell, etc. of the sealing door. Sealing effect controlled atmosphere furnace, the workpiece quality and energy consumption. When the furnace has 96Pa negative pressure through the holes will be sucked into 3cm2 10m3 / h of cold air, the door opened 0.2m2, energy consumption will increase by 15%.
Deep furnace should also pay attention to the furnace shell sealed, deep like a furnace chimney when the furnace bottom Mifengbuyan, it will cause cracks in the lower part of the cold air from the suction chamber, the hot air from the upper overflow, causing the furnace area under the temperature is low, slow warming phenomenon.
In the erection of strong radiation resistance furnace components, this structure improves the radiation area of the inner wall of the furnace, but also improves the radiation rate.

Box furnace furnace

1 open in front of the stove to prepare
(1) Check the electrical control box for tools or other conductive material, the furnace if forgotten workpiece should be promptly removed.
(2) Check the electrical switch contact is normal after closing.
(3) Check the temperature control instrumentation work properly, and open the switch, so that it is in working condition.
Open furnace production:
(1) automatic temperature control instrument according to process requirements will be a good temperature.
(2) the control handle on the automatic control of temperature location.
(3) cold oven to heat up to the temperature for 2h can be loaded into the workpiece, continuous production, allowing continuous furnace installed.
(4) parts should be placed in the furnace uniform, smooth, parts and electric wire contact is not allowed.
(5) operate in strict accordance with technical rules.

The refractory should meet requirements

Refractory lining, whether it is used for induction channel furnace, or coreless induction furnace, should meet the following requirements.
(1) good chemical stability;
Aluminum and aluminum alloys not only high chemical activity, but also excellent melt fluidity. The viscosity of the molten aluminum at 750 ° C when only 1.04 centipoise, fairly close to 20 ° C when the viscosity of water (1.0 centipoise), which is its easy penetration and chemical reactions occur mainly due to the inside of the lining. The temperature of liquid aluminum in contact with refractories, aluminum strong reducing effect. Refractory SiO2, TiO2, FeO oxide to aluminum reduction. Liquid aluminum and the reaction between the refractory lining is not only affected the quality of the product, and the lining surface nodulation, drum kits and precipitation debris, impregnated portion of the liquid aluminum and the original brick interface cracks shutdown also cause spalling. Therefore, contact with liquid aluminum lining material, you must have a high chemical stability and the least possible amount of impregnation.
(2) have a good erosion resistance;
Usually, in order to make the furnace has a higher electrical efficiency, the thin design of the furnace wall material, but the furnace during operation, due to the electromagnetic force, the molten metal in the furnace kept somersault and stirred continuous erosion and wear lining . Induction channel furnace, with a jet-type melt channel, erosion and wear of the melt channel refractories are more serious. Therefore, the requirements of the refractory material used must have a high mechanical strength and hardness.
(3) have a higher density and volume stability;
As a smelting furnace refractories in the case of certain materials, are hoped to obtain a higher density and volume stability. Bulk density level, and the reaction of the internal porosity of the molded body content, in particular the degree of sintering is good or bad. The higher the stability of the volume of material, the possibility of cracks during sintering and use the smaller, the smaller the width of the cracks, the stronger the resistance to penetration ability.
(4) not easy to produce furnace tumor;
Furnace tumors rarely possible due to the surface of the melt, the presence of impurities or internal (for example, Al2O3) is formed. A significant reduction in the furnace tumor causes the furnace capacity, and metal tumor itself dense, tough, it is very difficult to get rid of.
(5) can not easily be wetting and penetration of the liquid metal;
As well known, the refractory material is a brittle material, inevitable cracks in the heating and cooling process. But one of the key factors that determine their life is the size of the crack and the crack propagation rate. Crack propagation with liquid metal wetting and penetration ability of the contact materials. Wetting ability is worse, the more favorable.
(6) good resistance to thermal shock performance;
This is a coreless induction furnace is especially important. Because no furnace practices feeding - Melting - baked "process cycle, the lining material is subjected to repeated thermal shock. Refractory thermal shock resistance is poor, you can easily cracks and crack propagation, the liquid metal penetration in the short term to the coil at the entire lining scrapped.

Continuous-Lvbang heating furnace

The continuous Lvbang furnace:
The continuous aluminum rod furnace majority for heating before rolling metal blanks, a few for forging and heat treatment. The preform in the furnace according to the rhythm of the rolling continuously moving continuous flow of the furnace gas in the furnace; Usually, in the case of the sectional size of the charge, variety and constant production, the temperature of the portion of the furnace and the furnace metal material the temperature does not substantially change over time and only along the length of the furnace changes.
Continuous aluminum bar furnace advantages:
A continuous Lvbang furnace usually used of the fuel gas, heavy oil, or pulverized coal, some lump coal burning. In order to effectively utilize the exhaust heat, preheated air and installed in the flue gas heat exchanger, or install a waste heat boiler. In the production of forging and rolling, the billet Usually heating in an oxidizing atmosphere in the complete combustion flame. Directly heating the metal, can achieve the purpose of the non-oxidizing or less oxidized reducing incomplete combustion flame (i.e. "self protective atmosphere). This heating method is called open fire or open flame oxidation heating, successfully applied to the rotary hearth furnace and chamber furnace.

The structure of industrial furnaces

Industrial furnace heating the material to physical and chemical changes in industrial heating equipment. Furnace and kiln and distinguishable, but a slightly different meaning. In the machinery industry, generally used to complete workpiece or material thermal heating, melting and heat treatment process used thermal equipment called a furnace, and for silicate industrial heating equipment called a kiln. The industrial furnaces often referred to as industrial furnaces.
With the needs of the different production processes, the structure of industrial furnaces in many forms, but in general, shall meet the following requirements:
1) heating speed, high yield per unit area.
2) furnace temperature, the atmosphere is easy to control the product quality is good.
3) in the low energy consumption, high thermal efficiency.
4) The structure is simple, low cost, long life, easy maintenance.
5) operation is simple, a higher degree of mechanization and automation, less environmental pollution, good working conditions.

Introduction of crucible furnace

Crucible furnace
For laboratory, industrial and mining enterprises, scientific research units for elemental analysis determination of melting metal and small pieces of steel heat treatment heating.
The crucible furnace shell are cylinder. Furnace shell of welded Pu steel. Studio one by refractory fired into the the overall furnace, furnace wear silk tank, the heating element placed on the wear silk tank. Between the furnace and the furnace shell with fan foam brick, vermiculite insulation. The electric furnace with temperature control, furnace temperature can be measured with thermocouples.
Crucible furnace Features:
1, using intelligent instrument temperature control, high precision temperature control.
2, the furnace wire wound around the furnace liner is reasonably arranged, temperature uniformity.
3, can be customized according to customer needs non-standard models.
Crucible furnace applications:
Crucible furnace is used for various industrial and mining enterprises, universities, research institutes for elemental analysis, small pieces of steel hardening, annealing, tempering heating. The carbon heater dedicated to steel mills, iron foundries, laboratories for carbon and sulfur analysis. All high-temperature furnace with temperature controller, with the thermocouple temperature indicating controller, automatic control of temperature in the furnace. Analog and digital temperature control instrument is divided into two kinds. The other can be customized all kinds of special specifications large box-type furnace, tube furnace, tempering furnace pit.

Laboratory muffle furnace Features

Furnace intelligent controller integrated design, beautiful, generous, door side door design.
Laboratory muffle furnace using both sides of the liner heating elements, easy to replace the furnace wire, made of imported ultra-high temperature heating element, more excellent oxidation resistance, greatly increasing the service life.
Laboratory muffle furnace with ceramic fiber insulation, greatly improved the heating rate and reduces energy consumption compared with traditional muffle furnace weight 1/2, the heating rate increased by 1, and significant savings in energy , life expectancy increased by 3.5 times; effective insulation, furnace surface temperature is low.
Laboratory muffle furnace with a new digital display, digital set temperature, intelligent control technology, can be reduced depending on the read and the human operator error, greatly improve work efficiency.
5 has a variety of protective devices to improve the safety and reliability.
Independent control system, easy maintenance and replacement.
Laboratory muffle furnace body has opened a vent hole (additional gas shielded intake and exhaust air) according to user requirements.
8 other product specifications according to user needs. Kinds of non-standard tube furnace, pit furnace, box furnace.

Heat treatment resistance furnace design requirements

Heat treatment resistance furnace designed primarily considered a key part of the hob, furnace shell, lining, mouth devices.
First, hob and furnace shell
The role of the hob to bear the load of the lining and the workpiece and the support side of the furnace arch thrust (referring to the box-type furnace vault). Hob usually consists of steel welded into a frame, steel plate, the design reasonable hob and furnace shell should be strong enough, some unscrupulous manufacturers tend to cut corners with little or sheet instead of thick plates earn interest.
The furnace shell role is to protect the lining of, reinforcement furnace structure and maintain the tightness of the electric furnace, which is usually attached to the steel frame welded steel complex. Small laboratory furnace or not to set the oven rack, with thick steel plate welded furnace shell, may also play the role of the hob. The furnace shell thickness not generally in the 2 to 6 mm, and the hearth with a thicker steel plate, the side walls for availability thin steel sheet production. In addition to the protective atmosphere or controlled atmosphere furnace generally use intermittent welding.
Second, the lining
The lining of the role is to maintain the furnace temperature, reducing heat loss, good lining material only have a certain refractoriness, resistance to thermal shock, but also have less heat storage capacity and a certain intensity. The lining is usually the use of lightweight refractory bricks and fiber, except to the extent that it is required to support the site in the mouth or due to gravity.
Third, the furnace port device
Furnace mouth device includes a door (lid), door guides (oven panel) and the clamping device. Furnace mouth device should be well sealed, less heat loss, the door should be larger than the mouth, usually on each side of the door and mouth overlapping 65-130mm, controlled atmosphere furnace, furnace mouth should be tightly sealed. The door is usually made of cast iron or steel. And put silk brick door put silk brick should be higher than the door frame is indentation 10-15mm.

Compartment quick furnace

Compartment rapid heating furnace Products:
Do not Fragment furnace temperature uniformity throughout the large ingot heating periodic temperature regime (ie furnace temperature divided by the time the warm-up period, the heating period, the soaking period) two chamber furnace types: fixed-hearth chamber furnaces and car bottom furnace the fixed hearth room furnace hearth area generally 1 to 10 m 2. put on a material by manual or simple mechanical; chamber furnaces to heat a larger workpieces, put on a feeder with a special fuel for coal, heavy oil or gas to some furnace in the furnace wall to open a gap, the blank gap into the furnace heating called seam furnace, heating commonly used in small pieces or the long billet ends or local heating of this type of furnace hearth yield per unit area is usually 300 to 400 kg / (m 2 ·), specific heat consumption per ton of steel is about (1.0 to 1.5) × 106 kcal car bottom furnace for ingot weight of more than ten tons to hundreds of tons of heating before forging, furnace chamber or tunnel. heating 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, so the car bottom furnace normally distributed heating and dispersing smoke (burner and smoke crossing dispersed arranged on the side of the furnace wall).
Compartment rapid furnace work:
Stars chamber quick heating furnace heating chamber placed in a line by a certain compartment provided between the heating chamber and the heating chamber, the transfer roller of the preform is provided in the indoor blanks single (or double root) to which is heated by the heating chamber and the chamber between each heating chamber and adjacent compartments constitute a furnace section, so called furnace section. furnace for rapid heating, oxidation and decarburization applicable in heated circular blanks and steel pipe. compatible with the planetary mill, can be used to heat the continuous casting slab; localized heating of certain steel disadvantage is the low production capacity per unit length of the furnace, the lower the thermal efficiency of the furnace chamber The furnace used for heating before the metal billet or ingot forging does not move when the material is heated;