Requirement of Regenerative Heating Furnace for Refractory Materials

In the 400,000t steel rolling renovation project of a company, the heating furnace adopts a high-efficiency regenerative full blast furnace gas heating furnace. The furnace organically integrates the high-efficiency regenerative combustion system, the reversing system, and the furnace, and the air and gas are both preheated to 1000°C. The effective length of the furnace is 30m, the width of the furnace body is 4.3m, and the normal heating capacity is 70t/h.

The furnace is a two-stage furnace type with two arch heating sections, heating, and soaking sections. The soaking section is close to the tapping side and a solid furnace bottom soaking bed is set. The rear part of the soaking section and the heating section use upper and lower sides for heating. Except for the furnace bottom, part of the sidewall, and the heat storage type, the whole furnace is made of bricks. The sidewall working layer and the furnace roof are all cast on-site, sharing nearly 1,000t of refractory materials. Among them, the sidewalls and roof of the key parts of the heating furnace adopt low cement castables specially developed for regenerative heating furnaces.

Rongsheng Low Cement Castable for Sale

Technical Characteristics of Regenerator Heating Furnace

Compared with conventional heating furnaces, high-efficiency regenerative heating furnaces have the following characteristics:

(1) The burner used in the traditional heating furnace is eliminated and replaced with a nozzle hole composed of refractory castables.

(2) The brick chimney with a height of 40-50m for the traditional heating furnace is eliminated and replaced by a steel chimney with a height of only 18m.

(3) The huge air preheater and gas preheater of the conventional heating furnace are eliminated and replaced by two sets of reversing systems and simpler pipelines, air and gas double preheating. The preheating temperature reaches above 1000°C.

(4) The biggest feature of the regenerative heating furnace is that the furnace wall is hollow. Heated on both sides and equipped with a fire vent, the use conditions are harsh.

The Structural Characteristics of the Sidewall of the Regenerator Heating Furnace

The working principle of the regenerative heating furnace determines that the sidewall has the following characteristics:

(1) For hollow walls, it is relatively difficult to install anchor bricks.

(2) The working surface of the hollow wall is heated on both sides, and the inner wall is easily damaged by the dual effects of temperature changes and airflow.

(3) The flame nozzle of the burner and the working layer are combined into one, which affects the service life of the furnace wall.

(4) Since the air gas has been preheated to 1000℃, it is required that the hollow furnace wall should not have large cracks. Air, gas can not be cascaded.

Refractory Requirements for Regenerator Heating Furnace

The intricate structure of the regenerative heating furnace imposes very strict requirements on the selection of refractory materials:

(1) The high-temperature strength of refractories should be large. It must be able to resist the erosion and corrosion of high-temperature airflow and flame during use.

(2) The refractory materials used must have good thermal shock resistance and can withstand frequent temperature fluctuations without cracking or peeling.

(3) Good volume stability, low linear change rate, and high compressive strength. The cavity between the furnace body is not easy to collapse, and no cracks will occur after long-term high-temperature action. Avoid cracks between the air and gas channels and cause explosion accidents.

(4) With slight expansion. The selected refractory material has micro-expansion during use and prevents cracks.

(5) Good sintering performance. During the use process at 1000~1350℃, it should be ensured that the working layer of the wall can be sintered to form a whole to adapt to the working conditions of heating on both sides.

(6) Good construction performance. When the furnace body is constructed, a large number of special-shaped modules need to be installed. The local gap is extremely small, and in some places it is impossible to complete the building, so the refractory materials must have good construction performance.

Low Cement Castable Refractory Material

Characteristics of Refractory Materials Selected for Regenerator Heating Furnace

According to the operating conditions of the regenerative heating furnace, the characteristics of the low cement castable used are as follows.

(1) Good thermal shock resistance

The castable has an Al2O3 content of 55% to 67%, and the compressive strength after drying and firing at 1400°C is 15-30MPa and 40-65MPa, respectively. Compared with low cement castables with good aluminum content and high strength, its thermal shock stability is better.

(2) With the slight expansion

Add a proper amount of expansion agent and materials containing aluminum and silicon into the castable. In order to produce micro expansion during use to prevent cracks.

(3) Good sintering performance

By adding an appropriate amount of sintering agent and other materials into the castable. During use at 1000~1350℃, the working layer of the wall can be sintered and formed into a whole. To adapt to its double-sided tropical working conditions.

For more information about refractories for regenerator heating furnaces, please visit our website: https://kilnrefractory.com/.

Sodium Silicate

Sodium silicate (Molecular Formula – Na2SiO3, Molecular Mass – 122.06 g/mol) is a white solid that is soluble in water, producing an alkaline solution. There are various states of this compound; all are glassy, colorless, and soluble in water. This is also called water glass or liquid glass in manufacturer.

Sodium silicate is stable in neutral and alkaline solutions. In acidic solutions, the silicate ion reacts with hydrogen ions to form silica acid, which when heated and roasted forms silica gel, a hard, glassy substance.

Uses of Sodium Silicate

· Egg Preservation – Sodium silicate is used as an egg preservation agent. Eggs can remain fresh by using this preservation method for up to nine months.

· Automotive repair – One of the popular uses of Sodium silicate is seal leaks at the head gasket.

· Cement uses – Sodium silicate has been widely used as general-purpose cement, especially for applications involving cementing objects exposed to heat or fire.

· Timber treatment – Treating wood with sodium silicate preserves wood from insects and possesses some flame-retardant properties.

· Concrete and masonry treatment – Concrete treated with a sodium silicate solution helps to significantly reduce porosity in masonry products like concrete and plasters. Applying Sodium Silicate with concrete permanently binds the silicates with the surface making them far more wearable and water repellent. These coatings are known as silicate mineral paint.

· Water Treatment – Sodium Silicate is used in water treatment in wastewater treatment plants. Water glass used to bind heavier molecules and drag them out of the water.

· Refractory use – Water glass is useful binder of solids, like vermiculite and perlite. When blended with these lightweight aggregates, water glass can be used to make hard, high-temperature insulation boards used for refractoriness’, passive fire protection and high temperature insulations, such as mounded pipe insulation applications.

For more information visit: http://www.refractoryonline.com.

 

Diverse Functions of the Multi-Purpose Water Glass

That sodium silicate is regularly used to bind sand particles to form a solid and usable mold is old news. It is also common knowledge among artists that the same sodium silicate compound is often used to create a lovely antique patina on different types of refractory ceramic products.

However, not many people (artists included) are aware of the other varied uses of this multi-purpose compound popularly known as water glass or even liquid glass.

Bonding and sealing – Sodium silicate works as an excellent adhesive for bonding and coating applications. Apply a thin layer between two materials and let it air dry. The acidic reaction will form a hard glassy gel that effectively functions as a rigid, resilient and tightly adhering bond. The ‘glue’ bond will be resistant to moisture, fire and even high temperatures. As water glass is available at quite a low price in the market, it becomes the most cost-efficient adhesive for different materials like metals, paper, plaster, refractory ceramics, glass, fiberglass and even refractory materials.

Similarly, it can also be used to make porous concrete and plaster quite waterproof. Again, apply a thin coat on the surface that will bind to the refractory concrete and seal it, not allowing water or other liquids to permeate through it.

Deflocculant – You will be surprised to know that sodium silicate is also a commonly used deflocculant for clay. A major issue with clay slips is that they contain a lot of water which causes the slip to shrink as it dries. This item is used to thin the clay – it works by dispersing the particles which greatly reduces its viscosity.

However, you need to mix the clay, water and water glass in a precise ratio with the latter never exceeding.5% of the entire formulation. This is essential due to the fact that after this point water glass starts having a starkly opposite effect on the clay mixture. Excess water glass will paradoxically make the clay thicker or flocculate it!

If you cross the fine boundary, you will have to add more fireclay to get the desired consistency or just discard the mixture altogether. Therefore, it is advisable that beginners should add small amounts of liquid sodium silicate for deflocculation before they get a hang of the procedure and ratios. Yet, the cheap price again makes water glass compound the most low-cost deflocculant possible for clay!

In sum, water glass suits a varied range of applications. And while you are putting this compound to different uses, you can rest assured that the inorganic sand and alkali present in the water glass are completely non-toxic and safe for the environment as well. Just ensure that you seal the containers properly and store them in a cool, dry and well ventilated area. It is better not to allow it to freeze either. Unopened and properly stored containers can last long, really long!

The author, Aarron Barry is an enthusiastic writer who loves writing on creativity, art likes topic and attention the detail. Through this article he shared his valuable information on water glass, sodium silicate or silicone mold. Want to know more about those topics, visit the website www.refractoryonline.com.

 

Blacksmith Gas Forge Basics On Refractory Materials

A Gas Forge May Be The Solution For Your Work Shop

The modern blacksmith may use either a solid fuel forge such as a coal forge or a gas forge The coal forge is still the most versatile, but a propane gas forge is the most convenient. Gas forges run at a bit over 2000 degrees Fahrenheit, which is certainly enough to do general forging.

The propane forge is actually an insulated box of various sizes and shape, that have one or more burners in the top or the side. The burners may be atmospheric or have an electric blower attached to them. The chamber holds the heat to heat the bar, and the burner provides the heat. Of course with a propane gas forge you are limited by what you can fit in the box.

The refractory insulation in a blacksmith gas forge is a high temperature ceramic fiber. Trade names are Kaowool, Durablanket, or Fiberfax. This insulation allows the high temperature inside the gas forge but prevents the outer shell from deteriorating. Hard or soft firebrick can also be used to lock the heat in the forge chamber.

In some blacksmith gas forges the insulation material is a castable refractory. This is more like a concrete that you mix up and shape to your gas forge chamber. This is more of a heat shield than an actual insulator. This type of gas forge will take a while to heat up. Refractoryonline.com acts as a heat sink until it has soaked up enough heat that it reaches an equilibrium between the high temperature inside and the loss to the environment.

The refractory is more durable than the common fiber insulation, but you sacrifice thermal efficiency. It is also much heavier than the Kaowool insulation. The castable is much less flexible than the fiber insulation as well. This means that it will crack with repeated heatings. This may not be a problem as the pieces usually do not fall out.

The option of a gas forge is a great bonus to the modern blacksmith. For those that want a quick heat source with minimal maintenance, such as hobby blacksmiths it is ideal. Many professional blacksmiths make their living with a propane forge,and only use a coal forge occasionally.

The small size of a propane forge means that it can be quite portable. Many hobby smiths will easily move a propane forge out into the driveway, or just outside a shed for use. They are ideal for hammer ins as well.

Gas Forges are able to be purchased from many supplies or a blacksmith can make his own gas forge with only a few basic tools of a welder, drill press, and metal cutter.

 

 

 

How Does the Quality of Steel Mold Flux Matter in Steel Manufacturing?

With the demand for steel growing every year, the size and scale of the global steel manufacturing industry has also been growing. Consequently, there has also been an equally rapid growth in the demand for the auxiliary materials required in the steel making process. Among the most important additives materials in the process is the steel mold flux, which is an essential material for removing impurities out of steel in the early manufacturing processes. Also called the mould flux or molding flux, the granular or powdery material needs to be used in the right quantity at the right time in the steel manufacturing process, usually when the steel is in liquid form that is freshly derived from the iron ore.

How is steel mold flux derived?

Steel mold flux have been popularly used by steel manufacturers since the mid 20th century. Steel mold flux are usually manufactured or derived from by one of the two compounds Calcium Oxide (CaO) or Dolomite-CaMg(CO3)2. In nature these compounds mostly exist as solid rocks often in mixture with other materials. Hence, to make them suitable for use as flux in the steelmaking industry they are crushed, sorted and purified to obtain purified powder or grains. In the steel manufacturing industry, the flux is prominently used in the continuous casting process. It is fed into vessels containing hot liquid steel following which they function as slag which absorbs the impurities of the steelmaking process.

Why is getting the right quality of flux important?

Steel manufacturers typically produce several varieties of steel in blast furnace that is built with sillimanite bricks and http://kilnrefractory.com/castable-refractory according to the preferences of their customers. However, for the control of the steel production process it’s absolutely essential to have the right kind of auxiliary materials including manufacture refractory materials, casting auxiliaries and metallurgical slag additives. In simple terms, only the right quality of flux can absorb the impurities in a controlled and effective manner. Components in the flux help not just in the oxidation process but also ensure that the right composition of carbon and steel is maintained from early on. Thus, in short, the better the quality of the flux, the better is the quality of the manufactured steel.

Get your flux from the right producers

Reputation and experience of the producers or suppliers must be important indicators aside from the price, when you are looking for the right party to provide you the steel mold flux for your steel mill. For instance, companies could be trusted to bring their customers the right product, considering the fact that they have been in the business for over a decade and have established relationship with a lot of the major steel producers in Asia. With the right flux, steel manufacturers can keep making high quality steel on a consistent basis and keep on winning the trust of their customers.

Firebricks and castables are important refractory material for sale in www.refractoryonline.com as furnace building materials. The most important additives materials in the process is Steel Mold Flux, which is an essential material for removing impurities out of steel in the early manufacturing processes.

 

Refractory Materials Dry-Out Provides Safe Prevention of Potential Industrial Hazards

Refractory materials are used in industrial structures like furnaces, boilers, incinerators, and chemical reactors to protect them from intense heat. What they do is provide a type of insulation from the heat which these structures are exposed to; heat which can damage them and increase the need for costly repairs. But there are also problems which can arise during the creation process of refractory which can have damaging or even dangerous effects.

When refractory material is created it is done in the same way which cement is created when it is mixed with water. As refractory is heated it becomes solid. However, if this happens to fast sometimes the moisture doesn’t have the chance to dry up and it becomes trapped inside the solid refractory.

And then what?

Well, when kilnrefractory.com heats up that moisture starts to expand. In most cases the result is mere cracking, but if the expansion is severe and rapid enough it’s like setting off a bomb. So refractory dry out provides a safe and effective way for removing this moisture and thus preventing the possibility of expansion or explosion.

The way it works is high velocity burners use a combination of intense pressure and near one thousand degrees Fahrenheit heat to remove moisture from the refractory at a safe rate. This heat is applied at an ambient temperature at first and is slowly increased over a prolonged period of time. In some cases, proper dry out process can take over two hundred hours. This is because the refractory has to have the time to dry out and to solidify properly in order to ensure for a stronger end product.

Therefore his controlled temperature adjustment period is crucial to accomplishing a safe and effective means of refractory solidification. This means not only a stronger more solid refractory lining, but also for removal of mechanical and chemical water which keeps cracking and explosive spalling from ruining the structure. Proper refractory dry out also applies hot, cold and intermediate thermocouples to ensure proper through wall temperate gradients within refractory linings. This process causes something called ceramic bonding which prevents sagging in dual component linings, resulting in a stronger refractory and safer structure.

Some of the industries which require refractory dry out are: foundry, glass, aluminum, cement, ceramic, refineries, chemical plants, power plants, and steel mills. These industries all use furnaces, kilns, chemical reactors, and incinerators and therefore utilize refractory materials in order to protect them from the intense heat used to operate them. This requires proper application of refractory dry out technologies for the sake of a safer operating environment and a greater durability and lifespan of their structures.