Thermochemical Stability of Ceramic Fiber Modules

The ceramic fiber module has excellent chemical and thermal stability. The ceramic fiber module has excellent elasticity. The module is in a static state. After the furnace lining is built, the ceramic fiber module expands so that the furnace lining has no cracks and can compensate for the shrinkage of the fiber furnace lining to mobilize the thermal insulation function of the fiber furnace lining. The group function is good; ceramic fiber module The installation is fast, and the anchors are attached to the cold surface of the wall lining, which can reduce the requirements for the texture of the anchors. Insulation design and construction training can be carried out according to user needs.

The ceramic fiber module is a new type of furnace lining product to simplify and speed up the construction of the furnace and mobilize the group character of the furnace lining to replace the traditional heavy refractory materials, which drives the improvement of furnace masonry skills.

Ceramic fiber modules are used in many industries, such as the lining insulation of petrochemical industry kilns; the lining insulation of smelting industry kilns; the lining insulation of ceramics, glass and other hardware industries; the lining insulation of heat treatment furnaces in the heat treatment industry; Lining of other industrial kilns.

How to Construct Ceramic Fiber Modules

Brief description of ceramic fiber module construction method:

1. By welding the stainless steel screw rod on the furnace wall or the top, the screw rod is inserted into the module to a certain depth during installation, and the nut is sent into the module with a special tool from the furnace side of the module to fasten it. There is no special requirement for the radiation chamber, as long as it is basically flat, cleaned and weldable.

2. In general, modules are not used directly for the fire door, but light castable or ceramic fiber is used for the fire hole and other structures. Explosion-proof door openings can be directly made with modules, and standard anti-riot doors can generally be selected.

3. Modules generally do not need to be sprayed. Modules are not suitable for areas with large erosion and abrasion.

4. There is no need to use the module in the transformation to involve the furnace tube, and there is no problem when the furnace tube passes through the ceramic fiber. Only a sealed box is required, and the furnace tube is not required.

5. Generally, you can design and install it for you if you are a module construction unit, especially for renovation projects, you do not need to specifically ask the design institute to do the module design and installation.

How to Preserve Ceramic Fiber Board

Ceramic Fiber Board is a high-strength fiber product produced with specific refractory additives. Ceramic fiberboard has tough texture, high compressive strength, superior high temperature resistance and excellent supporting power, and is a necessary refractory material for high temperature components. So how to preserve the ceramic fiberboard so that it can exert its high temperature resistance characteristics, let's understand together:

Ceramic Fiber Board is made of ceramic fiber as raw material and vacuum formed. Its strength is higher than that of fiber blanket and vacuum forming felt. The ceramic fiber forms a mass when it meets water, and the hardness of ceramic fiber board becomes lower immediately when it meets water. Falling off, and the nemesis of ceramic fiber is water. Therefore, how to waterproof during storage will be very important.

The storage environment of Ceramic Fiber Board is to be dry, water-free, and non-humid. The building does not leak or seep on rainy days, and keep the indoor environment dry. The ceramic fiber board uses a waterproof plastic film inside and a carton package on the outside. Use a pallet to place the floor on the pallet. The ceramic fiber board is placed on the pallet. It is forbidden to touch the ground and store at least 20 mm above the ground. In the rainy season, cover the ceramic fiber board with waterproof canvas, pay attention to the wall water seepage.

Ceramic Fiber Board is an industrial product used in a variety of high-temperature, high-pressure, and easy-to-wear environments. With the development of technology and the improvement of people's living standards, ceramic fiberboard is more and more widely used. It must be processed before use. Good preservation can maximize its effectiveness.

Why Use Ceramic Fiber Rope

Ceramic fiber rope is a multi-functional material with very good fiber properties. It can be made into various types according to requirements. Everyone can better understand and use the product. Let's introduce to you, its scope of use and what are its outstanding properties when in use?

Ceramic fiber rope is made of ceramic fiber as raw material. The conditions of installation and use of ceramic fiber products are different. There are two weaving methods. One is to use aluminum silicate fiber, and Zhang Zhuoweixin uses inorganic fiber for external bonding. Stainless steel wire or nickel-chromium iron and heat-resistant and corrosion-resistant alloy steel wire are woven and processed by a braiding machine, so that the product (https://refractoriesmaterials.com/ceramic-fiber-rope/) has very good tensile strength. Another method is to add 5% to 20% aluminum silicate fiber Organic fiber, directly textile city Qianv4 is woven into ceramics, products, he can not support and middle, will be the product. The product is mainly used as a high-density sealing material, widely used to replace asbestos to prevent environmental pollution, and cannot be widely used in high-heat furnaces. It can also be used to weave into a net, and produce different specifications as high-temperature filter materials. Solve the problem of high-temperature heat-proof coverings of raw materials, fire-proof curtains and heat insulation layer in furnace

Knowledge of the Density of Ceramic Fiber Board

 

1. What is the density of ceramic fiber board?

Commonly used is 250-450kg per cubic meter, and the density of wet-formed ceramic fiberboard is 280-320kg per cubic meter. No matter how light it is, it is called ceramic fiber felt in the national standard, and the density can be about 700. The dry-process board is formed by spraying adhesive and mechanically pressed. It has low density and has good elasticity and flexibility. It is generally used for heat preservation and sealing. The wet-process adopts water-washing mold vacuum forming. The board has high density and good hardness. Mechanical processing, generally used for fire-resistant insulation;

2. What is the hardness of the ceramic fiber board?

Speaking of the density of ceramic fiberboard (https://refractoriesmaterials.com/ceramic-fiber-board-for-sale/), we have to mention its hardness. In fact, the hardness of ceramic fiberboard is related to its density, material and technology. The density has been mentioned above, let me talk about the materials, ceramic fiber materials mainly include alumina, silica, and zirconia;

3. Is ceramic fiber board poisonous?

Ceramic fiberboard is an inorganic material. Glue needs to be added in the process of production and processing. It will smoke after burning, so it will harm the human body. However, as long as protective measures and safe handling are taken, the problem should not be big.

What is Silicon Carbide Refractory Brick

Silicon carbide refractory bricks are special refractory materials produced from silicon carbide (SiC). It has good wear resistance and corrosion resistance, high temperature strength, high thermal conductivity, low linear expansion coefficient, and good thermal shock resistance. Silicon carbide refractory bricks (https://refractoriesmaterials.com/silicon-carbide-brick/) can be classified according to the content of SiC and the type of binding phase.

 

What are the Types of Silicon Carbide Refractory Bricks?

The performance of refractory bricks depends to a large extent on the condition of the combined phase. According to the bonding phase, silicon carbide refractory bricks can be divided into: oxide bonding-aluminum silicate, silicon dioxide as the bonding phase; nitride bonding-silicon nitride (Si3N4), silicon oxynitride (Si2ON2) or Long is the binding phase; recrystallization-silicon carbide particles are directly combined by recrystallization; semi-silicon carbide refractory bricks can be divided into many types, such as clinker silicon carbide refractory bricks + high aluminum silicon carbide refractory bricks, Zircon silicon carbide refractory bricks, silicon carbide graphite refractory bricks, mullite silicon carbide refractory bricks and corundum silicon carbide refractory bricks, etc.

Main Properties of Refractories for Coke Ovens

 (1) Porosity The pores in refractory products include open pores and closed pores. Porosity generally refers to the percentage of the volume of the apparent pores communicating with the atmosphere to the total volume of the product, also known as the apparent porosity. The porosity of the product is smaller, the thermal conductivity is better, and the compressive strength is higher, but the resistance to rapid cold and heat is poor.

(2) Bulk density and true density Bulk density is the mass number of bricks per cubic meter including all pores, and the brick-like volume when calculating true density only includes rock parts. Since the true density of different crystal forms of quartz is different, the firing situation can be understood through the true density of the brick. A better fired silica brick has a lower true density.

(3) Compressive strength at room temperature The pressure that a product can withstand per unit area at room temperature is called compression strength at room temperature. The structure is uniform and compact, and the product is well-fired and has high compressive strength at room temperature.

(4) Thermal expansion is usually expressed by the average linear expansion rate within a certain temperature range.

(5) Thermal conductivity refers to the performance of refractory products to transfer heat. Expressed by thermal conductivity, its unit is W/(m.℃) bricks with low porosity and dense structure, good thermal conductivity. The thermal conductivity of most refractory products such as silica bricks and clay bricks increases with increasing temperature, but there are also a few refractory products (such as magnesia bricks and silicon carbide) whose thermal conductivity decreases as the temperature rises.

(6) Refractoriness Refractoriness refers to the performance of refractory products to resist softening (melting) at high temperatures, and refers to the temperature at which the top of the refractory cone sample is bent and touches the side of the chassis.

(7) The softening temperature under load indicates the ability of refractory products to resist temperature under a certain load. The load softening temperature is the sample under a pressure of 0.2 MPa and heated at a certain heating rate. As the temperature increases, the sample continuously deforms. The temperature when the height of the sample decreases by 0.6% is the load softening temperature. It is related to the chemical properties of refractory products, the characteristics of crystal structure, the viscosity of the glass phase at a certain temperature, the relative ratio of the crystal phase to the glass phase, the firing temperature and the particle size composition.

(8) High-temperature volume stability refers to the property of irreversible changes in volume of refractory products when they are used for a long time at high temperatures. The volume stability of refractory products is usually expressed by residual expansion (or shrinkage). The specific index is: the refractory product is heated at a certain temperature for a certain period of time, and after natural cooling, the volume change is measured. The percentage of this value to the original volume is called residual expansion (or residual shrinkage).

(9) The ability of thermally stable refractory products to resist sudden changes in temperature without being damaged. The test method is to put half of the sample in the heating furnace, and the other half outside the furnace, heat it to 850℃ for 40 minutes, and then put it in a flowing cooling water tank for rapid cooling. Repeat this process. When it damages the quality of the dropped part It is the number of quenching and quenching when the mass of the original sample is 20%. It is closely related to the expansion coefficient of the product, the unevenness of the internal temperature distribution of the product, and the shape and size of the product.

(10) Corrosion-resistant refractory products are resistant to the chemical and physical effects of molten slag and charge decomposition products at high temperatures. The main factors affecting corrosion resistance are: the chemical composition of the product and the slag, the working temperature, the nature of the decomposition products of the charge, and the density of the product.

Refractory Materials Used in Open Furnaces

 

After the open-hearth furnace adopts oxygen blowing to strengthen smelting measures, the output has doubled and the fuel has been significantly reduced. However, it was accompanied by a sharp increase in the amount of furnace dust in the furnace, severe splashing of molten slag and molten steel, increased furnace temperature, and deterioration of the service conditions of the furnace lining, especially the damage of the furnace roof. In order to meet the needs of open-hearth furnace oxygen-blowing intensified smelting technology, on the one hand, it is to improve the structure of the furnace body, and on the other hand, it is to improve the quality of the furnace lining refractories.

With the adoption of open-hearth intensified smelting technology, the refractories used in open-hearth furnaces have also changed, and refractory materials are developing in the direction of high-grade, such as various direct combined magnesia chrome bricks, recombination and fusion cast magnesia chrome bricks, magnesia alumina spinel Brick etc.

The spray part of the open-hearth furnace lining is also an effective measure to improve the age of the furnace. At present, the semi-dry method and flame spraying have a better effect, and the spraying material is generally magnesium.

Refractory Fiber Classification

Refractory fiber (also known as ceramic fiber) material is a new type of refractory material developed in the past ten years. It overcomes the inherent brittleness of refractory bricks and unshaped refractory materials, so the scope of application is rapidly expanded. This point has been briefly introduced in the article "Refractory Materials Used in Hydrocarbon Cracking Furnaces" published yesterday. Refractory fiber furnace walls have many advantages: heat resistance, good heat insulation performance, small heat storage, light weight, thinner and lighter furnace walls can be obtained under the same conditions; elasticity, good resistance to mechanical vibration and thermal shock, It also has excellent electrical insulation and sound absorption properties; simple structure, convenient construction, suitable for parts with complex shapes. Disadvantages: poor scour resistance, so convection chambers with soot blowers and chimneys with high flue gas flow rates should not be used. According to experts from Henan Refractory Material Factory, refractory fibers are divided into three categories according to their chemical composition: ordinary aluminum silicate refractory fibers, containing 46%～48% AL2O3, 52%～53% SiO2, operating temperature 1000～1200℃; high alumina refractory Fiber, containing 56%～64% of AL2O3, 35%～44% of SiO2, using temperature of 1200～1400℃; refractory fiber containing chromium aluminum silicate, containing 4% of Cr2O3, using temperature of 1300～1400℃. According to the shape of the product, there are felt, blanket, paper, belt, rope and special-shaped products. Nowadays, the refractory fiber used in the wall of the tube furnace generally contains about, and only the surface directly in contact with the flame is a soft felt with high alumina refractory fiber containing 60% Al203 and methyl cellulose as the binder. It has good heat resistance and thermal insulation properties. In fact, it is more expensive, so it is only used as a refractory layer. Generally, cheap rock wool boards or slag wool boards are used for the insulation layer. There are two types of refractory fiber lining structure: layer lining and stacking.

Maintenance of Refractory Castable

Maintenance is one of the key elements that harm the performance indicators of refractory castables, and it is an element that is easily overlooked. Maintenance is to give the fusion agent in the refractory castable one time for setting and hardening, and then to obtain sufficient early compressive strength. Maintenance rules and regulations are related to the type of fusion agent for refractory castables. High-alumina cement solidifies faster, the heat of hydration after forming is mostly released within h, the heating value is concentrated, the internal heat is not easily released, and it is also necessary for the concrete near the surface to solidify. The volatilization of water prevents it from solidifying again, and it is also easy to destroy the refractory castable itself caused by thermal stress. Therefore, maintenance should be carried out immediately after the construction of the refractory castable project. It is decided whether to dismantle the mold according to the detailed situation. During maintenance, the surface of the refractory castable can be covered with wet hemp bales or wet mats and immediately sprinkled with water to maintain moisture.