insulating castables Archives - Rongsheng Refractory Castable Cement for Sale Manufacturer and Supplier

Refractory Castables Materials for Rotary Kiln Insulation

March 18, 2023 by rsrefractorycastable

Due to the structure and working characteristics of the rotary kiln, as well as the diversity and complexity of the materials it handles, the requirements for the temperature of the outer wall of the rotary kiln are also different. From the perspective of environmental protection and energy saving, reducing the temperature of the outer wall of the rotary kiln as much as possible, doing a good job in the insulation layer of the rotary kiln, and the configuration of the refractory lining material of the rotary kiln are all the enterprises that operate the rotary kiln expect. Rongsheng monolithic refractory manufacturer has rich experience in the production, sales, and application of monolithic refractory materials. We have served various types of rotary kilns, which can help you solve the problem of rotary kiln insulation lining. Get pricing information for free.

Lightweight High-Strength Castable for Steel Ladle — Lightweight High-Strength Castable Refractory

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There are also various designs for the thermal insulation lining of the rotary kiln, and the types of refractory materials used are also various. According to the specific needs of customers, we can provide customers with insulating castables, lightweight castables, lightweight plastics, dense refractory plastics, heavy wear-resistant castables, phosphate-bonded composite insulation bricks, ceramic fiber products, etc.

Working Layer and Thermal Insulation Layer of the Rotary Kiln Lining

When the rotary kiln lining refractory material is selected, the next step is to evaluate the heat loss of the rotary kiln body.

When we realize that the working temperature in the rotary kiln is high, and the material has serious erosion and wear on the inner lining, then the inner lining design must consider the double-layer inner lining, and the two inner linings are respectively called the working layer and the thermal insulation layer.

The working layer is made of heavy refractory materials to meet the resistance to high-temperature flames and material erosion and wear; the heat insulation layer is made of light refractory materials to improve the thermal insulation performance of the inner lining and reduce the heat loss of the rotary kiln body.

The inner lining of the rotary kiln has a thermal insulation layer, which can effectively reduce the heat loss of the rotary kiln and also help protect the rotary kiln shell and other shell components.

Generally speaking, the rotary kiln lining with a thermal insulation layer is often used for rotary kilns with high operating temperatures. The refractories of the inner lining of the thermal insulation layer and the inner lining of the working layer have similar chemical compositions, and the difference between Rongsheng refractory materials lies in their respective strength and thermal conductivity. The refractory material lining the thermal insulation layer has a low density and low strength, but its thermal resistance is relatively large, which can effectively reduce the heat loss of the rotary kiln body.

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What Refractory Castables are Used for Each Part of the Cement Rotary Kiln?

Refractory castables are used as the main insulation material for the new dry-process rotary kiln. If it is properly configured, it can protect the normal operation of production equipment at high temperatures and effectively reduce system energy consumption.

Cement Rotary Kiln Refractory Castable

Kiln mouth with refractory castables. At the kiln mouth in front of the rotary kiln, the clinker outlet temperature is around 1400°C, and the temperature of the secondary air entering the kiln changes frequently due to kiln conditions. With the expansion of the scale of the cement plant, the amount of clinker at the kiln mouth is also increasing, and the thermal stress and mechanical stress on the refractory castable at the kiln mouth increase accordingly. For this reason, the kiln mouth refractory castable should have sufficient refractoriness, mechanical strength, thermal shock stability, and alkali resistance under high-temperature environments. It is recommended to use high-performance kiln mouth special refractory castable or improved kiln mouth special refractory castable. The product has excellent anti-stripping performance, high temperature and alkali resistance, and cement clinker erosion resistance.
Refractory castables for burners. The working environment of the burner is about 1400°C, the flame temperature is about 2000°C, and it works in an alkaline atmosphere for a long time. Compared with the front kiln mouth, the temperature changes more frequently and the temperature difference is larger. Therefore, the requirements for its thermal shock resistance are higher. The front end of the burner is always scoured by the high-temperature airflow entrained with clinker dust, especially the lower part is more severely scoured. Therefore, burner refractory castables need sufficient wear resistance. It is recommended to use special castables for burners or special refractory castables for improved burners. The product has excellent spalling resistance and thermal shock stability.
Refractory castables for kiln hood and grate cooler. For some large rotary kilns, the heat load on the lower part of the kiln hood is relatively high. If the general high-alumina refractory castable is not well controlled for curing and temperature rise, it is prone to bursting and falling off. The top of the kiln hood is close to the tertiary air duct, and the erosion of the dusty airflow is relatively serious, and the construction of the top castable is relatively difficult, and the requirements for the fluidity and early strength of the material are relatively high. The working temperature at the top of the front end of the grate cooler is high, and the temperature changes greatly. The low walls on both sides of the front end have been worn by the high-temperature clinker coming down through the kiln mouth for a long time, and they are also damaged by certain mechanical stress and thermal stress. It is recommended that these two parts use high-strength wear-resistant castables with good high-temperature performance, strong thermal shock resistance, and wear resistance.
Refractory castables for tertiary air pipe elbows and air valves. This part has a large change in heat and cold and is washed by high-temperature clinker particles. The castable is prone to loosening and peeling, and it is the most prone to wear and tear during the operation of the cement plant. It is recommended to use wear-resistant refractory castables.
Refractory castables for C4 and C5 cones and their discharge pipes, calciner cones, and smoke chambers. These areas are prone to crusting and are difficult to remove. Cleaning needs to be done manually with iron tools, which will inevitably cause mechanical damage to the refractory castable. Once severe skinning occurs, the kiln needs to be stopped for treatment. It is recommended to use high-strength anti-skinning silicon carbide castables.
Refractory castables are used for other parts of the cement rotary kiln. It is recommended to use high-strength alkali-resistant castables for C1~C3, high-temperature high-strength alkali-resistant castables for C4 and C5 (except for the cone), and high-strength wear-resistant castables for the decomposition furnace.

Rongsheng Insulation Castable Manufacturer

The application and development of refractory and insulating castable refractory should conform to the concept of environmental protection and circular economy. Reasonable selection of thermal insulation castables can prolong the service life of the rotary kiln castable lining, effectively protect equipment, reduce system heat loss, reduce system crust blockage, reduce kiln shutdown times and maintenance time, and improve system operation rate. To achieve the purpose of stable production, high production, and low energy consumption of the kiln system. For a case study on the configuration of thermal insulation and refractory materials for the rotary kiln project, please contact us. We will provide you with the most suitable thermal insulation refractory solutions for your production needs according to your working conditions.

How to Use Insulating Castables to Reduce the Surface Temperature of the Kiln Skin?

March 3, 2023 by rsrefractorycastable

The temperature of the shell of industrial kilns varies, and the higher the operating temperature, the higher the temperature of the shell of the kiln. In recent years, due to the requirements of environmental protection and the advocacy of energy conservation, industrial kiln enterprises have paid more and more attention to the temperature of the outer wall of the kiln skin. So how to reduce the temperature of the outer wall of the kiln skin? To reduce the surface temperature of the kiln skin, how to use insulating castables?

Generally, if you want to lower the temperature of the kiln skin, you must improve the use of insulation materials, or thicken the insulation layer. There are many light clay bricks and light fiberboards, cotton wool, and blankets used for the insulation layer. If you use fiber insulation materials, you don’t need lightweight clay bricks, and you can’t use fiber insulation materials if you use lightweight clay bricks. However, if it is required to reduce the temperature of the kiln skin, it is necessary to do multi-layer insulation to reduce the degree of heat diffusion and reduce the temperature of the outer wall of the kiln.

What kind of material should be used as the insulation layer when the kiln skin temperature is required to be 50°C?

When the temperature of the kiln skin is required to be 50°C, insulating castable refractory can be used, and fiberboard can also be used as the insulation layer.

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The kiln skin temperature is required to be 50°C, and the temperature requirement is relatively low. If you choose fiberboard, it is not enough to use ordinary aluminum silicate fiberboard, you have to use nanometer board as an insulation layer. And it doesn’t work if it’s too thin, the minimum thickness should be 100mm. It is uncertain whether the final kiln skin outer wall temperature reduction effect will reach 50°C on the outer skin. If it is winter, it should be able to meet expectations. If it comes to summer, the temperature of the outer wall of the kiln skin may be 50℃ higher due to the influence of sunshine and weather temperature. This is affected by certain weather factors. If you use a 150mm nanoplate, there is no big problem.

If you use lightweight castable refractory, some costs will be reduced, but the thickness should not be too small. Under normal circumstances, the thickness reaches 300mm, and the temperature of the outer skin can also be lower than 50 degrees Celsius. However, the thickness of the lightweight castable is too thick, which will affect the kiln diameter. Because the insulation layer with a thickness of 300mm, a total thickness of 600mm must be occupied on both sides of the kiln. Therefore, the usable kiln diameter will become smaller. However, from the perspective of heat preservation alone, if it is expected to reduce the temperature of the kiln skin, the temperature required by the kiln skin can also be achieved by pouring 300mm thick lightweight heat-insulating castables.

If the height of the kiln is too high, it is unlikely to use refractory bricks for the insulation layer or the working layer. Because there may be string joints in the middle, the working layer is most likely to be poured with dense castables as the working layer. It is possible to use nano-sheets or lightweight castables for the pouring working layer. Because the outer layer of the nano-plate is wrapped with plastic, no moisture will enter, and even if the castable discharges a certain amount of water, the thermal insulation layer will not be affected. If light heat insulation castables are used and dense castables are used in the working layer, they are all constructed by pouring, and there is no problem of water discharge affecting the use of the heat insulation layer.

Therefore, when the external temperature of the kiln skin is low, it is possible to use nano-plates and lightweight insulating castables. Only the thickness has certain requirements. The thickness of the nano-plate should not be less than 100mm, and the thickness of the lightweight castable must be constructed to a thickness of 300mm to meet certain usage requirements.

Can Lightweight Insulating Castables be Used Outside the Furnace Shell?

Lightweight insulating castables are used on the outside of the furnace shell and are not recommended. Because the lightweight insulating castable refractory plays the role of heat preservation and heat insulation, the main function is slowing the heat dissipation, which can save fuel and protect the furnace shell.

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If the furnace lining is not used as an insulation layer during construction, it is not recommended to use it in this way. If there is a user unit that has not made an insulation layer and has been put into production, under such conditions, in order to avoid overheating of the furnace shell, it is not advisable to make an insulation layer on the outside of the furnace shell, and then add a layer of the iron sheet on the outside.

The reason is that there is no insulation layer and the temperature of the furnace shell is high. The insulation layer can be used for the next maintenance. If an insulation layer is made on the outside of the furnace shell and a layer of iron sheet is added, the furnace shell will also be attacked by high temperature and the service life will be shortened.

There is a furnace type with heat-insulating material coated on the outside of the furnace shell. Due to the high temperature of the boiler, heat-insulating castables or heat-insulating bricks are used as heat-insulating layers on the inner lining. Some manufacturers also apply a layer of fabric on the outside of the furnace shell, which also slows down the temperature and heat dissipation process. This saves fuel and protects the furnace shell. There are also manufacturers who use a layer of epoxy paint on the outside of the furnace shell, but not many use this method. On the contrary, more fabrics are used.

If the inner lining is made of light-weight insulating castable or light-weight bricks as the insulation layer, if the insulation layer is made outside the furnace shell for remedy, it will not play any role in the protection of the furnace shell, and it is of little significance to make the insulation layer. Even doing it with nanoplates doesn’t make much sense.

Therefore, the selection of lining materials must be determined according to the temperature of the lining. Whether to use lightweight insulating castables refractory or lightweight refractory bricks or use insulation cotton and boards as insulation layers. If the furnace lining temperature does not exceed 200°C, there is no need to make an insulation layer. If the temperature exceeds 1000 ℃, it is necessary to make an insulation layer. If the temperature exceeds 1400°C, high-grade lightweight materials should be used as the insulation layer.

Rongsheng Refractory Castable Manufacturer

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Solutions to Reduce Kiln Skin Surface Temperature

Rongsheng refractory material manufacturer is a manufacturer with rich production and sales of refractory materials. Our monolithic refractory materials offer reliable performance. It has a long service life on the refractory lining of various industrial kilns. Extend the service life of the refractory lining. Recently, our technical team is also working on the research of refractory materials that reduce the surface temperature of the kiln skin, providing cooling solutions for industrial kilns. Contact us for a free solution.

Advantages and Applications of Lightweight Insulating Castables

June 16, 2021July 14, 2020 by rsrefractorycastable

Lightweight insulation castables are composed of high-quality, high-strength raw materials, aggregates and ultra-fine powders, and compound additives. Because the light-weight insulation castable is a powdery and granular refractory material made of certain refractory materials such as alumina and some binders. It has high fluidity and is mainly formed by pouring in construction. Lightweight insulating castables have the advantages of high strength, small volume density, low thermal conductivity, good insulation performance, and convenient construction. It is an ideal choice for industrial boiler insulation materials.

Lightweight Insulation Refractory Castable

RS Lightweight Insulating Castable for Sale

Construction method: vibration or manual ramming construction.

Main function: Insulation and heat insulation to reduce the external temperature of the furnace wall.

Q: How to mix light-weight insulation castable?

A: The mixing of castables requires the use of forced mixers and special mixers.

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Advantages of Lightweight Insulating Castable

The light-weight castable insulation is made of aluminate cement, high-alumina fine material, ceramsite, plus several additives. It has the advantages of high refractoriness, high strength, and low thermal conductivity. The heat preservation casting material of the invention has the characteristics of low thermal conductivity and small volume density, which can reduce the heat and heat energy consumption of industrial kilns and reduce the weight of the furnace lining. In the high-temperature light-weight insulating castable, the raw material of the high-temperature light-weight castable that can be used above 1200°C is a porous material. Mullite, corundum, high aluminum, siliceous and magnesia and other porous clinker or light refractory brick. This castable can be directly used in the lining of 1350℃ atmosphere furnace.

Insulating castable supplier — RS Insulating Castables Supplier

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Lightweight thermal insulation castable has the following advantages:

The high-temperature resistance and high strength.
Low thermal conductivity.
The small volume density, reduce kiln heat consumption.
Convenient construction and reduce labor intensity.
Light texture, reduce the weight of kiln lining.
resistant to acid and acid gas corrosion.
Characteristics of heat insulation, heat preservation, and low water absorption.

In addition, the lightweight insulating refractory castable is not only easy to construct but also the most ideal product for construction with alkali-resistant parts at high temperatures. Moreover, the workability is good, the bonding force is strong, and the initial setting time and the construction operable time are long. The strength increases quickly, the impermeability is strong, no acidification treatment is needed, and it is easy to ensure the denseness and fullness of the masonry gray joints. Can significantly improve the airtightness, integrity, and anti-corrosion ability of the chimney lining wall. It is an ideal cementing material for a high chimney, high-temperature flue, and air duct lining.

The Use of Light-weight Insulation Castable

It is suitable for unshaped refractory materials formed by pouring. It is easy to ensure the denseness and fullness of the masonry gray joints, which can significantly improve the airtightness, integrity, and corrosion resistance of the chimney lining wall. It is suitable for a high chimney, high-temperature flue, and air duct lining. Lightweight insulating castables are mainly used for lining thermal insulation devices such as high-temperature industrial kiln insulation. It can also be used in acid-resistant projects such as acid-resistant tanks and tanks in petroleum, chemical, nonferrous metallurgy, and other industries.

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Lightweight Insulating Castables Manufacturer

Rongsheng refractory castable manufacturer has an annual output of 80,000 tons’ production workshop. As a manufacturer of high-quality refractory castables, the light-weight heat-insulating castables produced have the advantages of moderate strength and good insulation performance. Lightweight insulating castable is made of aluminate cement, high-alumina fine material, ceramsite, and some additives. Lightweight insulating castables have the characteristics of lightweight, high compressive strength, acid and acid gas corrosion resistance, heat insulation, heat preservation, and low count rate. In addition, Rongsheng’s acid-resistant bricks, acid-resistant clay and wipe fabrics, acid-resistant bricks, acid-resistant clay, and wipe fabrics are self-developed refractory materials suitable for thermal insulation of power plant boiler chimneys and heating network pipes. They have the characteristics of acid corrosion resistance, temperature resistance, heat resistance stability, and convenient construction.

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