How to select the refractory materials for your furnace?

06 May.,2024

 

How to select the refractory materials for your furnace?

Refractory materials refer to materials that can withstand high temperature’s physical and chemical actions. There must have refractories as the lining and insulation materials in the kiln/furnace. The selection of refractory materials is extremely important in that it will directly affect the performance of the furnace and the cost of the operation, the life cycle of the furnace, and its maintenance costs. When purchasing refractory products should not only consider their cost but also consider whether their performance and quality could meets your requirements. While, how to make the best choice in the selection of refractory bricks has always been a difficult topic for the buyer. If you also have the same concerns, you can refer to the following principles;

How to select the refractory materialrefractory materials for your furnace?

Refractory materials refer to materials that can withstand high temperature’s physical and chemical actions. There must have refractories as the lining and insulation materials in the kiln/furnace. The selection of refractory materials is extremely important in that it will directly affect the performance of the furnace and the cost of the operation, the life cycle of the furnace, and its maintenance costs. When purchasing refractory products should not only consider their cost but also consider whether their performance and quality could meets your requirements. While, how to make the best choice in the selection of refractory bricks has always been a difficult topic for the buyer. If you also have the same concerns, you can refer to the following principles;

 

 

The key properties of the refractory materials:

 

First of all, we must consider the refractoriness of the fire bricks. Refractoriness refers to the performance of refractory materials against high-temperature actions. Indicates the temperature at which the material softens to a certain degree. The refractoriness must be higher than the actual working temperature. For example, the refractoriness of the fire clay bricks is 1730°C, and its service temperature is 1350°C, the refractoriness of the high alumina bricks is 1790°C, its working temperature is 1430°C.

Secondly, the high-temperature structural strength of the refractories. Refractory fire bricks will withstand a certain pressure during uses, and the structural strength of the material will change under increasing temperatures, so the structural crushing strength is a critical specification for refractory bricks, it basically defines the service temperature of the bricks. This is reflected by its refractoriness under load, and the service temperature of the refractories must be lower than its softening point under load. For example, the refractoriness of the fire clay bricks is 1730°C, and its refractoriness under load is 1350°C, so its highest service temperature is 1350°C.

Third, refractories must have excellent thermal stability. There will be large temperature fluctuations in certain parts of the furnace. For example, when the furnace door is opened, cold air enters. The temperature of the furnace lining drops sharply. This requires the refractory material to have a certain degree of thermal stability to ensure normal operation.

Fourth, refractory materials require high-temperature chemical stability. At high temperatures, the chemical properties of the material may change and interact with the sample, furnace gas resulting in failure. This requires consideration of its chemical stability when choosing fire bricks. For example, magnesia refractory bricks can only be used for alkaline slag, while silica bricks can only be used for acidic slag.

Fifth, the bulk density. There is a very large product series for the refractory materials, and different products have different bulk density requirements, so it doesn’t mean the higher the bulk density, the better the product quality. We need to consider its application for the bulk density specification. Nowadays, to reduce heat storage and energy consumption, choosing lightweight insulating refractories and new ceramic fibers can greatly reduce costs.

Refractory Guidance – Informational Links

Refractory Guidance – Informational Links

F.S. Sperry is a refractory contractor. Back in 2013, we began sharing our thoughts and experiences via our blog and email newsletter. We decided that it was time to catch up with many other industries who share information digitally.

We also found that it was helpful to create articles that answer many of the questions we heard on a regular basis regarding materials, installation methods, equipment, cost, etc. This article is a summary of key links to refractory guidance that you might find useful (so you don’t have to sift through the individual blog posts). We’ve grouped these by category.

Feel free to bookmark this page for easy future access. We’ll continue adding links to new articles as we create them. Since many of our jobs are confidential, we can’t provide photos or descriptions, but we are able to talk about our capabilities one-on-one, so reach out to us if you have questions that you don’t see answered here.

Discussions About Refractory Materials

Here we talk about differences in materials and how the equipment and each situation affect the material selection.

Refractory Cost – Lowering and Comparing 

Using inexpensive materials doesn’t always provide the lowest total job cost. Here we provide tips on how to keep your costs under control.

Equipment – Boilers, Furnaces, RTOs and Kilns

Here are checklists for your equipment and case studies of work on specific types of heat processing equipment.

Refractory Installation Methods

Installation methods need to be properly matched to the materials, equipment, downtime and equipment access. Here’s a discussion of each.

General Refractory Guidance and Education

Here are articles about refractories in general and discussions about common misconceptions about refractories.

Evaluating Refractory Contractors

Here are articles about evaluating refractory contractors and their bids for a project.

Examples of F.S. Sperry’s Work

Here are some case studies about our work.

 

 

The key properties of the refractory materials:

 

First of all, we must consider the refractoriness of the fire bricks. Refractoriness refers to the performance of refractory materials against high-temperature actions. Indicates the temperature at which the material softens to a certain degree. The refractoriness must be higher than the actual working temperature. For example, the refractoriness of the fire clay bricks is 1730°C, and its service temperature is 1350°C, the refractoriness of the high alumina bricks is 1790°C, its working temperature is 1430°C.

Secondly, the high-temperature structural strength of the refractories. Refractory fire bricks will withstand a certain pressure during uses, and the structural strength of the material will change under increasing temperatures, so the structural crushing strength is a critical specification for refractory bricks, it basically defines the service temperature of the bricks. This is reflected by its refractoriness under load, and the service temperature of the refractories must be lower than its softening point under load. For example, the refractoriness of the fire clay bricks is 1730°C, and its refractoriness under load is 1350°C, so its highest service temperature is 1350°C.

Third, refractories must have excellent thermal stability. There will be large temperature fluctuations in certain parts of the furnace. For example, when the furnace door is opened, cold air enters. The temperature of the furnace lining drops sharply. This requires the refractory material to have a certain degree of thermal stability to ensure normal operation.

Fourth, refractory materials require high-temperature chemical stability. At high temperatures, the chemical properties of the material may change and interact with the sample, furnace gas resulting in failure. This requires consideration of its chemical stability when choosing fire bricks. For example, magnesia refractory bricks can only be used for alkaline slag, while silica bricks can only be used for acidic slag.

Fifth, the bulk density. There is a very large product series for the refractory materials, and different products have different bulk density requirements, so it doesn’t mean the higher the bulk density, the better the product quality. We need to consider its application for the bulk density specification. Nowadays, to reduce heat storage and energy consumption, choosing lightweight insulating refractories and new ceramic fibers can greatly reduce costs.

If you are looking for more details, kindly visit graphite electrode manufacturer.

Refractory Guidance – Informational Links

Refractory Guidance – Informational Links

F.S. Sperry is a refractory contractor. Back in 2013, we began sharing our thoughts and experiences via our blog and email newsletter. We decided that it was time to catch up with many other industries who share information digitally.

We also found that it was helpful to create articles that answer many of the questions we heard on a regular basis regarding materials, installation methods, equipment, cost, etc. This article is a summary of key links to refractory guidance that you might find useful (so you don’t have to sift through the individual blog posts). We’ve grouped these by category.

Feel free to bookmark this page for easy future access. We’ll continue adding links to new articles as we create them. Since many of our jobs are confidential, we can’t provide photos or descriptions, but we are able to talk about our capabilities one-on-one, so reach out to us if you have questions that you don’t see answered here.

Discussions About Refractory Materials

Here we talk about differences in materials and how the equipment and each situation affect the material selection.

Refractory Cost – Lowering and Comparing 

Using inexpensive materials doesn’t always provide the lowest total job cost. Here we provide tips on how to keep your costs under control.

Equipment – Boilers, Furnaces, RTOs and Kilns

Here are checklists for your equipment and case studies of work on specific types of heat processing equipment.

Refractory Installation Methods

Installation methods need to be properly matched to the materials, equipment, downtime and equipment access. Here’s a discussion of each.

General Refractory Guidance and Education

Here are articles about refractories in general and discussions about common misconceptions about refractories.

Evaluating Refractory Contractors

Here are articles about evaluating refractory contractors and their bids for a project.

Examples of F.S. Sperry’s Work

Here are some case studies about our work.

If you want to learn more, please visit our website graphite electrodes for sale.