Reasons for firebrick heat burst phenomenon

The reason for firebrick heat burst phenomenon. Do you know the reasons for the phenomenon of heat burst firebrick emerge? Below I explain for your detailed introduction about it:

1, magnesia or magnesia-chrome brick, due to the large thermal expansion coefficient, while also prone to sudden changes in temperature firebrick heat burst.

2, the mineral phase constituted of silica brick, such as quartz, tridymite, cristobalite, due to the temperature change is accompanied by crystal transformation of quartz, along with the volume of mutation, so the heating or cooling brick masonry structure, special Note heat burst problem.

3, insulating firebrick, because of its low thermal conductivity, a large temperature gradient of the brick body, and because of its relatively low intensity, so it is easy to generate heat burst problem.

The above is a brief burst phenomenon firebrick heat reason, I hope for your help, more product information, please feel free to contact us or login inhttp://www.yilongrefractory.com.

Introduction of refractory HCS

The compressive strength of the high temperature refractory material (hot crushing strength, abbreviated HCS) is the maximum pressure of the material at a high temperature higher than 1000-1200 ℃ hot state per unit area can withstand (in units of MPa). Refractory compressive strength generally increases with the increase of temperature changes significantly. With increasing temperature from the room temperature, the intensity decreased linearly. Since then, some materials still continue to decline with increasing temperature; some material when the temperature rises within a certain range, with increasing temperature, and reaches a maximum in accounts under a certain temperature, followed by a sharp decline.

Changes in the compressive strength of high temperature refractory products by certain components of the material, in particular wherein the matrix or binding phase change occurs at a high temperature is controlled. Generally, the crystal is completely composed of sintered refractory material, and due to the high temperature grain boundaries wherein the grains are prone to plastic deformation, especially when its loading rate is small are more likely to plastically deform, so the strength increases with increasing temperature andreduced. Some of the crystal when the melt or at an elevated temperature to form a molten body, such as brick, alumina bricks, and clay, the matrix phase mainly composed of glass, as the temperature increases, the strength of the multiphase material of this was also due microstructure changes with temperature decrease.

When the temperature is further increased, since the viscosity of the glass phase becomes brittle toughness, so that binding between the material particles are more strongly, so that the strength is remarkably improved. Then, as the temperature increases, the melt viscosity of the material due to a sharp decline in the strength of the material also will be a sharp decline.

Refractories for coke oven

Coke oven furnace body structure is what? The use of refractory materials is how? According to the Xinmi Changxing refractories experts, coke oven is thermal equipment dry distillation of coal coke and chemical products, mainly by the carbonization chamber, combustion chamber, top, chute, the regenerator and the small flue etc.. As each part of the main use of refractory material:

(1) Refractory material for carbonization chamber. The carbonization chamber work is periodic, coal furnace wall surface temperature dropped to around 600’C, the end of coking furnace wall surface temperature rose to 1000 to 1100 DEG C. Therefore, the carbonization chamber wall, bottom brick masonry. Furnace head of carbonization chamber at both ends of the opening of the door, because when the temperature suddenly changes, reduced from 10 00’C to 500 DEG C, exceed the temperature limit brick volume stability (573 C), so the furnace head should choose good thermal shock resistance products, most previous selection of clay brick, now tend to use high-quality high aluminum bricks, in selection of sillimanite brick and red brick masonry.

(2) Refractory material for combustion chamber. The combustion chamber and the carbonization chamber shared furnace wall, the bricks with the same carbonization chamber.

(3) Refractories for hot blast furnace. Around the top coal charging hole due to temperature fluctuations, clay brick masonry, other parts of silica bricks masonry.

(4) For refractory material chute. Chute of the combustion chamber is connected with the regenerator, requirements of brick body structure stability, resistance to the action of thermal stress. With the clay brick and small coke oven, large and medium coke using silica brick masonry.

(5) The regenerator refractories. Small coke oven regenerator single wall, partition wall, bottom and checker brick masonry are used for clay brick masonry, storage of large and medium-sized coke oven chamber, the upper masonry all using silica brick masonry, in order to make the whole to the uniform expansion of coke oven.

(6) Refractory material for the small flue. Small flue is located in the bottom of the regenerative chamber communicated with a flue. Small flue with all the clay brick lining.

In general, coke oven refractory materials are mainly siliceous refractory brick. Coke oven silica brick requires accurate size, and have a high enough volume density, thermal conductivity, high temperature creep resistance and high temperature strength of brick; phase composition to tridymite, residual quartz that less is more.

The question of how much the proportion accounted for cement in castable refractory

In the use of castable refractories, cement is added in a certain proportion, if not add the proportion of refractory castable, whole effect will be affected to a certain extent, then to tell you in the cement castable refractory in the percentage of problems:

Using cement as binder for refractory pouring material has the advantages of simple construction, wide application range and so become refractory castable most customers Pro gaze now. Refractory castable cement is the main factor to determine the initial strength of the castable refractory, so many customers that cement castable refractory in the greater proportion of the strength of the castable is better! Now I can clearly tell you: This is not right. Because if the content of cement refractory castables inside is too high, it is easy to cause the reaction in later add end mixture hardening when you need to add a certain amount of water, this will make the castable formation setting and hardening strength when certain, so we can call this kind of castable refractory for hydraulic. But there is one thing we should know is the main point to decide the strength of cement castable refractories, if the volume of cement did not add to or less will cause the strength of the castable is not ideal. But its refractory degree is not very high, so we should pay attention to the use of in room temperature when in use, and may use less cement. But really need to increase the compactness of cement or construction must be used, we can choose the refractory powder doped in to. So we in the pouring material inside when using cement must be careful not to use too much.

Refractory brick grinder designing needs to follow the rules

Refractory brick in the production process cannot do without the help of the size and quality of mold, mold determines the quality of refractory brick molding, the following is the principle of making refractory brick shaping mould:

1, the form must be smooth surface, smooth, and have higher hardness.

2, installation of formwork should taper, under the mouth small, big, catchy symmetry, and to ensure that qualified size refractory brick. Taper model after installation is generally 5/1000.

3, uneven surface should be made into a hopper.

4, as far as possible to make the maximum area of the firebrick as the compression face.

Ditch edge at 5, within the model with radian, template at a corner with L – 2 mm arc.

6, in the event of a mould bottom protruding part, try to make the survival of wedge.

7, the scaling length ratio. The general is according to different kind of brick and clay, is determined by the actual test. At present, China’s production of brick, scaling rate is generally 3-4%; length ratio put clay brick for 1-2.5%.

8, thick skin: refractory brick more than 150 mm, should consider two pressures.

Through the above simple introduction I hope can help to you, we produced the high quality and low price firebrick , please contact us if you have the need.

Refractory application requirements of guard fired boiler

Boiler combustion properties with refractory material should have included slag resistance, high strength, wear resistance, thermal stability, and thermal conductivity higher performance. The traditional ignition belt mainly used chrome refractory ramming material, but because of the high chromium resource scarcity, therefore is the main use of siliconcarbide ramming material, silicon carbide high alumina coating material, high aluminum phosphate can be plastic, plastic high-temperature expansion.

The first two kinds of materials are expensive, but long life, good performance, and then two kinds of material price is low, but performance in general, and short service life. Therefore in the cyclone furnace slag tap furnace and should not be used in high phosphate refractory plastic or ramming material, avoid peeling or cracks in use, so as to improve the slag resistance of material and reduce the repair frequency.

High-temperature micro expansion refractory plastic and super 3000 water clay refractory performance considerably, showing some advantages when applied to a wall pipe and the top of the boiler. But the material in its solidification time is long, easy to dry shrinkage crack, so as to the construction and maintenance of a big trouble. At the same time delivery quality exist certain volatility, sometimes refractoriness and strength at room temperature is below 1580 degrees and 981N/cm2.

Refractory brick inherited what excellent characteristics of refractory clay

Refractory clay is a refractory degree is higher than 1580 degrees Celsius, refractory clay and can be used as refractory bauxite. They except has high refractoriness outside, can maintain volume stability at high temperature, and has the slag resistance, resistance to thermal shock, and certain mechanical strength. Refractory clay calcined abnormal firm, can be made of refractory brick.

Soft clay general is earthy, easily dispersed in water, and the liquid after mixing can form plasticity mud pie; half the baptism of soft clay powder is poor, the leaching of powder and liquid mixing can be formed after plasticity mud pie. The two kinds of clay used as binder in the production of refractory bricks and refractory products.

Hard clay often with a block or plate, generally in the water can not soak powder, refractory degrees higher, and the main raw material for refractory products. High alumina clay Al2O3 content is higher, the hardness and the proportion of large, high refractoriness, used to make advanced clay products.

Refractory clay is mainly used in the metallurgical industry, as the production of  refractory materials (various specifications of the brick wood) and unshaped refractory materials. Refractory clay in building materials industry to make cement kilns and glass melting furnace with high alumina brick, high aluminum phosphate brick, high aluminum casting brick etc… Also has important use in grinding industry, chemical industry and ceramic industry, raw materials can also be used as a manufacturing daily-use ceramics, industrial ceramics and building ceramics.