Energy saving and function of Aluminium silicate ceramic fiber
Aluminium silicate fiber, also known as ceramic fiber, has a growing application prospect in high-temperature firing kilns. Refractory felt and blanket products made of Aluminium silicate fiber can reach 1430 ℃ at a higher temperature. It is widely accepted in various kilns due to its good insulation performance, easy use, and small heat storage, greatly demonstrating high energy efficiency.
The objective of Aluminium silicate refractory fiber is its diameter and thermal stability. Al2O3 and SiO2 fibers are commonly used in Aluminium silicate industry. According to the content of Al2O3, there are different utilization ranges. Cr2O3 material is also introduced to improve its fire resistance and oxidation resistance. Fiber products with high alumina content and low impurity content such as iron oxide are usually pure white, while fibers introduced with chromium oxide have a milky yellow color. The average diameter of Aluminium silicate fiber is 22-33 microns. Those with fine fibers, low density, and low thermal conductivity have higher utilization temperature. If the fiber is thick and dense, the utilization result is not ideal. The thermal stability target of fibers is more important. The linear shrinkage range of various products of Al2O3-SiO2 fibers at 1260 ℃ is between 35-88%. Shrinkage also indirectly affects thermal stability.
fabricated assembly is inclined to be parallel to the heat flow, the difference between the thermal co1、 Variety and performance
Due to the low thermal conductivity, small density and light weight of fiber, light steel frame is adopted to support the layout when making kilns, so that the growth of Aluminium silicate kilns enters the period of “kiln lightweight”. Fiber has small heat storage and is suitable for rapid heating, cooling, and firing methods. The fiber is flexible and can be processed into products with grooves or teeth, and has good resistance to mechanical shock and impact, and has good chemical stability. These advantages have a strong driving force for the growth of new kilns, and the growth of Aluminium silicate technology and industry.
3、 Prospects for growth prospects
Loose fibers can be classified into two types: those with or without lubricant; Long and short fibers mixed together, etc. Several fibers can also be mixed and utilized. Uncleaned fibers are cheaper and can be used as fillers for filling joints. The fiber products added with lubricants are easy to operate and have low dust. Although the dust scattered into the atmosphere during fiber placement is not very toxic, it can cause skin itching or sore throat, so careful protection should be taken during construction.
2、 Masonry essentials and meticulous work
Refractory fiber felt, suitable for kiln lining, can greatly improve energy efficiency. Usually, inorganic adhesives are used to break down fiber rolls into cylindrical or sheet shaped fabrics. After the internal wall of the kiln is built with high temperature light Fire brick, it can be pasted into a lining with Aluminium silicate fiber refractory felt. After firing, the fiber felt or board forms a relatively rigid and has satisfactory rejuvenation ability, and can bounce back to make the joints tight when cooling.
Masonry fiber usually has two main points: one is to lay the felt one layer at a time, and then rivet it with a bolt rod. Usually, temperature resistant metal bolt rods are accepted below 1222 ℃, and aluminum silicate riveting pieces are accepted above 1223 ℃. Fill one end of the hot surface with loose fibers and heat-resistant cement. Acceptance of aluminosilicate riveted parts can also prevent fiber degeneration caused by carbon deposition. The second key is to accept prefabricated components, that is, prefabricated components stacked with blankets or Accordion type prefabricated components folded with 305mm wide blankets. Compared to the two, the latter has higher energy-saving efficiency but higher cost due to the use of dissimilar materials from the furnace shell to the hot surface.
When the temperature decreases, the joints formed by the masonry of fiber prefabricated components need to be embedded with stretchable fibers. The use of prefabricated components is convenient, agile, and easy to maintain, requiring the replacement of damaged parts.
At present, Aluminium silicate fiber products include: felt, blanket, block, bulk fiber, fiber paper and vacuum formed products. The working range is usually 871-1430 ℃. Under special circumstances, it can be used at high temperatures above the limit temperature for a short time.
In terms of thermal efficiency, the layer by layer application method is significantly better than the prefabricated composite component. Because the fiber of the former is inclined to be perpendicular to the heat flow, and the fiber of the stacked prenductivity of the two is about 20-40%. For example, the Accordion shaped folded prefabricated assembly is between the two, and its fiber is inclined to be both parallel and vertical to the heat flow.
As the cost of power continues to fall, the cost of fuel will become the bottleneck to curb the growth of aluminum silicate industry, and energy conservation will become increasingly strained. People are more and more concerned about the heat loss of kilns. Some indirectly paste a layer of refractory Aluminium silicate fiber on the surface of the original refractory lining to improve the thermal efficiency. Before adding, obvious cracks or peeling areas on the kiln wall must be repaired. However, thermal insulation Fire brick and refractory fiber should not be abused arbitrarily. So far, lining materials such as alkaline oxygen blowing steelmaking furnaces and cement reverse rotary kilns have been temporarily unable to use fibers as lining due to high temperature chemical erosion.
For continuous heating equipment such as Aluminium silicate tunnel kiln, refractory Aluminium silicate fiber has already been accepted as the lining of continuous heating equipment. According to relevant material reports, the energy-saving results of refractory Aluminium silicate fiber in rapid push plate kiln and tunnel kiln are obvious. Especially for ultra-high temperature heating, such as in kilns with firing temperatures ranging from 1538 ℃ to 1649 ℃, the acceptance of refractory fibers has better energy-saving results.