Papers Category:Engineering Papers
- Materials Engineering Papers
Post Time:2011-11-24 10:45:00
Abstract: This paper introduces the production process within the wall blank formulation, slurry parameters, molding, biscuit firing, glaze firing, glaze and other factors on the Arts and six rapid firing of the product, emphasizing the improvement of technology to promote the product of rapid firing, and further demonstrates the rapid firing of the importance of environmental health section.
Paper Keywords: wall, rapid firing; green energy
0 Introduction As the world's industrial economy, the rapid increase in population, rising and unlimited human desire uncontrolled production and lifestyle.
The world is facing increasingly serious climate problems, increasing carbon dioxide emissions, global catastrophic climate change are often seen. Has been serious harm to human health and safety of living environment and the end of .2009. Copenhagen Climate Change Conference held in low power consumption, low emission, low-carbon economy increasingly marked by the consensus of all mankind. Similarly, today's ceramic companies should face the challenge of global climate issues, while efforts have been made by Kai, the use of advanced production technology to achieve the purpose of energy saving.'s Rapid firing within the wall is now a widely used ceramic enterprises kinds of production processes, one can reduce energy consumption, improve economic efficiency of enterprises, on the other hand to achieve environmental and social benefits. With the development of the industry, more and more attention ceramic enterprises to improve production technology, improve production efficiency, to achieve further energy-saving environmental protection .
A rapid firing blank formulation
(1) raw material selection principles to maximize the amount of barren material to minimize the firing shrinkage, organic content, as well as the amount of clay and carbonate, the premise is to ensure that green strength so the product can reduce the deformation rate is conducive to rapid firing process. (2) the choice of clay as far as possible use plastic, a small loss on ignition, a good raw material for plastic solution.
This can reduce the amount of clay if necessary choose an alumina clay to balance SiO2/Al2O3. Control the flatness, low aluminum content is easy to make green body deformation in the firing process defects, AI20 content of the best control in 18% -21%. (3) the choice of fast-burning materials.
May introduce some pyrophyllite, diopside and wollastonite and other chain, needle-like structure of the material, which is characterized by a small loss on ignition of linear shrinkage and the shrinkage is small, fast heat conduction, firing temperature low, especially suitable for fast firing process requirements. (4) auxiliary flux material selection.
In addition to diopside and wollastonite, but also can introduce some limestone. Limestone are burned as a rejection of anti-inflation can reduce the contraction of the green body. (5) of potassium and sodium content of clay in general is enough, if necessary, to introduce a small amount of feldspar of raw materials. (6) The formula for example.
Formula is reflected in the fast burn easily oxidized, easy to humidity, heat and fast, easy to dry and crack. Billet blow drying, low firing temperature. Examples of various formulations of mineral composition range shown in Table 1 - Table 3 (recipe taken from the Universal Plant Minqing data).
2 mud Parameters
To ensure proper thixotropic slurry, suspension is good, water as low as possible, liquidity as well as possible, usually B = 3 ~ 5, the proportion of 1.6 ~ 1.8g/ear between mud, mud a 250 mesh stiffness 6% 8% sieve, and make mud iron work powder over l2 ~ 14 mesh to fine some good. In short.
Formulation types of raw materials as much as possible, so that a material change does not affect too much, increasing the stability of formulations to improve the stability of the product formulation is composed of roughly 40% -50% clay, 50% of barren material a 6O%, pyrophyllite can be viewed as a barren material.
3 forming Molding pressure to ensure the green strength of the case as small as possible.
And double-sided pressure. This is conducive to drying and oxidation of the exhaust.
Kiln width 2.95m, unglazed cycle 33 ~ 35min, each minute into eight, gas for the cold gas, drying 6-7min, structure upper and lower heat and humidity separately, which improves drying efficiency, not to avoid drying up and down are, appear dry and cracked, while avoiding the hot air convection from the furnace up and down both sides, leading edge dry and cracked two brick kilns can be set to block the middle of the fire board and block firewall. Dominated the first half of the flue gas heat, heat the latter part of the main kiln heat, add enough hot gas can be achieved through the smoke and heat control, respectively, the first part of positive pressure drying, the temperature-based, row wet, giving the moisture that allows part of the drying kiln dried again back to people, to ensure that the kiln humidity to warrant the surface is dry too quickly, leading to dry and crack. for the latter part of the negative pressure humidity. this structure, high efficiency, dry less than 1% residual moisture, temperature section does not fry to ensure billet.
For the wide-body kiln, each section of the kiln length is shorter, the density can be increased burner, to ensure for the heat, about every section of 1.8m, fully oxidized oxidation stage, high-temperature section of deformation. Unglazed appropriate higher temperature, the reaction completely certain, to minimize oxidation of the glaze kiln exhaust to avoid glaze bubbles and pinholes. To reduce the glaze firing kiln sintering the green body reaction, to avoid deformation of glaze firing, glaze firing will help speed .. Links to free download http://eng.hi138.com
Quench cooling section and pumping hot air is the best automatic frequency control. Empty kiln to reduce the wind split. Fast firing is reflected in the rapid and efficient drying, oxidation, cooling of the furnace utilization.
(1) end of the glaze, if you do not consider the flooding, then appropriate to reduce the sintering degree, this firing range, which will help to reduce chromatic aberration. Fineness number, 325 mesh sieve 1% o ~ 2% o.
(2) CMC, STPP use of good quality. Kaolin reconciliation to ensure that sticky glue performance, short end of the glaze firing have wide range viscosity and low thixotropic good, reasonable moisture, so that can promote billet and the bottom with the glaze of the question, is not easy to peel glaze, the glaze is not easy to pour from the hole, not easy to produce color.
(3) surface glaze, have a high melting point of beginning, the appropriate fineness thicker, good leveling high temperatures, good drainage performance, wide firing range, good thermal stability, so that can guarantee fast firing and will not a pinhole, glaze bubbles, as a result of poor drainage caused the gloss is not good and pinholes, orange peel and post-cracking. enamel surface before rapid firing reflected in the high melting point (put the appropriate thickness can improve the degree of surface enamel before melting point, increase the exhaust resistance), good high-temperature fast leveling, drainage and quick drying areas.
(4), glaze, ink 250 to be able to head all through, glaze over 250 mesh sieve and good lubricity, reduce dip net, good suspension and corrosion resistance, good moisture retention. Reduce the drying time reduction glaze glaze firing can lead to poor drainage and poor gloss glaze pinholes. To strengthen the drying effect, if necessary, about one-thousandth of the glaze by adding urea. Can greatly accelerate the drainage process. Fast glaze firing is reflected in the rapid drying without reduction glaze.
6 glaze firing Cycle 31 ~ 33min.
Kiln width 2.65m, per minute into the 7 and less into a cross-section helps to reduce temperature, to avoid chromatic aberration. Burner set far forward as possible, to extend the oxidation section, can be glazed to avoid air bubbles, pinholes, but also avoid the distortion caused by the back warming up too fast. Cooling process and the process of cooling the same unglazed.
7 rapid firing limitations in production Although the rapid firing within the wall to improve production efficiency, to promote green energy has its advantages.
However, its limitations should also be factors to consider and face, mainly in the following areas: (1) the choice of material has its limitations.
And compared to normal firing. Fast firing more stringent requirements on raw materials. Thus, virtually increases the cost of the product: Also, some material is not very easy to find. (2) process difficult to control nature.
Slurry performance to stabilize, after spray granulation formulations to ensure the stability of stock. May reduce the deformation of the product. After the spray granulation of the powder are consistent with hard water, particle size distribution is difficult by the ideal preparation, leading to rapid firing deformation requirements of the fuel in the furnace (gas or oil) as a pure, high calorific value and uniform heat, as small as possible to ensure the furnace temperature, and firing mainly by manual control and more non-mechanical automatic control.
The rapid firing within the wall is the current promotion of a ceramic enterprises increasingly technology fast firing ceramic enterprise development and to comply with their enormous economic benefits of ceramic technology companies in the fast firing for them to enjoy the benefits of both. Also responds to the national release on environment protection and energy policy. Rapid firing of ceramics will increasingly be more acceptable to business, so reasonable in the optimization process (the process parameters for each business are different), as will be conducive to fast Shao Shao, enterprises will be more conducive to energy saving . Links to free download http://eng.