Aluminum was first used in quantity for building and construction in the s. The applications were primarily oriented toward decorative detailing and art deco structures. The breakthrough came in , when major structures within the Empire State Building were built with aluminum including interior structures and the famous spire. Today, aluminum is recognized as one of the most energy efficient and sustainable construction materials. The estimated recycled content of aluminum building materials used today is between 50 and 85 percent. The Empire State Building continues to demonstrate the usefulness and value of aluminum as a building construction material.
Dear readers! Our articles talk about typical ways to solve the issue of renting industrial premises, but each case is unique.
If you want to know how to solve your particular problem, please contact the online consultant form on the right or call the numbers on the website. It is fast and free!
Aluminum ExtrusionsVIDEO ON THE TOPIC: 10 Differences Between Aluminum and Stainless Steel
This invention relates in general to radiant burners of fiber matrix composition. The invention relates more particularly to radiant fiber matrix burners for use in applications such as fire tube boilers, process heaters, warm air furnaces, and commerical and residential water heaters. The operating characteristics of conventional fiber matrix burners provide a number of important advantages in gas-fired heating applications.
The burners operate with relatively low NO x emissions, high thermal efficiency, no risk of flashback, they turn on and off instantaneously and operate with little aerodynamic combustion noise. Fiber matrix burners of the type described are capable of being molded into various configurations depending upon the particular end-use application; for example, the burners can be molded into different cylindrical shapes or into flat plate configurations.
The burners have been employed in a wide range of applications including fired heaters such as process heaters in the chemical industry, and for use in the combustion chambers of fire tube boilers, warm air furnaces, and commercial and residential water heaters. The fiber matrix burners have also been adapted for retrofit installation in existing heaters to replace the conventional supported-flame type burners. The operation of conventional fiber matrix burners over a long period of time can result in "aging" of the fiber matrix structure, which reduces burner life.
This "aging" is attributed to the deposit of undesirable crystals of alumina on the surfaces of the fibers such that a gradual build up of the alumina decreases burner activity over time. It is therefore a general object of the present invention to provide a new and improved radiant fiber matrix burner which obviates the "aging" problem of conventional burners. Another object is to provide a fiber matrix composition and method of manufacture which produces a burner that minimizes buildup of undesirable alumina on the fiber surfaces to maintain burner activity over a longer period of time.
The invention in summary comprises a fiber matrix burner and method of manufacture in which the burner element is accreted on a foraminous support from an aqueous slurry comprising ceramic fibers, a binding agent, a vaporizable filler, and a powdered normally non-flammable aluminum alloy.
The burner structure is vacuum formed on a foraminous support of the desired shape. The composition is then heated to vaporize the filler leaving a porous burner structure. The foregoing and additional objects and features of the invention will appear from the following specification in which the several embodiments have been set forth in connection with the accompanying drawings.
In the drawings, FIG. The invention is adapted for a wide range of end-use of applications, such as within the combustion chambers of fire tube boilers, process heaters, warm air furnaces, and commercial and residential water heaters. While the burner 10 shown for the embodiment of FIG.
Burner 10 is comprised of a wall structure 14 formed of a matrix of ceramic fibers, and the wall is carried on a suitable foraminous support, such as the tubular metal screen Interstitial spaces or pores are interconnected throughout the fiber matrix for the passage of gas.
Pre-mixed air and fuel, for example natural gas, is pumped under pressure through inlet 16 and disperses outwardly through the pores of the matrix. The conventional method of manufacturing the above-described prior art burner wall structure includes the preparation of an aqueous slurry of inorganic fibers, binding agent, finely divided filler and powdered aluminum. The inorganic fibers are of ceramic or refractory composition and can be comprised of substantial portions of both alumina and silica with fiber lengths on the order of one inch.
Other fibers that can be employed include quartz fibers, alumina fibers, zirconia fibers, vitreous silica fibers and other generally available ceramic fibers such as the commercially available Kaowool fiber as well as the Fiberfrax ceramic fiber manufactured by the Carborundum Company.
The binding agent used in the conventional process typically comprises a mixture of aluminum nitrate and colloidal alumina in the aqueous slurry. Gels formed from aluminum nitrate and a colloidal aluminum, such as that sold under the name Baymal, are satisfactory for this purpose.
The finely divided filler within the slurry can be of a suitable vaporizable material such as methyl methacrylate, camphor, or menthol.
The next step in the conventional method of manufacture includes accreting the slurry upon a foraminous surface, such as a metal screen, through the application of differential pressure, such as in a vacuum forming process.
The suction force of the vaccuum draws liquid from the slurry through the screen, with the fibers and other solids being retained on the surface of the screen. At this firing temperature the filler material vaporizes, leaving a matrix of uniform, interconnected pores throughout the matrix of fibers.
The burner structure can then be mounted in the combustion chamber or other end-use application for operation.
After initial burner operation the surfaces of the refractory fibers have a thin coating of aluminum oxide and powdered aluminum on the refractory fibers. The aluminum oxide of the coating is formed from the chemical decomposition of the aluminum nitrate, as well as from the colloidal alumina. It is known that in the conventional burners made by the process described the powdered aluminum functions to decrease surface temperature and thereby increase the resistance to thermal flashback, permitting a reasonable range of variation in fuel-air ratio and flow velocity.
During operation of these conventional burners it has been found that a part of the aluminum from the powder vaporizes and forms a layer of gaseous aluminum over the surface of the fibers. This gaseous aluminum tends to deposit on the fiber surfaces and nucleates as alumina crystals. The growth of alumina crystals eventually covers the surface of the fibers and influences the mechanical properties at the surface.
The alumina becomes very brittle such that the surface becomes harder and the matrix less porous. The crystal growth also tends to cover up the surface so that the fuel-air pressure drop rises. All of these factors constitute aging of the burner, which is reflected in decreased burner activity. The present invention forms the fiber matrix burner from a slurry composition which includes the inorganic fibers, binding agent and finely divided filler as in the above-described conventional composition but in which powdered aluminum alloy is employed in place of the powdered aluminum.
Alloys with melting points below that range are undesirable because too much aluminum vapor is formed, and alloys with melting points above that range would not melt, which is desirable for proper operation. Metals suitable for alloying with aluminum for use in the invention include metals selected from the group consisting of copper, zirconium, iron, chromium, silicon, magnesium, zinc and titanium. The aluminum alloy is powdered to an average particle size in the range of 40 to microns, and preferably microns.
The amount of powdered alloy employed in a batch process of making the slurry preferably is in the range of 5 to 80 gm alloy per gallon of binding agent gel, with the range of 30 to 60 gm alloy per gallon of gel producing satisfactory results.
The invention also encompasses powdered aluminum alloyed with two or more metals selected from the group described above, as follows:. Depending on the requirements of a particular end-use application, a suitable catalyst agent, such as metallic Cr, can be interspersed through the matrix as by thin strands of Cr.
An example of manufacturing a fiber matrix burner in accordance with the invention is as follows. The binding agent is mixed in the proportion of The ceramic fiber comprising Kaowool pre-chopped fiber is added in the amount of 18 grams fiber per gallon of gel, with the mixture then agitated. The filler comprising mesh methyl methacrylate is added in the amount of The slurry is then thoroughly agitated. A foraminous support of the desired shape, such as a cylindrical tube of metal screen, is then immersed in the slurry and connected to a source of vacuum.
The vacuum draws the liquids through the openings of the screen to cause accretion of the fibers and other solids onto the outer surface of the screen. This vacuum-forming step continues until the desired burner thickness is achieved, such as within the range of 0.
The burner element can then be mounted in a combustion chamber for connection with a source of pre-mixed fuel and air. During operation of the fiber matrix burner of the invention, the powdered aluminum alloy not only functions to increase resistance to flashback, but markedly extends the burner life in comparison to conventional fiber matrix burners. The aluminum alloy wets the fibers and the wetting increases the aluminum surface area. Surface temperature is decreased and this protects the fibers from extreme temperature, which would degrade fiber life.
The high melting point of the aluminum alloy decreases the amount of aluminum vapor generated at the operating temperatures, and thereby decreases the amount of alumina buildup on the surface.
An equilibrium is achieved between the aluminum vapor in the atmosphere and the aluminum on the fiber surfaces. By decreasing the amount of aluminum vapor concentration in the atmosphere, the present invention decreases the buildup of alumina over time.
The microphotograph of FIG. While the foregoing embodiments are at present considered to be preferred, it is understood that numerous variations and modifications may be made therein by those skilled in the art, and it is intended to cover in the appended claims all such variations and modifications as follows in the true spirit and scope of the invention. OF CA. Effective date : Year of fee payment : 4.
Year of fee payment : 8. Year of fee payment : A fiber matrix burner and method of manufacture in which a shaped burner element is formed by accreting a slurry onto a foraminous support.
After the drying and firing, a porous matrix of the fibers is formed which flamelessly combusts a fuel-air mixture. During combustion, the aluminum alloy inhibits growth of alumina crystals on the fiber surface to prolong burner life and, in addition, protects the burner both from extreme temperature and flashback.
What is claimed is: 1. A burner made by the process of claim 1 in which the powdered aluminum alloy is present in the slurry in the amount of 5 to 80 grams of alloy per gallon of the binding agent gel. A method as in claim 6 in which the powdered aluminum alloy is present in the slurry in the amount of 5 to 80 grams of alloy per gallon of the binding agent gel.
USA en. Method and apparatus for controlling fuel-to-air ratio of the combustible gas supply of a radiant burner. Burner element of woven ceramic fiber, and infrared heater for fluid immersion apparatus including the same.
Chamottewaren-Und Thonofenfabrick Aug. Rath Jun. EPA1 en. Adjunct for improving the bioenergetic properties of mineral building materials. Catalytic oxidation unit comprising a fluid permeable body of fibrous admixture. Additive for ameliorating bio-energetic properties of anorganic and organic products, in particular of mineralic building materials.
Shrink tunnel for shrinking shrink films onto packages, such as boxes, bottles, cans, or similar containers, or packaging units, and a method of operating a shrink tunnel to shrink wrap packages or packaging units.
DEB4 en. Shrink tunnels, shrink gas heaters and shrink-wrap shrink wrap on packages or packages. EPB1 en. JPB2 en. Method for protecting products of oxidation-resistant materials and protected products thereof.
High reducing alumina with a -, cerium oxide - and zirconium oxide base composition, methods for their preparation, and their use in the manufacture of a catalyst. Protective silicon nitride or silicon oxynitride coating for porous refractories. USB1 en. Method to prevent recession loss of silica and silicon-containing materials in combustion gas environments. CAC en. USB2 en. NLC en. Self-cleaning ceramic layers for baking ovens and method for production of self-cleaning ceramic layers.
Electrical heating element, related composites, and composition and method for producing such products using dieless micropyretic synthesis.
Aluminum extrusions are aluminum shapes and products that have been created through the extrusion process. The extrusion process is one of the best ways to uncover the true potential of a piece of aluminum sheet. Extrusion is a dynamic method of manufacturing, and so, all sorts of industries benefit from extrusion technology. Customers value aluminum extrusions in particular for their strength, stability, corrosion resistance and lightness. Read More…. Since , Johnson Brothers has been a leader in the aluminum roll forming industry.
Engineered Products and Forgings
In , the aluminum industry continues to benefit from technical innovations made in alloy development, product-manufacturing technologies, and processing equipment over the last century. The inter-relationships among the alloy development, process innovations, and markets are highlighted. Omitted are details about patent literature or the inception of many technologies; the major criterion for placement on the list was impact on the total industry. Following is an analysis of ten innovations that influenced aluminum production methods and markets. Supplies were limited by difficulties with casting and ingot quality, however.
Aluminum and Aluminum Castings
Account Options Sign in. United States. Economic Joint Committee. Selected pages Page Page Price Trends in SteelConsuming Industries. Meyer Bernstein international affairs director United Steelworkers.
However, it is difficult to refine compared to other metals, such as iron. For this reason, the use of aluminum has lagged behind other metal products while efficient and cost-effective methods were developed to overcome these complexities. There are many similarities between the aluminum and steel industries. The manufacturing processes of both are energy intensive and involve pouring liquid metal into casts or using continuous casting machines. Aluminum and steel also compete in similar markets for the automotive and aerospace industry. However, there are significant differences in the processing and properties of these metals. Bauxite is often covered by several meters of rock and clay, which must first be removed before the bauxite can be recovered. The bauxite then goes through crushing or washing plants before being transported for processing.
Building & Construction
Aluminium Extrusions. We offer structural aluminum framing and stock a full range of profile component products which will complete or help to accessorize your framing solution. This gives the unit high strength as well as simplifying assembly.
Allocation of Scarce Materials for School Construction. United States. Committee on Education and Labor. Statement of Pae. Letters resolutions etc Continued Pa9. Letters resolutions etc Continued p8e. Coostruction under the controlled materials plan Letters resolutions etc submitted for the record by Page.
Technology Innovation in Aluminum Products
Account Options Sign in. My library Help Advanced Book Search. Douglas M. Considine , Glenn D. Advancements in science and engineering have occurred at a surprisingly rapid pace since the release of the seventh edition of this encyclopedia. Large portions of the reference have required comprehensive rewriting and new illustrations.
This invention relates in general to radiant burners of fiber matrix composition. The invention relates more particularly to radiant fiber matrix burners for use in applications such as fire tube boilers, process heaters, warm air furnaces, and commerical and residential water heaters. The operating characteristics of conventional fiber matrix burners provide a number of important advantages in gas-fired heating applications. The burners operate with relatively low NO x emissions, high thermal efficiency, no risk of flashback, they turn on and off instantaneously and operate with little aerodynamic combustion noise. Fiber matrix burners of the type described are capable of being molded into various configurations depending upon the particular end-use application; for example, the burners can be molded into different cylindrical shapes or into flat plate configurations. The burners have been employed in a wide range of applications including fired heaters such as process heaters in the chemical industry, and for use in the combustion chambers of fire tube boilers, warm air furnaces, and commercial and residential water heaters.
United States. Economic Joint Committee. Price Trends in SteelConsuming Industries. Meyer Bernstein international affairs director United Steelworkers.
Examples include microstructures that have defined turbine blade fabrication and optimization over the past half century, including contemporary electron beam melting fabrication of turbine blade alloys and other novel microstructures and architectures, which result from layer by layer, non-equilibrium melt solidification and epitaxial growth involving powder bed laser and electron beam fabrication. Phase transformations and second-phase formation by rapid cooling in metal and alloy components fabricated by laser and electron beam melting technologies are illustrated for a range of high-temperature materials. Using a range of examples, the advantages of fabricating complex especially porous biomedical and related commercial products are described. Prospects for future developments of direct 3D metal and alloy droplet printing, as a key component of the digital factory of the future, are described.
Account Options Sign in. Allocation of Scarce Materials for School Construction. United States. Committee on Education and Labor.
Спросила Николь. - Мы бы хотели, чтобы вы перебрались к нам, в Изумрудный город, - ответил Арчи.