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Chemical Reactor Materials Selection
Chemical reactor materials selection is an important aspect in the design of a chemical reactor. There are four main groups of chemical reactors - CSTR, PFR, semi-batch, and catalytic - with variations on each. Depending on the nature of the chemicals involved in the reaction, as well as the operating conditions (e.g. temperature and pressure), certain materials will perform better over others. Material Options There are several broad classes of materials available for use in creating a chemical reactor. Some examples include metals, glasses, ceramics, polymers, carbon, and composites.20% chromium for the purpose of forming a protective oxide against further oxidation. There are also various other elements to aid in corrosion resistance such as aluminum, silicon, and rare earth elements such as yttrium, cerium, and lanthanum Lanthanum is a chemical element; it has symbol La and atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Reactor
A chemical reactor is an enclosed volume in which a chemical reaction takes place. In chemical engineering, it is generally understood to be a process vessel used to carry out a chemical reaction, which is one of the classic unit operations in chemical process analysis. The design of a chemical reactor deals with multiple aspects of chemical engineering. Chemical engineers design reactors to maximize net present value for the given reaction. Designers ensure that the reaction proceeds with the highest efficiency towards the desired output product, producing the highest yield (chemistry), yield of product while requiring the least amount of money to purchase and operate. Normal operating expenses include energy input, energy removal, raw material costs, labor, etc. Energy changes can come in the form of heating or cooling, pumping to increase pressure, frictional pressure loss or agitation.Chemical reaction engineering is the branch of chemical engineering which deals with chemical r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brittleness
A material is brittle if, when subjected to stress (physics), stress, it fractures with little elastic deformation and without significant plastic deformation. Brittle materials absorb relatively little energy prior to fracture, even those of high strength of materials, strength. Breaking is often accompanied by a sharp snapping sound. When used in materials science, it is generally applied to materials that fail when there is little or no plasticity (physics), plastic deformation before failure. One proof is to match the broken halves, which should fit exactly since no plastic deformation has occurred. Brittleness in different materials Polymers Mechanical characteristics of polymers can be sensitive to temperature changes near room temperatures. For example, poly(methyl methacrylate) is extremely brittle at temperature 4˚C, but experiences increased ductility with increased temperature. Amorphous polymers are polymers that can behave differently at different temperatures. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerium
Cerium is a chemical element; it has Chemical symbol, symbol Ce and atomic number 58. It is a hardness, soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it often shows the oxidation state of +3 characteristic of the series, it also has a stable +4 state that does not oxidize water. It is considered one of the rare-earth elements. Cerium has no known biological role in humans but is not particularly toxic, except with intense or continued exposure. Despite always occurring in combination with the other rare-earth elements in minerals such as those of the monazite and bastnäsite groups, cerium is easy to extract from its ores, as it can be distinguished among the lanthanides by its unique ability to be oxidized to the +4 state in aqueous solution. It is the most common of the lanthanides, followed by neodymium, lanthanum, and praseodymium. Its estimated abundance of elements in Earth's crust, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yttrium
Yttrium is a chemical element; it has Symbol (chemistry), symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free element. 89Y is the only stable isotope and the only isotope found in the Crust (geology), Earth's crust. The most important present-day use of yttrium is as a component of phosphors, especially those used in LEDs. Historically, it was once widely used in the red phosphors in television set cathode ray tube displays. Yttrium is also used in the production of electrodes, electrolytes, electronic filters, lasers, superconductors, various medical applications, and Trace element, tracing various materials to enhance their properties. Yttrium has no known Biology, biological role. Exposure to yttrium compounds can cause Respiratory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASME Boiler And Pressure Vessel Code (BPVC)
The ASME Boiler & Pressure Vessel Code (BPVC) is an American Society of Mechanical Engineers, American Society of Mechanical Engineers (ASME) standardization, standard that regulates the design and construction of boilers and pressure vessels. The document is written and maintained by volunteers chosen for their technical expertise . The ASME works as an accreditation body and entitles independent third parties (such as verification, testing and certification agencies) to inspect and ensure compliance to the BPVC. History The BPVC was created in response to public outcry after several serious explosions in the state of Massachusetts. A fire-tube boiler exploded at the Grover Shoe Factory disaster, Grover Shoe Factory in Brockton, Massachusetts, on March 20, 1905, which resulted in the deaths of 58 people and injured 150. Then on December 6, 1906, a boiler in the factory of the P.J. Harney Shoe Company exploded in Lynn, Massachusetts. As a result, the state of Massachusetts enacted t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Material Selection
Material selection is a step in the process of designing any physical object. In the context of product design, the main goal of material selection is to minimize cost while meeting product performance goals. Systematic selection of the best material for a given application begins with list of materials properties, properties and costs of candidate materials. Material selection is often benefited by the use of material index or performance index relevant to the desired material properties. For example, a thermal blanket must have poor thermal conductivity in order to minimize heat transfer for a given temperature difference. It is essential that a designer should have a thorough knowledge of the properties of the materials and their behavior under working conditions. Some of the important characteristics of materials are : strength, durability, flexibility, weight, resistance to heat and corrosion, ability to cast, welded or hardened, machinability, electrical conductivity, etc. In c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Material
A composite or composite material (also composition material) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a material with properties unlike the individual elements. Within the finished structure, the individual elements remain separate and distinct, distinguishing composites from mixtures and solid solutions. Composite materials with more than one distinct layer are called ''composite laminates''. Typical engineered composite materials are made up of a binding agent forming the ''matrix'' and a Filler (materials), filler material (particulates or fibres) giving ''substance'', e.g.: * Concrete, reinforced concrete and masonry with cement, lime or Mortar (masonry), mortar (which is itself a composite material) as a binder * Composite wood such as glulam and plywood with wood glue as a binder * Reinforced plastics, such as fiberglass and fibre-rein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compound (chemistry), compounds, produces unique physical property, physical properties including toughness, high rubber elasticity, elasticity, viscoelasticity, and a tendency to form Amorphous solid, amorphous and crystallization of polymers, semicrystalline structures rath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceramic Engineering
Ceramic engineering is the science and technology of creating objects from inorganic, non-metallic materials. This is done either by the action of heat, or at lower temperatures using precipitation reactions from high-purity chemical solutions. The term includes the purification of raw materials, the study and production of the chemical compounds concerned, their formation into components and the study of their structure, composition and properties. Ceramic materials may have a crystalline or partly crystalline structure, with long-range order on atomic scale. Glass-ceramics may have an amorphous or glassy structure, with limited or short-range atomic order. They are either formed from a molten mass that solidifies on cooling, formed and matured by the action of heat, or chemically synthesized at low temperatures using, for example, hydrothermal or sol-gel synthesis. The special character of ceramic materials gives rise to many applications in materials engineering, electri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuous Stirred-tank Reactor
The continuous stirred-tank reactor (CSTR), also known as vat- or backmix reactor, mixed flow reactor (MFR), or a continuous-flow stirred-tank reactor (CFSTR), is a common model for a chemical reactor in chemical engineering and environmental engineering. A CSTR often refers to a model used to estimate the key unit operation variables when using a continuous agitated-tank reactor to reach a specified output. The mathematical model works for all fluids: liquids, gases, and slurries. The behavior of a CSTR is often approximated or modeled by that of an ideal CSTR, which assumes perfect mixing. In a perfectly mixed reactor, reagent is instantaneously and uniformly mixed throughout the reactor upon entry. Consequently, the output composition is identical to composition of the material inside the reactor, which is a function of residence time and reaction rate. The CSTR is the ideal limit of complete mixing in reactor design, which is the complete opposite of a plug flow reactor (P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass
Glass is an amorphous (non-crystalline solid, non-crystalline) solid. Because it is often transparency and translucency, transparent and chemically inert, glass has found widespread practical, technological, and decorative use in window panes, tableware, and optics. Some common objects made of glass are named after the material, e.g., a Tumbler (glass), "glass" for drinking, "glasses" for vision correction, and a "magnifying glass". Glass is most often formed by rapid cooling (quenching) of the Melting, molten form. Some glasses such as volcanic glass are naturally occurring, and obsidian has been used to make arrowheads and knives since the Stone Age. Archaeological evidence suggests glassmaking dates back to at least 3600 BC in Mesopotamia, Ancient Egypt, Egypt, or Syria. The earliest known glass objects were beads, perhaps created accidentally during metalworking or the production of faience, which is a form of pottery using lead glazes. Due to its ease of formability int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fracture
Fracture is the appearance of a crack or complete separation of an object or material into two or more pieces under the action of stress (mechanics), stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displacement develops perpendicular to the surface, it is called a normal tensile crack or simply a crack; if a displacement develops tangentially, it is called a shear crack, slip band, or dislocation. #Brittle, Brittle fractures occur without any apparent deformation before fracture. #Ductile, Ductile fractures occur after visible deformation. Fracture strength, or breaking strength, is the stress when a specimen fails or fractures. The detailed understanding of how a fracture occurs and develops in materials is the object of fracture mechanics. Strength Fracture strength, also known as breaking strength, is the stress at which a specimen structural integrity and failure, fails via fra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
