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Liquid-to-gas Ratio
An important parameter in wet scrubbing systems is the rate of liquid flow. It is common in wet scrubber terminology to express the liquid flow as a function of the gas flow rate that is being treated. This is commonly called the liquid-to-gas ratio (L/G ratio) and uses the units of gallons per 1,000 actual cubic feet or litres per cubic metre (L/m3). Expressing the amount of liquid used as a ratio enables systems of different sizes to be readily compared. For particulate removal, the liquid-to-gas ratio is a function of the mechanical design of the system; while for gas absorption this ratio gives an indication of the difficulty of removing a pollutant. Most wet scrubbers used for particulate control operate with liquid-to-gas ratios in the range of 4 to 20 gallons per 1,000 actual cubic foot (0.5 to 3 litres per actual cubic metre). Depending on scrubber design, a minimum volume of liquid is required to "wet" the scrubber internals and create sufficient collection targets. After ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scrubber
Scrubber systems (e.g. chemical scrubbers, gas scrubbers) are a diverse group of air pollution control devices that can be used to remove some particulates and/or gases from industrial exhaust streams. An early application of a carbon dioxide scrubber was in the submarine the ''Ictíneo I'', in 1859; a role for which they continue to be used today. Traditionally, the term "scrubber" has referred to pollution control devices that use liquid to wash unwanted pollutants from a gas stream. Recently, the term has also been used to describe systems that inject a dry reagent or slurry into a dirty exhaust stream to "wash out" acid gases. Scrubbers are one of the primary devices that control gaseous emissions, especially acid gases. Scrubbers can also be used for heat recovery from hot gases by flue-gas condensation.On Flue gas Condensa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particulate
Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The term ''aerosol'' commonly refers to the particulate/air mixture, as opposed to the particulate matter alone. Sources of particulate matter can be natural or anthropogenic. They have impacts on climate and precipitation that adversely affect human health, in ways additional to direct inhalation. Types of atmospheric particles include suspended particulate matter; thoracic and respirable particles; inhalable coarse particles, designated PM, which are coarse particles with a diameter of 10 micrometers (μm) or less; fine particles, designated PM, with a diameter of 2.5 μm or less; ultrafine particles, with a diameter of 100 nm or less; and soot. The IARC and WHO designate airborne particulates as a Group 1 carcinogen. Particulates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollutant
A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oil) or anthropogenic in origin (i.e. manufactured materials or byproducts from biodegradation). Pollutants result in environmental pollution or become public health concerns when they reach a concentration high enough to have significant negative impacts. A pollutant may cause long- or short-term damage by changing the growth rate of plant or animal species, or by interfering with human amenities, comfort, health, or property values. Some pollutants are biodegradable and therefore will not persist in the environment in the long term. However, the degradation products of some pollutants are themselves polluting such as the products DDE and DDD produced from the degradation of DDT. Pollution has widespread negative impacts on the enviro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure Drop
Pressure drop is defined as the difference in total pressure between two points of a fluid carrying network. A pressure drop occurs when frictional forces, caused by the resistance to flow, act on a fluid as it flows through the tube. The main determinants of resistance to fluid flow are fluid velocity through the pipe and fluid viscosity. Pressure drop increases proportionally to the frictional shear forces within the piping network. A piping network containing a high relative roughness rating as well as many pipe fittings and joints, tube convergence, divergence, turns, surface roughness, and other physical properties will affect the pressure drop. High flow velocities and/or high fluid viscosities result in a larger pressure drop across a section of pipe or a valve or elbow. Low velocity will result in lower or no pressure drop. The fluid may also be biphasic as in pneumatic conveying with a gas and a solid, in this case, the friction of the solid must also be taken into consi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flue-gas Desulfurization
Flue-gas desulfurization (FGD) is a set of technologies used to remove sulfur dioxide () from exhaust flue gases of fossil-fuel power plants, and from the emissions of other sulfur oxide emitting processes such as waste incineration. Methods Since stringent environmental regulations limiting emissions have been enacted in many countries, is being removed from flue gases by a variety of methods. Common methods used: * Wet scrubbing using a slurry of alkaline sorbent, usually limestone or lime, or seawater to scrub gases; * Spray-dry scrubbing using similar sorbent slurries; *Wet sulfuric acid process recovering sulfur in the form of commercial quality sulfuric acid; * SNOX Flue gas desulfurization removes sulfur dioxide, nitrogen oxides and particulates from flue gases; *Dry sorbent injection systems that introduce powdered hydrated lime (or other sorbent material) into exhaust ducts to eliminate and from process emissions. For a typical coal-fired power station, flue-ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venturi Scrubber
A venturi scrubber is designed to effectively use the energy from a high-velocity inlet gas stream to atomize the liquid being used to scrub the gas stream. This type of technology is a part of the group of air pollution controls collectively referred to as wet scrubbers. Venturis can be used to collect both particulate and gaseous pollutants, but although the liquid surface area provided is quite large they are more effective in removing particles since particles can be trapped by contact, but gases must be trapped by absorption during the relatively short exposure time. Venturi devices have also been used for over 100 years to measure fluid flow ( Venturi tubes derived their name from Giovanni Battista Venturi, an Italian physicist). In the late 1940s, H.F. Johnstone'','' William Jones, and other researchers found that they could effectively use the venturi configuration to remove particles from gas streams. Figure 1 illustrates the classic venturi configuration. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spray Tower
A spray tower (or spray column or spray chamber) is gas-liquid contactor used to achieve mass and heat transfer between a continuous gas phase (that can contain dispersed solid particles) and a dispersed liquid phase. It consists of an empty cylindrical vessel made of steel or plastic, and nozzles that spray liquid into the vessel. The inlet gas stream usually enters at the bottom of the tower and moves upward, while the liquid is sprayed downward from one or more levels. This flow of inlet gas and liquid in opposite directions is called countercurrent flow. Overview This type of technology can be used for example as a wet scrubber for air pollution control. Countercurrent flow exposes the outlet gas with the lowest pollutant concentration to the freshest scrubbing liquid. Many nozzles are placed across the tower at different heights to spray all of the gas as it moves up through the tower. The reason for using many nozzles is to maximize the number of fine droplets impacting th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moving Bed Scrubber
Moving or Movin' may refer to: Moving of goods * Relocation (personal), the process of leaving one dwelling and settling in another * Relocation of professional sports teams * Relocation (computer science) * Structure relocation Music Albums * ''Moving'' (Peter, Paul and Mary album), 1963 * ''Moving'' (The Raincoats album), 1983 * ''Movin (Herman van Doorn album), 2001 * ''Movin (Jennifer Rush album), 1985 Songs * "Moving" (Kate Bush song), 1978 * "Moving" (Supergrass song), 1999 * "Moving" (Travis song), 2013 * "Moving", by Suede from ''Suede'', 1993 * "Moving", by Cathy Davey from ''Tales of Silversleeve'', 2007 * "Movin (Brass Construction song), 1976 * "Movin (Mohombi song), 2014 * "Movin, by Skin from ''Fake Chemical State'', 2006 Other uses * ''Moving'' (1988 film), a comedy starring Richard Pryor * ''Moving'' (1993 film), a Japanese film * ''Moving'' (British TV series), a British sitcom starring Penelope Keith *Moving (South Korean TV series), an up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absorption (chemistry)
In chemistry, absorption is a physical or chemical phenomenon or a process in which atoms, molecules or ions enter some bulk phase – liquid or solid material. This is a different process from adsorption, since molecules undergoing absorption are taken up by the volume, not by the surface (as in the case for adsorption). A more common definition is that "Absorption is a chemical or physical phenomenon in which the molecules, atoms and ions of the substance getting absorbed enters into the bulk phase (gas, liquid or solid) of the material in which it is taken up." A more general term is ''sorption'', which covers absorption, adsorption, and ion exchange. Absorption is a condition in which something takes in another substance. In many processes important in technology, the chemical absorption is used in place of the physical process, e.g., absorption of carbon dioxide by sodium hydroxide – such acid-base processes do not follow the Nernst partition law (see: solubility). For ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solubility
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solubility of a substance in a specific solvent is generally measured as the concentration of the solute in a saturated solution, one in which no more solute can be dissolved. At this point, the two substances are said to be at the solubility equilibrium. For some solutes and solvents, there may be no such limit, in which case the two substances are said to be " miscible in all proportions" (or just "miscible"). The solute can be a solid, a liquid, or a gas, while the solvent is usually solid or liquid. Both may be pure substances, or may themselves be solutions. Gases are always miscible in all proportions, except in very extreme situations,J. de Swaan Arons and G. A. M. Diepen (1966): "Gas—Gas Equilibria". ''Journal of Chemical Physics'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expansion Ratio
The expansion ratio of a liquefied and cryogenic substance is the volume of a given amount of that substance in liquid form compared to the volume of the same amount of substance in gaseous form, at room temperature and normal atmospheric pressure. If a sufficient amount of liquid is vaporized within a closed container, it produces pressures that can rupture the pressure vessel. Hence the use of pressure relief valves and vent valves are important. The expansion ratio of liquefied and cryogenic from the boiling point to ambient is: *nitrogen – 1 to 696 *liquid helium – 1 to 745 *argon – 1 to 842 *liquid hydrogen – 1 to 850 *liquid oxygen – 1 to 860 * neon – Neon has the highest expansion ratio with 1 to 1445. See also *Liquid-to-gas ratio *Boiling liquid expanding vapor explosion *Thermal expansion Thermal expansion is the tendency of matter to change its shape, area, volume, and density in response to a change in temperature, usually not including phase t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Separation Processes
A separation process is a method that converts a mixture or a solution of chemical substances into two or more distinct product mixtures, a scientific process of separating two or more substance in order to obtain purity. At least one product mixture from the separation is enriched in one or more of the source mixture's constituents. In some cases, a separation may fully divide the mixture into pure constituents. Separations exploit differences in chemical properties or physical properties (such as size, shape, mass, density, or chemical affinity) between the constituents of a mixture. Processes are often classified according to the particular properties they exploit to achieve separation. If no single difference can be used to accomplish the desired separation, multiple operations can often be combined to achieve the desired end. With a few exceptions, elements or compounds exist in nature in an impure state. Often these raw materials must go through a separation before th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
