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Demister (vapor)
A demister is a device often fitted to vapor–liquid separator vessels to enhance the removal of liquid droplets entrained in a vapor stream. Demisters may be a mesh-type coalescer, vane pack or other structure intended to aggregate the mist into droplets that are heavy enough to separate from the vapor stream. Demisters can reduce the residence time required to separate a given liquid droplet size by reducing the volume and associated cost of separator equipment. Demisters are often used where vapor quality is important in regard to entrained liquids, particularly where separator equipment costs are high (e.g., high-pressure systems) or where space or weight savings are advantageous. For example, in the process of brine desalination on marine vessels, brine is flash-heated into vapor. In flashing, vapor carries over droplets of brine, which have to be separated before condensing, otherwise the distillate vapor would be contaminated with salt. This is the role of the demist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vapor–liquid Separator
In chemical engineering, a vapor–liquid separator is a device used to separate a vapor–liquid mixture into its constituent phases. It can be a vertical or horizontal vessel, and can act as a 2-phase or 3-phase separator. A vapor–liquid separator may also be referred to as a ''flash drum'', ''breakpot'', ''knock-out drum'' or ''knock-out pot'', ''compressor suction drum, suction scrubber'' or ''compressor inlet drum,'' or ''vent scrubber.'' When used to remove suspended water droplets from streams of air, it is often called a demister. Method of operation In vapor-liquid separators gravity is utilized to cause the denser fluid (liquid) to settle to the bottom of the vessel where it is withdrawn, less dense fluid (vapor) is withdrawn from the top of the vessel. In low gravity environments such as a space station, a common liquid separator will not function because gravity is not usable as a separation mechanism. In this case, centrifugal force needs to be utilised in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entrainment (engineering)
In engineering, entrainment is the entrapment of one substance by another substance. For example: * The entrapment of liquid droplets or solid Solid is a state of matter where molecules are closely packed and can not slide past each other. Solids resist compression, expansion, or external forces that would alter its shape, with the degree to which they are resisted dependent upon the ... particulates in a flowing gas, as with smoke. * The entrapment of gas bubbles or solid particulates in a flowing liquid, as with aeration. * Given two mutually insoluble liquids, the emulsion of droplets of one liquid into the other liquid, as with margarine. * Given two gases, the entrapment of one gas into the other gas. * " Air entrainment" – The intentional entrapment of air bubbles into concrete. * Entrainment defect in metallurgy, as a result of folded pockets of oxide inside the melt. See also * Souders–Brown equation References Chemical engineering {{engineerin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coalescer
A coalescer is a device which induces coalescence in a medium. They are primarily used to separate emulsions into their components via various processes, operating in reverse to an emulsifier. Coalescers are of two main types: mechanical and electrostatic. Mechanical coalescers use filters or baffles to make droplets coalesce, while electrostatic coalescers use DC or AC electric fields (or combinations). Mechanical coalescers Mechanical coalescers, which are the more common type of coalescers, operate by physically altering a droplet by ''mechanical'' means. They are commonly applied in the global oil and gas industries for the removal of water or hydrocarbon condensate. While coalescers by definition function as a separation tool for liquids, they are also used, and mistakenly referred to, as filters. In the area of compressed air purification, coalescing filters are used to separate liquid water and oil from compressed air using a coalescing effect. Coalescence (physics) shows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vapor Quality
In thermodynamics, vapor quality is the mass fraction in a saturated mixture that is vapor; in other words, saturated vapor has a "quality" of 100%, and saturated liquid has a "quality" of 0%. Vapor quality is an intensive property which can be used in conjunction with other independent intensive properties to specify the thermodynamic state of the working fluid of a thermodynamic system. It has no meaning for substances which are not saturated mixtures (for example, compressed liquids or superheated fluids). Vapor quality is an important quantity during the adiabatic expansion step in various thermodynamic cycles (like Organic Rankine cycle, Rankine cycle, etc.). Working fluids can be classified by using the appearance of droplets in the vapor during the expansion step. Quality can be calculated by dividing the mass of the vapor by the mass of the total mixture: \chi = \frac where indicates mass. Another definition used in chemical engineering defines quality () o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brine
Brine (or briny water) is a high-concentration solution of salt (typically sodium chloride or calcium chloride) in water. In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of that of solutions used for brining foods) up to about 26% (a typical saturated solution, depending on temperature). Brine forms naturally due to evaporation of ground saline water but it is also generated in the mining of sodium chloride. Brine is used for food processing and cooking (pickling and brining), for de-icing of roads and other structures, and in a number of technological processes. It is also a by-product of many industrial processes, such as desalination, so it requires wastewater treatment for proper disposal or further utilization (fresh water recovery). In nature Brines are produced in multiple ways in nature. Modification of seawater via evaporation results in the concentration of salts in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Desalination
Desalination is a process that removes mineral components from saline water. More generally, desalination is the removal of salts and minerals from a substance. One example is soil desalination. This is important for agriculture. It is possible to desalinate saltwater, especially sea water, to produce water for human consumption or irrigation. The by-product of the desalination process is brine. Many seagoing ships and submarines use desalination. Modern interest in desalination mostly focuses on cost-effective provision of fresh water for human use. Along with recycled wastewater, it is one of the few water resources independent of rainfall. Due to its energy consumption, desalinating sea water is generally more costly than fresh water from surface water or groundwater, water recycling and water conservation; however, these alternatives are not always available and depletion of reserves is a critical problem worldwide. Desalination processes are using either thermal methods (i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash Evaporation
Flash evaporation (or partial evaporation) is the partial vapor that occurs when a saturated liquid stream undergoes a reduction in pressure by passing through a throttling valve or other throttling device. This process is one of the simplest unit operations. If the throttling valve or device is located at the entry into a pressure vessel so that the flash evaporation occurs within the vessel, then the vessel is often referred to as a flash drum. If the saturated liquid is a single-component liquid (for example, propane or liquid ammonia), a part of the liquid immediately "flashes" into vapor. Both the vapor and the residual liquid are cooled to the saturation temperature of the liquid at the reduced pressure. This is often referred to as "auto-refrigeration" and is the basis of most conventional vapor compression refrigeration systems. If the saturated liquid is a multi-component liquid (for example, a mixture of propane, isobutane and normal butane), the flashed vapor i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distillate
Distillation, also classical distillation, is the process of separating the component substances of a liquid mixture of two or more chemically discrete substances; the separation process is realized by way of the selective boiling of the mixture and the condensation of the vapors in a still. Distillation can operate over a wide range of pressures from 0.14 bar (e.g., ethylbenzene/ styrene) to nearly 21 bar (e.g.,propylene/propane) and is capable of separating feeds with high volumetric flowrates and various components that cover a range of relative volatilities from only 1.17 ( o-xylene/ m-xylene) to 81.2 (water/ ethylene glycol). Distillation provides a convenient and time-tested solution to separate a diversity of chemicals in a continuous manner with high purity. However, distillation has an enormous environmental footprint, resulting in the consumption of approximately 25% of all industrial energy use. The key issue is that distillation operates based on phase changes, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt
In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as rock salt or halite. Salt is essential for life in general (being the source of the essential dietary minerals sodium and chlorine), and saltiness is one of the basic human tastes. Salt is one of the oldest and most ubiquitous food seasonings, and is known to uniformly improve the taste perception of food. Salting, brining, and pickling are ancient and important methods of food preservation. Some of the earliest evidence of salt processing dates to around 6000 BC, when people living in the area of present-day Romania boiled spring water to extract salts; a salt works in China dates to approximately the same period. Salt was prized by the ancient Hebrews, Greeks, Romans, Byzantines, Hittites, Egyptians, and Indians. Salt became a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vapor–liquid Separator
In chemical engineering, a vapor–liquid separator is a device used to separate a vapor–liquid mixture into its constituent phases. It can be a vertical or horizontal vessel, and can act as a 2-phase or 3-phase separator. A vapor–liquid separator may also be referred to as a ''flash drum'', ''breakpot'', ''knock-out drum'' or ''knock-out pot'', ''compressor suction drum, suction scrubber'' or ''compressor inlet drum,'' or ''vent scrubber.'' When used to remove suspended water droplets from streams of air, it is often called a demister. Method of operation In vapor-liquid separators gravity is utilized to cause the denser fluid (liquid) to settle to the bottom of the vessel where it is withdrawn, less dense fluid (vapor) is withdrawn from the top of the vessel. In low gravity environments such as a space station, a common liquid separator will not function because gravity is not usable as a separation mechanism. In this case, centrifugal force needs to be utilised in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Souders–Brown Equation
In chemical engineering, the Souders–Brown equation (named after Mott Souders and George Granger Brown) has been a tool for obtaining the maximum allowable vapor velocity in vapor–liquid separation vessels (variously called ''flash drums'', ''knockout drums'', ''knockout pots'', ''compressor suction drums'' and ''compressor inlet drums''). It has also been used for the same purpose in designing trayed fractionating columns, trayed absorption columns and other vapor–liquid-contacting columns. A vapor–liquid separator drum is a vertical vessel into which a liquid and vapor mixture (or a flashing liquid) is fed and wherein the liquid is separated by gravity, falls to the bottom of the vessel, and is withdrawn. The vapor travels upward at a design velocity which minimizes the entrainment of any liquid droplets in the vapor as it exits the top of the vessel. Use The diameter of a vapor–liquid separator drum is dictated by the expected volumetric flow rate of vapor and li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
