|
Settling Tank, Hafodyrynys Colliery
Settling is the process by which particulates move towards the bottom of a liquid and form a sediment. Particles that experience a force, either due to gravity or due to centrifugal motion will tend to move in a uniform manner in the direction exerted by that force. For gravity settling, this means that the particles will tend to fall to the bottom of the vessel, forming sludge or slurry at the vessel base. Settling is an important operation in many applications, such as mining, wastewater and drinking water treatment, biological science, space propellant reignition, and scooping. Physics For settling particles that are considered individually, i.e. dilute particle solutions, there are two main forces enacting upon any particle. The primary force is an applied force, such as gravity, and a drag force that is due to the motion of the particle through the fluid. The applied force is usually not affected by the particle's velocity, whereas the drag force is a function o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematically, density is defined as mass divided by volume: : \rho = \frac where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate – this quantity is more specifically called specific weight. For a pure substance the density has the same numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium and iridium are the densest known elements at standard conditions for temperature and pressure. To simplify comparisons of density across different s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbidity
Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids can contain suspended solid matter consisting of particles of many different sizes. While some suspended material will be large enough and heavy enough to settle rapidly to the bottom of the container if a liquid sample is left to stand (the settable solids), very small particles will settle only very slowly or not at all if the sample is regularly agitated or the particles are colloidal. These small solid particles cause the liquid to appear turbid. Turbidity (or haze) is also applied to transparent solids such as glass or plastic. In plastic production, haze is defined as the percentage of light that is deflected more than 2.5° from the incoming light direction. Causes and effects Turbidity in open water may be caused by growth of phyto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarifier
Clarifiers are settling tanks built with mechanical means for continuous removal of solids being deposited by sedimentation. A clarifier is generally used to remove solid particulates or suspended solids from liquid for clarification and/or thickening. Inside the clarifier, solid contaminants will settle down to the bottom of the tank where it is collected by a scraper mechanism. Concentrated impurities, discharged from the bottom of the tank, are known as sludge, while the particles that float to the surface of the liquid are called scum. Applications Pretreatment Before the water enters the clarifier, coagulation and flocculation reagents, such as polyelectrolytes and ferric sulfate,Brentwood Industries, Inc. (2013)"Tube Settler Systems For Clarification." Accessed 14 October 2013. can be added. These reagents cause finely suspended particles to clump together and form larger and denser particles, called flocs, that settle more quickly and stably. This allows the separation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamella Clarifier
A lamella clarifier or inclined plate settler (IPS) is a type of clarifier designed to remove particulates from liquids. Range of applications Lamella clarifiers can be used in a range of industries, including mining and metal finishing, as well as to treat groundwater, industrial process water and backwash from sand filters. Lamella clarifiers are ideal for applications where the solids loading is variable and the solids sizing is fine. They are more common than conventional clarifiers at many industrial sites, due to their smaller footprint. One specific application is pre-treatment for effluent entering membrane filters. Lamella clarifiers are considered one of the best options for pre-treatment ahead of ultrafiltration. Their all-steel design minimizes the chances that part of the inclined plate will chip off and be carried over into the membrane, especially compared to tube settlers, which are made of plastic. Further, lamella clarifiers may maintain the required water qua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coagulation (water Treatment)
In water treatment, coagulation and flocculation involve the addition of compounds that promote the clumping of fine floc into larger floc so that they can be more easily separated from the water. Coagulation is a chemical process that involves neutralization of charge whereas flocculation is a physical process and does not involve neutralization of charge. The coagulation-flocculation process can be used as a preliminary or intermediary step between other water or wastewater treatment processes like filtration and sedimentation. Iron and aluminium salts are the most widely used coagulants but salts of other metals such as titanium and zirconium have been found to be highly effective as well. Factors Coagulation is affected by the type of coagulant used, its dose and mass; pH and initial turbidity of the water that is being treated; and properties of the pollutants present. The effectiveness of the coagulation process is also affected by pretreatments like oxidation. Mechanis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waste Water Treatment
Wastewater treatment is a process used to remove contaminants from wastewater and convert it into an effluent that can be returned to the water cycle. Once returned to the water cycle, the effluent creates an acceptable impact on the environment or is reused for various purposes (called water reclamation). The treatment process takes place in a wastewater treatment plant. There are several kinds of wastewater which are treated at the appropriate type of wastewater treatment plant. For domestic wastewater (also called municipal wastewater or sewage), the treatment plant is called a sewage treatment plant. For industrial wastewater, treatment either takes place in a separate industrial wastewater treatment plant, or in a sewage treatment plant (usually after some form of pre-treatment). Further types of wastewater treatment plants include agricultural wastewater treatment plants and leachate treatment plants. Processes commonly used in wastewater treatment include phase sepa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Food Processing
Food processing is the transformation of agricultural products into food, or of one form of food into other forms. Food processing includes many forms of processing foods, from grinding grain to make raw flour to home cooking to complex industrial methods used to make convenience foods. Some food processing methods play important roles in reducing food waste and improving food preservation, thus reducing the total environmental impact of agriculture and improving food security. Primary food processing is necessary to make most foods edible, and secondary food processing turns the ingredients into familiar foods, such as bread. Tertiary food processing has been criticized for promoting overnutrition and obesity, containing too much sugar and salt, too little fiber, and otherwise being unhealthful in respect to dietary needs of humans and farm animals. Process Primary food processing Primary food processing turns agricultural products, such as raw wheat kernels or livest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storage Tank
Storage tanks are containers that hold liquids, compressed gases (gas tank; or in U.S.A "pressure vessel", which is not typically labeled or regulated as a storage tank) or mediums used for the short- or long-term storage of heat or cold. The term can be used for reservoirs (artificial lakes and ponds), and for manufactured containers. The usage of the word tank for reservoirs is uncommon in American English but is moderately common in British English. In other countries, the term tends to refer only to artificial containers. In the USA, storage tanks operate under no (or very little) pressure, distinguishing them from ''pressure vessels''. Storage tanks are often cylindrical in shape, perpendicular to the ground with flat bottoms, and a fixed frangible or floating roof. There are usually many environmental regulations applied to the design and operation of storage tanks, often depending on the nature of the fluid contained within. Above-ground storage tanks (ASTs) differ from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Pressure
In compressible fluid dynamics, impact pressure (dynamic pressure) is the difference between total pressure (also known as pitot pressure or stagnation pressure) and static pressure. In aerodynamics notation, this quantity is denoted as q_c or Q_c. When input to an airspeed indicator, impact pressure is used to provide a calibrated airspeed reading. An air data computer with inputs of pitot and static pressures is able to provide a Mach number and, if static temperature is known, true airspeed. Some authors in the field of compressible flows use the term ''dynamic pressure'' or ''compressible dynamic pressure'' instead of ''impact pressure''.L. J. Clancy (1975) ''Aerodynamics'', Section 3.12 and 3.13"the dynamic pressure is equal to ''half rho vee squared'' only in incompressible flow."Houghton, E.L. and Carpenter, P.W. (1993), ''Aerodynamics for Engineering Students'', Section 2.3.1 Isentropic flow In isentropic flow the ratio of total pressure to static pressure is given by: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drag Coefficient
In fluid dynamics, the drag coefficient (commonly denoted as: c_\mathrm, c_x or c_) is a dimensionless quantity that is used to quantify the drag or resistance of an object in a fluid environment, such as air or water. It is used in the drag equation in which a lower drag coefficient indicates the object will have less aerodynamic or hydrodynamic drag. The drag coefficient is always associated with a particular surface area. The drag coefficient of any object comprises the effects of the two basic contributors to fluid dynamic drag: skin friction and form drag. The drag coefficient of a lifting airfoil or hydrofoil also includes the effects of lift-induced drag. The drag coefficient of a complete structure such as an aircraft also includes the effects of interference drag. Definition The drag coefficient c_\mathrm d is defined as c_\mathrm d = \dfrac where: * F_\mathrm d is the drag force, which is by definition the force component in the direction of the flow velocity; * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Waste Water Treatment")
