Control Buoyancy float

Product concentration can be controlled by measuring a number of physical properties. On-stream composition analyzers are often used. Commonly used physical properties include density, boiling point rise, temperature/pressure combinations, temperature difference, conductivity, differential pressure, refractive index, buoyancy float, and viscosity. Each method has certain advantages as well as limitations. In all cases, however, a representative measurement location must be carefully selected to eliminate entrained air bubbles or excessive vibration, and the instrument must be mounted in an accessible location for cleaning and calibration. The location of the product quality transmitter with respect to the final effect should be considered also. Long piping runs between the product and the instrument increase deadtime, which in turn reduces the effectiveness of the control loop. 

Primarily used for feed density detection, the buoyancy float can also be applied to product density if a suitable mounting location near the evaporator can be found. Because flow will affect the measurement, the float must be located where the fluid is almost stagnant or where flow can be controlled (by recycle) and its effects zeroed out. A Teflon-coated float helps reduce drag effects. 

Floating vessels for offshore operations offer reduced installation costs but also present additional vulnerability factors. All floating structures must ensure buoyancy integrity is maintained otherwise the vessel may sink with catastrophic results. Similarly propulsion are provided at some installations to provided position stability. All major vessels are required by insurance requirements and most marine regulations to maintain buoyancy systems and loss of position stability will impact ongoing operations. Both of these systems can therefore be considered critical support systems and must be evaluated for risk and loss control measures either thorough duplication and protection measures or a combination of both. 

The most common method of marine pipeline construction utilizes a floating vessel on which the pipe is assembled in a horizontal position. As additional joints or sections of pipe are added to the already-completed segment, the barge is moved forward, actually moving out from under the completed pipeline. This is sometimes called the stovepipe method, named after the manner the pipe sections are added, one after another. This pipeline extends off the stern of the vessel and spans down to the sea bottom. It is supported part of the way down by a construction aid called a pontoon or stinger, This is basically a slender structure pinned to the vessel on one end and with built-in buoyancy that can be controlled so that it floats at the proper angle to the water surface to provide support to the pipeline. 

Timmermans, J., and Moes, A. J. Factors controlling the buoyancy and gastric retention capabilities of floating matrix capsules New data for reconsidering the controversy. J. Pharm. Sci. 83(l) 18-24, 1994. 

The most widely used applications reported in 1973 included rib structures in the fabrication of lightweight reinforced-plastic parts and as a core material in sandwich construction, bonded to metal, wood, or glass. Other applications are as reinforcements for aircraft-control surfaces, radome housings, fUler blocks under fuel cells, tank floats for indicating devices, and ribs, posts, and framing in houses and shelters. Due to its buoyancy characteristics cellulose acetate foam has been used in lifeboats, buoys, and other flotation devices (21). 

In many bony fish, some gases in the blood are channeled into another organ, the swim bladder. This organ is essentially a gas bag that helps the fish control its depth by adjusting its buoyancy. A fish can float higher in the water by increasing the volume of gas in the swim bladder. To sink, the fish reduces the amount of gas in the bladder. 

To gain an insight into how such reductions can be achieved it is important to consider how dust clouds are generated, and how they move or can be moved. Much of this pollution can be clearly seen, and the picture of particles apparently floating in the air may be one impression gained. However, floating in the classical sense is certainly not possible since buoyancy offered by the displacement of air by the particle would be insufficient to support the weight of that particle (Fig. 4). This absence of buoyancy means that the motion of the particle is likely to have a measure of independence of that of the air around it, a characteristic which must have profound implications for dust control. 

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