Capsule pipeline hydraulic

Pipelines to transport solids are called freight pipelines, of which three different types exist pneumatic pipelines, the use of which is known as pneumotransport or pneumatic conveying slurry pipelines, which may also be called hydrotransport or hydraulic conveying and capsule pipelines. When air or inert gas is used to move the solids in the pipeline, the system is called a pneumatic pipeline and often involves a wheeled vehicle inside the pipeline, propelled by air moving through the pipe (25). Slurry pipelines involve the transport of solid particles suspended in water or another inert liquid. Hydraulic capsule pipelines transport solid material within cylindrical containers, using water flow through the pipeline for propulsion. 

With annually increasing volumes of various fossil fuels to be handled and/or transported an interest arises in the new economical and operationally safe kinds of transport, including the pipeline one. Preliminary investigation has shown that application of a special kind of pipeline installations can be very useful for solving the problem to supply different countries by fossil fuels from distant finding place [1,2]. The hydraulic, pneumatic and capsules pipeline transport systems may be successfully used to solve this task in the near future. Of course, the state of knowledge in the field of pipeline transport requires applying also experimental research beside a numerical... 

The second way is a capsule pipeline transport. Hydraulic capsule pipeline and pneumatic capsule pipeline is the transport of freight encapsulated to cylindrical or spherical bodies, so called capsules (with diameter only slightly less than the pipe), conveyed through pipeline by liquid or gas, respectively. Hodgson Charles [8] and Jensen [9,10] referred to capsule pipelining as the third generation of pipelining. 

The comparison of hydraulic capsule pipeline transport with pipeline transport of oil products and slurry hydrotransport is particularly interesting. 

As follows from Figure 4, for coarse coal transport the power consumption of slurry pipelining reaches from 300 % to 100 % higher values than that in case of hydraulic capsule pipeline transport. The energy reduction increases with reduction of the operational velocity. 

Similar result brings comparison of power consumption reduction for transport of encapsulated viscous liquid (Russian oil) conveyed by water with conventional pipeline transport of the oil. Transport of viscous oil and oil products by means of capsule pipelining may again provide power consumption reduction from 50% to 70%, the reduction increases with operational velocity. Since for low temperature the oil viscosity significantly increases hydraulic capsule pipeline transport of highly viscous oil and oil products for long distances in arctic conditions can be economically attractive. Capsule pipeline transport could be recommended as suitable transport especially for longer distances when power consumption becomes the most important for operational cost. 

Liu, H. Design and operational considerations of hydraulic capsule pipelines. Proceedings of the Workshop on Capsule Pipelines, Tokyo, Japan, Jun 1992. Japanese Society of Multiphase Flow Tokyo, Japan, 1992 26-50. 

Keywords drag reduction hydraulic capsule pipeline poly(ethylene oxide)... 

X. Huang, Polymer Drag Reduction in Hydraulic Capsule Pipeline (HCP). M.S. Thesis, University of Missouri - Columbia (1994). 

Effect of radius of curvature, R, and central angle, a, of the bend section of pipe on threshold velocity of capsules, V/r, capsule liquid velocity ratio, Vc v , and hydraulic gradient U, is important to satisfy transport capacity and safe operation of capsule pipelining. Based on experimental investigation done with heavy cylindrical and spherical capsules [9-13] it was found that the threshold velocity is practically independent on central angle of the bend section (see Fig. 1), if the pipe curvature is adequate, as it is given by relationship [4,6]... 

H. Liu Capsule pipeline recent progress, Conf. Adv. Aerodyn. Hydraul. Fluid Meeh. ASCE, Minneapolis, MN, June 1986,8 pp. 

Assadollabaik, M. Liu, H. Westrich, P. Design and test of hydraulic capsules to transport grain. In Freight Pipelines] Liu, H., Round, G.F., Eds. Hemisphere Publishing Corporation New York, 1990. 

The minimum average liquid velocity which causes the motion of capsule under the drag produced by liquid in pipe is defined as threshold velocity, Vm When the drag exceeds friction between pipe and capsule, the capsule will start to move along a pipe bottom. Because the contact friction between pipe and capsule influences a capsule velocity and hydraulic gradient of capsule flow, which can be different from the values determined for a straight pipe, it is necessary to take it into account for design of commercial pipelines to ensure safe and economical operation. 

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