Pipe fluid systems

Measurement by Electromagnetic Effects. The magnetic flow meter is a device that measures the potential developed when an electrically conductive flow moves through an imposed magnetic field. The voltage developed is proportional to the volumetric flow rate of the fluid and the magnetic field strength. The process fluid sees only an empty pipe so that the device has a very low pressure drop. The device is useful for the measurement of slurries and other fluid systems where an accumulation of another phase could interfere with flow measurement by other devices. The meter must be installed in a section of pipe that is much less conductive than the fluid. This limits its appHcabiHty in many industrial situations. 

Steam traeing is the most eommon type of industrial pipe traeing. In 1960, over 95 pereent of industrial traeing systems were steam traeed. By 1995, improvements in eleetrie heating teehnology inereased the eleetrie share to 30 to 40 pereent, but steam traeing is still the most eommon system. Fluid systems other than steam are rather uneommon and aeeount for less than 5% of traeing systems. 

The temperature difference may not remain constant throughout the flow path. Plots of temperature vs. pipe length for a system of two concentric pipes in which the annular fluid is cooled and the pipe fluid heated are shown in Figures 2-2 and 2-3. When the two fluids travel in opposite directions, as in Figure 2-2, they are in countercurrent flow. When the fluids travel in the same direction, as in Figure 2-3, they are in co-current flow. 

As von Nimitz points out, only cyclic stresses are directly related to failure probability. These stresses are often produced by pulsations in the fluid system, by mechanical vibrations produced by the mechanical movement of certain equipment components, and as a result of the fluid pulsations. Figure 13-8 lists the sequence of events that leads to most failures of equipment and piping. 

Examine geometry and size of piping/flowline systems to ensure process streams are subject to minimal pressure changes and fluctuations, changes in fluid direction and flow rates consistent with production requirements. 

E. B. Wylie and co-workers, Fluid Transients in Systems, Prentice Hall, New York, 1993 J. Zarbua, Water Hammer in Pipe Fine Systems, Elsevier Science Publishing Co., New York, 1993. 

To develop the related integrated systems (such as the heat transfer system piping, fluids, heat exchangers, instrumentation) that are required to commercialise the HyS process. 

The objective of this chapter is to introduce you to some of the fluid flow problems encountered in the process design of a typical pipe-flow system, illustrated in Figure 1, where a fluid is pumped from one vessel into another through a section of pipework. 

The energy required to pump a liquid food through a pipe line can be calculated from the mechanical eneigy balance (MEB) equation. The MEB equation can be used to analyze pipe flow systems. For the steady-state flow of an incompressible fluid, the MEB can be written as follows (Brodkey, 1%7) ... 

There are three jet grouting systems in common use. These are the single jet or monofluid system, the two fluid, and the three fluid systems. All systems require the placement of the jet pipe to the bottom of the depth to be treated. This is done using conventional drilling methods appropriate for the soil being treated. Depths of 150 feet have been successfully treated, and greater depths are possible under certain conditions. Any soil in which the jet pipe can be placed can be successfully treated. Adverse condition include soil deposits which contain large amounts of boulders. 

So far all the discussion has been about steady flow well downstream of the pipe entrance in straight circular pipe. This is the simplest and one of the most important cases of fluid friction. However, in many fluid systems we must take into account the effect of valves, elbows, etc. They are much more complex to analyze than the one-dimensional flows we have considered so far. (The student is advised to take apart an ordinary household faucet and study its flow path it is much more complicated than that of a straight pipe.) Efforts have been made to calculate the friction losses in such fittings, and the results have been correlated in several convenient ways which allow us to treat them as if they were one-dimensional problems. 

The 3-ft-diameter, horizontal main cooling line from a nuclear reactor breaks. The pressure inside the reactor is 1000 psia, and the water surface inside the reactor is 20 ft above the broken line. The exiting fluid (a steam-water mixture) has a density of 501bm/ft Estimate the horizontal force on the pipe-reactor system due to the flow through the broken pipe. Assume frictionless flow. 

PFTR Pipe/Tube, Empty Pipe for Fluid Systems 225... 

Plant Design for Protection Against Postulated Piping Failures in Fluid Systems Outside Containment... 

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