Conveying pipes

Piperack is the elevated supporting stmcture used to convey piping between equipment. This stmcture is also utilized for cable trays associated with electric power distribution and for instmment trays. 

In this chapter the pressure drop for pneumatic conveying pipe flow is studied. The conventional calculation method is based on the use of an additional pressure loss coefficient of the solid particles. The advantage of this classical method is that in principle it can be applied to any type of pneumatic flow. On the other hand, its great disadvantage is that the additional pressure loss coefficient is a complicated function of the density and the velocity of the conveying gas. z lso, it is difficult to illustrate the additional pressure loss coefficient and this makes the theoretical study of it troublesome. 

Experimentally generated data have quantitatively shown a tendency of increased solids deposition at lower gas mass flow rate in slug flows except that, below a certain amount of solids mass flow rate, the deposition becomes independent of the gas flow rate, which is due to particle fluidised motion before a slug flow commences. Further work will focus on experiments with a wider range of flow conditions using sophisticated measuring tools to validate the model and to build up a quantitative protocol for the description of solids deposition in conveying pipes. 

A single particle, initially at rest at the bottom wall of the conveying pipe, may undergo various states of motion when the gas velocity increases. Single-particle motion can occur in one or a combination of the following states [Zenz, 1964] ... 

Haag, A. (1967). Velocity Losses in Pneumatic Conveyer Pipe Bends. British Chemical Engineering, 12, 65. 

D) Is the application one of containing (process vessels, storage tanks, scrubbers, etc.), conveying (pipe, valves, fittings, etc.) or exhausting (hoods, ducts, stacks, etc.). 

The cutters in use in mechanical sampling are divided into diverter types and bucket types. Both types are used to cut a stream falling due to gravity off the end of a conveyor belt or from the discharge end of a pneumatic conveying pipe or a chute. 

The conveying pipes may be made of materials compatible with the processed liquid rubber hose or suitably lined pipes are serviceable for corrosive fluids. Sharp bends are to be avoided. 

Fig. 5.65 Sketch and photograph of a model experiment explaining the different types of build-up in a horizontal pneumatic conveying pipe.

The head losses between the working reservoir and the exit of the reactor tank are due almost entirely to the velocity head and friction losses across the active and beryHium sections, with relatively small losses contributed by the conveying pipe line There are block valves and a flow control valve in the inlet line to the reactor, but there are no obstructions inthepipe line from the reactor to the seal tank. 

A laboratory or pilot-scale conveying system comprising hoppers, air compressor, rotary feeder, polyvinyl chloride (PVC) conveying pipe, control valves, pressure transducers, rotameter, and electronic weight indicator. Polypropylene granules of different size, as testing material. 

Operate the compressor to introduce air into the conveying pipe connected to the feed hopper by means of the rotary feeder, by opening the air control valve. 

Figure 8.3 Section of conveying pipe basis for momentum equation The momentum balance equation is ...

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