Horizontal and Vertical Transport

In a horizontal conveying pipeline, motion of the particles is not always straight in the horizontal direction. Particles constantly fall down to the bottom of the pipe by 

Inclined pipelines require the highest gas velocity to convey the same amount of solid materials when compared to both vertical and horizontal conveying. In this case, gas flow has to overcome the forces associated with horizontal conveying and the tendency of materials to slide back down the incline. In practice, a slope of less than 15° or more than 80° from the horizontal need not be considered an incline [Williams, 1983]. 

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Transport and dijfusion. With the exception of N2, O2, Ar, and numerous other long-lived species that are well-mixed in the bulk of the atmosphere, horizontal and vertical transport are closely coupled with chemical reactions in controlling atmospheric trace-substance concentrations. 

POC/ Th (mol C/dpm is the ratio on sinking particles and is the decay constant of " Th (0.029 d ). This approach makes no assumptions about residence times, although it implicitly assumes that sinking biogenic particles are the principal carriers of " Th atoms, that the POC/ Th ratio on sinking particles can be measured, that steady state applies and that horizontal and vertical transport of " Th via advection of water are negligible. 

Gustafsson O, Buesseler KO, Geyer WR, Moran SB, Gschwend PM (1998) An assessment of the relative importance of horizontal and vertical transport of particle-reactive chemicals in the coastal ocean. Cont Shelf Res 18 805-829... 

Figure 5.10. Closed belt (zipper) for conveying in any direction (Stephens-Adamson Co.), (a) Arrangement of pulley, feed hopper and open and closed belt regions, (b) The tubular belt conveyor for horizontal and vertical transport a section of the zippered closed belt is shown, (c) Showing how the zipper closes (on downward movement of the belt in this sketch) or opens (on upward movement of the belt).

In IFS tracer forecast mode the CTM provides initial condition for the chemical tracers (NOx, NO2, SO2, CO, HCHO and O3) and 3D fields of tracer tendencies due to emissions, deposition and chemical conversion to IFS. The IFS simulates the horizontal and vertical transport of these tracers and applies the CTM tendency data in order to account for the source and sink processes not simulated in the IFS. The CTM itself run as in CTM forecast mode. The feedback option enables replacing the CTM concentration fields, in particular the initial conditions, with the tracer fields of the IFS. 

Table 1-8. Time Constants for Horizontal and Vertical Transport by Atmospheric Mean Motions and Eddy Diffusion11... 

The steady-state odd oxygen model of (4.6) predicts that the O3 concentration should be proportional to the square root of the Oo photolysis rate. We see that, in fact, ozone concentration and O2 photolysis rate do not peak together. The explanation for the lack of alignment of these two lies in the role of horizontal and vertical transport in redistributing stratospheric air mas.ses. Recalling the discu.ssion of stratospheric air circulation in Chapter 1, it is evident that the ozone bulge in the northern polar regions is a result, for example, of... 

In this chapter the choking and saltation velocities will be used to mark the boundaries between dilute phase transport and dense phase transport in vertical and horizontal pipelines, respectively. These terms are defined below in considering the relationships between gas velocity, solids mass flow rate and pressure drop per unit length of transport line in both horizontal and vertical transport. 

However, even within the dense phase regime a number of different flow patterns occur in both horizontal and vertical transport. Each of these flow patterns has particular characteristics giving rise to particular relationships between gas velocity, solids flow rate and pipeline pressure drop. In Figure 8.7 for example, five different flow patterns are identified within the dense phase regime for horizontal transport. 

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