Horizontal flows

Clarifiers. The largest user of clarifiers is probably the water-treatment industry. The conventional one-pass clarifier uses horizontal flow in circular or rectangular vessels (Eig. 2) with feed at one end and overflow at the other. The feed is preflocculated in an orthokinetic (paddle) flocculator... 

Circular raking mechanisms are sometimes also used ia square basias with horizontal flow across the basia. Such designs have to iacorporate supplementary rake arms that reach iato the corners of the square vessel (Fig. 3). 

Fig. 6. Approaches to minimising entrapment and impingement of fish and large aquatic invertebrates, eg, blue crabs, on trash screens at intakes, (a) An inlet pump house with vertical traveling screens mounted flush with a river shoreline to minimise obstmctions to animal movements (b) parallel flow to direct fish to a recovery chamber that returns to the water body (c) a velocity cap atop a vertical, offshore inlet induces a horizontal flow which fish avoid...

Total pressure drop for vertical upflow of gases and solids includes acceleration and fric tional affec ts also found in horizontal flow, plus potential energy or hydrostatic effects. Govier and Aziz review many of the pressure drop calculation methods and provide recommendations for their use. See also Yang AIChE J., 24, 548-552 [1978]). 

FIG. 17-70 Horizontal-flow plate precipitator used in a cement plant. Western Precipitation Division, Joy Manufactuting Company. )... 

Fi is positive for upflow, negative for downflow, and zero for horizontal flow... 

Figure 7 The production and emission of NO during denitrification in agricultural soil treated with NO3 fertilizer (KNO3) and the nitrification inhibitor Dyciandiamide (10%) under aerobic (air) and anerobic conditions (N,). Fluxes are means from three soil columns, error bars represent standard deviations from the mean. V = vertical flow through the column H = Horizontal flow over the soil surface.

Persistent vertical motions are linked to the horizontal motions. If there is divergence (spreading) of the horizontal flow, there is sinking (downward vertical motion) of air from above to compensate. Similarly, converging (negative divergence) horizontal air streams cause upward vertical motions,... 

If a bottle is placed in the bench, a wake is easily created in the legitni with horizontal flow. This is depicted visually with smoke in Fig. 10.58. If the bottle is situated close to the opening of the unit, ambient air will be entrained intt> the dean zone in the bench. The length of the reversed region can be < sti mated to two to three times the diameter of the bottle, and can reach twice this length w hen the bottle is situated just beside the side wall. 

FIGURE I Q.60 Dispersion of smoke in a horizontal flow bench (wake region behind small bottles I... 

Low-velocity supply air enters the space above the operator, providing a clean air zone around an operator working in a contained area. It is arranged so that the contaminated air flows toward the exhaust openings. The low-velocity supply air is usually discharged vertically above the worker, although horizontal flow can be used. A typical example of a workbench is shown in Fig. 10.88. 

I he configuration B1 uses the same flow distribution inside the room as is common in horizontal flow cleanrooms. 

Pipe I.D. Inches Horizontal Flow Pattern Eleva- tion Factor, F, Ft./sec.. Gas Vel. 

Spacing of the plates and their angles is a part of the design using the manufacturers data. Muldple pass designs can result in higher recovery efficiencies. The units can be designed/installed for vertical or horizontal flow. 

The hot well is the sump where the barometric leg is sealed. It must be designed to give adequate cross-section below the seal leg and for upward and horizontal flow over a seal dam or weir. At sea level the hot well must be a minimum of 34.0 ft below the base of the barometric condenser. For safety to avoid air in-leakage, a value of 35-36 ft is used. For an altitude corresponding to a 26-in. Hg. barometer, the theoretical seal height is 29.5 ft actual practice still uses about 34 ft. 

At all points in a system, the static pressure is always equal to the original static pressure less any velocity head at a specific point in the system and less the friction head required to reach that point. Since both the velocity head and friction head represent energy and energy cannot be destroyed, the sum of the static head, the velocity head, and the friction head at any point in the system must add up to the original static head. This is known as Bernoulli s principal, which states For the horizontal flow of fluids through a tube, the sum of the pressure and the kinetic energy per unit volume of the fluid is constant. This principle governs the relationship of the static and dynamic factors in hydraulic systems. 

Notes Nos. 1-5 were tested with horizontal flow and Nos. 6-18 with vertical upflow. 

There are several possible explanations of the apparent conflict between Figs. 34 and 35. One possible explanation, for example, would be that the vertical upflow curve drawn in Fig. 34 may not be a straight line, but should perhaps curve upwards (the data itself shows some signs of this) toward the uppermost point of the horizontal flow line, which corresponds to the rod bundle in question. It will be seen later, however, that this would not appear to be the explanation. In addition, there is the fact that all the horizontal flow data in Fig. 34, as well as the new data in Fig. 35, are for a test pressure of 1215 psia, whereas the vertical upflow data in Fig. 34 refer to 1000 psia. Although there is no evidence to indicate the effect of pressure in the case of rod-bundle systems with round tubes, it is found that increasing pressure from... 

For horizontal flow, or where the effects of change of height may be neglected, as normally with gases, equation 2.57 simplifies to ... 

In horizontal flow, the flow pattern will inevitably be more complex because the gravitational force will act perpendicular to the pipe axis, the direction of flow, and will cause the denser component to flow preferentially nearer the bottom of the pipe. Energy transfer between the phases will again occur as a result of the difference in velocity, but the net force will be horizontal and the suspension mechanism of the particles, or the dispersion of the fluid will be a more complex process. In this case, the flow will not be symmetrical about the pipe axis. 

Flow regimes and flow patterns Horizontal flow... 

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