Upward crossing

Baffles in a horizontal in-shell condenser are oriented with the cuts vertical to facilitate drainage and eliminate the possibility of flooding in the upward cross-flow sections. Pressure drop on the vapor side can be estimated by the data and method of Diehl and Unruh [Pet. Refiner, 36(10), 147 (1957) 37(10), 124 (1958)]. 

Figure 8.8 shows a simple example of how to calculate the irregularity factor. The number of the zero upward crossing is E[0] = 4 and the number of peaks is E[P] = 7, therefore it is y = 4/7 = 0.57. Irregularity factor is found in the range of 0-1. Note that when y = 0 there is an infinite number of peaks for every zero up crossing. This is characteristic of a wide-band random process. The value of y = 1,... 

If a sedimentation experiment is carried out long enough, a state of equilibrium is eventually reached between sedimentation and diffusion. Under these conditions material will pass through a cross section perpendicular to the radius in both directions at equal rates downward owing to the centrifugal field, and upward owing to the concentration gradient. It is easy to write expressions for the two fluxes which describe this situation ... 

A gravity diyer consists of a stationaiy vertical, usually cylindrical housing with openings for the introduction of sohds (at the top) and removal of solids (at the bottom). Gas flow is through the sohds bed and may be cocurrent or countercurrent and, in some instances, cross-flow. By definition, the rate of gas flow upward must be less than that required for fluidization. 

The suspension of a single sohd particle should depend primarily on the upward velocity at a given point and also should be affected by the uniformity of this velocity profile across the entire tank cross section. There are upward velocities in the tank and there also must be corresponding downward velocities. 

In practice, however, the liquid velocity relative to fixed particles, Uf, is not very useful. Instead, the velocity of settling relative to the walls of an apparatus, Uf - u, is of practical importance. The volume of the solid phase moving downward should be equal to that of liquid moving upward. This means that volume rates of these phases must be equal. Consider a column of slurry having a unit cross section and imagine the liquid and solid phases to have a well defined interface. The column of solid phase will have a base 1 - e, and the liquid column phase will have a base e. Hence, the volumetric rate of the solid column will be (1 - e)u, and that of the liquid column will be (Uf - u)e. Because these flowrates are equal to each other, we obtain... 

When a chilled air jet is supplied at the angle olq upward, it will cross the level of the supply outlet at the distance Xq. This distance can be calculated by substituting 2 = 0 in Eq. (7.102) ... 

High Receptor Hoods The important variable that distinguishes receptor hoods from other exterior hoods is the upward airflow set in motion by the heated source. Let us first consider the more general (and difficult) case of a high hood. Assume for simplicity that the source and the hood are circular in cross-section. The basic geometry used in this case is shown in Fig. 10.36. 

The DTB, crystallizer has a relatively slow-speed propeller agitator located within a draft-tube which draws a fine-crystal suspension up to a boiling zone of wide cross-sectional area, as shown in Figure 3.3(i). The fine-crystal magma then passes through an annular zone in which an additional baffle is located. Liquor flow continues upwards at low velocity while crystals settle out and fall to the base of the vessel. Liquor from the external pumped loop provides an up-... 

Balanced relief valves are spring-loaded valves that contain a bellows arrangement to keep back-pressure from affecting the set point. Figure 13-4 shows a cross section of a balanced relief valve, and Figure 13-5 is a schematic that shows how the valve operates. The bonnet is vented to atmosphere and a bellows is installed so that the back-pressure acts both downward and upward on the same area of the disc. Thus, the forces created by the back-pressure always cancel and do not affect the set point. 

Most studies have used the Souders-Brown [67] droplet settling velocity concept to relate entrainment flooding. In this mechanism, flooding develops due to a sufficiently high upward vapor velocity through the cross-section of the net area of the column to suspend droplets, and is expressed as the Souders-Brown flooding constant, Csb> [94, 183, 184]. 

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. 

The hydrostatic pressure has two effects an upward force acting on the wall cross-section of the sub, and a downward stress due to the lateral compression of the subwall. 

In this case, the fluid column has a uniform cross section, so the area of the output piston is the same as the area of the input piston, or 10 square inches. Therefore, the upward force on the output piston is 100 pounds and is equal to the force applied to the input piston. All that was accomplished in this system was to transmit the 100 pounds of force around the bend. However, this principle underlies practically all mechanical applications of hydraulics or fluid power. 

Figures 62.8, 62.9, 62.10 show the data for generator fan failure plotted on exponential, normal and log normal hazard paper respectively. The exponential plot is a reasonably straight line which indicates that the failure rate is relatively constant over the range of the data. It should be noted that the reason the probability scale on the exponential hazard plot is crossed out is because that is not the proper way to plot data. (This will be discussed later.) The normal plot is curved concave upward which...

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