Baffles equations

Wagner equation Wagner number Wakamatsu reaction Waldhof fermentor Walkman Wallace plasticity Wallach procedure Wall baffles Wallboard Wall geometries Wallpaper paste Wallpaper pastes Wallpapers Wall plaster Walnut oil... 

This implies that the LMTD or M I D as computed in equations 20 through 26 may not be a representative temperature difference between the two heat-transferring fluids for aU tubes. The effective LMTD or M ID would be smaller than the value calculated, and consequentiy would require additional heat-transfer area. The tme value of the effective M I D may be determined by two- or three-dimensional thermal—hydrauUc analysis of the tube bundle. Baffle—Tube Support PlateXirea. The portion of a heat-transfer tube that passes through the flow baffle—tube support plates is usuaUy considered inactive from a heat-transfer standpoint. However, this inactive area must be included in the determination of the total length of the heat-transfer tube. 

AM(from equation 46) + AM(bypass flow) + AM(entrance/exit effects) + AM (baffle plates)... 

A. Solid particles suspended in agitated vessel containing vertical baffles, continuous phase coefficient -2 + 0.6Wi f,.Wi D Replace Osi p with Vj = terminal velocity. Calculate Stokes law terminal velocity [S] Use log mean concentration difference. Modified Frossling equation K, -< T.d,P. [97] [146] p.220... 

Previous equations determine the pressure drop across the tube bundle. For the additional drop for flow through the free area above, below, or around the segmental baffles use... 

Propeller Yes No limitation 0.54 (Npe) - (Np,) --5 45 pitched, four-blade impeller. Fquation is based on limited data with regard to propeller pitch and vessel baffling. Divide hj obtained with this equation by a factor of about 1.3. 

This jacket is considered a special case of a helical coil if certain factors are incorporated into equations for calculating outside-film coefficients. In the equations at left and below, the equivalent heat transfer diameter D. for a rectangular cross-section IS equal to four times the width of the annular space, w and IS the mean or centerline diameter of the coil helix. Velocities are calculated from the actual cross-section of the flow area. pw. where p IS the pitch of the spiral baffle, and from the effective mass flowrate. W. through the passage. The leakage around spiral baffles is considerable, amounting to 35-50% of the total mass flowrate. The effective mass flowrate is about 60% of the total mass flowrate to the jacket W =... 

L the shell-side fluid makes one pass from inlet to outlet. With a longitudinal baffle, and with the nozzles placed 180° around the shell, the shell-side fluid would be forced to enter at the left, flow to the right to get around the baffle, and flow to the left to reach the exit nozzle. This would be required to approximate true counter-current flow, which was assumed in the heat transfer equations of Chapter 2. 

There are many baffle type impingement separators. The efficiency of operation for entrainment is entirely a function of the contacting action inside the particular unit. There are no general performance equations which will predict performance for this type of unit therefore manufacturers performance data and recommendations should be used. A few of the many available units are shown in Figures 4-28 to 4-31. Many use the Chevron-style verdcal plates as shown in Figures 4-17A and 4-30. 

Exponent in scale-up equation, describing type/degree of mixing required, Eigure 5-32, or number of samples in statistics Number of impellers Number of tube baffles (vertical)... 

Total number of actual trays in tower Number of caps per tray Number of slots per bubble cap Valve density, number of valves per ft or Number of valve units on a valve tray Depth of notches in weir, in or Exponent defined by Equations 8-288 and 327 Dry tray pressure drop for 50% cut baffles, in. liquid per baffle or... 

Calculate the shell-side dry-gas film coefficient, hg or h, for outside tube conditions. Assume a baffle spacing or about equal to one shell diameter. Use the shell-side method described in Equation 10-48 and Figure 10-54. This is necessary for inlet conditions and then must be checked and recalculated if sufficient change occurs in the mass flow rate, G, to yield a change in hg. 

From equation 10-48 for use with Figure 10-54, assume 18-in. baffle spacing ... 

Figure 10-140 is used for determining the friction factor (dimensional) for segmental type baffles. The loss across the tube bundle and through the baffle window is represented in the combined factor, f, which is to be used with the equation for pressure drop. ... 

The baffle used in the preceding equation has 20% segmental cuts. Shell-side cross-flow velocity ... 

It could be shown (see Sect. 6) that in stirred vessels with baffles and under the condition of fully developed turbulence, particle stress can be described by Eqs. (2) and (4) alone. The turbulent eddys in the dissipation range are decisive for the model particle systems used here and many biological particle systems (see Fig. 2), so that the following equation applies to effective stress ... 

In liquid mixing systems, baffles are used to suppress vortexing. Since vortexing is a gravitational effect, the Froude number is not required to describe baffled liquid mixing systems. In this case the exponent y in equations 5.17 and 5.18 is zero and FryM = 1. 

Figure 5.8 shows the power curve for the standard tank configuration geometrically illustrated in Figure 5.5. Since this is a baffled non-vortexing system, equation 5.20 applies.

Theoretical studies are primarily concentrated on the treatment of flame blow-off phenomenon and the prediction of flame spreading rates. Dunskii [12] is apparently the first to put forward the phenomenological theory of flame stabilization. The theory is based on the characteristic residence and combustion times in adjoining elementary volumes of fresh mixture and combustion products in the recirculation zone. It was shown in [13] that the criteria of [1, 2, 5] reduce to Dunskii s criterion. Longwell et al. [14] suggested the theory of bluff-body stabilized flames assuming that the recirculation zone in the wake of the baffle is so intensely mixed that it becomes homogeneous. The combustion is described by a second-order rate equation for the reaction of fuel and air. 

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