Grid pressure drop

If turndown is desired, the grid pressure-drop criteria (Eqs. 3 and 4) must apply at the minimum gas flow rate. Also, if the grid is curved, i.e., concave, convex, or conical, the criterion must apply with respect to the... 

The plenum, or windbox, is the chamber immediately below the grid. If the bed-pressure-drop-to-grid-pressure-drop ratio is high enough, the plenum design will probably not be that important. However, for the case where this ratio is marginal, the plenum design may determine whether the bed will operate satisfactorily. 

K = grid pressure-drop coefficient Eq. (6) for upward gas entry 0.1 for lateral and downward gas entry... 

FIGURE 7-5 An inexplicable drop in air-grid pressure drop accompanied by an increase in aiterburn indicates air-grid damage. 

AP = Normalized air grid pressure drop, psi AP = Observed air grid pressure drop, psi V = Observed actual volume of air, ft ... 

Check air grid pressure drop Afterburn problems... 

The following equations can be used to design perforated plates, spargers, and bubble cap types of grids Pressure drop across the grid ... 

The parameters in Eq. (11) are defined in Fig. 6. Eq. (11) ensures that the pressure drop in the manifold is negligible compared to the pressure drop in the holes, which are determining the grid pressure drop. 

Tyagi, A., "Grid pressure drop and solid leakage in a large gas-solid fluidized bed", M.E.Sc. thesis Engineering Science, The University of Western Ontario, London, Canada, 1984. 

Grid Pressure Drop Typically 1-2 psi, at Least 30% of Bed Head... 

Usually used stacked, and as first layers on support grids for smaller packing above. Pressure drop relatively low, channeling reduced for comparative stacked packings. No side wall thrust. 

The first requirement of the grid is that it distribute gas evenly across the fluid bed. This is accomplished by having a large number of holes and a high pressure drop across the grid. The high pressure drop assures that flow will be uniform through all holes and that flow stabihty will not be much influenced by behavior of the fluid bed. 

Piping to Burners - First and second stage piping and headers, as well as the burner lines themselves, are sized to minimize pressure drop and velocity effects. Thus, maldistribution of flow to the burners will be minimized. The burner lines are fabricated from standard 1(X) mm pipe, and are arranged in a split grid layout with distribution headers and split feed lines on opposite sides, for both first and second stage burners. First and second stage headers must be sloped so that any condensate will drain back to the seal drums. However, the burner lines must be accurately installed in a horizontal plane. 

Grid packing is probably the newest type packing. It is lower in pressure drop, tind has higher capacity, and lower efficiency than the other types. (See Figures 9-6PP-9-6UU.)... 

Figure 9-6RR. Intalox Grid-type packing useful for fouling, solids and heat transfer high-strength, low-pressure drop, high capacity, better efficiency than most structured and random packing. Used by permission of Norton Chemical Process Products Corp., Bull. IG-1.

Not much performance data available, but in gen- Wood Grids eral slightly better than Raschig ring, pressure drop slightly higher. High side wall thrust. 

Pressure drop data for several styles and arrangements of drip point grid tile are given in Figures 9-25A-9-25E. These are not included in the general GPDC correlations for random packings. 

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