Grid-Support

Rather than use a cloth, a granular medium consisting of layers of particulate solids on a support grid can be used. Downward fiow of the mixture causes the solid particles to be captured within the medium. Such deep-bed filters are used to remove small quantities of solids from large quantities of liquids. To release the solid particles captured within the bed, the flow is periodically reversed, causing the bed to expand and release the particles which have been captured. Around 3 percent of the throughput is needed for this backwashing. 

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. 

It a bottom node (i.j) is tally nwiten, it and ail moiton nodes above ii slump from core to 1 si support grid... 

Construction terial Separator Kesh Support Grid... 

Overall distributor height is approximately 24". The distributor is leveled from a supporting grid, which normally restson the top of the packed bed. The vessel manway is usually located at or above the header elevation. 

Phj sically the redistributions may be a simple and relatively inefficient side wiper as in Figure 9-12 or 9-13 a conventional support grid or plate plus regular distribution plate as used at the top a combination unit similar to Prym support and distributor or a support plate as shown in Figures 9-14 and 9-7D and 7E, a circular plate with holes. 

Combined voidage, support grid plus cloth ... 

Corrosion of the current-conducting elements in the positive electrode, as of the plate support (grid), bus bars, and termi-... 

The final TEM specimen must of course be electron transparent, and it must be either self-supporting or it must rest upon some form of support grid (usually made of copper). The specimen or grid will usually be 3 mm in diameter. 

The inlet air duct, starting at the roof level of the cubicle, leads to the inlet air flap, inlet air filters, and steam heated heat exchanger coils to heat the inlet air. This heated air is directed through a 1/2 supporting grid and 100 mesh screen on the bottom of the product container. 

Difficulties in microtomy include the presence of Si, Cl, and sometimes S in the embedding resin which may interfere with the elements under analysis failure to retain the particle within the epoxy and drift of the section with respect to the support grid. Even when these problems are minimized, it requires patience to survey many grids to find an area to analyze that relates to the catalyst surface, pore structure, defect structure, etc. 

The pressure drop for the produced carrier or catalyst is measured in the setup shown in Fig. 10. An adjustable flow rate of 300-700 Nm3/h ambient air is supplied by a blower and passed downwards through a bed of catalyst in a long tube. The diameter of the bed is 0.39 m, which is well above the minimum of 10 pellet diameters required for satisfactory reproduction of the void fraction observed in a large fixed bed. The catalyst is poured into the tube from the top and the bed may subsequently be settled by applying a reproducible tapping or vibration to the tube. Since the latter reduces the void and increases the pressure drop, it is important that the catalysts are loaded and vibrated in the same way in order to get comparable results. The pressure drop without catalyst should be checked in order not to introduce errors from the support grid or measuring taps. 

Support grid—>fibrous pad—>filter paper—>gel—>nitrocellulose membrane—>filter paper—>fibrous pad—>support grid (see Note 10). 

Figure 3.33. An EDX image showing the composition of a well-ordered CuMn2 spinel catalyst. (Sample on AL support grid.)...

Figure 5.18. (a) and (b) show convergent-beam ED (CBED) patterns in the [001] and [111] zone-axis orientation with the lattice constants confirming that the particles are pure Pd. (c) EDX image from Pd -h support in (b). The Cu line is due to fluorescence from the Cu support grid for the sample. 

Figure 5.29. In situ polymerization in wet-ETEM (a) Co-Ru/titania catalyst (m) in HMD and adipic acid liquids on support grid (G) (b) in situ polymerization to polyamide (p) at 188 °C.

A corrosion allowance is acceptable for the shell and support grids. Other wetted parts should have the ability to withstand corrosion,... 

Fluidized bed reactors typrcally are vertical cylindrical vessels equipped with a support grid and feed sparger system for adequate fluidization and feed distribution, internal cooling coils for heat removal, and either external or internal cyclones to minimize catalyst carryover. Fluidizauon of the catalyst assures intimate contact between feed and product vapors, catalyst, and heat-transfer surfaces, and results in a uniform temperature within the reactor. Reaction heat can be removed by generating steam within the cooling coils or by some oilier heat-transfer medium. 

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