Catalyst support grids

Nitriding of pipes and catalyst-support grids are usually encountered in ammonia plants. The nitriding effect is more pronounced in low-alloy steels... 

Vinyl chloride monomer production (reformed catalyst tube) Nitric add production (NH3 oxidation reactor and catalyst support grid)... 

Catalyst support grids and columns Cast iron ... 

Whether the beams extend above or below the support level is matter of application. Both methods have their pros and cons. Basically, the method of support is determined by the designer to accommodate the space inside the vessel as well as the process function of the bed or tray that the beams are supporting. If the beam extends up into the bed, then a certain amount of media is displaced and removal of media is more difficult. Conversely, in the case where the beams support a tray, then having the beams extend above the tray may impose restrictions on flow. Beams for catalyst support grid (CSG) applications almost always extend up into the bed to minimize the length of the vessel. 

Thermowell Support 3" Layer of 1/8 Inerts 3 Layer of 1/4" Inerts Catalyst Support Grid and Beams Upper Quench and Splash Trays Lower Distribution Tray... 

Catalyst support Multiple beds are often utilized in reactors that have high temperature rises or would benefit from re-distribution of the reactants. These reactors would have catalyst support grids and beams to carry the weight of each catalyst bed. 

Nitric acid production ammonia oxidation reactor and catalyst support grid up to 950 °C Nitriding/oxidation... 

Insulating cans in ammonia reformers and catalyst support grids used in nitric acid production... 

Figure 2 Experimental setup for liquid phase reaction with ACC catalysts (the grid supporting the ACC is partially lifted out of the autoclave).

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. 

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

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.

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. 

Fig. 7.1. Bed of catalyst pieces for oxidizing S02 to S03. It is circular, 7 to 17 m diameter. Industrial S02 oxidation is done in a converter of 3 to 5 such beds, Figs. 7.6 and 7.7. Downward gas flows are 25 Nm3/minute per m2 of top surface. Active catalyst consists of a molten V, K, Na, Cs, S, O phase supported on a solid porous silica substrate, Chapter 8. A top layer of silica rock holds the catalyst in place. A bottom layer prevents the catalyst from sticking to the stainless steel support grid.

In addition the electrodes contain a metal grid as current collector. As different partial processes are combined in the operation of a gas-fed electrode its design demands a optimization with respect to its parameters. The operation can be tuned to the electrolyte/reactant system by the choise of composition (binder, catalyst support carbon. 

Support Grid Grating or some other type of support through which vapor or liquid can pass. Used to support tower packing (catalyst, raschig rings, etc.). 

Provision of Cl support grids. Cl columns, and Cl partition plates (with cover of a refractory layer) for the catalyst passes for smaller capacity plants. Larger plants have dome shaped structures for catalyst supports. 

Materials of construction of reactors and agitators, protective lining of reactor, and catalyst bed support grids shall not react with the reactants being processed. 

To combine the advantages of packed-bed and catalytic wall microreactors, catalytic bed microreactors were proposed recently. In this novel reactor design, the catalyst is applied on metallic filaments or wires which are incorporated in a microreactor, leading to a low pressure drop and a nanow residence time distribution [87-89]. By insertion of metallic wires a uniform gas distribution and a reduced risk of temperature gradients is obtained. However, similarly to catalytic wall microreactors, an increase in the specific surface area of the grid or wire is required. In addition to metallic wires and grids, modified ceramic tapes can also be used as a catalyst support [90]. 

The converter tower should be made of stainless steel 316. The catalyst mass on each of the 4 beds is "sandwiched" between two layers of quartz the top layer ensures proper gas distribution to the underlying catalyst bed and the underlayer prevents catalyst pellets falling through the stainless steel supporting grid. There is a manhole above each bed, used for catalyst inspection and catalyst replacement. Ideally these manholes should be accessible by a permanent scaffolding construction with a ladder and a small platform to each bed position. Thermocouples are located after entry and at the exit of each of the converter beds. The operation of the converter is controlled by the entry temperature of each bed. It should be verified that each thermocouple is correctly positioned and in good condition. 

The oxychlorination reactor is a vertical cylindrical shell made of carbon steel with a support grid/air sparger system and internal cooling coils. Internal or external cyclones are used to minimize catalyst carryover. The reactor internal parts are made from corrosion-resistant alloy. The reactor has many design features depicted in Fig. 1. 

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