Reactors distributor plate

Commercial chlorohydrin reactors are usually towers provided with a chlorine distributor plate at the bottom, an olefin distributor plate about half way up, a recirculation pipe to allow the chlorohydrin solution to be recycled from the top to the bottom of the tower, a water feed iato the recirculation pipe, an overflow pipe for the product solution, and an effluent gas takeoff (46). The propylene and chlorine feeds are controlled so that no free gaseous chlorine remains at the poiat where the propylene enters the tower. The gas lift effect of the feeds provides the energy for the recirculation of the reaction solution from the top of the tower. 

The distributor plate is sandwiched against the catalyst wafer using a gasket of polymer or graphite and the volume above each catalyst patch defines a reaction volume. A cross-section view of one of the 256 reaction/detection channels is shown below (Fig. 3.8). Feed gas enters the reaction volume from the side. For residence times greater than 100 ms the reactor behaves as a difFusionally mixed... 

Slurry Reactors Slurry reactors are akin to fluidized beds except the fluidizing medium is a liquid. In some cases (e.g., for hydrogenation), a limited amount of hydrogen may be dissolved in the liquid feed. The solid material is maintained in a fluidized state by agitation, internal or external recycle of the liquid using pipe spargers or distributor plates with perforated holes at the bottom of the reactor. Most industrial processes with slurry reactors also use a gas in reactions such as chlorination, hydrogenation, and oxidation, so the discussion will be deferred to the multiphase reactor section of slurry reactors. 

Figure 3. Trickle-bed reactor. Key A, gas b, liquid c, liquid distributor d, thermocouple e, alumina particles f, jacket g, catalyst h, glass beads i, gas distributor j, packing supporting plate K distributor plate.

The reactor distributor was made from a 50 mm thick fixed bed of 5 mm diameter pebbles supported on a perforated plate with the benzene introduced at its centre. Nickel particles (0.53 mm diameter) to a depth of 25 mm on top of a second perforated plate formed a second fixed bed and completed the distributor. The reactor was completely insulated with glass wool. 

We next develop the mass balance equations for the gaseous reactant (oxygen) and the product (sulfur dioxide). The gas flow in the reactor is assumed to be in plug flow and hence the concentration of these gases will depend only on the height H, in the bed above the distributor plate. The rate of consumption of oxygen by reactions 1, 2 and 3 can be obtained from Eqs. 43 and 80 and the stoichiometry of these reactions. We will first examine Eq. 43 which may be rewritten as follows after appropriate substitutions. 

The DWSA installation can be divided into two main parts. The first part consists of an air preheater, fluidised bed reactor, solid fuel dosing vessel with on-line mass determination system and a hot gas cleaning section, containing a cyclone and a ceramic candle filter (Schumacher type). In the fluidised bed reactor the solid fuel is gasified with air to produce a low calorific value (LCV) gas that is cleaned of fly ash and unreacted solid carbonaceous material. Air and also additional nitrogen can be preheated and is introduced into the reactor by four nozzles just above the distributor plate. The reactor is electrically heated in order to maintain a constant temperature over bed as well as freeboard section. The solid fuel is fed into the bed section in the bottom part Just above the distributor by a screw feeder from beside. The hot gas cleaning section ensures a good gas-solid separation efficiency, with filter temperatures of about 500 C. 

The reactor is constructed of Inconel 600 alloy and has an international diameter of 15 cm at the bottom and 30 cm in the free-board area. Fluidizing gas (air and steam mixture) is introduced through a specially designed Inconel distributor plate. The reactor is insulated with Kaowool ceramic fibre. The bed materials consist of a graded sand fraction of 60—80 mesh. 

An example of a mapping from the equipment representation to the thermodynamic state representation is shown in Fig. 5. It represents an isothermal vertical packed-bed catalytic reactor equipped with temperature and pressure sensors, an explosion vent, and a distributor plate. Notice that the equipment and sensors are not associated with the state representation. They are contained in the base representation and reside in the process description at the equipment level. As discussed earlier, flow, work, heat, and mass interactions are all modeled independently. This allows us to evaluate independently the effect of these processes. Independent evaluation assists in the identification, evaluation, and assessment of event pathways leading to hazardous states. 

Gas Distributor. The gas distributor plate at the bottom of the reactor must introduce gas uniformly, prevent hole-plugging or weeping of solids, promote good gas-solid contacting, and support the weight of... 

The H-Oil reactor (Fig. 21) is rather unique and is called an ebullated bed catalytic reactor. A recycle pump, located either internally or externally, circulates the reactor fluids down through a central downcomer and then upward through a distributor plate and into the ebullated catalyst bed. The reactor is usually well insulated and operated adiabatically. Frequently, the reactor-mixing pattern is defined as backmixed, but this is not strictly true. A better description of the flow pattern is dispersed plug flow with recycle. Thus, the reactor equations for the axial dispersion model are modified appropriately to account for recycle conditions. 

The coal is crushed in a hammer mill, dried, and then screened to —16 + 80 mesh. About 500 lb. of coal are charged to a hopper, which is connected at the bottom to the pretreater by a screw feeder. The feed enters the pretreater about 6 inches above the distributor plate. Feed rates of up to 100 lb./hr. can be attained. A 3-in. diameter overflow pipe controls the bed height. The overflow collects in a receiver and is periodically dumped into drums. Fines from the bed were originally returned to the bed by an internal cyclone with a dipleg sealed in the bed, but tar tended to build up in the cyclone and caused the reactor pressure to increase. At present, a heated external cyclone with a collector pot is installed and operates much more smoothly. 

Nitrobenzene [98-95-3]y C H N02 is produced by the nitration of benzene with a mixture of nitric and sulfuric acid. A process for the manufacture of aniline [62-53-3] C HyN, from nitrobenzene is shown in Figure 3 (16). Nitrobenzene, which contains less than 10 ppm nitrothiophene, a catalyst poison, is fed to a vaporizer where it is vaporized. As the gaseous nitrobenzene leaves the vaporizer, it is mixed with a 200% excess of hydrogen gas. The gaseous mixture then passes upward through a porous distributor plate into the reduction chamber of the fluidized-bed reactor which contains the... 

The reactor is cylindrical and made of 316 stainless steel with an internal diameter of 0.028 m, an external diameter of 0.030 m. The catalyst bed is located on a distributor plate with... 

In transitioning between incompatible Ziegler— Natta catalysts and metallocene catalysts in a fluidized-bed gas-phase process, polymerization of the first catalyst must be fully stopped before introducing the second catalyst. Small amounts of a catalyst killer such as water or methanol, either injected directly into the gas stream or added as wet silica, are introduced to deactivate the catalyst in the reactor irreversibly. The second catalyst is added after adjustment of the feed streams. Addition of CO above and below the distributor plate has also been used. Leftover catalyst in addition vessels can be deactivated by heat treatment, followed by exposure to air. ... 

Additional evidence indicating lack of fluidization of the large gin trash pellets appeared when the bottom flange of the reactor was removed. With manure, sawdust, mesquite, and com stover, the reactor was empty at the conclusion of each run. With pelleted cotton gin trash, a buildup of ash was found on the distributor plate. This means that the pelleted gin trash could not be used in the SGFM reactor on a continuous basis. 

Some fluid bed reactors are operated without a distributor plate. The base of the reactor is simply constructed in the shape of an inverted cone. The high linear velocity at the base of the cone prevents blocking of the gas inlet by particles of the solid being fluidized. 

The fluidised bed reactor is a vertical pressure vessel with a total height of up to 40 m. A fluidised bed of polymer particles in gaseous ethylene is maintained by a recycle compressor. The ethylene recycling gas enters the reactor through a distributor plate at the bottom to achieve an even gas flow over the entire cross-section and to hold the particles when the gas flow is turned off. In the characteristically conical upper part of the reactor, the gas velocity decreases with the increasing diameter of the reactor to keep the particles in the fluidised bed. The gas leaves the reactor at the top. It is cleaned from entrained particles by a eyelone, the reaction heat is removed by a recycle gas cooler and the gas is then routed back to the bottom reactor inlet. 

The pol5mier and associated gases are discharged from the reactor directly above the distributor plate with time-controlled valves passing through a cyclone into a tank filled with nitrogen to remove residual monomers from the polymer. With modem catalysts, neither the catalysts nor the atactic pol5miers have to be extracted. 

In the process, air is introduced uniformly into the bottom of the reactor via a distributor plate. The propylene and ammonia are introduced into the fluidized bed above the distributor plate via a separate sparger. The design of these gas distribution systems has evolved over the years improving the reactor yield (Ohta and Yokura, 1996.)... 

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