Reactor vertical tube

The remaining reactors are of similar design as shown in Fig. 22. These are bottom fed, completely filled vessels. There is a central upward pumping screw surrounded by a draft tube through which coolant circulates. The reactant syrup descends in the annular space between the draft tube and the jacketed reactor wall. In this annular space is a circular rank of manifolded vertical tubes with circulating coolant... 

Traditionally, the steam reforming reactor has a tubular design in which vertical tubes, loaded with catalyst, are surrounded by furnaces to supply the heat required for the strongly endothermic process, see Fig. 8.2. Combustion of natural gas supplies the heat to the tubes. 

Kozlov, B. K., 1954, Forms of Flow of Gas-Liquid Mixtures and Their Stability Limits in Vertical Tubes, Zh Tekh. Fiz. 24( 12) 2285—2288. Transl. RJ-418, Assn. Tech. Service, East Orange, NJ. (3) Kramer, A. M., 1958, Boiling Water Reactors, Addison-Wesley Pub. Co., New York, (4)... 

A typical commercial reactor consists of a vertical tube, up to 10 m in height, into the top of which the monomer is fed continuously. As polymerization proceeds, the increasingly viscous polymer solution travels down the column. Molten polymer is drawn from the bottom of the reaction tube and is subsequently cooled and chopped into pellets. The final manufacturing stage consists of exposing the pellets to a strong vacuum at a slightly elevated temperature to remove residual monomer and water. 

Phthalic anhydride Naphthalene is oxidized by air to phthalic anhydride in a bubbling fluidized reactor. Even though the naphthalene feed is in liquid form, the reaction is highly exothermic. Temperature control is achieved by removing heat through vertical tubes in the bed to raise steam [Graham and Way, Chem. Eng. Prog. 58 96 (January 1962)]. 

These parts are used in fluidized beds for various purposes. For example, gas distributors and various types of baffles are installed to decrease the size of the bubbles. Moreover, draft tubes are used to enhance gas or solid circulation. Other devices such as horizontal baffles limit circulation and backmixing of solids and gas. Horizontal or vertical tubes are used for heat management. Devices used to control or improve fluidization behavior, to improve fluidization of cohesive particles or to achieve solids recovery are within the various internals met in fluidized bed reactors (Kelkar and Ng, 2002). Immersed tubes in small diameter beds may lead to slugging. Furthermore, attrition of particle breakage may change the size distribution and possibly change the fluidization behavior. 

Figure 7.11b shows an EL airlift reactor, in schematic form. Here, the downcomer is a separate vertical tube that is usually smaller in diameter than the riser, and is connected to the riser by pipes at the top and bottom, thus forming a circuit for liquid circulation. The liquid entering the downcomer tube is almost completely degassed at the top. The liquid circulation rate can be controlled by a valve on the connecting pipe at the bottom. One advantage of the EL airlift reactor is that an efficient heat exchanger can easily be installed on the hquid loop hne. 

In a falling-film reactor composed of several vertical tubes, on the heated walls of which the reaction medium streams.70... 

Fixed-bed reactors resemble multitube heat exchangers, with the catalyst packed in vertical tubes held in a tubesheet at top and bottom. Reaction heat can be removed by generating steam on the shell side of the reactor or by some other heat-transfer fluid. However, temperature control is more difficult in a fixed-bed than in a fluulized-bed reactor because localized hot spots tend to develop in the tubes. 

The research at MIT has been done in the cold-wall vertical tube reactor shown in Figure 14. The wafer is aligned almost parallel to the flow on a vertical silicon carbide-coated susceptor. The wafer is heated by optical radiation from high-intensity lamps to a temperature of 775°C. Silane was introduced... 

In the United States the Stengel process is used to produce anhydrous ammonium nitrate directly. In this process ammonia and 58% nitric acid are preheated with fresh steam and fed into a packed vertical tube reactor at 3.5 bar and 240°C. The mixture of NH4NO3 and steam is expanded into a vacuum in a centrifugal separator. After stripping with hot air, a 99.8% NH4NO3 melt is discharged onto a cooled steal belt, solidified and then broken up or granulated295. 

The reaction is carried out at a bed temperature of 400-500 °C and a gas contact time of 1-15 s [76] or 5-20 s [2]. Figure 17 is a schematic of the reactor. Air is fed to the bottom of the fluidized-bed vessel. The reactants ammonia and propene are fed in through a separate distributor (b). Catalyst regeneration by carbon burnoff occurs in the space between the air distributor and the feed-gas distributor. The heat of reaction is removed by bundles of vertical tubes (a) inside the bed (horizontal tubes are used in other designs [77]). 

RHENIUM PENTACHLORIDE AND VOLATILE METAL CHLORIDES BY DIRECT CHLORINATION USING A VERTICAL-TUBE REACTOR... 

The synthesis loop consists of a recycle compressor, feed/effluent exchanger, methanol reactor, final cooler and crude methanol separator. Uhde s methanol reactor is an isothermal tubular reactor with a copper catalyst contained in vertical tubes and boiling water on the shell side. The heat of methanol reaction is removed by partial evaporation of the boiler feedwater, thus generating 1-1.4 metric tons of MP steam per metric ton of methanol. Advantages of this reactor type are low byproduct formation due to almost isothermal reaction conditions, high level heat of reaction recovery, and easy temperature control by... 

Fig. 4. Sasol fast-bed synthesis reactor. Each of the two cooling sections comprises two tube sheets vertical tubes within which gas and catalyst move upward and a pool of cooling oil, surrounding the tubes.

Recently, Sheinson and co-workers [134] have been able to show the presence of small amount of methyl hydroperoxide in an acetaldehyde cool flame stabilized in a vertical tube reactor. 

Optimum size distribution is important for a fluid bed reactor (Bergoug-nou). Models based on bubbles are not yet capable of predicting the wall effect (Wen). Vertical baflles are most effective in breaking up large bubbles (Volk). The height of the bottom ends of vertical tube bundles above the grid will set the attainable bubble size at the bottom of the bundle. The bundles then essentially maintain the bubble size (Zenz). Horizontal perforated baflle plates reduce the mean residence time of elutriable fine particles in a fluidized bed (Buckham). Observations on attrition in cyclones indicate that it is an exponential function of velocity (Tenney). 

Conoco-Phillips Reactor. This reactor is basically a vertical tube in which the HF/hydrocarbon dispersion... 

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