Reactor horizontal tubular

Metal coupons were inserted at various positions in the horizontal tubular reactor. The coupons had two types of surfaces an Incoloy 800 surface and an aluminized Incoloy 800 surface. To prepare these coupons, flat pieces of Incoloy 800 were aluminized (or alonized) by the Alon Processing, Inc. of Tarentum, PA. In this process, gaseous aluminum was contacted with the Incoloy 800, and aluminum diffused into the surface. The alonized samples as received from Alon Processing were cut in small coupons so as to expose an Incoloy 800 surface which was cleaned and polished before use. 

Figures 4 and 5 indicate that the types of coke formed on Incoloy 800 as ethylene and propylene, respectively, were contacted with an Incoloy 800 surface at various temperatures and at slightly different conversion levels. In these experiments, the Incoloy 800 coupons were positioned at different positions in the horizontal tubular reactor. The residence time of gases in the reactor was about 7, 10, 15, and 25 sec by the time the gases reached the coupon. The temperature of each location was about 460°, 560°, 600°, and 565°C, respectively. The cokes...

Figure 3.29. Graphic representation of the formal macroapproach to kinetic modeling of yeast metabolism, showing the dependence of yield coefficient lxis respectively maximum product concentration on initial glucose concentration in batch cultures. Compared are a conventional stirred tank (curve B) and a horizontal tubular loop reactor with mechanical agitation and aeration (curve A), both working at constant /cLiU-value (700 h" ). (Adapted from A. Moser, 1977a.)...

In continuous industrial free-radical polymerization processes, many different types of reactors are used [1]. They are continuous-flow stirred tank reactors, tower reactors, horizontal linear flow reactors, tubular reactors, and screw reactors. In some processes, different types of reactors are used together in a reactor train. In stirred tank reactors, no spatial concentration and temperature gradients exist, whereas in linear flow or tubular reactors, concentration and temperature vary in the direction of flow of the reacting fluid. Specially designed reactors such as screw reactors or extruder reactors are also used to produce specialty vinyl polymers. In this chapter, some important characteristics of continuous reactors used in industrial free-radical polymerization processes are discussed. 

FIG. 23-25 Typ es of industrial gas/Hqiiid reactors, (a) Tray tower, (h) Packed, counter current, (c) Packed, parallel current, (d) Falling liquid film, (e) Spray tower, if) Bubble tower, (g) Venturi mixer, h) Static in line mixer, ( ) Tubular flow, (j) Stirred tank, (A,) Centrifugal pump, (/) Two-phase flow in horizontal tubes. 

There are two known types of reactors with mechanical agitation, vertical (or tubular) and horizontal. 

Tubular Reactors In a tubular or pipeline reactor, gas and liquid flow concurrently A variety of flow patterns, ranging from a small quantity of bubbles in the liquid to small quantities of droplets in the gas, are possible, depending on the flow rate of the two streams. Figure 19-26/ shows the patterns in horizontal flow those in vertical flow are a little different. 

Depending on the gas and liquid residence times required, the reactor could be operated horizontally or vertically with either downflow or upflow. Weikard (in Ullmann, Enzyklopaedie, 4th ed., vol. 3, Verlag Chemie, 1973, p. 381) discusses possible reasons for operating an upflow concurrent flow tubular reactor for the production of adipic acid nitrile (from adipic acid and ammonia). The reactor has a liquid holdup of 20 to 30 percent and a residence time of 1.0 s for gas and 3 to 5 min for liquid. 

Extending the equipment, the authors (Beale et al., 2005) recently added energy dispersive X-ray absorption spectroscopy (XAS). Raman and UV-vis spectra are recorded by illuminating opposite sides of a catalyst bed in a vertical tubular reactor and detecting the scattered and reflected light as described above. XAS is performed in the same horizontal plane but in transmission and with the beam orthogonal to the incident radiation of the other two methods. Example spectra were recorded for samples at 823 K. A combination of UV-vis (fiber optics) and XAFS spectroscopy for investigation of solids has also been described by Jentoft et al. (2004), who reported UV-vis measurements of samples at 773 K. 

Chemical vapor deposition is a key process for thin film formation in the development and manufacture of microelectronic devices. It shares many kinetic and transport phenomena with heterogeneous catalysis, but CVD reactor design has not yet reached the level of sophistication used in analyzing heterogeneous catalytic reactors. With the exception of the tubular LPCVD reactor, conventional CVD reactors may be viewed as variations on the original horizontal reactor. These reactors have complex flow fields and it is consequently difficult to control and predict the effect of operating conditions on the film thickness and composition. 

Experiments with ethylene, acetylene, propylene, and butadiene were made using a 1.27 cm i.d. tubular reactor such as used by Tsai and Albright (14) or Brown and Albright (15). This reactor was inserted in a horizontal position in an electrical resistance furnace. 

The most common type of tubular flow reactor is the single-pass cylindrical tube. Another type is one that consists of a number of tubes in parallel. The reactor(s) may be vertical or horizontal. The feed is charged continuously at the inlet of the tube, and the products are continuously removed at the outlet. If heat exchange with surroundings is required, the reactor setup includes a jacketed tube. If the reactor is empty, a homogeneous reaction—one phase present—usually occurs. If the reactor contains catalyst particles, the reaction is said to be heterogeneous. 

The flow reactor used in most experiments is described elsewhere [5]. Briefly, it consists of a horizontal quartz tube encased in a divisible tubular furnace. The catalyst is sealed in the middle of the heated zone with quartz wool and the gases are introduced via mass flow controllers. Reactants and products are analysed on-line with respect to N2O, CO, CO2 (IR), and NO, NO2 (chemiluminescence)... 

A stainless steel-lined tubular pressure reactor having an internal volume of about 350 mL and equipped with a thermocouple well and gas inlet was charged with 210 g. (1.36 moles) of freshly distilled carbon tetrachloride, 35 g. of water, and 0.47 g. (0.00194 mole) of benzoyl peroxide ( Lucidol ). The reactor was evacuated, pressured to 500 Ib./sq. in. with ethylene, and placed horizontally in a shaking box equipped with a heater. When the temperature of the reaction mixture was... 

Fig. 30. Contacting patterns and contactor types for gas-liquid-solid reactors, (a) Co-current downflow trickle bed. (b) Countercurrent flow trickle bed. (c) Co-current downflow of gas, liquid, and catalyst, (d) Downflow of catalyst and co-current upflow of gas and liquid, (e) Multi-tubular trickle bed with co-current flow of gas and liquid down tubes with catalyst packed inside them coolant on shell side, (f) Multi-tubular trickle bed with downflow of gas and liquid coolant inside the tubes, (g) Three-phase fluidized bed of solids with solids-free freeboard, (h) Three-phase slurry reactor with no solids-free freeboard, (i) Three-phase fluidized beds with horizontally disposed internals to achieve staging, (j) Three-phase slurry reactor with horizontally disposed internals to achieve staging, (k) Three-phase fluidized bed in which cooling tubes have been inserted coolant inside the tubes. (1) Three-phase slurry... 

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