Reactor vertical shaft

The R D requirement exists solely in the production of synthesis gas from wood, since the catalytic production of methanol is well developed. The vertical shaft counter flow reactor developed by Union Carbide for municipal waste... 

Different types of reactors are utilized for a wide variety of pyrolysis applications, including processing of waste plastics. The worldwide waste plastic pyrolysis systems utilize the fixed-bed designs of vertical shaft reactors and dual fluidized-bed, rotary kiln and multiple hearth reactor systems. The type of reactor used is chiefly based on material to be pyrolyzed and expected products from the pyrolysis. Stainless steel shaking type batch autoclave and stainless steel micro tubular reactors have also been used extensively [14]. Fluidized-bed reactors have been extensively used in producing raw petrochemicals from the pyrolysis of waste plastics [22, 24]. 

It is important to maintain correct levels in the hoppers into which the elevators discharge. Too high a level causes spillage of catalyst, and too low a level results in insufficient pressure in the reactor seal leg. Hoppers in some units are equipped with a continuously rotating vertical shaft with paddles which ride on the surface of the catalyst the position of the upper end of the shaft is communicated to the control room by means of a pneumatic transmitter (185,191). 

The most popular type of gasification furnace in Europe is the vertical shaft gasifier, used in the Andco-Torrax, Saarberg Fernvarme and Pyrogas process. Pyrolysis processes are often conducted in an indirectly heated rotary kiln reactor, e.g. in the Kiener, GMU or Krauss-Maffei process. Fluidized bed reactors are used at the universities of Hamburg, Eindhoven and Brussels and thus seem more popular in academic than in industrial spheres. 

In U.S. plants hydrofluorination is carried out in two stirred fluidized-bed reactors in series, with counterflow of solids and gases. The bed to which UO2 is fed and from which exhaust gases are discharged runs at 300°C, partially converts UO2 to UF4, and reduces the HF content of the effluent gases to around 15 percent. The bed to which anhydrous HF and the partially converted UO2 are fed runs at 500°C and converts more than 95 percent of the UO2 to UF4. To prevent caking of the fluidized beds, it has been found necessary to provide each reactor with a vertical-shaft, slow-speed stirrer to scrape the reactor walls. Production rates around 700 to 900 kg/h are obtained in 0.75-m-diameter reactors. Effluent gases are filtered to remove entrained solids, cooled to condense aqueous HF, and scrubbed to remove the last traces of HF. 

Production of ZrCl4. Zirconium oxide from the hafnium-separation step was mixed with carbon black, dextrin, and water in proportions 142 Zr02, 142 C, 8 dextrin, and 8 water. The mixture was pressed into small briquettes (3.8 X 2.5 X 1.9 cm) and dried at 120°C in a tray drier. The oxide briquettes were charged to the reaction zone of a vertical-shaft chlorinator lined with silica brick. The charge was first heated by carbon resistance strips until it became conductive. During production, the bed temperature was maintained at 600 to 800 C by an electric current passed directly through the bed. After steady conditions were reached, a reactor 66 cm in diameter produced about 25 kg ZrCLt/h. The ZrCU was condensed from the reaction products in two cyclone-shaped aftercondensers in series, and the chlorine off-gas was removed in a water scrubbing tower. 

The agitator shaft is inclined from 0 to 45 with the vertical, and multiple impellers are used with longer reactors. 

The continuous polystyrene process which was commercialized successfully in 1952 (2) is illustrated schematically in Fig. 16. It is characterized by three vertical elongated reactors in series, the contents of which are gently agitated by slowly revolving rods mounted on an axial shaft. Temperature control is provided by horizontal banks of cooling tubes between adjacent agitator rods. Such a reactor, called a "stratifier-... 

The deep shaft reactor is a very tall IL airlift reactor that has vertical partitions, and is built underground for the treatment of biological waste water. This reactor is quite different in its construction and performance from the simple IL airlift reactor with a vertical partition. In the deep-shaft reactor, air is injected into the downcomer and carried down with the flowing liquid. A very large liquid depth is required in order to achieve a sufficiently large driving force for liquid circulation. 

Reactor Coolant Pumps. As indicated by Fig. 8, four reactor coolant pumps are used, two for each steam generator, The pumps are vertical, single-bottom-suction, horizontal-discharge, motor-driven centrifugal units. The pump impeller is keyed and locked to its shaft, A complex system of... 

Fig. 10. Vertical reactor with a heat exchange element in the form of a tube bundle 1, 2, 5 - heat exchange surfaces 3 - immobile board with shelves 4 - redistribution grate with shelves 6 - redistribution grate with shelves 7 - conical bottom 8 - shaft.

Fig. 11. Vertical four-section reactor with rotating grates and immobile perforated grate 1 - casing 2 - heat exchanger 3 - redistribution grates 4 - key 5 -shaft 6 - perforated grate for preliminary gas distribution 7 - separation chamber.

Fig. 19. Vertical cross-section of the wiper-blade reactor. A, Sealing arrangement B, gas phase C, rotor D, sealing E, bearing F, excess gas flow G, gas collected from the liquid exit H, overflow vessel I, liquid exit J, rotor blades K, gas feed L, adjustable shaft M, baffles N, reactor shell O, cooling jacket P, cooling water feed and exit Q, sampling port R, grooves S, liquid phase T, gas-liquid interface U, top and bottom plates and V, liquid feed. (After Manor and Schmitz, 1984 also from Chaudhari et al., 1986, by courtesy of Marcel Dekker, Inc.).

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