Cylindrical vessels

Tubular reactors, as previously stated, are also advantageous for high-pressure reactions where smaller-diameter cylindrical vessels can be used to allow thinner vessel walls. Tubular reactors should be avoided when carrying out multiphase reactions, since it is often difficult to achieve good mixing between phases. 

The experimental activity has been carried out on a cylindrical vessel whose capacity is 50 litres and made from steel 3 mm. thick. 

Carbon disulfide [75-15-0] is a clear colorless liquid that boils at 46°C, and should ideally be free of hydrogen sulfide and carbonyl sulfide. The reaction with alkaU cellulose is carried out either in a few large cylindrical vessels known as wet chums, or in many smaller hexagonal vessels known as dry chums. In the fully continuous viscose process, a Continuous Belt Xanthator, first developed by Du Pont, is used (15). 

The vertical cylindrical vessel of the pressure version of the Moore filter developed in France for the sugar industry, which houses a set of radially arranged leaves, is twice the height of the leaves. This allows the leaves to be raised, rotated, and lowered into the different compartments in the bottom half of the vessel. Positive air pressure must be maintained throughout the operation to prevent cake faH-off, and the cake is blown off the leaves by air blowback. 

Horizontal Vessel, Vertical Leaf Filters. In a cylindrical vessel with a horizontal axis (Fig. 18), the vertical leaves can be arranged either laterally or longitudinally. The latter, less common, arrangement may be designed as the vertical vessel, vertical leaf filters but mounted horizontally. Its design is suitable for smaller duties and the leaves can be withdrawn individually through the opening end of the vessel. 

Horizontal Vessel, Horizontal Leaf Filters. These filters consist of a horizontal cylindrical vessel with an opening at one end (Fig. 19). A stack of rectangular horizontal trays is mounted inside the vessel the trays can usuaUy be withdrawn for cake discharge, either individuaUy or in the whole assembly. The latter case requires a suitable carriage. One alternative design aUows the tray assembly to be rotated through 90° so that the cake can faU off into the bottom part, designed in the shape of a hopper and fitted with a screw conveyor. 

The American version of the dynamic filter, known as the Artisan continuous filter (Fig. 30), uses such nonfiltering rotors in the form of turbine-type elements. The cylindrical vessel is divided into a series of disk-type compartments, each housing one rotor, and the stationary surfaces are covered with filter cloth. The feed is pumped in at one end of the vessel, forced to pass through the compartments in series, and discharged as a thick paste at the other end. At low rotor speeds the cake thickness is controlled by the clearance between the scraper and the filter medium on the stationary plate, while at higher speeds part of the cake is swept away and only a thin layer remains and acts as the actual medium. 

The cementation of gold and the purification of the ziac electrolyte ate usually carried out ia cylindrical vessels usiag mechanical agitation. The cementation of copper is carried out ia long narrow tanks called launders, ia rotating dmms, or ia an iaverted cone precipitator (see Copper). 

The lauter tun is a cylindrical vessel provided with an extra perforated bottom about 1—10 cm above the real bottom. Using the lauter tun the wort is separated and sparged through a filter bed built up by the husks deposited on the perforated bottom. The yield is 3—10 brews per 24 h. 

Rod and ball mills are cylindrical vessels into which the ore, water, and steel balls or steel rods, called grinding media are charged. The vessels rotate on horizontal axes to cascade the ore and grinding media and thus grind the ore. Typical hall-mill sizes range from 2.5 m in diameter and 3 m in length, driven by a 187-kW motor, up to ca 5 m in diameter and 7 m in length with a 3000-kW drive. 

Most distillations conducted commercially operate continuously, with a more volatile fraction recovered as distillate and a less volatile fraction recovered as bottoms or residue. If a portion of the distillate is condensed and returned to the process to enrich the vapors, the Hquid is called reflux. The apparatus in which the enrichment occurs is usually a vertical, cylindrical vessel called a stiU or distillation column. This apparatus normally contains internal devices for effecting vapor—Hquid contact the devices may be categorized as plates or packings. 

Radius of cylindrical vessel Reynolds number Schmidt number... 

External-Cake Tubular Filters Several filter designs are available with vertical tubes supported by a filtrate-chamber tube sheet in a vertical cylindrical vessel (Fig. 18-115). The tubes may be made of wire cloth porous ceramic, carbon, plastic, or metal or closely wound wire. The tubes may have a filter cloth on the outside. Frequently a filter-aid precoat will be applied to the tubes. The prefilt slurry is fed near the bottom of the vertical vessel. The filtrate passes from the outside to the inside of the tubes and into a filtrate chamber at the top or the bottom of the vessel. The sohds form a cake on the outside ofthe tubes with the filter area actually increasing as the cake builds up, partially compensating for the increased flow resistance of the thicker cake. The filtration cycle continues until the differential pressure reaches a specified level, or until about 25 mm (1 in) of cake thickness is obtainea... 

Laminar or power law velocity distribution in which the linear velocity varies with radial position in a cylindrical vessel. Plug flow exists along any streamline and the mean concentration is found by integration over the cross section. 

Rocket Fragment from a Cylindrical Vessel Pressurized... 

Large, Single Fragment Ejected from Cylindrical Vessel... 

N Length of cylindrical vessel forming rocketing tub fragment... 

Single Small Fragment Ejected from a Cylindrical Vessel Pressurized with an Inert Ideal Gas... 

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