Refractory lined vessels

The basic fluid-bed unit consists of a refractory-lined vessel, a perforated plate that supports a bed of granular material and distributes air, a section above the fluid bed referred to as freeboard, an air blower to move air through the unit, a cyclone to remove all but the smallest particulates and return them to the fluid bed, an air preheater for thermal economy, an auxiUary heater for start-up, and a system to move and distribute the feed in the bed. Air is distributed across the cross section of the bed by a distributor to fluidize the granular soflds. Over a proper range of airflow velocities, usually 0.8-3.0 m/s, the sohds become suspended in the air and move freely through the bed. 

Large sulfuric acid plants are based on spray burners, where the sulfur is pumped at 1030—1240 kPa (150—180 psig) through several nossles iato a refractory-lined combustion chamber. An improved nossle, resistant to plugging or fouling, has been iatroduced (256). The combustion chambers are typically horizontal baffle-fitted refractory-lined vessels. The largest plants ia fertiliser complexes bum up to 50 t/h of sulfur. 

Chromium oxide is mixed with aluminum powder, placed in a refractory-lined vessel, and ignited with barium peroxide and magnesium powder. The reaction is exothermic and self-sustaining. Chromium metal of 97—99% purity is obtained, the chief impurities being aluminum, iron, and silicon (Table 4). Commercial chromium metal may also be produced from the oxide by reduction with silicon in an electric-arc furnace. 

Chromium metal is produced hy thermal reduction of chromium(III) oxide, Cr203 by aluminum, silicon or carbon. The starting material in all these thermal reduction processes are Cr203 which is obtained from the natural ore chromite after the removal of iron oxide and other impurities. In the aluminum reduction process, the oxide is mixed with A1 powder and ignited in a refractory-lined vessel. The heat of reaction is sufficient to sustain the reaction at the required high temperature. Chromium obtained is about 98% pure, containing traces of carbon, sulfur and nitrogen. 

The secondary reformer vessel is a refractory-lined vessel that has an oxygen burner in its top neck and a fixed catalyst bed. Installation of a secondary reformer usually requires significant changes to the CO2 removal system Hydrogen purity can be increased up to 98%. The economics generally depend on a reliable source of low-cost oxygen172. 

The reforming process is completed in the authothermic secondary reformer, which is a refractory lined vessel containing a fixed-bed catalyst. The remainder of the endothermic heat requirement is provided by the combustion of part of the primary reformer effluent directly with air. This allows much higher process temperatures, of the order of 1000°C, to be attained at the secondary reformer exit and consequently low methane slips in the range of 0.2-... 

Nothing much changed in iron or steelmaking for the next 200 years until the Bessemer process was introduced in the mid 1800s. In the Bessemer process, molten iron from the blast furnace was transferred to a separate refractory-lined vessel into which large quantities of cold air were blown to oxidize and remove the carbon. This was made possible by developments in air compression equipment. The modem steel age was bom. The availability of higher-quality, low-cost steel drove rapid expansion of the market for iron and steel and led to a rapid development of several new technologies. 

Basically, a steel ladle is a relatively small, refractory-lined vessel that during preheating behaves very much like a small furnace. Heat transfer from the preheater to the ladle is primarily by convection and radiation. The convection can be described using... 

Autothermal reforming combines partial oxidation and adiabatic steam reforming for conversion of the hydrocarbon feedstock into synthesis gas free of soot and higher hydrocarbons. The ATR reactor design consists of burner, combustion chamber, and catalyst bed placed in a refractory lined vessel, as illustrated in Fig. 10. The hydrocarbon feedstock with steam is reacted with oxygen in a substoichiometric flame, often... 

Vessel engineers must eventually become familiar with refractory materials, techniques, strategies and installation in order to properly specify, analyze and check vendor designs for refractory lined vessels, equipment and components. Refractory lining is utilized as a heat barrier, insulator, or as an abrasion resistant lining, or both. Dual component linings are utilized for insulating and abrasion resistance. 

Examples of vessels that are typically exempted from field testing are large refractory lined vessels such as ECC reactors and regenerators. 

The EHTR concept can conveniently be combined with an existing HSR plant to increase capacity to about 30%. The EHTR reactor is a pressurized-refractory-lined vessel containing reactor tubes fllled with catalyst. These tubes are supported from the bottom tube sheet. The tubes may expand on the top end where they are freely located (Fig. 11). 

The upper refractory lined vessel is continuously fed with high-altunina balls which are heated up by the hot gases. They fall to the lower refractory-hned vessel where the cold air gets pre-heated by taking up heat from the hot material. 

Converter. A refractory-lined vessel supported on trunnions and used for the production of steel by oxidation of the... 

The ATR reactor consists of a burner, a combustion chamber, and a fixed catalyst bed placed in a compact refractory lined vessel [107] as illustrated in Figure 1.18. Irrespective of whether the burner is thermal or catalytic or whether a fixed or a fluidised catalyst bed is used, the product gas will be determined by the thermod5mamic equilibrium at the exit temperature, which in turn is determined by the adiabatic heat balance. 

The exit gas of the steam reformer may be further converted with air/oxygen by autothermic reforming in the presence of a catalyst. The reactor is a refractory lined vessel (Figure 6.2.33) and thus higher temperatures can be applied than in steam reforming. 

Thus, if we specify higher temperatures, we must be able to justify the economic penalty associated with more complicated processing equipment, such as refractory-lined vessels or exotic materials of construction. In addition to the critical temperature of 400°C, there are temperature limits associated with the availability of common utilities for heating and cooling a process streara... 

The feedstock is gasified in an empty, refractory-lined vessel. All gases are fed through a burner. The oxidant is preheated in an exchanger prior to being fed to the burner. The burner and reactor are designed such that this oxygen is intimately mbced with the feedstock. 

For ammonia manufacture, it is necessary to introduce nitrogen into the system. This is done in the second step, as shown in Fig. 28.3, by mixing air with the primary reformer gas in a refractory-lined vessel that contains additional reforming catalyst. The mixing of the air and the primary reformer gas is critical, and specially designed burners are used. The temperature at the point of mixing will reach 1260°C because of the fast reaction of the... 

Secondary reforming is carried out in an adiabatic, refractory-lined vessel. Gas from the primary reformer typically at about 800 °C and containing 8-12 vol% (dry) residual methane is mixed in a burner with preheated air. The partially reacted mixture passes through a bed of catalyst, where the reactions are completed. The gas leaves the reactor at about 1000 °C with a residual methane content of typically 0.3-1.0 vol% (dry). 

The most used refractory lined vessel geometry in industry appears to be the cylindrical refractory lined vessel. In the steel industry, the blast furnace, blast furnace stoves, torpedo cars, steelmaking ladles (7), electric arc furnaces, degasser vessels, and cyclone dust collector are a few examples of cylindrical vessels. In the petrochemical industry, the petrochemical processing vessels are typically cylindrical. Fluid bed reactor vessel walls are typically cylindrical with a spherical vessel top. Many other basic industries use cylindrical refractory lined vessels such as rotary kilns and wood pulp process vessels. 

Other examples of cylindrical lined vessels include blast furnaces, blast furnace stoves, basic oxygen furnaces, torpedo ladles, shaft kilns, multiple hearth furnaces, and rotary kilns. Some refractory lined vessels have refractory lined conical bottoms. When heated, the conical lining will want to displace upward. Therefore, the top mortar joint of the conical lining is critical. The cylindrical lining will be critical in restraining the upward expansion of the conical lining. At the ends of rotary kilns, restraint must be provided to contain and keep the kiln lining within the kiln shell. 

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