Erosion resistivity, refractories

Distributors Carbon steel, top distributor externally lined with 1 in. ( 2 cm) thick erosion-resistant refractory... 

Carbon steel, cold wall with 5 in. (12 cm) thick heavy w eight, erosion-resistant refractory lining... 

Internally lined with 1 inch (2.5 cm) thick, erosion-resistant refractory attached by 304 stainless steel hexmetal anchors with every hex on every other row welded independently. The refractory should be cut out flush with the top of hex. The hexmetal should be discernible after the refractory installation. 

The cyclones in both unit types are lined with erosion resistant refractory. The cydones in the reactors are usually made of carbon steel the cyclones in the regenerators are made of either 2%Cr-l Mo or type 304 (UNS S30400) or 321 (UNS S32100) stainless steel (SS). Oxidation resistance and creep strength, rather than sulfur attack, govern the selection of the cyclone material. 

The metallurgy of the cyclone equipment has in recent years focused primarily on type 304 H stainless steel. The 304 H material is durable and easy to fabricate and repair, withstands the high regenerator temperatures, and is oxidation- and corrosion-resistant. Essentially all internal surfaces of the cyclone that are subject to erosion are protected with a 2 cm layer of erosion-resistant lining. When installed and cured, most refractory linings are highly resistant to erosion. 

Material Shell carbon steel with 4-5 in. (10-12 cm) thick heavy weight, single-layer, cast-vibrated refractory with needles. Internals 304H stainless steel for temperature >1.200°F (650°C) and Grade H, % chrome for < ,200°F. Internal components exposed to catalyst should be refractory-lined for erosion resistance. Sliding surfaces should be hard-faced, minimum thickness in. (3 mm). 

Primary diplegs internally lined with I inch (2.5 cm) thick, erosion-resistant lining. Secondary diplegs lined internally with I inch refractory on the top 5 feet (1.5 m) from the dust-bowl. Externally, diplegs should be lined where the spent catalyst returns and other known turbulent or wear areas. 

Nonmetallic castable refractories, reinforced with hexagonal steel mesh, are particularly good, since they resist both corrosion and erosion. Conventional refractories are susceptible to deterioration by water sprays, but this difficulty can be overcome by shielding from water impingement or by use of special cements. For best results, the refractory is installed flush with the surface of the steel mesh and is commonly applied with a pneumatic gun to ensure completeness of fill and maximum... 

Erosion/Attrition/Thermal Shock. The high velocities of balls in lift pipes and the turbulent nature of the fluidized beds lead to the possibility of erosion of the equipment and attrition or fracturing of the balls. Erosion can be reduced by using abrasion resistant refractory linings in pipes. Attrition and fracturing of balls can be reduced by proper design to reduce the effect of impaction at elbows and on deflection plates. 

Ram HS. [Premier Refractories] Chemicaliy bended high alumina erosion-resistant idasdc. 

The refractory and acid-resistant lining of vessels shall be inert towards the materials being handled. Surfaces in contact with the reactants shall be corrosion-and erosion-resistant. They can be applied with a layer of screened cpharmaceutical industries or if it forms part ement paste and made smooth. 

Resistance Erosion occurs when refractory comes in contact with metal and gas carrying dust and slag particles. Abrasion resistance of refractory is increased by using denser (low porosity), fine grained and wear resistant refractory materials. 

All refractory nitrides can be produced as coatings by CVD and, for most of them, CVD remains a major production process. CVD titanium nitride (TiN) is the most important nitride coating from an application standpoint. It is used extensively mainly for wear- and erosion-resistant applications and as a difrusion barrier and antireflection coating in semiconductor devices.l l... 

The requirements for refractories for the vanes of the degassing units do not differ from the requirements for the melting and holding furnaces (Table 3.6). They are high thermal shock resistance, low wetting by Al, and high erosion resistance. 

The refractory lining of the ladles should be resistant to thermal shock, and the bottom of the ladle should be erosion-resistant. In the tapped aluminium in the ladles, there is some electrolyte, which also attacks the refractory lining of the ladles. Usually, the refractory lining is made from the same materials that are used in the cast house (Table 3.7). 

Corrosion/erosion resistance is one of the most important characteristics of refractories, which are exposed to molten metal and slag. Hence, the design of the tests closely simulating the conditions that the refractories experience during use is of great importance. 

Bricks in the 90% and 99% alumina classes are among the highest strength and erosion resistant of refractory bricks. They are made from synthetic (Bayer process) alumina aggregates, and some types may contain fused alumina for special erosion resistance. It is not surprising that there are several distinct types of brick... 

The walls of the vessels and the flue gas lines are often lined with medium-strength, medium-density refractories since there are few erosion problems and an acceptable shell temperature is the primary concern. Stainless steel fiber additions to the castable are strongly recommended since they have been shown to reduce maintenance costs. The elbows of the overhead flue gas lines may require better erosion-resistant materials because the flue gas can contain some catalyst dust that escapes from the cyclones. The cyclones are connected to a plenum chamber that is welded to the vessel head. The chamber collects the flue gases from the cyclones and transfers them to the overhead line. The plenum skirt has the same temperature on both sides and expands and contracts as the vessel temperature rises and falls. Castable refractory has been used to... 

Slide valves are used to control flow in flue gas lines. The working faces are usually lined with an erosion-resistant plastic or castable refractory held in stainless steel grid or on independent anchors. 

A third group includes silver—nickel, silver—cadmium oxide, and silver—graphite combinations. These materials are characterized by low contact resistance, some resistance to arc erosion, and excellent non sticking characteristics. They can be considered intermediate in overall properties between silver alloys and silver or copper—refractory compositions. Silver—cadmium oxide compositions, the most popular of this class, have wide appHcation in aircraft relays, motor controllers, and line starters and controls. 

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