Oxidation pipes

Table 5-2 shows values of (h + h ) from single horizontal oxidized pipe surfaces. 

Nitrous oxide piping systems for the in-plant transfer and distribution of nitrous oxide must be designed, installed, maintained, and operated in accordance with the Compressed Gas Association pamphlet G-8.1-1964. 

If necessary, first-stage reactor effluent maybe further cooled to 200—250°C by an iaterstage cooler to prevent homogeneous and unselective oxidation of acroleia taking place in the pipes leading to the second-stage reactor (56,59). 

The cooled, dried chlorine gas contains - 2% HCl and up to 10% O2, both of which are removed by Hquefaction. A full scale 600-t/day plant was built by Du Pont ia 1975. This iastaHatioa at Corpus Christi, Texas operates at 1.4 MPa (13.8 atm) and 120—180°C and uses tantalum-plated equipment and pipes. Oxidation of HCl Chloride by JSHtricHcid. The nitrosyl chloride [2696-92-6] route to chlorine is based on the strongly oxidi2iag properties of nitric acid... 

Several studies of spherical and cylindrical detonation in acetylene—oxygen and acetylene—air mixtures have been reported (82,83). The combustion and oxidation of acetylene are reviewed extensively in Reference 84. A study of the characteristics and destmctive effects of detonations in mixtures of acetylene (and other hydrocarbons) with air and oxygen-enriched air in earthen tuimels and large steel pipe is reported in Reference 81. 

Seaweeds. The eadiest successful manufacture of iodine started in 1817 using certain varieties of seaweeds. The seaweed was dried, burned, and the ash lixiviated to obtain iodine and potassium and sodium salts. The first process used was known as the kelp, or native, process. The name kelp, initially apphed to the ash of the seaweed, has been extended to include the seaweed itself. About 20 t of fresh seaweed was used to produce 5 t of air-dried product containing a mean of 0.38 wt % iodine in the form of iodides of alkah metals. The ash obtained after burning the dried seaweed contains about 1.5 wt % iodine. Chemical separation of the iodine was performed by lixiviation of the burned kelp, followed by soHd-Hquid separation and water evaporation. After separating sodium and potassium chloride, and sodium carbonate, the mother Hquor containing iodine as iodide was treated with sulfuric acid and manganese dioxide to oxidize the iodide to free iodine, which was sublimed and condensed in earthenware pipes (57). 

In the fumace/ketde batch process, a charge of drossed blast furnace buUion is treated in a reverberatory furnace or a kettie (see Fig. 12). Oxygen is supphed in the form of compressed air or as lead oxide blown into the bath through submerged pipes. The formation of lead oxide serves by mass action to assure the removal of the impurities to the desired low concentrations. The softening reactions are... 

The continuous softening process used by The Broken Hill Associated Smelters Pty., Ltd. is particularly suitable for lead buUion of fairly uniform impurity content. The copper-drossed blast furnace buUion continuously flows in the feed end of a reverberatory furnace at 420°C, and the softened lead leaves the opposite end at 750°C. Oxidation and agitation is provided by compressed air blown through pipes extending down through the arch of the furnace into the bath. 

The cobalt deposition rate on new, replacement, or decontaminated recirculation piping surface has been reduced by pretreating the piping using an atmosphere of oxygenated wet steam to form an oxide film (25). Studies have been conducted for both PWRs and BWRs to reduce the cobalt content of materials used in the nuclear parts of the plants, particularly in hardened and wear surfaces where cobalt-base alloys ( 50% Co) are used (26). Some low cobalt materials have been developed however, the use of the materials is limited to replacement parts or new plants. 

Metal oxides found in RO feed streams typically originate from corroded pipes found in the RO process. These metal oxides can deposit on the membrane surface and decrease the membrane flux. This type of fouling can be prevented by using the proper materials of constmction in the piping system to prevent corrosion. 

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