Acid Resistant Lining

The catalyst solution is highly corrosive and titanium or titanium alloys must be used for equipment in contact with the catalyst. Glass and acid resistant lining are used for equipment which is not exposed to thermal or mechanical shock and rubber or plastic linings are used in low temperature service (< 180 F). 

For illustrative purposes only, instructions for installing an acid-resistant lining with PERMANITE resin from Maurice A. Knight Company will be presented (9). Other companies mentioned previously have comparabTe products. The steps involved are as follows ... 

Acid resistant lining is provided at the bottom plate with a suitable drain for the... 

It is very important to take proper care during erection of process units, plant machinery, site fabrication of large-diameter storage tanks, absorption towers with internal acid-resistant linings and connections of pipelines installation and calibration of instrumentation (e.g. calibrations of level indicators, thermocouples, flowmeters, reaction vessels), curing of the internal lining (of bricks or other material) while setting up a new process plant. 

Refractory-/acid-resistant lining in gas inlet and oudet boxes shall be carried out by vendor to suit drain nozzles on the gas outlet boxes for draining out any (acidic) condensate. 

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. 

Sight glass and light glass nozzles for internal observation (optional) Refractory or acid resistant lining required External insulation and cladding required (optional)... 

In case of acid resistant lining, the curing shonld be done by the same (but diluted) acid to which the lining should be exposed during operation. 

Vinyl plastisol linings are popular for use as an acid resisting lining. Refer to Table 3.5 for the compatibility of the plastisols with selected corrodents. 

Anhydrous phosgene in the liquid state is compatible with a variety of common metals, including aluminum (of 99.5 percent purity), copper, pure iron or cast iron, steel (including cast steel and chrome-nickel steels), lead (up to 250°F or 12 PC), nickel, and silver it is also compatible with platinum and platinum alloys in instruments. Nonmetallic materials with which liquid anhydrous phosgene is also compatible include acid resistant linings (ceramic plates and carbon blocks), enamel on cast iron or glass-lined steel, Pyrex or Kimax, porcelain, quartzware, granite or basalt natural stone, stoneware, and Teflon. 

Liquid sulfur dioxide discolors iron, copper, and brass at ca 300 ppm moisture and produces light scale at ca 0.1 wt % moisture and serious corrosion at ca 0.2 wt % or higher moisture content. Copper and brass can be used to handle wet sulfur dioxide where some corrosion can be tolerated, or where the moisture level is low. Wooden tanks are widely used for sulfurous acid preparation, handling, and storage. Sulfite pulp digestors are made of steel lined with acid-resistant brick. 

Lining vessels and equipment using this type of construction consists of a membrane, acid-resistant bricks or tiles, and chemical-resistant mortar for joining the bricks (tiles) together. 

In such an environment an inner lining of acid-resistant brick is often used. Thermal cycling may also disrupt the film. Acid of more than 85 Vo concentration tends to dissolve the lead sulphate film, although lead has been used in cold quiescent conditions with concentrations of over 90 Vo. 

Brick Construction Brick-lined construction can be used for many severely corrosive conditions under which high alloys would fail. Brick linings can be installed over metal, concrete, and fiberglass structures. Acid-resistant bricks are made from carbon, red shale, or acid-resistant refractory materials. Red-shale brick is not used above 175°C (350°F) because of spalling. Acid-resistant refractories can be used up to 870°C (1600°F). See Table 25-10. 

Other types of refractory that find use are forsterite, zirconia, and zircon. Acid-resisting bricks consisting of a dense body like stoneware are used for lining tanks and conduits in the chemical industry. Carbon blocks are used as linings for the crucibles of blast furnaces, very extensively in a number of countries and to a limited extent in the United States. Fusion-cast bricks of mullite or alumina are largely used to line glass tanks. 

High-quality bricks and tiles are used for lining vessels, ditches and to cover floors. The linings are usually backed with a corrosion-resistant membrane of rubber or plastic, placed behind the titles, and special acid-resistant cements are used for the joints. Brick and tile linings are covered in a book by Falcke and Lorentz (1985). 

Acid refractory furnace linings, 12 300 Acid resistant nanofiltration membranes, 21 635t... 

With reaction conditions of 200-225°F, 150—225 psi, and a palladium chloride-cupric chloride catalyst, MEK yields are 80-90%. The operating costs of the Wacker process for MEK (and acetone and several other petrochemicals as well) are relatively low. But the plant Is made of more expensive materials. Because of the corrosive nature of the catalyst solution, critical vessels, and the piping are titanium-based.(chats expensive ), and the reactor is rubber-lined, acid-resistant brick. ... 

At the Maizuru plant, in Japan [49] PETN was manufactured in World War II in a plant comprising a nitrator lined with acid-resistant steel and provided with a stirrer (140 r.p.m.), a tank made from acid-resistant steel, a centrifuge, a steel crystallizer and unit for recovering acetone. 

In Germany during World War II, cylindrical boilers, provided with mixers, of 10-14 m3 capacity, were used. The vessels were made of sheet-iron or of concrete lined internally with an acid-resistant material, for instance ceramic plates joined by means of a phenol-formaldehyde resin, asplit . 

In spite of the unsaturation of rubber it is said to be resistant to chemical attack since a few chemical derivatives like chlorinated rubbers, cyclised rubbers and chlorides are formed as protective layers retarding further attack by the chemicals. Properly compounded vulcanizates satisfactorily resist the action of most inorganic acids other than oxidizing acids such as nitric, hydrochloric and sulphuric acids. Rubber linings which are to resist swelling to a lower degree should be "tightly" vulcanized. 

Under cure - A low state of cross linking. Often an under cured lining will be low in durometer hardness and fluid and acid resistance will be poor. 

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