Mild-steel reactor

Many applications of novolacs are found in the electronics industry. Examples include microchip module packaging, circuit board adhesives, and photoresists for microchip etching. These applications are very sensitive to trace metal contamination. Therefore the applicable novolacs have stringent metal-content specifications, often in the low ppb range. Low level restrictions may also be applied to free phenol, acid, moisture, and other monomers. There is often a strong interaction between the monomers and catalysts chosen and attainment of low metals levels. These requirements, in combination with the high temperature requirements mentioned above, often dictate special materials be used for reactor vessel construction. Whereas many resoles can be processed in mild steel reactors, novolacs require special alloys (e.g. Inconel ), titanium, or glass for contact surfaces. These materials are very expensive and most have associated maintenance problems as well. 

Unfortunately, the water contained nitrates, which caused stress corrosion cracking of the mild steel reactor. The reactor was removed for repair, and the temporary pipe that replaced it later failed and caused the explosion (see Section 2.4). 

Instead of a closed-bomb reactor, an open reactor (shown in Figure 4.17 B) has also been used for this aluminothermic reduction. The mild steel reactor is lined on the inside with calcined magnesia. An arrangement is made to initiate the reaction in the center of the... 

Solution. By Eq. (28), the capitalized cost for the mild-steel reactor is... 

Thus, the useful-life period of the stainless-steel reactor should be 11.3 years for the two types of reactors to have equal capitalized costs. If the stainless-steel reactor would have a useful life of more than 11.3 years, it would be the recommended choice, while the mild-steel reactor would be recommended if the useful life using stainless steel were less than 11.3 years. 

Kraft cooking liquor in digester Mild steel >177 Reactor 3D X 14H 1 Time 30 I96 ll... 

Rubber sheets are the most important materials for the construction and fabrication of much chemical plant equipment such as storage tanks, reactor vessels, pipelines, seals, hoses and rubber lined mild steel equipment of different sizes and shapes, inflatables, etc., and almost all equipment subjected to different corrosive environments. The rubber sheets can be either plain or fabrics coated with rubber. The fabrics used for coating are nylon, rayon, cotton or various other synthetics. Rubberized fabric cords are also used as reinforcing members in various products. 

Steam Superheater This unit superheats saturated steam from 250°C (and 4000kPa) to 380°C. The product steam is of medium pressure and suitable quality for in-house application and also for export. The superheater cools the reaction gases from the reactor exit temperature of 645°C to 595°C. Design pressure on the shell side is approximately 5000 kPa. The steam superheater is constructed from mild steel. 

These two units are costed as pressure vessels using Ref. CE1 0. The reactor operates at 10 bar and approximately 940°C. It is constructed of mild steel and is refractory lined. The final Australian cost was estimated to be As46 000. Including the cost of the exchanger... 

Some examples of the phenomenon of breakaway corrosion are encountered in nuclear reactors used for power generation. In some reactors carbon dioxide is used as a coolant. Mild steel is chosen for use in gas-cooled reactors at 400°C, steel containing chrominum... 

The capitalized-cost profitability concept is useful for comparing alternatives which exist as possible investment choices within a single overall project. For example, if a decision based on profitability analysis were to be made as to whether stainless steel or mild steel should be used in a chemical reactor as one part of a chemical plant, capitalized-cost comparison would be a useful and appropriate approach. This particular case is illustrated in Example 9 of Chap. 7. 

You are the engineer in charge of an adiabatic CSTR producing propylene glycol by this method. Unfortunately, the reactor is beginning to leak, and you must replace it, (You told your boss several times that sulfuric acid was corrosive and that mild steel was a poor material for construction.) There is a nice overflow CSTR of 300-gal capacity standing idle it is glass-lined and you would like to use it. 

The estimated capital cost is based on the apparatus in Figure 1 using stainless steel for stills 1, 2, 4, 6, and 7 copper for stills 8 and 9, and mild steel for stills 3 and 5. The reactor is constructed from a mild steel pressure vessel with titanium lining. 

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