Equipment, costs glass-lined

The reactor contribution depends on the reactor size and material of construction. Glass-lined reactors are about 40-50 % more costly than the stainless steel reactors. The total investment costs also depend upon the equipment size, as illustrated by Fig. 7.3-1. 

The purchased cost of a 50-gal glass-lined, jacketed reactor (without drive) was 8350 in 1981. Estimate the purchased cost of a similar 300-gal, glass-lined, jacketed reactor (without drive) in 1986. Use the annual average Marshall and Swift equipment-cost index (all industry) to update the purchase cost of the reactor. 

The corrosion resistance of tantalum is similar to that of glass, and it has been called a metallic glass. It is expensive, about five times the cost of stainless steel, and is used for special applications, where glass or a glass lining would not be suitable. Tantalum plugs are used to repair glass-lined equipment. 

From the above discussion, it is clear that a given rate of production can be achieved by different combinations of reactor size and power consumption. The selection of the optimum reactor size is based on the annualized cost of the reactor. The annualized cost consists of the cost of capital (depreciation and interest on fixed cost) and the operating cost. The fixed cost consists mainly of equipment cost (that is, the material cost plus fabrication cost), and the operating cost consists mainly of electricity (power) cost. For the purpose of this illustration, five different materials of construction were selected having costs 0.3,1.0, 3.0,10.0, and 30.0 /kg. This range of costs covers practically all of the materials commonly used in industry, such as mild steel, stainless steel, glass-lined vessels, Hastelloy, titanium-lined vessels, and so forth. Two levels of (depreciation + interest) were examined 20% and 50% per annum. Three costs of electricity were used 0.035, 0.10, and... 

Advantages of the technique are its relatively low cost combined with quickness and ease of operation. One can work with dilute solutions (indeed they are usually a prerequisite) and water is a good solvent as it does not absorb in the UVMsible range. Quartz cells are required for observation of absorptions in the UV range, otherwise glass or plastic (for aqueous solutions) can be used for visible frequencies. Flow cells are available for coupling to separation equipment and absorption can either be monitored at a fixed wavelength for detection of a specific compound or class of compounds, or, if a diode array is available, a complete spectrum can be recorded for each fraction on-line. 

Fabrication begins with a pattern from which a mold is made. The mold may be of any low-cost material, including wood, hard plaster or hydrostone, concrete, a metal such as aluminum or steel, and glass fiber reinforced polyester or epoxy. If only a few parts are to be made, a single mold will suffice otherwise multiple molds may be required. If the volume is large enough and speed is important, heating elements such as lines for steam or other fluids, or electrical heat units, may be incorporated. Automated equipment also may be installed (Fig. 7-6). The mold may be male... 

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