Equipment purchase costs evaporators

The process system consists of two long-tube vertical evaporators, a draft-tube baffled crystallizer, a rotary-drum vacuum filter, and a direct-heat rotary dryer. Also, pumps are needed to move the solution from evaporator 1 to evaporator 2, to recycle the filtrate from the filter to the crystallizer, and to move the magma from the crystallizer to the filter and a heat exchanger is needed to heat the recycle filtrate. However, the purchase costs for the three pumps and the heat exchanger are not considered here because examples for these types of equipment are presented in Section 16.5. For the equipment considered here, assume fabrication from stainless steel, with a material factor of 2 for the ratio of stainless steel cost to carbon steel cost. For the process, using the following size factors and the equations in Table 16.32, the estimated f.o.b. equipment purchase costs at a CE index of 394 are included in the following table. 

However, HPLC is not without its drawbacks 1) equipment cost is very high (thus small processing operations would probably be unable to purchase and maintain such an instrument) 2) only one compound can be measured at a time since different columns and solvents are used for each class of compounds (this also means that time must be spent in changing the system from one analysis to the next) 3) pre-purification is required and for good resolution repeated liquid-liquid and evaporation steps are involved 4) the procedure is slow (only 10-15 samples can be processed per person per day) 5) it is sensitive only to the parts per million (ppm) range (pg/gm). Thus, in summing the current status of limonin and naringin quantification, a quotation is most appropriate. 

The two major costs associated with evaporators, as with any process equipment, are capital investment and operating costs. The best estimate of the installed cost of evaporation systems is, of course, a firm bid from a vendor. The installed cost, however, can be estimated based on the heat transfer surface area, as in Peters and Timmerhaus. Costs taken from published references must be adjusted for changes subsequent to the time of publication. To do this, one may use an index such as the Marshall and Swift allindustry index. The value of this index is published each month in Chemical Engineering, a McGraw-Hill publication. Further information on the use of this and other cost indices as well as their histories are available, for example, in Peters and Timmerhaus and Ulrich.f Variation of purchased evaporator costs with material of construction and pressure can also be found in Ulrich. ... 

---