Shell-and-Tube Exchanger Costs

Impervious graphite heat exchangers machined from solid blocks are also available (15,16). The solid block constmction is less susceptible to damage by mechanical shock, such as steam and water hammer, than are shell and tube exchangers. Block exchangers are limited in size and cost from 50—100% more than shell and tube units on an equivalent area basis. 

Cost data for shell-and-tube exchangers from 15 sources were correlated and found to be consistent wrien scaled by the Marshall and Swift index [Woods et al., Can. J. Chem. Eng., 54, 469-489 (December 1976)]. 

Shell and Tube Exchanger Selection Guide (Cost Increases from Left to Right)... 

Plate heat exchangers are used extensively in the food and beverage industries, as they can be readily taken apart for cleaning and inspection. Their use in the chemical industry will depend on the relative cost for the particular application compared with a conventional shell and tube exchanger see Parker (1964) and Trom (1990). 

Their major disadvantages are that they require more space, they have a higher initial capital cost, and the coolest temperature that can be attained is 20 to 30°F (10 to 15°C) above the ambient air temperature.1 7 For the same amount of heat transfer, an installed carbon-steel shell-and-tube exchanger will cost about one-third as much as an air cooler. This difference diminishes as more expensive materials are used.18 A modification of the air cooler, called the wet-surface air cooler, overcomes some of the above-mentioned disadvantages. It can reduce the temperature that can be attained to nearly the ambient temperature, and there are some claims... 

Estimate the cost of an all-carbon-steel exchanger in late 2004. Assume a counterflow shell-and-tube exchanger. 

Figure 8.3 s cost curve is based on floating-head shell/tube exchanger construction with carbon steel shell and tubes. The cost figures may reasonably be extrapolated up to 10,000 ft2 of bare outside tube surface area. The subsequent tables, Tables 8.8 to 8.12, include factors for design type, materials of construction, and design pressures up to 1000 psi. Cost factors for foundations, field materials, field labor, and indirect cost may be obtained from these tables. Add each applicable factor, then multiply by Fig. 8.3 base cost. You may interpolate between values shown. 

Figure 8.3 Shell and tube exchanger base cost.

Except for shell and tube exchangers, purchased costs were estimated by means of charts from the Chauvel Method (Chauvel, 2000), then multiplied by correcting factors (materials for example). Other charts have then been used for purchased costs, the second step requiring correcting factors being the same as previously. These different methods show finally various results with a decrease of about 24% of the total capital investment (Peters, 2003 Ulrich, 2004). 

A chart to estimate the costs of ejectors for thermocompression has been developed.Approximate costs of compressors for mechanical vapor recompression also can be found. In addition, these publications contain details of cost estimation for heat exchangers. For more detailed estimation of cost of shell-and-tube exchangers, see Purohit. " Plate-and-frame and spiral-plate heat exchanger costs can be estimated using Kumana. " ... 

---