Revised Cost Estimation

The need for a clamp-ring, internal floating-head, shell and tube-type heat exchanger for use as a steam superheater is determined. The 

The shell is constructed from carbon steel and will be fabricated from standard pipe of nominal size 30, schedule number 80. The 112 tubes required are 1.83 m (6ft) lengths and standard BWG 12. The tubes are made from stainless steel type 250 as recommended in the Australian Design Code AS1548 Design of Boilers and Pressure Vessels. 

Some design problems became apparent when using the Kern method. The method resulted in overestimation of the shell-side heat-transfer coefficient and shell-side pressure drop. If the unit specification has proceeded based only on the Kern results the exchanger would have been unable to achieve the desired level of heat-transfer. The Bell method is recommended to avoid these problems. 

Process Heat Transfer, McGraw-Hill, New York (1950). 

Coulson and J.F. Richardson, Chemical Engineering, Volume 6, Chapter 12, Pergamon Press, UK (1983). 

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F. A. Peters and P. W. Johnson, Revised and Updated Cost Estimates for Producing Alumina from Domestic Raw Materials, Circular 8648, Bureau of Mines Information, Washington, D.C., 1974. 

The cost of each item in a cost estimate should be presented in such a way that the estimate can be modified and updated at any time in the future when revised data become available. 

The team should also measure the success of the pilot project itself— compared with the plan how long did each activity take, or how many new processes were developed, or how many programs and elements needed to be developed or upgraded compared with your plan This will allow you to reconsider the overall project cost estimate and revise it if necessary. 

The capital cost estimation for this unit is revised because of the detailed design information now available. The essential features... 

Even with the best intentions and careful review of the contract, either party may find that part of the way through the conduct of the activities it is necessary to revise the scope and perhaps the timeline and cost estimates. Provisions for how to approach such discussions should be provided in the contract, and these discussions may be best handled by senior management in both companies to preserve the working relationships of the members of any joint working teams. 

Topf revised its cost estimate for the third oven on September 25, 1941,82 and sent the required material to Auschwitz on October 21, a total of 3,548.5 kg.83 Construction of the foundation for the third oven began on November 19,1941, and was completed on December 3 84 work was then discontinued due to a lack of fireproof material. The pertinent invoice issued by Topf is dated December 16, 1941.85 Due to a Waggonsperre (railroad car prohibition86), however, construction of the ovens... 

The revised preliminary execution plan promotes thinking and raises questions that must be answered in order to refine the plan and prepare an accurate appropriation cost estimate. 

The cost estimate presented last year for the integrated reactor process was reviewed and revised. The cost components with significant revisions were costs of reactor, instrumentation, natural gas and capital recovery. In addition, the costs related to contingency and safety were added. To estimate... 

Figures 2 and 3 show the revised capital and product costs for the process with the integrated reactor. Figures 4 and 5 show capital and product costs for the process with the sequential reactors. The range in capital costs for any given point is due to the level of uncertainty in the cost estimate, especially in the costs of membrane reactors.

This analysis of individual costs making up the total cost of demineralization by electrodialysis helps to pinpoint the areas needing the greatest research effort. The costs are based on two published cost estimates, revised on a comparable basis for a 2,000,000-gallon-per-day plant. These studies indicate that development of methods to reduce concentration polarization within the compartments offers the best means of reducing the cost of demineralization by electrodialysis, not only because the limiting current density might be increased, but also because of the reduction in resistance that occurs when concentration polarization is eliminated. 

Revision and modernization of the-text material from previous editions has been incorporated in a different sequence of presentation. It is assumed that the reader has a sufficient background in process calculations and technology, thermodynamics, unit operations and processes, and elementary engineering economics as taught in an undergraduate chemical engineering curriculum. The first six chapters of the present edition can then be used as a text for course work in process development where the ultimate goal is to arrive at a preliminary cost estimate. 

A significant reduction to the estimated deactivation costs is expected to be realized. The effort to revise the cost estimate is ongoing because the deactivation program is refined and optimized based on the outcome of value engineering analyses and other planning activities that are currently being performed (see Table 8-1). 

J. C. Heap, Cost Estimates for Reactor Containment, (Reactor Engineering Division) Tech. Memo No. 13 (Revised), Argonne National Laboratory, October 1957. 

The British electric power industry also appears to have initially overestimated the costs of reducing SO2 emissions. It recently cut its cost estimates in half in the face of mounting pressure from the European Economic Community for a 60% reduction in SO2 emissions in Europe by 1995. Britain s Central Electricity Generating Board had reported in the fall of 1983 that abatement would cost 4,000 million pounds in the spring of 1984 the Board revised its estimate downward to 1,400 million pounds, or 120 million pounds per plant. The price of electricity to consumers would increase by 4% according to current industry estimates. 

Lobato19 studies the direct control of drag prices in Spain based on the difficulty of inspecting costs it is complicated to allocate fixed costs and estimate the size of the market for each product. Revisions of authorized prices to make up for inflation would have been insufficient. The main conclusion is the... 

Estimated costs for the field demonstration of the IGRS have been summarized in Table 1. Initial estimates will be revised as actual cost data becomes available. These estimates are primarily those costs associated with actual waste site remediation and do not include all of the project costs associated with development of the technology. It is assumed that the total remediation effort wUl require 2 years (D14727N, pp. 23, 25). 

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