Cost sheet utilities

This term includes, power, steam, compressed air, cooling and process water, and effluent treatment unless costed separately. The quantities required can be obtained from the energy balances and the flow-sheets. The prices should be taken from Company records, if available. They will depend on the primary energy sources and the plant location. The figures given in Table 6.5 can be used to make preliminary estimates. The current cost of utilities supplied by the utility companies electricity, gas and water, can be obtained from their local area offices. 

Operating Cost and Economic Analysis. This section begins with a presentation of the annual costs of operating the proposed plant, that is, the cost sheet, as discussed in Section 17.2 and shown in Table 17.1. In addition to the total production cost on the cost sheet, it should provide an estimate of the cost per unit weight of the product (e.g., per lb, kg, ton, or tonne). Note that when cash flows are computed for different production rates from year to year, a separate cost sheet is required for each unique production rate. Note also that, in addition to appearing on the cost sheet, the utilities for each equipment unit and their costs should be sununarized in a separate table. 

Base Metal Finishes. The low cost of base metal finishes obviates selective coating. Electro deposition is used for 0.5—5 p.m thick coatings of tin and tin—lead alloy, usually about 50 wt % Sn, 50 wt % Pb, on electronic connector contacts, on contacts at the edges of printed circuit boards, and on terminals. Sheet copper alloys that have been coated with tin—lead alloy are widely used for contacts that are stamped and then formed into the desired shapes, such as pins having a closed end and sockets. Aluminum connectors that have utility—industrial appHcations are more thickly coated, and hot-dipping in molten tin is common. 

Variable costs 1. Raw materials 2. Miscellaneous materials 3. Utilities 4. Shipping and packaging Typical values from flow-sheets 10 per cent of item (5) from flow-sheet usually negligible... 

The geometries for asymmetric mixed-matrix membranes include flat sheets, hollow fibers and thin-fihn composites. The flat sheet asymmetric mixed-matrix membranes are formed into spirally wound modules and the hollow fiber asymmetric mixed-matrix membranes are formed into hollow fiber modules. The thin-film composite mixed-matrix membranes can be fabricated into either spirally wound or hollow fiber modules. The thin-film composite geometry of mixed-matrix membranes enables selection of different membrane materials for the support layer and low-cost production of asymmetric mixed-matrix membranes utilizing a relatively high-cost zeolite/polymer separating layer on the support layer. 

Advantages of plywood are many fold. The chief purpose in overlaying the wood first practiced by the ancients and later by artisans in the 18th and 19th centuries was to produce a surface of beauty over a less aesthetic surface. Today plywood is a mixture of this same objective of aesthetics and the functional period. The inherent property of veneercutting utilizes the valued woods in full-size sheets to its greatest potential, whereas other methods of utilization would be too costly or impossible. 

The submerged MBR system is a small-footprint, single-process unit that can achieve a high-quality standard with low solids production. The membrane systems typically utilize either micro- or ultramembranes configured as hollow fibers, flat sheets, or tubes depending upon the manufacturer. Experience over the past decade has proved MBRs to be reliable and cost-effective for high-quality effluent applications, and relatively easy to maintain and operate. The key parameters for MBR... 

The solution to the problem is obtained by solving mass and energy balances to yield the quantity and state (i.e., composition, temperature, pressure) of all the streams and the utility requirements. Additional parameters for the process equipment, sufficient so that stream specifications are met and the cost of the equipment can be estimated, are calculated. The cost of equipment, raw materials, and utilities is estimated and an economic analysis is carried out. Methods of cost estimation and economic analysis are presented later in this text. This entire procedure may be repeated many times to examine modifications of the process flow sheet or to find optimal values of key process variables. Computer software can greatly simplify these repetitive calculations for the engineer. But even without the need for repetition, the software may simplify the calculations and provide detail and accuracy that would have been impossible otherwise. 

The cost of manufacturing thermoformed, polystyrene foam sheet parts is less dependent on raw material cost than other extrusion processes. This is largely due to the combined effects of additional energy costs required to operate two extruders, heat removal requirements in the secondary extruder, cost of pelletizing (densifying) regrind and the relatively low output of the process for the equipment scale and cost. Typical cost factors for the manufacture of thermoformed polystyrene foam sheet products include raw materials 35%, labor 27%, sales and administration 16%, depreciation 8%, utilities 7% and other 7%. 

Classically, flat-sheet porous PTFE or polypropylene membranes are used as support for the membrane liquid and mounted in holders (cells, contactors) permitting one flow channel on each side of the membrane [1,3,6,8,25]. See Figure 12.1. Such membrane units are typically operated in flow systems and in principle apphcable to aU versions of membrane extraction for analytical sample preparation or sampling. Such a setup can be easily interfaced with different analytical instmments, such as HPLC and various spectrometric instmments, and thereby provides good possibdities for automated operation. Drawbacks of this type of devices are relatively large costs and limited availability, as well as some carryover and memory problems as the membrane units are utilized many times, necessitating cleaning between each extraction. 

It is useful to create a single-page summary of all of the production costs and revenues associated with a project, as this makes it easier to review the project economics and understand the relative contribution of different components to the overall cost of production. The summary sheet usually lists the quantity per year and per unit production of product, the price, the cost per year, and the cost per unit production of product for each of the raw materials, byproducts, consumables, and utilities, as well as fixed costs and capital charges. 

Utilities. The utility requirements for a process are obtained from both a material and energy balance. The unit costs for each utility may be obtained from plant expense sheets, the accounting department, or a utility superintendent. These costs often increase continually, so they should be reviewed frequently. Utilities are usually steam (high-, medium-, and low-pressure) and their associated unit costs, electricity, natural gas, cooling tower water, and treated or city water. Sometimes instrument air, demineralized water, and refrigeration are considered utilities if they come from a central source and are not tied to a given process. 

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