Control capital cost

Particle Segregation Mechanisms. Segregation is the process by which an assembly of soHd particles separates as it is being handled. This often results in cosdy quaUty control problems due to the waste of raw or finished materials, lost production, increased maintenance, and capital costs required to retrofit existing faciUties. 

Annual iadirect costs are estimated as percentages of the direct labor and fixed capital costs. Typical direct labor percentage ranges are 25—30% for payroll overhead, 15—20% for stores and suppHes, 10—20% for control laboratory, 10—20% for security, 10% for yard, and 10—15% for process improvements. That is, total iadirect costs are usually 80—115% of the direct labor cost (1). 

For control purposes it is advisable to estimate startup cost and time beforehand and then try to stay within the estimates. Tne general parameters which can be used to estimate startup cost Csu, which are usually between 2 and 20 percent of the batteiy-limit fixed-capital cost, are as follows ... 

Project Control Having made a good estimate of the capital cost and the expected construc tion time, it is essential to introduce an effective system for controlling expenditure of time and money during construction. Good capital-cost control can cut down expenditures even when the definitive estimate is not veiy accurate. It is most important for management to receive early warnings if overruns in expenditure or time are likely to occur. 

Economic factors include (a) the capital cost of the control technology (b) the operating and maintenance costs of the technology and (c) the expected lifetime and salvage value of the equipment. 

Pollutants that require an unusually high level of control or that require the fabric filter bags or the unit itself to be constructed of special materials, such as Gore-Tex or stainless steel, will increase the costs of the system. The additional costs for controlling more complex waste streams are not reflected in the estimates given below. For these types of systems, the capital cost could increase by as much as 75 % and the operational and maintenance (O M cost could increase by as much as 20%. 

Applications listed in Table 1 are typical, but not inclusive. This is a workhorse piece of equipment used in a wide variety of versatile applications. Its high capital cost requires careful consideration of design and selection as the means of control. 

The advantages of thermal incineration are that it is simple in concept, has a wide application, and results in almost complete destruction of pollutants with no liquid or solid residue. Thermal incineration provides an opportunity for heat recovery and has low maintenance requirements and low capital cost. Thermal incineration units for small or moderate exhaust streams are generally compact and light. Such units can be installed on a roof when the plant area is limited. = The main disadvantage is the auxiliary fuel cost, which is partly offset with an efficient heat-recovery system. The formation of nitric oxides during the combustion processes must be reduced by control of excess air temperature, fuel supply, and combustion air distribution at the burner inlet, The formation of thermal NO increases dramatically above 980 Table 13.10)... 

The major disadvantage of the gas turbine is its low efficiency when compared with other systems. However, the gas turbine is compact, is subject to short delivery and erection period, has a competitive capital cost, and has virtually no requirement for cooling water. It can be started rapidly on fully automatic control. 

Item 1 is the major factor in choosing continuous systems rather than batch systems for improved SCP production. Economics are improved by lower capital cost for the bioreactor (a conomica major equipment cost, see Section 4.10) and by a higher output rate. Item 3 leads to greater control of product quality. 

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