Within-battery-limits

Piping within battery limits which has a concentration of valves, fittings, and flanges. 

Functional unit methods are statistical methods for cost estimation. The production process is divided into functional units. Every chemical or physical treatment of the process flow is expressed as one functional unit. Each unit is weighted by a factor depending on the process intensity, material, and process conditions like pressure and temperature. The within-battery-limits (w.b.l.) costs, the outside-battery-limits (o.b.l.) costs, and the engineering costs are included. The w.b.l. are process equipment costs. The o.b.l. are the other facilities like storage, transportation, utilities and offices. The calculated investments have, within a 95% confidence level, an accuracy of 40%. 

In Fig. 6-4, a typical arrangement for unloading liquid chlorine from tank cars is shown. Liquid flow is through the tank car s liquid eduction valve to a liquid evaporator within battery limits, then direct to process. Whenever liquid chlorine can be trapped between two valves, the line must be protected by an expansion chamber. 

In addition to battery limits investment, off-site investment is required. This includes all structures, equipment, and services that do not enter directly into the chemical process. Within this broad category there are two major classifications, namely, utilities and service facilities. 

Base equipment includes all equipment within the battery limits whose cost is as significant as the cost of a pump. For example, storage tanks, knockout drums, accumulators, heat exchangers, and pumps are classed as main-plant items (MPl). Early in the development of the process-flow diagram, it is advisable to increase the estimated (MPl) cost by 10 to 20 percent to allow for later additions. When the scope of the process has been well defined, (MPl) costs should be increased by 1 to 10 percent. 

Single-factor methods collect the various items of expenditure into one factor, which is usually used to multiply the total cost of delivered equipment X (Ce( )del lo give the fixed-capital cost for plant within the battery limits ... 

The maximum values of electric power and unit output of electrochemical cells vary within wide limits. The total current load admitted by individual electrolyzers for the electrochemical production of various materials in plant or pilot installations (their capacity) is between 10 A and 200 kA, while the current loads that can be sustained by different types of battery (their current ratings) are between 10 A and 20 kA. Corresponding differences exist in the linear dimensions of the electrodes (between 5 mm and 3 m) as well as in the overall mass and size of the reactors. 

In addition to the investment within the battery limits, investment is also required for the structures, equipment and services outside of the battery limits that are required to make the process function. 

The cost of utilities is considered from their sources within the site to the battery limits of the chemical process served. 

Solve the problem given in Example 9-4 using the Miller method. Let us assume that 10 of the pumps and all the storage tanks are not within the battery limits. The total estimated F.O.B. price of the equipment in 1972 is then 1,105,000. The cost of it delivered, assuming a 5% freight charge (sales tax is not included), is... 

Design water rates should be based on the ground areas within each unit s battery limit when separated by at least the distance specified in the spacing table. When the spacing within units is such that the processes are separated by at least 50 ft (15 m), the area demand may be calculated separately by using Figure 7-8, but, at a minimum, should be 3,000 gpm (11,400 1/min). 

Within process unit battery limits of processing facilities, potassium bicarbonate dry chemical extinguishers should be provided along main access ways. On elevated structures, the extinguisher locations should be near stairway landings. 

Catch basins should be provided for each fire zone of the process area to collect the flow from the floor drains and trenches. All catch basins within the process area battery limits should be sealed for vapor control. Catch basin seals should be of types that are easily cleaned out. P-traps should not be used. Catch basins require a periodic check to verify that a liquid seal is in place and clean-out plugs are installed. 

Manholes inside process area battery limits should be vented at least 18 in (46 cm) above the highest pipelines or equipment within a 10-ft (3-m) radius or... 

The required protection may be obtained by active, passive, or a combination of both protection systems. For example, steel support located in a fire exposed area within process unit battery limits may be protected by either a fixed water spray system or the application of fire resistant insulating material to the steelwork or possibly both. Note Passive protection is generally the preferable method for protecting structural steel. 

Any industrial activities present in the area (type, WW flow rate, adopted pretreatments within the factory battery limits, final disposal of the effluent, cotreatment with other kind of WWs, etc.)... 

Classification of Estimates There are two broad classes of estimates grass roots and battery limits. Grass-roots estimates include the entire facility, starting with site preparation, buildings and structures, processing equipment, utilities, services, storage facilities, raihoad yards, docks, and plant roads. A battery-limits estimate is one in which an imaginary boundary is drawn around the proposed facihty to be estimated. It is assumed that all materials, utilities, and services are available in the quality and quantity required to manufacture a product. Only costs within the boundary are estimated. 

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

The capital cost required for the provision of utilities and other plant services will depend on whether a new (green field) site is being developed, or if the plant is to be built on an existing site and will make use of some of the existing facilities. The term battery limits is used to define a contractor s responsibility. The main processing plant, within the battery limits, would normally be built by one contractor. The utilities and other ancillary equipment would often be the responsibility of other contractors and would be said to be outside the battery limits. They are often also referred to as off-sites . 

For all instrument systems within the defined battery limits performing the following operations ... 

The plant battery limits are shown in the general lay-out plans, Fig. 8, Fig. 9 and Fig. 10. Buildings such as workshop, warehouse and administration buildings are included. Product loading facilities for gasoline and LPG are not included within the battery limits. 

Before beginning an economic analysis to define the most convenient trade-oflF between evaporation and electrolysis cost, the upstream plants where sodium sulfate is generated should be inspected carefully to determine whether the dilute solutions are formed as such or are the result of mixing with other process wastewaters. Internal dilution is often a consequence of the old attitude toward by-product salt solutions, which were diluted as much as possible within the battery limits of the plants to reach the limit allowed for discharge. 

The rates of the electrochemical reactions that proceed at the two types of plates depend on current density. Increase of formation current is associated with increase of the heat effects of the reactions and of the Joule heat released. This causes the temperature in the battery to rise. And battery temperature is one of the technological parameters that should be kept within definite limits to ensure high battery performance characteristics. So the basic dependencies that have to be monitored and controlled during the formation process are current, battery voltage and temperamre as a function of formation time. 

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