Plot plans types

Equipment Selection Criteria and Guidelines A number of factors should be considered in order to determine when to select a blowdown drum, cyclone separator, or quench tank to handle a multiphase stream from a relief device. Among these are the plot plan space available, the operating limitations of each type, and the physicochemical properties of the stream. 

Cyclone separator with separate catch tank This type of blowdown system, shown in Figs. 23-52 and 23-53, is frequently used in chemical plants where plot plan space is limited. The cyclone performs the vapor-liquid separation, while the catch tank accumulates the liquid from the cyclone. This arrangement allows location of the cyclone knockout drum close to the reactor so that the length of the relief device discharge line can be minimized. The cyclone lias internals, vital to its proper operation, which are discussed in the following subsections. 

Field Locations. For each field test location a variety of information is collected and recorded in addition to the samples which are collected. Seven general categories of information can be defined. Three simple ones are 1) test design or plot plan, 2) location and 3) field use history for several years. Field soil characterization 4) includes screen analysis (soil type), pH measurement, and organic matter content. Weather information 5) includes daily temperatures and rainfall and/or irrigations during the test. Application related data 6) consists of dates, application modes, weather conditions at application, calculations and calibrations. Harvest information 7) includes crop name, part, amount, date, and collector. 

Definitive estimates. Definitive cost estimates are the most time-consuming and difficult to prepare, but they are also the most accurate. These estimates require preparation of plot plans, detailed flow sheets, and preliminary construction drawings. Scale models are sometimes used. All material and equipment is listed and priced. The number of labor hours for each construction activity is estimated. Indirect field costs, such as crane rentals, costs of tools, and supervision, are also estimated. This type of estimate usually results in an accuracy of 5%. 

In contrast, fire-tube boilers are much better suited for natural circulation and the steam drum can sit in piggyback-fashion, right on top of the boiler. This makes it possible to provide each boiler with its own separate steam drum, which allows greater flexibility in the plot plan. But it took some time before this boiler type was accepted in ammonia plants as the stress pattern is more complex and less predictable than in water-tube boilers. 

Definitive and/or appropriation type estimates can be developed in four or six hours with the information normally provided in a Phase 1 package, i.e., P ID s, equipment list, plot plans, arrangement drawings, and single line electrical diagram. 

Unit Areas Concept. The basic blocks with which to build an arrangement for plot plans are often used in the unit area concept. This method of planning is particularly well adapted to large plant layouts. Unit areas are often delineated by means of distinct process phs s and operational procedures, by reason of contamination, and by safety requirements. Thus, the delineation of the shape and extent of a unit area and the interrelationships of each area in a master plot plan is one of the first tasks of layout planning. Figure 5-1 is an example of this type of planning. 

Plot plans are often referred to by their process (e.g., an ammonia plant or hydrotreater unit) rather than by the type of configuration of the equipment layout. In terms of equipment arrangement, process unit plot plans can basi Iy be divided into two configurations the grade-mounted horizontal inline arrangement seen in most refinery facilities, and the structure-mounted vertical arrangement found in many chemical plants. 

The advantages of this type of arrangement are the small amount of real estate required for the plant and the ability to house the facility to suit process requirements or climate conditions. The disadvantages are in the operator and maintenance access and in the construction of the plant. Exhibit 3-8 shows a npical structure-mounted vertical plot plan arrangement. 

By plotting the cumulative resource weighting against time, the planned progress of the project can be illustrated, as shown in Figure 12.8. This type of plot Is often referred to as an S -Curve, as projects often need time to gain momentum and slow down towards completion (unlike the example shown). 

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