Process flow diagram utilities

The use of process flow diagrams and material balances are worthwhile methods to quantify losses or emissions and provide essential data to estimate the size and cost of additional equipment, other data to evaluate economic performance, and a basefine for tracking the progress of minimization efforts (Ref. 3). Material balances should be apphed to individual waste streams or processes and then utilized to construct an overall balance for the facility. Details on these calculations are available in the literature (Ref. 8). In addition, an introduction to this subject is provided in the next section. 

Once the candidate corrective measure alternatives have been identified, a more detailed evaluation of each alternative needs to be undertaken. From an engineering perspective, the first step in the evaluation process would include the development of a conceptual design for each alternative. The conceptual design would consist of a process description, a process flow diagram and a layout drawing. Preliminary sizing of equipment and utility and land requirements would be developed. In addition, chemical requirements and residuals produced can be estimated. From the conceptual design, permitability and residuals disposal issues can be identified and addressed. 

Process flow diagrams are more complex and show all main flow streams including valves to enhance the understanding of the process as well as pressures and temperatures on all feed and product lines within all major vessels and in and out of headers and heat exchangers, and points of pressure and temperature control. Also, information on construction materials, pump capacities and pressure heads, compressor horsepower, and vessel design pressures and temperatures are shown when necessary for clarity. In addition, process flow diagrams usually show major components of control loops along with key utilities. 

The system has been applied to the agricultural chemical production complex in the lower Mississippi River corridor, and the process flow diagram of plants in this complex is shown in Fig. 10 and is called the base case of existing plants. There are 11 production units plus associated utilities for power, steam and cooling water, and facilities for waste treatment. A production unit contains more than one plant for example, the sulfuric acid production unit contains five... 

System is shown in Fig. 15. A flowsheeting program, HYSIS or other comparable one, is used to develop the process flow diagram. The flowsheeting program determines the operating conditions and the utilities required—steam and cooling water. Then, a value-added economic analysis is performed to estimate the profitability of the plant. If the profitability is acceptable. 

The project engineering department furnishes the piping analyst special requirements for all utility and auxiliary systems which are not shown on the process flow diagram. 

Block flow diagrams are frequently used to represent chemical processes. These diagrams indicate by blocks the key processing steps of chemical reaction and separation. Considerably more detail is shown in process flow diagrams, which also include the auxiliary operations and utilize symbols that depict the type of equipment employed. 

Make available process flow diagrams, process and instrumentation diagrams, utilities and instru-... 

Layout drawings, process flow diagrams (PFDs), utilities flow diagrams (UFDs), P IDs, process and safety diagrams (PSDs), and general arrangements (GA)... 

Note that the unit icons and streams have been repositioned using drag and drop facilities. It is also possible to view a list of the process streams utilized by Aspen IPE that is, a list of all streams and their physical properties in the Process Flow Diagram. Using the View pulldown menu, click on Streams List to produce ... 

Data collection, organization, and analysis are equally important parts of troubleshooting process problems. Process flow diagrams (PFDs) are used to quickly identify the primary flow path and the control instrumentation being used in the process. Checksheets are used to collect data that can be graphically organized or charted to show trends and reveal process variation or changes. Data analysis utilizes a variety of quality techniques to pinpoint process problems and potential issues. 

Fig. 14. The process flow diagram of a utility air drying process (Shaeiwitz et al., 1977).

Figure E6.2 gives the process flow diagrams for the three alternatives and identifies stream numbers and utilities.

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