Process flow diagram stream information

The waste-disposal flow diagram illustrates the waste streams for which there is no further economic use in the plant (see Section 1.3) and indicate their flow numbers from the process flow diagram. Precise information should be given on the toxicity, degradability, water danger, flash point, ignition temperature, MAK, odor threshold, etc. of the individual components, their mass flows, and the state of aggregation of the flow (viscosity, sediment content, etc.). This information makes it possible to specify the type of waste disposal required with consideration of site-specific and economic factors, for example ... 

Process Flow Diagram (PFD) A diagram that shows the material flow from one piece of equipment to the other in a process. It usually provides information about the pressure, temperature, composition, and flow rate of the various streams, heat duties of exchangers, and other such information pertaining to understanding and conceptualizing the process. 

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 process flow diagram is shown in Figure 4.11. This diagram is simplified and drawn as an information flow diagram in Figure 4.12. Only those process units in which there is a difference in composition between the inlet and outlet streams are shown. The... 

Process Flow Diagram and Material Balances. This is the detailed process flow diagram discussed in Section 3.5 and shown for a vinyl chloride process in Figure 3.19. All of the streams are numbered clearly and all of the process units are labeled. At some point on the arc for each stream, the temperature and pressure should appear, or the information should be tabulated (e.g., see Table 3.5). Note that, as mentioned in Section 3.5, many software packages are available to simplify the preparation of flow diagrams, most notably those associated with the process simulators. 

From the FED in Figure 1.3. the identification of the process streams is clear. For small diagrams containing only a few operations, the characteristics of the streams such as tenperatures, pressures, compositions, and flowrates can be shown direedy on the figure, adjacent to the stream. This is not practical for a more complex diagram In this case, only the stream number is provided on the diagram This indexes the stream to information on a flow summary or stream table, which is often provided below the process flow diagram In this text the flow summary table is provided as a separate attachment to the FED. 

I n Chapter 1, the information provided on a process flow diagram, including a stream table and an equipment summary table, was presented. In the next four chapters, this information will be used as a basis for estimating... 

ASME (American Society of Mechanical Engineers), 12 for equipment, 12, 15 information flags, 23-25 for process streams, 16 for utility streams, 16 utility costs, estimating, 247-249 PFD (process flow diagram), process topology conventions for, 14 equipment IDs, reusing, 12, 14 names and numbers, 15... 

In an information flow diagram, such as that shown in Figure 4.5b, each block represents a calculation module that is, the set of equations that relate the outlet stream component flows to the inlet flows. The basic function of most chemical processing units (unit operations) is to divide the inlet flow of a component between two or more outlet... 

The outlet streams from a unit can feed forward to other units, or backward (recycle). An information flow diagram for a process consisting of three units, with two recycle streams is shown in Figure 4.7. The nomenclature defined in Figure 4.6 is used to show the stream flows. 

Using the data given below, draw an information flow diagram of the process and calculate the process stream flow-rates and compositions for the production of 600 t/d ammonia. Use either the Nagiev split fraction method, with any suitable spreadsheet or manual calculations. 

Firstly, we already have a complete flow-diagram (step 11 with all variables and available information. Secondly, with the analysis of degrees of freedom (step III) we have determined hciw many independent materials balance equations (ATMS) there are in the process. Thirdly, given that we already know what is the number of independent materials balance in the process, then we need to determine whidi of the equations will be used. For example in each unit we can choose whether or not to use the total mass balance. In addition, we need to decide whether or not we will use the global mass balance. Given that normally we have information on the input and output streams and its composition appears reasonable, first, to explore the possibility to use the global mass balance. Therefore we need to write all the selected equations and if Df > 0 then specify some variables to get Df=0 to set and solve the problem. 

It is important to remember that flow diagrams represent the most meaningful and useful documents to describe and understand a process. Although PFDs contain a lot of process information, it is sometimes necessary to apply additional knowledge about a unit operation to determine which chemicals are contained in a recycle stream This idea is demonstrated in Example... 

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