9780791094075 0791094073 Drug Crime, Michael Benson, John L. French 4988112417588 Tete a Tete, Montoliu Tete 9780311420940 031142094X Diccionario de Hebreo Biblico. A Bayesian Network to Improve Early Detection of Breast Cancer . A New DNA Word Design Strategy. Piping and Instrumentation Diagram (P&ID) The piping and instrumentation diagram (P&ID), also known as mechanical flow diagram (MFD), provides information needed. This chapter covers different types of chemical process diagrams, how these diagrams represent different scales of process views, one consistent method for drawing.
Diagrams for Understanding Chemical Processes . Block Flow Diagram (BFD)This chapter covers different types of chemical process diagrams, how these diagrams represent different scales of process views, one consistent method for drawing process flow diagrams, the information to be included in a process flow diagram, and the purpose of operator training simulators and recent advances in 3- D representation of different chemical processes. This chapter is from the book . In general, chemical processes are complex, and chemical engineers in industry encounter a variety of chemical process flow diagrams. These processes often involve substances of high chemical reactivity, high toxicity, and high corrosivity operating at high pressures and temperatures.
These characteristics can lead to a variety of potentially serious consequences, including explosions, environmental damage, and threats to people’s health. It is essential that errors or omissions resulting from missed communication between persons and/or groups involved in the design and operation do not occur when dealing with chemical processes. Visual information is the clearest way to present material and is least likely to be misinterpreted. For these reasons, it is essential that chemical engineers be able to formulate appropriate process diagrams and be skilled in analyzing and interpreting diagrams prepared by others.
This chapter presents and discusses the more common flow diagrams encountered in the chemical process industry. These diagrams evolve from the time a process is conceived in the laboratory through the design, construction, and the many years of plant operation.
The most important of these diagrams are described and discussed in this chapter. The following narrative is taken from Kauffman . It shows how teams of engineers work together to provide a plant design and introduces the types of diagrams that will be explored in this chapter. The research and development group at ABC Chemicals Company worked out a way to produce alpha- beta souptol (ABS).
Process engineers assigned to work with the development group have pieced together a continuous process for making ABS in commercial quantities and have tested key parts of it. This work involved hundreds of block flow diagrams, some more complex than others. Based on information derived from these block flow diagrams, a decision was made to proceed with this process. A process engineering team from ABC’s central office carries out the detailed process calculations, material and energy balances, equipment sizing, etc. Working with their drafting department, they produced a series of PFDs (Process Flow Diagrams) for the process. As problems arise and are solved, the team may revise and redraw the PFDs.
Often the work requires several rounds of drawing, checking, and revising. Specialists in distillation, process control, kinetics, and heat transfer are brought in to help the process team in key areas. Some are company employees and others are consultants. Since ABC is only a moderate- sized company, it does not have sufficient staff to prepare the 1. P& IDs (Piping and Instrumentation Diagrams) needed for the new ABS plant. ABC hires a well- known engineering and construction firm (E& C Company), DEFCo, to do this work for them.
The company assigns two of the ABC process teams to work at DEFCo to coordinate the job. DEFCo’s process engineers, specialists, and drafting department prepare the P& IDs. They do much of the detailed engineering (pipe sizes, valve specifications, etc.) as well as the actual drawing. The job may take two to six months. Every drawing is reviewed by DEFCo’s project team and by ABC’s team. If there are disagreements, the engineers and specialists from the companies must resolve them. Finally, all the PFDs and the P& IDs are completed and approved.
ABC can now go ahead with the construction. They may extend their contract with DEFCo to include this phase, or they may go out for construction bids from a number of sources. This narrative describes a typical sequence of events taking a project from its initial stages through plant construction. If DEFCo had carried out the construction, ABC could go ahead and take over the plant or DEFCo could be contracted to carry out the start- up and to commission the plant.
Once satisfactory performance specifications have been met, ABC would take over the operation of the plant and commercial production would begin. From conception of the process to the time the plant starts up, two or more years will have elapsed and millions of dollars will have been spent with no revenue from the plant. The plant must operate successfully for many years to produce sufficient income to pay for all plant operations and to repay the costs associated with designing and building the plant.
During this operating period, many unforeseen changes are likely to take place. The quality of the raw materials used by the plant may change, product specifications may be raised, production rates may need to be increased, the equipment performance will decrease because of wear, the development of new and better catalysts will occur, the costs of utilities will change, new environmental regulations may be introduced, or improved equipment may appear on the market. As a result of these unplanned changes, plant operations must be modified. Although the operating information on the original process diagrams remains informative, the actual performance taken from the operating plant will be different. The current operating conditions will appear on updated versions of the various process diagrams, which will act as a primary basis for understanding the changes taking place in the plant. These process diagrams are essential to an engineer who has been asked to diagnose operating problems, solve problems in operations, debottleneck systems for increased capacity, and predict the effects of making changes in operating conditions.
All these activities are essential in order to maintain profitable plant operation. In this chapter, the focus is on three diagrams that are important to chemical engineers: block flow, process flow, and piping and instrumentation diagrams. Of these three diagrams, the most useful to chemical engineers is the PFD. The understanding of the PFD represents a central goal of this textbook.
Block flow diagrams were introduced early in the chemical engineering curriculum. In the first course in material and energy balances, often an initial step was to convert a word problem into a simple block diagram. This diagram consisted of a series of blocks representing different equipment or unit operations that were connected by input and output streams. Important information such as operating temperatures, pressures, conversions, and yield was included on the diagram along with flowrates and some chemical compositions. However, the diagram did not include any details of equipment within any of the blocks.
The block flow diagram can take one of two forms. First, a block flow diagram may be drawn for a single process. Alternatively, a block flow diagram may be drawn for a complete chemical complex involving many different chemical processes. These two types of diagrams are differentiated by calling the first a block flow process diagram and the second a block flow plant diagram. Block Flow Process Diagram. An example of a block flow process diagram is shown in Figure 1. Figure 1. 1. Block Flow Process Diagram for the Production of Benzene.
Toluene and hydrogen are converted in a reactor to produce benzene and methane. The reaction does not go to completion, and excess toluene is required. The noncondensable gases are separated and discharged. The benzene product and the unreacted toluene are then separated by distillation.
The toluene is then recycled back to the reactor and the benzene removed in the product stream. This block flow diagram gives a clear overview of the production of benzene, unobstructed by the many details related to the process. Baud Port Checker Rar Download on this page.