Equipment Design — HELP

Not all the students in a chemical engineering course have mastered all the basic principles that have been taught, many students feel uncertain about their ability to transform basic theory into an engineering design 

Whatever you have to design there is always some information available. In the absence of hard data, agree with the supervisor the necessary assumptions/estimates that will enable the design to proceed. Write down all the available information which might be applicable to the design of this item of equipment. Itemise the information that is required, but not available, for the design. 

DO NOT flounder at this stage, decide to begin (and begin to decide ) and make the list of available (and required) information. 

DO NOT expect the data to be absolute, this is not a textbook problem, some data will be contradictory and some decisions will be based upon estimates. Some students become paralysed, unwilling to proceed, because the problem is not clearly defined and all necessary information is not available. Make a start, check the validity of any estimates as the design proceeds. 

Formulate a statement of the design criteria for the unit. What is the general design criteria What is the design (or the unit) intended to achieve For example, a reactor is usually required to achieve a particular conversion of reactants to products, a distillation column must provide a particular separation, an absorption column provides removal of a specific level of impurity, etc. 

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Many of the better known shortcut equipment design methods have been derived by informed assumptions and mathematical analysis. Testing in the laboratory or field was classically used to validate these methods but computers now help by providing easy access to rigorous design calculations. 

If it is assumed that explosible dust will be present above the MEC, and equipment design data are not required, explosibility testing forP g, and Kg usually has no direct application. However, minimum ignition energy (MIE) testing should be considered to help determine the likelihood of ignition. Since MIE is extremely sensitive to particle size it is especially important to test a sample that is sufficiently fine to represent the worst credible case. 

The hazard tree also helps identify protection devices to include in equipment design that may minimize the possibility that a source will develop into a condition. Examples would be flame arrestors and stack arrestors on fire tubes to prevent flash back and exhaust sparks, gas detectors to sense the presence of a fuel in a confined space, and fire... 

Preserve a record of design conditions and materials of construction for existing equipment, which helps ensure that operations and maintenance remain faithful to the original intent... 

The potential influencing factors are selected based on whatever is relevant to the task or process, and will likely include factors such as working conditions, administrative controls, communication, supervision, training, and equipment design, operation, and maintenance. The inclusion of questions such as What Where When and Who may also be help-... 

Familiarity with individual experiments and equipment will help you evaluate if anything is missing from the design. For data requiring a difference between two values, the experiment must determine both values. For data utilizing the ideal gas law, the experiment must determine three values of P, V, n, or Tin order to determine the fourth or one value and a ratio of the other two in order to determine the fourth. 

Based upon the reports and the accompanying photos, there were apparent troubles with crowd control and other emergency response considerations. It also appears that there were equipment design shortcomings. Still, a top-notch viable mechanical integrity program would have eliminated or helped minimize the extent of the incident. 

Alternative PPV equipment, designed and used for short-term PPV in non-lCU locations, but suitable for definitive mechanical ventilation during mass casualty events, should be considered. This equipment is available, less expensive, and more easily stockpiled than full feature mechanical ventilators. Alternative PPV equipment must be easy for non-critical care staff, with limited training and experience, to operate, as it is likely that they will be called on to help manage patients with respiratory failure in a mass casualty setting. Because it may also have to be used outside of an ICU, alternative PPV equipment must have appropriate alarm capabilities, battery power, and the ability to function with either high or low pressure oxygen sources. 

When new drugs and drug-delivery systems are developed in the laboratory, the correlation of the necessary production equipment may be very difficult indeed. For example, the shear needed to create the desired particle size of an emulsion with the help of laboratory equipment may pose serious problems in the selection of plant equipment necessary to reproduce the attributes of the product. Recording the speed of a laboratory mixer is not sufficient by itself for this task definition of the operating principle and equipment design is necessary to accomplish the task. 

A special feature of this book is the large number of numerical examples that have been worked out in detail. With very few exceptions these examples have been based on actual physicochemical data and many have direct relevance in equipment design. The worked examples can be used by the students for self-study and also to help digest the theoretical material. 

Investigations of industrial accidents reveal that most are caused by human error. The twentieth century s worst industrial disasters—Bhopal, Three Mile Island, and Chernobyl—helped clarify the complex chain of system problems that lead to human error. System problems are problems caused by a process system with built in design and operating deficiencies. The accidents provided numerous checklists and case studies for control room and equipment design. A partial list of some of the problems found at the industrial sites mentioned above are ... 

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