Equipment design controls

Task characteristics (e.g., equipment design, control panel design, job aids)... 

Normally, (liquid) binder(s) is (are) required Green (wet) agglomerates with low initial strength Post-treatment for final strength and properties Simple equipment design Control depends largely on operator experience Difficult to clean (danger of cross-contamination)... 

Extraction, a unit operation, is a complex and rapidly developing subject area (1,2). The chemistry of extraction and extractants has been comprehensively described (3,4). The main advantage of solvent extraction as an industrial process Hes in its versatiHty because of the enormous potential choice of solvents and extractants. The industrial appHcation of solvent extraction, including equipment design and operation, is a subject in itself (5). The fundamentals and technology of metal extraction processes have been described (6,7), as has the role of solvent extraction in relation to the overall development and feasibiHty of processes (8). The control of extraction columns has also been discussed (9). 

Kngineering design of equipment and control of operatiag coaditioas is discussed hereia. 

Spreadsheet Applications. The types of appHcations handled with spreadsheets are a microcosm of the types of problems and situations handled with fuU-blown appHcation programs that are mn on microcomputers, minis, and mainframes and include engineering computations, process simulation, equipment design and rating, process optimization, reactor kinetics—design, cost estimation, feedback control, data analysis, and unsteady-state simulation (eg, batch distillation optimization). 

Inherently Safer Design Rather than add on equipment to control hazards or to protect people from their consequences, it is better to design user-friendly plants which can withstand human error and equipment failure without serious effects on safety, the environment, output, and efficiency. This part is concerned with this matter. 

For many years the usual procedure in plant design was to identify the hazards, by one of the systematic techniques described later or by waiting until an accident occurred, and then add on protec tive equipment to control future accidents or protect people from their consequences. This protective equipment is often complex and expensive and requires regular testing and maintenance. It often interferes with the smooth operation of the plant and is sometimes bypassed. Gradually the industry came to resize that, whenever possible, one should design user-friendly plants which can withstand human error and equipment failure without serious effects on safety (and output and emciency). When we handle flammable, explosive, toxic, or corrosive materials we can tolerate only very low failure rates, of people and equipment—rates which it may be impossible or impracticable to achieve consistently for long periods of time. 

Design procedures which result in a failure to identify hazards until late in design. By this time it is impossible to avoid the hazard and all that can be done is to add on complex equipment to control it. 

Model Development PreHminary modeling of the unit should be done during the familiarization stage. Interactions between database uncertainties and parameter estimates and between measurement errors and parameter estimates coiJd lead to erroneous parameter estimates. Attempting to develop parameter estimates when the model is systematically in error will lead to systematic error in the parameter estimates. Systematic errors in models arise from not properly accounting for the fundamentals and for the equipment boundaries. Consequently, the resultant model does not properly represent the unit and is unusable for design, control, and optimization. Cropley (1987) describes the erroneous parameter estimates obtained from a reactor study when the fundamental mechanism was not properly described within the model. 

Cyclic nature of Implement mechanical integrity program batch process (e.g.,, Design equipment for easy replacement start/stop, thermal cycling). Possibil- Consider demand of cycling while designing ity of mechanical equipment and controls wear and tear. Possible loss of containment. ... 

Physically differ- Standardize equipment and controls where possi-ent controls on ble when designing new facilities or upgrading similar equipment old ones in different, Provide training and procedures locations. ISA RP 60.3... 

Many processes require equipment designed to rigid specifications together with automatic control and safety devices. Consideration should be given to the control, and limitation of the effects, of equipment malfunction or maloperation including ... 

Provision of an adequately equipped emergency control centre of suitable design located outside potential danger zones. 

Older existing cartridge collector types have a range of actual operating efficiencies of 99 to 99.9% for PM,q and PMj j. Typical new equipment design efficiencies are between 99.99 and 99.999 -t- %. In addition, commercially available designs are able to control submicron PM (0.8 m in diameter or greater) with a removal efficiency of 99.999 + %. 

Is all equipment designed to totally contain the materials which might be present inside at ambient temperature or the maximum attainable process temperature (i.e., don t rely on the proper functioning of external systems such as refrigeration systems to control temperature such that vapor pressure is less than equipment design pressure) ... 

Determine the design controls you intend to impose over the design of test equipment, tools, test rigs, and other articles. 

Throughout these guidelines it is argued that when engineering techniques for the design and assessment of process equipment and control systems are supplemented with human reliability techniques, then performance of both the hardware and humans will be optimized. 

This technique sets out to collect data about near-incidents or critical events that have been experienced by the operating team but that are unlikely to be documented. The basic premise of the technique is that events that could have led to serious consequences would tend to be remembered by the workers. Through individual or group interviews, significant events are recalled which are then analyzed in order to generate useful information about the difficulties involved in the performance of a task, the adequacy of the operating procedures, any problems with the equipment or control panel design and so on. The technique can be used in three areas ... 

Design control Purchasing Process control Control of production Purchaser supplied equipment... 

Design Control Purchasing Process Control [Control of Production This group of requirements ensures that equipment is correctly designed and operated. Other elements will ensure compliance with the output from this group. 

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