Process selection design recommendations

Most screening machines are designed and fabricated such that their useful service lives are measured in decades rather than years in most applications. However, some applications can dramatically shorten service Ufe. Abrasive materials can cause premature wear, particularly when process rates are high. Some materials attack the screener s metal components. Salts, such as sodium chloride, calcium chloride, and ammonium sulfate, are particularly aggressive. In such cases, selection of the materials of construction is critical to maximizing screener service life. In this matter, it is best to work closely with the manufacturer, sharing all pertinent process parameters so recommendations can be made based on their experience with similar systems. 

Sttut your selection process by compiling a list of potential candidates. Contact your local branch of the American Institute of Architects (AlA) to obtain a list of firms in your area who specialize in industrieil facility design. Ask friends and business associates who have been through the process for their recommendations, fisit faciUties in your area that you admire and find out who designed them. If there are firms in your area that specialize in the type of stracture that you are planning, add them to your list. 

To develop an optimal PCB printing process, it is essential to consider all aspects of the process. The design of the board being produced, components being placed, materials used and selected equipment must work harmoniously. Suppliers realize that they must work together to develop recommended process parameters to satisfy the requirements of customers applications. 

Design practice breaks the overall problem into small component parts which allow for simple analysis and solution. This is the recommended approach for selection and sizing of process piping. 

In general, the final pump selection and performance details are recommended by the manufacturers to meet the conditions specified by the process design engineer. It is important that the designer of the process system be completely familiar with the action of each pump offered for a service in order that such items as control instruments and valves may be properly evaluated in the full knowledge of the system. 

The purpose of these 3 volumes is to present techniques of process design and to interpret the results into mechanical equipment details. There is no attempt to present theoretical developments of the design equations. The equations recommended have practically all been used in actual plant equipment design, and are considered to be the most reasonable available to the author, and still capable of being handled by both the inexperienced as well as the experienced engineer. A conscious effort has been made to offer guidelines to judgment, decisions and selections, and some of this will be found in the illustrative problems. 

A prototype system implemented with the Formulogic shell has recently been reported by Pfizer [21]. The system has been designed to use preformulation data on new drugs and recommend early development formulations, predict product properties, and select processing conditions suitable for scale-up. 

These four procedures are all recommended to be performed in the order shown to achieve optimal parameter estimation followed by a final validation of the gravity sewer process model (Figure 7.7). In the case of design of a new sewer system, procedure number 4 is, of course, not relevant and kinetic parameters for the sewer biofilm must be evaluated and selected based on information from comparative systems. 

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