Mechanical Design Considerations

Most rotor-stator devices are equipped with variable speed drives to allow operations at different rotor speeds. There is sufficient know-how about variable speed drives. However, one must pay careful attention to  

The DR 3-13/CIP design carries 3A authorization number 846 for sanitary standards 

Tandem mechanicai seai combines benefits of singie and doubie mechanicai seais (singie mechanical seal with flush also available) 

Patent-pending food-grade Viton 0-rings between all stainless steel parts 

It is important to verify, a priori, that the specific equipment has been used at the specified conditions without any known problems. Because of the close tolerances or small gaps between the rotor and stator parts, one must confirm that the gap tolerances will be maintained as the components heat up during processing. 

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P. E. Glascow and A. A. Murica, "Process and Mechanical Design Considerations for ECC Regeneration Air Distributors," presented at Katalistiks... 

Sohds in divided form, such as powders, pellets, and lumps, are heated and/or cooled in chemical processing for a variety of objectives such as solidification or fusing (Sec. 11), drying and water removal (Sec. 20), solvent recoveiy (Secs. 13 and 20), sublimation (Sec. 17), chemical reactions (Sec. 20), and oxidation. For process and mechanical-design considerations, see the referenced sections. 

Mechanical Design Considerations The paper by Speechly et al., ( Principles of Total Containment System Design, presented at... 

Below we discuss briefly the constructional requirements and general manufacturing practices for cubicle-type switchgear and controlgear assemblies, and the electrical and the mechanical design considerations to comply with the above design parameters and service conditions. 

Where speed-increasing gears are a consideration, the 3,600-rpm motor is eliminated for all practical purposes because of higher cost, less favorable torque characteristics, and mechanical design considerations. 

The split-fraction coefficients can be estimated by considering the function of the process unit, and by making use of any constraints on the stream flows and compositions that arise from considerations of product quality, safety, phase equilibria, other thermodynamic relationships and general process and mechanical design considerations. The procedure is similar to the techniques used for the manual calculation of material balances discussed in Section 4.3. 

The PCU shaft speed response appears in Figures 18 and 19. There is an initial overshoot in the first second as the controller attempts to maintain 60 Hz. The overshoot dies out within three seconds and the speed returns to the set point value. The permissible magnitude and time rate of change of the overshoot is governed by mechanical design considerations. The constants in the PI speed controller can be modified as needed to reduce overshoot. Bypass flow rate shown in Figure 20 peaks at almost half of the full power PCU flow rate. 

Mechanical Design Considerations The paper by Speechly et al., ( Principles of Total Containment System Design, presented at 1. Chem. E. Northwestern Branch Meeting, 1979) discusses a number of pertinent design features, as follows ... 

Mechanical Design Considerations 3.5.1 Thermal and Mechanical Stress... 

Applicable Codes, Regulations, Standards, and Recommended Practices Mechanical Design Considerations... 

Mechanical design considerations seals, dynamic loads, rotating shafts, and critical speed... 

Reflector blanks, especially large ones, require special measures to maintain dimensional (surface) stability. The blank must be adequately supported to retain its shape under varying gravitational loads. It must also be stable during normal temperature cycles, and it should not heat the air in front of the mirror because that causes thermal turbulence and worsens the seeing. A mirror-to-air temperature difference less than about 0.5°C is usually acceptable. The support problem is a mechanical design consideration. Thermal stability may be approached in any of several ways ... 

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