Pumping equipment selection

Most chromatographers limit themselves to binary or tertiary gradient systems however, it should be noted that pumps capable of quaternary gradient are available (see reference 3, Chapter 3) and should be considered in the equipment selection process to allow greater versatility in method development. 

During the design phase, all of the data derived from the hydraulic characterization are evaluated for use in the selection of recovery pumping equipment and for the determination of the most appropriate subsurface fixtures (whether wells, trenches, or drains, etc.). A variety of generic scenarios may be appropriate to optimize product recovery. If the product thickness is sufficient, the viscosity low, and the formation permeable, a simple pure-product skimming unit may be the best choice. Other combinations of permeability, geology, and product quality will require more active systems, such as one-pump total fluid, or two-pump recovery wells. 

Select a 10-gpm positive displacement pump, carbon steel construction. A summary of the equipment needs for the alkylation unit in this preliminary process design is presented in Table 1. The preparation of similar equipment lists for the other process units completes the equipment selection and design phase of the preliminary design. Figure 2-5 shows a simplified equipment diagram for the proposed process and includes the specified size or capacity of each piece of process equipment. 

Draft specifications for equipment selection pump design... 

Certificate of Compiiance A certificate of compfiance shall be included if specified. This certificate of compliance shall include the necessary evidence and assurance that the pump supplied is being supplied according to the requirements of this Standard and meets additional requirements identified in the purchaser s specification and purchase order. It shall be the purchaser s responsibility to select the manufacturer that is capable and qualified to supply the specified pumping equipment and that maintains the proper credentials for supplying the certificate of compliance. 

For a particulate application involving SLS, how to choose the best equipment, to use batch or continuous operation, which filter medium to select, and what is the optimum operating conditions are concerns of engineers. Although theories are available for some SLS operations, solutions for equipment selection, process design, and optimization are still very much dependent on test and experience, and are frequently qualitative or semi-qualitative. In this section, strategy and decision networks for selection of SLS equipment, introduction of filter media, centrifugal pumps for filtration operation, and selection of filter aids by cycle analysis will be discussed. 

The first design of LIS (Figure 1.27) [30] consisted of an automatic syringe pump equipped with a three-way solenoid valve at the head and two optical fibers mounted to the syringe, enabling the whole procedure (i.e. microextraction and detection) inside a glass syringe, connected to the central port of a selection valve. 

CLOSED. All equipment selected for compliance with aircraft req. Vacuum pumps used for filling are brushless and/or operated on the ground only. Chiller compressor electronics modified to use solid-state relays to eliminate any potential for sparking. 

The variety of expert systems in the field of equipment selection is very large. Examples are pumps, compressors, control equipment, column internals, reactors, valves, absorbers and extractors. The structure of these selection systems is often very similar. The knowledge base contains a set of objects (similar to an equipment list). For each of these equipment items a list of criteria is available which allows the user to decide whether the object can be used or not. Moreover, a ranking list can be derived from a set of evaluation criteria. 

K. Equipment selection (e.g., pumps, air handling units, chillers, boilers)... 

To select the best method of storage and mixing and to size injection pumps, it is necessary to calculate the chemical injection rate. The following method provides an estimate of chemical usage based on the reaction stoichiometry. Specific chemical suppliers and equipment manufacturers should be contacted to assist in making final equipment selections. 

Pilot plant can also avoid pitfalls in equipment selection. The two rheograms on figure 11 show how a screw type pump can affect the rheological properties of silica-alumina hydrogel. The shear stress imposed by the rotor-stator couple of the pump results in an increase of the yield value of the hydrogel. In the pump, the size of the particles which compose the hydrogel is decreased by a milling effect and the forces of cohesion are increased. This can stop the flow if the pump characteristics have been underestimated. This results also in modification of the gel structure and ability to be spray dried. 

---