High pressure, troubleshooting

Because of the dependence on force or pressure, the entire technology is typically subdivided into low-, medium-, and high-pressure agglomeration techniques (Chapter 5). Since low-, medium-, and high-pressure methods, their equipment, and product characteristics are totally different, in the context of optimization and troubleshooting they will be covered in two separate sections below. 

Binder Interaction 601 Equipment Type and/or Size 601 Optimization 602 Troubleshooting 604 Pressure Agglomeration Technologies 616 Low- and Medium-Pressure Methods 618 High-Pressure Agglomeration Methods 621 Other Technologies 630... 

The advantages of locating the high pressure alarm nozzle (PAH) and the pressure controller (PRC) on their own dedicated %-inch connections is that each device can be individually isolated, tested, and its nozzle cleared by the outside operator without interfering with the function of the relief valve. I have discussed these procedures in detail in my book. Troubleshooting Process Plant Control (Wiley, 2009). 

Problems that arise with HPLC experiments are usually associated with abnormally high or low pressures, system leaks, worn injectors parts, air bubbles, or blocked in-line filters. Sometimes these manifest themselves on the chromatogram and sometimes they do not. In the following subsections, we address some of the most common problems encountered, pinpoint possible causes, and suggest methods of solving the problems. You can also refer to the troubleshooting guide in Chapter 12 for possible solutions. 

Hollow fiber modules, or permeators, are precisely machined units containing bundles of hollow fine fibers positioned parallel to and around a perforated center feed-water tube, with only one or two bundles per pressure vessel. They are widely used for brackish and seawater applications. Hollow fiber modules exhibit a low flux rate (permeate flow per unit membrane per unit time) and can foul easily but tend to have high conversion factors (the percentage of feed flow converted to permeate), typically 50 to 55%. This makes them suitable for both small and large RO systems. They are easy to troubleshoot, and bundles are easy to change in the field. 

Frasca, V. Troubleshooting high back pressure. Sci. Tools Pharm. Biotech. 1997, 2, 3. 

Pressure. The higher the pressure, the better the definition. Pressure should always be high. However, purging within the air line can cause forming problems and it is better to have an accumulator within the forming unit, which helps to troubleshoot the problem. 

FIGURE 13-3 Pressure survey is key to troubleshooting high Hash-zone pressure. 

Vacuum tower wash oil, 165 Vacuum lowers, 281—300 bottoms-pump suction pressure loss, 281— 285 high flash-zone pressure, 285-288 ejector problems, 288-292 black gas oil, 292-293 trim gas oil production, 293 pumparound draw temperatures, 293 light resid, 294 steam-to-healer passes, 295-297 gas-oil recovery improvement, 297-298 transfer-line failures, 298-299 troubleshooting problems, 299-300... 

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