Pipelines, flow improvers

N. E. Almond. Pipeline flow improvers. In Proceedings Volume, pages 307-311. API Pipeline Conf (Dallas, TX, 4/17-4/18), 1989. 

Correlations for E are not widely available. The more accurate model given in Section 9.1 is preferred for nonisothermal reactions in packed-beds. However, as discussed previously, this model degenerates to piston flow for an adiabatic reaction. The nonisothermal axial dispersion model is a conservative design methodology available for adiabatic reactions in packed beds and for nonisothermal reactions in turbulent pipeline flows. The fact that E >D provides some basis for estimating E. Recognize that the axial dispersion model is a correction to what would otherwise be treated as piston flow. Thus, even setting E=D should improve the accuracy of the predictions. 

C. L. Muth and S. M. Kolby. Cost saving by use of flow improver. In Proceedings Volume, pages 353-357. 13th Int Pipeline Technol Conf (Houston, TX, 2/5-2Z7), 1985. 

Large-scale applications are limited because of the sensitivity of polymers to chemical, thermal, and/or mechanical degradation (Martischius). Thus, the use of polymers should either be limited to open-ended systems with short distances to be covered (such as in the use of water hoses in fire fighting) or an additional injection device must be used in pipeline transportations, to automatically adjust the content of (fresh) flow improvers in case of decreased effectiveness. 

A similar application of DRA has been imdertaken to oil being piunped from the offshore platforms to shore facilities (217). Since 1983, some pipelines have used DRA for pipeline transportation of refined petroleum products (213). Treated fluids include gasoline, diesel, heating oil, and C4 carbon. Today, approximately 100 pipeline sites use DRA for increased throughput (213,214). Topical dose rates for 10-30% flow improvement in these pipelines are no more than 1-2 ppm polymer per inj ection. Tests indicate excellent drag reduction without adverse effect on engine (218). In 1994, DRAs were 14 times more effective than the initial material used in TAPS in 1980. 

A common example of foam formation in the bottom of a fractionator inducing flooding occurs in a crude preflash tower. In this case, stable foam accumulates in the bottom of the column as a consequence of the "flow improver" chemicals added to crude oil. These chemicals reduce pressure drop in the crude pipelines. Once the foam level rises to the feed inlet nozzle, the trays flood and black distillate is produced. Please see Chapter 18 (Preflash Towers). 

AU of the above examples are agile supply chains, and each is dominated by a key player. The characteristics of an agile supply chain are quick customer response at each level of the chain, flexibihty, scheduling triggered by customer demand, open and real-time information flow, simultaneous new product development, and as Morgan (2004) says pipeline cost improvements. If agile is to be achieved measurement and control, or at the least monitoring of performance, is necessary. 

Technetium is also used as an alloy metal to produce super-strong magnets that are supercooled to near absolute zero to improve their efficiency. Powerful magnets are used in imaging equipment and possibly in future magnetic driven trains. Its radioactivity makes it useful as a tracer in the production of metals and tracing flowing fluids in pipelines. 

A sharp decrease in wall friction in the flow of visco-elastic liquids (including chemically reactive liquids) leads to the formation of low pressure zones. The gas flows into these zones, which leads to disruption of the liquid stream in nozzle 5. Additional gas blown into the disrupted liquid stream through the ring gaps by pipelines 11 and 15 causes separation of the liquid into smaller droplets, thus improving spray dispersion. 

Figure 3.3 A qualitative process pipeline model, illustrating the elimination of unsuccessful drug candidates at earlier stages. Qualitative improvements in efficiency and the rate at which drug candidates flow through the pipeline result from the incorporation of new applications for drug candidate evaluation at earlier stages of drug development. (Courtesy of Milestone Development Services, Newtown, Pa., USA.)...

In recent years, the process has been modified to increase the yield of lower olefines, too. Continually improved since then, especially in the mid-1960s with the replacement of the original silica-alumina catalyst by a zeolite. The catalyst is now typically a zeolite Y, bound in a clay matrix. The feed is vaporized and contacted in a pipeline reactor with concurrently flowing microspheroidal catalyst particles. The catalyst is then separated from the hydrocarbon products and is continuously regenerated by burning off the coke in a fluidized bed. The process is licensed by UOP several hundred units are in operation worldwide. See also HS-FCC. 

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