Erosion problems

Tower shells may be ferrous, non-ferrous, stainless alloys or clad (such as monel-clad-steel). The trays are usually light gage metal consistent with the corrosion and erosion problems of the system. The velocity action of vapors flowing through holes and slots accentuates the erosion-corrosion problems, and often a carbon steel tower will use... 

No loss-of-circulation problem No formation damage Very high penetration rate Low bit costs Low water requirement No mud requirement No ability to counter subsurface pore pressure problems Little ability to carry formation water from hole Hole erosion problems are possible if formations are soft Possible drill string erosion problems Downhole fires are possible if hydrocarbons are encountered (gas only) Specialized equipment necessary... 

Cavitation in pipe systems is possible wherever there are changes in section or flow direction such as expansions, bends and branches. However, serious erosion problems are normally only associated with components within which flow is severely constricted and consequently accelerated. If pumps are excluded then, in most systems, this situation applies to devices used... 

Because economizer tube bundles produce very hot FW within the tubes, they may be subject to serious waterside corrosion and deposition problems, in addition to gas-side dust erosion problems and cold-end acid attack from sulfuric acid (derived from sulfur-containing fuels). 

Consideration will now be given to the various flow regimes which may exist and how they may be represented on a Flow Pattern Map to the calculation and prediction of hold-up of the two phases during flow and to the calculation of pressure gradients for gas-liquid flow in pipes. In addition, when gas-liquid mixtures flow at high velocities serious erosion problems can arise and it is necessary for the designer to restrict flow velocities to avoid serious damage to equipment. 

Environmental aspects suggest replacing barite with ilmenite. However, the use of ilmenite as weighting material can cause severe erosion problems. Using ilmenite with a narrow particle size distribution around 10 p can reduce the erosion to a level experienced with barite [1543]. 

Erosion in the nozzle or orifices is often associated with weepage of solids. This can be avoided by carefully designing a grid with the proper pressure drop criteria as presented in Sec. 3.2. Poorly designed bubble caps tend to have erosion problems due to the secondary circulation of solids. Therefore, bubble caps should be designed to minimize secondary circulation of solids. 

While some of the WEB drawbacks can be eliminated by W CMP, W CMP itself generates new problems. Because W CMP uses alumina (AI2O3, one of the hardest materials known) abrasive in a Fe(N03)3-based slurry to polish, defectivity (scratches) and Fe contamination become issues. For the former, oxide buff can be used to reduce defects. However, this may lead to an oxide erosion problem, as discussed in a later section. 

Which two parameters influence the erosion problems in gun barrels the most ... 

The thermal efficiency of this cycle is that of a Carnot engine, given by (5.8). As a reversible cycle, it could serve as a standard of comparison for actui steam power plants. However, severe practical difficulties attend the operatk of equipment intended to carry out steps 2 3 and 4 1. Turbines that take i saturated steam produce an exhaust with high liquid content, which causes sevel erosion problems, t Even more difficult is the design of a pump that takes in mixture of liquid and vapor (point 4) and discharges a saturated liquid (poll 1). For these reasons, an alternative model cycle is taken as the standard, at lei for fossil-fuel-buming power plants. It is called the Rankine cycle, and diSei from the cycle of Fig. 8.2 in two major respects. First, the heating step 1 2 ... 

Composite ceramic monolith catalysts are also included among the commercial SCR systems. They are manufactured by depositing a layer of catalytic ingredients onto strong, thin-walled ceramic honeycomb supports (usually cordierite). They may suffer from erosion problems in the presence of dust, and their use may be preferably limited to a clean environment. 

Tronconi and Forzatti [39] have shown that increasing the channel hydraulic diameter dn adversely affects the NO conversion by enhancing the resistances to transport of the reactants from the bulk gas phase to the catalyst surface. Conversion of SO2, instead, 1 unaffected by df due to the absence of diffusional Imutations However, the realization of small channel openings guarantees the achievement of a specific NO, abatement level with a reduced amount of catalyst and is consequently associated with a lower SO2 conversion [44] It must be noted that selection of the channel size has to account for plugging and erosion problems, too... 

Plantings of various kinds have proven to be cost-effective alternatives to remedy slope stability and erosion problems. A minimum of simple and readily available equipment is needed for the installation of plantings. Trained personnel, however, are required in order to reap the maximum benefit. 

Previous research on acid deposition effects on wood coatings did not take into account the effect of the substrate but linked poor performance in acid environments to the extenders in the paint. It should be relatively easy to formulate paints to overcome this erosion problem. However, in wood it is catastrophic failure that causes most poor-paint performance. Thus, the effect of acids on this interface failure should be addressed in future work. 

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