Erosion protection

Before leaving this section we wish to point out that the outer horn deflection mechanism described above also applies to the innermost horn segment, as one might expect. Hence, solids may also impact the inside wall of the inlet scroll or barrel, depending on the design. However, as mentioned above, these surfaces are almost always covered with erosion resistant, protective liners and, for this reason, their wear rates may not be noticeable or significant. What may be significant, however, and what may not be fully appreciated, is the effect that the particle behavior described above has on cyclone separation performance. This is another area that appears to have received virtually no attention by the research community. 

Given sufficient time, most cyclones will experience sufficient erosive wear that they must either be replaced or repaired. If the service life of the cyclone is deemed imacceptable, one has two basic options for ameliorated erosive wear one is to reduce the velocities within the cyclone the other is to render the cyclone less vulnerable to erosive attack through hardware modifications. Reducing velocities, namely by increasing the inlet and/or gas outlet areas, is seldom a viable option, at least not after the unit has been built since. 

installation of wear plates ( permanent or removable, internal or external) 

replacement of worn sections with heavier gauge metal or thicker plate 

replacement of eroded sections of the cyclone with harder, more abrasion resistant materials of construction (MOC) 

---

The expander turbine is designed to minimize the erosive effect of the catalyst particles stiU remaining in the flue gas. The design ensures a uniform distribution of the catalyst particles around the 360° aimulus of the flow path, optimizes the gas flow through both the stationary and rotary blades, and uses modem plasma and flame-spray coatings of the rotor and starter blades for further erosion protection (67). 

Depending on the material type and construction method, the saturated hydraulic conductivities for these barrier layers are typically between 1 x 10-5 and 1 x 10-9 cm/s. In addition, conventional cover systems generally include additional layers, such as surface layers to prevent erosion protection layers to minimize freeze/thaw damage internal drainage layers and gas collection layers.6 22... 

Y. Gudimenko, Z. Iskanderova, J. Kleiman, G. Cool, D. Morison and R. Tennyson, Erosion Protection of Polymer Materials in Spaice, 7th International Symposium on Materials in a Space Environment, held in Tolouse, France, 16-20 June 1997, ESA Special Publication 399, Ed. T. D. Guyenne (European Space Agency, Paris, Prance, 1997) pp. 403-410. 

Oil loss may occur from pipeline rupture caused by corrosion, subsidence or land slip, or from seismic disturbances [82]. Regularly scheduled inspections of pipeline rights of way, and efficient containment and cleanup operations can keep these losses small. Diking of any pipeline rights of way alongside a lake, stream, or maritime coast at the time of construction can be a useful precaution. This can be aesthetically blended into natural contours, and seeded for erosion protection. 

SWPPP phase I applies to industrial facilities and to construction sites affecting more than 5 land acres, while SWPPP phase II regulations affect those construction sites affecting between 1 and 5 acres. SWPPPs are expected to provide plans for minimization of soil erosion, protect vegetation and wetlands, and define runoff source points to standing water. 

The stubble-mulch system is a variation of the complete mulch system (see Chapter 25). Such a mulch seldom covers all of the soil surface, and hence does not absorb all of the raindrop energy. Nevertheless, it is very effective and, furthermore, helps to retard the movement of flowing water. Obviously, the heavier the preceding crop, the better the soil coverage by the mulch is likely to be, and the greater the erosion protection. Any exposed soil may be puddled, but that under the residues is free to absorb water at a rate little affected by the rain. Many experiments have shown that as little as 700 lb. of straw... 

Excellent corrosion and erosion protection have been obtained from a galvanized fence around a marketplace in the Hague. After 15 years of wear by bicycles, carriages, shopping carts, and so on, only the zinc layer had suffered. The Zn/Fe alloy layers remained intact. 

Stones, rocks, concrete blocks or other materials used for the erosion protection of a soil surface. 

Hemp straw jute in a variety of make-ups Thermal (25% bonding fibres), mechanical by partial needle-punching 1800 to 2200g/m Mulch mat, erosion protection... 

Figure 2.2 Decanter centrifuge (from Alfa-Laval, 1978). 1, Hollow drive shaft with stationary inlet tube 2, erosion protected solids discharge ports 3, tapered beach section of rotor for discharge of solids 4, solids deposited on rotor wall 5, screw conveyor 6, pond of clarified liquid 7, exchangeable overflow weirs 8, conveyer drive shaft from gearbox.

Erosion, coating worn away. Loss of coating due to inadequate erosion protection. Provide material with greater resistance to erosion. 

DLC coatings have recently reached the production stage with applications in wear and erosion protection and in optics. The cost is generally similar to that of carbide or nitride films deposited by CVD or PVD techniques. 

A. McClarty, J. Cross, L. Gilbert and O. M. James, Design and construction of coastal erosion protection groyne using geocontainers, Langebaan, South Africa. Proc. Int. Conf Geosynthetics, Yokohama, Japan (2006). 

Coatings - for a variety of applications requiring specific properties including wear resistance, corrosion resistance, high-temperature protection, erosion protection and combinations thereof. 

AI2O3 doped with MgO, Si02, Zr02, and TiC are strong and tough, finding uses in tool tips, mechanical mills, and erosion protection sheaths. 

The cake discharges at the rear of the beach, between the beach proper and the rear hub. In its simplest form, the cake discharge will he a series of radial holes around the beach end. These holes will usually be lined with some form of erosion protection, quite often in the form of a sintered tungsten carbide... 

The floe or rinse zone is a chamber in the conveyor hub behind the feed zone, sometimes separated by a buffer chamber to minimise cross contamination. The required throughput of this chamber is an order of magnitude less than that of the feed zone. Therefore, it does not require the same sophistication as the feed zone, nor does it require erosion protection. 

There can almost be an infinite number of feed zone designs with different shaped inlets and outlets, different number of outlets, erosion protection, accelerators and linings. 

---