Irrigators

Mesh beds of knitted wire mesh, plastic, or glass fibers are used for the removal of Hquid particulates and mist. They will also remove soHd particles, but win plug rapidly unless irrigated or flushed with a particle-dissolving solvent. 

Fig. 22. Performance cut diameter predictions for typical dry packed bed particle collectors as a function of bed height or depth, packing diameter and packing porosity (void area) S. Bed irrigation increases collection efficiency or decreases cut diameter (271). SoHd lines, = 25 mm dashed lines,...

Venturi scmbbers can be operated at 2.5 kPa (19 mm Hg) to coUect many particles coarser than 1 p.m efficiently. Smaller particles often require a pressure drop of 7.5—10 kPa (56—75 mm Hg). When most of the particulates are smaller than 0.5 p.m and are hydrophobic, venturis have been operated at pressure drops from 25 to 32.5 kPa (187—244 mm Hg). Water injection rate is typicaUy 0.67—1.4 m of Hquid per 1000 m of gas, although rates as high as 2.7 are used. Increasing water rates improves coUection efficiency. Many venturis contain louvers to vary throat cross section and pressure drop with changes in system gas flow. Venturi scmbbers can be made in various shapes with reasonably similar characteristics. Any device that causes contact of Hquid and gas at high velocity and pressure drop across an accelerating orifice wiU act much like a venturi scmbber. A flooded-disk scmbber in which the annular orifice created by the disc is equivalent to a venturi throat has been described (296). An irrigated packed fiber bed with performance similar to a... 

For addition of fertilizer to irrigation spray systems, complete water solubiHty, and hence use of the solution-type fertilizers, is essential. An additional requirement is that the fertilizer be of a composition that does not react with the normal mineral content ie, the hardness, of the irrigation water to form objectional scaling of equipment. 

Yields as high as 45 t/hm yr have been observed on experimental test plots in Elorida, and it has been suggested that similar yields could be achieved in the Southwest with irrigation. 

The discovery of chemical N2 fixation under ambient conditions is more compatible with a simple, complementary, low temperature and low pressure system, possibly operated electrochemically and driven by a renewable energy resource (qv), such as solar, wind, or water power, or other off-peak electrical power, located near or in irrigation streams. Such systems might produce and apply ammonia continuously, eg, directly in the rice paddy, or store it as an increasingly concentrated ammoniacal solution for later appHcation. In fact, the Birkeland-Eyde process of N2 oxidation in an electric arc has been... 

Article of Manufacture. An article of manufacture is an iavention such as a two-headed tooth bmsh, an iatravenous fluid bag, or an optical fiber "made" by a machine. One example of an iavention which could be considered an article of manufacture is U.S. Patent No. 5,241,990 tided "Irrigation/Aspiration Valve and Probe for Laparoscopy" (2). 

Magnitude of the residue in potable water, fish, irrigated crops Magnitude of the residue in food handling estabHshments... 

Shipments of concrete pipe in 1990 had a value of > 1.6 billion dollars. Much of this piping was for storm and sanitary sewers, culverts, and irrigation piping. Pressure piping sales were close to 300 million. There are a large number of manufacturers of concrete pipe since much of the pipe is produced reasonably close to the point of use. 

Data on selenium in water are limited. The drinking water content is usually less than 1 )-lg/L, and seldom exceeds the 50 )-lg/L upper limit estabhshed in 1993 by the U.S. EPA (23). It may be higher in wells in seleniferous areas, and markedly higher in some river waters where irrigation drainage from seleniferous soil contains up to 2680 )-lg/L. 

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