Sprays, targeting

View of the typical conventional Cl-engine spray targeting from the bottom. The images of the nonevaporative spray were obtained in an engine with a transparent piston top, using a fast camera and a pulsed laser for iUuminating the sprays from the same side as the camera. (From Cronhjort, A. and WahHn, F., Appl. Opt., 43(32), 5971,2004. With permission.)... 

Arable crops are normally considered as being plane or two-dimensional spray targets. Pesticide label recommendations for arable crops usually define doses and application methods, with little regard for the development of the crop. Limited application specifications such as apply 11/ha in 2001/ha of water using a boom sprayer are ubiquitous. 

Shi Y. 2008. Optimization study of the effects of bowl, spray targeting and swirl ratio for a heavy-duty diesel engine operated at low and high load. IMech E 9 325 6. 

Koehler E, Tomazic D, Adomeit P (2010) Exhaust injector spray target. US Patent 7,788,907, 7 Sept 2010... 

Includes cyclonic, dynamic, filtration, inertial impaction (wetted targets, packed towers, turbulent targets), spray chambers, and venturi. 

Fig. 18. Target efficiency of a single water droplet in a gravitational spray tower (278,279). From Ref. 280,...

Fig. 20. Spray droplet target efficiency in a centrifugal spray tower with a centrifugal field of 100 g (140,281).

The different types of furniture pohshes include hquid or paste solvent waxes, clear oil pohshes, emulsion oil pohshes, emulsion wax pohshes, and aerosol or spray pohshes (3). Nonwoven wipes impregnated with pohsh ingredients have been targeted at consumers who do not wish to expend the time to dust before polishing (11). Compilations of representative formulas are given in References 3, 4, 12, and 13. Paste waxes contain ca 25 wt % wax, the remainder being solvent. Clear oil pohshes contain 10—15 wt % oil and a small amount of wax, the rest being solvent. Aerosol or spray products may contain 2—5 wt % of a sihcone polymer, 1—3 wt % wax, 0—30 wt % hydrocarbon solvent, and ca 1 wt % emulsifier. The remainder is water. 

In agricultural spraying, one of the biggest concerns is the drifting of small droplets. Drifting sprays not only lead to waste and environment problems, but also could endanger other nearby crops. Droplets smaller than 150 p.m can be easily blown away from the intended target area by a cross wind. A typical herbicide atomizer produces a spray with 15—20% of the Hquid volume contained in droplets less than 150 p.m. Atomizer improvements must be made so that the spray contains a narrow droplet size distribution with Hquid volume less than 5% contributed by the smaller droplets. 

Figure 11-69 describes a typical central system. Either water or direct-expansion refrigerant coils or air washers may be used for cooling. Steam or hot-water coils are available for heating. Humidification may be provided by target-type water nozzles, pan humidifiers, air washers, or sprayed coils. Air cleaning is usually provided by cleanable or throwaway filters. Central-station air-conditioning units in capacities up to about 50,000 cu ft/min are available in prefabricated units. 

Ejfect of Gas Saturation in Scrubbing If hot unsaturated gas is introduced into a wet scrubber, spray particles will evaporate to cool and saturate the gas. The evaporating liquid molecules moving away from the target droplets will repel particles which might collide with them. This results in the forces of diffusiophoresis opposing particle... 

A matter of considerable importance in the selection of an application method is its efficiency. Spray techniques are usually inefficient, since many droplets drift past the target and are lost. Even electrostatic spraying can waste as much as 35% of the paint. There is some loss of paint in most methods, but roller coating, curtain coating and electrodeposition are very efficient. Electrodeposition is also a very useful technique where corrosion resistance is important, since it applies a uniform coating over nearly all surfaces of even the most complex-shaped article. 

One problem that has arisen with the use of herbicides in agriculture is spray or vapor drift. When fine spray droplets are released, especially if applied aerially, they may be deposited beyond the target area due to air movements to cause damage there. In the first place, this is a question of application technique. Herbicides, like other pesticides, should not be applied as sprays under windy conditions. In most... 

The key challenge to SCSI engine operation is successful fuel stratification in the combustion chamber. Three methods for this stratification are commonly referred to as wall guided, air guided, and spray guided [15]. Wall-guided systems utilize injector targeting at specific features (such as the piston) to achieve a reliable fuel... 

Total enclosure Wet scrubbing Absorption tower Fluidized bed scrubber Impingement scrubber Irrigated target scrubber Pressure spray scrubber Rotary scrubber ... 

A field test was conducted by spraying a commercial oil spill-dispersant (Corexit 9527) from aircraft [696]. Test objectives were to determine the efficiency of delivering the dispersant to a selected target using a large aircraft and to compare various measurement systems for droplet size and spray pattern distribution. The results indicated that aerial flights up to 46 m can produce droplet sizes and swath widths that would be operationally effective for an oil spill. 

---