Spraying placement

For the large refinery unit, spray placement and aiming was easier to do. In this case, the water-spray curtain was found effective in delivering water to the cloud. 

Spray tanks or hoppers. Granular products should be weighed before placement in application equipment. The time of preparation and application should also be recorded. 

Oncoming or cross wind effects may reduce the performance of water monitors. When winds of 8 km/hr (5 mph) are present they may reduce the range of water spray by as much as 50%. Consideration should be given to the placement of monitors when the normal wind speed is such to cause performance effects. 

The surface slope at the placement of all hydrants, monitors and hose reels should be slightly away from the device itself so water will drain away and prevent corrosion effects. Where automobile traffic may be prevalent, protective post or railing should be provided to prevent impacts to the devices. The protective barriers should not affect the hose connection, use of hoses or obscure the spray from monitors. The posts should be provided with highly visible markings or reflective paint. 

The placement of monitors should be cognizant of obstructions. The arc and depth of the spray coverage should be confirmed. 

Placement of detectors should consider the need for protection from physical damage, weather effects (snow, icing, wind-driven rain, or dust), or direct water hose spray during an area wash down. Detector placement should also allow safe access to perform required periodic testing and inspection. Typical approaches to flammable gas detection layout are ... 

Fixed water spray systems designed on an area coverage basis may also be used to wet/cool structural steel supports. In this case, the placement of discharge nozzles should be close, usually within 4 ft (1.2 m) of the steelwork being protected. Alternatively additional nozzles or a separate system may be provided. 

Flowers were produced by the unsprayed plants that were exposed for only 30 short days. This confirms that flowers had been initiated in the crowns of plants when sprays were applied after 30 short days and that these plants represented a different population from those sprayed immediately on placement under short-day conditions. One clearly evident result was a sharp reduction in number of flowers produced. The plants treated with 10 p.p.m. of potassium gibberellate, regardless of time, produced about one half as many flowers as the control plants. This was not observed in the field studies at the 10-p.p.m. concentration, but 40 p.p.m. of potassium gibberellate used three times in the field reduced yields by about one half. 

Preliminary results using a fluorescent tracer, which was added to the spray tank at the same time as the pesticide (Guthion WP), indicated that the distribution of the tracer, and presumably the pesticide, was not uniform, emphasizing the difficulty in the placement of the patches (2) This tracer technique is currently being evaluated as a tool for quantitative exposure estimation. This could result in a more realistic measurement of pesticide contact on the skin and minimize the reliance on extrapolation from the patch data. 

Heating the adhesive before atomization enables heavier adhesive buildup, reduces overspray losses, and minimizes contamination from atmospheric water vapor. Spray methods can be used on both small and large production runs. The liquid to be sprayed is generally in solvent solution. Sizable amounts of product may be lost from overspray. Two-component adhesives are usually mixed prior to placement in the spray gun reservoir. Application systems are available, however, that meter and mix the adhesive within the spray gun barrel. This is ideal for fast-reacting systems, but guns must be thoroughly cleaned to avoid buildup of polymerized product. 

An important feature of using these manual sprayers is that it is possible to do selective spot treatments, for example, confining the application of herbicides to patches of weeds. Also, where there is concern about downwind spray drift, placement of the nozzle nearer to the target and using a low pressure can enable treatments closer to a sensitive area. In conjunction with an attractant such as molasses or protein hydrolysate, insecticide bait sprays have been used in discrete spots for fruitfly control. Knapsack sprayers are often used in difficult terrain where access to vehicles is difficult or impossible. However, the lack of water in some situations, and the high requirement for labour, have created a demand for alternative application systems (see below). 

Placement spraying is widely used in the United States for applying most products using water volumes of around 100 litres/ha. In Australia, herbicides... 

A more recent attempt to control aerosol particle size on target has been the use of aerodynamic dissemination and sprays as line sources. Thermal dissemination, wherein pyrotechnics are used to aerosolize the agent has been used particularly to generate fine, inhalable clouds of incapacitants. Dispersion considers the relative placement of the chemical agent munition upon or adjacent to a target immediately before dissemination so that the material is most efficiently used. 

Acid extracts were combusted for 2 min in a Packard, Tricarb Model 306 sample oxidizer. Three 0.5-ml aliquots of each of the cooled sulfuric acid extracts were transferred into combustion cones containing a paper absorbent. About 0.1 g of Combust Aid was added immediately prior to placement in the combustion basket of the oxidizer. Labeled C02 was trapped in Carbo-Sorb (approx. 7 ml) and scintillation cocktail containing Permafluor V (about 13 ml). Radioactivity was measured by liquid scintillation analysis in a Beckman LS 6800 counter and corrected for efficiency and recovery. Data collected as dpm s were converted to mg based on the amount of paraquat ion in the original spray solution. 

Spray characteristics influence nozzle placement. Figure 8.13a through c indicate gun positioning concerns for multinozzle configurations. Ideally, sprayed material extends uniformly across the par-ticle/tablet bed as shown in Figure 8.13c. Undesired deviations from uniformity include the following ... 

Several processing concerns can result in poor coating uniformity. Guns positioned or operated such that spray patterns overlap too much or too little will result in over wetted or under wetted areas of the spray line. Also, spray should extent all the way to near the edges of the bed. Any shortcomings in gnn placement can affect coating uniformity depending on the extent that particle/tablet... 

The predominant variation from the typical flehmen response that has been observed involves a sideways twisting of the trunk and placement of the tip containing the urine on the dorsal palate at the junction of the hard and soft palates. This response (STR) has been observed 173 times. Another unusual flehmen response observed involves the use of the tongue to press materials onto the VNO, seen in one female and one male. Two bulls have been observed on three occasions each to spray a sample onto the VNO openings. Samples were often blown on if frozen or dried sometimes a flehmen response was elicited to dry or frozen samples without prior blowing to warm or dampen the sample. 

---