Spraying machinery

The key properties of the spray dispersion that influence the size of the droplets formed are its dynamic surface tension and its viscosity (Elliott and Wilson, 1983 Dexter and Huddleston, 1998) although it should be noted that poor spray machinery setup and use can play a more important role than the physical properties of the spray dispersion (Spray Drift Taskforce, 1977). 

Aerosol products are hermetically sealed, ensuring that the contents caimot leak, spill, or be contaminated. The packages can be considered to be tamper-proof. They deUver the product in an efficient manner generating Httie waste, often to sites of difficult access. By control of particle size, spray pattern, and volume deUvered per second, the product can be appHed directiy without contact by the user. For example, use of aerosol pesticides can minimize user exposure and aerosol first-aid products can soothe without applying painful pressure to a wound. Spray contact lens solutions can be appHed directiy and aerosol lubricants (qv) can be used on machinery in operation. Some preparations, such as stable foams, can only be packaged as aerosols. 

Avoiding sick building syndrome requires special consideration of building constmction and maintenance material used. Asbestos, organic solvents, paint sprays, dirty filters, moist environment caused by poorly maintained humidifiers, and dirty HVAC machinery have contributed to the deterioration of indoor air quahty. Nonstop quahty maintenance is required at all times. 

Hard facing of various components in the aircraft gas-turbine engine and in industrial apphcations for textile machinery parts, oil and gas machinery parts, paper-shtting knives, etc, is estimated at 1 x 10 in 1995 with an estimated growth rate of 5% annually. The mix is approximately 45% aerospace apphcations, 55% industrial apphcations. Additionally, repair coatings for gas-turbine blades and vanes is estimated at 500 x 10 . These coatings are primarily deposited by plasma spray, arc-wire, HVOF, and detonation gun techniques. 

Few plant operators need to be told of the problems caused by water in compressed air. They are most apparent to those who operate pneumatic tools, rock drills, automatic pneumatic powered machinery, paint and other sprays, sandblasting equipment, and pneumatic controls. However, almost all applications, particularly of 100-psig power, could benefit from the elimination of water carryover. The principal problems might be summarized as ... 

To obtain some idea as to the actual vertical penetration of TCDD in those areas contaminated by dispersion, three sample points were selected near the farm road which was sprayed in 1971. At each point a single sample was collected from each of three depths, viz, at the 0- to 2-, 2- to 4-, and 4- to 6-inch depths, using clean knives and spoons. The selection of a 2-inch increment was based upon the estimated removal on a single pass by a qualified operator of earth-moving machinery. The resulting data are as follows ... 

Apples. The Rome Beauty apples used in the wash tests were sampled from trees that had received varying amounts of DDT mixtures in as many as six cover sprays. Duplicate or triplicate samples of 30 apples each were taken at random for the residue analyses from the fruit passed through each experimental wash mixture. Additional lots of 30 washed apples each were placed in cold storage for subsequent examinations. Unless otherwise indicated, all washing tests were run in a flood-type washer of recent design (a BADD washer with a heated prewash tank unit, an unheated main tank unit, a water rinse tank unit, and a velour roller dryer unit, manufactured by the Bean-Cutler Division, Food Machinery Corporation, San Jose, Calif.). Surface deposits of DDT were determined as described (10, 12) on samples taken just before and immediately after the washing treatments. 

Cook, E.M. Estimating Spray Drying Costs, Chemical Engineering Progress, June 1966, p. 93. Block, L.J. Estimating Machinery and Equipment, Erection Costs, Oil and Gas Journal, Aug. 6, 1973, p. 77.. 

Fixed water spray systems are most commonly used to protect flammable liquid and gas vessels, piping and equipment, process structures and equipment, electrical equipment such as transformers, oil switches, rotating electrical machinery, and openings through which conveyors pass. The type of water spray will depend on the nature of the hazard and the purpose for which the protection is provided. 

Group II category 1G electrical and non-electrical apparatus, machinery, electrostatic spraying tools, safety systems... 

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