Air blast equipment

As a result of its use as an insecticide on fruit trees, vegetables, and other crops, endosulfan is released directly to the atmosphere during application. The compound is applied principally by air-blast equipment or boom sprayers (WHO 1984). No information was found in the available literature regarding atmospheric releases from manufacturing or formulation operations, or occurrence of the compound in air samples collected at NPL sites. 

In attempting to estimate the exposure of orchard workers, it could be presumed that, of the total amount sprayed, the amount that did not impinge upon the target or drift off would be available for contact on the worker. In a preliminary trial using air blast equipment, Chiba (1) found that 53% of the spray cloud hit the target, 13.5% fell to the ground and 33.5% remained in the air. 

This is somewhat surprising when one considers that air blast equipment, utilized in orchards, delivers a relatively small droplet spray cloud which one would expect to be readily respirable. The total mass of these droplets is small, however. 

There is information available on the droplet size generated from 3 of the more common nozzle types used on air blast equipment (13) The physical/chemical properties of the spray formulation and its end use dilution can have a marked influence on the droplet as it travels from the nozzle, resulting in a large decrease in diameter. There is presently inadequate information to enable accurate estimates of droplet size distribution at varying distances from the spray nozzle. These changes may not be important in estimating direct contact to the workers but become... 

It has been shown that for air blast equipment using 3 types of nozzles, no droplets exist below 5 microns (13). If however we arbitrarily assume 0.5% for purposes of calculation, the respirable concentration would be ... 

Exposure of Workers Using Air Blast Equipment from Patch Data and Hand Swabs or Hand Washes (6)... 

The removal of LSR parts is frequently performed with pneumatic support. For this, air blast equipment is required, including a pressure reducer, which allows the compressed air to be introduced only at the specified pressure. 

The blasting equipment and the air cleaning equipment may be placed outside or inside the room. 

Type of application equipment used for example, using over-the-top spray boom or air blast for grapes. The sprayer should be consistent with local cultural practices for each test site. 

The amounts of surface deposits resulting from commercial and experimental applications of DDT and parathion were ascertained on apples, pears, peaches, oranges, and lemons. Applications were made with conventional high pressure spraying equipment, utilizing manually operated guns or semiautomatic booms, and with two types of air blast sprayers. 

Comer et al. (2) therefore evaluated the effect of exposure to carbaryl (1-naphthyl methylcarbamate) on formulating plant workers and on workers applying carbaryl to fruit orchards with a tractor-drawn air-blast sprayer. However, information was still needed on the persistence of carbaryl in apple orchards and on the resultant exposure of workers who re-enter treated orchards. Further, no studies had been done on other types of crops. The present study was undertaken to determine the exposure of agricultural workers to carbaryl as a function of type of formulation, application equipment, application method, and type of work performed (i.e., mixer-loader, applicator, flagman, bystander, and apple thinners). 

Nothing much changed in iron or steelmaking for the next 200 years until the Bessemer process was introduced in the mid 1800s. In the Bessemer process, molten iron from the blast furnace was transferred to a separate refractory-lined vessel into which large quantities of cold air were blown to oxidize and remove the carbon. This was made possible by developments in air compression equipment. The modem steel age was bom. The availability of higher-quality, low-cost steel drove rapid expansion of the market for iron and steel and led to a rapid development of several new technologies. 

The mixer includes three air passages equipped with swirlers leading into the combustion chamber. The two central coaxial passages feature axial swirlers, while the external air passage heis radial swirling vanes. Air blast fuel atomizers... 

Site and Application Procedures. The orchard site and air application equipment were the same as described by Currier (1982). In 1980, ground applications were made with an Ag-Tech low volume air blast sprayer, calibrated to deliver 187 1/ha, and in 1981, with a Kinkelder low volume air blast sprayer calibrated to deliver 94.6 1/ha. From previous studies of MacCollom et al ( ) and Currier ( ) it was known that the air application gave a median droplet size diameter of 100 to 150 pm. Estimation of particle size, as measured on water sensitive paper, for ground equipment was 75 to 110 pm. Application rates for captan 80W in both years was 3.12(AI) Kg/ha, and for carbaryl 80S, 2.24(AI) kg/ha. 

Application Equipment Examples of application equipment are boom sprayers, airplane, air blast sprayer, backpack equipment and high pressure guns. Backpack and air blast operations appear to give greatest exposure to applicators. 

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