Induction hoppers

A number of semi-automated systems for cleaning containers have been developed, and these are commonly operated in conjunction with induction hoppers - see below. 

INDUCTION HOPPERS AND OTHER PESTICIDE LOADING SYSTEMS... 

The low-level filling system that has become the most popular in Northern Europe is the induction hopper. This commonly comprises a bowl of approximately 0.5 m dimension into which chemical is poured manually. Most bowls now use a Venturi valve arrangement positioned at the base of the hopper to suck material from the bowl into a liquid flow, that is then directed to the main sprayer tank. An alternative direct connection of the induction hopper to the input side of the main pump is much less popular, because of the potential to damage the pump from extraneous materials that could be introduced via the hopper. A typical induction hopper design will therefore comprise ... 

A typical layout of an induction hopper system is shown in Figure 4.1. 

Figure 4.1 A typical layout of an induction hopper system, (a) Flow circuit diagram, (b) typical installation on a sprayer...

Container rinsing systems designed for use in conjunction with induction hoppers can be considered as being one of two basic types, namely ... 

Many tests of container rinsing performance associated with induction hoppers are conducted with the systems operating with clean water, whereas for many installations on practical sprayers the rinsing of the container uses liquid from the main tank. It is likely that the differences in residue levels associated with rinsing with clean water or tank contents will depend on the nature of the tank mix formulations, as well as on the design of the hopper and the container rinsing system. 

In the same way that it was recognised that a poorly designed induction hopper would not reduce the risks of operator and environmental contamination (see p. 49) and that a standard relating to system specification and performance was needed (Garnett, 1993) a standard relating to closed-transfer systems for liquid plant protection products has also been produced (Anon., 1996b). This follows the same format as the standard relating to induction hoppers and indicates that in order to comply with the standard, a closed-transfer system must... 

Anon. (1996a) British Standard BS 6365 Spraying Equipment for Crop Protection. Part 8, Specification for Induction Hoppers. 

Lichte FE, Hopper S, Osborn TW. 1980. Determination of silicon and aluminum in biological matrices by inductively coupled plasma emission spectrometry. Anal Chem 52 120-124. 

Hopper, A. and Hall, M. (1971) A new synthetic agent for the induction of ovulation preliminary trials in women. British Medical Journal, 1, 152—154. 

FIGURE 54.10 The ROTEK dryer principle of induction heating (a) rotating drum at 15-20 rpm (b) single-turn tertiary load 8000 A at 5 V/m (c) secondary bus bar and (d) silicon iron transformer core (b) cross section of ROTEK dryer (1) air extraction duct (2) feed hopper ... 

Hopper IE, Broach JR, Rowe LB. Regulation of the galactose pathway in Sacchar-omyces cerevisiae induction of uridyl transferase mRNA and dependency on GAL4 gene function. Proc Natl Acad Sci USA 1978 75 2878-2882. 

Extruder Barrel n (extruder cylinder) A thick-walled, cylindrical steel tube, lined with a special hard alloy to resist wear that forms the housing for the extruder screw and contains, between itself and the screw, the plastic material as it is conveyed from feed hopper to die. Barrels are usually surrounded by heating and cooling media, such as electrical heater bands, cast-in-aluminum calrods and tubing for coolant, induction heaters, or, rarely, by a compartmented jacket for the... 

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