Nozzle hole shapes

Keywords Discrete polydisperse spray Electric droplet charging Extension nozzle Ink-jet printing Monodisperse droplet stream Monodisperse spray Multihole orifice Modulated jet excitation Nozzle hole shapes Rapid prototyping Rayleigh-type jet break-up Solder ball production... 

The 300-psig steam next passes through the steam nozzle. This is an ordinary nozzle. It screws into a hole in the wall, which separates the steam chest from the turbine case. The nozzle is shaped to efficiently convert the pressure of the 300 psig to steam velocity. The pressure of the steam, as soon as it escapes from the steam nozzle, is already the same as the exhaust steam pressure (100 psig). 

As single-hole nozzle plates, circular orifice disks, typically 200 pm thick, with the nozzle hole in the center, are equally suitable as thin metal sheets, as used, e.g., for spatial filtering in optical setups. Thicker disks are best suitable as orifice plates if the hole exhibits a tapered (inlet) region on one side and has its nominal diameter only on a short part of the plate thickness. This feature ensures low flow resistance and good directional stability of the jet. Figure 26.9 shows typical shapes of nozzle cross section profiles [41]. 

Fig. 26.9 Left Shape of a typical nozzle hole for spinnerets with tapered inlet region. Right. Nozzle hole with curved shape, as typically obtained by laser drilling. Simple cylindrical holes in thin metal sheets are also suitable for producing liquid jets of good quality [41] (Reproduced from [41]. With kind permission. Copyright Wiley-VCH Verlag GmbH and Co. KGaA)...

Utilizing a forced-draft fan, the burner has a gas head arranged to mix the fuel and air in a blast tube which controls the stability and shape of the flame. Gas exits from nozzles or holes in the head and is mixed partly in the high-velocity air stream and partly allowed to exit into an area downstream of a bluff body. Behind the bluff body, a relatively quiescent zone forms which provides a means for flame stability. Many configurations exist, but the most... 

Nuclear Reactor with a Hole in the Head On March 6,2002, personnel repairing one of the five cracked control rod drive mechanism (CRDM) nozzles at Davis-Besse Nuclear Plant, Oak Harbor, Ohio, discovered extensive damage to the reactor vessel head. The reactor vessel head is a dome-shaped structure made from carbon steel housing the reactor core. The reactor vessel head is placed such that it can be removed when the reactor is shut down to allow spent nuclear fuel to be replaced with fresh fuel. The CRDM nozzles connect motors mounted on a platform above the reactor vessel head to control rods inside the reactor vessel. Reactor operators withdraw control rods from the reactor core to start the operation of the plant and insert the control rods to shut down the operation of the reactor. 

In the present section, we restrict ourselves to the version of droplet generators working with (mostly metal) nozzle plates carrying the orifice hole(s). The design of the nozzle plate concerns both the diameter and the shape of the... 

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