Edge nozzles

Edge nozzles are used both as central nozzles with one or more injection points, and as manifold nozzles, thus making it possible to design multi-cavity moulds with a reduced number of nozzles. Edge nozzles have enabled the economic problem underlying moulding of small products to be resolved, in much the same way as multi-tip nozzles did. 

Because of the relatively low gate temperature, good conditions were created for the injection of thermally-stable amorphous plastics with an injection temperature of less than 300 °C, and for injection of slow-setting crystalline plastics (like PE or PP). This type of nozzle is most commonly used to manufacture packaging featuring a short cycle time and where colour changes are infrequent. In both designs the melt flows via semicircular channels located in the nozzle face. 

When installing a central nozzle, the relatively large force ejecting the nozzle from the mould arising from the injection pressure should be considered. 

Tip nozzles. In recent years, tip nozzles for edge injection have also been designed. Because the tip is introduced into the gate, the length of the gate ceases to be a critical value, the cold plug in the nozzle is eliminated, and the mould wall has been thickened to 2-3 mm. 

The halves of the chamber are clamped by keys. This nozzle is also suitable for processing PA, PBT and PC with glass fibre. 

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Procedure A sharp-edged nozzle is positioned in the duct, facing into the moving gas stream, and a gas sample is extracted isokinetically (see later) for a measured period of time. To allow for nonuniformity of particulate concentration in the duct, samples are taken at preselected positions in the duct cross-section. The particulate concentration is calculated from the weighed particulate mass and the gas sample volume. Figure 13.39 shows the measuring arrangement. 

Pressure pulsations caused by sharp-edged nozzle entrances... 

TB-1-25 blower blew the air through the material. The regulating valve in the blower s inlet maintained the air consumption. The amount of the consumed air was measured by a calibrated round-edged nozzle (length-diameter ratio 1/d = 4.3) which refers to the consumption coefficient ji=0.97. The nozzle was placed in the chamber for gas velocity levelling. The air pressure near the nozzle was measured by a liquid U-shaped manometer. The amount of air passing through the layer was calculated by ... 

Several relations for the sheet thickness in terms of flow parameters are provided in Table 33.1. Schmith et al. [45] argued that is about 0.7 based on the comparison with the discharge coefficient of a sharp-edge nozzle for a single fluid with LID = 4, which is 0.78. If the cone angle is 0, then the axial velocity Uo at the nozzle exit is... 

Figure 4.47 Principles for location of edge nozzles depending on shape of moulded item...

Figure 4.48 Edge nozzles with insulation chamber...

Figure 4.49 Application of open two-point edge nozzles in a 16-cavity mould for the production of aerosol caps [16] - theologically balanced mould...

Nozzles with the power lead running in from the side (see Figure 4.94) are set between the manifold and the cavity plate in the axis of the channel (not adjacent). These nozzles may be in the form of a torpedo, a mnlti-tip nozzle or an edge nozzle. 

In a concentric-tube nebulizer, the sample solution is drawn through the inner capillary by the vacuum created when the argon gas stream flows over the end (nozzle) at high linear velocity. As the solution is drawn out, the edges of the liquid forming a film over the end of the inner capillary are blown away as a spray of droplets and solvent vapor. This aerosol may pass through spray and desolvation chambers before reaching the plasma flame. 

Other forms of carbon-carbon composites have been or are being developed for space shutde leading edges, nuclear fuel containers for sateUites, aircraft engine adjustable exhaust nozzles, and the main stmcture for the proposed National Aerospace plane (34). For reusable appHcations, a siHcon carbide [409-21 -2] based coating is added to retard oxidation (35,36), with a boron [7440-42-8] h Lsed sublayer to seal any cracks that may form in the coating. 

Gas-Solid Mixtures Carlson, Frazier, and Engdahl [Trans. Am. Soc. Mech. Eng., 70, 65-79 (1948)] describe the use of a flow nozzle and a square-edged orifice in series for the measurement of both the gas rate and the solids rate in the flow of a finely divided solid-in-gas mixture. The nozzle differential is sensitive to the flow of both phases, whereas the orifice differential is not influenced by the sohds flow. 

FIG. 18-132 Sectional view of the Cuno Flo-Klean backwashing edge filter. Fluid pumped through the nozzle loosens solids from the filter surface and clears the filtering area. The pump draws filtered fluid from the filter discharge and returns it to the system through the nozzle. Thus, there is no loss of backwash fluid. (Cuno Division, AMF, Inc.)... 

Special propulsion also requires relevant calculations and distribution of the anodes. For Kort nozzles, the total surface area of the mdder is determined and a basic protection current density of 25 mAm" imposed. The anodes are attached on the external surface at a spacing of 0.1 r to 0.25 r at the region of greatest diameter. Internally the anodes are fixed to the strengthening stmts. With Voith-Schneider propellers, the anodes are arranged around the edge of the base of the propeller. 

Inspeetion during shutdown showed evidenee of blade erosion and pits loeated on the leading edge and the eoneave side of the trailing edge. For expanders operating at a eonstant speed, the veloeity diagram depends on the absolute speed of the mass earrier. The absolute speed, Cj, may be ealeulated from the nozzle formula ... 

Baturin " studied air jets supplied from rectangular nozzles at some angle to the plane with an edge of the nozzle coincident with the plane. The results of his studies indicate that the critical value of the angle of the jet supply direction to the plane is 45°. It was also shown that the jet supplied through a rectangular outlet with a nozzle kxated at some distance from the plane does not attach to the surface. 

Avoid having any sharp edges at the inlet opening or inside the nozzle ... 

Edges of tubesheet holes Pressure gauge and thermowells on flange nozzles Min. bolt diameter... 

Figure 3-1 (page 19) shows where an end-of-line deflagration flame arrester should he located. It preferably should be installed on a nozzle that is near the outer edge of the tank/vessel roof for ease of accessibility for maintenance and removal. 

Location of first nozzles 8-12 in (20-30 cm) from the edge of the slot in the branch arm... 

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