Delivery nozzle

Relative Angle between Gas Nozzle and Metal Delivery Nozzle (°) 7 15 (Vertical) 90 (Horizontal)... 

Delivery Nozzle Material Ceramics/Refractory Steels... 

Scale-up of gas atomizers is difficult and it requires the use of higher gas-to-melt mass flow rate ratio to maintain the same droplet size. The scale-up may also cause some complex phenomena to occur, such as the disappearance of the prefilming effect in close-coupled atomizers, the generation of turbulence in melt flow within delivery nozzle, and change in atomization mechanisms. 

A limited number of empirical correlations have been developed for metal droplet sizes generated by water atomization, as listed in Table 4.18. In these correlations p is a system-specific constant, is the atomizing angle, i.e., angle between water nozzle axis and metal delivery nozzle axis, A is a proportional constant specific to atomizer type, melt type and melt temperature, n is a parameter depending on atomizer type, APw is the water pressure, Uw is the water velocity, and mw is the mass flow rate of water. 

The mass flow rate of a liquid metal through a delivery nozzle orifice may be calculated with the following equation 605 ... 

Once the extraction is complete, the dead-ended valve is repositioned to allow flow. Subsequently, pressure and density are rapidly reduced to prevent significant losses of the supercritical fluid and the extraction effluent is transferred for collection. With a non-restricted transfer, the flow of supercritical fluid effluent is rapid. This rapid depressurization was made possible by the invention of a delivery nozzle which would ensure collection of the extracted solutes without losses. It consists of a small inverted polyethylene delivery funnel, a few common stainless steel fittings and a spring. No loss of the extracted solutes and modifier has been observed with the use of this nozzle. 

With this system, two extract delivery lines are required, one for each of the vessels as well as two delivery nozzles. The advantages of this mechanism are its simplicity, ease of operation, and its capacity. The mechanism is also compatible with the method-chaining program in the SUPREX. Since the extraction vessels are treated as pairs,when the program asks for a count number on the columns, an entry of six, which is the maximum allowable, will result in twelve extractions, i.e. 2N. An entry of four will result in eight extractions, etc. However, because at each actuation of the solenoids, a pair of columns is selected, this mechanism does not allow room for independent method use between the extraction vessel pairs. 

With the 12-vessel extractor, the 1/8" valve receives the extraction effluent from the vessels in tandem column selectors 1 and 2 (TCS-1 and TCS-2) into two separate ports 1 and 4 as shown in Figure 7. During the static mode, the counter-current valves, i.e. modifier pump valves (MP-3 and MP-4) are closed. Pressure build-up for static extraction then follows. Valves MP-3 and MP-4 are mounted close to the ports so that no accumulation of extract occurs. The valves are connected via a stainless steel tee (T2), to the modifier pump which is also used for flushing the lines after the extractions have been conducted. In the dynamic mode, extract flows from the unblocked ports of 1 and 4 to ports 5 and 6 then through to the delivery nozzles. 

Delivery of Extract Delivery Nozzle. Delivery of the extraction effluent is conducted via the six port static/dynamic valve while in the dynamic mode. Generally, extractions are conducted at a high density in the static mode. Once the extraction is complete, the valve is re-positioned into a dynamic evacuation, pressure or density is reduced rapidly to prevent significant losses of the supercritical fluid and the extraction effluent is transferred for collection. The extract leaves through the heated static/dynamic valve to the heated lines then to the delivery nozzle(s). Figure 8 shows a diagram of the delivery nozzle and its components. 

Figure 8. Extraction Effluent Delivery Nozzle Design with Component Parts.

These images, obtained in <10 min, led to a method for rapidly assessing the performance of spray delivery nozzles. Spatial distribution of spray, as well as some quantitative information about distribution uniformity, was quickly obtained. This test replaced a previous method where spray was deposited onto a 96-well plate (shown on the right half of the figure). The previous method required individual measurements at each of the 96 wells, took several hours to complete and resulted in much poorer spatial resolution. The NIR spectral imaging method provided a much quicker test. 

Filtration Assembly Connect the Filter Stick with an air pressure inlet tube and delivery nozzle and ground-glass joint to fit a 25- x 170-mm test tube as shown in Fig. 10. If a stainless steel Filter Stick is used, make the connection to the test tube by means of a cork. 

Fig. 3 Spotting tools for non-contact printing a Bubble ink-jet A heating coil locally heats the loaded sample, resulting in a changed viscosity and expansion of fluids. The generated droplet can be easily expelled from delivery nozzles, b Microsolenoid A microsolenoid valve, fitted with the ink-jet nozzle is actuated by an electric pulse transiently opening the channel and dispenses a defined volume of the pressurized sample, c Piezo ink-jet A piezoelectric transducer that is fitted around a flexible capillary confers the piezoelectric effect based on deformation of a ceramic crystal by an electric pulse. An electric pulse to the transducer generates a transient pressure wave inside the capillary, resulting in expulsion of a small volume of sample...

Fig. 5.3. Apparatus used in the iodometric assay. G inert gas supply PS presaturator P pipettor M magnetic stirrer SD solvent delivery nozzle FR flow regulator D gas distributor CT connecting tube V vial S stopper with capillary opening SV side valve ST screw-top stopper holder N syringe needle. (Gebicki and Guide, 1989.)...

Fluid is added using a plastic wash bottle with a single delivery nozzle, which is easy and inexpensive. Here the wells are filled individually in rapid succession and then emptied by inverting the plate and flicking the contents into a sink or suitable container filled with disinfectant. This process is repeated at least three times. Wells filled with washing solution may also be left for about 30 s before emptying. 

Wash Bottles Plus Multiple Delivery Nozzles... 

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