Variable nozzle

Variable nozzles produce a series of jets of gas entering the rotor, and these impulses add up to form a frequency equal to the blade-passing frequency the number of revolutions per second multiplied by the number of nozzle vanes, which is of the order of thousands of cycles per second. Frequently the rotor will resonate at this frequency, and if it does, it will be fatigued and crack and break up thus these frequencies must be avoided, and the manufac turer should be asked to supply information to the customer on this subject. 

Process-flow control and buffer-gas control have been discussed under Variable Nozzles and Buffer-Gas System respectively. Speed is usually self-controlled by a matching speed-sensitive load such as a compressor or a pump. If the load is an induction or svn-chronous generator feeding into a stable ac system, the system frequency fixes the speed. Otherwise, the speed can be controlled by a conventional governor. 

Turboexpanders require variable flow control nozzles capable of withstanding the total pressure and acting as the flow control for the main gas stream through the plant. The variable nozzles are matched... 

The expander is now ready to be put into operation. Open the compressor inlet valve and expander discharge valve simultaneously. Then open the compressor discharge valve. Make sure the variable nozzles are in the closed position. Push the start button on the control panel to open the inlet shutdown valve. 

Interchangeable gear cylinders are available with variable nozzle L/D ratios by counterboring from the inside of the rollers to reduce the die length or by using replaceable nozzle inserts to increase the die length. 

D.W. Gill, G. Heimel, P.L. Herzog "A variable nozzle concept for high speed DI diesel engines." IMechE Seminar on Diesel Fuel Injection Systems, 28-29 Sept. 1995. 

Use VNT variable nozzle turbine inlet geometry to improve performance across the desired flow range. 

Completed the analysis, design, and fabrication of the turboeompressor with a mixed flow compressor and VNT variable nozzle turbine. 

Complete testing of the turbocompressor VNT variable nozzle turbine. 

Figure 1. Honeywell Fuel Cell Turbocompressor with Mixed Flow Compressor and VNT" Variable Nozzle Turbine...

Hybrid aircraft can perform both functions to a considerable extent and appear to be the way of the future in the development of new aircraft systems. The existing hybrid craft are used solely by the military. The V-22 Osprey is a tilt-wing system developed by Bell Boeing, and the Harrier Jump Jet is a British creation that uses a variable nozzle system to redirect power. 

It is an example of a well-designed plant for introducing chlorinated water to the 50% caustic/dilution water manifold. The operating vacuum is developed by an aspirator-type injector. As soon as the operating vacuum is developed, the chlorine gas enters the chlorinator through the combination valve. This valve closes if the vacuum decreases to an insufficient level or vents to the atmosphere if over-pressure occurs. It also maintains the suitable vacuum-level ahead of the V-notch variable nozzle. 

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