Nozzle losses

The reaetion turbine avoids this U-turn and its effieieney penalty. In the reaetion turbine half of the pressure energy is spent aeross the rotor, so there must be a seal around the rotor. With the rotor inlet at its periphery, the diseharge from the rotor may now be ehosen at a redueed diameter radial, or quasi axial, shaft-eoneentrie position. Sinee the diseharge is obviously smaller in diameter, the rotor seal will also be smaller in diameter beeause it only needs to suiTound the diseharge portion of the rotor. As a eonsequenee, seal loss is redueed and shaft thrust deereases as well. Likewise, the diseharge or seeondary nozzle losses are redueed beeause the gas exits at lower veloeity. 

Damaged or partially plugged Feed Nozzles Loss of the Shed decks Feed leaking through Bottoms exchangers or Feed Diversion Valve... 

The vapor-line riser pressure drop, including the vapor outlet nozzle loss. 

Each primary safety valve inlet line is designed to pass 630,000 Ibm/hr with a maximum pressure drop of 50 psi from the pressurizer to the safety valve. This pressure drop of 50 psi is for piping and nozzle losses. 

The 0.34 is a nozzle-loss coefficient. The 20 ft/s is the velocity of the kerosene in the 3-inch restriction. The 28 factor converts AP from inches of water pressure drop to psi. 

Better yet, just measure the pressure at Pi and forget about the corrections for nozzle losses. On the other hand, the fluid flowing from a nozzle into a vessel will usually gain in pressure (pressure recovery). 

Aluminum-containing propellants deflver less than the calculated impulse because of two-phase flow losses in the nozzle caused by aluminum oxide particles. Combustion of the aluminum must occur in the residence time in the chamber to meet impulse expectations. As the residence time increases, the unbumed metal decreases, and the specific impulse increases. The soHd reaction products also show a velocity lag during nozzle expansion, and may fail to attain thermal equiUbrium with the gas exhaust. An overall efficiency loss of 5 to 8% from theoretical may result from these phenomena. However, these losses are more than offset by the increase in energy produced by metal oxidation (85—87). 

Another option available with rotary vacuum dmm filters is fiiU enclosure. This enables operation under nitrogen or other atmospheres, for reasons such as safety, prevention of vapor loss, etc. Enclosure may also be used to prevent contamination of the material being filtered or to confine the spray from washing nozzles. The rotary dmm filter also can be enclosed in a pressure vessel and operated under pressure. 

Permanent pressure loss across a subsonic flow nozzle is approximated by... 

See Benedict, loc. cit., for a general equation for pressure loss for nozzles installed in pipes or with plenum inlets. Nozzles show higher loss than venturis. Permanent pressure loss for laminar flow depends on the Reynolds number in addition to p. For details, see Alvi, Sri-dharan, and Lakshamana Rao, J. Fluids Eng., 100, 299-307 (1978). 

Impingement Baffle The tube bundle is customarily protected against impingement by the incoming fluid at the shell inlet nozzle wmen the shell-side fluid is at a high velocity, is condensing, or is a two-phase fluid. Minimum entrance area about the nozzle is generally equal to the inlet nozzle area. Exit nozzles also require adequate area between the tubes and the nozzles. A full bundle without any provision for shell inlet nozzle area can increase the velocity of the inlet fluid by as much as 300 percent with a consequent loss in pressure. 

Sufficient distance should be provided from the outer nozzles to keep spray from being carried over the sides of the basin. If it is not possible to provide 7.6 to 10.7 m (25 to 35 ft) of space, the pond should be enclosed with a louver fence, equal in hei t to the maximum height of the spray, to minimize drift loss. Also, during cold-weather periods, fogging can occur from the spray pond, so that consideration should be given to possible hazards to roadways or buildings in the immediate vicinity. 

In calculating the impact point of spray, one should recognize that the spray angle closes in as the spray moves away from the nozzle. This is caused by loss of momentum of the spray to the gas. 

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.)... 

Minimize moisture hiiildiip losses. Avoid formulations which exhibit adhesive characteristics with respect to process walls. Maintain spray nozzles to avoid caking and nozzle drip. Avoid spray entrainment in process air streams, and spraying process walls. 

If it becomes necessary to increase the stack-gas exit velocity to avoid downwash, it may be necessary to remodel the stack exit. A venturi-nozzle design has been found to be the most effective. This design also keeps pressure losses to a minimum. 

Ideal (Frictionless) Flow in Nozzles The flow path in well-formed nozzles follows smoothly along the nozzle contour without separating from the wall. The effects of small imperfections and small frictional losses are accounted for by correcting the ideal nozzle flow by an empirically determined coefficient of mscharge. The acceleration of a fluid initially at rest to flowing conditions in an ideal nozzle is given by ... 

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