Liquid outlet velocity

Oil in gas droplet size Oil in water droplet size Water in oil droplet size Slug volume (water slug) Inlet nozzle momentum Momentum (gas outlet) Liquid outlet velocity Operating pressure... 

This maximum velocity of a compressible fluid in a pipe is limited by the velocity of propagation of a pressure wave that travels at the speed of sound in the fluid [3]. This speed of sound is specific for each individual gas or vapor or liquid and is a function of the ratio of specific heats of the fluid. The pressure reduces and the velocity increases as the fluid flows downstream through the pipe, wdth the maximum velocity occurring at the downstream end of the pipe. WTien, or if, the pressure drop is great enough, the discharge or exit or outlet velocity will reach the velocity of sound for that fluid. 

The height of the draft-tube also Influences the flow characteristics in the ALR. Fig.9 and Fig. 10 show that the liquid superficial velocity increases with increasing the hei t (H) of the draft-tube, while the liquid superficial velocity remains approximately unchanged when H exceeds 0.51m. With a hi er position of draft-tube, the flow area at the outlet of the draft-tube becomes larger, so the liquid velocity at the outlet decreases. 

In design of separating chambers, static vessels or continuous-flow tanks may be used. Care must be taken to protect the flow from turbulence, which could cause back mixing of partially separated fluids or which could carry unseparated liquids rapidly to the separated-liquid outlet. Vertical baffles to protect rising bubbles from flow currents are sometimes employed. Unseparated fluids should be distributed to the separating region as uniformly and with as little velocity as possible. When the bubble rise velocity is quite low, shallow tanks or flow channels should be used to minimize the residence time required. 

In liquid chromatography, the compressibility of the mobile phase is small, and in practice it is often negligible, unless high accuracy measurements are made for a specific purpose [24]. Under steady-state conditions, the equation of continuity of the mobile phase can be integrated to give u = uq = constant, where mq is the outlet velocity. When the viscosity of the sample and that of the mobile phase do not differ significantly, Eq. 5.86 can be integrated, and the total pressure drop can be calculated as... 

In these equations, CfJ and Cfj are the concentrations of component i at the outlet and the inlet of column /, respectively. Qj is the actual volumetric flow rate of mobile phase through column j. It is related to the liquid phase velocity, Uj, by Qj = eAuj, where A is the column cross-section area, which is assumed, without loss of generality, to be the same for all the columns including the feed and drawoff columns. 

A gas-liquid mixture of Freon 12 of 90 percent quality at a pressure of 200 psia is passed through a throttling valve. Flow is steady, and the exit pressure is 20 psia. The outlet velocity is very small. What is the outlet temperature ... 

Consider a chromatographic column. When the mobile phase is a liquid, the carrier velocity (v) is not a strong function of the axial position in the column because, in general, liquids are not very compressible. Gases are, however, quite compressible and so a correction is applied to the adjusted volume Fj. to obtain the net volume Fp. It can be shown that the average carrier velocity in the column V is related to the outlet velocity Vo by a correction factor j, given by... 

Vortex breaker Located in draw-off nozzle sumps, or on the liquid outlet of the bottom of a vessel. Not required for low nozzle outlet velocities. 

In the above relations, Re is the Reynolds number, mo is the liquid flow velocity at the nozzle outlet, d i is the inner diameter of the nozzle, vl is the kinematic viscosity of liquid, Fr is the Froude number, g is the acceleration due to gravity, is the density of liquid. We is the Weber number, a is the surface tension of liquid, is the velocity ratio defined subsequently, and 2g is the gas flow rate. 

Liquid outlet nozzles are generally designed based on the liquid superficial velocity of 1 m/sec. 

Volute casings take the form of a spiral increasing uniformly in cross-sectional area as the outlet is approached. The volute efficiently converts the velocity energy imparted to the liquid by the impeller into pressure energy. 

In a submerged-tube FC evaporator, all heat is imparted as sensible heat, resulting in a temperature rise of the circulating hquor that reduces the overall temperature difference available for heat transfer. Temperature rise, tube proportions, tube velocity, and head requirements on the circulating pump all influence the selec tion of circulation rate. Head requirements are frequently difficult to estimate since they consist not only of the usual friction, entrance and contraction, and elevation losses when the return to the flash chamber is above the liquid level but also of increased friction losses due to flashing in the return line and vortex losses in the flash chamber. Circulation is sometimes limited by vapor in the pump suction hne. This may be drawn in as a result of inadequate vapor-liquid separation or may come from vortices near the pump suction connection to the body or may be formed in the line itself by short circuiting from heater outlet to pump inlet of liquor that has not flashed completely to equilibrium at the pressure in the vapor head. 

Limestone is pulverized to 80 to 90 percent through 200 mesh. Shiny concentrations of 5 to 40% have been checked in pilot plants. Liquid to gas ratios are 0.2 to 0.3 gaLMSCF. Flue gas enters at 149°C (300°F) at a velocity of 2.44 m/s (8 ft/s). Utilization of 80 percent of the solid reagent may be approached. Flow is in parallel downward. Residence times are 10 to 12 s. At the outlet the particles are made just diy enough to keep from sticking to the wall, and the gas is within 11 to 28°C (20 to 50°F) of saturation. The fine powder is recovered with fabric filters. 

Horizontal Blowdown Drum/Catch Tank This type of drum, shown in Fig. 26-16, combines both the vapor-liquid separation and holdup functions in one vessel. Horizontal drums are commonly used where space is plentiful, such as in petroleum refineries and petrochemical plants. The two-phase mixture usually enters at one end and the vapor exits at the other end. For two-phase streams with very high vapor flow rates, inlets may be provided at each end, with the vapor outlet at the center of the drum, thus minimizing vapor velocities at the inlet and aiding vapor-hquid separation. 

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