Tubes annulus

Hydrostatic The tubing annulus is filled with water to ensure its... 

Developing Turbulent Flov/ in the Entrance Region 4/6 Turbulent Flo. v in N oncircular Tubes 476 Flow through Tube Annulus 477 Heat Transler Enhancement 477... 

For fully developed turbulent flow, the inner and outer convection coefficients are approximately equal to each other, and the tube annulus can be treated as a noncircular duct with a hydrauLc diameter of - 77, . The Nusselt num-... 

Several examples of the use of MFI-based membranes are described in a patent of Haag et al. [ 86]. These authors developed a reactor consisting of an inner porous alumina tube, carrying on its interior wall a 12 im ZSM-5 membrane. The alumina tube was mounted in an outer steel tube and the inner-tube annulus had a width of about 0.5 cm, both tubes were separately fitted... 

Nusselt number for fully developed laminar flow in a circular tube annulus with one surface insulated ana the other at a con-stant temperature... 

The PCP is not a complete panacea for solids production from wells. Above 25% water cut, pumping problems because of sanding-in above the pump discharge have been observed (114). The pump suction intake can also be blocked, but this is a less common occurrence. Various solutions to the problem have been considered, including loading the annulus with produced oil (at the expense of increased bottom-hole pressure and some productivity impairment), cyclic loading of the tubing annulus, or reduction of hydraulic radius between pump rods and pro-... 

Figure 7. Correlation for proppant friction correction factor—5.5 in. csg, 1.9-in. tubing annulus. (Reproduced with permission from reference 29. Copyright 1983 Society of Petroleum Engineers.)...

Common methods of introducing catalyst materials into the MR. Catalyst is packed inside the tubular membrane module (a) in the shell side or (b) in the tube (annulus) side, or (c) catalyst is dispersed along the membrane during in-situ preparation. 

Sensors on the tree allow the control module to transmit data such as tubing head pressure, tubing head temperature, annulus pressure and production choke setting. Data from the downhole gauge is also received by the control module. With current subsea systems more and more data is being recorded and transmitted to the host facility. This allows operations staff to continuously monitor the performance of the subsea system. 

Fanning friction factor /i for inner wall and / 2 for outer wall of annulus /l for ideal tube bank sldn friction drag coefficient Dimensionless Dimensionless... 

V Radius cylindrical and spherical coordinate distance from midplane to a point in a body i i for inner wall of annulus Vo for outer wall of annulus for inside radius of tube for distance from midplane or center of a body to the exterior surface of the body m ft... 

When pumping down the draft tube, flow normally makes a more troublefree velocity change to a flow going up the annulus. Since the area of the draft tube is markedly less than the area of the annulus, pumping up the draft tube requires less flow to suspend sohds of a given settling velocity than does pumping down the draft tube. 

Nozu, S., Honda, H. and Nishida, S., Condensation ofZeotropic CFC114-CFC113 Refrigerant Mixture in the Annulus of a Double-Tube Coil with an Enhanced Inner Tube, Experimental Thermal and Fluid Science, Vol. 11, pp364-371, 1995. 

Zauner and Jones (2000a) describe an experimental set-up for determination of precipitation kinetics, as shown in Figure 6.19. Briefly, the jacket glass reactor (1) (300 ml, d = 65 mm) is equipped with a polyethylene draft tube and four baffles. The contents are stirred using a three-blade marine-type propeller (5) with motor (Haake), which pumps the suspension upwards in the annulus and downwards inside the draft tube. Measured power inputs ranged from 3.3 X 10- to 1.686 W/kg. 

The product withdrawal pipe is located in the annulus halfway up the draft tube where the vector of the circulation velocity of the suspension and that of the withdrawal velocity of the product point in the same direction. Using this arrangement ensures low particle classification effects. Furthermore, the feed tubes and withdrawal tube can be exactly positioned in the reactor and scaled... 

With a draft tube inserted in a tank, no sidewall baffles are required, and, the flow into the axial impeller mounted inside the tube is flooded to give a uniform and high flow pattern into the inlet to the impeller. The upflow in the annulus around the tube has sufficient velocity to keep particles in suspension, if necessary. 

Dj = outside diameter of inner tube, ft Dj = inside diameter of outer pipe, ft r[, = hydraulic radius, ft = (radius of a pipe equivalent to the annulus cross-section)... 

This unit consists of two pipes or tubes, the smaller centered inside the larger as shown in Figure 10-92. One fluid flows in the annulus between the tubes the other flows inside the smaller tube. The heat transfer surface is considered as the outside surface of the inner pipe. The fluid film coefficient for the fluid inside the inner tube is determined the same as for any straight tube using Figures 10-46-10-52 or by the applicable relations correcting to the O.D. of the inner tube. For the fluid in the annulus, the same relations apply (Equation 10-47), except that the diameter, D, must be the equivalent diameter, D,.. The value of h obtained is applicable directly to the point desired — that is, the outer surface of the inner tube. ... 

Dz = Inside Diameter of the Outer Tube (A). Annulus Area for Flow is Between Tubes (A) and Heat Transfer Coefficients used are hj at Inside Surface of Tube (B) ho at Outside Surface of Tube (B)... 

Figure 10-92. Double-pipe tube arrangement showing annulus area.

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