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And pressure drop

Inlet pressure and pressure drop (gas-phase reactions)... [Pg.326]

Liquid viscosity is one of the most difficult properties to calculate with accuracy, yet it has an important role in the calculation of heat transfer coefficients and pressure drop. No single method is satisfactory for all temperature and viscosity ranges. We will distinguish three cases for pure hydrocarbons and petroleum fractions ... [Pg.126]

Venturi scmbbers can be operated at 2.5 kPa (19 mm Hg) to coUect many particles coarser than 1 p.m efficiently. Smaller particles often require a pressure drop of 7.5—10 kPa (56—75 mm Hg). When most of the particulates are smaller than 0.5 p.m and are hydrophobic, venturis have been operated at pressure drops from 25 to 32.5 kPa (187—244 mm Hg). Water injection rate is typicaUy 0.67—1.4 m of Hquid per 1000 m of gas, although rates as high as 2.7 are used. Increasing water rates improves coUection efficiency. Many venturis contain louvers to vary throat cross section and pressure drop with changes in system gas flow. Venturi scmbbers can be made in various shapes with reasonably similar characteristics. Any device that causes contact of Hquid and gas at high velocity and pressure drop across an accelerating orifice wiU act much like a venturi scmbber. A flooded-disk scmbber in which the annular orifice created by the disc is equivalent to a venturi throat has been described (296). An irrigated packed fiber bed with performance similar to a... [Pg.410]

The shear stress is hnear with radius. This result is quite general, applying to any axisymmetric fuUy developed flow, laminar or turbulent. If the relationship between the shear stress and the velocity gradient is known, equation 50 can be used to obtain the relationship between velocity and pressure drop. Thus, for laminar flow of a Newtonian fluid, one obtains ... [Pg.108]

Eurther research on convective transport under low Reynolds number, quasicontinuum conditions is needed before the optimal design of such a micro heat exchanger is possible. The cooling heat exchanger is usually thermally linked to a relatively massive substrate. The effects of this linkage need to be explored and accurate methods of predicting the heat-transfer and pressure-drop performance need to be developed. [Pg.495]

When the operation of the hoUow-ftber membrane is to be reversed, and permeation from the bore to outer 2one is required, circumferential stress and pressure drop along the fiber capiUary (bore) must be considered in the design of the fiber unit. The circumferential stress, S is expressed as... [Pg.147]

Although it has been common practice to specify the pressure loss in ordinary valves in terms of either equivalent length of straight pipe of the same size or velocity head loss, it is becoming more common to specify flow rate and pressure drop characteristics in the same terms as has been the practice for valves designed specifically for control service, namely, in terms of the valve coefficient, C. The flow coefficient of a valve is defined as the volume of Hquid at a specified density that flows through the fully opened valve with a unit pressure drop, eg, = 1 when 3.79 L/min (1 gal /min) pass through the valve... [Pg.57]

Fig. 24. Generalized method using log scales for estimating packed column flooding and pressure drop, AP, in kPa/m g = gravitational constant, 9.81 m/s t = kinematic viscosity in mm /s (= cSt) E, G have units of kg/(m s) are in kg/m and the packing factor, F, in can be found in... Fig. 24. Generalized method using log scales for estimating packed column flooding and pressure drop, AP, in kPa/m g = gravitational constant, 9.81 m/s t = kinematic viscosity in mm /s (= cSt) E, G have units of kg/(m s) are in kg/m and the packing factor, F, in can be found in...
Catalyst contamination from sources such as turbine lubricant and boiler feed water additives is usuaUy much more severe than deactivation by sulfur compounds in the turbine exhaust. Catalyst formulation can be adjusted to improve poison tolerance, but no catalyst is immune to a contaminant that coats its surface and prevents access of CO to the active sites. Between 1986 and 1990 over 25 commercial CO oxidation catalyst systems operated on gas turbine cogeneration systems, meeting both CO conversion (40 to 90%) and pressure drop requirements. [Pg.512]

The hydrauhc diameter method does not work well for laminar flow because the shape affects the flow resistance in a way that cannot be expressed as a function only of the ratio of cross-sectional area to wetted perimeter. For some shapes, the Navier-Stokes equations have been integrated to yield relations between flow rate and pressure drop. These relations may be expressed in terms of equivalent diameters Dg defined to make the relations reduce to the second form of the Hagen-Poiseulle equation, Eq. (6-36) that is, Dg (l2SQ[LL/ KAPy. Equivalent diameters are not the same as hydraulie diameters. Equivalent diameters yield the correct relation between flow rate and pressure drop when substituted into Eq. (6-36), but not Eq. (6-35) because V Q/(tiDe/4). Equivalent diameter Dg is not to be used in the friction factor and Reynolds number ... [Pg.638]

Throughput is therefore proportional to mass flow rate. For a given mass now rate, throughput is independent of pressure. The relation between throughput and pressure drop Ap =pi—po across a flow element is written in terms of the conductance C. Resistance is the reciprocal of conduc tance. Conductance has dimensions of volume per time. [Pg.641]

Porous Media Packed beds of granular solids are one type of the general class referred to as porous media, which include geological formations such as petroleum reservoirs and aquifers, manufactured materials such as sintered metals and porous catalysts, burning coal or char particles, and textile fabrics, to name a few. Pressure drop for incompressible flow across a porous medium has the same quahtative behavior as that given by Leva s correlation in the preceding. At low Reynolds numbers, viscous forces dominate and pressure drop is proportional to fluid viscosity and superficial velocity, and at high Reynolds numbers, pressure drop is proportional to fluid density and to the square of superficial velocity. [Pg.665]

For the larger sizes in high-pressure service, the fixed-ball type with O-ring seat seals requires less operating effort. However, these require two different plastic materi s with resistance to the fluid and its temperature. Like plug cocks, ball valves may be either restricted-port or full-port, but the ports are always round and pressure drop is low. [Pg.969]

The design chosen in step 5 is evaluated, or rated, as to its ability to meet the process specifications with respect to both heat transfer and pressure drop. [Pg.1034]

Typical overall coefficients to start a rough sizing are as below. Use these in conjunction with the NTU calculated for the process. The closer the NTU matches the plate (say between 2.0 and 3.0), the higher the range of listed coefficients can be used. The narrower (smaller) the depth of corrugation, the higher the coefficient (and pressure drop), but also the lower the abdity to carry through any particulate. [Pg.1084]

The channel spacings can be different on each side to match the flow rates and pressure drops of the process design. The spacer studs are also adjusted in their pitch to match the fluid charac teristics. [Pg.1085]

Cascade coolers are a series of standard pipes, usually manifolded in parallel, and connected in series by vertically or horizontally oriented U-bends. Process fluid flows inside the pipe entering at the bottom and water trickles from the top downward over the external pipe surface. The water is collected from a trough under the pipe sections, cooled, and recirculated over the pipe sections. The pipe material can be any of the metallic and also glass, impeiMous graphite, and ceramics. The tubeside coefficient and pressure drop is as in any circular duct. The water coefficient (with Re number less than 2100) is calculated from the following equation by W.H. McAdams, TB. Drew, and G.S. Bays Jr., from the ASME trans. 62, 627-631 (1940). [Pg.1087]

Memanol water is an alcohol-base compound. It is less expensive than other organic compounds and, due to lower viscosity, has better heat transfer and pressure drop characteristics. It is used up to—35°C, Disadvantages are (I) considered more toxic than ethylene glycol and thus more suitable for outdoor applications (2) flammable and could be assumed to be a potential fire nazard. [Pg.1125]

Temperature-sensitive mixtures are to be separated. To avoid decomposition and/or polymerization, vacuum operation may then be necessary. The smaller liqmd holdup and pressure drop theoretical stage of a packed column may be particularly desirable. [Pg.1346]

Information on the liquid- and gas-handling capacity of the contacting device chosen for the pariicular separation problem. Such information includes pressure drop charac teristics of the device, in order that an optimum balance between capaital cost (column cross section) and energy requirements might be achieved. Capacity and pressure drop charac teristics of the available devices are covered later in this Sec. 14. [Pg.1350]


See other pages where And pressure drop is mentioned: [Pg.352]    [Pg.406]    [Pg.407]    [Pg.411]    [Pg.392]    [Pg.484]    [Pg.489]    [Pg.496]    [Pg.526]    [Pg.376]    [Pg.356]    [Pg.519]    [Pg.157]    [Pg.439]    [Pg.335]    [Pg.171]    [Pg.172]    [Pg.223]    [Pg.459]    [Pg.484]    [Pg.653]    [Pg.658]    [Pg.659]    [Pg.666]    [Pg.1037]    [Pg.1054]    [Pg.1065]    [Pg.1085]    [Pg.1346]    [Pg.1347]    [Pg.1352]   
See also in sourсe #XX -- [ Pg.104 ]




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Air velocity and pressure drop

Cyclone Flow Pattern and Pressure Drop

Diameter and Pressure Drop

Effect of Pressure Drop and Nozzle Size

Flood and Pressure Drop Prediction

Flooding and pressure drop

Flow Patterns and Pressure Drop of Ionic Liquid-Water Two-Phase Flows

Flow and Pressure Drop in Catalyst Beds

Friction factor and pressure drop

Frictional and dynamic pressure drop

General aspects Flow regimes, liquid holdup, two-phase pressure drop, and wetting efficiency

Hold-up, Pressure Drop, and Flooding Limits

Packed-column flood and pressure drop

Packing and pressure drop

Pall rings capacity and pressure drop

Power Consumption and Pressure Drop

Pressure Drop Inherent Limitations and Traps

Pressure Drop and Acceleration Length in Developing Regions

Pressure Drop and Heat Transfer

Pressure Drop and Heat Transfer in a Single-Phase Flow

Pressure Drop and Liquid Hold-Up

Pressure Drop and Weeping

Pressure Drop and the Rate Law

Pressure Drop of Irrigated Random and Structured Packings

Pressure Drop. Mass and Heat Transfer

Pressure drop and dispersion

Pressure drop and foam

Pressure drop and temperature

Pressure drop and void fraction

Pressure drop due to acceleration and collisions of particles

Pressure drop due to bends and fittings

Pressure drop in fittings and curved pipes

Pressure drop shell and tube

Pressure drop, limiting velocity and calculation of column dimensions

Process-side heat transfer and pressure drop

Shell and tube exchangers pressure drop

Shell-side heat-transfer and pressure drop (single phase)

Tower Pressure Drop and Flooding

Tube-side heat-transfer coefficient and pressure drop (single phase)

Velocity Field and Pressure Drop in Single-Phase Flows

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