Distributor gravity

Liquid distributors function to spread an even distribution of liquid over the packing bed. Liquid distributors are commonly broken down by motive force into pressurized or gravity distributors. Pressurized distributors include pipe-oriflce distributors and spray distributors. Gravity distributors include pan-oriflce distributors and trough distributors. 

Spray Towers These are simple gravity extractors, consisting of empty towers with provisions for introducing and removing liquids at the ends (see Fig. 15-32). The interface can be run above the top distributor, below the bottom distributor, or in the middle, depending on where the best performance is achieved. Because of severe axial back mixing, it is difficult to achieve the equivalent of more than one or two theoretical stages or transfer units on one side of the interface. For this reason they have only rarely been applied in extraction applications. 

The number of irrigation or drip-points or entrance points per square foot of flat surface of the tower should be uniform for orifice, weir-type gravity, or pressure distributors, and need not exceed 10 points/ft [82]. This imiformity must not be disturbed by support rings for supporting the distributor itself. The distribution must include the area adjacent to the wall, and the design must not force more liquid at the wall where it contacts the packing. Uniformity of points of distribution to the packing surface is extremely important. The volume flow per point must be carefully calculated. 

These distributors are fabricated of pipe lengths tied to a central distribution header (usually) %vith orifice holes drilled in the bottom of the various pipe laterals off the header. This style of distributor can be fed by pressure or gravity for clean fluids. The gravity feed is considered better for critical distillation application when uniformity of the flow of the drip points (or flow points) through out the cross-section of the tower is extremely important, and is excellent for low flow requirements such as below 10 gpm/ft2 [131]. 

All distributors which rely on the gravity flow of liquid must be installed in the column level, or maldistribution of liquid will occur. 

Both Fig. 37 and Fig. 39 show solid particles highly dispersed as a dilute phase in the oscillating fluid, either gas or liquid, without evidence of any bubbles. When a packed bed of solid particles was subjected to the action of an oscillating liquid, however, only the upstroke portion of the periodic fluid motion was capable of dispersing the solid particles against the action of gravity, while during downstroke they fell back onto the distributor plate. 

Figure 11.6 Examples of methanol synthesis converters (a) tube-cooled, low-pressure reactor A nozzles for charging and inspecting catalyst B outer wall of reactor as a pressure vessel C thin-walled cooling tubes D port for catalyst discharge by gravity (b) quench-cooled, low-pressure reactor, A,B,D, as in (a) C ICI lozenge quench distributors (Twigg, 1996, pp. 450, 449 reproduced with permission from Catalyst Handbook, ed. M.V. Twigg, Manson Publishing Company, London, 1996.)...

Vapor-Liquid Gravity Separator Design Fundamentals The critical factors in the performance of a horizontal separator are the vapor residence time and the settling rate of the liquid droplets. However, two other factors enter into the design—the vapor velocity must be limited to avoid liquid entrainment, and there must be sufficient freeboard within the vessel to allow for a feed distributor. For vertical separators, the design is based on a vapor velocity that must be less than the settling velocity of the smallest droplet that is to be collected, with due allowance for turbulence and maldistribution of the feed. The vapor residence time is a function of the vapor flow rate (mass), vapor density, and volume of vapor space in the separator, based on the following ... 

The catalyst is a fixed bed. Flows of gas and liquid are cocurrent downwards. Liquid feed is at a such a low rate that it is distributed over the packing as a thin film and flows by gravity, helped along by the drag of the gas. This mode is suited to reactions that need only short reaction times, measured in seconds, short enough to forestall undesirable side reactions such as carbon formation. In the simplest arrangement the liquid distributor is a... 

The specific gravity range is from 1.45 to 2.00. The principal use of melamine compounds has been in the dinnerware field. They are widely used in electrical switch gear applications where arc track resistance is very important. In some cases the melamine phenolic compounds are used to produce electrical switch gear where arc track requirements are not so severe. Other applications are ignition systems (distributor cap), housings, and other decorative applications. 

In a circulating FBC system, the bed is fluidized by air passing through a wall-mounted distributor.15 Combustion occurs in the same way as in the bubbling FBC. Bed material is gravity fed down into the bed.15 Fuel is fed into the... 

Redistributor design is similar to gravity distributor design. The orifice type is most popular (Fig. 14). A notched-through type requires a liquid collection device above it to feed the liquid onto the distributor. Often, the gas risers are equipped with caps to prevent liquid from dropping through the gas spaces. 

Bed of coal descending under the influence of gravity Mechanical grates/distributors... 

Table I shows the size ranges and concentrations of the slurries of silica and iron oxide in isoparaffin and water, that were utilized in the tests. From the stirred, baffled reservoir tank, which was approximately the same volume as the columns, slurry was pumped with a diaphragm pump, using a tranquilizer to even out the flow, into the bottom of the 12.7 cm column, and above the distributor for the 30.5 cm column. In the 12.7 cm column, therefore, slurry passed with the gas through the distributor plate for V- >0. At the top of the column, the slurry was separated from the gas, and returned by gravity to either the reservoir tank, or to a calibrated volume used for slurry flow measurement.

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