Liquid distributor

FIG, 14-64 Typical liquid distributors. (Cowtesy Notion Company, Akron, Ohio.)... 

The liquid distributor not dividing the hquid evenly over the column cross section. 

FIG. 14-80 Cost of internal devices for columns containing dumped packings, a) Holddown plates and support plates, (h) Redistributors, (c) Liquid distributors. [Pikulik and Diaz, Cbem. Eng., 84(21), 106 (Oct. 10, 1977).]... 

The term mist generally refers to liquid droplets from submicron size to about 10 /xm. If the diameter exceeds 10 /xm, the aerosol is usually referred to as a spray or simply as droplets. Mists tend to be spherical because of their surface tension and are usually formed by nucleation and the condensation of vapors (6). Larger droplets are formed by bursting of bubbles, by entrainment from surfaces, by spray nozzles, or by splash-type liquid distributors. The large droplets tend to be elongated relative to their direchon of mohon because of the action of drag forces on the drops. 

C. Liquid Distributor (see Figures 4-9). According to Strigle, This is the most important column internal from a process standpoint. A liquid distributor is required at all locations in the tower where an external liquid stream is introduced. High-performance distributors provide a flow rate variation per irrigation point that is a maximum of 5% of the average flow. The geometric uniformity of... 

D. Hold-Down Grid (see Figure 3). According to Strigle, Normally, the upper surface of the packed bed is at least 6 in. below a liquid distributor or redistributor. The bed limiter or hold-down plate is located on top of the packed bed in this space. It is important to provide such a space to permit gas disengagement from the packed bed. Such a space allows the gas to accelerate to the velocity neces-... 

Figure 4. Orifice deck liquid distributor. (Courtesy of Norton Chemical Process Products Corporation.)...

Valve trays Minimum liquid head on liquid distributor, in. 0.75-1 ... 

Liquid distribution in a packed bed is a function of the internal vapoi/liquid traffic, the type of packing employed, and the quality of the liquid distributors mounted above the packed bed. Vapor distribution is controlled by the internal vapor/liquid traffic, by the type of packing employed, and by the quality of the vapor distributors located below the packed beds. 

Fnr stripping service, as in a glycol or amine contactor (see Chapt 7 a bubble cap trays are the most common. In recent years, there has b growing movement toward crimped sheet structured packing. Improved vapor and liquid distributor design in conjunction with struc-... 

Adsorbers, distillation colunuis, and packed lowers are more complicated vessels and as a result, the potential exists for more serious hazards. These vessels are subject to tlie same potential haz. uds discussed previously in relation to leaks, corrosion, and stress. However, llicse separation columns contain a wide variety of internals or separation devices. Adsorbers or strippers usually contain packing, packing supports, liquid distributors, hold-down plates, and weirs. Depending on tlie physical and chemical properties of the fluids being passed tlirough tlie tower, potential liazards may result if incompatible materials are used for llie internals. Reactivity with llie metals used may cause undesirable reactions, which may lead to elevated temperatures and pressures and, ullinialely, to vessel rupture. Distillation columns may contain internals such as sieve trays, bubble caps, and valve plates, wliicli are also in conlacl with tlie... 

Figure 9-8E. Trough liquid distributor. Used by permission of U.S. Stoneware Co. (now, Norton Chemical Process Products Corp.).

Figure 9-8F. Typical design inlet liquid distributor using holes (orifices) on underside of distribution pipes. Note Number of side pipes adjusted to provide uniform entry per square foot of tower cross-section area. Holes at wall should be spaced on same basis.

Figure 9-8H. Orifice pan liquid distributor with round or rectangular chimneys and a flat floor sealed to vessel support ring. For a large vessel, it can be sectioned to pass through a manway. Used by permission of Jaeger Products, Inc., Bull.-1100.

Figure 9-8I. Multipan MTS-109 two-stage liquid distributor. Used by permission of Nutter Engineering, Harsco Corp., Bull. CN-4.

Figure 9-8J. MTS-109 Multipan two-stage liquid distributor for optimum liquid distribution for uniform flow for random and structured packings for low to moderate liquid rates, less than 5 gpm/ft. Also used for redistributor. Used by permission of Nutter Engineering, Harsco Corp., Bull. TI-1, under license from The Dow Chemical Co., protected by U.S. Patents No. 4,472,325 4,808,350 5,013,491.

Nutter offers an improved high performance random packing identified as Nutter Ring, see Figure 9-6K. To achieve the best performance from any random packing, the liquid distributor must be level and the distributor points of the discharging liquid to the packing must be uniformly distributed, see earlier discussion on this topic. 

The typical packed column has one or more beds, each consisting of packing, a support plate, a hold-down support plate, and a liquid distributor. 

The liquid distributor is the most important internal structure of a packed column. The distributor strongly influences packing efficiency. It must spread the liquid uniformly, resist plugging/fouling, provide free space for gas flow, and allow operating flexibility. 

Figure 4.15 Schematic of the experimental set-up of the [chip liquid/liquid distributor tube] reaction system [31],...

Figure 4.56 Nitrotoluene product formation at various acid-to-organic flow ratios using a reaction system with a liquid/liquid distributor and a tube at 90 C [31].

Figure 5.15 Schematic of the multiphase packed bed reactor. Gas inlet (A) liquid distributor (B) catalyst inlets (Q exit port manifold (D) [11].

Select and design the column internal features packing support, liquid distributor, redistributors. 

A full redistributor combines the functions of a packing support and a liquid distributor a typical design is shown in Figure 11.52. 

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