Inlet distributor

Reactor Internals and Unit Hardware. Requirements for mixing feed components or separating products may determine minimum pilot unit size. If reactants caimot be premixed before they are passed into the reactor, the effectiveness of the inlet distributor in mixing the reactants can markedly affect reactor performance. This is especially tme for gases, multiple phases, or Hquid streams of greatly different kinematic viscosities. 

Dislribttlors Most spray columns operate with the drops being formed at the ends of jets from the dispersed phase inlet distributor. The orifices or nozzles for introducing the dispersed phase are usually not smaller than 0.13 cm (0.05 in) in diameter in order to avoid clogging, nor larger than 0.64 cm (0.25 in) in order to avoid formation of... 

Figure 52 is a representation of a complete module. For clarity, the vessel and inlet distributor have been omitted. The actual outside diameters of individual fibers range from 3 to 10 mils, depending on manufacturer. 

For services where ambient or inlet temperamres may fall below 0°C, flashback protection is provided by a special seal drum or loop seal in the inlet line. This equipment is designed specifically for the particular liquid and vapor materials being flared. In these cases a 150 mm minimum water layer is included in the bottom of the pit to prevent oil seepage into the ground, and the hydrocarbon inlet distributor is mounted 150 mm above the water surface. Details of the inlet distributor are shown in Figure 5. 

Pilots and Igniters - Two gas-fired pilots with igniters are installed adjacent to the inlet distributor. The igniter assembly and pilot gas valves must be located remote from the flare for protection of personnel and equipment. This restricts igniter selection to the forced air supply type. Location of these components should be such that the calculated radiant heat density at maximum load does not exceed permissible levels for personnel exposure. Because of the potential hazard of release of unignited hydrocarbons at ground level, a flame scanner (suitably shielded and aircooled and cotmected to an alarm in the control house), is provided for each pilot. 

Figure 10-21B. Impingement fluid-flow pattern with annular inlet distributor. (Used by permission Brown Root, Inc.)...

The main model parameter, the mean bubble diameter, db, can be estimated using various correlations. It depends on the type of particle and the nature of the inlet distributor. For small, sand-like particles that are easily fluidized, an expression is given for db as a function of bed height x by Werther (Kunii and Levenspiel, 1991, p. 146) ... 

In a typical fixed-bed carbon column, the column is similar to a pressure filter and has an inlet distributor, an underdrain system, and a surface wash. During the adsorption cycle, the influent flow enters through the inlet distributor at the top of the column, and the groundwater flows downward through the bed and exits through the underdrain system. The unit hydraulic flow rate is usually 2 to 5 gpm/ft2. When the head loss becomes excessive due to the accumulated suspended solids, the column is taken off-line and backwashed. 

To increase the surface area of the stationary phase for CEC separation, a collocated monolithic support structure (COMOSS) was constructed in a Si chip. A polystyrene-sulfonic acid stationary phase was then immobilized [349]. Design of the COMOSS required that the combined cross sectional area at the column head to be the same at any point in the inlet distributor [644]. A study for the reduction of band broadening in COMOSS was also reported [645]. 

In nonagitated (static) extractors, drops are formed by flow through small holes in sieve plates or inlet distributor pipes. The maximum size of drops issuing from the holes is determined not by the hole size but primarily by the balance between buoyancy and interfacial tension forces acting on the stream or jet emerging from the hole. Neglecting any viscosity effects (i.e., assuming low dispersed-phase viscosity), the maximum drop size is proportional to the square root of interfacial tension a divided by density difference Ap ... 

Considerable attention was given to the design of the reactor internals including the inlet distributor, outlet collector and thermocouple locations as shown in Fig. 2. Laboratory simulation and testing of catalyst characteris tics helped to develop catalyst bed support criteria and loading procedures to ensure uniform packing and bed density for good flow distribution. 

Feed inlet distributors are recommended for large-diameter singlepass trays (207, 354). In multipass trays, feed and reflux distributors are essential to ensure uniform distribution. The only exceptions are... 

The MRT Purifier, developed for Tecnimont-KT in the framework of FISR project, has been designed to house five membrane modules and operate at 450°C and up to 25 barg. Each module consists of two double sided, planar 30 cm X 12 cm membrane panels welded in series. Each panel has a palladium (Pd) alloy active membrane area of 0.03 m per side for a total installed membrane area of 0.6 m in the purifier. The modules are housed in a rectangular core which, along with the inlet distributor, promotes uniform reformate flow across the membrane modules. The core assembly (Fig. 3.11) is housed inside a pressure vessel. 

Size of dispersed liquid phase is given in Section 5.3. Horizontal cylindrical vessel with allowance for 20 min residence time for the water phase. Keep liquid velocity < 10 L/s m. Carefully size the inlet distributor for the liquid so that inlet velocity is < 0.4 m/s. 

Startup after catalyst replacement, Ap < expected and conversion < standard [maldistribution] and axial variation in temperature/larger size catalyst. Startup after catalyst replacement, conversion < standard and Ap increasing [maldistribution and axial temperatures drfferent] /feed precursors present for polymerization or coking. Startup after catalyst replacement, Apfor this batch of catalyst > previous batch catalyst fines produced during loading/poor loading. Startup after catalyst replacement, conversion < specifications per unit mass of catalyst and more side reactions [maldistribution] /faulty inlet distributor/faulty exit distributor. 

The sand bed inside the DynaSand filter continually moves downwards, through the dirty sand hopper, rmtil it readies the bottom of an air lift pun, see Figure 6.8. Some previously deposited solids on the sand grains are removed in the turbulent air hft punq>, additional sand cleaning takes place in the washbox, where some filtered water is admitted to wash the sand in coimter-current flow. The dean sand r utns to the top of the bed. The washwater and fine solids flow over a weir into the washwater outlet. Process water is fed into the filter through the inlet distributor, and flows counter-currently to the sand bed. Cleaned water emerges fiom the bed, flows over an outlet wdr and leaves via the filtrate outlet. 

The tip of the thermocouple well which broke off, the so-called lost part , was carried by the sodium flow to the superheater inlet distributor where it lodged and from which it was later recovered. The collision points of the lost part with the internals of the loop were deduced and the damage to the loop was estimated from the corresponding damage to the surface of the lost part. It was concluded that the integrity of the loop had not been impaired. 

Liquid inlet distributor can be tray type (needs hangar bolts or side supports) or as a number of perforated pipes. 

A variety of scaleup models for trickle beds are presented in the literature. All the models assume that even distribution of the fluid over the entire top catalyst bed surface will be achieved with the proper design of inlet distributor hardware. 

Figure 3.12 Restriction of the inlet distributor causes entrainment of the catacarb solution.

Stationary inlet distributor Inlet pressure seal... 

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