JPH04110032A - Cooling assembly - Google Patents

Abstract

PURPOSE: To improve the temperature uniformity of a fluid stream to a catalyst bed after introducing a cooling fluid by composing a cooling assembly of a cooling-fluid inlet zone, a cooling-mixing zone, a jet-agitating-mixing zone and a distributing zone. CONSTITUTION: The cooling-fluid inlet zone (A) which is equipped with a cooling-fluid introducing pipe (17) and receives a fluid from a catalyst bed (12), and the cooling-mixing zone (B) which is communicated with the zone (A) through a central opening part (E) are provided. A bottom plate (29) having plural openings (21) at an annular ring in the periphery is equipped in the zone (B). A fluid coming into the zone (B) is allowed to shift its direction outward and to the radius direction by the bottom plate (29) before it comes out through the plural openings (21). Buffles (24) positioned by the ring are further installed on the bottom plate (29) between the center of the plate (29) and the openings (21). Also in a jet-agitating mixing zone (C) plural pipes (22) having slot holes directed to specified angles and a central opening part (F) are arranged. A distributing zone (D) is communicated with the central opening part (F).

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICATION The present invention relates to a cooling assembly particularly suitable for processing fluids in a series of separated catalyst beds where precise control of fluid temperature and composition is desired. Regarding.

PRIOR ART Many catalytic processes have been carried out in reactors containing a series of separated catalyst beds. In such processes, mixing means such as cooling boxes are often placed between the catalyst beds. The purpose of the cooling box is to quickly and efficiently mix the fluid streams being processed in the reactor as they proceed from one catalyst bed to the next. As will be readily appreciated, the better the mixing, the better the temperature and reaction will be controlled and therefore the better the overall reactor performance.

An example of such a cooling box is US patent series 3.480°4.
No. 07, No. 3.723.072, No. 3.880.96
No. 1, and No. 3.895.919.

PROBLEM TO BE SOLVED BY THE INVENTION These prior art cooling boxes had unique advantages over other then known cooling boxes, or did they have the advantage of reducing the flow of fluid to the catalyst bed after introducing the cooling fluid? Experience has shown that the temperature and flow uniformity of is not achieved to the desired degree.

As a result, there remains a need for an improved cooling assembly that improves the temperature uniformity of fluid flow to the catalyst bed after the cooling fluid is introduced.

SUMMARY OF THE INVENTION In accordance with the present invention, a cooling assembly having improved mixing efficiency or a series of mixing zones, ie, cooling fluid inlet zones, is provided.
It consists of a cooling mixing zone, a jet stirring mixing zone, and a dispersion zone. In the cooling fluid inlet zone, a cooling fluid is introduced into the reactant fluid from the upper catalyst bed. The cooling fluid is introduced through the holes in the cooling tube, creating a jet of cooling fluid;
The cooling fluid flows into and mixes with the typically partially reacted reactant fluid from the upper bed. This mixing zone is separated from the cooling mixing zone by a horizontally arranged plate with a central opening. The reactant fluid and cooling fluid enter the cooling mixing zone through a central opening in the plate separating the two zones and impinge on the bottom plate of the cooling mixing zone where the gases are redirected radially outward. It passes around a series of baffles. To introduce cooling gas and process fluid into the jet-stirred mixing zone, a plurality of tubes are arranged in an annular ring near the periphery of the bottom plate of the cooling mixing zone. The fluid stream exiting the cooling mixing zone is thus introduced in a spiral direction into the annular jet-stirred mixing zone where the fluids are further mixed by mutual entrainment. The fluid is then directed downwardly through a central opening in the plate separating the jet stirring zone from the dispersion zone. The distribution zone is provided with a distribution tray for distributing the fluid to the underlying catalyst bed.

This and other features of the invention will be better understood by reading the detailed description in conjunction with the accompanying drawings.

EXAMPLES Referring first to FIG. 1, a multi-bed catalytic reactor is indicated generally by the reference numeral 10 and has a generally cylindrical sidewall 1) surrounding a plurality of catalyst beds. Catalyst bed 12.13 is the first
As shown in the figure. The catalyst bed is supported by a catalyst bed support 14, such as a perforated plate, a mesh covered grid, etc., that allows fluid to exit the bottom of the bed. As known in the art, to aid in dispersion of the gas as it enters the bed,
Furthermore, in order to prevent catalyst particles from scattering from the position where the catalyst is placed when the container is filled with the catalyst, a plurality of ceramic balls, Raschig rings, etc. are placed on top of the catalyst bed. In the embodiment of FIG. 1, the ceramic balls 15 are connected to the catalyst bed 13
Shown at the top of

Thus, each of the multiple catalyst beds within the reactor contains catalyst particles,
Consists of a lower support floor and a covering floor.

A cooling assembly is interposed between successive catalyst beds for introducing a cooling fluid into the slightly reacted fluid exiting the catalyst bed above the cooling assembly. As the process fluid enters the next catalyst bed, ie, as it flows downward through the reactor, a cooling fluid is introduced to adjust the temperature and composition of the process fluid.

As previously indicated, the cooling assembly of the present invention consists of four zones: a cooling fluid inlet zone, a cooling mixing zone, a jet mixing zone, and a fluid distribution zone. The cooling fluid population zone comprises the area below the catalyst bed support 14 and the top plate 16 of the horizontal arrangement of the cooling box. A tube or conduit 17 extends across the diameter of the reactor 10 in the cooling fluid inlet zone and has a plurality of outwardly directed holes 18 for directing the shed of cooling fluid into the cooling fluid inlet zone. It is ejected approximately perpendicular to the downward flow of fluid exiting the upper catalyst bed 12. Thus, the jet formed by the cooling fluid exiting the holes 18 of the cooling inlet tube 17 entrains and mixes with the fluid flowing from the catalyst bed above.

As shown, a horizontally disposed plate 16 separates the cooling fluid inlet zone from the cooling mixing zone. As can be seen, the plate 16 has a central opening through which fluid from the cooling inlet zone passes as it advances through the cooling assembly. As will be readily appreciated, the size of the central opening in plate 16 is a function of the allowable pressure drop across the plate.

Approximately 350mmAq (0,5psi) to 3500
As a general guide for pressure drops in the range of mm, Aq (5 psi), the open area ranges from about 1% to about 4% of the cross-sectional area of the reactor. The cooling mixing zone also comprises a horizontally arranged lower plate 29 in the vessel 10. Board 29 is board 2
There are a plurality of openings 2I arranged in an annular ring around 9. These openings 21 are best seen in FIGS. 2 and 3. Thus, fluid entering the cooling mixing zone through the central opening of plate 16 impinges on the solid central zone of plate 20, where it is redirected and passes through opening 21 of plate 29.
Flows radially outward toward.

A plurality of mixing baffles 24 are positioned in the cooling mixing zone of plate 29. This mixing baffle is located between the center of plate 29 and plate 2.
9 is arranged in a substantially concentric ring between the openings 21 in the outer periphery. These baffles 24 extend vertically upwardly a distance less than the distance between plates 29 and 16. For example, the baffle may extend from 1/3 to 2/3 of the height of the cooling mixing zone, preferably about half the height of the cooling mixing zone. As shown in FIG. 3, the baffles of the innermost ring are arranged at an angle with respect to the tangent to the circle on which the center of each inner baffle lies. Essentially, the flow vortices resulting from the fluid flow impinging on the baffle are directed to impinge on the baffle of the next annular ring. In effect, at least a portion of the fluid flowing radially outward toward the outer circumference impinges on the baffle.

Returning to FIG. 1 and also referring to FIG. 2, the jet agitated mixing zone is positioned below the cooling mixing zone. This jet agitation mixing zone is basically constituted by a plate 29 and a plate 26. As seen in FIG. 1, plate 26 has a vertically extending annular ring or arm portion 40 separating the body of plate 26 from plate 29. As seen in FIG. Plate 26 also has a large central opening. Overall, this opening ranges from about 25% to about 75% of the total cross-sectional area of the reactor, and about 5% of the total cross-sectional area of the reactor.
0% is preferred. A tube 22 is arranged around the plate 26;
It communicates with the opening 2I and extends downward from the plate 29. The tube 22 has an opening or slot 23 through which fluid flows. These slots 23 open inwardly to direct fluid radially into the jet mixing zone. but,
In the practice of the invention, the slots 23 are oriented at an angle with respect to a radial line such that the fluid exiting the tube 22 is ejected in a spiral direction, e.g. counterclockwise, thereby further promoting mixing by mutual entrainment. is particularly preferred. Thus, the slot 23 can be positioned between 0° and 90° relative to the radial line.
It may be oriented at an angle of about 15° to about 75°, with an orientation of 45° being most preferred.

After the fluids are mixed and rotated in the jet agitation mixing zone, they exit through the central opening in plate 26 and enter the fluid distribution zone.

The fluid distribution zone is constituted by the upper jet-stirring mixing zone plate 26 and a plate 28 extending horizontally across the reactor and containing a plurality of openings 30, with conduits 31 extending upwardly from the openings 30. A conventional bubble cap 32 is provided to control fluid flow through the dispersion zone.

In another embodiment of the invention, the cooling inlet pipe 17 may, of course, be an annular sparger ring arrangement, such as ring 47 in FIG.

In yet another embodiment of the invention shown in FIG. 5, the cooling inlet tube consists of a plurality of transverse arms 58 extending from a central manifold 57. Preferably, the openings in the cooling tubes are positioned to direct the cooling fluid substantially perpendicular to the fluid flow exiting the catalyst bed, as shown by the dashed lines and arrows.

The cooling assembly is also supported within the reactor by conventional techniques known in the art. Thus, as shown in FIG. 1, plate 28 is supported by annular shelf 34 while plate 16
．． 29 are each supported by shelves 36.38, each of which has a general support 37.39 rising from that shelf to the supported board.

Obviously, the various zones, openings,
The exact dimensions of the conduits etc. will depend on various factors such as the allowable pressure drop, the space between the reaction beds available in the cooling box, etc.

As will be readily appreciated, the present invention also includes various catalysts that homogeneously mix reactants, i.e., slightly reacted reactants, and a cooling fluid so as to control the temperature profile of the material or its composition, or both. Suitable for use in processes.

The fluid may be entirely gaseous or gaseous and liquid, depending on the nature of the process being carried out within the reactor. It will therefore be readily appreciated that there are many variations in the construction of a cooling box according to the invention, and that the invention has wide applicability in many catalytic processes. Accordingly, the invention is to be limited only by the scope of the claims that follow.

[Brief explanation of the drawing]

1 is a vertical cross-sectional view of a multi-bed catalytic reactor with a cooling box according to the invention; FIG. 2 is a detailed view of the cooling box outlet pipe according to the invention; FIG. FIG. 4 is a plan view of the bottom plate of the cooling mixing zone showing the arrangement of the perforations and baffle layout around the cooling mixing zone, and FIG. 5 is a schematic diagram of another sparge for introducing cooling fluid into the cooling box of the present invention. DESCRIPTION OF SYMBOLS 10... Reactor, 1)... Side wall, 12.13... Catalyst bed, 14... Catalyst bed support, 15... Ceramic balls, 16... Top plate, 17... Cooling inlet pipe, 21... Opening, 23... Slot, 24... Baffle, 29... Lower plate, 31... Conduit, 32... Bubble cap. DoFIG, 3

Claims (10)

[Claims] (1) a cooling fluid inlet zone including means for introducing a cooling fluid and adapted to receive a flow of fluid from the catalyst bed; and a cooling mixing zone communicating with the cooling fluid inlet zone by a central opening; The cooling mixing zone has a bottom plate with a plurality of openings in a surrounding annular ring, and fluid entering the cooling mixing zone is deflected by the bottom plate before exiting through the plurality of openings and is directed outwardly. and a baffle positioned in an annular ring on the bottom plate between the center of the bottom plate and an annular ring of a peripheral opening, and a jet-stirred mixing zone in communication with the surrounding opening. a plurality of tubes extending downwardly from the bottom plate of the cooling mixing zone and having slots oriented at an angle with respect to the radius of the cooling box for introducing fluid exiting the cooling mixing zone into the jet-stirring mixing zone; . A cooling assembly having improved mixing efficiency comprising: a central opening of the jet-stirred mixing zone; and a dispersion zone in communication with the central opening of the jet-stirred mixing zone. (2) The baffle is arranged at a predetermined angle with respect to a tangent to a circle in which the center of the baffle is located.
Cooling assembly as described in Section. (3) The baffles are arranged in a plurality of annular rings on the bottom plate to direct flow vortices resulting from the fluid flow impinging on the baffles to impinge on the baffles of the next annular ring. The cooling assembly according to item (1). (4) the cooling mixing zone is separated from the cooling fluid inlet zone by a horizontal plate having an opening, the baffle being about 1/1/2 of the distance from the bottom plate to the horizontal plate separating the cooling fluid inlet zone and the cooling mixing zone; 4. A cooling assembly as claimed in claim 3, extending vertically upwardly from 3 to 3/4 of a distance. (5) the means for introducing the cooling fluid into the cooling fluid inlet zone;
A cooling assembly according to claim 1, which is a fluid injector. (6) The fluid injector has an opening arranged to inject cooling fluid into the cooling fluid inlet zone substantially perpendicular to the flow of fluid from the catalyst bed.
Cooling assembly according to paragraph 5). (7) The openings of the tubes are oriented at an angle with respect to the radius of the cooling box so as to introduce the fluid introduced into the jet-stirring mixing zone in a swirling direction. cooling assembly. 8. The cooling assembly of claim 7, wherein the tube openings are oriented at an angle of about 15° to about 75° with respect to a radius of the cooling box. (9) the jet-stirred mixing zone is defined by a bottom plate of the cooling mixing zone and a horizontally disposed plate having a central opening and an upwardly extending annular ring side wall; A cooling assembly as claimed in claim 1, wherein: is located below the bottom plate. (10) A catalytic reactor of the type having at least one cooling box sandwiched between two catalyst beds, said cooling box consisting of a series of mixing zones, said mixing zone consisting essentially of: a cooling fluid inlet zone; , a cooling mixing zone, a jet agitated mixing zone and a dispersion zone, the cooling fluid inlet zone being adapted to receive the flow of fluid from the catalyst bed, and the cooling fluid inlet zone adapted to receive the flow of fluid from the catalyst bed. the cooling mixing zone is positioned below the cooling fluid inlet zone and separated by a horizontally disposed plate having a central opening; has a bottom plate with a plurality of openings in a surrounding annular ring, and fluid entering the cooling mixing zone is deflected and moved outwardly and radially by the bottom plate before exiting through the plurality of openings. further comprising a baffle positioned in the annular ring of the bottom plate between the center of the bottom plate and the annular ring of peripheral openings, the jet-stirred mixing zone being disposed below the cooling mixing zone, and a bottom plate having a central opening, and further comprising a plurality of tubes extending downwardly from the bottom plate of the cooling mixing zone in communication with a peripheral opening, the tubes communicating with the jet agitation of fluid exiting the cooling mixing zone. having slots oriented at an angle with respect to the radius of the cooling box for introduction into the mixing zone; A catalytic reactor comprising: a horizontally disposed plate disposed below a mixing zone and having a plurality of openings.