JPH0453579B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION The present invention relates to a flow distribution device for supplying a gas/liquid mixture with a uniform flow distribution to an ebullated bed of a reactor. In particular, the present invention provides a method for handling oil streams or coal-oil slurry streams and gas streams such that the streams are initially substantially uniformly mixed and substantially uniformly distributed in the boiling catalyst bed. The present invention relates to a flow distribution device.

Experience in operating pilot plants and commercial reactors used in the H-oil and H-coal processes has shown that if the design of the inlet flow distribution in the reactor charge chamber is inadequate, the charge It has been found that difficult operational problems can occur such as coke formation in the chamber, poor flow distribution within the catalyst bed, local settling of the catalyst bed and coke formation in the catalyst bed. These problems have resulted in underutilization of the catalyst, resulting in frequent shutdowns of the reactor and shortened operating periods.

There is apparently no prior art known that provides an adequate solution to such flow distribution problems in fluidized bed catalytic reactors. For example, Johanson, in U.S. Pat. No. 3,197,288, describes the construction of a catalytic reactor using simple conduits for introducing inlet feed liquid and recirculating liquid into the plenum of the reactor. and Keith et al., in US Pat. No. 3,202,603, show the use of dual spargers at the lower end of the reactor. Also, Wolk
et al. in U.S. Pat. No. 3,540,995 disclose coal hydrogenation using a boiling catalyst bed reactor in which the feed liquid stream and the recycle liquid are introduced into a plenum chamber at the lower end of the reactor located below the flow distribution grid means. The operation of the method is generally disclosed. However, the introduction of the gas and liquid streams mentioned above into the plenum chamber of the reactor at high speeds requires more specialized equipment to properly mix and evenly distribute these streams. To that end, improved flow distribution device designs have been developed that provide a desirable uniform flow pattern within the plenum chamber of the reactor.

SUMMARY OF THE INVENTION The present invention provides a flow distribution device for uniformly feeding liquid hydrocarbon or slurry and gas into the plenum chamber of a reactor and upwardly into the boiling catalyst bed of the reactor.

The present invention provides a flow distribution device for supplying a gas-liquid mixture with a uniform flow distribution to an ebullated bed of a reactor, comprising: (b) a plenum chamber formed by a distribution grid located within the reactor below the boiling bed; (b) projecting into the plenum chamber from outside the reactor and having an inner end that (c) a conduit for transporting the gas/liquid mixture directed downwardly within the pneumatic chamber; (c) secured to an inner end of the conduit within the pneumatic chamber and directed downwardly towards the lower wall of the reactor; a deflector nozzle, the baffle nozzle having at least two spaced apart substantially parallel baffles, the innermost baffle comprising a bare plate, and at least one other baffle plate; The plate has a central opening and is located upstream of the baffle plate of the blank plate, so that the baffle nozzle mixes the gaseous and liquid substances supplied to the plenum via the conduit. and a baffle nozzle disposed in combination with the distribution grid and configured to uniformly upwardly supply a substantially uniform flow distribution of the gas/liquid mixture to the boiling bed. A flow distribution device for an ebullated bed reactor, characterized in that:

The present invention also provides a flow distribution device for supplying a gas-liquid mixture with a uniform flow distribution to an ebullated bed of a reactor, comprising: (b) a plenum chamber formed by a side wall and a distribution grate located in the reactor below the boiling bed; (b) projecting into the plenum chamber from outside the reactor and having an inner end; (c) a conical flow deflection device located at the lower end of the plenum, the flow deflection device being located at the bottom of the plenum; is secured to the lower end of the plenum, with its apex facing the inner end of the conduit, with the centerline of the flow deflector disposed substantially in line with the centerline of the inner end of the conduit; The flow deflection device is thus arranged to mix the gaseous and liquid substances supplied to the plenum via the conduit and to produce a gas/liquid mixture with a substantially uniform flow distribution, and is arranged in combination with the distribution grid. and a conical flow device configured to uniformly mix and feed the ebullated bed in an upward direction to the ebullated bed.

The present invention is particularly useful for handling hydrocarbon feed streams, such as petroleum and coal slurries, with hydrogen gas for uniform distribution within a boiling catalyst bed reactor, where the apparent velocity in the feed conduit is approximately
Particularly useful when speeds exceed 2.4 m/sec (8 ft/sec). Therefore, the term "gas/liquid mixture" herein refers to a gas/liquid mixture containing finely particulate solid matter.
It shall also include liquid slurry mixtures.

DESCRIPTION OF THE INVENTION In the present invention, a feed stream, such as a mixture of liquid slurry obtained from coal and hydrogen, is
(650 to 950°F) and 35 to 211 Kg/ ^cm2 gauge pressure (500 to 3000 psig) to the lower end of the reactor via a conduit and a rectifier, such as a disk-doughnut baffle nozzle. into a plenum chamber located at . The inner end of the conduit faces downwardly, and the baffle nozzle within the plenum chamber is located at the inner end of the conduit within the plenum chamber and faces downwardly toward the lower wall of the reactor. A baffle nozzle typically has a series of generally parallel spaced apart baffles within the inner end of the conduit at an angle of 45 to 90° to the axis of the conduit;
This baffle nozzle deflects the flow laterally, or radially, outward within the plenum. Inlet flow distributors or baffle nozzles for the plenum of a reactor using a fluidized bed of gas-liquid-solid materials are used to dissipate the kinetic energy of the flowing fluid supplied to the plenum. Provides a flow distributor without. The baffled nozzle prevents the recirculating flow of liquid and gas from ejecting into the plenum and evenly distributes the liquid flow within the plenum.

Depending on the operating conditions of the reactor and the available space within the plenum, the baffle nozzle can have various shapes. The liquid flow baffle nozzle may consist of at least two preferably circular baffles located at the outlet of the recirculating liquid conduit. If the nozzle is centrally located within the plenum, it is common for its baffles to be equidistant from each other. The bottom plate of the baffle nozzle is a bare plate that deflects the inlet flow laterally to prevent liquid from impinging directly on the bottom of the plenum. The other baffle or distribution plate of this baffle nozzle has a central opening and is sized to intercept a portion of the liquid flow and to deflect it laterally or radially outwardly into the plenum chamber. do.
These lateral flow channels are oriented to sweep the bottom of the plenum, eliminating stagnation areas, providing good gas/liquid (or gas/liquid solid material slurry) mixing, and ensuring that the flow distribution grid The flow upwards through the openings into the boiling bed is approximately uniform.

The proportion of total material flowing radially outward from the spacing between each baffle plate can be varied by selecting the dimensions of the baffle nozzle, but typically a larger proportion of the flow exits from the lowest spacing. . In a typical baffle nozzle design, about 40-45% of the inlet liquid flow is deflected by the innermost bottom plate, about 25-35% by the middle plate, and the remaining flow is deflected by the first plate. Deflect radially outward with a plate. In the case of nozzles with baffles that enter the plenum from one side but are not located on the longitudinal axis of the plenum, the deflector should be placed at a varying angle of approximately 0 to 10° with the adjacent deflector. to uniformly distribute the gas/liquid flow within the plenum chamber.

For small diameter reactors, less than about 1.5 m (5 ft) internal diameter, the feed liquid and gas streams are mixed with the reactor's recirculating liquid outside the reactor and this mixture is then added to the reactor's plenum chamber. As will be explained below, it is usually more convenient to use a baffled nozzle as shown in FIG. 1 to achieve even distribution. For reactors having diameters greater than about 1.8 m (6 feet), it is recommended to introduce the feed liquid and gas mixture into the plenum chamber of the reactor through a separate baffled nozzle. Normally desirable. For example, it is common to install a circular or annular perforated sparge ring above the plenum, which distributes the feed gas-liquid mixture uniformly within the plenum of the reactor. It can be used for dispensing. By creating a pressure drop through the sparge ring and directing the gas-liquid mixture flow from the sparge ring downward to dissipate most of the kinetic energy of the flow in the liquid, the small bubbles and the feed liquid are separated. A uniform flow consisting of This kinetic energy is used to increase the intensity of back-mixing of gas and liquid within the plenum. The pressure drop through the opening of the sparge ring typically ranges from ¹ to 15 psi for typical heavy crude oil reforming and coal liquefaction processes.

In another embodiment of the invention, the flow distributor comprises a conduit and a conical flow deflection device, the bottom of which is fixed to the lower wall of the plenum, and the apex of which is fixed to the interior of the conduit. Facing the end, the centerline of the flow deflection device is disposed substantially in line with the centerline of the inner end of the conduit.

The inlet flow distributor described above is used in combination with a distribution grid upstream of the distribution grid of the reactor to provide an excellent flow distribution device for a boiling catalyst bed reactor. The pressure drop through the baffle nozzle at rated flow rate is typically 5-25% of the total pressure drop through both the baffle nozzle and the distribution grid. The distribution grid can be a perforated plate, but
Preferably, the distribution grid comprises a number of vertical tubes, each of which is provided with a cap on its upper end. This flow distribution device of the present invention provides excellent gas-liquid contact and gas mixing within the plenum chamber of the reactor, eliminating the undesirable phenomenon of fluid flow directly impinging on the distribution grid and filling the plenum. Minimize coke formation in the air chamber and catalyst bed supported on the distribution grid.

The invention will be further described with reference to FIG. 1st
As shown, an inlet conduit 10 is inserted into the pneumatic chamber 12 of the reactor 14 . The conduit 10 includes a flow distributor 16 in the form of a baffle nozzle or disc-doughnut, which points downwardly within the plenum and supplies a mixture of liquid and gas to the plenum. This mixture then flows uniformly upwardly through the openings 19 of the distribution grid 18 and into the boiling catalyst bed 20 . The liquid in the reactor is withdrawn from above the boiling catalyst bed 20 via a central conduit 24 to a recirculation pump (not shown) from which it is pumped along with fresh feedstock liquid and gas via an inlet conduit 10. Nozzle with deflector plate 1
Recirculate to 6. The plenum chamber 12 has a height equal to that of the conduit 10.
Preferably, the diameter of the flow distribution grid 18 is between 4 and 12 times the inner diameter of the conduit 10.

As shown in more detail in FIG. 2, the baffle nozzle 16 includes at least one top annular baffle plate 30, the annular plate 30 having a central opening 31;
The aperture 31 is located upstream of the bare bottom circular plate 32, all of which are held together by three equally spaced structural bars 33 circumferentially. Preferably, the structural bar 33 is located at the outer edge of the baffle plate. The central opening 35 usually becomes smaller and smaller.
an additional annular baffle plate 34 having an annular shape located intermediate the top baffle plate 32 and the bottom baffle plate 32;
A baffle nozzle configuration may be preferred to provide a more radial distribution of flow from conduit 10. It is preferred to have a greater proportion of the flow exit from the lowermost spacing, since the fluid travels a longer distance within the plenum 12 before reaching the distribution grid 18. In the case of a baffle nozzle 16 having three plates, the plate dimensions are such that approximately 40-45 volume percent of the fluid flow is deflected radially outwardly by the bottom baffle plate 32 and approximately 25-35 volume percent of the fluid flow is deflected radially outwardly by the bottom baffle plate 32. Preferably, % of the flow is deflected outwardly by the second baffle plate 34 and the remainder of the flow is deflected radially by the top baffle plate 30. If required, at least one flow straightening vane
A vane 36 can be centrally located inside the conduit 10 in a longitudinal direction to provide a nearly non-directional flow pattern reaching the baffle nozzle 16. Such a baffle vane 36 is particularly useful when the deflection angle of the fluid flowing through the tube 10 exceeds about 30°.

FIG. 3 shows another example of the fluid flow distribution device of the present invention. In this example, the baffle nozzle 16 (in the dashed circle, corresponding to FIG. 2) is centrally located in the bottom part of the plenum chamber 12 below the distribution grid 18;
Directed downwardly, it is located a distance of 1.0 to 2.0 times the inner diameter of the inlet conduit 10 above the bottom of the plenum 12 of the reactor. Distribution grid 18 has an inner diameter of 1.91 to 3.81 cm
(0.75 to 1.5 inches) with a large number of vertical tubes 26;
Preferably, the vertical tubes 26 protrude below the grid by a distance of 4 to 10 times their inner diameters. The vertical tubes 26 project upwardly from the distribution grid a distance of about 1.5 to 4 times the inner diameter of the tubes. A cylindrical cap 28 is provided over the upper end of each vertical tube 26 and spaced from the vertical tube 26, and the cap 28 is attached to the vertical tube 26 by a suitable structural member (not shown).
We strongly support it. Cap 28 always contains catalyst solid particles 22 even in the absence of upward fluid flow through vertical tube 26, as may occur during operational disruptions or process shutdowns.
The arrangement is such that no water can enter the vertical tube 26 from the boiling bed.

A circular or annular sparse ring 40 is provided above the baffle nozzle 16 to uniformly distribute the gas and liquid flow in the upper portion 12a of the chamber. The sparge ring 40 has spaced apart openings 41 on its underside. The sparge ring 40 surrounds the downcomer conduit 24, and the sparge ring 40 has an inner diameter of more than about 8 feet. It is particularly useful for large diameter reactors such as A large number of sparge rings 40 are spaced apart. The openings 41 are sized to create a uniform pressure drop and positioned so that the flow is directed downwards so that most of its kinetic energy is dissipated and the back-mixing effect of gas and liquid within the plenum 12 is increased.

FIG. 4 shows still another example of the present invention. In this example, the flow distributor consists of a conduit 10 and a conical flow deflection device 46, the flow deflection device 46 being centrally located within the bottom portion of the plenum chamber 12, the bottom surface of which is connected to the bottom wall of the plenum chamber. It is fixed to 49. flow deflection device 4
The apex 48 of 6 is located in line with the centerline of the downwardly directed end 11 of the inlet conduit 10 to deflect flow from the conduit 10 substantially uniformly radially outward toward the bottom wall of the plenum chamber 12. . The conical surface of the flow deflector 46 may be straight or curved outwardly at the lower end to facilitate gradual outward deflection of the flow of the gas/liquid mixture within the plenum. Therefore,
The flow deflection device 46 acts in the same manner as in the baffle nozzle 16, so that the total flow is directed radially outwardly towards the wall of the plenum. A circular or annular sparge ring 40 is provided in the center of the plenum chamber 12 and above the flow deflection device 46 as in the structure of FIG.

Next, the present invention will be described with reference to Examples, but the present invention is not limited to these Examples.

EXAMPLE In a coal hydrogenation plant (200 tons/day, Cutlettsburg H-coal pilot plant reactor) equipped with a boiling catalyst bed reactor of 1.5 m (5 ft) internal diameter and using the H-roll process for coal liquefaction. , the feedstock coal slurry and gas were mixed with the recycle fluid stream from the ebullated bed outside the reactor. This entire combined stream is then secured to the downwardly facing inner end of a conduit entering the plenum chamber from the side, as shown in FIG. 1, which is an example of the device of the invention. A baffle plate was fitted to allow distribution through a downwardly pointing nozzle. As a result of placing the baffle nozzle in the plenum chamber, coking in the catalyst bed due to poor flow distribution within the boiling catalyst bed of the reactor was virtually eliminated.

In a commercial H-coal plant (18,000 tons/day) reactor with an internal diameter of 3.4 m (11 ft),
Fitted within the plenum chamber of the reactor are three sloping baffles fixed to the downwardly facing inner ends of the conduits entering the plenum laterally into the plenum chamber and dispersing the flow of the recirculating liquid slurry. A circular sparge ring was installed above the nozzle to distribute the feed liquid slurry and gas.

Commercial H-oil plant with internal diameter of 3.0 m (10 ft) (5565 Kl/day (35000 barrels/day))
In this reactor, three horizontal plates are installed in the plenum chamber of the reactor as an inlet flow distribution device to distribute the recirculating liquid flow from the boiling bed, with a centrally located vertical nozzle and a vertical nozzle located above the nozzle. A sparge ring was installed to uniformly distribute the flow of liquid and gas feedstocks.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of an example of the device of the present invention, and FIG.
FIG. 3 is an enlarged cross-sectional view of another example of a baffle nozzle for an apparatus according to the invention; FIG. An example longitudinal section, FIG. 4, is a longitudinal section of a further example of the device of the invention, similar to FIG. 3, but with a centrally located conical flow deflection device. DESCRIPTION OF SYMBOLS 10...Inlet conduit, 11...Downward end of the inlet conduit, 12...Publication chamber, 12a...Upper part of the purge chamber, 14...Reactor, 16...Nozzle with baffle plate (flow distributor) , 18...distribution grid, 19...
...Opening, 20... Boiling catalyst bed (boiling bed), 22...
...catalyst solid particles, 24... central conduit (downward conduit),
26... Vertical tube, 28... Cap, 30... Top annular deflector plate (upper first deflector plate), 31
... Central opening, 32 ... Bottom circular deflector plate (lowest third deflector plate), 33 ... Structural bar, 3
4... Additional annular deflection plate (intermediate second deflection plate), 35... Central opening, 36... Rectification vane, 4
0... Sparge ring, 41... Opening, 46
...conical flow deflection device, 48 ... apex, 49 ...
...Bottom wall.

Claims (1)

Claims: 1. A flow distribution device for supplying a gas/liquid mixture with a uniform flow distribution to an ebullated bed of a reactor, comprising: (a) a lower end of the reactor; (b) a plenum chamber formed by a side wall and a distribution grate located below the boiling bed in the reactor; (b) projecting into the plenum chamber from the outside of the reactor and having an inner end; (c) a conduit for transporting a gas/liquid mixture with a portion facing downwardly within the plenum chamber; a nozzle with a baffle facing downwardly, the baffle nozzle having at least two substantially parallel baffles spaced from each other, the innermost baffle comprising a bare plate; The other baffle plate has a central opening and is located upstream of the baffle plate of the blank plate, so that the baffle nozzle is capable of discharging gaseous substances and liquids supplied to the plenum via the conduit. a baffle plate arranged in combination with the distribution grid and configured to uniformly upwardly supply a substantially uniform flow distribution of the gas/liquid mixture to the boiling bed; A flow distribution device for an ebullated bed reactor, characterized in that it comprises a nozzle. 2. The flow distribution device of claim 1, wherein the spaced apart baffles are disposed within the inner end of the conduit at an angle of 45 to 90 degrees to the axis of the conduit. 3. The nozzle with a baffle plate is located in the center of the plenum chamber, and the axis of the conduit entering the plenum chamber is 45 to
Claim 1 which forms an angle of 90°
Flow distribution device as described in Section. 4. The nozzle consists of three circular or annular deflectors, the upper first deflector having a central opening, and the intermediate second deflector being smaller than the opening of the upper first deflector. 2. A flow distribution device according to claim 1, having a central opening and wherein the third lowermost baffle plate is a bare plate. 5 The central opening of the upper first baffle plate has a diameter of 0.6 to 0.75 times the inner diameter of the conduit, and the central opening of the intermediate second baffle plate has a diameter of 0.4 to 0.5 times the inner diameter of the conduit. Claim 1 having a diameter
Flow distribution device as described in Section. 6. Claim 1, wherein the baffle plates are spaced apart by a distance equal to 0.3 to 0.5 times the inner diameter of the conduit.
Flow distribution device as described in Section. 7. The flow distribution device of claim 1, wherein the fluid pressure drop through the baffle nozzle is between 5 and 25% of the total fluid pressure drop through the baffle nozzle and the distribution grid. 8. The flow distribution device of claim 1, wherein the conduit includes at least one baffle vane located upstream of the baffle nozzle. 9. The flow distribution device of claim 1, wherein said distribution grid comprises a number of vertical tubes, each vertical tube having an upper end covered with a cap. 10. The flow distribution device of claim 1, wherein a circular or annular sparger is provided within the plenum below the flow straightener grid and above the conduit. 11. A flow distribution device for supplying a gas/liquid mixture with a uniform flow distribution to an ebullated bed of a reactor, comprising: (b) a plenum chamber formed by a distribution grid located in the apparatus below the ebullating bed; (c) a conical flow deflection device located at the lower end of the plenum, the flow deflection device having its bottom surface facing downwardly in the plenum; affixed to the lower end of the flow deflector, with its apex facing the inner end of the conduit, the centerline of the flow deflector being substantially in line with the centerline of the inner end of the conduit, thereby directing the flow of the flow deflector. A deflection device mixes the gaseous and liquid substances supplied to the plenum via the conduit and is disposed in combination with the distribution grid to uniformly mix the gas/liquid mixture with a substantially uniform flow distribution. and a conical flow deflection device configured to feed upwardly into the ebullated bed. 12. The flow distribution device of claim 11, wherein the conduit comprises at least one baffle plate located upstream of the flow deflection device. 13. The flow distribution device of claim 11, wherein said distribution grid comprises a number of vertical tubes, each vertical tube having an upper end covered with a cap. 14. The flow distribution device of claim 11, wherein a circular or annular sparger is provided within the plenum below the baffle grate and above the conduit.