JPS59145287A - Method and device for dispersing liquid supplier in fluidized catalytic decomposition system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to fluid catalytic cracking of hydrocarbons. More specifically, the present invention disperses a liquid hydrocarbon feed into a stream of heated catalyst particles in a standpipe reactor, and combines the hot catalyst particle surfaces with finely divided liquid droplets. The present invention relates to an improved method for promoting catalytic action during the process.

A particular object of the present invention is to enable the finely divided hydrocarbon liquid droplets to come into direct contact with the hot catalyst particle surface, rather than contacting the liquid surface on the catalyst or the gas emanating from the liquid. be. This contact between the droplets and the hot catalyst provides at least one contact for discharge into the standpipe reactor.
This is facilitated by the provision of several hydrocarbon spray nozzles for the generation of mist. According to the invention, this misting nozzle has a swirling or centrifugal chamber.

This chamber is in direct contact with a full flow area orifice having a diameter that is substantially smaller than the diameter and area of the swirl chamber or the hydrocarbon liquid supply line connected thereto. At a pitch of at least 20° to the axis of said supply line and chamber! at least one pair of vanes to cause swirling or centrifugal rotation to the liquid entering the chamber, with no obstructions to the flow other than a small diameter orifice;
It is thereby desirable to convert the entire feed into a mist and feed it to the standpipe reactor. What is the area of the orifice?

Desirably, it is substantially equal to the area of flow through the vanes. Multiple nozzles of this type are arranged at equal intervals around the standpipe reactor and are recessed from the catalyst flow area to prevent nozzle erosion and direct heating by the thermal catalyst. It is desirable to do so. However, this recessed arrangement within the wall of a standpipe reactor does not allow for the flow of liquid from the orifice into the catalyst stream, or for dispersing the flow into finely divided liquid particles to produce the desired mist. It is only effective in cases where formation is not obstructed by walls. Such finely divided droplets.

The catalytic reaction between the gas and the catalyst surface is preferred over the thermal decomposition of the hydrocarbons because the direct contact with the heated catalyst particles results in more rapid vaporization from liquid to gas.

Particularly when catalysts containing zeolites are used, since the catalyst-hydrocarbon interaction is primarily a gas phase cracking process, such catalytic reactions preferentially yield hydrocarbon products in the intermediate fouling range. In contrast, the reaction between liquid hydrocarbons and catalysts involves primarily thermal decomposition, with gas and coke formation being predominant. Therefore, economically attractive intermediate (boiling) range hydrocarbons - pentane and higher molecular weight liquids -
is generated. Also, the small droplets of the feed are more completely vaporized and catalytically converted, due to the small amount of liquid remaining on the catalyst particles when separated from the overhead vapor after removal from the standpipe reactor. , the production of desired hydrocarbons is enhanced without significantly increasing the "coke" formed on the spent catalyst.

BACKGROUND OF THE INVENTIONPrior Art Fluid catalytic cracking of heavy petroleum fractions is one of the major refining processes for converting crude oil or partially refined petroleum into useful products, such as fuel for internal combustion engines and oil for heating. Fluid catalytic cracking (commonly known as "FCC") involves breaking a high-molecular-weight hydrocarbon liquid into finely divided solids at high temperatures in a standpipe or transfer line reactor. Contact with catalyst particles. The reactor is usually in the form of a standpipe.

The contact time of the substance is on the order of several seconds, such as 1 to 10 seconds, and is generally about 3 seconds or less. In order to optimize the production of gasoline and mid-boiling fractions, the contact time must be shortened in this way.

By appropriate selection of temperature and reaction time, the catalytic reaction is "quenched" so that the production of methane and carbon, the economically undesirable end products of this type of reaction, is minimized;
The desired product is the production of lint/mid-boiling oil. During this short reaction period, approximately 30” to 80% of
The hydrocarbon feed with an initial temperature of 0'F is approximately 1100
Sprayed onto the catalyst having a temperature of D to 1400°F.

As already mentioned, the present invention relates to a system for uniformly misting such a feed onto a thermal catalyst.

Generally, the mixture is fluidized by steam and hydrocarbon gas resulting from a hydrocarbonaceous feed that vaporizes on contact with a thermal catalyst. The reaction of the mixture is one with essentially instantaneous generation of large volumes of gaseous hydrocarbons. A mixture of hydrocarbon vapors and catalyst flows from the standpipe into a separation tank. In the separation vessel, the used catalyst is separated primarily by gravity and inertia forces acting on the catalyst and is returned to the regenerator through a portion of the stripper in a downward direction.

Fluidizing steam also generally flows upward through the falling catalyst and serves to strip hydrocarbon vapors from the spent catalyst. By flowing oxygen through the bed of spent catalyst in the regenerator, the coke, consisting primarily of carbon, on the spent catalyst is combusted to obtain heat for the process. The regenerated and heated catalyst is then recycled to the standpipe reactor.

All desired product hydrocarbon vapors are recovered overhead. Typically, this recovery is accomplished using one or more cyclonic separators with the plenum chambers connected to a common pipe and plumbed directly to the distillation column.

The vapor stream from the cyclonic separator extracts any residual or entrained catalyst fines. This catalyst fine powder is located at the bottom or lower part of the separation tank, and is collected while passing through a "Ditsoreg" connected to a stripper and returned to the regenerator.

Particular problems in the initial generation of hydrocarbon vapors.

If the hydrocarbon liquid is injected into the reactor riser and does not come into direct contact with the catalyst, the pyrolysis reaction will predominate over the catalytic reaction. Easy to produce things. That is,
The hydrocarbons in the feed are completely converted to gas and coke rather than mid-boiling hydrocarbon fractions. Prolonged contact of the unvaporized liquid hydrocarbons with the catalyst after they have been fed into the separation tank leads to further thermal decomposition, and the aforementioned final reactions are particularly likely to occur at high rates. Further, since such catalytic cracking is originally a gas phase reaction, it is an essential condition that the hydrocarbon vapor comes into contact with the catalyst.

It has been proposed in the past to use a nozzle for forming mist or fine droplets in a standpipe reactor.

Generally, such fine dispersions are obtained by using water vapor or other vaporizing substances, in which case a two-phase system of fluids is formed. A problem with such two-phase fluids is that the pressure drop across the spray nozzle is greater than with either fluid phase alone. Since the pressure drop across the nozzle when the nozzle dimensions and feed flow rate are constant has a significant effect on the size of the droplets formed by the nozzle.

This pressure drop is significant. It is of course also undesirable to add additional steam to the hydrocarbon feed. The water vapor added in this way must be recovered in a distillation column at the top of the column, which generally causes problems in the disposal of sour water. This is because oxides of carbon and carbon combine with water to form acids.

Despite these problems, steam has been used because it lowers the partial pressure of the hydrocarbons and thus reduces the resistance to vaporization of the feed stream by the catalyst.

U.S. Pat. No. 3,152 to Harp et al.
No. 065, Snyder's No. 3, 81
No. 2,029, GriffQl et al. No. 3.654,140, and McMahon
No. 3,071,540 to Bon et al. illustrates a feed nozzle for a fluid catalytic cracking system that injects steam or water co-currently with the hydrocarbon feed from an annular region around the hydrocarbon feed nozzle. It is something. These patents disclose the advantage of using a steam "shroud" around a nozzle located directly within the standpipe reactor to atomize the hydrocarbon feed into the catalyst stream. . According to Sharp et al., the orifice opens into the mixing chamber before ejecting the mixture. A helical vane around a straight flow pipe for hydrocarbon liquids swirls the water vapor to promote atomization of the hydrocarbon feed. This nozzle is located within the catalyst stream. Sharp et al. also teach an alternative method of mixing and discharging a mixture by exchanging liquid and gas streams through concentric nozzles, with water vapor flowing through the center and liquid swirling around the water vapor. Snyder et al. disclose that the hydrocarbon feed flows through a surrounding water nozzle that co-currently cools the feed nozzle to prevent coking and that the water and feed Disperse the mixture into fine droplets. Gritzel et al. disclose the use of a penturi in the feed vessel to act as a nozzle disposed within a standpipe reactor for the combined flow of steam and hydrocarbon feed. Alternatively, Snyder et al. discloses the use of a helical member within the hydrocarbon feed nozzle itself and the use of an ambient flow of water vapor to disperse the fluidized hydrocarbon feed into small droplets.

In the arrangement disclosed by McMahon et al., steam and hydrocarbon liquid are fed cocurrently through the nozzle arrangement.

This is similar to the device disclosed by Snyder in which water and hydrocarbon liquid are fed co-currently. A concentric nozzle is located at the center of the standpipe reactor, and an annular stream of catalyst particles surrounds the nozzle.

Bartholic U.S. Patent No. 4
．． No. 097,243 discloses a hydrocarbon feed distribution system in which a central nozzle and a plurality of peripheral diverging nozzles are fed by a diverging conical header. This feed distribution device or header is located in the center of the standpipe reactor, with the catalyst stream surrounding the nozzle all around.

Flyback (FrybaCk) U.S. Patent No. 3.8
No. 48,811 discloses a fluid discharge nozzle for injecting a hydrocarbon feed into a standpipe reactor in a plurality of separate concentric streams. A plurality of circumferentially spaced holes extend outwardly relative to the direction of flow through the nozzle and act as a pair of frusto-conical members aligned 91 exactly in the direction of flow. One of the frusto-conical members has an additional opening so that the feed is generally sprayed from a number of nozzles all outwardly and upwardly into the standpipe. The nozzle is located in the center of the standpipe reactor and comes into contact with the catalyst flowing down onto the nozzle, and the water vapor comes into contact with the catalyst around the nozzle as it flows upward.

SUMMARY OF THE INVENTION As particularly distinguished from the nozzles for supplying hydrocarbon fluids to standpipes described in the aforementioned patent specification, a particular object of the present invention is to reduce the two-phase pressure drop, water vapor or Directing the flow of the feed by using substantially all of the hydrodynamic energy of the hydrocarbon feed within a single flow path, without co-current passage through the nozzle or multiple flow passages. The goal is to ensure that the liquid is dispersed into small droplets of mist size. Due to the size of such small droplets.

Almost instantaneous vaporization of liquid hydrocarbon droplets by hot catalyst particles in the standpipe is achieved, so that middle distillates, i.e. hydrocarbon liquids with low boiling points, are mainly favored due to the interaction between the catalyst and the hydrocarbons. A gas-phase catalytic reaction occurs that can be obtained as follows. In accordance with the present invention, it has been discovered that a single feed stream can be misted by directing the liquid stream through deflection vanes into a single full flow centrifugal or helical acceleration chamber. The end of the chamber is provided with an orifice which feeds liquid hydrocarbon directly into the catalyst stream in the standpipe reactor and which has a substantially smaller diameter than the chamber. are doing. Such a centrifugal chamber and orifice arrangement is particularly effective in dispersing the hydrocarbon feed into small droplets of sonic mist size. To further enhance the diffusion and spray angle of the misted particles into the catalyst, the surface of the orifice opening $1'r is made substantially equal to the opening area of the throat of the vane in which the helical flow is formed. Said openings have a substantially smaller area than the respective cross-sectional area of the feed flow line and the centrifugal or helical acceleration chamber supplying such a liquid flow. The vane member, which rotates the feed stream in a helical or centrifugal manner before ejecting it from the narrowed area orifice, is at a shallow angle (sha, 11) with respect to the flow axis.
ow angle), thereby minimizing the pressure drop that occurs in the supply line and across the orifice.

In a preferred form, the cylindrical or helical swirl chamber and outlet orifice are arranged axially of the hydrocarbon feed line, thereby minimizing pressure drop in the fluid flowing through the nozzle. The orifice exit throat should be substantially shorter than the length of the centrifugal swirl chamber. By doing so, substantially all of the hydrodynamic energy in the flowing fluid is converted into a dispersion or mist of droplets.

The large opening area through the single swirl vane and exit orifice is advantageous compared to prior art nozzle designs. This is because the larger area reduces the problem of nozzle blockage, especially for nozzles recessed into the wall of a standpipe reactor, by avoiding wear and direct heating by the hot catalyst flowing over the orifice. This is because the misting or dispersed flow pattern of the feed delivered from the feedstock is not disturbed. In a preferred form of the invention.

A plurality of nozzles are distributed at equal intervals around the transition section of the standpipe reactor where the catalyst stream changes to a mixture of catalyst and hydrocarbon material.

Objects and advantages of the invention other than those stated above will become apparent from the following detailed description, taken in conjunction with the drawings, which form an integral part of the specification.

PREFERRED EMBODIMENTS OF THE INVENTION The drawings, particularly FIG. 1, show a fluid catalytic cracking apparatus to which the present invention is applied. The system generally consists of a standpipe reactor 1o in which heated catalyst supplied from a regenerator 12 is reacted with liquid hydrocarbons. The catalyst flows from the regenerator 12 through the U'$ pipe 14 to the pipe 1o. The catalyst is partially fluidized within the U-tube 14 by gas, preferably steam, supplied by a series of nozzle rings 13 along the length of the U-tube.

The catalyst fed by gravity through the intake port 15 in the regenerator 12 is entrained by water vapor, becomes partially fluidized, and is conveyed to the standpipe 1o.

A flow of hydrocarbon liquid is supplied to standpipe 1o by line 21 under control by valve 22.

As shown in FIG. 2, the line 21 is an annular header 23.
The supply nozzle 2o is connected to the ring of the supply nozzle 2o. Since the diameter of the catalyst particles is on the order of 20-120μ, the liquid feed from line 21 and header 23 should be minimized to achieve intimate contact of small droplets of liquid and substantial VC instantaneous vaporization. Uniform distribution and proper droplet size are important. The above conditions are essential since the gas phase contact reaction time to produce the desired low boiling range liquid by contact between the thermal catalyst particles and the hydrocarbon droplets is on the order of 1 to 10 seconds. Optimum catalytic reactions yielding mid-boiling hydrocarbons rather than gas or coke require 1 to 6 seconds;
And reaction times of about 1 second are often even more suitable.

The virtually instantaneous reaction of the small droplets of misted hydrocarbons with the heated catalyst particles generates a large volume of hydrocarbon vapor that initially fluidizes the mixture into reactor 10. immediately into separation tank 2.
It is discharged and separated within 4. The reacted hydrocarbon vapors and catalyst are assigned to the assignee of this invention. Co-pending U.S. Patent Application No. 238.380 (dated February 26, 1981).

No. 335,458 (dated December 29, 1982) and No. 363,946 (1-Dated June 31, 1982)
Separation occurs in the upper part of the tank 24 by the method described in each specification. The disclosures in the specification of the above-mentioned application regarding the general structure and arrangement of a suitable fluid catalytic cracking system to which the present invention can be applied, and in particular the misted bed feed nozzle system that is the subject of the claims of the present invention, are as follows: It should be referred to as part of the book. As described in the above specifications, the catalyst is discharged or discharged from the standpipe 10 and is separated from the steam by the action of inertia and gravity. The spent catalyst is recovered in a storage section 32 attached to or in the lower part of the vessel 24. The generated vapor is collected at the top and condensed in a distillation column (not shown).

The catalyst recovered in the separation process contains a certain amount of residual hydrocarbons deposited on the spent catalyst in the form of coke, which is carbon in nature. All spent catalyst containing such carbon or coke is passed through the stripper element 32 to the regenerator 12.
Return to. Removal of residual hydrocarbon vapors from the spent catalyst is accomplished within the stripper 32 by supplying steam from line "34 through a feed nozzle at the lower end of the stripper 32. The stripper 32 typically includes a plurality of baffles or The inclusion of a channel (not shown) increases the residence time of the spent catalyst.

Steam is introduced through a series of nozzle tubes 36 along return 8-tube 38 to aid in the passage of the catalyst back to regenerator 12 . Regeneration of the spent catalyst is accomplished by adding oxygen through line 40 to combust and oxidize the spent catalyst supported on grid 42. This imparts heat to the catalyst as it circulates through the system, and the heated catalyst returns from bed 4T to standpipe 10 through intake 15. The resulting off-gas from burning the coke exits the regenerator 12 through a cyclone and flue pipe (not shown).

As previously stated, the present invention provides for vaporizing the liquid hydrocarbon feed in the standpipe reactor 10 as quickly as possible so that the reaction mixture collapses within 1 to 10 seconds, most preferably 1 to 3 seconds. The present invention relates to a method for allowing the essential reaction between the vaporized hydrocarbons and the catalyst to proceed while passing through the standpipe 10 within a certain period of time.

With such short reaction times, it is essential that all of the liquid feed be converted to gas virtually instantaneously to achieve the necessary catalyst-gas phase reaction.

Such reactions decompose heavy hydrocarbon molecules into intermediate boiling point hydrocarbons. To achieve such rapid gasification, the flow pattern of the liquid feed into the fluidized catalyst stream must be such that the droplet size and distribution are consistent at the flow rate and pressure at the appropriate application scale. Must be uniform. Unfortunately, a nozzle that creates a pattern like this is likely to become clogged (due to coke formation from the hot hydrocarbons flowing through the nozzle).
It must be able to be used for long periods of time without mechanical wear (due to the abrasive action of the fluidized catalyst particles).

Although the use of steam or water as the primary dispersant fluid to atomize a hydrocarbon feed stream has previously been proposed, the present invention allows for the addition of steam. I have discovered that excellent results can be obtained even without it. In the present invention, a nozzle with a single swirling chamber is used. The chamber/bar is positioned between a full-flow liquid supply line and a narrowed area orifice formed at the outlet end of the swirling chamber to act as a helical or centrifugal acceleration socket. do. To this end, the diameter of swirl chamber 51 is substantially the same as the full inner diameter of flow nozzle 20, as shown in FIG.

The nozzle 20 connects the reactor standpipe 10 at the transition section 17.
The wall 11 and the insulation-wear layer (
1nsulation-ablation 1ayer
) It is desirable that it is recessed by the thickness of 19 mm. As shown in the figure, by doing so, a dispersion pattern in the flow path of the catalyst in the transition section 17 is established.
The liquid flow passing through the orifice 54 can remain at full flow without being dispersed.

The pitch of vanes 53 and the dimensions and length of chamber 51 relative to the diameter and depth or length of orifice 54 are such that the angle of dispersion from nozzle 20 is adjusted so that the dispersion pattern produces appropriately sized droplets. , and the dispersion is selected to occur at some distance from the orifice. With this method, the nozzle including the orifice end is quadrupled in the side wall of the reactor standpipe, so that the small droplets do not come into contact with the side wall of the standpipe 10, but instead interact with the catalyst flowing in the standpipe 10. come into contact.

It is also important to utilize substantially all of the hydrodynamic energy from the hydrocarbon feed through the nozzle 20 to impart swirl or centrifugal action to the feed. By doing so, a straight cylindrical stream having substantially the same diameter as the orifice is formed for a short distance, such as 1 to 2 inches, and then a wide-angle cone of small droplets is formed, as schematically shown in FIG. 1. A desired pattern in which the flow is completely dispersed in the play is obtained. 3. In order to obtain such a pattern of flow, a pair of deflection vanes 53 are inserted into the axis of the flow from the nozzle 20, and , arranged at an angle. The blades 53, which cause the flowing liquid to rotate or spiral, create this tight seven-fold turn. These vanes have a pitch of 15° to 45° relative to the feed line and the axis of chamber 51. The pitch angle is 2
Preferably it is between 5° and 35°, most preferably about 60°.

Since the blades 53 are angled in this way, the total area of the two flows can be made substantially equal to the total flow area of the surface ffff1 exiting lower orifice 54. This allows the full pressure of the supply line to be applied to the rotation of the flow within the chamber 51, and then the liquid can be discharged in the desired pattern.

As shown, the swirl or centrifugal action is diagonal and circular with respect to the direction of flow, resulting in a complete rotation by the entire flow through the nozzle before exiting the narrowed throat of orifice 54. . In the diagram, orifice 54
Although shown as a single circular or cylindrical opening, the opening may have a variety of other shapes, such as serrations in the cylindrical surface 55 of the end wall 56. As illustrated, a.
In addition, the length of the surface 55 is sufficient to form a solid flow over a short distance from the orifice 54. Such a distance allows the nozzle to be recessed into the sidewall of the standpipe 10, including the corrosion-resistant coating, without unnecessarily interfering with the formation of a wide-angle conical dispersion pattern. In practice, the angle A at the tip of such a conical or parabolic region should exceed 90', preferably about 120° as shown in FIG.

As shown in FIG. 2, the nozzles 2o can be distributed at equal intervals around the standpipe 1°. The number of nozzles varies depending on the diameter of the standpipe and the flow rate of the catalyst through it, but can range from 1 or 2 to as many as 1, for example 6 as shown in Figure 2.
or 12 to 15 flJ:v may also be a large number.

As shown in the figure, the angle of the nozzle axis is between 20° and 70”, and more preferably 30” with respect to the axis of the standpipe reactor.
° to 50°, thereby facilitating the dispersion of liquid particles in the direction of flow of the catalyst-hydrocarbon mixture.

In the present invention, although the entire feed is intended to be a hydrocarbon liquid, steam is added directly to the feed liquid in order to reduce the partial pressure of the hydrocarbon liquid after it is fed into the standpipe 10. It is also intended to be added. However, it is essential that such water vapor and hydrocarbon be mixed together before the fluid is introduced into the nozzle 20 and that the mixture be rotated together in the chamber 51 and discharged from the orifice 54. . By doing so, the pressure drop during passage through the nozzle is kept to a minimum and the mixture does not significantly reduce the full 70- under the highest effective hydrodynamic pressure and the orifice 5
After the stream from 4 is dispersed, it can be turned into small droplets with the desired particle size. In this way, the desired mist is formed in the standpipe, so that such droplets that come into contact with the heated catalyst particles are immediately and completely vaporized.

As previously mentioned, the use of steam for the initial reaction of the hydrocarbon fluid with the catalyst is generally undesirable in fluid catalytic cracking. The reason is,#! This is because steam along with the steam recovered in 1I24 must pass through the top of the column and be treated with the condensed hydrocarbon products. To such a condensation! :j) Sour water installation problems arise because water-soluble substances in the condensate, especially oxides of sulfur, nitrogen and carbon, lead to problems in disposing of acidic water. Additionally, the need to recover and dispose of the "sour water" in the condensate directly reduces the efficiency of the conversion process.

This results in higher operating costs for the system.

In the present invention, it is contemplated that the catalyst particles will be heated to a temperature of 1000° to 1400'F, preferably about 1200° to 1 soo,'F+. The maximum is 15,000F. Although almost instantaneous misting and vaporization can be produced in the system of the present invention at higher temperatures, commercial catalytic cracking systems capable of operation at such high temperatures are not yet common. Nevertheless, the present invention is particularly suited for such high temperature operations because, generally speaking, a full 70-liter of hydrocarbon fluid that would normally be subjected to coking conditions is protected within the nozzle. It is from.

In order to keep the flow rate through the nozzle high, coking should be particularly avoided in this way. Therefore, do you use a water vapor shroud in the ambient atmosphere?

The conventional coking avoidance by steam all-centered or vice versa is solved by the nozzle operation of the present invention which disperses the hydrocarbon feed into small droplets in the form of a sonic mist.

Typical catalysts in new forms of fluid catalytic cracking are:
It consists of a combination of a crystalline substance such as a molecular sieve and an amorphous substance. The main components of this type of decomposable catalyst are silica and alumina, and the silica contains alumina in a weight ratio of about 10 to 60%.

Determination elements in various combinations can also be included. Silica-magnesia and other mixed oxide catalysts can also be used. The catalyst used may contain particles having a wide range of free settling velocities. Commercially available cracking catalyst powder SONG has a particle size distribution of 60-90% by weight within the range of 20-120μ.

A particular advantage of fluid catalytic cracking is that a wide variety of hydrocarbon feedstocks can be purified in this type of process.

These feedstocks include straight run petroleum fractions, petroleum kettle residues, deasphalted oils, hydrocarbon oils and mixtures thereof. Other petroleum hydrocarbon fractions.

That is, % boiling points of 600° F. and above can be advantageously converted to lower boiling point, more valuable hydrocarbon products. In such reactions, the feedstock temperature is generally from ambient to 650°F or 400°F'. Although it is possible to sonicize the feed prior to discharge into the stream of regenerated hot catalyst particles flowing through the standpipe reactor, it is economically advantageous to It is preferable to mainly vaporize. Although a wide range of catalyst to oil feed weight ratios may be used, the catalyst to oil feed weight ratio may range from about 2:1 to about 2:1.
0:1 and a hydrocarbon-catalyst contact time of 1 to about 10 seconds, most preferably a contact time of 1 to 6 seconds.

Why is the arrangement of a cylindrical swirling chamber according to the invention and an orifice having a smaller diameter and shorter throat than the chamber so effective in vaporizing the feed to the desired nozzle? , I completely understand the reason. However, the misting effect by the nozzle is achieved by the fluid changing from an axial flow to an annular or centrifugal flow while passing through the passage of the rotating vanes, which has a low pressure drop and a flow area approximately equal to the area of the orifice. It is considered that Thus, the entire spray that is delivered from the swirling chambers 77 through relatively short orifices rapidly constitutes a short cylindrical flow section;
The flow part spreads out into a large conical part. This putter 7 is not only effective for the rapid conversion of feed into gas from suitably sized small droplets by a catalyst;
Most importantly, the nozzle can be recessed into the side wall of the standpipe, thereby also preventing catalyst wear and direct heating of the nozzle by the hot catalyst.

As the feed rapidly expands into finely divided particles in a wide-angle conical pattern, contact between the hot droplets and the hot catalyst results in highly turbulent flow with the production of large amounts of hydrocarbon vapor. A gas flow occurs. The flow from the nozzle orifice flows into the catalyst stream from the U-shaped pipe 14 to the standpipe 1.
It is desirable to perform this at a point where the area becomes large and the flow of the catalyst becomes somewhat slow due to the transition to zero. The transition portion 17 provides a region of increasing cross-sectional area,
The steam generated from the reaction of the hydrocarbon with the high temperature catalyst helps to rapidly accelerate the feed/catalyst mixture.

It is not completely understood why the desired hydrocarbon expands so rapidly and more completely as a gas. However, a commercial fluid catalytic cracking system using a conventional nozzle S which is not engineered to obtain a mist spray and a nozzle for vaporizing the feed according to the present invention; The comparison is particularly moving. Such changes in hydrocarbon fluid yield from the improved hydrocracking system are shown in the following table.

Table 1 Reactor temperature for conventional (old style) nozzle and mist supply nozzle, P 953'955'
-18 regenerator temperature, 'F 1240
1235-5 catalyst/oil
6,0 5.9 -0.1 Conversion rate, LV% 430-OF' 71.9 72.6
+0.7650-'F 89,6
91.3 +1.7 Yield c2-1% by weight 2.1 1.
8 -0.303''', LV% 7.
1 6.5 -0.6 TeC3, LV'fo
9-2 8.2 1. DC4″″,
LV% 7.5. 7.3 -0
．． 2CC,, LV% 15.6 12.8
-0.805~460°F, LV% 60.
8 63.5 +2.7430%-650°
F, LV% 17.8 18.7 +0.
9650°F+, LV% 10.4 8.7
-1.7 coke, wt% 4.0
3.9'-0,1 By using the nozzle according to the present invention, hydrocarbons having a carbon number of 4 or less,
It will be apparent from Table 1 that, for example, butane, propane, or ethane are significantly reduced, while hydrocarbons in the range from C5 to those having boiling points of about 650° F. are substantially increased. It will be seen that there is also a decrease in the production of heavier hydrocarbons with a boiling point of 650° F., which is indicative of shrinkage, increased coke, or coking of the catalyst. Based on the above comparison and assuming full operation of a commercial plant, the increase in value of the desired product obtained using the nozzle arrangement according to the present invention is calculated at a rate of 925 cents per gallon per day a? This results in a profit of $2,500. For one year, the net gain in value of the product is 750
．． 000~900.0 () [1 dollar/year.

Although specific aspects of the invention have been fully described, those skilled in the art will appreciate that various modifications and changes can be made to the invention based on the operating principle and structure disclosed above without departing from the spirit of the invention. It will be clear that modifications can be made. All such changes and modifications that fall within the scope of the following claims are intended to be included within the scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a front view of the lower part of a fluid catalytic cracking system to which the feed nozzle system of the present invention is applied, in which a standpipe reactor to which heated catalyst is supplied from a regenerator and a used catalyst are separated. The return line flowing from the tank back to the regenerator is schematically shown. FIG. 2 is a cross-sectional view taken in the direction of arrows 2--2 in FIG. 1, showing the arrangement of a plurality of supply nozzles constructed in accordance with the present invention. Such a mechanism directs the hydrocarbon feed from a circular header to a plurality of mist substitution nozzles distributed around the standpipe reactor. FIG. 6 shows arrow 6 for one of the nozzles shown in FIG.
It is a sectional view in the direction of ~B. This nozzle is constructed in accordance with the present invention to ensure that a full flow of hydrocarbons is delivered as a mist into the standpipe reactor from within the sidewall of the fluidized catalyst stream line. FIG. 4 is a sectional view taken in the direction of arrows 4 to 4 in FIG. 6, particularly showing the blade member. These vane members, when the hydrocarbon feed enters,
The feed stream is subjected to a centrifugal or helical motion that directs the feed directly to the catalyst through an oriSwiss having a reduced diameter at the tip of the nozzle. In the figure, 10... Standpipe reactor 112... Catalyst regeneration device, 13 and 36... Nozzle ring% 14 and 38.
... U-shaped pipe, 15 ... Regenerated catalyst intake port, 17 ... Transition part. 20... Raw material supply nozzle, 23... Header, 24
...Separation tank, 32... Stripper, 51... Rotating (centrifugal) chamber, 53... Vane member, 54...
・Orifice. Agent Akira Asamura

Claims (1)

[Claims] (1) Circulating a heated catalyst in a standpipe reactor,
In a fluid catalytic hydrocarbon cracking system in which the viscosity of a liquid hydrocarbon feed is improved by contacting the feed with or without water or steam, the liquid feed is first rotated centrifugally about the axis of flow of the liquid feed. The liquid feed metal is introduced into the reactor so as to contact the heated catalyst flowing through the standpipe reactor by adding a total by means of a flow of liquid through a cylindrical chamber provided in at least one conduit supplying said However, I will send out the flow. The orifice has a diameter that is smaller than the diameter of the chamber and a throat that is substantially shorter than the length of the chamber), so that the hydrodynamic pressure of the feed flowing through the feed line is lower than that of the feed. into a cylindrical stream exiting from an orifice in an opening in the reactor side wall, and then a uniform mist stream of droplets over a uniform conical volume within the standpipe reactor. A fluid catalytic hydrocarbon cracking system comprising: dispersing and contacting the heated catalyst particles. (2) the liquid feed is pumped from a plurality of uniformly distributed locations around the transition between the catalyst stream and the hydrocarbon-catalyst mixture stream in the standpipe reactor; , a fluid catalytic hydrocarbon cracking system according to claim (1). (3) In fluid catalytic hydrocarbon processing systems, increasing the initial yield of monocracked hydrocarbon products by shortening the residence time of the hydrocarbon liquid over the heated catalyst, as well as increasing the initial yield of the monocracked hydrocarbon product through secondary cracking and initial reaction with the catalyst. In a method for reducing coke deposition due to residual hydrocarbons adhering to a catalyst after contact. Contacting a hydrocarbon feed in a uniform spray of liquid particles with a stream of heated catalyst particles for hydrocarbon cracking, the hydrocarbon fluid feed line and the flow of a standpipe reactor within the processing system. The liquid particles are ablated by positioning a nozzle having a centrifugal acceleration chamber between the conduit and the chamber, the chamber being coaxial with the conduit constituting the supply line and within the end wall of the chamber. and having an outlet orifice having a smaller diameter than the chamber, the outlet orifice being disposed inside a side wall of the reactor standpipe, and the flow path of the orifice having a diameter smaller than the area of the chamber. The nozzle also has a substantially small area, the nozzle including at least one pair of vanes between the hydrocarbon supply line and the centrifugal chamber, the total area of the flow path to the vanes being equal to the area of the orifice. substantially equal to , thereby allowing the fluid feed to be fed as a solid stream through said sidewall,
To have a pattern dispersed in a wide-angle conical volume for contact as a mist of particles with the heated catalyst.
A process as described above, characterized in that the production of hydrocarbon fluids in the low boiling range is increased, while the conversion of the hydrocarbon fluids into gas and coke is reduced. (4) In an apparatus for improving the reaction rate between a hydrocarbon liquid and a heated fluidized bed catalyst in a fluid catalytic hydrocarbon cracking system, a liquid hydrocarbon is contained in a reactor standpipe of the fluid catalytic hydrocarbon cracking system. at least one nozzle device is disposed for atomizing a feed of the reactor standpipe, the nozzle device being recessed within the wall of the reactor standpipe, and the nozzle device connecting the cylindrical swirl chamber to the liquid hydrocarbon feed conduit. and an exit orifice from the chamber, and a fixed vane member between the supply line and the chamber to prevent centrifugal rotation relative to the flow axis of the orifice and chamber. Applied to said liquid, said outlet orifice is smaller in diameter and substantially shorter in length than said pivot chamber, and said orifice and said chamber both have a full flow rate throughout their entire cylindrical volume. The device as described above, wherein the device is in an open state. (5) A plurality of nozzles are distributed substantially uniformly around the transition section of the reactor. The device according to claim (4). (6) 20' to 70 mm relative to the axis of the standpipe reactor
Device according to claim 4, characterized in that said nozzles are arranged at an angle of .degree. (7) the fixed vane is 1 with respect to the axis of the chamber;
Claim (4) having an angle of 5° to 45°
). 18) The apparatus of claim (7), wherein said angle is between 25" and 65°. (9) The apparatus of claim (7), wherein said angle is between 15" and about 30". The device described.