US3417978A

US3417978A - Method and apparatus for the gasification and combustion of liquid fuel in a fluidized bed

Info

Publication number: US3417978A
Application number: US524338A
Authority: US
Inventors: Suzukawa Yuichi; Kano Hisashi; Miyazaki Haruhiko; Saito Muneki
Original assignee: Ube Industries Ltd
Current assignee: Ube Corp
Priority date: 1965-09-17
Filing date: 1966-02-01
Publication date: 1968-12-24
Anticipated expiration: 1985-12-24
Also published as: GB1146016A; DE1501942A1

Description

4, 1968 YUICHI SUZUKAWA. ET AL 3,417,978

METHOD AND APPARATUS FOR THE GASIFICATION AND COMBUSTION OF LIQUID FUEL IN A FLUIDIZED BED Filed Feb. 1, 1966 exh oust gos exhaust gas 5 I fluidizing gas liquid fuel FIG. I

" 90s jet stream M for selective l4 discharge WW M United States Patent 3,417,978 METHOD AND APPARATUS FOR THE GASIFICA- TION AND COMBUSTION OF LIQUID FUEL IN A FLUIDIZED BED Yuichi Suzukawa, Hisashi Kano, Haruhiko Miyazaki, and Muueki Saito, Yamaguchi-ken, Japan, assignors to Ube Industries, Ltd., Yamaguchi-ken, Japan, a corporation of Japan Filed Feb. 1, 1966, Ser. No. 524,338 Claims priority, application Japan, Sept. 17, 1965, 40/56,596; Dec. 7, 1965, IO/74,784 14 Claims. (Cl. 263-21) ABSTRACT OF THE DISCLOSURE A method and apparatus for the gasification and combustion of liquid fuel in a fluidized bed comprising the injection of at least one gas jet stream directly into the fluidized bed to realize the forced circulation flow of solid particles in the bed.

This invention relates to a method for the gasification and combustion of liquid fuel in fluidized bed and an apparatus therefor.

More particularly, this invention relates to a method and apparatus for the gasification and combustion of liquid fuel in a fluidized bed in which agas jet stream is injected directly into the fluidized bed in addition to the conventional fluidizing gas introduced through a gas distributor. This invention involves also the use of the abovementioned method and apparatus for firing inorganic solid materials by the gasification and combustion of liquid fuel in a fluidized bed.

The gases used are air, oxygen, water vapour, nitrogen, and the other gases, or mixtures thereof. In addition to the ordinary movements of solid particles observed in a conventional fluidized bed, the forced circulation flow of solid particles is realized in the fluidized bed of this invention, because the gas distributor in this invention has a funnel form at least partly around the openings of gas jet stream.

Fluidized bed, as used herein, includes not only a conventional fluidized bed but also the special fluidized bed described above.

The term solid particles means all solid particles held up in the fluidized bed.

The term liquid fuel means fuels, such as oil derived from petroleum refinery; crude oil, gasoline, jet fuel, kerosene, diesel fuel, cracking stock, lube stock, heavy oil, and oils derived from coal or the like, and other combustible organic materials in liquid state.

The term gasification means not only the ordinary gasification of liquid fuel but also the partial gasification of liquid fuel which occurs during the so-called combustion process.

The term combustion means not only the ordinary combustion of liquid fuel but also the partial combustion of liquid fuel which occurs during the so-called gasification.

The term inorganic solid materials means nonmetallic oxides and mixtures thereof, such as limestone, bauxite, dolomite, other ceramic oxides, and cement raw mix, and metallic oxides and mixtures thereof, such as oxides of iron, copper, zinc, tin, nickel, cobalt and manganese.

The term gas jet stream explained in detail.

It should be noted that the present invention is con cerned with the gasification and combustion of liquid fuel and that it is not concerned with solid fuel.

As well known, it is very diflicult to carry out the will be defined later and 3,417,978 Patented Dec. 24, 1968 gasification and combustion of liquid fuel in the conventional fluidized beds on an industrial scale. The present invention has solved this problem and makes it possible to carry out very easily and efliciently the gasification and combustion of liquid fuel in fluidized beds on an industrial scale by using gas jet stream.

In cases where liquid fuel is burned in free space, the fuel is atomized by means of a burner, and gasified so as to form a flame and then burned completely.

On the other hand, in cases where liquid fuel is burned in the conventional fluidized bed, the flame is knocked down by the solid particles and is not formed in the vicinity of burner, because the space density of solid particles in the vicinity of burner is substantially equal to that of solid particles in the other portions of bed. Droplets of the atomized liquid fuel are immediately blown upon solid particles. Thus, the atomizing effect of the burner becomes negligible.

On the contrary, in free space, liquid fuel is gasified on the surface of atomized droplets. Whereas, in fluidized bed, the atomized droplets blown upon solid particles are gasified on the surfaces of liquid fuel films formed on the surfaces of the solid particles. In the latter case, the total contacting surface area between gas and liquid fuel is much smaller than that of atomized droplets in the former case. Accordingly, the rate of gasification of liquid fuel in the latter case is greatly reduced in comparison with the former case. This reduction in the effect of atomization by the burner in the conventional fluidized bed was one of the troubles with the gasification and combustion of liquid fuel in the conventional fluidized bed.

Further, the gasification and combustion of liquid fuel in fluidized bed are affected considerably by the dispersion rate of solid particles in the bed. If liquid fuel is blown uniformly upon the surface of the solid particles in the bed, the total surface area of solid particles being very large, the quantity of liquid fuel blown on each solid particle is very small; and also the sensible heat of solid particles is used effectively for the gasification of liquid fuel. As the result, the gasification and combustion of liquid fuel would easily be carried out.

However, in the conventional fluidized bed, the flow of solid particles in the bed is insuflicient for the gasification and combustion of liquid fuel; the surface area of solid particles in bed is not effectively utilized for this purpose. Solid particles in the vicinity of the burner, upon which droplets of atomized liquid fuel have been blown do not disperse immediately, :and remain in the vicinity of the burner for a while. As a result, the rate of gasification is not parallel to that of dispersion of droplets blown upon the above-said solid particles, forming thick films of liquid fuel on their surfaces. Thus, the total surface area for gasification is reduced further, and accordingly the rate of gasification of liquid fuel is reduced. In bad cases, the whole amount of liquid fuel fed into the bed cannot be held on the surfaces of solid particles in the vicinity of burner, so that some amout of the liquid fuel is deposited at the bottom of the reactor. The fact that the surface area of solid particles is not utilized effectively, is another factor hindering the gasification and combustion of liquid fuel in fluidized beds.

The object of the present invention is to overcome the above mentioned disadvantages originated from the characteristics of the conventional fluidized bed and to enable the gasification and combustion of liquid fuel in fluidized beds on an industrial scale.

Particularly, it is one of the objects of the present invention to provide a method in which the surface area of solid particles throughout a fluidized bed are utilized effectively for carrying out the gasification and combustion of liquid fuel therein.

Another object of the present invention is to provide a method in which the atomizing effect of burner is largely improved by decreasing the space density of solid particles in the vicinity of the burner in comparison wit-h that of solid particles in the other portions of the bed.

A further object of the present invention is to provide a method for firing efliciently inorganic materials on an industrial scale by means of the gasification and combustion of liquid fuel in a fluidized bed.

A further object of the present invention is to provide apparatus suitable for carrying out the said methods.

The present invention provides a method for th gasification and combustion of liquid fuel in fluidized beds, comprising the injection of at least one gas jet stream directly into the fluidized bed to realise the forced circulation flow of solid particles in bed.

Herein, the term gas jet stream means a gas stream which has a gas velocity U; (m./sec.) higher than the superficial velocity U (m./sec.) in the fluidized bed (which is required for maintaining the fluidizing state) and which is injected directly into the fluidized bed and does not pass through a gas distributor.

The amount and speed of the gas jet stream may be varied within a suitable range for maintaining the fluidizing state. This range is determined by the characteristics of the fluidized bed, such as the height of the fluidized bed, the size and its distribution of solid particles; and by the character of the chemical reaction in bed.

In general, the linear velocity of the gas jet stream U (m./sec.) recalculated to the velocity at the temperature of the said stream at the injection opening may be varied in a range of 1.5 to times the superficial velocity U (m./sec.) in the fluidized bed of the whole gas required for maintaining the fluidizing state, which is recalculated to the velocity :at the temperature in the bed; and the volume flow rate of the gas jet stream V (Nm. /hr.) may be varied in a range of 0.05 to 0.95 times the volume flow rate of the whole gas V (Nm. /hr.) required for maintaining the fluidized bed.

The kind of gas jet stream may be either the same as, or different from, the fluidizing gas introduced into the bed through the gas distributor usually a gas containing oxygen, such as air, being used. As a gas jet stream, an inert gas such as nitrogen may be used, but usually air is most suitable.

Now, the present invention provides further a method for the gasification and combustion of liquid fuel in a fluidized bed, comprising the injection of a gas jet stream directly into the fluidized bed from an opening around the injection nozzle for the liquid fuel, realizing the forced circulation flow of solid particles in the bed and simultaneously decreasing the space density of the solid particles in the vicinity of the said injection nozzle of liquid fuel in comparison with that of the solid particles in the other portions of bed. In this method, the rate U U as defined above may be 1.5 to 20, and the ratio V /V as defined above may be 0.05 to 0.95.

Further, the present invention provides a method for firing inorganic solid materials by the gasification and combustion of liquid fuel in a fluidized bed, comprising the injection of gas jet stream from an opening around the injection nozzle for the liquid fuel directly into the fluidized bed to decrease the space density of solid particles in the vicinity of the said injection nozzle in comparison with that of solid particles in the other portions of bed and simultaneously injecting another gas jet stream from at least one position other than the position of the said injection nozzle to realize the forced circulation flow of solid particles in bed. In this method, the ratio U /U as defined above may be 1.5 to 10, and the ratio V /V as defined above may be 0.1 to 0.5.

The significance and effects of the gas jet stream which is the most important part of the present invention will be mentioned in the following.

As above mentioned, in the conventional fluidized bed (in which the whole ga for fl idizi g is in roduced into 4 the fluidized bed by passing through a gas distributor), the solid particles in bed are moved locally and at random by fluidization. In this sense, mixing of solid particles in a fluidized bed has been considered as so-called complete mixing.

As reported, in conventional fluidized beds, only slight downward flow is observed near the wall of the reactor, and the circulation flow of solid particles in the bed can scarcely be observed. The flow of solid particles in conventional fluidized beds is insuflicient for the direct gasification and combustion of liquid fuel in fluidized beds.

On the other hand, a spouted-bed which has used for drying such things as grain, has no gas distributor, and the whole gas is blown into the bed as gas jet stream. Accordingly, the circulation flow of solid particles are observed. However, owing to the absence of a gas distributor, portions are liable to occur at which the movements of solid particles are insufficient locally in the bottom of spouted bed, so that the spouted bed is not used in cases when the agglomeration of solid particles is liable to occur. In addition, as the whole gas is blown into the bed as a gas jet stream, the spouted bed has the disadvantages of the so-called blow-through phenomenon. Thus, spouted beds are not used for the gasification and combustion of liquid fuel.

On the contrary, the method of the present application can realize the forced circulation flow of solid particles not only locally but also through out the bed by using gas jet streams and can further control the flow of solid particles in the bed, as desired, by adjusting the gas jet stream.

Such a procedure for controlling the flow of solid particles could not be realized in the conventional fluidized bed and spouted bed.

Accordingly, the present invention is a useful means for the gasification and combustion of liquid fuel in fluidized bed.

Particularly, in the present invention, a gas jet stream is usually injected into a fluidized bed through the bottom directly, and thereby the flow of solid particles in the bed are relatively good.

As the result, in the said fluidized bed using gas jet stream, the said particles in the bed show the same behavior as that in the conventional fluidized bed (especially local movements of particles near the bottom of bed are as good as that of particles in conventional fluidized bed), and at the same time the forced circulation flow of solid particles throughout bed is also good.

The extent of the forced circulation flow of solid particles in bed can be controlled as desired within a considerably wide range by changing the ratios of U /U and VJ/VO.

For example, in cases of gasification of heavy oil, the ratio of U /U may be varied within a range of 1.5 to 20, and the ratio of V /V may be varied within a range of 0.05 to 0.95. In cases of the firing of inorganic solid materials such as cement clinker, the ratio of U /U may be varied within a range of 1.5 to 10, and the ratio of V /V may be varied within a range of 0.1 to 0.5.

In the field of chemical engineering heretofore, the injection of a gas jet stream directly into fluidized bed without passing through a gas distributor, has been considered to induce an undesirable blow-through phenomenon. For this reason, the use of a gas jet stream in fluidized beds has never been attempted.

The present invention has been established by overcoming the above mentioned theory.

Particularly, the blow-through phenomenon caused by a gas jet stream may occur in a fluidized bed consisting of fine particles. However, as the size of solid particles in bed becomes larger and larger, the momentum of gas jet stream is rapidly absorbed in the fluidized bed and the blow-through phenomenon does not occur.

In accordance with the present invention, in cases when the injection gas velocity of gas jet stream U is much larger than the average terminal Velocity U of solid particles in bed (recalculated to that of solid particles at the temperature in bed), for instance, when U; is approximmately 40 to 50 times U there is a risk of the blowthrough phenomenon. However, if U; is in the order of less than 20 times U the gas jet stream does not induce the blow-through phenomenon in a fluidized bed and moreover one can realize a satisfactory forced circulation flow of solid particles in the bed which is sufiicient for attaining the above purpose.

Thus, according to the present invention, the dispersion of liquid fuel fed into a bed is improved, and further the surface area of solid particles in the bed is utilized effectively. Therefore, the rate of gasification of liquid fuel is increased, and liquid fuel fed into the bed is completely gasified, resulting in the complete combustion of liquid fuel in the presence of sufficient oxygen. The present invention can be applied to various industrial fields of firing nonmetallic and metallic oxides or their mixtures, such as limestone, dolomite, magnesia, cement raw mix, iron oxide, copper oxide, and other oxides, gasification of heavy oil, oil chemical industries, such as fluid catalytic cracking, fluid catalytic reforming, fluid coking, and thermal cracking of naphtha, and also in high load combustion apparatus or the like.

Hereinafter, the apparatus suitable for carrying out the above mentioned method of the present invention will be explained. In order to understand the present invention completely, some embodiments thereof are described by way of examples, with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 is a perpendicular section, diagrammatically showing the outline of an example of apparatus suitable for carrying out the method of the present invention (as an example especially for the gasification and combustion of liquid fuel);

FIG. 2 is a perpendicular section, diagrammatically showing the outline of another example of apparatus suitable for carrying out the method of the present invention (as an example especially for the firing of cement clinker).

FIG. 3 is a horizontal section through AA line of the apparatus of FIG. 2; and

FIG. 4 is a horizontal section of an example of apparatus having plural selective discharge pipes for sintered solid particles.

As shown in FIGURE 1 for carrying out the above mentioned method of the present invention, the present invention provides an apparatus for the gasilication and combustion of liquid fuel in a fluidized bed, comprising: a fluidized reactor 1 having a fluidizing gas inlet 2 in the lower portion and having an exhaust port 3 in the upper portion. A gas distributor 4 is provided in the reactor 1, and a liquid fuel feed pipe 5 pierces the distributor 4 and has a liquid fuel injection nozzle 6 at the-upper end. A

gas jet stream feed pipe 7 pierces the said distributor 4 and has an injection opening 8 of gas jet stream opened around the nozzle 6.

In the illustrated apparatus, plural liquid fuel nozzles 6 and plural injection openings of gas jet stream 8 may be provided.

The gas distributor 4 may preferably be shaped in a funnel form at the bottom at which the injection nozzle 6 and the injection opening of gas jet stream 8 are provided.

An explanation will be given with reference to FIG. 1. Into fluidized bed F in fluidizing reactor 1, which maintains solid particles in fluidizing state above gas distributor 4, a gas jet stream is injected from the injection opening of gas jet stream 8 piercing through the gas distributor 4, and thereby the injection nozzle 6 is surrounded by gas jet injection opening 8. As a result of this arrangement the space density of solid particles in the vicinity of the injection nozzle 6 decreases in comparison with that of solid particles in the other portions of 'the fluidized bed.

Consequently, the liquid fuel is dispersed effectively upon solid particles. Thus, the surface area of solid particles in the bed is utilized effectively and the atomization effect of the liquid fuel is improved.

Further, the other reason for providing gas jet stream injection opening 8 is to realize the flow of solid particles in the bed so as to increase the rate of their dispersion. Thus the availability of the surface area of the solid particles in the bed for gasification and combustion is much improved. Particularly, solid particles in the vicinity of injection nozzle 6 covered with liquid fuel are forcedly dispersed from the vicinity of injection nozzle 6 by the gas jet stream blown upward from the opening around injection nozzle 6 and further dispersed into the other portions in the bed by the forced circulation flow. After the completion of the gasification and combustion of liquid fuel which has been adhered to the surfaces of the solid particles, the said particles return again to the vicinity of injection nozzle of liquid fuel 6.

Thus, using the forced circulation flow of solid particles in the bed by means of a gas jet stream from the opening around the injection nozzle 6, the amount of liquid fuel blown upon each particle is decreased, resulting in an increased rate of the gasification and combustion of the liquid fuel. When no gas jet stream is used around the injection nozzle of liquid fuel, troubles in the burner occur, such as damage by the confliction of solid particles in the bed, blocking phenomena by particles and heat damage, etc.

However, the application of the fluidized reactor of the present invention substantially prevents the confiiction of solid particles at the injection nozzle 6, so that troubles of the burner caused by solid particles in the bed can completely be avoided.

It should be noted that in the fluidized reactor of the present invention, it is preferable to provide an injection nozzle of liquid fuel 6 at the middle portion of the injection opening of gas jet stream 8, but this arrangement is not always necessary.

Though flat gas distributors are usually employed in the conventional fluidized reactor and a flat distributor may be used also in the present invention, a funnel shaped gas distributor around injection opening of gas jet stream 8 as shown in FIG. 1 is preferable for carrying out the method of the present invention.

When gas distributor 4 is flat, solid particles near the said distributor and near the reactor wall are not effectively stirred by the gas jet stream. When the amount of gas jet stream is too large in comparison with the total amount of gas through bed, the gas passing through the distributor 4 is decreased, and the movements of solid particles near the gas distributor 4 and near the reactor wall becomes bad.

The decrease in the movements of the solid particles induces the agglomeration of solid particles or the adhesion of solid particles to the reactor wall or to the gas distributor 4. Accordingly, if required, gas distributor 4 is preferably shaped in a funnel form. This shape of the distributor improves the movement and flow of solid particles in bed.

The apparatus shown in FIG. 1 may be used widely in various industrial fields, such as gasification of heavy oil, oil chemical industries, such as fluid catalytic cracking, fluid catalytic reforming, fluid coking, and thermal cracking of naphtha, and also in the industrial fields requiring use of high load combustion apparatus.

Another apparatus suitable for carrying out the method of the present invention (especially for the firing of inorganic materials) is shown in FIG. 2. This apparatus for firing inorganic solid materials by the gasification and combustion of liquid fuel, comprises a fluidized reactor 1 having a fluidizing gas inlet 2 in the lower portion and having an exhaust port 3 in the upper portion. A gas distributor 4 is provided in the reactor 1, and a feed type of liquid fuel 5 pierces the distributor 4 and has liquid fuel injection nozzle 6 at the upper end. A feed pipe for a gas jet stream 7 pierces the distributor 4 and has an injection opening for gas jet stream 8. A feed pipe 9 pierces the distributor 4 and has an injection opening 10 for solid material. A selective discharge pipe 11 pierces the distributor 4 and has a selective discharge pipe opening 12 for sintered solid particles at the top, and a selective discharge gas inlet 13 in the lower portion.

In the apparatus of FIG. 3, the distributor 4 may preferably be shaped in a funnel form at least in a portion around the discharge pipe opening 12 for sintered solid particles.

Further, as shown in FIG. 3, one selective discharge pipe opening 12 for sintered solid particles may be provided at the center portion of the reactor and around the opening 12 plural injection nozzles for liquid fuel and plural injection openings 10 for solid material may be arranged.

Further, as shown in FIG. 4, plural selective discharge pipe opening 12 for sintered solid particles may be arranged in the reactor, and around each of the openings 12 plural injection nozzles 6 for liquid fuel and plural injection openings 10 for solid material may be arranged.

The firing of cement clinker in a fluidized bed is well known. The present invention provides an improved fluidized reactor suitable for carrying out the firing of cement clinker.

One of the features of the cement clinker reactor in accordance with the present invention is that the fuel oil can be completely bumed in the bed; the particle size distribution of solid particles in the fluidized bed being controlled by charging an amount of seed pellets of raw materials and simultaneously by continuously discharging the relatively coarse sintered clinker particles from bed.

Another feature of the present invention is that the control of particle size distribution and the complete combustion of the fuel oil in the bed are simultaneously carried out and the flow and movements of solid particles in bed, are much improved; so that the agglomeration of solid particles and adhesion of solid particles to the reactor wall or to reactor bottom can be prevented.

In general, in fluidized reactors for cement clinker hitherto known, fuel oil and raw materials are introduced into the bed from the reactor bottom or the reactor side wall by appropriate means. Further, in U.S. Patent 3,022,989 granted Feb. 27, 1962, a selective discharge pipe for sintered particles is located at the center of funnel-shaped unperforated portion provided in the center of a flat gas distributor which is provided at the bottom of the reactor. It was difficult in that apparatus to carry out simultaneously the feed of raw material, combustion of fuel oil and selective discharge of sintered particles of cement clinker, with high efliciency.

The fluidized reactor of cement clinker of the present invention has overcome disadvantages of the conventional fluidized reactor and has solved difficult problems relating to complete combustion of liquid fuel in fluidized bed.

Particularly, it has improved the movements and flows of solid particles in the bed and prevented the agglomeration of solid particles and the adhesion of solid particles to the reactor wall or to the reactor bottom.

The gas jet stream for use in the selective discharge serves also to enhance the effective combustion of the liquid fuel.

In the fluidized reactor for cement clinker, shown in FIG. 2 raw material is fed into the fluidized reactor 1 together with air from the injection opening 10 through feed pipe 9.

Seed pellets of cement raw mix are fed into fluidized reactor 1 from seed feed pipe '16 or from feed pipe 9 together with the raw material.

On the other hand, liquid fuel fed from injection nozzle 6 through the feed pipe 5 of liquid fuel, burns with the assistance of the gas jet stream injected from the injection opening 8 so as to maintain the temperature in the bed required for the firing of cement clinker.

Into the fluidized reactor 1 is introduced fluidizing air from fluidizing gas inlet '2 through gas distributor 4 so as to maintain solid particles in a good fluidizing state.

Solid particles in bed react with the rew material and grow in size, cement clinkering reaction being accomplished simultaneously.

Sintered particles which have grown in size larger than a definite particle size are selectively discharged from bed through selective discharge pipe 11 by means of air introduced from selective discharge gas inlet 13. These large particles are then transferred to the sintered solid particles hopper 14 and discharged as the final product by means of discharge valve 15.

By adjusting the selective discharging air injected from the opening 12, particle size distribution of the solid particles in the bed can be controlled.

Further, in the described fluidized reactor for cement clinker, the funnel-shaped portion of gas distributor 4 is not necessarily extended all over the distributor. This funnel-shaped portion may be confined in a portion of the said distributor, which has selective discharge opening 12 at its center. Injection nozzles 6 for the liquid fuel may be arranged in the flat portion of the distributor outside of the above mentioned funnel-shaped portion. In a large scale fluidized reactor, plural injection openings 10 and injection nozzles 6 may be arranged around selective discharge openings 12.

FIG. 4 is a horizontal section showing an example of apparatus having three selective discharge openings 12 for sintered solid particles. In FIG. 4, the apparatus comprises selective discharge openings 12 for sintered solid particles, injection openings 10 for solid material, injection nozzles 6 for liquid fuel, injection openings 8 for the gas jet stream, and a gas distributor having funnel-shaped toportions 17 which have selective discharge openings 12 for sintered solid particles at the center, and a flat portion 18.

Injection openings 10, injection nozzles 6, and selective discharge openings 12 may be arranged in other ways than that shown in FIG. 4.

One of the features of fluidized reactor shown in FIG. 4 is that the discharge of sintered relatively coarse particles from the bed can be carried out continuously with high efliciency, and thereby the size distribution of solid particles can be controlled simultaneously with carrying out the complete combustion of the liquid fuel.

The arrangement of the selective discharge opening 12 having a funnel-shaped portion at the center of the gas distributor is useful to realize the forced circulation flow of solid particles in the bed so as to prevent the agglomera tion of solid particles and the adhesion of particles to the wall or bottom of the reactor.

Solid particles upon which liquid fuel was blown are forced to disperse from the vicinity of injection nozzle 4 of liquid fuel 4 by the gas jet stream injected from injection opening 8 of the gas jet stream around the liquid fuel injection nozzle 6 and further dispersed throughout the bed by forced circulation flow realized by the gas jet stream for use to discharge selectively the sintered solid particles. As the result, dispersion of liquid fuel in the bed is improved, and the complete combustion of liquid fuel in the bed is thereby accomplished.

The above mentioned fluidized reactor of cement clinker of the present invention gives high quality cement clinker efiiciently and economically.

The following shows examples of the present invention.

EXAMPLE 1 lThis is an example of firing of cement clinker using fuel 01 Conditions of operation Specific combustion load In fluidized bed: 661,000 Kcal./m. hr. Firing temperature: 1450 C. U /U =4.2, (U; at 500 C., U at 1450 C.) V V 0.29 Size of sintered cement clinker: 2 to 4 mm.

The results of mortar tests of the resulting cement were as follows:

(According to ASTM (1109-64, Cl9063, and C204-55.)

Specific surface (Blaine) (sq.cm./ g.) 3250 Tensile strength (psi):

3 days 327 7 days 431 28 days 481 Compressive strength (p.s.i.):

3 days 1920 7 days 3580 28 days 6060 EXAMPLE 2 This is an example of gasification of fuel oil the same as Example 1 (for the purpose of obtaining CO and H gas).

Conditions of operation Temperature of gasification: 1000 to 1200 C. Pressure of gasification: 2000 to 3000 mm. H O UJ/U0:3.3, (UJ at 200 C., U0 at 1100 C.) V V =0.35

Results Quantity of fuel oil: 350 to 370 kg./l000 cu.m.

Gas composition: Percent CO 40 to 45 CO to H 45 to 50 N 1 to 2 CH 0.2 to 0.4 H 5 0.3 to 0.7

EXAMPLE 3 This is an example of combustion in boiler. Fuel: same as Example 1 Conditions of operation Temperature of fluidized bed: 1300 C. U /U =5.0,

(UJ at 500 C., U at 1300 C.) V /V =0.42

Results Specific heat generation rate: 1,260,000 Kcal./cu.m.hr.

What We claim is as follows:

1. An apparatus for the gasification and combustion of liquid fuel in a fluidized bed, comprising a fluidized reactor having a fluidizing gas inlet in the lower portion and having an exhaust port in the upper portion, a gas distributor provided in the said reactor, a feed pipe of liquid fuel piercing said distributor and having an injection nozzle of liquid fuel at the upper end, a feed pipe of gas jet stream piercing said distributor and having an injection opening for a gas jet stream around the said nozzle.

2. An apparatus according to claim 1 for which a plurality of injection nozzles of liquid fuel and a plurality of injection openings for gas jet streams are provided.

3. An apparatus according to claim 1 wherein said gas distributor is shaped in a funnel form at the bottom where said injection nozzle of liquid fuel and said injection opening for the gas jet stream are provided.

4. An apparatus for the firing of inorganic solid materials by the gasification and combustion of liquid fuel in a fluidized bed, comprising a fluidized reactor having a fluidizing gas inlet in the lower portion and an exhaust port in the upper portion, a gas distributor provided in the said reactor, a feed pipe of liquid fuel piercing said distributor and having an injection nozzle of liquid fuel at the upper end, a feed pipe for a gas jet stream piercing said distributor and having an injection opening, a feed pipe for solid material piercing said gas distributor and having an injection opening, and a selective discharge pipe piercing said gas distributor and having a selective discharge opening for sintered solid particles at the top and a gas inlet for selective discharge in the lower portion thereof.

5. An apparatus according to claim 4 wherein said gas distributor is shaped in a funnel form at least in a portion around this discharge opening for the sintered solid particles.

6. An apparatus according to claim 4, wherein one selective discharge opening for sintered solid particles is provided at the center portion of the reactor and around said discharge opening is arranged a plurality of injection nozzles for liquid fuel and a plurality of injection openings for solid material.

7. An apparatus according to claim 4 wherein a plurality of selective discharge openings for sintered solid particles are arranged in the reactor, and around each of the said openings a plurality of injection nozzles for liquid fuel and a plurality of injection openings for solid material are arranged.

8. A method for the gasification and combustion of liquid fuel in a fluidized bed, comprising the injection of at least one gas jet stream through an opening around the injection nozzle of liquid fuel directly into the fluidized bed to realize the forced circulation flow of solid particles in the bed and simultaneously to decrease the space density of solid particles in the vicinity of the said injection nozzle of liquid fuel in comparison with that of solid particles in the other portions of the bed.

9. A method according to claim 8 in which the gas velocity of the fluidized gas jet stream which is recalculated to the velocity at the temperature of the said stream passing through the injection opening is adjusted within a range of 1.5 to 20 times the superficial velocity in the fluidized bed of the whole gas required for maintaining the fluidizing state, which is recalculated to the velocity at the temperature in the bed, and the volume flow rate of the gas jet stream is adjusted within a range of 0.05 to 0.95 times the volume flow rate of the whole gas required for maintaining the fluidized bed.

10. A method for firing inorganic solid materials by the gasification and combustion of liquid fuel in a fluidized bed comprising the injection of a gas jet stream from an opening around the injection nozzle of liquid fuel directly into the fluidized bed to decrease the space density of solid particles in the vicinity of the said injection nozzle of liquid fuel in comparison with that of solid particles in the other portions of the bed, and simultaneously the injection'of another gas jet stream from at least one position other than the opening of said injection nozzle of liquid fuel to realize the forced circulation flow of solid particles in the bed.

11. A method according to claim 10 in which the gas velocity of the gas jet stream, recaluclated to the velocity at the temperature of said stream passing through the injection opening is adjusted Within a range of 1.5 to 10 times the superficial gas velocity in the fluidized bed of the whole gas required for maintaining the fluidized bed which is recalculated to the velocity at the temperature in the bed, and the volume flow rate of gas jet stream is adjusted Within a range of 0.1 to 0.5 times the volume flow rate of the whole gas required for maintaining the fluidizing state.

12. A method for the gasification and combustion of liquid fuel in a fluidized bed comprising the injection of at least one gas jet stream through an injection opening directly into the fluidized bed to realize the forced circulation flow of solid particles in the bed, wherein the velocity of the gas jet stream recalculated to the velocity at the temperature of said stream passing through the injection opening is adjusted within a range of 1.5 to 20 times the superficial velocity in the fluidized bed of the whole gas required for maintaining the fluidized state, which is recalculated to the gas velocity at the temperture in the bed.

13. A method for the gasification and combustion of liquid fuel in a fluidized bed comprising the injection of at least one gas jet stream through an injection opening directly into the fluidized bed to realize the forced circulation flow of solid particles in the bed, wherein the volume flow rate of the gas jet stream is adjusted within a range of 0.05 to 0.95 times the volume flow rate of the whole gas required for maintaining the fluidized bed.

14. A method for the gasification and combustion of liquid fuel in a fluidized bed comprising the injection of at least one gas jet stream through an injection opening directly into the fluidized bed to realize the force circulation flow of solid particles in the bed, wherein the velocity of the gas jet stream recalculated to the velocity at the temperature of said stream passing through the injection opening is adjusted within a range of 1.5 to 20 times the superficial velocity in the fluidized bed of the whole gas required for maintaining the fluidizing state, which is recalculated to the gas velocity at the temperature in the bed and the volume flow rate of the gas jet stream is adjusted within a range of 0.05 to 0.95 times the volume flow rate of the whole gas required for maintaining the fluidized bed.

References Cited UNITED STATES PATENTS 1,513,622 10/ 1924- Manning 26321 2,874,950 2/1959 Pyzel 263-53 3,030,089 4/1962 Johnson 26321 3,085,022 4/1963 Koch 26353 XR CHARLES J. MYHRE, Primary Examiner.

A. D. HERRMANN, Assistant Examiner.

US. Cl. X.R.