DE3536717A1 - MULTI-CHAMBER FLUID BED REACTION DEVICE - Google Patents

Description

MITSUBISHI KINZOKU KABUSHIKI KAISHA, TOKYO / JAPAN

Multi-chamber fluidized bed reaction device

The invention relates to a multi-chamber fluidized bed reaction device, their efficiency increased and their simple structure can be realized by the fluidized bed area and the wind box area are divided into more than two chambers and each is subdivided Chamber is fed with reaction gas, its composition, flow rate and temperature can be freely selected are, with a fluidized bed, a moving bed or a fixed bed under regulation in each subdivided chamber the reaction in each chamber and the transfer of particles between the chambers.

A fluidized bed reaction device based on a gas-solid system forms a fluidized bed by fluidizing solid particles with a

Fluidizing gas and carries out the gas-solid reaction by bringing the fluidized particles into contact with get a reaction gas. Such a device is widely used in industrial applications. However, in the above-mentioned device, several different reactions are intended to be continuous are performed, it is necessary to multiply the device. There are two systems for this available, namely a multi-tower system, which has more than two separate devices, and a multi-chamber system, which multiplies the inner area of a single device. The latter system aims to increase its efficiency by multiplying the same reaction by drying and cooling to improve the particles (anonymous, - Chem. Eng. 63, (1956)), but since the system has no function of control of particle reaction and particle transfer, it cannot realize different reactions. On the other hand, the multi-tower system is generally used to carry out various reactions by multiplication used (CD. Harringting et al; Uranium Production Technology, D. Van Nostrand Company, INC P550-501 (1959)). However, since the fluidized bed reaction device is multiplied in the multi-tower system, see above the opportunity for particle transfer between the towers is increased, so that many pipelines for transfer of particles, pumps for transfer and conveyor systems are required. Therefore, the structure of the The device and the operating system not only complex and the design of the device, the manufacture of the Components and the operation of the device are granular

plicated, but the multi-tower system is also regarding detrimental to its cost.

■. The inventors paid attention to the fact that in accordance with the aforementioned multi-chamber system, the reaction efficiency can be improved can, even if the reactions are identical, and they have advocated a multi-chamber fluidized bed reaction apparatus to create that allows different reactions to be carried out and improve the efficiency of the device and the simplification of the operating system by eliminating the aforementioned disadvantages of common ones Multi-chamber systems permitted.

As a result, the inventors found that a Multi-chamber fluidized bed reaction apparatus of the aforementioned type can be obtained by the Regulating conditions for the reaction of the particles and the amount of particle transfer are ensured, thus realizing the present invention.

The invention is based on the object of a multi-chamber fluidized bed reaction device to create, welehe has an improved efficiency. About that In addition, a multi-chamber fluidized bed reaction device is to be created by the invention, which by Simplifying the operating system has a simple structure.

This task is carried out by a multi-chamber fluidized bed

Reaction device solved, which according to the invention is characterized in that there are more than two chambers in which the fluidized bed area and the wind box area of the device is provided with partitions so that each compartment is divided with a Gas-particle separation device is connected and fed with a reaction gas and / or an inert gas is, of which composition, flow rate and temperature are freely selectable, and that in each subdivided Chamber regulating particle formation, gas-particle reaction and the amount of particle transfer a fluidized bed, a moving bed or a fixed bed is formed between the chambers.

In a further embodiment of the invention, in addition to the above-mentioned structure, the construction step add a gas seal of the reaction gas.

As described above, according to the invention the implementation of the various reactions possible by using the fluidized bed area and the wind box area for the supply of a fluidizing gas divided into a multiple chamber and the operating system {Amount of reaction gas, gas temperature, etc.) can be made freely selectable in each chamber, whereupon the training of a fluidized bed, a moving bed or a fixed bed in each chamber is made possible by the height the partition wall appropriately chosen and the regulation of the particle reaction and the particle transfer through Regulation of a flow rate of the feed gas is made easy, the particles formed through

Arranging a gas-particle separator in each chamber can be effectively recovered.

The invention will then be explained with reference to the drawings explained in more detail. Show it:

Fig. 1 is a schematic elevation

a preferred embodiment of a multi-chamber fluidized bed reaction device according to the invention

processing in which uranium oxide is converted into UF;

FIG. 2 is a schematic elevation of FIG

usual multi-tower arrangement

according to the device of FIG. 1;

Fig. 3 (a) is a schematic elevation view of the

Fluidized bed reaction device, in which the partition in appendix

ge is arranged with the base surface of the fluidized bed;

Fig. 3 (b) is a schematic elevation view of the

Fluidized bed reaction device,

in which the partition is arranged over a gap that extends over the base surface of the Fluidized bed opens; 30th

Fig. 3 (c) is a schematic elevation view of the

Fluidized bed reaction device which unites the partition wall of Fig. 3 (a) and that of Fig. 3 (b);
5

Figure 4 is a schematic elevation of a

v.'other embodiment of the invention, according to which a Fluidized bed reaction device to a connecting pipe

is closed in view of the difficult integration of the reaction device into a unified System;

5 (a), (b), (c), (d) are schematic top views of a

Arrangement of the device, the great freedom in the arrangement the inventive device illustrated;

Fig. 6 is a schematic plan view of a

Fluidized bed reaction device in block construction that extends both horizontally and vertically

lets go further; and

Fig. 7 is a schematic plan view of a

Fluidized bed reaction device with recirculation, in which the

Particles are circulated again.

The invention will now be explained in detail, whereby, for example, the multi-chamber device according to the invention is compared with the customary multi-tower system for an application in which uranium oxide is converted into UF ₆ and a multi-chamber device in block construction was selected as the exemplary embodiment of the reaction device according to the invention .

According to FIG. 1, the chambers 1-14 represent a multi-chamber fluidized bed area represent (in some cases part of which becomes a moving bed or a fixed bed), the chambers 1a-14a illustrate the wind box area for supplying fluidizing gas to the chambers 1-14, respectively Nozzles 1b-14b supply the chambers 1-14 with fluidizing gas.

Of the chambers 1-14, the chambers 1-2 have the task of U ₀ O ₀ or UO .. to UO-, to reduce, and the chambers 3-6 are used for cooling and storing the particles, for gas sealing and for regulating the Particle transfers. Chambers 7-8 have the task of UO2 in UF. to convert, and the chambers 9-12 serve to cool and store particles, to seal off gas and to regulate the transfer of particles. The chambers 13-14 are used to convert UF ₄ into UF. The raw material U ₃ Og or UO., Is fed via a raw material feed line 15 to the chamber 1, in which U ₃ O ₈ or UO ₃ by means of hydrogen gas, which is contained in the fluidizing gas fed via the nozzle 16 and the wind box 1a, is reduced to UO _. If in chamber 1 the U0 ~ -

Particles that form the fluidized bed, the height of the Enlarge the fluidized bed according to the amount of raw material supplied from a uranium compound, so you get from chamber 1 to chamber 2 mainly under the pressure of the fluidized bed through the lower gap in the partition.

In chamber 2, remaining U_0 _o or U0_ in the unconverted state of chamber 1 is almost completely converted into UO- with hydrogen gas. The hydrogen gas for reduction is contained in the fluidizing gas supplied via the wind box 3a and the nozzle 3b emits the hydrogen gas remaining under the RO “particles and at the same time prevents hydrogen gas from entering the subsequent chamber by means of a gas seal. The chamber 4 and the chamber 5 serve to cool and store the particles, nitrogen gas being supplied via the nozzle 4b, the wind box 4a, as well as 5a and the nozzle 5b. The fluidized bed is formed in the chamber 4, while a fluidized bed or moving bed is generated in the chamber 5. The chamber 5 and the chamber 6 also have the task of regulating the transfer of particles. The amount of transfer of the particles is regulated by the amount of gas that is supplied to the chamber 5 and the chamber 6.

By regulating the amount of nitrogen gas supplied to the chamber 6, the height of the fluidized bed changes in chamber 6 as well as the amount of particles that flows on to chamber 7A. The amount of particles that passes from the chamber 5 into the chamber 6, is through

the relation of the bed height in the chamber 5, the amount of the nitrogen gas supplied to the chamber 5 and the amount of the nitrogen gas supplied to the chamber 6 are determined. Finally, when the amount of nitrogen gas supplied to the chamber 6 is caused to fall below a limit value of the flow rate (speed at the initial fluidization), the fluidization is stopped to form a fixed bed in the chamber 6 and the transfer of particles to the chamber 7A becomes stopped. As a result, the chamber 5 and the chamber 6 are caused to perform a function of particle storage and chamber 6 takes on the function of a gas seal. As in chamber 7, HF gas is used, the nitrogen gas supplied to chamber 6 preventing the HF gas from entering the adjacent chambers. In chambers 7A, 7B, 7C and in chamber 8, UO ₂ becomes UF with HF gas. converted. HF gas is supplied as part of the fluidizing gas via 7Ab, 7Aa and 8b, 8a. The complete conversion of UO ₂ to UF. takes place somewhat slowly and careful monitoring of the operating conditions is required, it being known that, according to the reaction of the initial phase and that of the final phase, a change in the reaction conditions is effective in order to effectively promote the progress of the reaction. Based on this point, the fluidized bed area is designed as a multi-area in this reaction area in order to change the operating conditions alternately in each area and the chamber is divided into 7A, 7B, 7C and 8, so that the temperature of each chamber and the composition of the supplied HF gas can be freely chosen. Chambers 9-12 have similar ones

Function like the chambers 3-6 and the HF gas remaining in the chamber 9 under the particles is expelled and prevented from entering and to chamber 1 by means of a gas seal. The chambers 10 and 11 have the task of cooling and storing the particles and at the same time regulating the particle transfer. Chamber 12 is used for gas sealing against the HF gas used in the chamber 13 or in the chamber 14 also to regulate the particle transfer in connection with chamber 11. In chamber 11 a fluidized bed, a moving bed or a fixed bed is formed, while a fluid bed or a fixed bed is formed in chamber 12 are.

The chambers 13 and 14 have the task of UF. in UFg by means of To convert F "gas, which is supplied as fluidizing gas via 13b, 13a and 14b, 14a. In the UF conversion process it is important to increase the use efficiency of the expensive F gas as much as possible, as this is directly linked to the reduction in production costs. For this purpose it is necessary to use the quantitative Relationship between UF. and the F "gas supplied to the reaction chamber, and consequently the The task of quantitative regulation of particle transfer is of considerable importance.

In the chambers 13 and 14, alumina or CaF particles are placed used as a fluidizing medium. The UF. Particles fed to the chamber 13 react with the F - gas when fluidizing with the fluidizing medium to form UF - and unreacted UF. Particles

enter chamber 14. In the chamber 14, the unreacted UF. Particles react again with F ₂ -GaS to form UF, but the unreacted UF remains. partly here to be returned to chamber 13. Thus, UF. Particles are circulated with the fluidization medium between the chamber 13 and the chamber 14 and the degree of utilization of the Fp gas can be _{determined by quantitative changes in the F ~ gas supplied via 13b and 13a and the F 2 ~ gas supplied via 14b, 14a} higher than in the case of a single fluidized bed.

In a gas-particle separation area 16-22, the particles accompanied by the gas from the fluidized bed become the gas separated, and the separation area is divided by particle and gas parts, each divided separation area each equipped with a gas-particle separation filter. The gas-particle separation areas 16 and 17 have a common exhaust pipe, but are separated in chambers 1 and 2 to prevent mixing of particles of chambers 1 and 2 to avoid. The gas-particle separation area 18 is independent because the greater part of the gas consists of nitrogen gas.

In the gas-particle separation regions 19A, 19B and 20, the main component of the gas is HF gas and vapor, however, it is with regard to the difference in the reaction conditions, especially the difference in the HF gas concentration in each chamber, the gas-particle separation area is divided into three sections, in each of which one Post-treatment is possible. The gas-particle separation area

is designed similar to the separation area 18. The gas supplied to the gas-particle separation area 22 is a gas mixture of UF, gas, remaining F _n -GaS and nitrogen

o 2.

fuel gas. The gas mixture is separated in the gas separation area 22 and fed to a cold trap to recover the UF, and to a cleaning reaction line to increase the extent to which the remaining F ₂ gas can be used.

The device according to the invention will now be explained, by comparing their components with those of the conventional device of FIG.

According to FIG. 2, there is a fluidized bed reaction device 30, which _{reduces U 0} O ₀ or UO ₀ to UO _n , as well as fluidized bed reaction devices 38 and 41, each of which U0 ″ to UP. convert and a fluidized bed reaction device <~ r 48, the UF. in UF, - converts. The construction

4 ο

elements 33-36 are each used to cool and store particles, as well as for gas sealing and for Transfer of particles in the gas flow. A feed device 37 is used to supply a fixed amount of particles. The components 39 and 40 each serve to seal off gas and supply a fixed amount of particles and the components 4 3-4 6 are used for cooling and storage of particles, for gas sealing and for the transfer of particles in the gas flow. A feed device 4 7 supplies a fixed amount of UF .. 30b, 38b, 41a, 48b are solid-state gas separation filters of the fluidized bed reaction apparatus. The equivalent of this Components of the known device to those of the

device according to the invention is as follows:

The fluidized bed reaction device 30 of FIG. 2 corresponds to the chambers 1 and 2 of FIG. 1 and the components 33-37 have the same function as the chambers 3 to 6. The fluidized bed reaction devices 38 and 41 correspond to the chamber 7 and the chamber 8 and the components 4 3-47 have the same task as the chambers 9-12. The fluidized bed reaction device corresponds to chambers 13 and 14. The solid-state gas separation filter 30b corresponds to 16 and 17, 35b corresponds to 18, 38b corresponds to 19, 41a corresponds to 20, 45b corresponds to 21 and 48b corresponds to 22. The known fluidized bed reaction devices are all executed in cylinder design. According to FIG. 2, U ₃ Og or UO _{3 , which is fed in through the feed line 31, is converted to UO 2} with HL gas, which is fed in through the line 32 to the fluidized bed reaction device 30. After the formed U0 _? the feed device 33 is fed, it is conveyed further via the feed device 34 and passed through a solid-gas separation device by a nitrogen gas flow fed in at 34a and reaches the feed device 36 for the fluidized bed reaction device 38 the feed device 37 is supplied, reacts in the fluidized bed reaction device 38 with the HF contained in the exhaust gas 41 in order to be partially converted into UF ₄ . The particles then reach the receiving device 3 9 and are fed to the fluidized bed reaction device 41 by the quantitatively effective feed device 4 0, in

which unreacted particles with HF to form UF. react. The components 4 3-4 7 have a similar function to the components 33-37 and serve to supply particles to the fluidized bed reaction device 48. In this UF reacts. with F "gas supplied from pipeline 49 to form UF, and the latter is fed to a system 48a having a cold trap for recovering UF and increasing the level of use of the remaining F ₂ gas.

As previously explained, in the conventional apparatus, each tower is independent and the transfer of particles between the towers occurs due to an energy drop, so with this arrangement the height increases and the required area is larger. Furthermore, the height of a building increases as a result Attachment of the device and the floor area of the same becomes larger, so that for a nuclear facility required ventilation capacity increases. A method is used to reduce the overall height, which the Brings particles into a high position by means of a gas stream, as is the case with the device according to the invention according to FIG. 1 applies, however, a device which with a particle transfer by means of gas flow works, complex, the area occupied becomes larger, and arrangement and operation become more complicated. In such circumstances, increasing the number of towers is not the best solution and improvement the reaction efficiency through a multiple arrangement becomes difficult.

On the other hand, with the device according to the invention due to the substantially horizontal particle transfer, the height of the device be lower and for the Particle transfer is not a special device necessary. Therefore, the device can be extremely simplified. A multiple arrangement for improvement the efficiency of the fluidized bed reaction device can be easily carried out by increasing the number of chambers is increased and further the efficiency of the reaction process can be easily improved by adjusting the operating conditions be carefully changed, as the operating conditions in each chamber can be freely selected.

In the device according to the invention, the multiple arrangement is in the conversion range from UO ₂ to UF. a good example of this.

Finally, there is the device according to the invention mainly from a fluidized bed reaction process, but can - as previously explained alongside the fluidized bed, a moving bed and a fixed bed can easily be realized by changing the amount of gas supplied is changed and the device as a result, for example, has the advantage that it can be used immediately for a process can be used in which an improvement in the efficiency of the reaction is expected, in which a fluidized bed reaction process and a moving bed reaction process are combined with each other.

There are two methods of arranging the partition in each chamber, i.e., a method in which

the partition is arranged in abutment with the base surface of the fluidized bed and the other method in which the partition is arranged over a gap which opens over the base surface of the fluidized bed. 5

In a conventional multi-chamber fluidized bed reaction device according to FIGS. 3 (a) and 3 (b), the partition wall only one of these two types of partitions is used. In the system of Fig. 3 (a), in which the partition placed in abutment with the base surface of the fluidized bed, the problem arises that when rough Particles are present in the particle mixture, these coarse particles remain in the base area of the fluidized bed and do not flow over the partition, as a result of which the fluidized bed is formed on the coarse particle layer results. In the system according to FIG. 3 (b), in which the partition wall is arranged over a gap, that opens above the base of the fluidized bed is not such a problem as that of the firg. 3 (a) present, but the probability of a short circuit of particles between the chambers is greater, which is undesirable for the course of the reaction. In contrast, these problems can be solved by combining the two Systems according to Fig. 3 (c) can be avoided and at the same time the efficiency of the reaction can be increased, since the flow of the particles approximates a piston flow. Furthermore, by connecting this Both systems achieve a combination of the fluidized bed and the moving bed, which is what the known Systems is not possible. In this embodiment, a fluidized bed reaction device is in block

construction presented as a physical unit. However, different types of material are used and it is difficult or uneconomical to bring these into a physical unit or occur as a result extremely different temperatures between the chambers result in unequal thermal expansions, so that there is It is difficult to control the operating conditions, so it becomes difficult to establish a physical unit by connecting several types of reaction devices and these difficulties can be obtained can be avoided without changing the basic idea of the invention.

In the arrangement of Fig. 3 (a), in which the partition is arranged in abutment with the base surface of the FIjessbettes coarse particles mixed in the particles remain in the base layer of the fluidized bed and do not flow over the partition wall, so that there arises a problem that there is a fluidized bed thereon trains. In the arrangement according to Fig. 3 (b), in which the partition wall is arranged over a gap, which opens above the base surface of the fluidized bed becomes such a difficulty as shown in Fig. 3 (a), not generated, but the probability of short-circuiting of particles is greater, which affects the course of the reaction is undesirable.

In contrast, this difficulty can be avoided by combining the two arrangements and at the same time the particle flow approaches a piston flow, whereby the efficiency increases according to FIG. 3 (c)

the response increases. Furthermore, the combination of the two arrangements results in a combination of a fluidized bed and a moving bed, which is not possible with the known arrangement.
5

In this embodiment is a fluidized bed reaction device Shown in block construction as a unified system. However, the arrangement is one unified system difficult or unreasonable with regard to the different types of materials used and a unified system is difficult to realize in view of uneven control of the Operating processes, including thermal expansion as a result of widely differing operating temperatures, so these difficulties can be avoided without departing from the basic idea of the present invention is changed by connecting a plurality of reaction devices by connecting pipelines.

Fig. 4 shows an embodiment of this type. In Fig. 4, separate reaction devices 50-52, which are provided with an expansion option if thermal expansion requires it, shown. Furthermore, the device according to the invention has the advantage that the freedom in the arrangement of the device are extremely large.

Figs. 5 (a), (b), (c), (d) each show an arrangement a fluidized bed reaction device according to the invention in block construction. Furthermore, according to FIG. 6 by using a system in which a block

built-up fluid bed is expanded vertically and horizontally, one process series by horizontal Expansion can be realized and an effortlessly increasing process capacity of the device through their vertical expansion. Thus, the block type fluidized bed reaction apparatus overcome the shortcomings of the known fluidized bed reaction apparatus which are not easily expanded can. According to FIG. 7, in which the chambers 80-83 are close to one another, the device according to the invention can be constructed as a fluidized bed reaction device in a single design.

The present invention realizes the following results by using the foregoing described arrangement.

(1) Move in the device according to the invention the particles move approximately in a horizontal direction, so that the height of the device can be reduced and since no special device is required for conveying the particles, the device in their structure can be simplified.

(2) In the device of the present invention, the device is multiplied by more than two Chambers possible and the operating system of each chamber is freely selectable, so that the reaction efficiency of the Device can be improved by carefully changing the operating system each time.

(3) By gas sealing the reaction gas, its undesirable effects can be avoided and at the same time the yield of particles can be increased.

(4) The freedom in the arrangement of the device is, as FIG. 5 shows, extremely great.

(5) If the arrangement of each chamber is made similar to that of FIG. 7, the device can also be used as a recirculation fluidized bed reaction device which circulates the particles.

(6) When a block type fluidized bed reaction apparatus is used, a variety of methods can be used can be carried out by expanding the device in the horizontal direction and the processing capacity of the device can be increased to a larger scale by expanding the device in the vertical direction Direction is expanded.

(7) In the device according to the invention with two chambers, when UF _{4 is converted} into UF, the amount of F gas supplied to the two chambers can be regulated in each case and, as a result, the F "gas can be used to a greater extent than with a fluidized bed. Reaction device that has only one chamber.

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Claims (5)

HOFFMANN · EITLE &: PARTNER ■ _-.: PATENT- AND LAWYERS PATENTANWÄLTE DIPL.-ING. W. EITLE DR. RER. NAT. K. HOFFMANN DIPL.-ING. W., LEHN DIPL.-ING. K. FÜCHSLE ■ DR. RER. NAT. B. HANSEN · DR. RER. NAT. H -A. BRAUNS DIPL.-ING. K. GORG DIPL.-ING. K. KOHLMANN · RECHTSANWALT A. NETTE * 5 R ^ fi 7 1 4 2 757 / wa MITSUBISHI KINZOKU KABUSHIKI KAISHA, TOKYO / JAPAN Multi-chamber fluidized bed reaction device PATENT CLAIMS 1. Multi-chamber fluidized bed reaction device, characterized in that more exist as two chambers in which the fluidized bed area (1-14) and the wind box area (1a-14a) of the device are provided with partition walls (55), that each subdivided chamber with a gas-particle separator is connected and fed with a reaction gas and / or an inert gas, of which composition, flow rate and temperature are freely selectable, and that in each subdivided Chamber regulating particle formation, gas-particle reaction and the amount of particle transfer a fluidized bed between the chambers ARABELLASTRASSE 4 D-8000 MÜNCHEN 81 TELEPHONE (Όί3 © 3 911087 TELEX 5-29C19 CPATHEJ TELECOPIER S18356 Moving bed or a fixed bed is formed. ■ ■ ":.-_ 2. Multi-chamber fluidized bed reaction device, characterized by more than two chambers, that by dividing the fluidized bed area and the wind box area of the device are formed by means of partition walls, each of which is divided into a chamber with a reaction gas and / or an inert gas is fed whose composition, flow rate and temperature can be freely selected are, and a fluidized bed, a moving bed or a fixed bed is formed in each divided chamber and a gas seal of the reaction gas while regulating the particle formation, the gas-particle reaction and an amount of particle transfer occurs between the chambers. 3. Multi-chamber fluidized bed reaction device according to claim 1 or 2, characterized in that that the partition is in contact with the base of the fluidized bed or is arranged over a gap which opens at the base level of the fluid bed. 4. Multi-chamber fluidized bed reaction device according to claims 1, 2 or 3, characterized in that the moving bed at least is contained in one of the divided chambers. 5. Multi-chamber fluidized bed reaction device according to Claims 1, 2, 3 or 4, characterized in that the multi-chamber fluidized bed reaction device is a block type fluidized bed reaction apparatus.