FR2571631A1 - MULTI-CHAMBER TYPE FLUID BED REACTION APPARATUS - Google Patents

Abstract

MULTI-CHAMBER TYPE FLUID BED REACTION APPARATUS COMPRISING MORE THAN TWO CHAMBERS, FORMED BY DIVIDING ITS FLUID BED PART AND WIND BOX PART USING PARTITIONS, CHARACTERIZED IN THAT EACH OF THE DIVIDED BEDROOMS IS FIXED TO A GAS-PARTICLE SEPARATOR AND RECEIVES A REACTION GAS AND OR AN INERATED GAS WHICH COMPOSITION, FLOW RATE AND TEMPERATURE MAY BE CHOSEN ARBITRARILY, AND IN EACH OF THE BEDROOMS SO DIVIDED, IS A FLUID BED, A BED A FIXED BED UNDER THE INFLUENCE OF THE ADJUSTMENT OF THE PARTICLE FORMATION, THE GAS-PARTICLE REACTION AND THE QUANTITY OF PARTICLES TRANSFERRED BETWEEN THE ROOMS.

Description

The present invention relates to a fluid bed reaction apparatus for

  multi-chamber type whose efficiency can be improved and simplicity can be obtained by dividing the fluid bed part and the wind box part into more than two chambers, supplying each chamber thus divided with gas reaction whose composition, flow rate and temperature can be chosen arbitrarily, and by forming in each of the divided chambers a fluid bed, a movable bed or a fixed bed under the influence of the adjustment of the

  reaction in each chamber and transferring the particles

them between the rooms.

  A system fluid bed reaction apparatus

  gaseous-solid forms a fluid bed by fluidizing parts

  solid cells with a fluidizing gas and performs a solid gas reaction by bringing the fluidized particles into contact with a reaction gas, and such an apparatus is

  widely used in general industrial field.

  However, when several different reactions are carried out

  continuously killed using the above device,

  it is necessary to multiply the device. In order to multi-

  fold the device, there are two systems, namely a multi-tower system which includes more than two separate devices and a multi-chamber system which multiplies the internal part of a single device. The latter aims to increase its efficiency by multiplying the same reaction, drying and cooling the particles (anonymous; Chem. Eng., 63 116 - 1956 -), but, as it does not have the function of controlling the reaction of the particles and their transfer, it cannot thus carry out different reactions. Furthermore, the multi-turn system is generally used to carry out different reactions by multiplication (C.D. Harrington et al; Uranium Production Technology, D. Van Nostrand Company, INC P550-501-1959-). However, as in the multi-tower system, the fluid bed reaction apparatus is multiplied, the possibility of transferring particles between the towers is then increased, so that it is necessary to use numerous tubes for the transfer particles as well as many transfer pumps and many transfer systems. Therefore, not only the arrangement of the device and its operating system

  become complex and, similarly, the design of the device

  reil, the manufacturing of particles and the operation of the apparatus become complicated, but in addition the system

  multi-turn is disadvantageous in terms of cost.

  The invention stems from the fact that it has been found that according to the multi-chamber system mentioned above, the effect of the reactions can be improved even when these reactions are identical and attempts have been made to create a bed reaction apparatus. multi-type fluid

  chambers, which allows different reactions to be carried out

  while improving the efficiency of the device and simplifying the operating system by overcoming the aforementioned shortcomings of the systems known to

several rooms.

  We thus found that a bed reaction apparatus

  fluid of the multi-chamber type, as mentioned above

  above, can be obtained by setting the conditions for controlling the reaction of the particles as well as the quantity of

particles transferred.

  The object of the present invention is to create a fluid bed reaction apparatus of the multiple type.

  chambers likely to improve the efficiency of the device.

  The present invention also aims to create a

  multi-chamber fluid bed reaction apparatus

  which can provide a simple device structure

  followed by a simplification of the operating system.

  According to the present invention, there is created a fluid bed reaction apparatus of the multi-chamber type comprising more than two chambers formed by dividing its fluid bed part and its wind box part by means of partitions, each of chambers thus divided being fixed to a gas-particle separator and receiving a reaction gas and / or an inert gas whose composition, flow rate and temperature can be chosen arbitrarily, and in each of the chambers thus divided is formed a fluid bed, a moving bed or a fixed bed under the influence of the regulation of particle formation, of the gas particle reaction and

  the amount of particles transferred between the chambers.

  In the present invention, it is possible to add to the above embodiment a sealing operation at the

reaction gas gases.

  In the present invention, as described above, it is possible to obtain the different reactions by dividing the fluid bed part and the wind box part in order to bring a fluidizing gas to a multi-chamber system and to choose arbitrarily the operating system (quantity of reaction gas, gas temperature, etc.) of each chamber to finally form a fluid bed, a movable bed or a fixed bed in each chamber, and this is made possible by choosing the height of the wall suitably and by adjusting the reaction of the particles and the transfer of the particles easily by adjusting the flow rate of the gases supplied, the particles formed being able to be recovered

  efficiently by fixing in each room a separate

gas-particles.

  Various other characteristics of the invention come out

  moreover, try the detailed description which follows.

  Embodiments of the subject of the invention are shown, by way of nonlimiting examples, in

attached drawing.

  Fig. 1 is a schematic elevation according to the invention of a preferred example of a fluid bed reaction apparatus of the multi-chamber type and in which

  uranium oxide is transformed into UF6.

  Fig. 2 is a schematic elevation of an apparatus

  known reil of the type with several turns and which corresponds

to the apparatus of fig. 1.

  Fig. 3 (a) is a schematic elevation of a fluid bed reaction apparatus in which a partition is mounted in contact with the base surface of the fluid bed. Fig. 3 (b) is a schematic elevation of a fluid bed reaction apparatus in which a partition is mounted on an open gap on the surface of

base of the fluid bed.

  Fig. 3 (C) is a schematic elevation of the fluid bed reaction apparatus according to the present invention and which combines the bulkhead of FIG. 3 (a) and the

partition in fig. 3 (b).

  Fig. 4 is a schematic elevation of another example of the present invention in which a fluid bed reaction apparatus is connected by a connecting pipe due to the difficulty of assembling reaction apparatuses

in a unified system.

  Figs. 5 (a), 5 (b), 5 (c) and 5 (d) are all schematic plan views of the arrangement of the apparatus showing the great degree of freedom of the arrangement of the

  apparatus of the present invention.

  Fig. 6 is a schematic plan view of an apparatus

  plate type fluid bed reaction eye which can extend both horizontally and vertically. Fig. 7 is a schematic plan showing a fluid bed reaction apparatus of the recycling type and

which recycles particles.

  The present invention is now explained in detail. By way of example, the apparatus of the multi-chamber type in accordance with the present invention will be compared with the known system with several turns in the case where the uranium oxide is transformed into UF6 and, as

  as an example of the reaction apparatus of the present invention

  tion, we choose a multi-chamber device of the type

with plates.

  In fig. 1, chambers 1 to 14 constitute a part of a fluid bed of the multi-chamber type (in some cases, part of the latter becomes a movable bed or a fixed bed), la to 14a form a part of

  wind box to supply corresponding fluidization gases

  laying respectively on chambers 1 to 14 and lb to 14b are nozzles making it possible to supply a fluidizing gas to chambers 1 to 14. Among chambers 1 to 14, chambers 1 and 2 have the function of reducing U308 or U03 to U02 , and chambers 3 to 6 have the function of cooling and storing the particles to ensure gas tightness and to regulate the transfer of the particles. Chambers 7 and 8 have the function of transforming U02 into UF4, and the

  rooms 9 to 12 have, respectively, the cooling function

  direct and store the particles, ensure gas tightness and regulate the transfer of the particles. The chambers 13 and 14 have the function of transforming UF4 into UF6. The U308 or U03 forming the raw material is applied by a

  pipe 15 for supplying raw materials to a chamber

  bre 1 o U308 or UO3 is reduced to U02 using hydrogen gas contained in the fluidizing gas supplied by nozzle 16 and the wind box la. In bedroom 1,

  that the particles of UO2 forming the fluid bed increase

  tent the height of the bed according to the quantity of raw materials based on uranium compound applied, they transfer from chamber 1 to chamber 2, mainly through the lower interval of the partition under the influence of

bed pressure.

  In room 2, the U308 or UO3 remained in the state

  unreacted in chamber 1 is almost completely trans-

  formed in U02 using hydrogen gas. Hydrogen gas

  allowing the reduction is contained in the fluidizing gas

  tion applied by the windbox 3a and the nozzle 3b and the rest of the fluidizing gas transforms the hydrogen gas remaining among the U02 particles and, at the same time, prevents the hydrogen gas from entering the next chamber the fact that gas tightness is ensured. Chamber 4 and chamber 5 have the function of cooling and storing the particles, and the nitrogen gas is applied by the nozzle 4b, the wind box 4a and the wind box Sa, the nozzle 5b. In chamber 4, a fluid bed is formed, and in chamber 5, a fluid bed or a movable bed is formed. Room 5 and room 6

  also have the function of regulating the transfer of

  ticles. The amount of particles transferred is adjusted by adjusting the amount of gas supplied to

bedroom 5 and bedroom 6.

  By adjusting the amount of nitrogen gas supplied to the chamber 6, the height of the fluid bed of the chamber 6 is changed as well as the amount of the particles which overflow towards the chamber 7A. The amount of particles transferring from chamber 5 to chamber 6 is dictated by the relationship between the height of the bed in chamber 5, the amount of nitrogen gas supplied to chamber 5 and the amount of nitrogen gas supplied to chamber 6. In addition, when the quantity of gaseous nitrogen supplied to chamber 6 is decreased under the influence of a limited flow rate (speed at the level of incipient fluidization), the fluidization is stopped to form a fixed bed in bedroom 6, the

  transfer of particles to chamber 7A is thus stopped.

  Consequently, room 5 and room 6 have the function

  to store particles, chamber 6 having the function of

  tion to ensure gas tightness. As in chamber 7, gaseous HF is used, the gaseous hydrogen supplied to chamber 6, prevents the gaseous HF from entering the neighboring chambers. In chambers 7A, 7B and 7C and chamber 8, the U02 is transformed into UF4 using gaseous HF. HF gas is supplied as part of the fluidizing gas via 7Ab, 7Aa and 8b, 8a. The completion of the reaction from U02 to UF4 is somewhat slow and careful monitoring

  operating conditions is then necessary.

  It is further known that, depending on the reaction of the initial stage and that of the final stage, changes in the reaction conditions can effectively improve the outcome of the reaction. From this point, in this reaction zone, the fluid bed portion is made to several stages in order to modify in turn the operating conditions of each stage, and the chamber is divided into 7A, 7B, 7C and 8 for allow the temperature of each chamber and the composition of the gaseous HF supplied to be chosen arbitrarily. Chambers 9 to 12 have a function similar to that of chambers 3 to 6, and in chamber 9, gaseous HF remaining among the particles is entrained to exit and is prevented from entering and passing through chamber 1 the fact that gas tightness is ensured. The function of chamber 10 and chamber 11 is to cool and store the particles, and

  at the same time that of regulating the transfer of the particles.

  Chamber 12 has a gas tightness function opposite to HF

  gas used in chamber 13 or chamber 14, and also

  that of regulating the transfer of particles in cooperation

  tion with chamber 11. In chamber 11, there is formed a

  fluid bed, a movable bed or a fixed bed, and in the bedroom

  bre 12 a fluid bed or a fixed bed is formed.

  The chamber 13 and the chamber 14 have the function of reacting UF4 to UF6 using F2 gas supplied as fluidizing gas through 13b, 13a and 14b 14a. In the transformation process of UF6, it is important to increase the efficiency of use of the expensive gaseous F2, and this as much as possible because it is

  directly related to lower manufacturing costs.

  For this purpose, it is necessary to control the quantitative relationship between UF4 and F2 gas brought to the reaction chamber. Consequently, the function of quantitatively regulating the transfer of particles presents

of great importance.

  In chamber 13 and in chamber 14, particles of alumina or CaF2 are used as the fluidization medium. The particles of UF4 brought to the chamber 13 react with F2 gas by fluidizing with the fluidization medium to form UF6 and the particles of unreacted UF4 enter the chamber 14. In the chamber 14, the particles of UF4 n unreacted react again with F2 gas to

  form UF6, but UF4 which has not reacted remains partial there-

  ment to be brought back to chamber 13. Thus, between chamber 13 and chamber 14, particles of UF4 circulate with the fluidization medium, and quantitatively changing the gaseous F2 supplied by 13b and 13a and the gaseous F2 brought by 14b, T4a the degree of use of F2 gas can

  be greater than in the case of a single fluid bed.

  16 to 22 represent a gas-particle separation part o the particles accompanied by gas from the fluid bed are separated from the gas, and the separation part is divided into particles and gas, and each part thus divided is mounted with a filter of, gas-particle separation, respectively. The gas-particle separation parts 16 and 17 are common in the waste gas pipeline, but, in chambers 1 and 2, they are separated to avoid mixing of the particles from chambers 1 and 2. The gas separation part 18 -particles is independent of the fact that most of the gas is

nitrogen gas.

  In the gas-particle separation part 19A, 19B and 20, the main constituents of the gas are gaseous HF and water vapor; but, due to differences in the reaction conditions, in particular differences in the concentration of HF gas in each chamber, the gas-particle separation part is divided into three parts in which further processing is made respectively possible. The gas-particle separation part 21 is similar to the separation part 18. The gas introduced into the gas-particle separation part 22 is a gaseous mixture of UF6 gas, F2 gas remaining and nitrogen gas. The gas mixture is separated in the gas separation part 22 and sent to a cold manifold to recover UF6, and in the pipe of a cold reactor to increase the degree of use of the

F2 gas remaining.

  The apparatus of the present invention will now be explained by comparing these components to those of

the apparatus known from FIG. 2.

  of fig. 2 is a fluid bed reaction apparatus which reduces U308 or U03 to U02, 38 and 41 are each a fluid bed reaction apparatus which transforms U02 into UF4, and 48 is a fluid bed reaction apparatus which converts UF4 to UF6 . 33 to 36 each have the function of cooling and storing the particles, ensuring gas tightness and transferring particles by a gas stream. 37 is

  a device allowing to bring a fixed quantity of parti-

  cules. 39 and 40 each have the function of ensuring

  gas-filled and bring in a fixed quantity of particles, and 43 to 46 have the function of cooling and storing particles, ensuring gas tightness and transferring the particles by the gas stream. 47 is a device for delivering a fixed quantity of UF4. 30b, 38b, 41a and 48b constitute a solid-gas separation filter for the fluid bed reaction apparatus. The correspondence of the constituent elements above of the known apparatus with those of the apparatus according to the present invention are as follows. The fluid bed reaction apparatus 30 ′ of la'fig.'2 corresponds to chambers 1 and 2 of FIG. 1, and 33 to 37 have the same function as that of chambers 3 to 6. The fluid bed reaction apparatus 38 and 41 correspond to chambers 7 and 8, and 43 to 47 have the same function as that of

  chambers 9 to 12. The 48-bed fluid bed reaction apparatus

  corresponds to chambers 13 and 14. As regards the solid-gas separation filter, 30b corresponds to 16 and 17, 35b

  at 18, 38b at 19, 41a at 20, 45b at 21 and 48b at 22, respecti-

  vement. Fluid bed reaction apparatuses of known type are all with cylinders. In fig. 2, U308 or U03 brought in by line 31 is made to react with H2

  gas brought by-32 into the apparatus 30 in order to give UO2.

  After the UO2 formed is received by the receiving hopper

  tion 33, it is transferred by the feed hopper 34, and it is transferred by the stream of nitrogen gas supplied by 34 through the solid-gas separation hopper to reach the feed hopper 36 of the fluid bed reaction 38. A fixed quantity of UO2 supplied by 37 reacts in the apparatus 38 with the HF contained in the gas

  of waste 41 to be partially transformed into UF4.

  The particles are successively received by the hopper of

  reception 39 and sent by a feeding device quan-

  titrant 40 to a fluid bed reaction apparatus 41 in which the unreacted particles then react with HF to transform into UF4. 43-47 have a function similar to that of 33 to 37 and carry out the

  particles to the fluid bed reaction apparatus 48.

  In 48, UF4 reacts with gaseous F2 brought by 49 to give UF6, and UF6 is sent to system 48a containing the cold collector in order to recover UF6 and increase the

  degree of use of the remaining gaseous F2.

  As has been described above, in the known apparatus, since each revolution is independent and the transfer of the particles between them is effected by a decrease in power, the height thus becomes greater as and

  as the layout and the occupied area increase.

  In addition and as a result, the height and the area of a shoemaker receiving these devices becomes more and more

  high and wide, so that the ventilation capacity is

  particular to a nuclear installation is increasing. In order to reduce the height, there is a method which transfers the particles to a high position using a gas stream 1 1 as in the apparatus of the present invention illustrated in FIG. 1, but the device system which

  transfers particles by gas stream becomes com-

  plex and the occupancy area becomes larger so that the layout and operation become more complicated. In such an environment, increasing the number of revolutions is not the best solution and improving the efficiency of the multiplicity reaction becomes difficult.

  Furthermore, in the apparatus of the present invention

  tion, because the particles transfer almost horizontally, the height of the device can be made lower and, for the transfer of particles, no special device is necessary. The apparatus can therefore be extremely simplified. The multiplication for improving the efficiency of the fluid bed reaction apparatus can be easily obtained by increasing the number of chambers and, furthermore, since the operating conditions in each chamber are chosen arbitrarily, can easily improve reaction efficiency by appropriately changing conditions

Operating.

  In the apparatus of the present invention, the multipli-

  cation in the transformation region from U02 to UF4 is a

good example of the above.

  The apparatus of the present invention is further mainly composed of a fluid bed reaction process, but, as described above, in addition to the fluid bed, a moving bed and a fixed bed can be easily obtained by changing the amount gas supplied, therefore, this has for example the advantage that it can also be applied

  instantly to a process whose improved efficiency

  reaction efficiency is obtained by combining a fluid bed reaction process and a bed reaction process

mobile.

  To mount the partition in each chamber, there are two methods, namely a method in which the partition is mounted in contact with the base surface of the fluid bed and a method in which the partition is mounted on

  an open gap on the base surface of the fluid bed.

  In the known fluid bed reaction apparatus of the multi-chamber type of FIG. 3 (a) and fig. 3 (b) we see, with regard to the partition, that

  only one of these two types of partitions has been fitted.

  In the system of fig. 3 (a) in which the partition is mounted in contact with the base surface of the fluid bed, when coarse particles are mixed with the particles, this results in the problem that the coarse particles remain in the base part of the fluid bed and do not not protrude from the bulkhead, which results in

  formation of the fluid bed on the layer of coarse particles.

  In the system of fig. 3 (b) in which the partition is mounted on an open gap on the base surface of the fluid bed, a problem of this type is not created as in fig. 3 (a), but the probability of particle short-circuiting between the chambers becomes greater and harmful

to the reaction.

  On the contrary, by combining these two systems as shown in fig. 3 (c), the above problems can be avoided and, at the same time, the reaction efficiency can be increased because the flow of the particles approaches a flow of the piston. In addition, by combining these two systems, it is possible to obtain a combination of the fluid bed and the movable bed, which is impossible in known systems. In the present example, a plate type fluid bed reaction apparatus is shown as a unified system. But in the case where the formation of a unified system is difficult or not rational due to the fact that several kinds of materials are used, and in the case where a unified system is difficult to obtain by an unequal or irregular control of the operating conditions involving a

  thermal expansion due to operating temperatures

  extremely different, you can avoid the problems

  above without changing the basic idea of the present invention

  tion by connecting several reaction devices by connecting pipes. Fig. 4 is an example of the above case. In fig. 4, 50 to 52 denote a divided reaction apparatus having a stretching function when a loss of

  such thermal expansion is necessary. In addition, the device

  The advantage of the present invention is that the degree of freedom in the arrangement of the devices is extremely great. Figs. 5 (a), 5 (b) and 5 (d) respectively show arrangements of plate type fluid bed reaction apparatus according to the present invention. Furthermore, as shown in FIG. 6, using a system which extends

  a fluid bed type plate vertically and horizontally-

  ment, one can respectively obtain a series of processes by its horizontal extension and a processing capacity

  easily increased from the device by its vertical extension

  cal. Thus, plate-type fluid bed reaction apparatus can cover faults of reaction apparatus

  usual fluid bed which cannot be easily increased

  your. As seen in fig. 7, when the chambers 80 to 83 are provided close to each other, the apparatus of the present invention can be used as an apparatus

  single type fluid bed reaction.

  The present invention makes it possible to obtain the following effects by adopting the embodiment described above, / In the example, it is from the present invention that the particles are transferred approximately in the horizontal direction, the height of the apparatus can be reduced and, moreover, the fact that no device is necessary for the transfer of the particles, the structure

  of the device can be simplified.

  2 / In the apparatus of the present invention, a multiplication of the apparatus in addition to two chambers is made possible, and the operating system of each chamber can be chosen arbitrarily, so that the reaction efficiency of the device can be increased by modifying respectively

  appropriate the operating system.

  3 / By gas sealing the reaction gas, its undesirable action can be avoided and, at the same time,

  can increase the flow of particles.

  4 / The degree of freedom of the arrangement of the devices

  reils is extremely large, as shown in fig. 5.

   / When the layout of each room is made similar to that in fig. 7, the apparatus can also be used as a fluid bed reaction apparatus

  of the recycling type and which recycles particles.

  6 / In the case of a bed reaction apparatus

  fluid of the plate type, a series of processes can be carried out by extending the device in the horizontal direction, and one can

  increase the processing capacity of the device by increasing it by extending the device in the

vertical direction.

  7 / In the apparatus of the present invention comprising two chambers, when UF4 is transformed into UF6, the quantity

  of gaseous F applied to the two chambers can be respected

  set and therefore more can be used

  of F2 gas that a fluid bed reaction apparatus includes

one room only.

Claims (5)

  1 - Fluid bed reaction apparatus of the multi-chamber type comprising more than two chambers formed by dividing its fluid bed part and its wind boot part using partitions, characterized in that each   chambers thus divided is attached to a gas separator   particles and receives a reaction gas and / or an inert gas whose composition, flow rate and temperature can be chosen arbitrarily and in each of the chambers thus divided, a fluid bed, a movable bed or a fixed bed is formed under the influence of the regulation of particle formation, the gas-particle reaction and   the amount of particles transferred between the chambers.   2 - Fluid bed reaction apparatus of the multi-chamber type comprising more than two chambers formed by dividing its fluid bed part and its wind box part by means of partitions, characterized in that each of the chambers thus divided receives a reaction gas and / or an inert gas whose composition the flow rate and the temperature can be chosen arbitrarily, and in each of the chambers thus divided is formed a fluid bed, a moving bed or a fixed bed with gas tightness of said gas reaction gas under the influence of regulation of particle formation, gas-particle reaction and quantity   particles transferred between the chambers.   3 - Fluid bed type reaction apparatus   several chambers according to one of claims 1 or 2,   characterized in that the partition is mounted in contact with the base of the fluid bed or mounted on an open gap   on the base surface of the fluid bed.   4 - Fluid bed type reaction apparatus   several chambers according to one of claims 1 to 3,   characterized in that the movable bed is contained at least in one of the divided bedrooms.   5 - Fluid bed type reaction apparatus   several chambers according to one of claims 1 to 4,   characterized in that the multi-chamber type fluid bed reaction apparatus is a plate type fluid bed reaction apparatus