Pulse fluidized bed and gas treatment system

Abstract

The application provides a pulse fluidized bed and a gas treatment system, and relates to the technical field of uranium conversion production processes.The pulse fluidized bed comprises a bed body, an air chamber fixedly connected with the bed body, a first gas inlet and a second gas inlet of the air chamber, a first air blowing device communicated with the first gas inlet through a first air duct, and a pulse device communicated with the second gas inlet through a second air duct; when the first air blowing device blows the first gas into the bed body through the first air duct and the first gas inlet, the pulse device blows the second gas into the bed body through the second air duct and the second gas inlet, and the second gas is a pulse gas flow.The scheme of the application enables the gas blown into the fluidized bed to fully contact with the material in the pulse fluidized bed, improves the utilization rate of the blown gas, and reduces the production cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of uranium conversion production process, in particular to a pulse fluidized bed and a gas treatment system. BACKGROUND

[0002] In the uranium purification and conversion production process in China, uranium tetrafluoride material is prepared into uranium hexafluoride through fluorination process. The fluorination process is the core key process for the preparation of uranium hexafluoride, specifically, uranium tetrafluoride reacts with fluorine gas to generate uranium hexafluoride in a fluidized bed reactor. In the process of preparing uranium hexafluoride, the traditional fluidized bed is prone to problems such as channeling, dead zone and local overheating. At the same time, in the process of preparing uranium hexafluoride, in order to promote the full reaction of uranium tetrafluoride and reduce the fluorination process slagging rate, a certain excess amount of fluorine gas needs to be ensured, so that the fluorine content in the tail gas is high. At present, the domestic main method is to treat the excess fluorine gas by carbonization furnace charcoal combustion. Although a horizontal stirring furnace has been developed for fluorine gas recycling, the device has problems such as poor sealing of the stirring shaft position, poor system operation stability, low fluorine gas utilization rate, and poor matching with the fluorination production system. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a pulse fluidized bed and a gas treatment system, which realizes the full contact of the material in the pulse fluidized bed with the inlet gas, improves the utilization rate of the inlet gas, and reduces the production cost.

[0004] To solve the above technical problems, the technical scheme of the present application is as follows:

[0005] The embodiment of the present application provides a pulse fluidized bed, which comprises:

[0006] a bed body;

[0007] a gas chamber fixedly connected with the bed body; the gas chamber has a first gas inlet and a second gas inlet;

[0008] the first gas inlet is communicated with a first gas blowing device through a first gas pipeline;

[0009] the second gas inlet is communicated with a pulse device through a second gas pipeline;

[0010] When the first gas blowing device blows the first gas into the bed body through the first gas pipeline and the first gas inlet, the pulse device blows the second gas into the bed body through the second gas pipeline and the second gas inlet, and the second gas is a pulse gas flow.

[0011] Optionally, the bed body comprises:

[0012] a reaction section and an enlarged section formed integrally;

[0013] The reaction section is located below the expansion section, and the gas chamber is in communication with the reaction section.

[0014] Optionally, the reaction section has a first feeding port and a first discharging port.

[0015] The first feeding port is in communication with a feeding screw conveyor.

[0016] The first discharging port is in communication with a discharging screw conveyor.

[0017] Optionally, a plurality of dust removal devices are arranged in the expansion section.

[0018] Optionally, the reaction section is provided with a first flange plate, and the gas chamber is provided with a second flange plate.

[0019] The gas chamber and the reaction section are fixedly connected through the first flange plate and the second flange plate.

[0020] Optionally, a distribution plate is arranged between the first flange plate and the second flange plate, and a plurality of uniformly distributed gas permeable holes are arranged on the distribution plate.

[0021] Optionally, an expansion section head is arranged on the expansion section, the expansion section head is in sealing connection with the expansion section, and a tail gas outlet pipe is arranged on the expansion section head.

[0022] Embodiments of the present application also provide a gas treatment system, comprising:

[0023] A feeding screw conveyor;

[0024] A discharging screw conveyor and a pulse fluidized bed.

[0025] The pulse fluidized bed comprises:

[0026] A gas chamber fixedly connected with the bed body; the gas chamber has a first gas inlet and a second gas inlet.

[0027] The first gas inlet is in communication with a first gas blowing device through a first air pipe;

[0028] The second gas inlet is in communication with a pulse device through a second air pipe.

[0029] The feeding screw conveyor feeds materials to the bed body, the first gas blowing device blows a first gas into the bed body through the first air pipe and the first gas inlet, the pulse device blows a second gas into the bed body through the second air pipe and the second gas inlet, the second gas is a pulse gas flow, so that the materials in the bed body and the second gas react in the bed body.

[0030] Optionally, the gas treatment system further comprises:

[0031] A spring box is fixedly connected with the feeding end of the discharging screw conveyor.

[0032] A conduit has a first end fixedly connected with the bed body and in communication with the first discharging port, and a second end slidably connected with the spring box.

[0033] Optionally, the gas treatment system further comprises a discharging hopper arranged below the discharging screw conveyor and in communication with the discharging end of the discharging screw conveyor.

[0034] The above technical solutions of the present application have at least the following technical effects:

[0035] The pulse fluidized bed comprises a bed body, a gas chamber fixedly connected with the bed body, the gas chamber having a first gas inlet and a second gas inlet, the first gas inlet being in communication with a first gas blowing device through a first gas channel, and the second gas inlet being in communication with a pulse device through a second gas channel, wherein when the first gas blowing device blows the first gas into the bed body through the first gas channel and the first gas inlet, the pulse device blows the second gas into the bed body through the second gas channel and the second gas inlet, and the second gas is a pulse gas flow. The problems of channeling, dead zone and local overheating in the conventional fluidized bed are solved, the gas blown into the fluidized bed can be fully contacted with the material in the pulse fluidized bed, the utilization rate of the blown gas is improved, and the production cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a structural schematic view of the gas treatment system of the present application;

[0037] Figure 2 is a structural schematic view of the pulse fluidized bed of the present application;

[0038] Figure 3 is a structural schematic view of the connection between the bed body and the gas chamber of the pulse fluidized bed of the present application.

[0039] REFERENCE SIGNS:

[0040] 11, reaction section; 12, expansion section; 13, first gas inlet; 14, first discharging port; 15, first flange; 16, temperature measuring device; 21, dust removal device; 22, expansion section head; 3, gas chamber; 31, first gas inlet; 32, second gas inlet; 33, second flange; 4, distribution plate; 5, feeding screw conveyor; 51, feeding hopper; 6, discharging screw conveyor; 61, spring box; 7, conduit; 8, discharging hopper. DETAILED DESCRIPTION

[0041] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0042] like Figures 1 to 3 As shown, an embodiment of the present invention provides a pulse fluidized bed, comprising:

[0043] Bed;

[0044] An air chamber 3 fixedly connected to the bed; the air chamber 3 has a first air inlet 31 and a second air inlet 32;

[0045] The first air inlet 31 is connected to the first air blowing device through a first ventilation pipe;

[0046] The second air inlet 32 ​​is connected to the pulse device through a second ventilation pipe;

[0047] When the first blowing device blows the first gas into the bed through the first ventilation pipe and the first air inlet 31 , the pulse device blows the second gas into the bed through the second ventilation pipe and the second air inlet 32 ​​. The second gas is a pulsed gas flow.

[0048] In this embodiment, the air chamber 3 is a conical structure, the bottom of the air chamber 3 is fixedly connected to and communicated with the bed body, the first air inlet 31 is arranged at the top of the air chamber 3, and the second air inlet 32 ​​is arranged on the side wall of the air chamber 3. The first gas introduced into the first air inlet 31 is an inert gas and does not react with the material, and the second gas introduced into the second air inlet 32 ​​is a reaction gas that needs to react with the material; the first blowing device is mainly used to provide a continuous and stable airflow to the bed body of the pulse fluidized bed. The first blowing device uses the first gas to enable the pulse fluidized bed to maintain a fluidized state during operation; the pulse device provides a pulse airflow to the pulse fluidized bed through the second gas, and periodically acts on the pulse fluidized bed to realize the pulse characteristics of the pulse fluidized bed, so that the material in the bed body of the pulse fluidized bed can roll and flow under the action of the pulse, thereby preventing the pulse fluidized bed from having channel flow, dead zone and local overheating.

[0049] In the embodiment, the pulse device mainly controls the on-off of the airflow in the second aeration pipeline indirectly, so that the second gas is blown into the bed body in the form of pulse airflow, the pulse device can be a pulse electromagnetic valve controlled by the PLC, the pulse electromagnetic valve is installed in the second aeration pipeline, then the opening and closing of the pulse electromagnetic valve is controlled by the PLC, so that the second gas enters the bed body of the pulse fluidized bed in the form of pulse airflow, and the size and pulse frequency of the airflow can also be controlled by the pulse electromagnetic valve, rectangular wave pulses and sinusoidal wave pulses are generated, and the actual demand can be adjusted and optimized.

[0050] In the embodiment, when the pulse fluidized bed works, the first blowing device blows the first gas into the bed body, so that the material in the bed body is continuously kept in a fluidized state, and the pulse device periodically provides the second gas in the form of pulses into the bed body, so that the material can roll and flow under the action of the pulses, and the material is fully contacted and reacted with the second gas in the rolling process, so that the pulse fluidized bed solves the problems of channeling, dead zone and local overheating of the ordinary fluidized bed, and the utilization rate of the second gas is improved and the production cost is reduced.

[0051] In an optional embodiment of the present application, the bed body comprises:

[0052] The reaction section 11 and the expansion section 12 are integrally formed.

[0053] The reaction section 11 is located below the expansion section 12, and the gas chamber 3 is in communication with the reaction section 11.

[0054] A plurality of dust removal devices 21 are arranged in the expansion section 12.

[0055] The expansion section 12 is provided with an expansion section head 22, the expansion section head 22 is in sealing connection with the expansion section 12, and the expansion section head 22 is provided with a tail gas outlet pipe.

[0056] In the embodiment, the expansion section head 22 is mainly used for sealing the top of the expansion section 12, the material and the second gas introduced into the reaction section 11 are reacted, the remaining gas after the reaction is introduced into the dust removal device 21 together with the first gas for dust removal treatment, and then is discharged through the tail gas outlet pipe on the expansion section head 22, and the dust removal device 21 is mainly used for preventing the material particles from being discharged through the tail gas outlet pipe on the expansion section head 22.

[0057] In an optional embodiment of the present application, the reaction section 11, the expansion section 12 and the gas chamber 3 are all made of Monel 400.

[0058] As Figure 1As shown, in an optional embodiment of the present invention, the reaction section 11 has a first feed port 13 and a first discharge port 14;

[0059] The first feed port 13 is connected to the feed screw conveyor 5;

[0060] The first discharge port 14 is communicated with the discharge screw conveyor 6 .

[0061] In this embodiment, the feed screw conveyor 5 feeds the material into the reaction section 11 through the first feed port 13 . After the reaction, the material flows into the discharge screw conveyor 6 through the first discharge port 14 and flows out through the discharge screw conveyor 6 .

[0062] like Figure 3 As shown, in an optional embodiment of the present invention, the reaction section 11 is provided with a first flange 15, and the gas chamber 3 is provided with a second flange 33;

[0063] The gas chamber 3 is fixedly connected to the reaction section 11 via a first flange 15 and a second flange 33 .

[0064] A distribution plate 4 is provided between the first flange 15 and the second flange 33 , and the distribution plate 4 is provided with a plurality of evenly distributed air holes.

[0065] In this embodiment, the first flange 15 and the second flange 33 are sealed and fixedly connected by bolts, and the distribution plate 4 is fixed between the reaction section 11 and the air chamber 3 through the first flange 15 and the second flange 33. The distribution plate 4 adopts a monel wire mesh distribution plate. The distribution plate 4 is mainly used to prevent the material in the bed from entering the air chamber 3 and blocking the second air inlet 32. At the same time, the continuous air intake of the first air inlet 31 can also prevent the air holes on the distribution plate 4 from being blocked by the material in the bed; the multiple evenly distributed air holes on the distribution plate 4 can make the gas blown into the air chamber 3 be divided into multiple streams and evenly blown into the bed, so that the material in the bed can be more fully in contact with the blown reaction gas, so that the reaction gas can fully react with the material, while accelerating the reaction speed.

[0066] In an optional embodiment of the present invention, a plurality of temperature measuring devices 16 are further provided on the bed for detecting the bed temperature in real time.

[0067] like Figure 1 As shown, an embodiment of the present invention provides a gas processing system, comprising:

[0068] Feed screw conveyor 5;

[0069] a discharge screw conveyor 6 and a pulse fluidized bed;

[0070] The pulse fluidized bed comprises a bed body;

[0071] A gas chamber 3 is fixedly connected with the bed body 3, and the gas chamber 3 has a first gas inlet 31 and a second gas inlet 32;

[0072] The first gas inlet 31 is communicated with the first gas blowing device through a first gas pipeline;

[0073] The second gas inlet 32 is communicated with the pulse device through a second gas pipeline;

[0074] Wherein, the feeding screw conveyor 5 feeds materials to the bed body, the first gas blowing device blows the first gas into the bed body through the first gas pipeline and the first gas inlet 31, the pulse device blows the second gas into the bed body through the second gas pipeline and the second gas inlet 32, the second gas is a pulse gas flow, so that the materials in the bed body and the second gas react in the bed body.

[0075] In the embodiment, the pulse fluidized bed is any one of the pulse fluidized beds described above, the discharge end of the feeding screw conveyor 5 is in sealed communication with the first feeding channel 13, and the spiral part of the feeding screw conveyor 5 extends into the bed body by about 50 mm; the discharging screw conveyor 6 is located below the pulse fluidized bed, and the feeding end of the discharging screw conveyor 6 is in sealed communication with the first discharging channel 14 of the pulse fluidized bed.

[0076] In an optional embodiment of the present application, a feeding hopper 51 for storing materials is arranged on the feeding screw conveyor 5, and the feeding hopper 51 is communicated with the feeding port of the feeding screw conveyor 5.

[0077] In an optional embodiment of the present application, the gas treatment system further comprises:

[0078] A spring box 61 is fixedly connected with the feeding end of the discharging screw conveyor 6;

[0079] A conduit 7 has a first end fixedly connected with the bed body and communicated with the first discharging port 14, and a second end slidably connected with the spring box 61.

[0080] In the embodiment, the design of the spring box 61 and the conduit 7 makes the materials discharged from the first discharging port 14 still be able to enter the discharging screw conveyor 6 without being affected when the pulse fluidized bed shakes during the working process.

[0081] In an optional embodiment of the present invention, the gas processing system further includes: a discharge hopper 8, which is arranged below the discharge screw conveyor 6 and is connected to the discharge end of the discharge screw conveyor 6.

[0082] The gas treatment system described in this embodiment can be used in the tail gas treatment process of the uranium tetrafluoride fluorination process. When in use, nitrogen can be selected as the first gas, the second gas is the tail gas to be treated, and the material is uranium tetrafluoride. When in use, the first gas is first introduced into the bed, and then the material is conveyed to the reaction section 11 through the feed screw conveyor 5. At the same time, the pulse device is turned on to introduce the second gas into the bed in a pulsed form, so that the second gas and the material can fully react in the reaction section 11. The remaining gas after the reaction is discharged together with the first gas through the tail gas outlet pipe on the expansion section head 22. The reacted material flows into the spring box 61 through the first discharge port 14 and the conduit 7, and enters the discharge screw conveyor 6 through the spring box 61, and finally flows into the discharge hopper 8 through the discharge screw conveyor 6 for recovery.

[0083] When the gas treatment system of the present invention is used in the tail gas treatment process of the uranium tetrafluoride fluorination process, the tail gas of the uranium tetrafluoride fluorination process can be reused under a sealed condition, while the utilization rate of the fluorine gas in the tail gas is improved, and the production cost is reduced.

[0084] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A pulse fluidized bed, characterized in that: include: Bed; An air chamber (3) fixedly connected to the bed; the air chamber (3) has a first air inlet (31) and a second air inlet (32); The first air inlet (31) is connected to the first air blowing device through a first ventilation pipe; The second air inlet (32) is connected to the pulse device through a second ventilation pipe; Wherein, when the first blowing device blows the first gas into the bed through the first ventilation pipe and the first air inlet (31), the pulse device periodically blows the second gas in the form of pulses into the bed through the second ventilation pipe and the second air inlet (32), and the second gas is a pulsed airflow; Wherein, the first gas is an inert gas and the second gas is a reactive gas; Wherein, the bed comprises: An integrally formed reaction section (11) and expansion section (12); The reaction section (11) is located below the expansion section (12), and the gas chamber (3) is in communication with the reaction section (11); The reaction section (11) is provided with a first flange (15), and the gas chamber (3) is provided with a second flange (33); The gas chamber (3) and the reaction section (11) are fixedly connected via a first flange (15) and a second flange (33); A distribution plate (4) is provided between the first flange (15) and the second flange (33), and a plurality of evenly distributed air holes are provided on the distribution plate (4); The bed is provided with a plurality of temperature measuring devices (16) for detecting the bed temperature in real time.

2. The pulse fluidized bed according to claim 1, characterized in that The reaction section (11) has a first feed port (13) and a first discharge port (14); The first feed port (13) is in communication with the feed screw conveyor (5); The first discharge port (14) is in communication with the discharge screw conveyor (6).

3. The pulse fluidized bed according to claim 1, characterized in that A plurality of dust removal devices (21) are provided in the expansion section (12).

4. The pulse fluidized bed according to claim 1, characterized in that An expansion section head (22) is provided on the expansion section (12), the expansion section head (22) is sealed and connected to the expansion section (12), and an exhaust gas outlet pipe is provided on the expansion section head (22).

5. A gas processing system, characterized in that: include: Feed screw conveyor (5); a discharge screw conveyor (6) and a pulse fluidized bed; The pulse fluidized bed comprises: a bed body; An air chamber (3) fixedly connected to the bed; the air chamber (3) has a first air inlet (31) and a second air inlet (32); The first air inlet (31) is connected to the first air blowing device through a first ventilation pipe; The second air inlet (32) is connected to the pulse device through a second ventilation pipe; wherein the feed screw conveyor (5) conveys material to the bed body, and when the first blowing device blows a first gas into the bed body through the first ventilation pipe and the first air inlet (31), the pulse device periodically blows a second gas in the form of a pulse into the bed body through the second ventilation pipe and the second air inlet (32), and the second gas is a pulsed airflow, so that the material in the bed body and the second gas react in the bed body; Wherein, the first gas is an inert gas and the second gas is a reactive gas; Wherein, the bed comprises: An integrally formed reaction section (11) and expansion section (12); The reaction section (11) is located below the expansion section (12), and the gas chamber (3) is in communication with the reaction section (11); The reaction section (11) is provided with a first flange (15), and the gas chamber (3) is provided with a second flange (33); The gas chamber (3) and the reaction section (11) are fixedly connected via a first flange (15) and a second flange (33); A distribution plate (4) is provided between the first flange (15) and the second flange (33), and a plurality of evenly distributed air holes are provided on the distribution plate (4); The bed is provided with a plurality of temperature measuring devices (16) for detecting the bed temperature in real time.

6. The gas processing system according to claim 5, characterized in that Also includes: A spring box (61), the spring box (61) being fixedly connected to the feed end of the discharge screw conveyor (6); A conduit (7), wherein a first end of the conduit (7) is fixedly connected to the bed and communicates with the first discharge port (14), and a second end of the conduit (7) is slidably connected to the spring box (61).

7. The gas processing system according to claim 5, characterized in that Also includes: A discharge hopper (8), wherein the discharge hopper (8) is arranged below the discharge screw conveyor (6) and is connected to the discharge end of the discharge screw conveyor (6).

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