A fixed bed reactor

Abstract

The present invention relates to the technical field of reactors, and discloses a fixed bed reactor, including a shell, a feed pipe, an air duct, a slag discharge pipe and a separation device, wherein the separation device is arranged inside the shell and divides the inside of the shell into a reaction zone and a settling zone below the reaction zone, the reaction zone and the settling zone are connected through the separation device, the feed pipe, the slag discharge pipe and the air duct are all arranged on the shell, the feed pipe is connected to the reaction zone, and the slag discharge pipe and the air duct are both connected to the settling zone. The present invention quickly provides heat for the reaction by heating a medium, and there is no need to limit the volume of the fixed bed reactor in order to ensure that the outside can continuously supply heat as in the prior art, so that the large-scale fixed bed reactor can be realized; and slag is discharged during the reaction process to avoid the continuous accumulation of sludge and waste residue inside the shell, and space is provided for continuous feeding inside the fixed bed reactor, thereby realizing continuous feeding, and then realizing continuous reaction, and the fixed bed reactor can operate continuously.

Description

Technical Field

[0001] The invention relates to the technical field of reactors, in particular to a fixed bed reactor. Background Art

[0002] In the field of petrochemical industry, oil sludge undergoes cracking reaction under the catalytic action of a catalyst, and the cracking reaction is usually carried out in a fixed bed reactor. The characteristic of a fixed bed reactor is that the solid particles filled in the equipment are fixed and motionless, which is different from a moving bed and a fluidized bed in which solid materials move in the equipment. During the reaction, the amount of waste residue gradually increases. In order to ensure the normal progress of the cracking reaction, the fixed bed reactor needs to continuously enter fresh oil sludge, but the internal space of the current fixed bed reactor is limited, and the waste residue after the reaction cannot be continuously discharged, resulting in the inability to achieve continuous feeding. In the prior art, a fixed bed reactor is provided with a heating device on the outside of itself, and the heat transfer capacity is limited. If the waste residue is continuously discharged, the waste residue will continuously take away the internal heat of the fixed bed reactor, resulting in the internal temperature of the fixed bed reactor failing to reach the required temperature for the cracking reaction. Summary of the invention

[0003] The purpose of the present invention is to provide a fixed bed reactor which can discharge slag during the reaction process, provide space for continuous feeding inside the fixed bed reactor, and realize continuous feeding.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a fixed bed reactor, comprising a shell, a feed pipe, an air duct, a slag discharge pipe and a separation device, wherein the separation device is arranged inside the shell and divides the interior of the shell into a reaction zone and a sedimentation zone below the reaction zone, the reaction zone and the sedimentation zone are connected through the separation device, the feed pipe, the slag discharge pipe and the air duct are all arranged on the shell, the feed pipe is connected to the reaction zone, and the slag discharge pipe and the air duct are both connected to the sedimentation zone.

[0005] Optionally, the separation device is a filter screen, and the filter holes of the filter screen are larger than the particle size of the ash and smaller than the particle size of the catalyst.

[0006] Optionally, it also includes a reagent unloading device, which includes a first reagent unloading pipe and a second reagent unloading pipe, the first reagent unloading pipe is arranged on the shell and located at the bottom of the reaction zone, one end of the first reagent unloading pipe away from the shell and one end of the second reagent unloading pipe are connected through a first valve, and the end of the second reagent unloading pipe away from the first reagent unloading pipe is provided with a second valve.

[0007] Optionally, a first ventilation pipe is further provided on the first agent unloading pipe, one end of the first ventilation pipe is connected to the first agent unloading pipe, and the other end of the first ventilation pipe is provided with a third valve.

[0008] Optionally, a second ventilation pipe is further provided on the second agent unloading pipe, one end of the second ventilation pipe is connected to the second agent unloading pipe, and the other end of the second ventilation pipe is provided with a fourth valve.

[0009] Optionally, a catalyst replenishing device is further included, which includes a storage tank and an addition pipe. The addition pipe is arranged on the shell and is connected to the reaction zone. The storage tank and the addition pipe are connected through a fifth valve.

[0010] Optionally, the catalyst replenishing device further includes a third ventilation pipe, one end of the third ventilation pipe is connected to the storage tank, and the other end of the third ventilation pipe is provided with a sixth valve.

[0011] Optionally, the catalyst replenishing device further includes a hopper, and the hopper is connected to the storage tank via a seventh valve.

[0012] Optionally, a fourth ventilation pipe is further included, wherein the fourth ventilation pipe is arranged on the top of the shell and is connected to the reaction zone.

[0013] Optionally, a fifth ventilation pipe is further included, wherein the fifth ventilation pipe is arranged at the bottom of the shell and is connected to the sedimentation area.

[0014] The fixed bed reactor of the embodiment of the present invention has the following beneficial effects compared with the prior art:

[0015] A fixed bed reactor according to an embodiment of the present invention comprises a shell, a feed pipe, an air duct, a slag discharge pipe and a separation device, wherein the separation device is arranged inside the shell and divides the inside of the shell into a reaction zone and a sedimentation zone below the reaction zone, the reaction zone and the sedimentation zone are connected through the separation device, the feed pipe, the slag discharge pipe and the air duct are all arranged on the shell, the feed pipe is connected to the reaction zone, and the slag discharge pipe and the air duct are connected to the sedimentation zone. The sludge is mixed with the heating medium and enters the reaction zone from the feed pipe for cracking reaction. The heating medium ensures that the temperature of the reaction zone can reach the temperature required for the cracking reaction and continuously supplies heat to the reaction zone, breaking through the volume limit of the fixed bed reactor due to ensuring continuous external heat supply, and realizing large-scale fixed bed reactors. The waste residue and oil and gas after the reaction enter the sedimentation zone through the separation device. The waste residue falls to the bottom of the shell due to its own gravity and is discharged from the slag discharge pipe, while the oil and gas are discharged through the air guide pipe. The waste residue is continuously separated in the reaction zone and enters the sedimentation zone, thereby realizing slag discharge during the reaction process, avoiding the continuous accumulation of sludge and waste residue inside the shell, and providing space for continuous feeding inside the fixed bed reactor, thereby realizing continuous feeding, and then realizing continuous reaction, and the fixed bed reactor can operate continuously. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0017] In the figure, 1. shell; 2. feed pipe; 3. air guide pipe; 4. slag discharge pipe; 5. separation device; 6. unloading device; 7. catalyst replenishing device; 8. fourth ventilation pipe; 9. fifth ventilation pipe; 11. reaction zone; 12. sedimentation zone; 13. first manhole; 14. second manhole; 15. agitator; 61. first unloading pipe; 62. second unloading pipe; 63. first valve; 64. second valve; 65. first ventilation pipe; 66. third valve; 67. second ventilation pipe; 68. fourth valve; 71. storage tank; 72. addition pipe; 73. fifth valve; 74. third ventilation pipe; 75. sixth valve; 76. hopper; 77. seventh valve. DETAILED DESCRIPTION

[0018] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0019] In the description of the present invention, it should be noted that the terms "lateral", "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] Please refer to Figure 1A fixed bed reactor according to a preferred embodiment of the present invention comprises a shell 1, a feed pipe 2, an air guide pipe 3, a slag discharge pipe 4 and a separation device 5. The separation device 5 is arranged inside the shell 1 and divides the inside of the shell 1 into a reaction zone 11 and a settling zone 12 below the reaction zone 11. The reaction zone 11 is connected to the settling zone 12 through the separation device 5. The feed pipe, the slag discharge pipe 4 and the air guide pipe 3 are all arranged on the shell 1. The feed pipe 2 is connected to the reaction zone 11, and the slag discharge pipe 4 and the air guide pipe are both connected to the settling zone 12. The slag discharge pipe 4 is arranged at the bottom of the shell 1.

[0023] Before the sludge enters the shell 1, a catalyst is pre-installed in the reaction zone 11 inside the shell 1. The sludge is mixed with the heating medium, and then enters the reaction zone 11 inside the shell 1 through the feed pipe 2, and a cracking reaction occurs in the reaction zone 11. A stirrer 15 is provided at the top of the reaction zone 11, and the blades of the stirrer 15 can withstand high temperatures.

[0024] The heating medium can directly heat the sludge to the temperature required for the cracking reaction. In this embodiment, it can be heated to 400°C. The heating medium can be selected from superheated steam, superheated oil gas or other superheated inert medium, and the heating device is set to continuously input heat to the reaction zone 11. In the prior art, indirect heating is usually used outside the shell 1 for heating, so continuous heat supply is subject to factors such as the power, volume, heat transfer area and heat transfer rate of the heating party, which limits the volume of the fixed bed reactor and makes it difficult to achieve continuous heat supply. In this embodiment, the heating medium is mixed with the sludge and enters the reaction zone 11 together. The heating medium can quickly provide heat for the reaction, and there is no need to limit the volume of the fixed bed reactor in order to ensure continuous external heat supply as in the prior art, so that the fixed bed reactor can be large-scale. In the reaction zone 11, the sludge cracking reaction generates ash and oil gas, and the ash and oil gas enter the settling zone 12 through the separation device 5. The ash falls to the bottom of the sedimentation zone 12, i.e., the bottom of the shell 1, due to its own gravity, and is then discharged from the slag discharge pipe 4. The oil and gas are discharged through the gas guide pipe 3. The waste residue is continuously separated in the reaction zone 11 and enters the sedimentation zone 12, so as to avoid the continuous accumulation of sludge and waste residue inside the shell 1, and provide space for continuous feeding inside the fixed bed reactor, thereby achieving continuous feeding and continuous reaction. In addition, continuously separating the waste residue from the sludge and catalyst can also reduce the adverse effect of the waste residue on the catalyst reaction efficiency and ensure the reaction efficiency.

[0025] In this embodiment, a filter is provided in the air guide pipe 3 to prevent ash particles from being brought out when the oil and gas are discharged and blocking the air guide pipe 3, and to prevent ash particles from entering the downstream equipment of the fixed bed reactor. In this way, ash and oil and gas are continuously discharged, providing space for continuous feeding inside the fixed bed reactor, and ensuring the stability of the pressure inside the fixed bed reactor, thereby achieving continuous feeding, and then achieving continuous cracking reaction, and improving work efficiency.

[0026] It should be noted here that the fixed bed reactor also includes a fourth vent pipe 8, which is arranged at the top of the shell 1, and the fourth vent pipe 8 is connected to the reaction zone 11. Since the cracking reaction is carried out at a relatively high temperature, in other words, the temperature inside the shell 1 is relatively high, while the temperature outside the shell 1 is close to room temperature, the temperature gradient inside and outside the shell 1 is relatively large, which will affect the sealing effect of the shell 1, and the top of the shell 1 is a position where the sealing structure requires high requirements. The fourth vent pipe 8 is arranged here, and the cooling medium is injected through the fourth vent pipe 8. The cooling medium is usually a substance such as steam whose temperature is lower than the heating medium but higher than the temperature outside the shell 1. Since the sludge and the heating medium enter the reaction zone 11, the generated oil and gas will be forced to flow into the sedimentation zone 12 and then discharged by the air guide pipe 3, which causes the gas flow in the shell 1 to be from top to bottom, so the cooling medium will be retained at the top of the shell 1, that is, the top of the reaction zone 11, thereby reducing the temperature gradient inside and outside the shell 1 here, reducing the pressure of the sealing structure, preventing leakage, and improving safety.

[0027] In addition, it also includes a fifth vent pipe 9, which is arranged at the bottom of the shell 1 and is connected to the sedimentation area 12. The fifth vent pipe 9 can be introduced with hot steam to stir the ash that falls to the bottom of the sedimentation area 12 to prevent the ash from agglomerating and blocking the discharge pipe. Specifically, a loose coil connected to the fifth vent pipe 9 is provided at the bottom of the sedimentation area 12, and a blowing port is provided on the loose coil. Hot steam can enter the loose coil from the fifth vent pipe 9 and then be blown to the waste residue at the bottom of the sedimentation area 12 by the blowing port. In this way, the waste residue can be stirred by hot steam to prevent blockage, so that the waste residue can be discharged from the slag discharge pipe 4.

[0028] The separation device 5 is a filter screen, the filter holes of which are larger than the particle size of the ash and smaller than the particle size of the catalyst. In this way, the ash and oil gas can enter the settling zone 12 from the reaction zone 11 through the filter holes, while the catalyst will not enter the settling zone 12.

[0029] The fixed bed reactor of this embodiment further includes a discharge device 6, which includes a first discharge pipe 61 and a second discharge pipe 62. The first discharge pipe 61 is arranged on the shell 1 and is located at the bottom of the reaction zone 11. The end of the first discharge pipe 61 away from the shell 1 and the end of the second discharge pipe 62 are connected through a first valve 63, and the end of the second discharge pipe 62 away from the first discharge pipe 61 is provided with a second valve 64. The first discharge pipe 61 is connected to the second discharge pipe 62. The catalyst may involve the problem of insufficient activity after use. In this embodiment, the discharge device 6 is provided to discharge the catalyst with insufficient activity.

[0030] The first unloading pipe 61 is also provided with a first vent pipe 65, one end of which is connected to the first unloading pipe 61, and the other end of which is provided with a third valve 66. The first vent pipe 65 is connected to the first unloading pipe 61. The second unloading pipe 62 is also provided with a second vent pipe 67, one end of which is connected to the second unloading pipe 62, and the other end of which is provided with a fourth valve 68. The second vent pipe 67 is connected to the second unloading pipe 62. When discharging the catalyst, the second valve 64 and the fourth valve 68 are first opened to preheat the pipeline, and after discharging the air from the second unloading pipe 62, the second valve 64 and the fourth valve 68 are closed, the second valve 66 is opened, and the first valve 63 is slowly opened after a few minutes. It is worth mentioning that the opening speed and valve position of the first valve 63 should be controlled. If the temperature of the unloading pipe rises, it means that the catalyst is discharged, and the faster the temperature rises, the greater the catalyst discharge amount. At this time, the fourth valve 68 is opened again, and then the second valve 64 is slowly opened. The valve position opening of the second valve 64 will control the speed of the catalyst discharge, so that the catalyst enters the second unloading pipe 62 through the first unloading pipe 61 and is discharged from the second unloading pipe 62. The opening of the first valve 63 and the second valve 64 controls the speed of the catalyst discharge. A first vent pipe 65 and a second vent pipe 67 are provided to blow steam into the first unloading pipe 61 and the second unloading pipe 62 to loosen the catalyst and facilitate the discharge of the catalyst. After the catalyst is discharged from the first unloading pipe 61, the first valve 63 is closed first. After all the catalyst in the second unloading pipe 62 is discharged, the second valve 64 and the fourth valve 68 are closed, and finally the third valve 66 is closed.

[0031] In order to ensure the rate of the cracking reaction, it is necessary to input fresh catalyst into the reaction zone 11. The fixed bed reactor of this embodiment also includes a catalyst replenishing device 7, which includes a storage tank 71 and an addition pipe 72. The addition pipe 72 is arranged on the shell 1 and is connected to the reaction zone 11. The storage tank 71 is connected to the addition pipe 72 through a fifth valve 73. Fresh catalyst is stored in the storage tank 71, and the catalyst can enter the reaction zone 11 through the addition pipe 72. The catalyst replenishing device 7 also includes a third vent pipe 74, one end of which is connected to the storage tank 71, and the other end of the third vent pipe 74 is provided with a sixth valve 75. The third vent pipe 74 is connected to the interior of the storage tank 71. The catalyst replenishing device 7 also includes a hopper 76, which is connected to the storage tank 71 through a seventh valve 77. The seventh valve 77 is opened, and fresh catalyst can enter the storage tank 71 through the hopper 76. When the catalyst needs to be added, the heating medium is introduced into the third ventilation pipe 74 to preheat the catalyst, and then the seventh valve 77 is closed and pressure is accumulated in the storage tank 71. After the pressure is accumulated, the fifth valve 73 is opened, and the fresh catalyst enters the reaction zone 11 through the addition pipe 72. In this embodiment, the pressure accumulation can be ended when the pressure of the storage tank 71 is higher than the pressure of the reaction zone 11 by 0.1 MPa. The purpose of the pressure accumulation is to facilitate the pressing of the fresh catalyst into the reaction zone 11.

[0032] In addition, the shell 1 is provided with a first manhole 13 and a second manhole 14, the first manhole 13 is connected to the reaction zone 11, and the second manhole 14 is connected to the sedimentation zone 12, and manhole covers are provided on the first manhole 13 and the second manhole 14. The provision of the first manhole 13 and the second manhole 14 facilitates the staff to inspect the inside of the shell 1.

[0033] It should be added that the fixed bed reactor provided in this embodiment can also be applied to the recycling of waste plastics.

[0034] The working process of the present invention is as follows: oil sludge and heating medium enter the reaction zone 11 from the feed pipe 2, a cracking reaction occurs in the reaction zone 11 to generate ash and oil gas, the ash and oil gas enter the sedimentation zone 12 through the separation device 5, the ash is discharged through the discharge pipe, and the oil gas is discharged through the air guide pipe 3.

[0035] In summary, an embodiment of the present invention provides a fixed bed reactor, which is equipped with a separation device 5, and the ash is discharged through the slag discharge pipe 4, and the oil and gas are discharged through the air guide pipe 3, so as to provide space for continuous feeding inside the fixed bed reactor, and can also ensure the pressure stability inside the fixed bed reactor, thereby realizing continuous feeding, and then realizing continuous cracking reaction; a catalyst unloading device 6 and a catalyst replenishing device 7 are also provided, which can discharge catalysts with insufficient activity, replenish fresh catalysts, and maintain the catalyst in the reaction zone 11 with a certain activity, thereby ensuring the stability of product properties and product yields.

[0036] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A fixed bed reactor, characterized in that: It comprises a shell, a feed pipe, an air duct, a slag discharge pipe and a separation device, wherein the separation device is arranged inside the shell and divides the inside of the shell into a reaction zone and a settling zone below the reaction zone, the reaction zone and the settling zone are connected through the separation device, the feed pipe, the slag discharge pipe and the air duct are all arranged on the shell, the feed pipe is connected to the reaction zone, and the slag discharge pipe and the air duct are both connected to the settling zone; The separation device is a filter screen, the filter holes of which are larger than the particle size of the ash and smaller than the particle size of the catalyst; It also includes a reagent unloading device, the reagent unloading device includes a first reagent unloading pipe and a second reagent unloading pipe, the first reagent unloading pipe is arranged on the shell and located at the bottom of the reaction zone, one end of the first reagent unloading pipe away from the shell and one end of the second reagent unloading pipe are connected through a first valve, and one end of the second reagent unloading pipe away from the first reagent unloading pipe is provided with a second valve; The heating medium ensures that the temperature of the reaction zone can reach the temperature required for the cracking reaction and continuously supplies heat to the reaction zone; The heating medium is superheated steam, superheated oil gas or other superheated inert medium.

2. The fixed bed reactor according to claim 1, characterized in that The first unloading pipe is also provided with a first ventilation pipe, one end of the first ventilation pipe is connected to the first unloading pipe, and the other end of the first ventilation pipe is provided with a third valve.

3. The fixed bed reactor according to claim 2, characterized in that The second agent unloading pipe is also provided with a second ventilation pipe, one end of the second ventilation pipe is connected to the second agent unloading pipe, and the other end of the second ventilation pipe is provided with a fourth valve.

4. The fixed bed reactor according to claim 1, characterized in that It also includes a catalyst replenishing device, which includes a storage tank and an addition pipe. The addition pipe is arranged on the shell and is connected to the reaction zone. The storage tank is connected to the addition pipe through a fifth valve.

5. The fixed bed reactor according to claim 4, characterized in that The catalyst replenishing device further includes a third ventilation pipe, one end of which is connected to the storage tank, and the other end of which is provided with a sixth valve.

6. The fixed bed reactor according to claim 5, characterized in that The catalyst replenishing device further includes a hopper, and the hopper is connected to the storage tank via a seventh valve.

7. The fixed bed reactor according to claim 1, characterized in that It also includes a fourth ventilation pipe, which is arranged on the top of the shell and is connected to the reaction zone.

8. The fixed bed reactor according to claim 1, characterized in that It also includes a fifth ventilation pipe, which is arranged at the bottom of the shell and is connected to the sedimentation area.

Images