Microsphere catalyst spray drying tower based on circulating gas distribution device

Abstract

The application discloses a microsphere catalyst spray drying tower based on a circulating gas distribution device, which comprises the microsphere catalyst spray drying tower, a circulating gas distribution device fixed at the top of the microsphere catalyst spray drying tower, a ring-shaped gas distribution chamber, the upper and lower sealing of the ring-shaped gas distribution chamber, the ring-shaped gas distribution chamber in communication with a gas inlet pipeline, the tangential ring of the gas inlet pipeline into the ring-shaped gas distribution chamber, and a center pipe fixed at the bottom of the ring-shaped gas distribution chamber and extending from the bottom of the ring-shaped gas distribution chamber and connected with the gas distribution device; the gas distribution device is connected with the microsphere catalyst spray drying tower, the application can adjust and control the gas distribution state, thereby avoiding the phenomenon of particle adhesion and tower adhesion, improving the product sphericity and optimizing the catalyst particle size distribution.

Description

Technical Field

[0001] This invention belongs to the field of petroleum catalytic cracking technology and relates to a microsphere catalyst spray drying tower based on a circulating gas distribution device. Background Technology

[0002] The catalytic cracking (FCC) process is a crucial production link in oil refining enterprises, playing a vital role in producing gasoline and diesel. The catalytic cracking reaction requires an FCC catalyst to accelerate the reaction; however, FCC catalysts age and deactivate after a certain number of cycles, resulting in significant consumption in continuous industrial production. Therefore, developing high-quality FCC catalysts has become a core technology for the refining industry to reduce costs, increase yield, and improve selectivity.

[0003] The main steps in FCC catalyst preparation include binder formation, gelation, colloid filtration, spray drying, and calcination. Spray drying, in particular, involves using different types of atomizers or atomization principles within a spray drying chamber to disperse the raw material slurry into fine droplets. These droplets then come into contact with a drying medium heated by an external heat source, achieving mass and heat transfer between the two materials to ultimately obtain a dried solid product. This is a typical process of synergistic mass and heat transfer. Currently, FCC spray drying equipment suffers from several problems. The similarity in flow state between the hot air and catalyst droplets in the spray tower leads to hot air flow deviation and catalyst backmixing. Furthermore, the similar open area ratios of the two-stage trays in the equipment affect the hot air distribution and the thermal energy utilization rate of the spray-calcination system, resulting in severe particle adhesion, tower sticking, and poor product sphericity and particle size distribution. These issues significantly impact the yield of FCC microsphere catalysts and increase preparation costs. Summary of the Invention

[0004] The purpose of this invention is to provide a microsphere catalyst spray drying tower based on a circulating gas distribution device, which can adjust and control the gas distribution state, thereby avoiding particle adhesion and tower sticking, improving product sphericity and optimizing catalyst particle size distribution.

[0005] The technical solution adopted in this invention is:

[0006] A microsphere catalyst spray drying tower based on a circulating gas distribution device includes a microsphere catalyst spray drying tower, a circulating gas distribution device fixed at the top of the microsphere catalyst spray drying tower, the circulating gas distribution device including an annular gas distribution chamber, the annular gas distribution chamber being sealed at the top and bottom, the annular gas distribution chamber being connected to an inlet pipe, the inlet pipe being tangentially inserted into the annular gas distribution chamber, a central pipe being fixed at the bottom of the annular gas distribution chamber, the central pipe extending from the bottom of the annular gas distribution chamber and connected to the gas distribution device; the gas distribution device is introduced into the microsphere catalyst spray drying tower.

[0007] The invention is further characterized by:

[0008] There are two intake pipes, which are symmetrically and tangentially connected to the annular gas distribution chamber.

[0009] The annular gas distribution chamber is a frustum, and the projected area of ​​the upper part of the frustum is 1 / 3 of the projected area of ​​the lower part; the diameter of the lower part of the annular gas distribution chamber is the same as the diameter of the microsphere catalyst spray drying tower body.

[0010] The annular gas distribution chamber is connected to the gas distribution device via a perforated plate. The gas distribution device is a two-stage gas distributor or a tubular distributor with an opening ratio of 0.5% to 50%.

[0011] Furthermore, the annular gas distribution chamber and the gas distribution device are connected by a perforated plate. The gas distribution device consists of two secondary gas distributors with an opening rate of 15%. The distance between two adjacent secondary distributors is 1 / 5 to 5 of their diameter.

[0012] The central tube is a circular or rectangular tube, and the distance between the upper end of the central tube and the annular gas pre-distribution chamber is 1 / 50 to 50 of its diameter.

[0013] Furthermore, the central tube is a circular tube, and the cross-sectional area of ​​the central tube is 1 / 10 to 9 / 10 of the projected cross-section of the annular gas distribution chamber.

[0014] The microsphere catalyst spray drying tower has a cylindrical body, a catalyst outlet at the bottom, and an extended colloid input mechanism inside the tower body.

[0015] Furthermore, the number of centrally symmetrical colloid input mechanisms is set to four.

[0016] Furthermore, the bottom of the microsphere catalyst spray drying tower is a cone, the catalyst outlet is located at the bottom of the cone, and a gas outlet is provided on the side wall of the cone.

[0017] The beneficial effects of this invention are:

[0018] High-temperature gas enters the annular gas distribution chamber symmetrically through a tangential inlet pipe. After swirling upwards and reversing, it exits through the central pipe and passes through a gas distribution device before contacting the microsphere catalyst slurry from the colloidal input mechanism. The FCC catalyst slurry enters the microsphere catalyst spray drying tower from the slurry nozzle of the colloidal input mechanism to complete the spray drying process, yielding the FCC catalyst. Under gravity, gas-solid separation is achieved, with the gas and catalyst particles exiting separately from the bottom cone of the microsphere catalyst spray drying tower. Attached Figure Description

[0019] Figure 1 This is a structural diagram of a microsphere catalyst spray drying tower based on a circulating gas distribution device according to the present invention;

[0020] Figure 2 for Figure 1 Top view;

[0021] Figure 3 This is a structural diagram of the circulating gas distribution device in this invention.

[0022] In the attached diagram: 1. Inlet pipe; 2. Annular gas distribution chamber; 3. Central pipe; 4. Gas distribution device; 5. Colloidal input mechanism; 6. Microsphere catalyst spray drying tower; 7. Gas outlet; 8. Catalyst outlet. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0024] This invention provides a microsphere catalyst spray drying tower based on a circulating gas distribution device, such as... Figures 1-3 The system includes a microsphere catalyst spray drying tower 6, with a circulating gas distribution device fixed at the top. The circulating gas distribution device includes an annular gas distribution chamber 2, which is sealed at the top and bottom. The annular gas distribution chamber 2 is connected to an inlet pipe 1, and there are two inlet pipes 1 that are symmetrically and tangentially connected to the annular gas distribution chamber 2. A central pipe 3 is also fixed at the bottom of the annular gas distribution chamber 2. The central pipe 3 extends from the bottom of the annular gas distribution chamber 2 and is connected to the gas distribution device 4. The gas distribution device 4 is connected to the microsphere catalyst spray drying tower 6.

[0025] The annular gas distribution chamber 2 is cylindrical, frustum, or conical. When the annular gas distribution chamber 2 is frustum, the projected area of ​​the upper end is 1 / 3 of the projected area of ​​the lower end. The diameter of the lower end of the annular gas distribution chamber 2 is consistent with the diameter of the cylinder of the microsphere catalyst spray drying tower 6.

[0026] The annular gas distribution chamber 2 and the gas distribution device 4 are connected by a perforated plate. The gas distribution device 4 is a two-stage gas distributor or a tubular distributor with an opening ratio of 0.5~50%. When the gas distribution device 4 is a two-stage gas distributor, it is preferable to use two two-stage gas distributors with an opening ratio of 15% and the distance between two adjacent two-stage distributors is 1 / 5 of its diameter.

[0027] The central tube 3 is open at both ends and can be a circular or rectangular tube, preferably a circular tube. The cross-sectional area of ​​the central tube 3 is 1 / 10 to 9 / 10 of the projected cross-section of the annular gas distribution chamber; preferably 1 / 3; the distance from the upper end of the central tube 3 to the annular gas pre-distribution chamber is 1 / 50 to 50 of its diameter; preferably, the distance from the upper end to the annular gas pre-distribution chamber 2 is 1 / 5 of its diameter.

[0028] The upper edge of the intake pipe 1 is not higher than the upper edge of the central pipe 3; the distance between the upper edge of the intake pipe 1 and the upper edge of the core is 1 / 2 of the diameter of the intake pipe 1; the intake pipe 1 can be a round pipe or a rectangular pipe, preferably a round pipe.

[0029] The microsphere catalyst spray drying tower 6 has a cylindrical body with a conical bottom and a cone angle of 15 to 50 degrees, preferably 30 degrees. A catalyst outlet 8 is located at the bottom of the cone, and a gas outlet 7 is located on the side wall of the cone. The catalyst outlet 8 is circular or rectangular. An extended colloid input mechanism 5 is installed inside the microsphere catalyst spray drying tower 6, with a slurry spray nozzle at its outlet end. The distance between the colloid input mechanism 5 and the bottom of the microsphere catalyst spray drying tower 6 is 1 / 50 to 2 of the cylinder diameter, preferably 1 / 5 of the cylinder diameter. Preferably, four centrally symmetrical colloid input mechanisms 5 are provided.

[0030] The method and principle of using a microsphere catalyst spray drying tower based on a circulating gas distribution device according to the present invention are as follows:

[0031] High-temperature gas enters the annular gas distribution chamber 2 symmetrically through the tangential inlet pipe 1, wherein the temperature of the high-temperature gas is set at 450~650°C. o C; inlet linear velocity 5~25m / s; relative humidity 0.1~25%; preferred temperature 500℃. o C; Inlet linear velocity is 20 m / s; Relative humidity is 5%.

[0032] High-temperature gas symmetrically enters the annular gas distribution chamber 2 through the tangential inlet pipe 1. After swirling upwards and reversing, it exits through the central pipe 3, passes through the gas distribution device 4, and then contacts the microsphere catalyst slurry from the colloidal input mechanism 5. The FCC catalyst slurry enters the microsphere catalyst spray drying tower from the slurry nozzle of the colloidal input mechanism 5 to complete the spray drying process, thus obtaining the FCC catalyst. Under the action of gravity, gas-solid separation is achieved, and the gas and catalyst particles are discharged separately from the bottom cone of the microsphere catalyst spray drying tower.

[0033] In the microsphere catalyst spray drying tower, to ensure uniform gas distribution, the pressure drop of the high-temperature gas through the circulating gas distribution device is 1 / 20 to 1 / 2 of the pressure drop at the inlet and outlet of the spray tower.

[0034] Preferably, the pressure drop of the high-temperature gas through the circulating gas distribution device is 1 / 5 of the pressure drop at the inlet and outlet of the spray tower.

[0035] This invention ensures a uniform and reasonable distribution of temperature and hot air within the spray drying tower. It effectively prevents problems such as uneven hot air distribution and hot air deviation within the drying tower, avoids back-mixing of wet catalyst particles, particle adhesion, and tower sticking, thereby effectively controlling product sphericity, particle adhesion, and particle size distribution, and improving the fluidization state and reaction performance of the FCC catalyst.

Claims

1. A microsphere catalyst spray drying tower based on a circulating gas distribution device, characterized in that, The system includes a microsphere catalyst spray drying tower (6), the top of which is fixed with a circulating gas distribution device. The circulating gas distribution device includes an annular gas distribution chamber (2), which is sealed at the top and bottom. The annular gas distribution chamber (2) is connected to an inlet pipe (1). There are two inlet pipes (1), which are symmetrically and tangentially connected to the annular gas distribution chamber (2). A central pipe (3) is also fixed at the bottom of the annular gas distribution chamber (2). The central pipe (3) extends upward from the bottom of the annular gas distribution chamber (2) and is connected to a gas distribution device (4). The gas distribution device (4) is installed inside the microsphere catalyst spray drying tower (6) and the gas... The volume distribution device (4) is located below the annular gas distribution chamber (2); the microsphere catalyst spray drying tower (6) has a cylindrical body, and a catalyst outlet (8) is provided at the bottom of the microsphere catalyst spray drying tower (6). An extended colloidal input mechanism (5) is provided inside the cylinder of the microsphere catalyst spray drying tower (6); the bottom of the microsphere catalyst spray drying tower (6) is a cone, and the catalyst outlet (8) is located at the bottom of the cone. A gas outlet (7) is provided on the side wall of the cone; high temperature gas enters the annular gas distribution chamber (2) symmetrically through the tangential gas inlet pipe (1), and after swirling back from bottom to top, it is discharged from the central pipe (3) and passes through the gas distribution device (4) to contact the microsphere catalyst slurry from the colloidal input mechanism (5).

2. The microsphere catalyst spray drying tower based on a circulating gas distribution device as described in claim 1, characterized in that, The annular gas distribution chamber (2) is a frustum, and the projected area of ​​the upper end of the frustum is 1 / 3 of the projected area of ​​the lower end; the diameter of the lower end of the annular gas distribution chamber (2) is the same as the diameter of the cylinder of the microsphere catalyst spray drying tower (6).

3. The microsphere catalyst spray drying tower based on a circulating gas distribution device as described in claim 1, characterized in that, The annular gas distribution chamber (2) is connected to the gas distribution device (4) through a perforated plate. The gas distribution device (4) is a two-stage gas distributor or a tubular distributor with an opening ratio of 0.5% to 50%.

4. The microsphere catalyst spray drying tower based on a circulating gas distribution device as described in claim 1, characterized in that, The annular gas distribution chamber (2) is connected to the gas distribution device (4) through a perforated plate. The gas distribution device (4) consists of two secondary gas distributors, and the distance between two adjacent secondary distributors is 1 / 50 to 5 of their diameter.

5. The microsphere catalyst spray drying tower based on a circulating gas distribution device as described in claim 1, characterized in that, The central tube (3) is a circular or rectangular tube, and the distance between the upper end of the central tube (3) and the annular gas distribution chamber (2) is 1 / 50 to 50 of its diameter.

6. The microsphere catalyst spray drying tower based on a circulating gas distribution device as described in claim 1, characterized in that, The central tube (3) is a circular tube, and the cross-sectional area of ​​the central tube (3) is 1 / 10 to 9 / 10 of the projected cross-section of the annular gas distribution chamber.

7. The microsphere catalyst spray drying tower based on a circulating gas distribution device as described in claim 1, characterized in that, The number of colloid input mechanisms (5) is four, arranged in a centrally symmetrical manner.

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