A spray drying tower and spray drying process

Abstract

The present invention provides a spray drying tower and a spray drying process. The spray drying tower includes a tower body, an air inlet, an air outlet pipe, a discharge port, a primary spoiler, a secondary spoiler, a uniform plate, a distribution plate, and an atomizer; the uniform plate and the distribution plate respectively include a dense opening area in the central region and a sparse opening area in the peripheral region; the air outlet pipe extends from the inverted cone section of the tower body to the outside of the tower body, and the opening of the air outlet pipe located in the inverted cone section of the tower body is located at the geometric center of the inverted cone section of the tower body; the air inlet is located at the top of the tower body, and its position is higher than the primary spoiler; the distribution plate is located higher than the outlet of the atomizer; the primary spoiler, secondary spoiler, uniform plate, and distribution plate are arranged in sequence from top to bottom. The present invention also provides a spray drying process for controlling the morphology of different types of catalytic cracking catalyst particles using the above-mentioned spray drying tower.

Description

Technical Field

[0001] The invention relates to a spray drying tower and a spray drying process, belonging to the technical field of microsphere preparation. Background Art

[0002] Spray drying is a systematic method of drying materials, encompassing various spray drying methods, including centrifugal, pressure, and two-fluid methods. Pressure spray drying, characterized by high throughput, simple construction, and low energy consumption and cost, is widely used in the ceramics, pharmaceutical, food, and chemical industries. It is also a commonly used drying and forming process in the industrial production of catalytic cracking catalysts and their additives.

[0003] Catalytic cracking catalyst is a zeolite molecular sieve microsphere catalyst, which is widely used in the catalytic cracking process in the petroleum refining link. According to the common preparation process, it can be divided into: in-situ crystallization catalyst (i.e., full clay) in which the clay matrix is ​​partially crystallized into zeolite, composite (i.e., semi-synthetic) catalysts in which the zeolite and matrix are prepared separately, and catalytic cracking adjuvants used to enhance relatively single functions. Generally, catalytic cracking catalysts and their adjuvants require the catalyst to have good particle morphology while meeting the reaction performance. The presence of irregular microsphere particles such as hollow, concave, and sticky particles affects the catalyst particle morphology and ultimately has a substantial impact on its fluidity and anti-wear performance.

[0004] During the spray drying process of catalytic cracking catalyst, liquid material is rapidly dispersed into small droplets through a high-pressure pump and an atomizer. The droplets come into contact with hot air, rapidly evaporating the water and gradually drying the particles. The solid material is collected, and the gaseous medium passes through a cyclone separator and is discharged. The spray drying process forms irregular microspheres with hollow, concave, and clumping particles. It is also a key step influencing product performance, such as particle morphology and abrasion resistance, of the catalytic cracking catalyst product.

[0005] The problem of difficult-to-control product particle morphology is common in the production process of catalytic cracking catalysts and their additives. The existing spray drying process has not optimized process control conditions such as hot air flow rate and inlet and outlet temperature difference according to the needs of different types of catalysts and their additives. As a result, the product is prone to irregular particles such as hollow depressions. At the same time, the tower structure used in the spray drying tower is difficult to adapt to the adjustment requirements of process control for different types of catalysts. Its hot air distribution device only distributes the hot air evenly vertically downward, making it difficult to flexibly control the movement direction and concentration of the hot air distribution in the tower. As a result, the drying rate of the atomized droplets in the constant-speed drying section is low, the product particles are prone to sticking to each other, and the material is prone to sticking to the wall, affecting the product particle morphology. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the object of the present invention is to provide a spray drying tower and a spray drying process, which have high drying efficiency and can flexibly adjust the spray drying process conditions to meet the requirements for controlling the particle morphology during the spray forming process of different types of catalysts, such as composite catalytic cracking catalysts, in-situ crystallization catalytic cracking catalysts, and catalytic cracking additives.

[0007] To achieve the above object, the present invention provides a spray drying tower, wherein the spray drying tower comprises a tower body, an air inlet, an air outlet, a material outlet, a primary spoiler, a secondary spoiler, a uniform distribution plate, a distribution plate, and an atomizer; wherein,

[0008] The tower body comprises a straight tube section and an inverted cone section connected to each other;

[0009] The primary spoiler, secondary spoiler, uniform distribution plate and distribution plate are arranged around the sleeve of the atomizer, and their respective edges are respectively connected to the inner wall of the tower body; the blades of the primary spoiler and the blades of the secondary spoiler are arranged perpendicularly and staggered to each other; the uniform distribution plate includes a dense opening area in the central area and a sparse opening area in the peripheral area, and the dense opening area and the sparse opening area are respectively provided with openings that pass through vertically from top to bottom; the distribution plate includes a dense opening area in the central area and a sparse opening area in the peripheral area, and the dense opening area is provided with openings that pass through vertically and are inclined toward the atomizer, and the sparse opening area is provided with openings that pass through vertically from top to bottom;

[0010] The air outlet pipe extends from the inverted cone section of the tower body to the outside of the tower body, and the opening of the air outlet pipe located in the inverted cone section of the tower body is located at the geometric center of the inverted cone section of the tower body;

[0011] The atomizer is provided at the top of the spray drying tower, and the number of the atomizer is at least one;

[0012] The discharge port is arranged at the top of the inverted cone section of the tower body;

[0013] The air inlet is arranged at the top of the tower body, and its position is higher than the primary spoiler. The distribution plate is located higher than the outlet of the atomizer. The primary spoiler, secondary spoiler, uniform distribution plate and distribution plate are arranged in sequence from top to bottom.

[0014] According to a specific embodiment of the present invention, in the above-mentioned spray drying tower, the air inlet and the atomizing nozzle are located above the tower body, and the hot air entering the spray drying tower flows downward together with the mist droplets.

[0015] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the openings in the dense opening area and the sparse opening area of ​​the uniformly distributed plate are vertical through holes, the dense opening area of ​​the distribution plate is inclined openings, and the sparse opening area is vertical through holes.

[0016] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the angle α of the inclined openings in the dense opening area of ​​the distribution plate is 0.5θ≤α≤90°, wherein the θ is the atomization angle of the atomizer; more preferably, the α is 0.5θ≤α≤75°.

[0017] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the opening rate of the uniform plate is 1-50%, and the opening rate of the distribution plate is in the range of 1-30%, and the opening rate of the uniform plate is greater than the opening rate of the distribution plate, thereby achieving a better hot air distribution effect; more preferably, the opening rate of the uniform plate is 1-40%, and the opening rate of the distribution plate is in the range of 1-20%. The openings referred to in the opening rates of the uniform plate and the distribution plate include both dense opening areas and sparse opening areas.

[0018] According to a specific embodiment of the present invention, in the above-mentioned spray drying tower, the uniform distribution plate can preferably be a conventional uniform distribution plate with uniformly distributed vertical through-holes. More preferably, a uniform distribution plate can be used with dense through-holes uniformly arranged around the atomizer sleeve and sparse through-holes uniformly arranged around the periphery. The ratio of the area of ​​the densely distributed open area of ​​the uniform distribution plate to the sparsely distributed open area of ​​the uniform distribution plate can be controlled to be 1-10:1, more preferably 1-8:1.

[0019] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the area ratio of the dense opening area of ​​the distribution plate to the sparse opening area of ​​the distribution plate is 1-10:1; more preferably 1-8:1.

[0020] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the spray drying tower further comprises a uniform distribution plate support seat and a distribution plate support seat.

[0021] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the uniform distribution plate support is fixed on the outer wall of the sleeve of the atomizer to connect the uniform distribution plate to the sleeve of the atomizer.

[0022] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the uniform distribution plate is connected to the atomizer sleeve via a support base, and the support base is of equal diameter. More preferably, the distribution plate support base is fixed to the outer wall of the atomizer sleeve to connect the distribution plate to the atomizer sleeve.

[0023] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the uniformly distributed plate support seat is cylindrical or prismatic.

[0024] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the distribution plate support seat is tapered from top to bottom. More preferably, the tapering angle of the distribution plate support seat is the same as the angle α of the inclined opening.

[0025] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the angle between the outer wall of the distribution plate support seat and the sleeve of the atomizer is 90°-α.

[0026] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the pitch of the blades of the primary spoiler is greater than the pitch of the blades of the secondary spoiler. More preferably, the pitch of the blades of the primary spoiler is 200-600 mm, the height of the primary spoiler (i.e., the thickness of the spoiler) is 2-30 mm, the pitch of the blades of the secondary spoiler is 100-300 mm, and the height of the secondary spoiler (i.e., the thickness of the spoiler) is 1-15 mm.

[0027] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the shape of the blades of the spoiler is one or more of rectangular, square or diamond shapes.

[0028] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the opening of the air outlet pipe located at the inverted cone section of the tower body is a bell mouth, and the direction of the bell mouth is vertically downward, and the opening angle β is 90-150°.

[0029] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the ratio of the vertical distance between the lower edge of the bell mouth and the lower end of the inverted cone section and the vertical distance between the lower edge of the bell mouth and the upper end of the inverted cone section is 1:(1-10).

[0030] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying tower, the atomizer includes a spray gun, a nozzle and a sleeve, the spray gun is arranged in the sleeve, the nozzle is arranged at the bottom end of the spray gun, and a spray hole is provided in the nozzle.

[0031] According to a specific embodiment of the present invention, preferably, the spray drying tower includes more than two atomizers, and each atomizer is provided with a dense opening area around it, and sparse opening areas are evenly arranged around the dense opening area.

[0032] According to a specific embodiment of the present invention, the dense openings refer to a large number of openings per unit area with a dense distribution of holes, and the sparse openings refer to a small number of openings per unit area with a sparse distribution. The shapes of the dense openings and the sparse openings can be one or more of circular, elliptical, trapezoidal or concentric arcs, and the opening diameters can be one or more of the following forms: equal diameters at the top and bottom, larger diameters at the top and smaller diameters at the bottom, or smaller diameters at the top and larger diameters at the bottom. The vertical through-hole refers to an opening direction perpendicular to the plate surface. The reduction angle refers to the angle between the outer side of the support seat and the sprayer sleeve.

[0033] The present invention also provides a spray drying process, which is carried out using the above-mentioned spray drying tower, and the spray drying process comprises:

[0034] Hot air enters the interior of the spray drying tower from the air inlet and passes through the primary spoiler, secondary spoiler, uniform distribution plate, and distribution plate in sequence, and then contacts the droplets formed by the atomizer, drying the droplets to obtain microspheres;

[0035] The microspheres leave the spray drying tower through a discharge port;

[0036] The hot air leaves the spray drying tower through the air outlet pipe.

[0037] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying process, the temperature of the hot air entering from the air inlet is 400°C-680°C, and the temperature of the hot air leaving from the air outlet is 80°C-200°C.

[0038] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying process, when the microspheres are a composite catalytic cracking catalyst: the temperature of the hot air entering from the air inlet is 400°C-680°C, and the temperature of the hot air leaving from the air outlet is 80°C-200°C; the flow rate of the hot air when passing through the uniform distribution plate is 0.1-0.5 m / s; the flow rate of the hot air when passing through the distribution plate is 1-10 m / s.

[0039] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying process, when the microspheres are in-situ crystallized catalytic cracking catalysts: the temperature of the hot air entering from the air inlet is 400°C-600°C, and the temperature of the hot air leaving from the air outlet is 140°C-280°C; the flow rate of the hot air when passing through the uniform distribution plate is 0.1-1m / s; the flow rate of the hot air when passing through the distribution plate is 1-20m / s.

[0040] According to a specific embodiment of the present invention, preferably, in the above-mentioned spray drying process, when the microspheres are catalytic cracking aids: the temperature of the hot air entering from the air inlet is 400°C-650°C, and the temperature of the hot air leaving from the air outlet is 120°C-200°C; the flow rate of the hot air when passing through the uniform distribution plate is 0.1-0.8 m / s; the flow rate of the hot air when passing through the distribution plate is 1-15 m / s.

[0041] The spray drying process and spray drying tower provided by the present invention can meet the spray forming requirements of various catalytic cracking catalyst microspheres. In the process of preparing the catalyst by spray drying, the droplets dispersed by the atomizer come into contact with the hot air flow, the surface temperature rises rapidly, and the water begins to vaporize and evaporate; in the constant-speed drying section, the water inside the droplets continues to migrate to the surface and continuously vaporizes and evaporates until dry spots appear on the surface of the particles; in the speed-decreasing drying section, the water inside the particles gradually decreases, the migration speed gradually slows down, and the dry shell gradually forms from the outside to the inside until the microsphere particles complete the drying process. When the drying rate is too fast, the catalyst microspheres are prone to forming a concave hollow phenomenon; when the drying rate is too slow, the catalyst microspheres are prone to forming mutual adhesion. When the drying rate is appropriate, the catalyst microspheres are easy to form spherical solid particles. Different types of catalytic cracking catalysts and catalytic cracking additives have different migration speeds of water from the inside to the outside after the droplets are formed, and have different requirements for the drying rate of the spray drying process.

[0042] The present invention provides a spray drying tower that easily adjusts the direction and concentration of hot air movement through a hot air distribution device. The outlet bell-shaped structure reduces the hot air flow rate, thereby reducing the amount of fine powder and the carryover of large particles. Furthermore, the spray drying process provided by the present invention can adjust the drying rate during particle drying by controlling the tower inlet temperature, tower outlet temperature, hot air flow rate, and the concentration and direction of movement of the hot air flow when it impacts droplets. This prevents the occurrence of hollow, concave, and sticky particles in the catalyst microspheres during the spray forming process due to differences in water migration rates between different catalyst types, thereby meeting the requirements for microsphere particle forming.

[0043] The spray drying process and spray drying tower provided by the present invention are suitable for the spray forming of different types of catalytic cracking catalysts, such as composite catalytic cracking catalysts, in-situ crystallization catalytic cracking catalysts and catalytic cracking additives. They are easy to control the morphology of product particles, effectively reduce the occurrence of hollow, concave and sticky particles, and have the characteristics of high product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of a pressure spray drying tower using a single atomizer provided in an embodiment of the present invention;

[0045] Figure 2 A schematic structural diagram of a hot air distribution device in a spray drying tower provided in an embodiment of the present invention;

[0046] Figure 3 Schematic diagram of the opening angle α of the inclined through-holes on the distribution plate;

[0047] Figure 4 Schematic diagram of the nozzle centerline and atomization angle θ of the atomizer;

[0048] Figure 5 is a schematic diagram of an embodiment of a bell mouth;

[0049] Figure 6 A schematic diagram of a pressure spray drying tower using multiple atomizers provided in an embodiment of the present invention;

[0050] Figure 7 This is a comparison chart of the implementation effects of preparing the composite catalytic cracking catalyst in Example 1 and Comparative Example 1;

[0051] Figure 8 This is a comparison chart of the implementation effects of preparing in-situ crystallization catalytic cracking catalysts in Example 3 and Comparative Example 2;

[0052] Figure 9 This is a comparison chart of the implementation effects of preparing catalytic cracking aids in Example 5 and Comparative Example 3.

[0053] Marking Description:

[0054] 1 Drying tower; 101 Straight cylinder section; 102 Inverted cone section; 2 Air inlet; 3 Air outlet duct; 301 Hot air outlet; 4 Discharge port; 5 Hot air distribution device; 501 Primary spoiler; 502 Secondary spoiler; 503 Uniform distribution plate; 504 Distribution plate; 5051 Sparse open hole area; 5061 Dense open hole area; 5052 Sparse open hole area; 5062 Dense open hole area; 507 Uniform distribution plate support; 508 Distribution plate support; 6 Atomizer; 601 Atomizer nozzle; 602 Spray hole; 603 Atomizer spray hole centerline; 604 Casing. DETAILED DESCRIPTION

[0055] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0056] The embodiment of the present invention provides a hot air distribution device, which is applied to a spray drying tower 1 provided with at least one atomizer, Figure 2 As shown, it includes a primary spoiler 501, a secondary spoiler 502, a uniform distribution plate 503 and a distribution plate 504 arranged in sequence from top to bottom;

[0057] The primary spoiler 501, the secondary spoiler 502, the uniform distribution plate 503 and the distribution plate 504 are respectively arranged around the sleeve 604 of the atomizer 6, and their edges are respectively connected to the inner wall of the tower bottom;

[0058] The blades of the primary spoiler 501 and the secondary spoiler 502 are arranged vertically and staggered with each other;

[0059] The uniformly distributed plate 503 includes a densely distributed plate opening area 5061 arranged in the central area and a sparsely distributed plate opening area 5051 arranged in the peripheral area. The openings of the densely distributed plate opening area 5061 and the sparsely distributed plate opening area 5051 are all vertical through holes.

[0060] The distribution plate 504 includes a dense opening area 5062 of the distribution plate arranged around the position of its through holes and a sparse opening area 5052 of the distribution plate arranged outside the dense opening area 5062 of the distribution plate. The openings of the dense opening area 5062 of the distribution plate are inclined through holes, and the opening direction of the inclined through holes is toward the center line of the through holes. The openings of the sparse opening area 5052 of the distribution plate are vertical through holes.

[0061] The embodiment of the present invention provides a spray drying tower, wherein the hot air distribution device 5 is distributed between the air inlet 2 and the atomizer 6 in the spray drying tower 1. Figure 1 、 Figure 2 、 Figure 5 As shown, the hot air distribution device 5 can be arranged between the air inlet 2 and the atomizer 6 of the spray drying tower 1. For example, when the air inlet 2 is arranged at the upper part of the spray drying tower 1 and the atomizer 6 is arranged above the tower body, that is, the atomizing nozzle 601 of the atomizer 6 is located at the upper part of the tower body, since the hot air and the spray droplets flow downward in parallel, the hot air distribution device 5 can be arranged at the upper part of the drying tower, in the area between the air inlet 2 and the atomizing nozzle 601 of the atomizer 6, that is, the hot air distribution device 5 is located below the air inlet 2 and above the atomizing nozzle 601 of the atomizer 6. The hot air flow entering through the air inlet 2 passes through the evenly arranged primary spoiler 501 and secondary spoiler 502 in sequence, and contacts the uniform distribution plate 503. Part of the hot air flow passes through the dense opening area 5061 and is concentratedly distributed around the atomizer sleeve 604. The remaining part of the air flow passes through the sparse opening area 5051. The concentrated hot air flow passes through the dense opening area 5061 on the distribution plate 504 and is deflected at an angle α toward the center line 603 of the atomizer nozzle. The remaining part of the air flow passes through the sparse opening area 5062 and maintains vertical motion.

[0062] Reference Figure 1 、 Figure 2As shown, the spray drying tower 1 also includes a tower body, an air inlet 2, an air outlet pipe 3 and a discharge port 4, wherein the atomizer 6 is inserted from the sleeve 604, and the hot air distribution device 5 is located in the area between the air inlet 2 and the atomizing nozzle 601 of the atomizer 6. The tower body includes a straight cylindrical section 101 and an inverted cone section 102, and the air outlet pipe 3 is provided with a hot air outlet.

[0063] Of course, in an embodiment of the present invention, if the air inlet 2 of the spray dryer is arranged at the lower part of the spray drying tower, and the atomizer 6 is arranged below the tower body, that is, the atomizing nozzle 601 of the atomizer 6 is located at the lower part of the tower body, since the hot air and the spray droplets flow upward in parallel, the hot air distribution device 5 can be arranged at the lower part of the drying tower, in the area between the air inlet 2 and the atomizing nozzle 601 of the atomizer 6, that is, the hot air distribution device 5 is located above the air inlet 2 and below the atomizing nozzle 601 of the atomizer 6.

[0064] The specific implementation of the spray drying tower provided in the embodiments of the present invention can be referenced to the detailed description of the hot air distribution device 5 in the above embodiments, and any repetitive details will be omitted. The specific structure and implementation of the tower body, air inlet 2, air outlet pipe 3, discharge port 4, and atomizer 6 in the above-mentioned spray drying tower can be determined by those skilled in the art by reference to the description in the prior art, and the present invention does not limit them.

[0065] The dense opening area 5061 of the uniformly distributed plate and the sparse opening area 5051 of the uniformly distributed plate are corresponding concepts, wherein the dense opening area refers to an opening area with many openings per unit area and a dense distribution of holes, and the sparse opening area refers to an opening area with few openings per unit area and a sparse distribution of holes. The dense opening area 5062 of the distribution plate and the sparse opening area 5052 of the distribution plate are also corresponding concepts, and the difference in openings between the two is similar to that between the dense opening area 5061 of the uniformly distributed plate and the sparse opening area 5051 of the uniformly distributed plate. The vertical through holes on the uniformly distributed plate and the distribution plate refer to openings whose opening direction is perpendicular to the plate surface, that is, the central axis of the vertical through hole is perpendicular to the uniformly distributed plate 503 and the distribution plate 504.

[0066] In the embodiment of the present invention, when the hot air distribution device 5 is arranged in the spray drying tower, the center line of the primary spoiler 501, the secondary spoiler 502, the uniform distribution plate 503 and the distribution plate 504 coincides with the center line of the nozzle 602 of the atomizer 6. Figure 4 As shown, a spray hole 602 is centrally located in the atomizer 6 of the spray drying tower. The geometric centerline of the spray hole 602 is the atomizing hole centerline 603. Under pressure, the liquid is ejected from the spray hole 602, forming a conical droplet group with a maximum opening angle, which is the atomization angle θ.

[0067] In the embodiment of the present invention, the above-mentioned secondary spoiler 502 is connected to the primary spoiler 501 and the uniform plate 503 respectively, and the primary spoiler 501, the secondary spoiler 502, the uniform plate 503 and the distribution plate 504 are all suitable for being connected to the inner wall of the tower body of the spray-drying tower. In the embodiment of the present invention, the specific implementation of the connection of the secondary spoiler 502 with the primary spoiler 501 and the uniform plate 503, and the specific implementation of the connection of the primary spoiler 501, the secondary spoiler 502, the uniform plate 503 and the distribution plate 504 with the inner wall of the tower body of the spray-drying tower can also be referred to the detailed description in the prior art. In the present embodiment, no specific limitation is made to this.

[0068] In the embodiment of the present invention, the corresponding positions of the primary spoiler 501, the secondary spoiler 502, the uniform distribution plate 503 and the distribution plate 504 of the hot air distribution device 5 can be respectively provided with one through hole or multiple through holes to adapt to the specific structure of the spray drying tower. Figure 1 and Figure 2 As shown, when the spray drying tower is provided with an atomizer 6, a through hole is provided at the corresponding positions of the primary spoiler 501, the secondary spoiler 502, the uniform distribution plate 503 and the distribution plate 504, respectively, to allow the sleeve 604 of the atomizer 6 to pass through; Figure 2 、 Figure 5 、 Figure 6 As shown, when the spray drying tower is provided with a plurality of atomizers 6, corresponding positions of the primary spoiler 501, the secondary spoiler 502, the uniform distribution plate 503 and the distribution plate 504 are respectively provided with a corresponding number of through holes allowing the sleeves 604 of the atomizers 6 to pass through. Moreover, when a plurality of atomizers 6 are provided in the spray drying tower, in the embodiment of the present invention, the uniform distribution plate 503 and the distribution plate 504 are respectively provided with a corresponding number of dense opening areas 5061 of the uniform distribution plate and a plurality of dense opening areas 5062 of the distribution plate around the sleeves 604 of the atomizers 6, while the sparse opening areas 5051 of the uniform distribution plate are provided around the dense opening areas 5061 of the uniform distribution plate 503, and the sparse opening areas 5052 of the distribution plate are provided around the dense opening areas 5062 of the distribution plate 504.

[0069] The hot air distribution device 5 provided in the embodiment of the present invention is provided in a spray drying tower. When the primary spoiler 501, the secondary spoiler 502, the uniform distribution plate 503 and the distribution plate 504 are connected to the inner wall of the tower body, and the spray sleeve of the atomizer 6 passes through the center of the primary spoiler 501, the secondary spoiler 502, the uniform distribution plate 503 and the distribution plate 504 in sequence. During the spray forming process, the hot air flow enters the tower body from the air inlet 2 of the spray drying tower, first contacts the primary spoiler 501 and the secondary spoiler 502, and forms a grid structure through the vertical staggered arrangement of the blades of the primary spoiler 501 and the secondary spoiler 502, thereby better exerting the spoiling effect. The primary spoiler 501 and the secondary spoiler 502 disturb the direction of the air flow, forming a large number of vortices and swirls, thereby improving the uniformity of the hot air distribution in the tower and avoiding the overall deviation of the hot air flow inside the tower body. Next, the evenly distributed hot air flow contacts the uniform distribution plate 503. When the hot air flow passes through the uniform distribution plate 503, it passes through the vertical through-holes 1033 on the uniform distribution plate 503, so that the hot air flow keeps moving in the vertical direction. Since the dense opening area 5061 of the uniform distribution plate 503 has more openings than the sparse opening area 5051 and the openings are densely distributed, the hot air flow around the sleeve 604 of the atomizer 6 is easier to pass through the uniform distribution plate 503, so that the hot air flow is concentratedly distributed around the sleeve 604 of the atomizer 6. Next, the hot air flow passing through the distribution plate 504 contacts the distribution plate 504. When the hot air flow passes through the distribution plate 504, due to the distribution plate 504 The dense opening area 5062 of the distribution plate has more openings than the sparse opening area 5052 of the distribution plate and the openings are densely distributed, which can further ensure that the hot air flow is concentratedly distributed around the atomizer 6. Since the openings in the dense opening area 5062 of the distribution plate are inclined through holes, the hot air flow close to the atomizer 6 contacts the droplet group dispersed by the atomizer 6 at a certain inclination angle, thereby enhancing the impact drying effect and quickly completing the droplet drying; and the hot air flow passing through the vertical through holes of the sparse opening area 5052 of the distribution plate 504 always keeps moving in the vertical direction to maintain a relatively uniform air flow distribution in the tower body, thereby avoiding material sticking to the wall.

[0070] In one embodiment, referring to Figure 3 The opening angle α of the inclined through hole is 0.5θ≤α≤90°, wherein θ is the atomization angle of the atomizer 6 .

[0071] Reference Figure 4 As shown, when the atomizer 6 atomizes the liquid to be atomized, pressure is applied to cause atomized droplets to be ejected from the atomizing nozzle 601 through the atomizing channel. The atomized droplets are dispersed from the nozzle orifice 602 to form a droplet cluster. The atomizing nozzle 601 can be pre-configured to control the maximum opening angle of the conical droplet cluster, which is the atomization angle of the atomizer 6 and is denoted by θ. The atomization angle θ can be set according to actual production needs and is not specifically limited thereto.

[0072] In the embodiment of the present invention, referring to Figure 3 As shown, the opening angle α of the inclined through hole can be understood as the angle formed by the opening direction of the inclined through hole of the distribution plate 504 and the plane where the distribution plate 504 is located. Specifically, it can be the angle between the center line of the inclined through hole and the plane where the distribution plate 504 is located. In the embodiment of the present invention, the hot air flow is uniformly and concentratedly distributed around the atomizer 6 by adjusting the hot air distribution direction inside the spray drying tower. When the hot air flow contacts the distribution plate 504, the hot air flow concentratedly distributed around the atomizer 6 contacts the droplet group dispersed by the atomizer 6 at an angle α, so that the atomized droplet group immediately contacts the large amount of hot air flow distributed at the angle α, further accelerating the evaporation rate of the water on the droplet surface and quickly forming a drying shell layer, avoiding mutual adhesion between material particles, and completing the drying process before the material particles contact the tower wall, which is conducive to further reducing the phenomenon of material particles sticking to the wall.

[0073] In one embodiment, the porosity of the uniform distribution plate 503 is 1-50%, the porosity of the distribution plate 504 is 1-30%, and the porosity of the uniform distribution plate 503 is greater than that of the distribution plate 504.

[0074] In an embodiment of the present invention, the porosity of the uniform distribution plate 503 is greater than the porosity of the distribution plate 504. When the hot air flow passes through the uniform distribution plate 503 and the distribution plate 504, the opening area of ​​the uniform distribution plate 503 is large, while the opening area of ​​the uniform distribution plate 503 becomes smaller, so that the movement speed of the hot air flow through the uniform distribution plate 503 is lower than the movement speed of the hot air flow through the distribution plate 504, so that the hot air flow can contact the droplet group dispersed by the atomizer 6 at a higher speed, thereby enhancing the impact drying effect and accelerating the droplet drying speed.

[0075] In a specific embodiment, the above-mentioned uniform distribution plate 503 is configured to be suitable for the air to flow through the vertical through-holes at a speed of 0.1-1m / s, and the distribution plate 504 is configured to be suitable for the air to flow through the vertical through-holes and the inclined through-holes at a speed of 1-20m / s. When the hot air distribution device 5 provided in the embodiment of the present invention is applied to a spray drying tower, those skilled in the art can adjust the speed of the hot air flow through the openings of the uniform distribution plate 503 and the distribution plate 504 by adjusting the hot air flow rate of the air inlet 2 of the spray drying tower. By adjusting the hot air movement speed inside the spray drying tower, the hot air flow passes through the distribution plate 504 at a speed of 1-20m / s, which greatly improves the drying rate of the droplets, shortens the drying time of the droplets in the constant speed drying section, speeds up the droplet drying process, and further reduces the phenomenon of material particles adhering to the tower wall. In the embodiment of the present invention, the method for adjusting the speed of the hot air flow through the uniform distribution plate 503 and the distribution plate 504 can refer to the detailed description in the prior art. In the embodiment of the present invention, no specific limitation is made to this.

[0076] As a specific implementation of an embodiment of the present invention, the uniform distribution plate 503 can be set to be suitable for the air flowing through the vertical through holes at a speed of 0.1-0.8 m / s, and the distribution plate 504 can be set to be suitable for the air flowing through the vertical through holes and the inclined through holes at a speed of 1-15 m / s.

[0077] In a specific embodiment, the opening rate of the uniform distribution plate 503 is 1-40%, and the opening rate of the distribution plate 504 is in the range of 1-20%.

[0078] In a specific embodiment, the area ratio of the dense opening area 5061 of the uniformly distributed plate to the sparse opening area 5051 of the uniformly distributed plate is 1 to 10; the area ratio of the dense opening area 5062 of the distribution plate to the sparse opening area 5052 of the distribution plate is 1 to 10.

[0079] In the embodiment of the present invention, by setting the area ratio of the dense opening area 5061 of the uniform distribution plate to the sparse opening area 5051 of the uniform distribution plate, and the area ratio of the dense opening area 5062 of the distribution plate to the sparse opening area 5052 of the distribution plate, the opening rate setting of the dense opening area and the sparse opening area of ​​the uniform distribution plate 503 and the distribution plate 504 is achieved, thereby adjusting the air flow rate of the hot air flow in the dense opening area and the sparse opening area, so that the hot air flow is concentrated around the sleeve 604 of the atomizer 6.

[0080] In a specific embodiment, the vertical through holes in the dense opening area 5061 of the uniformly distributed plate and the sparse opening area 5051 of the uniformly distributed plate, as well as the inclined through holes in the dense opening area 5062 of the distribution plate and the vertical through holes in the sparse opening area 5052 of the distribution plate are all evenly arranged openings. By uniformly arranging the vertical through holes in the dense opening area 5061 of the uniformly distributed plate and the sparse opening area 5051 of the uniformly distributed plate, it is ensured that when the uniformly distributed hot air flow passing through the primary spoiler 501 and the secondary spoiler 502 contacts the uniformly distributed plate 503, the hot air flow in the dense opening area 5061 of the uniformly distributed plate and the sparse opening area 5051 of the uniformly distributed plate can still be evenly distributed in the corresponding area; at the same time, by uniformly arranging the inclined through holes and vertical through holes in the dense opening area 5062 of the distribution plate and the sparse opening area 5052 of the distribution plate, it is ensured that when the hot air flow passing through the uniformly distributed plate 503 contacts the distribution plate 504, the hot air flow in the dense opening area 5062 of the distribution plate and the sparse opening area 5052 of the distribution plate can also be evenly distributed in the corresponding area.

[0081] In one embodiment, referring to Figure 2 As shown, the hot air distribution device further includes a uniform distribution plate support seat 507 and a distribution plate support seat 508;

[0082] The uniform distribution plate support seat 507 is suitable for being fixed to the sleeve 604 of the atomizer 6 to connect the uniform distribution plate 503 with the sleeve 604 of the atomizer 6;

[0083] The distribution plate support seat 508 is suitable for being fixed to the sleeve 604 of the atomizer 6 to connect the distribution plate 504 with the sleeve 604 of the atomizer 6 .

[0084] In an embodiment of the present invention, the uniform distribution plate support seat 507 and the distribution plate support seat 508 are respectively fixed to the sleeve 604 of the atomizer 6 of the atomizer 6, and the uniform distribution plate 503 and the distribution plate 504 can be respectively connected to the sleeve 604 of the atomizer 6 of the atomizer 6.

[0085] In one embodiment, referring to Figure 2 As shown, the uniform distribution plate support seat 507 is cylindrical or prismatic in shape; the distribution plate support seat 508 is in a shape with a decreasing diameter from top to bottom.

[0086] In one embodiment, referring to Figure 2 As shown, the angle between the outer wall of the distribution plate support 508 and the spray sleeve of the atomizer 6 is 90°-α. By setting the reduction angle of the distribution plate support 508 to be the same as the opening direction α of the inclined through hole, that is, the inclination direction of the distribution plate support 508 is consistent with the direction of hot air flow, the formation of vortices below the support can be avoided, which would affect the drying efficiency of the spray drying tower.

[0087] In one embodiment, referring to Figure 2 As shown, the pitch of the blades of the primary spoiler 501 is greater than the pitch of the blades of the secondary spoiler 502. In the embodiment of the present invention, by setting the pitch of the blades of the primary spoiler 501 to be greater than the pitch of the blades of the secondary spoiler 502, the blades of the secondary spoiler 502 are relatively denser, thereby evenly distributing the hot air flow passing through the secondary spoiler 502.

[0088] In one embodiment, referring to Figure 2 As shown, the height of the primary spoiler 501 is greater than the height of the secondary spoiler 502. In the embodiment of the present invention, by setting the height of the primary spoiler 501 to be greater than the height of the secondary spoiler 502, the airflow direction of the thermal airflow is changed, and the spoiler effect of the primary spoiler 501 and the secondary spoiler 502 is better exerted.

[0089] In a specific embodiment, the pitch of the blades of the primary spoiler 501 may be 200-600 mm, the height of the primary spoiler 501 may be 2-30 mm, the pitch of the blades of the secondary spoiler 502 may be 100-300 mm, and the height of the secondary spoiler 502 may be 1-15 mm. In the embodiment of the present invention, the pitch of the blades of the primary spoiler 501 and the secondary spoiler 502, as well as the height of the primary spoiler 501 and the secondary spoiler 502, may be reasonably selected by those skilled in the art based on the corresponding pitch ranges and height ranges to meet actual production requirements.

[0090] In order to facilitate further understanding of the present invention, the following specific examples and comparative examples of the spray drying process are provided. The spray drying tower used in the following examples and comparative examples is a pressure-type spray drying tower with a diameter of 2 meters. The specific structure of the spray drying tower used in the examples and the structure of the hot air distribution device 5 are as follows: Figure 1-Figure 2 As shown, where:

[0091] The air inlet 2 is arranged at the upper part of the spray drying tower;

[0092] A single atomizer 6 is vertically inserted into the tower body from the center of the tower top through the atomizer sleeve 604. The outer diameter of the sleeve 604 of the atomizer 6 is 80 mm. The atomizer 6 is located 250 mm below the air inlet 2. The nozzle 602 has a diameter of 1 mm, an atomization angle of 60°, and an atomization pressure of 5.5 MPa.

[0093] The hot air distribution device 5 is located in the area between the air inlet 2 and the atomizing nozzle 601 of the atomizer 6, and the hot air and the spray droplets flow downward in parallel.

[0094] The following comparative examples and embodiments were subjected to spray forming tests under different spray drying inlet temperatures and tail gas temperatures. After the tests, the test phenomena of material sticking to the wall were observed, and the product performance was determined based on the test results.

[0095] The product performance testing method of the present invention includes a particle size distribution testing method and a product yield calculation method, which are specifically as follows:

[0096] (1) Product particle size distribution test method: The particle size distribution is tested using a Malvern 2000MU laser particle size analyzer, using the standard GB / T-19077-2016;

[0097] (2) Determination of catalyst wear resistance: A certain amount of catalyst is placed in a fixed device and blown for 5 hours under a constant airflow. Except for the first hour, the average wear percentage in the last four hours is called the catalyst wear index, and the unit is % per hour.

[0098] (3) Calculation method of product yield: mass of sample below the tower / mass of sample on dry basis × 100%.

[0099] Comparative Example 1

[0100] This comparative example uses 10 kg of composite catalytic cracking catalyst industrial slurry (solid content 35%) to conduct a spray molding test, wherein:

[0101] The hot air inlet temperature is 500℃ and the outlet temperature is 120℃.

[0102] The spray drying tower uses a conventional hot air distribution device, which is installed 10 mm below the air inlet. The conventional hot air distribution device is not equipped with a spoiler. The uniform distribution plate and the distribution plate are respectively provided with evenly distributed vertical through holes with a hole diameter of 10 mm. The opening rate of the uniform distribution plate is 30%, and the opening rate of the distribution plate is 10%. The uniform distribution plate and the distribution plate are connected to the atomizer sleeve through an equal-diameter support base with an outer diameter of 120 mm and a height of 30 mm.

[0103] The hot air outlet is not equipped with a bell mouth.

[0104] The test phenomena, i.e. the product performance test results, are shown in Table 1.

[0105] Comparative Example 2

[0106] This comparative example uses 10 kg of in-situ crystallization type catalytic cracking catalyst industrial slurry (solid content 36%) to conduct a spray forming test, wherein:

[0107] The hot air inlet temperature is 550℃ and the outlet temperature is 160℃.

[0108] The spray drying tower uses a conventional hot air distribution device, which is installed 10 mm below the air inlet. The conventional hot air distribution device is not equipped with a spoiler. The uniform distribution plate and the distribution plate are respectively provided with evenly distributed vertical through holes with a hole diameter of 10 mm. The opening rate of the uniform distribution plate is 30%, and the opening rate of the distribution plate is 10%. The uniform distribution plate and the distribution plate are connected to the atomizer sleeve through an equal-diameter support base with an outer diameter of 120 mm and a height of 30 mm.

[0109] The hot air outlet is not equipped with a bell mouth.

[0110] The test phenomena, i.e. the product performance test results, are shown in Table 1.

[0111] Comparative Example 3

[0112] This comparative example uses 10 kg of catalytic cracking additive industrial slurry (solid content 40%) to conduct a spray molding test, wherein:

[0113] The hot air inlet temperature is 600℃ and the outlet temperature is 200℃.

[0114] The spray drying tower uses a conventional hot air distribution device, which is installed 10 mm below the air inlet. The conventional hot air distribution device is not equipped with a spoiler. The uniform distribution plate and the distribution plate are respectively provided with evenly distributed vertical through holes with a hole diameter of 10 mm. The opening rate of the uniform distribution plate is 30%, and the opening rate of the distribution plate is 10%. The uniform distribution plate and the distribution plate are connected to the atomizer sleeve through an equal-diameter support base with an outer diameter of 120 mm and a height of 30 mm.

[0115] The hot air outlet is not equipped with a bell mouth.

[0116] The test phenomena, i.e. the product performance test results, are shown in Table 1.

[0117] Example 1

[0118] The spray drying process provided in this embodiment uses 10 kg of industrial slurry of composite catalytic cracking catalyst (solid content 35%), wherein:

[0119] The hot air inlet temperature is 450℃ and the outlet temperature is 100℃.

[0120] The hot air distribution device 5 of the spray drying tower 1 is installed 10 mm below the air inlet 2, with the hot air flow rate of the uniform distribution plate 503 being 0.4 m / s and the hot air flow rate of the distribution plate 504 being 7 m / s;

[0121] The primary spoiler 501 has a blade spacing of 200 mm and a height of 20 mm; the secondary spoiler 502 has a blade spacing of 100 mm and a height of 10 mm; the primary spoiler 501 is connected to the secondary spoiler 502, and the secondary spoiler 502 is connected to the upper surface of the uniformly distributed plate 503;

[0122] The uniformly distributed plate 503 is installed about 10 mm lower than the air inlet 2, with an opening rate of 40%, an aperture of 10 mm, and an area ratio of the sparse opening area 5051 to the dense opening area 5061 of 1:5;

[0123] The distribution plate 504 is installed about 150 mm lower than the uniform distribution plate 503, with an opening rate of 10%, an aperture of 10 mm, an area ratio of the sparse opening area 5052 to the dense opening area 5062 of 1:5, and an opening angle α of the distribution plate 504 of 75°.

[0124] The outer diameters of the connection parts of the support bases 507, 508, the uniform distribution plate 503 and the distribution plate 504 are 120 mm respectively, and the diameter reduction angle of the support base 508 of the distribution plate 504 is 25°;

[0125] The hot air outlet 301 is provided with a bell mouth, the bell mouth angle β=100°, and the ratio of the vertical distance from the lower end of the bell mouth to the lower end of the inverted cone section 102 to the vertical distance from the lower end of the bell mouth to the upper end of the inverted cone section 102 (i.e. the junction of the straight cylinder section 101 and the inverted cone section 102) is 1:3.

[0126] The test phenomena, i.e. the product performance test results, are shown in Table 1.

[0127] Example 2

[0128] The spray drying process provided in this embodiment uses 10 kg of industrial slurry of composite catalytic cracking catalyst (solid content 35%), wherein:

[0129] The hot air inlet temperature is 650℃ and the outlet temperature is 180℃.

[0130] The hot air distribution device 5 of the spray drying tower 1 is installed 10 mm below the air inlet 2, with the hot air flow rate of the uniform distribution plate 503 being 0.2 m / s and the hot air flow rate of the distribution plate 504 being 3 m / s;

[0131] The primary spoiler 501 has a blade spacing of 400 mm and a height of 5 mm; the secondary spoiler 502 has a blade spacing of 250 mm and a height of 2 mm; the primary spoiler 501 is connected to the secondary spoiler 502, and the secondary spoiler 502 is connected to the upper surface of the uniformly distributed plate 503;

[0132] The installation position of the uniformly distributed plate 503 is about 10 mm lower than the air inlet 2, the opening rate is 40%, the aperture is 10 mm, and the area ratio of the sparse opening area 5051 to the dense opening area 5061 is 1:8.

[0133] The distribution plate 504 is installed about 150 mm lower than the uniform distribution plate 503, with an opening rate of 10%, an aperture of 10 mm, an area ratio of the sparse opening area 5052 to the dense opening area 5062 of 1:5, and an opening angle α of the distribution plate 504 of 30°.

[0134] The outer diameters of the connection parts of the support bases 507, 508, the uniform distribution plate 503 and the distribution plate 504 are 120 mm respectively, and the diameter reduction angle of the support base 508 of the distribution plate 504 is 60°;

[0135] The hot air outlet 301 is provided with a bell mouth, the bell mouth angle β=90°, and the ratio of the vertical distance from the lower end of the bell mouth to the lower end of the inverted cone section 102 to the vertical distance to the upper end of the inverted cone section 102 is 1:6.

[0136] The test phenomena, i.e. the product performance test results, are shown in Table 1.

[0137] Example 3

[0138] The spray drying process provided in this embodiment uses 10 kg of in-situ crystallization type catalytic cracking catalyst industrial slurry (solid content 35%), wherein:

[0139] The hot air inlet temperature is 450℃ and the outlet temperature is 150℃.

[0140] The hot air distribution device 5 of the spray drying tower 1 is installed 10 mm below the air inlet, with the hot air flow rate of the uniform distribution plate 503 being 0.5 m / s and the hot air flow rate of the distribution plate 504 being 8 m / s;

[0141] The primary spoiler 501 has a blade spacing of 250mm and a height of 10mm; the secondary spoiler 502 has a blade spacing of 150mm and a height of 5mm. The primary spoiler 501 is connected to the secondary spoiler 502, which is connected to the upper surface of the uniform distribution plate 503.

[0142] The installation position of the uniformly distributed plate 503 is about 10 mm lower than the air inlet 2, with an opening rate of 30%, an aperture of 10 mm, and an area ratio of the sparse opening area 5051 to the dense opening area 5061 of 1:8;

[0143] The distribution plate 504 is installed about 150 mm lower than the uniform distribution plate 503, with an opening ratio of 15%, an aperture of 10 mm, an area ratio of the sparse opening area 5052 to the dense opening area 5062 of 1:5, and an opening angle α of the distribution plate 504 of 45°.

[0144] The outer diameters of the connection parts of the support bases 507, 508, the uniform distribution plate 503 and the distribution plate 504 are 120 mm respectively, and the diameter reduction angle of the support base 508 of the distribution plate 503 is 45°;

[0145] The hot air outlet 301 is provided with a bell mouth, the bell mouth angle β=130°, and the ratio of the vertical distance from the lower end of the bell mouth to the lower end of the inverted cone section 102 to the vertical distance to the upper end of the inverted cone section 102 is 1:8.

[0146] The test phenomena, i.e. the product performance test results, are shown in Table 1.

[0147] Example 4

[0148] The spray drying process provided in this embodiment uses 10 kg of in-situ crystallization type catalytic cracking catalyst industrial slurry (solid content 35%), wherein:

[0149] The hot air inlet temperature is 550℃ and the outlet temperature is 250℃.

[0150] The hot air distribution device 5 of the spray drying tower 1 is installed 10 mm below the air inlet 2, with the hot air flow rate of the uniform distribution plate 503 being 0.8 m / s and the hot air flow rate of the distribution plate 504 being 15 m / s;

[0151] The primary spoiler 501 has a blade spacing of 200 mm and a height of 20 mm; the secondary spoiler 502 has a blade spacing of 100 mm and a height of 10 mm; the primary spoiler 501 is connected to the secondary spoiler 502, and the secondary spoiler 502 is connected to the upper surface of the uniformly distributed plate 503;

[0152] The installation position of the uniformly distributed plate 503 is about 10 mm lower than the air inlet 2, with an opening rate of 30%, an aperture of 10 mm, and an area ratio of the sparse opening area 5051 to the dense opening area 5061 of 1:8;

[0153] The distribution plate 504 is installed about 150 mm lower than the uniform distribution plate 503, with an opening rate of 20%, an aperture of 10 mm, an area ratio of the sparse opening area 5052 to the dense opening area 5062 of 1:8, and an opening angle α of the distribution plate 504 of 30°.

[0154] The outer diameters of the connection parts of the support bases 507, 508, the uniform distribution plate 503 and the distribution plate 504 are 120 mm respectively, and the diameter reduction angle of the support base 508 of the distribution plate 504 is 60°;

[0155] The hot air outlet 301 is provided with a bell mouth, the bell mouth angle β=100°, and the ratio of the vertical distance from the lower end of the bell mouth to the lower end of the inverted cone section 102 to the vertical distance to the upper end of the inverted cone section 102 is 1:6.

[0156] The test phenomena, i.e. the product performance test results, are shown in Table 1.

[0157] Example 5

[0158] The spray drying process provided in this embodiment uses 10 kg of industrial slurry of catalytic cracking aid (solid content 40%), wherein:

[0159] The hot air inlet temperature is 450℃ and the outlet temperature is 160℃.

[0160] The hot air distribution device 5 of the spray drying tower 1 is installed 10 mm below the air inlet 2. The hot air flow rate of the uniform distribution plate 503 is 0.3 m / s, and the hot air flow rate of the distribution plate 504 is 5 m / s.

[0161] The primary spoiler 501 has a blade spacing of 400 mm and a height of 5 mm; the secondary spoiler 502 has a blade spacing of 250 mm and a height of 2 mm; the primary spoiler 501 is connected to the secondary spoiler 502, and the secondary spoiler 502 is connected to the upper surface of the uniformly distributed plate 503;

[0162] The installation position of the uniformly distributed plate 503 is about 10 mm lower than the air inlet 2, with an opening rate of 20%, an aperture of 10 mm, and an area ratio of the sparse opening area 5051 to the dense opening area 5061 of 1:3;

[0163] The distribution plate 504 is installed about 150 mm lower than the uniform distribution plate 503, with an opening ratio of 15%, an aperture of 10 mm, an area ratio of the sparse opening area 5052 to the dense opening area 5062 of 1:3, and an opening angle α of the distribution plate 504 of 45°.

[0164] The outer diameters of the connection parts of the support bases 507, 508, the uniform distribution plate 503 and the distribution plate 504 are 120 mm respectively, and the diameter reduction angle of the support base 508 of the distribution plate 504 is 45°;

[0165] The hot air outlet 301 is provided with a bell mouth, the bell mouth angle β=130°, and the ratio of the vertical distance from the lower end of the bell mouth to the lower end of the inverted cone section 102 to the vertical distance to the upper end of the inverted cone section 102 is 1:8.

[0166] The test phenomena, i.e. the product performance test results, are shown in Table 1.

[0167] Example 6

[0168] The spray drying process provided in this embodiment uses 10 kg of industrial slurry of catalytic cracking aid (solid content 40%), wherein:

[0169] The hot air inlet temperature is 620℃ and the outlet temperature is 180℃.

[0170] The hot air distribution device 5 of the spray drying tower 1 is installed 10 mm below the air inlet 2. The hot air flow rate of the uniform distribution plate 503 is 0.6 m / s, and the hot air flow rate of the distribution plate 504 is 12 m / s.

[0171] The primary spoiler 501 has a blade spacing of 250 mm and a height of 10 mm; the secondary spoiler 502 has a blade spacing of 150 mm and a height of 5 mm; the primary spoiler 501 is connected to the secondary spoiler 502, and the secondary spoiler 502 is connected to the upper surface of the uniformly distributed plate 503;

[0172] The installation position of the uniformly distributed plate 503 is about 10 mm lower than the air inlet 2, with an opening rate of 20%, an aperture of 10 mm, and an area ratio of the sparse opening area 5051 to the dense opening area 5061 of 1:5;

[0173] The distribution plate 504 is installed about 150 mm lower than the uniform distribution plate 503, with an opening rate of 10%, an aperture of 10 mm, an area ratio of the sparse opening area 5052 to the dense opening area 5062 of 1:3, and an opening angle α of the distribution plate 504 of 75°.

[0174] The outer diameters of the connection parts of the support bases 507, 508, the uniform distribution plate 503 and the distribution plate 504 are 120 mm respectively, and the diameter reduction angle of the support base 508 of the distribution plate 504 is 25°;

[0175] The hot air outlet 301 is provided with a bell mouth, the bell mouth angle β=90°, and the ratio of the vertical distance from the lower end of the bell mouth to the lower end of the inverted cone section 102 to the vertical distance to the upper end of the inverted cone section 102 is 1:3.

[0176] The test phenomena, i.e. the product performance test results, are shown in Table 1.

[0177] The product yield, particle size distribution and wear index of the comparative examples and embodiments are shown in Table 1 below

[0178] Table 1

[0179] project Product yield, m% D(V,50), μm Wear index, m% Comparative Example 1 65.2 81.22 1.8 Comparative Example 2 64.3 84.35 2.5 Comparative Example 3 66.4 85.44 2.1 Example 1 87.4 66.89 1.1 Example 2 87.9 66.21 1.0 Example 3 88.3 67.27 1.4 Example 4 88.8 68.12 1.5 Example 5 89.3 68.80 1.0 Example 6 88.9 69.12 1.0

[0180] As can be seen from Table 1:

[0181] Compared with the spray drying tower used in the comparative example, the spray drying tower using the hot air distribution device provided in the embodiment of the present invention can solve the problem of material sticking to the wall, the product particle size distribution D50 is reduced to below 70 μm, and the product yield (the yield of the sample under the tower) is increased from about 60% to more than 80%, approaching 90%.

[0182] The morphology of the composite catalytic cracking catalyst prepared in Comparative Example 1 and Example 1 is as follows: Figure 7 As shown, the left picture shows the microspheres prepared in Comparative Example 1, and the right picture shows the microspheres prepared in Example 1.

[0183] The morphology of the in-situ crystallized catalytic cracking catalysts prepared in Comparative Example 2 and Example 3 is as follows: Figure 8 As shown, the left picture shows the microspheres prepared in Comparative Example 2, and the right picture shows the microspheres prepared in Example 3.

[0184] The morphology of the in-situ crystallized catalytic cracking catalysts prepared in Comparative Example 3 and Example 5 is as follows: Figure 9 As shown, the left picture shows the microspheres prepared in Comparative Example 3, and the right picture shows the microspheres prepared in Example 5.

[0185] Depend on Figure 7 、 Figure 8 、 Figure 9 It can be seen that the microspheres prepared in Examples 1, 3, and 5 are more complete and form spherical solid particles, while the microspheres prepared in Comparative Examples 1, 2, and 3 are hollow and concave, and the particle sizes are not uniform, and some microspheres are stuck together.

Claims

1. A spray drying tower, characterized in that The spray drying tower comprises a tower body, an air inlet, an air outlet, a material outlet, a primary spoiler, a secondary spoiler, a uniform distribution plate, a distribution plate, and an atomizer; wherein, The tower body comprises a straight tube section and an inverted cone section connected to each other; The primary spoiler, secondary spoiler, uniform distribution plate and distribution plate are arranged around the sleeve of the atomizer, and their respective edges are respectively connected to the inner wall of the tower body; the blades of the primary spoiler and the blades of the secondary spoiler are arranged perpendicularly and staggered to each other; the uniform distribution plate includes a dense opening area in the central area and a sparse opening area in the peripheral area, the dense opening area of ​​the uniform distribution plate has more openings than the sparse opening area, and the dense opening area and the sparse opening area are respectively provided with openings that pass through vertically from top to bottom; the distribution plate includes a dense opening area in the central area and a sparse opening area in the peripheral area, the dense opening area of ​​the distribution plate has more openings than the sparse opening area, and the dense opening area is provided with openings that pass through vertically from top to bottom and are inclined toward the atomizer, and the sparse opening area is provided with openings that pass through vertically from top to bottom; The air outlet pipe extends from the inverted cone section of the tower body to the outside of the tower body, and the opening of the air outlet pipe located in the inverted cone section of the tower body is located at the geometric center of the inverted cone section of the tower body; the opening of the air outlet pipe located in the inverted cone section of the tower body is a bell mouth, and the direction of the bell mouth is vertically downward, and the opening angle β is 90-150 degrees; The atomizer is provided at the top of the spray drying tower, and the number of the atomizer is at least one; The discharge port is arranged at the top of the inverted cone section of the tower body; The air inlet is arranged at the top of the tower body, and its position is higher than the primary spoiler. The distribution plate is located higher than the outlet of the atomizer. The primary spoiler, secondary spoiler, uniform distribution plate and distribution plate are arranged in sequence from top to bottom.

2. The spray drying tower according to claim 1, wherein The angle α of the inclined opening is 0.5 θ≤α≤90°, wherein θ is the atomization angle of the atomizer.

3. The spray drying tower according to claim 2, wherein The angle α is 0.5 θ ≤ α ≤ 75°.

4. The spray drying tower according to claim 1, characterized in that The opening rate of the uniform distribution plate is 1-50%, the opening rate of the distribution plate is in the range of 1-30%, and the opening rate of the uniform distribution plate is greater than the opening rate of the distribution plate.

5. The spray drying tower according to claim 1, characterized in that The ratio of the area of ​​the dense opening area of ​​the uniformly distributed plate to the sparse opening area of ​​the uniformly distributed plate is 1-10:1; The area ratio of the dense opening area of ​​the distribution plate to the sparse opening area of ​​the distribution plate is 1-10:

1.

6. The spray drying tower according to claim 5, characterized in that The area ratio of the dense opening area of ​​the uniformly distributed plate to the sparse opening area of ​​the uniformly distributed plate is 1-8:

1.

7. The spray drying tower according to claim 5, characterized in that The area ratio of the dense opening area of ​​the distribution plate to the sparse opening area of ​​the distribution plate is 1-8:

1.

8. The spray drying tower according to claim 1, characterized in that The spray drying tower also includes a uniform plate support seat and a distribution plate support seat; The uniform distribution plate support is fixed on the outer wall of the sleeve of the atomizer to connect the uniform distribution plate to the sleeve of the atomizer; The distribution plate support seat is fixed on the outer wall of the sleeve of the atomizer to connect the distribution plate with the sleeve of the atomizer.

9. The spray drying tower according to claim 8, characterized in that The uniform distribution plate support seat is cylindrical or prismatic; the distribution plate support seat is in a shape of reduced diameter from top to bottom.

10. The spray drying tower according to claim 8, characterized in that The included angle between the outer wall of the distribution plate support seat and the sleeve of the atomizer is 90°-α, wherein α is the angle of the inclined openings in the dense opening area of ​​the distribution plate.

11. The spray drying tower according to claim 1, characterized in that The pitch of the blades of the primary spoiler is greater than the pitch of the blades of the secondary spoiler.

12. The spray drying tower according to claim 11, characterized in that The blade spacing of the primary spoiler is 200-600 mm, the height of the primary spoiler is 2-30 mm, the blade spacing of the secondary spoiler is 100-300 mm, and the height of the secondary spoiler is 1-15 mm.

13. The spray drying tower according to claim 1, characterized in that The ratio of the vertical distance between the lower edge of the bell mouth and the lower end of the inverted cone segment to the vertical distance between the lower edge of the bell mouth and the upper end of the inverted cone segment is 1:(1-10).

14. The spray drying tower according to claim 1, characterized in that The atomizer comprises a spray gun, a nozzle and a sleeve, wherein the spray gun is arranged in the sleeve, the nozzle is arranged at the bottom end of the spray gun, and a spray hole is arranged in the nozzle.

15. The spray drying tower according to claim 1, characterized in that The spray drying tower comprises more than two atomizers, and each atomizer is provided with a dense opening area around it.

16. A spray drying process, which is carried out using the spray drying tower according to any one of claims 1 to 15, the spray drying process comprising: Hot air enters the interior of the spray drying tower from the air inlet and passes through the primary spoiler, secondary spoiler, uniform distribution plate, and distribution plate in sequence, and then contacts the droplets formed by the atomizer, drying the droplets to obtain microspheres; The microspheres leave the spray drying tower through a discharge port; The hot air leaves the spray drying tower through the air outlet pipe.

17. The spray drying process according to claim 16, wherein The temperature of the hot air entering from the air inlet is 400℃-680℃, and the temperature of the hot air leaving from the air outlet is 80℃-200℃.

18. The spray drying process according to claim 16, wherein The microspheres are composite catalytic cracking catalysts: The temperature of the hot air entering from the air inlet is 400℃-680℃, and the temperature of the hot air leaving from the air outlet is 80℃-200℃; The flow rate of the hot air when passing through the uniform distribution plate is 0.1-0.5m / s; The flow rate of the hot air when passing through the distribution plate is 1-10m / s.

19. The spray drying process according to claim 16, wherein The microspheres are in-situ crystallized catalytic cracking catalysts: The temperature of the hot air entering from the air inlet is 400℃-600℃, and the temperature of the hot air leaving from the air outlet is 140℃-280℃; The flow rate of the hot air when passing through the uniform distribution plate is 0.1-1m / s; The flow rate of the hot air when passing through the distribution plate is 1-20m / s.

20. The spray drying process according to claim 16, wherein The microspheres are catalytic cracking aids: The temperature of the hot air entering from the air inlet is 400℃-650℃, and the temperature of the hot air leaving from the air outlet is 120℃-200℃; The flow rate of the hot air when passing through the uniform distribution plate is 0.1-0.8m / s; The flow rate of the hot air when passing through the distribution plate is 1-15m / s.

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