Search

CN-122006582-A - High-pressure reaction kettle for preparing catalyst through coprecipitation

CN122006582ACN 122006582 ACN122006582 ACN 122006582ACN-122006582-A

Abstract

The invention discloses a high-pressure reaction kettle for preparing a catalyst through coprecipitation, which relates to the technical field of catalyst preparation and comprises a stirring barrel, a bin, a magnetic driving device, a rotating shaft and a stirring shaft, wherein the stirring shaft comprises a linear shaft, an upper crankshaft and a lower crankshaft on the same horizontal plane, the stirring shaft comprises the linear shaft, the upper crankshaft and the lower crankshaft which are alternately and circularly arranged on the same vertical plane, and the raw materials in the stirring barrel are subjected to cross-stage mixing among different levels through the alternate arrangement of the stirring shaft on the horizontal plane and the vertical plane. According to the invention, through the alternate arrangement of the three-form stirring shafts (the linear shaft, the upper crankshaft and the lower crankshaft) on the horizontal plane and the vertical plane and the combination of a specific parabolic motion track design, the cross-stage mixing of different layers of materials is realized, and compared with the traditional single-form stirring shaft, the flow path of the materials in the stirring barrel can be increased, and the stirring dead zone close to the kettle wall, the bottom and the top is effectively eliminated.

Inventors

  • XIAO XUEFENG
  • ZHAO SHAOHUA
  • YANG CHANGLONG
  • Mou Yuxiao

Assignees

  • 蓬莱禄昊化工机械有限公司

Dates

Publication Date
20260512
Application Date
20260204

Claims (8)

  1. 1. The high-pressure reaction kettle for preparing the catalyst through coprecipitation comprises a stirring barrel (1), wherein a bin (2) is arranged on the surface of the stirring barrel, a magnetic driving device is arranged in the bin (2), and the high-pressure reaction kettle is characterized in that: The stirring barrel also comprises a rotating shaft (3) which is coaxially arranged in the inner cavity of the stirring barrel (1), and the top end of the rotating shaft is fixedly connected with the magnetic driving device; Stirring axle, including three kinds of forms, be straight line axle (4) that the level set up respectively, upward crooked upper crankshaft (5) and downward crooked lower crankshaft (6), the stirring axle adopts the mode setting in turn in pivot (3) circumference and axial, wherein: In the same horizontal plane, the stirring shafts comprise a linear shaft (4), an upper crankshaft (5) and a lower crankshaft (6), and the circumferential interval between adjacent stirring shafts is 120 degrees; The stirring shafts comprise a linear shaft (4), an upper crankshaft (5) and a lower crankshaft (6) which are alternately and circularly arranged on the same vertical surface, and the height difference H of two adjacent layers is more than or equal to 0.1H and less than or equal to 0.3H, wherein H is the height of the stirring barrel (1); When the raw material leaves from the tail end of the upper crankshaft (5), the raw material is thrown to the edge of the inner wall of the stirring barrel (1) in a downward inclined parabola, and the starting point is lower than the vertex of the corresponding parabola; when the raw material leaves from the tail end of the lower crankshaft (6), the raw material is thrown to the edge of the inner wall of the stirring barrel (1) in a parabola which is firstly inclined upwards and then inclined downwards; When the raw material leaves from the tail end of the straight shaft (4), the raw material is thrown obliquely downwards to the edge of the inner wall of the stirring barrel (1), and the starting point is positioned at the vertex of the corresponding parabola.
  2. 2. The high-pressure reaction kettle for preparing the catalyst through coprecipitation according to claim 1, wherein the radial cross section of the stirring shaft is of a tapered structure gradually tapering from an inner end to an outer end, wherein the inner end is fixed on the peripheral side surface of a rotating shaft (3), the outer end is a free end, and the ratio of the diameter D of the inner end of the stirring shaft to the diameter D of the outer end is 1.2:1-5:1; for the straight shaft (4), the diameter of the straight shaft is uniformly reduced from the inner end to the outer end, and for the upper crankshaft (5) and the lower crankshaft (6), the reducing speed of the straight shaft from the inner end to the outer end is gradually reduced; the surface roughness of the conical structure of the stirring shaft is gradually reduced from inside to outside along the radial direction, the inner end R is less than or equal to 3.2 mu m, and the outer end R is less than or equal to 0.8 mu m, so that the fluid adhesion friction is reduced.
  3. 3. The high-pressure reaction kettle for preparing the catalyst through coprecipitation according to claim 1, wherein a fixed connection mode is adopted between the stirring shaft and the rotating shaft (3), a connecting part (7) is arranged at the inner end of the stirring shaft, an assembly groove (8) is arranged at the corresponding position of the peripheral side surface of the rotating shaft (3), and the connecting part (7) and the assembly groove (8) are fixedly connected through interference fit, welding or high-strength bolts; The connection part (7) and the assembly groove (8) are also provided with a locking structure (9) including but not limited to a locking washer, cotter pin or thread locking glue.
  4. 4. The high-pressure reaction kettle for preparing the catalyst through coprecipitation according to claim 1, wherein the upper crankshaft (5) and the lower crankshaft (6) are further installed on a rotating shaft (3) in a rotating connection mode, a bearing seat (10) is arranged on the peripheral side surface of the rotating shaft (3), and the inner ends of the upper crankshaft (5) and the lower crankshaft (6) are rotationally connected with the bearing seat (10), so that the upper crankshaft (5) and the lower crankshaft (6) can rotate by taking the bearing seat (10) as an origin; a horizontal metal torsion bar (11) is connected between one end of the upper crankshaft (5) and the lower crankshaft (6) far away from the rotating shaft (3) and the peripheral side surface of the rotating shaft (3), and two ends of the metal torsion bar (11) are respectively connected with the outer ends of the upper crankshaft (5) and the lower crankshaft (6) and the peripheral side surface of the rotating shaft (3) through universal hinges to form a space connecting rod mechanism; The metal torsion bar (11) is made of spring steel or titanium alloy and is used for limiting the upper crankshaft (5) and the lower crankshaft (6) to rotate randomly, and the swing angles of the upper crankshaft (5) and the lower crankshaft (6) are limited within the range of-30 degrees to +30 degrees.
  5. 5. The high-pressure reaction kettle for preparing the catalyst through coprecipitation according to claim 1, wherein the length distribution of the stirring shaft along the axial direction of the rotating shaft (3) is of a non-uniform design, the inner cavity of the stirring barrel (1) is divided into an upper area, a middle area and a lower area along the height direction in the axial distribution area of the rotating shaft (3), the stirring shaft positioned in the upper area and the lower area has a longer length, the stirring shaft positioned in the middle area has a shorter length, and the length proportion relation is 1.2-3.0.
  6. 6. The high-pressure reaction kettle for catalyst coprecipitation preparation according to claim 1, wherein the central angle distribution of the upper crankshaft (5) and the lower crankshaft (6) along the axial direction of the rotating shaft (3) adopts a non-uniform design, and the inner cavity of the stirring barrel (1) is divided into an upper bending area, a middle bending area and a lower bending area along the height direction in the axial distribution area of the rotating shaft (3); Wherein the upper crankshaft (5) and the lower crankshaft (6) which are positioned in the upper bending area and the lower bending area have larger central angles, the upper crankshaft (5) and the lower crankshaft (6) which are positioned in the middle bending area have smaller central angles, the ratio of the central angles is that 1.3 is less than or equal to the upper bending area or less than or equal to 3.5 or the lower bending area/the middle bending area is less than or equal to 3.5, and the central angle difference value between the upper crankshaft (5) and the lower crankshaft (6) which are positioned in the same horizontal plane is less than or equal to 15 degrees; the central angle gradient change positions of the upper crankshaft (5) and the lower crankshaft (6) adopt a continuous gradual change mode, so that abrupt flow changes are avoided.
  7. 7. The high-pressure reaction kettle for preparing the catalyst through coprecipitation according to claim 1, wherein a detachable stirring head (12) is further arranged at the tail end of the stirring shaft, the specific shape of the stirring head (12) is hemispherical or conical, and guide lines (13) are arranged on the surface of the stirring head (12); When the hemispherical stirring head (12) is adopted, the curvature radius of the hemispherical stirring head is 0.8-1.5 times of the diameter of the tail end of the stirring shaft, and when the conical stirring head (12) is adopted, the cone angle range of the hemispherical stirring head is 30-120 degrees; the stirring head (12) is fixed with the tail end of the stirring shaft in a threaded connection or snap connection mode, the stirring head (12) is made of hard alloy, engineering ceramic or surface hardening stainless steel, and the surface roughness is not more than 0.4 mu m.
  8. 8. The autoclave for the coprecipitation preparation of catalysts according to claim 1, characterized in that the number of stirring shafts distributed in space follows the principle of a multiple of 3, the number of stirring shafts distributed circumferentially is a multiple of 3 in the same horizontal plane, and the number of stirring shafts distributed axially along the rotating shaft (3) is also a multiple of 3 in the same vertical plane; For stirring shafts of different forms, the number of the upper crankshaft (5), the linear shaft (4) and the lower crankshaft (6) respectively accounts for 1/3 in the same horizontal plane, and the stirring shafts of the three forms are uniformly distributed in the same vertical plane according to the proportion of 1:1:1.

Description

High-pressure reaction kettle for preparing catalyst through coprecipitation Technical Field The invention relates to the technical field of catalyst preparation, in particular to a high-pressure reaction kettle for catalyst coprecipitation preparation. Background In the coprecipitation method preparation process of the catalyst, a plurality of metal salt solutions are uniformly mixed and synchronously precipitated under the condition of strictly controlling key parameters such as pH, temperature, feeding speed and the like, and the method is a decisive step for forming a precursor with high dispersibility, high specific surface area and excellent catalytic activity. The process is widely applied to industrial production of various heterogeneous catalysts, such as automobile tail gas purifying catalysts, fischer-Tropsch synthesis catalysts, hydrodesulfurization catalysts and the like, and the performances of the final products, including activity, selectivity, thermal stability and service life, are greatly dependent on the uniformity of microstructures in the coprecipitation process. However, conventional stirred tank structures, such as straight impellers, anchor stirred or single-form paddles, have difficulty in achieving the rapid, uniform mixing of the three-dimensional space required by the process, and they tend to form fluid dead or weak flow areas in the center, near-wall, bottom or top of the tank, resulting in excessive residence time or insufficient mixing of materials in these areas. In the coprecipitation process, the problems of overhigh local concentration, different precipitation reaction rate, asynchronous nucleation and growth process and the like are extremely easy to occur, so that uneven distribution of active components in the catalyst precursor, agglomeration of particles, excessively wide particle size distribution and obvious reduction of specific surface area are caused. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides a high-pressure reaction kettle for preparing a catalyst through coprecipitation. In order to achieve the above object, the technical scheme of the present invention is as follows: The high-pressure reaction kettle for preparing the catalyst through coprecipitation comprises a stirring barrel, wherein a bin is arranged on the surface of the stirring barrel, and a magnetic driving device is arranged in the bin; the stirring barrel is coaxially arranged in the inner cavity of the stirring barrel, and the top end of the stirring barrel is fixedly connected with the magnetic driving device; stirring axle, including three kinds of forms, be the straight line axle that the level set up respectively, the upper crankshaft of upwards bending and the lower crankshaft of downwarping, the stirring axle adopts the mode setting in rotation axis circumference and axial in turn, wherein: In the same horizontal plane, the stirring shafts comprise a linear shaft, an upper crankshaft and a lower crankshaft, and the circumferential interval between adjacent stirring shafts is 120 degrees; The stirring shafts comprise a linear shaft, an upper crankshaft and a lower crankshaft which are alternately and circularly arranged on the same vertical surface, and the height difference H of two adjacent layers is more than or equal to 0.1H and less than or equal to 0.3H, wherein H is the height of the stirring barrel; When the raw material leaves from the tail end of the upper crankshaft, the raw material is thrown to the edge of the inner wall of the stirring barrel in a downward inclined parabola, and the starting point is lower than the vertex of the corresponding parabola; When the raw material leaves from the tail end of the lower crankshaft, the raw material is thrown to the edge of the inner wall of the stirring barrel in a parabolic way of obliquely upwards and then obliquely downwards; when the raw material leaves from the tail end of the straight shaft, the raw material is thrown obliquely downwards to the edge of the inner wall of the stirring barrel, and the starting point is positioned at the vertex of the corresponding parabola. Preferably, the radial section of the stirring shaft is of a tapered structure tapering from the inner end to the outer end, wherein the inner end is fixed on the peripheral side surface of the rotating shaft, the outer end is a free end, and the ratio of the diameter D of the inner end to the diameter D of the outer end of the stirring shaft is 1.2:1-5:1; For the straight shaft, the diameter of the straight shaft is uniformly decreased from the inner end to the outer end, and for the upper crankshaft and the lower crankshaft, the decreasing speed of the diameter of the straight shaft from the inner end to the outer end is gradually decreased; the surface roughness of the conical structure of the stirring shaft is gradually reduced from inside to outside along the radial direction, the inner end R is less than o