CN117907170A

CN117907170A - Measuring device and measuring method for sedimentation of solid phase catalyst

Info

Publication number: CN117907170A
Application number: CN202211237790.6A
Authority: CN
Inventors: 赵峻逸
Original assignee: Wanhua Chemical Group Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd
Priority date: 2022-10-11
Filing date: 2022-10-11
Publication date: 2024-04-19

Abstract

The application provides a measuring device for sedimentation of a solid phase catalyst and a measuring method using the same, wherein the measuring device comprises a premixing kettle; the sedimentation pipe is provided with an overflow port on the outer wall of the upper end of the sedimentation pipe, and a plurality of sampling ports which are axially spaced are arranged on the outer wall of the sedimentation pipe, and the sampling ports are positioned at the lower end of the overflow port; the first communication channel is arranged between the sedimentation pipe and the premixing kettle and is communicated with the lower end of the sedimentation pipe; the first pumping piece is arranged on the first communication channel, the measuring device can realize steady-state measurement, the height of the overflow port meeting the requirement of the solid content and the corresponding overflow speed under different residence time are realized, and for the solid-liquid mixture with the determined solid content, the combination of the overflow speed and the residence time which can meet the required clarity can be measured by the application, so that a reasonable operation condition range is provided for the catalyst sedimentation system of the pilot plant or the industrialized device.

Description

Measuring device and measuring method for sedimentation of solid phase catalyst

Technical Field

The invention belongs to the technical field of catalytic reaction, and particularly relates to a measuring device for sedimentation of a solid-phase catalyst and a measuring method using the same.

Background

In recent years, with the continuous development of catalytic hydrogenation processes, the use of noble metal catalysts having excellent catalytic performance and high efficiency has been increasing. In order to improve the utilization rate of the noble metal catalyst and reduce the purchase cost of the catalyst, a settling tank is generally used in an industrial device for settling and separating the solid catalyst from the reaction liquid, supernatant in the settling tank is used as a product overflow, and most of the catalyst is circulated to a reaction kettle after settling to continue the catalytic reaction. The current general index for judging the sedimentation effect of solids is the clarity of an overflow port. The required clarity of the process is met by regulating and controlling different operation conditions such as the residence time of the settling tank, the overflow speed and the like in the production.

In the prior art, the actual operating condition range is influenced by factors such as catalyst particle size distribution, solid content, circulation flow rate, honeycomb duct depth and the like, and a clarifying tank device is required to be used for measurement and determination.

However, the traditional clarifying tank device is large in size, so that the measuring materials are more and the cost is high.

Disclosure of Invention

In order to solve some or all of the above technical problems existing in the prior art, a measurement device and a measurement method for sedimentation of a solid phase catalyst are provided. The measuring device for the sedimentation of the solid phase catalyst has the advantages of small volume, simple structure and low measuring cost, and can be used for measuring and obtaining the operation parameters required by the industrialized sedimentation tank device in a laboratory.

According to an aspect of the present invention, there is provided a measurement device for sedimentation of a solid phase catalyst, comprising:

A premixing kettle,

The sedimentation tube is provided with an overflow port on the outer wall of the upper end of the sedimentation tube, and a plurality of sampling ports which are axially spaced are arranged on the outer wall of the sedimentation tube, the sampling ports are positioned at the lower end of the overflow port,

A first communication channel arranged between the sedimentation pipe and the premixing kettle, the first communication channel is communicated with the lower end of the sedimentation pipe,

A first pumping member disposed on the first communication passage.

In one embodiment, the settling tube comprises:

The overflow port and the sampling port are arranged on the straight barrel section,

A liquid storage section arranged at the lower end of the straight barrel section, the inner diameter of the liquid storage section is smaller than that of the straight barrel section,

A conical section arranged between the straight section and the liquid storage section in a communication way,

The liquid storage section is provided with a first switch valve and a second switch valve positioned at the lower end of the first switch valve, and the first communication channel is communicated with the liquid storage section at the upper end of the first switch valve.

In one embodiment, further comprising:

a slurry kettle,

A draft tube axially extending downwards from the upper end opening of the sedimentation tube and inserted into the inner cavity of the sedimentation tube,

The slurry kettle is communicated with the flow guide pipe through a second communication channel,

And a second pumping member disposed on the second communication passage.

In one embodiment, a gland is arranged at the opening of the upper end of the sedimentation pipe, an air hole communicated with the inside and the outside is arranged on the gland, and the flow guide pipe extends through the gland.

In one embodiment, a baffle ring is sleeved on the outer wall of the flow guide pipe, the axial position of the baffle ring on the flow guide pipe is variable, and the baffle ring is seated on the gland.

In one embodiment, the premix tank, the settling tube, and the slurry tank are all made of plexiglass, and the draft tube is made of stainless steel material.

In one embodiment, axially spaced multi-layer paddles are disposed within the premix tank and the slurry tank.

According to another aspect of the present invention, there is provided a measurement method using the above measurement device for solid phase catalyst sedimentation, comprising:

Step one, pumping a solid-liquid mixture into the sedimentation tube according to a set circulation flow, wherein the solid-liquid mixture is a uniformly dispersed mixture,

Step two, along with the liquid level reaching the overflow port, the set circulation flow is kept to be stable to the solid-liquid system in the sedimentation pipe,

And thirdly, sampling through the sampling port, and measuring the concentration of the sample.

In one embodiment, the method further comprises a pre-step of preparing a solid-liquid mixture in the pre-mixing kettle according to a set solid content rate, stirring the mixture until two phases are uniformly dispersed, and in the first step, the solid-liquid mixture in the pre-mixing kettle is sent into the settling tube according to a set circulating flow rate through the first communication channel.

In one embodiment, in the first step, clean water in the premixing kettle is sent into the sedimentation pipe through the first communication channel according to a set circulation flow, and the prepared solid-liquid mixture is drained into the inner cavity of the sedimentation pipe through the upper end of the sedimentation pipe.

Compared with the prior art, the invention has the advantages that: the application utilizes the sedimentation tube, so that the volume of the measuring device can be effectively reduced, and the measuring cost is further reduced. Meanwhile, the measuring device can realize steady-state measurement, realize the overflow port height and corresponding overflow speed meeting the solid content requirement under different residence time, and can measure the combination of overflow speed and residence time meeting the required clarity for the solid-liquid mixture with the determined solid content by the invention, thereby providing a reasonable operation condition range for the catalyst sedimentation system of a pilot plant or an industrial device.

Drawings

Preferred embodiments of the present invention will be described in detail below with reference to the attached drawing figures, wherein:

FIG. 1 schematically shows a measuring device for sedimentation of a solid phase catalyst according to a first embodiment of the present invention;

Fig. 2 schematically shows a measuring device for sedimentation of a solid phase catalyst according to a second embodiment of the present invention.

In the drawings, like parts are designated with like reference numerals. The figures are not drawn to scale.

Detailed Description

In order to make the technical solution and advantages of the present invention more apparent, exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. It will be apparent that the described embodiments are only some of the embodiments of the present invention and are not exhaustive of all embodiments. And embodiments of the invention and features of the embodiments may be combined with each other without conflict.

The application provides a measuring device for sedimentation of a solid phase catalyst. As shown in fig. 1, the measuring device for sedimentation of the solid phase catalyst comprises a premix tank 1, a sedimentation tube 2, a first communication channel 3 and a first pumping member 4. The premix pot 1 is a container in which a liquid or a solid-liquid mixture or the like can be stored. The sedimentation tube 2 is tubular. An overflow 21 is provided in the outer wall of the settling tube 2, which overflow 21 is easily understood to be near the upper edge of the settling tube 2. Meanwhile, a plurality of sampling ports 22 are provided on the outer wall of the settling tube 2. It will be appreciated that the sampling port 22 is located at the lower end of the overflow port 21. And, the plurality of sampling ports 22 are axially spaced apart. A first communication channel 3 is arranged between the settling tube 2 and the premix tank 1 for delivering the substances in the premix tank 1 into the inner cavity of the settling tube 2. Meanwhile, the first communication channel 3 communicates with the lower end of the settling tube 2, that is, the premix tank 1 transfers the substances to the lower end of the settling tube 2. A first pumping member 4 is provided on the first communication channel 3 for delivering a substance of a set flow rate and pressure.

In one embodiment, the settling tube 2 comprises a straight section 23, a liquid storage section 24, and a conical section 25. The straight tube section 23 is straight tube-shaped, and the overflow port 21 and the sampling port 22 are provided in the straight tube section 23. The liquid storage section 24 is provided at the lower end of the straight section 23. The inner diameter of the liquid storage section 24 is smaller than the inner diameter of the straight section 23. The cone section 25 is arranged between the straight section 23 and the liquid storage section 24 in a communicating manner and is used for playing a role in connection. A first switching valve 26 and a second switching valve 27 located at a lower end of the first switching valve 26 are provided on the reservoir section 24. The first communication channel 3 is communicated with a liquid storage section 24 at the upper end of a first switch valve 26. The reservoir 24 thus provided is mainly used for storing relatively heavy particles and is discharged through the second on-off valve 27 after the particles have been stored to a certain amount.

As shown in fig. 2, the measuring device for the sedimentation of the solid-phase catalyst further comprises a slurry kettle 5, a flow guide pipe 6, a second communication channel communication 7 and a second pumping member 8. The slurry kettle 5 is a kettle-shaped container and is mainly used for storing liquid or solid-liquid mixture. The flow guide pipe 6 is axially downwardly arranged from the upper end opening of the settling tube 2 and extends in the inner cavity of the settling tube 2 for delivering substances to the inner cavity of the settling tube 2. The second communication channel is communicated 7 to communicate the slurry kettle 5 with the flow guide pipe 6, and plays a role in communicating pipelines and channels. The second pumping member 8 is provided on the second communication passage 7 for adjusting the flow rate, the pressure, etc., and delivering a substance of a preset parameter. The working state of the actual sedimentation tank can be well simulated by arranging the flow guide pipe 6, the measured data has high reliability, and more accurate operation parameters can be provided.

A gland 9 is arranged at the upper end opening of the sedimentation tube 2, and the gland 9 can seal the upper end opening of the sedimentation tube 2 and is used for protecting substances in the sedimentation tube from falling sundries. An air hole (not shown) which is communicated with the inside and the outside is arranged on the gland 9 and is used for the flow guide pipe 6 to pass through the gland 9. A baffle ring 61 is sleeved on the outer wall of the flow guide pipe 6. The baffle 61 is variable in axial position of the draft tube 6. The retainer ring 61 sits on the gland 9. The baffle 61 may be disposed on the outer wall of the draft tube 6 by a jackscrew (not shown) passing radially through the sidewall of the baffle 61. The stop ring 61 is thus movable on the outer wall of the flow conduit 6, and the position of the stop ring 61 on the outer wall of the flow conduit 6 can also be defined by the jackscrews. Again due to the catch ring 61 sitting on the upper surface of the gland 9. The depth of the guide pipe 6 inserted into the sedimentation pipe 2 can be adjusted through the position of the baffle ring 61 on the guide pipe 6, so that actual production can be better simulated, and more accurate result data can be ensured. Of course, the present application does not have the above-described structure in order to achieve the depth of insertion of the draft tube 6 into the settling tube 2. For example, the flow guide tube 6 and the baffle ring 61 may be screw-connected. An O-ring seal is provided between the stop ring 61 and the gland 9, i.e. the stop ring 61 sits on the O-ring seal for sealing.

The premixing kettle 1, the sedimentation pipe 2 and the slurry kettle 5 are all made of organic glass. While the draft tube 6 is made of stainless steel material 316L. In particular, the straight section 23 of the sedimentation tube 2 may have an outer diameter of 0.1m and a height of 3.0m. The gland 9 is connected with the straight tube section 23 through a flange, and meanwhile, a hole with the diameter of 0.012m for the flow guide tube 6 to pass through is formed in the center of the gland 9. The overflow 21 is at a distance of 0.15m from the top end of the straight section 23, and the inner diameter of the overflow 21 is 0.03m. The sampling ports 22 may be provided in plural, for example, 9, or fewer or more, as necessary. The axial spacing of the sampling ports 22 is 0.3m, the distance from the uppermost sampling port 22 to the tip is 0.2m, and the inner diameter of the sampling port 22 is 0.01m. The inner diameter of the liquid storage section 24 is 0.05m, and the height is 0.2m. For example, the volume of the premix tank 1 may be 70L and the tank diameter 0.4m. The volume of the slurry tank 5 was 100L, and the tank diameter was 0.5m. The inner diameter of the flow guide pipe 6 is 0.01m, and the length is 3m. It should be noted that the above-mentioned arrangement is only a specific embodiment, and is not intended to limit the present application, that is, the above-mentioned specific dimensions may be set according to actual situations or working requirements.

The overflow 21 is provided with a hose 10 for transporting the overflowed material to the outside or to the inner cavity of the slurry tank 1. That is, the hose 10 can be selectively communicated with the outside or the slurry tank 1. The first pumping element 4 is a peristaltic pump, the flow range is 0.5-50L/min, the solid content range is 0-5%, and the first circulating reflux pipeline 41 is arranged to ensure the small flow accuracy. The second pumping element 8 is a peristaltic pump, the flow range is 0.1-15L/min, the solid content range is 0-10%wt, and the second circulating reflux pipeline 81 is arranged to ensure the small flow precision.

The premixing kettle 1 and the slurry kettle 5 are respectively provided with a plurality of layers of stirring paddles 11 which are axially spaced, and the stirring paddles are used for fully stirring materials and ensuring uniform mixing.

In addition, the communication lines 3,7 are provided with regulating valves 10 for control purposes.

The solid particle diameter application range of the measuring device is 0 to 250 mu m; the applicable temperature ranges from 20 ℃ to 50 ℃; the slurry solid content is applicable to the range of 0 to 10 percent by weight; the applicable range of the fluid solid content in the sedimentation tube 2 is 0 to 5 percent by weight; the flow operation range in the sedimentation tube 2 is 0.5-50L/min; the flow rate operation range in the flow guide pipe 6 is 0.1-15L/min.

The measurement method using the above-described measurement device for sedimentation of a solid phase catalyst is described in detail below with reference to fig. 1 and 2.

First, a mixed cycle method was performed by using the measuring apparatus shown in fig. 1.

Some parameters of the measuring device used are as follows. The diameter of the straight section 23 is 0.1m, the height is 3.0m, and the material is plexiglass. The distance from the overflow port 21 to the top end was 0.15m, and the inner diameter of the overflow port 21 was 0.03m. The overflow 21 is provided with a hose connection. The axial spacing of the 9 sampling ports 22 was 0.3m, the distance of the uppermost sampling port from the tip was 0.2m, and the inner diameter of the sampling port 22 was 0.01m. The inner diameter of the liquid storage section 24 is 0.05m, and the height is 0.2m. The volume of the premixing kettle 1 is 70L, the kettle diameter is 0.4m, and the premixing kettle is made of organic glass; the first pumping element 4 is a peristaltic pump, the flow range is 0.5-50L/min, the solid content range is 0-5%wt, and the first circulating reflux pipeline 41 is arranged to ensure the small flow accuracy.

Firstly, preparing a solid-liquid mixture in a premixing kettle 1 of a catalyst according to the required solid content, and stirring until two phases are uniformly dispersed; the first pumping member 4 is then opened and the solid-liquid mixture is passed through the tee at the desired circulation flow rate, the fluid and at least part of the solids from the bottom of the settling tube 2 into the settling tube 2 through the reducing section 25 into the straight section 23 and the larger solids are precipitated into the liquid storage section 24. During this time, the second switching valve 27 is closed, preventing leakage of fluid. And the first on-off valve 26 is opened to allow the relatively heavy particle size to pass. It should be noted that after the test is completed, the first switch valve 26 may be closed, and the second switch valve 27 may be opened to discharge the sediment therein. The liquid level rises in the settling tube 2 all the way to the overflow 21, maintaining the desired circulation flow until the solid-liquid system in the settling tank is stable. Finally, samples are taken through the different-height sampling ports 22, and the sample concentrations are measured respectively.

In a specific example, a solid-liquid mixture (solid particles volume median diameter 20 μm) is prepared in a premixing kettle 1 according to a solid content of 5% wt in a sedimentation pipe 2, and stirred until the two phases are uniformly dispersed; the first pumping member 4 is opened and the solid-liquid mixture is passed through the tee at the desired circulation flow rate. Fluid and part of solids enter from the bottom of the sedimentation pipe 2, enter the straight barrel section 23 through the reducing section 25, and the solids with larger particle size are precipitated to the liquid storage section 24; the liquid level rises to the overflow port 21 and returns to the premixing kettle 1 for circulation, the flow rate in the 0.01m/s sedimentation pipe 2 is kept, and the circulation flow rate of 4.71L/min is kept to the stability of the solid-liquid system in the sedimentation pipe 2; samples were taken from the different height sampling ports 22, and the sample concentration and sample particle size distribution were measured using a laser particle sizer, respectively. The clarity of the overflow height of 2.1m was 12.3mg/L. If the target clarity is below 6mg/L, the theoretical overflow height should be above 2.36 m.

Second, a solid-liquid separation method was performed using the measuring apparatus shown in fig. 2.

Some parameters of the measuring device used are as follows. The diameter of the straight cylinder section 23 is 0.1m, the height is 3.0m, and the material is organic glass; the distance from the overflow port 21 to the top end is 0.15m, the inner diameter of the overflow port is 0.03m, and the overflow port 21 is provided with a hose joint; the axial spacing of the 9 sampling ports 22 is 0.3m, the distance from the top end of the uppermost sampling port 22 to the top end is 0.2m, and the inner diameter of the sampling port 22 is 0.01m; the inner diameter of the liquid storage section 24 is 0.05m, and the height is 0.2m. The volume of the slurry kettle 5 is 100L, the kettle diameter is 0.5m, and the slurry kettle is made of organic glass; the slurry kettle feeding pump 9 is a peristaltic pump, the flow range is 0.1-15L/min, the solid content range is 0-10%wt, and the second circulating reflux pipeline 81 is arranged to ensure the small flow precision. The inner diameter of the flow guide pipe 6 is 0.01m, the length is 3m, the flow velocity in the pipe is 0.5-5 m/s, the material is 316L, and the insertion depth of the flow guide pipe 6 is adjustable.

Firstly, preparing a solid-liquid mixture in a slurry kettle 5 according to the calculated solid content, and stirring until two phases are uniformly dispersed; then, the first pumping piece 4 is opened, water is circulated from the premixing kettle 1 to the sedimentation pipe 2 according to the required flow, the liquid level rises to the overflow port 21 and overflows to the outside, and the flow speed from the required flow to the circulation number in the sedimentation pipe 2 is kept stable; then, the honeycomb duct 6 is inserted and fixed in the center of the straight section 23 according to the depth of the honeycomb duct 6; then, opening a second pumping piece 8, and pumping the solid-liquid mixture according to the required flow; maintaining the required flow rates of the first pumping member 4 and the second pumping member 8 until the solid-liquid system in the settling tube 2 is stable; finally, samples are taken from the different-height sampling ports 22, and the sample concentrations are measured, respectively.

In a practical example, a 10% wt solid-liquid mixture (solid particles having a volume median diameter of 20 μm) was prepared in a slurry tank 5 at a solid content of 5% wt in a settling tube 2, and stirred until the two phases were uniformly dispersed; opening a first pumping piece 4, and pumping circulating water according to the flow rate of 4.71L/min; the liquid level overflows to the overflow port 21 and is discharged outwards, and the required flow is kept stable until the circulating flow rate in the sedimentation pipe 2 is 0.01 m/s; the honeycomb duct 6 is inserted and fixed in the center of the straight section 23 according to the depth of the honeycomb duct 6 of 2.5 m; opening a second pumping piece 8, and pumping solid-liquid mixed solution according to a flow rate of 1.47L/min; maintaining the required flow rates of the first pumping member 4 and the second pumping member 8 until the solid-liquid system in the settling tank is stable; samples were taken from the different height sampling ports 22, and the sample concentration and sample particle size distribution were measured using a laser particle sizer, respectively. Under the conditions of the depth of the 2.5m flow guide pipe 6 and the flow rate of 4.71L/min, the clarity of the overflow height of 1.5m is 13.9mg/L. If the target clarity is below 6mg/L, the theoretical overflow height should be above 1.89 m.

The invention can pay attention to the height of the overflow port and the corresponding overflow speed which meet the requirement of the solid content under different residence time by a steady-state measurement method. For mixed solutions with a defined solids content, the combination of "overflow rate + residence time" that meets the required clarity can be measured by the present invention, providing a reasonable range of operating conditions for a catalyst settling system for pilot or commercial plants.

According to the invention, the insertion depth of the guide pipe can be adjusted to simulate an actual sedimentation tank device, and the influence of the insertion depth of the guide pipe on overflow clarity is examined, which is not possessed by the traditional sedimentation effect measuring device.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiment and all alterations and/or modifications that fall within the scope of the invention, and that are intended to be included within the scope of the invention.

Claims

1. A measurement device for sedimentation of a solid phase catalyst, comprising:

A premixing kettle,

A first pumping member disposed on the first communication passage.

2. The measurement device for sedimentation of solid phase catalyst according to claim 1, wherein the sedimentation tube comprises:

3. The measurement device for sedimentation of solid phase catalyst according to claim 2, further comprising:

a slurry kettle,

And a second pumping member disposed on the second communication passage.

4. A measuring device for sedimentation of solid phase catalyst according to claim 3, characterized in that a gland is provided at the upper end opening of the sedimentation tube, an air hole communicating inside and outside is provided on the gland, and the draft tube extends through the gland.

5. The measuring device for sedimentation of solid-phase catalyst according to claim 4, wherein a baffle ring is provided on an outer wall of the draft tube in a sleeved manner, an axial position of the baffle ring on the draft tube is changeable, and the baffle ring is seated on the gland.

6. The measurement device for solid phase catalyst sedimentation according to any one of claims 3 to 5, wherein the premix tank, sedimentation pipe and slurry tank are each made of plexiglass, and the draft tube is made of stainless steel material.

7. The measurement device for solid phase catalyst sedimentation according to any one of claims 3 to 6, wherein axially spaced multi-layer stirring paddles are provided in the pre-mixing tank and the slurry tank.

8. A measurement method using the measurement device for solid-phase catalyst sedimentation according to any one of claims 1 to 7, characterized by comprising:

9. The method according to claim 8, further comprising a preliminary step of preparing a solid-liquid mixture in the premix tank at a set solid content and stirring until two phases are uniformly dispersed, and in the first step, the solid-liquid mixture in the premix tank is fed into the settling tube at a set circulation flow rate through the first communication channel.

10. The method according to claim 8, wherein in the first step, the clean water in the pre-mixing tank is fed into the settling tube through the first communication channel at a set circulation flow rate, and the prepared solid-liquid mixture is drained into the inner cavity of the settling tube through the upper end of the settling tube.