Hydrocyclone, continuous separation device and system for separating slurry of skeletal nickel catalyst
By installing a flow guide hood and a multi-stage hydrocyclone in the hydrocyclone separator, the problem of insufficient recovery rate of fine nickel catalyst powder was solved, the separation efficiency and production safety were improved, and the production cost was reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SENNICS CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-07-10
AI Technical Summary
In the existing technology, the separation methods for skeletal nickel catalysts are inefficient, especially the recovery rate of fine powder is insufficient, which leads to increased production costs and safety hazards. Intermittent filtration methods are prone to clogging, and magnetic separation methods are inefficient, failing to effectively solve the specific problems.
A multi-stage hydrocyclone separator is used to replace existing separation equipment, including stainless steel powder sintered filter cartridges as filter media and magnetic adsorption separators.
A highly efficient solid-liquid separator was achieved. By installing a flow guide inside the cylindrical body, unseparated fine nickel catalyst powder was prevented from entering the overflow pipe, thereby improving separation efficiency and recovery rate and reducing production costs.
Smart Images
Figure CN224474743U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of continuous separation devices, and in particular to a hydrocyclone separator, continuous separation device and system for separating slurry of nickel skeletal catalysts. Background Technology
[0002] RT paste, scientifically known as 4-aminodiphenylamine, is a key intermediate in the p-phenylenediamine-based rubber antioxidants 4010NA (N-isopropyl-N'-phenyl-p-phenylenediamine) and 6PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine). The nitrobenzene process for producing RT paste is currently recognized worldwide as a green, environmentally friendly, and low-carbon process. Using aniline and nitrobenzene as raw materials, under the action of an organic base catalyst, a condensation and dehydration reaction produces a condensation liquid of 4-nitrosodiphenylamine and 4-nitrodiphenylamine. These two do not need to be separated; hydrogen is directly introduced and hydrogenated using a skeletal nickel catalyst to produce a reduced solution of 4-aminodiphenylamine. During the RT paste production process, the skeletal nickel catalyst undergoes wear and breakage, generating some extremely fine catalyst powder. If this powder is not promptly recovered and recycled, it not only affects the hydrogenation reaction time but also increases the catalyst's operating costs.
[0003] Skeleton nickel, also known as Raney nickel, is a catalyst for catalytic hydrogenation reactions. Catalytic hydrogenation is one of the unit reactions widely used in fine chemicals, biochemicals, and pharmaceutical raw material production. Typically, after the hydrogenation catalytic reaction, the Raney nickel catalyst needs to be filtered and separated from the reaction solution for reuse. Existing techniques for separating skeleton nickel catalysts include, but are not limited to, filtration, gravity sedimentation, centrifugation, and magnetic separation. Among these, filtration is a commonly used intermittent separation method in factories both domestically and internationally. Sintered stainless steel powder filter elements are generally used as the filter medium. However, after a few batches of operation, the filter elements become completely clogged and ineffective, sometimes even unable to be backwashed for regeneration. Insufficient filtration capacity due to the fine catalyst powder has long been a bottleneck problem hindering the improvement of industrial plant capacity. Intermittent filtration exposes Raney nickel to air to dry, which can naturally cause a fire hazard. Iron-based and cobalt-based catalysts are magnetic fine particles. For the separation of liquid products from catalysts, some manufacturers employ magnetic adsorption separation technology. This involves directly collecting the unsettled catalyst particles containing magnetic solids in a settling tank equipped with a magnetic separation device. Once the accumulated catalyst reaches a certain weight, the magnetic field is removed, causing the catalyst to agglomerate and quickly settle to the bottom of the tank, thus achieving liquid-solid separation. However, during production, it has been found that prolonged mechanical stirring of the catalyst causes varying degrees of breakage in the powdered nickel catalyst, rendering it essentially non-magnetic and impossible to collect and recover, resulting in losses and increased production costs. Utility Model Content
[0004] To address the problems existing in the prior art, this utility model provides a hydrocyclone separator, a continuous separation device, and a system for separating slurry of nickel framework catalysts. The hydrocyclone separator of this utility model can significantly reduce the turbulence and disturbance of the fluid at the inlet caused by directly feeding the tangential feed pipe into the hydrocyclone, resulting in high separation efficiency and making it highly suitable for industrial production.
[0005] Specifically, the first aspect of this utility model provides a hydrocyclone separator for separating slurry of skeletal nickel catalysts, the hydrocyclone separator comprising:
[0006] The cylindrical body comprises an upper cylindrical body and a lower conical cylindrical body;
[0007] The feed inlet is located tangentially to the cylindrical body.
[0008] An overflow pipe is provided at the upper end of the cylindrical body;
[0009] A flow guide is disposed inside the cylindrical body and located outside the overflow pipe. The flow guide is a cylinder that is concentric with the cylindrical body and coaxial with the overflow pipe.
[0010] The bottom outlet is located at the lower end of the conical cylinder.
[0011] In one or more embodiments, the height of the cylindrical body is 0.7 to 2.0 times the diameter of the cylindrical body.
[0012] In one or more embodiments, the diameter of the feed inlet is 0.13-0.29 times the diameter of the cylindrical body.
[0013] In one or more embodiments, the diameter of the overflow port of the overflow pipe is 1-2 times the diameter of the feed port.
[0014] In one or more embodiments, the diameter of the flow deflector is 0.7-0.9 times the diameter of the cylindrical body.
[0015] In one or more embodiments, the height of the air deflector is 0.7-1.0 times the height of the cylindrical body.
[0016] In one or more embodiments, the diameter of the underflow outlet is 0.15-0.25 times the diameter of the cylindrical body.
[0017] In one or more embodiments, the cone angle of the conical cylinder is 6-20°, preferably 6-15°.
[0018] The second aspect of this utility model provides a continuous separation device for separating slurry of nickel skeletal catalysts, which includes two or more hydrocyclones for separating slurry of nickel skeletal catalysts as described in any embodiment herein.
[0019] A third aspect of this invention provides a system for separating a skeletal nickel catalyst slurry, comprising a settling tank separation device and at least one hydrocyclone separator as described in any embodiment herein, connected in sequence; the settling tank separation device is used to perform sedimentation separation of most of the coarse particles of catalyst in the skeletal nickel catalyst slurry; the hydrocyclone separator is used to separate the fine powder skeletal nickel catalyst slurry that the settling tank separation device cannot separate. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the hydrocyclone separator for separating the nickel catalyst slurry in Example 1.
[0021] Figure 2 This is a cross-sectional schematic diagram of the hydrocyclone separator in Example 1.
[0022] Explanation of reference numerals in the attached diagram: 1 is the feed inlet, 2 is the cylindrical body, 3 is the flow guide, 4 is the conical body, 5 is the underflow outlet, 6 is the overflow pipe, d1 is the diameter of the feed inlet, d2 is the diameter of the overflow outlet, d3 is the diameter of the flow guide, d4 is the diameter of the underflow outlet, and D is the diameter of the cylindrical body. Detailed Implementation
[0023] To enable those skilled in the art to understand the features and effects of this utility model, the terms and expressions mentioned herein are explained and defined in general terms below. Unless otherwise specified, all technical and scientific terms used herein have the common meaning understood by those skilled in the art regarding this utility model, and in case of conflict, the definitions herein shall prevail.
[0024] The theories or mechanisms described and disclosed herein, whether right or wrong, should not limit the scope of this invention in any way; that is, the content of this invention can be implemented without being limited by any specific theory or mechanism.
[0025] In this document, the terms “contains,” “includes,” “containing,” and similar terms encompass the meanings of “basically composed of” and “composed of.” For example, when this document discloses “A contains B and C,” “A is basically composed of B and C” and “A is composed of B and C” should be considered as having been disclosed in this document.
[0026] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values (including integers and fractions) within those ranges.
[0027] Unless otherwise specified, percentages refer to mass percentages and proportions refer to mass ratios in this article.
[0028] In this document, when describing embodiments or examples, it should be understood that it is not intended to limit the present invention to those embodiments or examples. Rather, all alternatives, modifications, and equivalents of the methods and materials described herein are covered within the scope defined by the claims.
[0029] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.
[0030] To address the aforementioned shortcomings of existing technologies, the inventors propose using online single-stage or multi-stage hydrocyclones to replace existing separation equipment, including but not limited to stainless steel metal powder sintered filter cartridges as filter media and magnetic adsorption separators.
[0031] In this article, the framework nickel catalyst slurry refers to the condensation liquid of aniline and nitrobenzene as raw materials, which are produced by condensation and dehydration reaction to generate 4-nitrosodiphenylamine and 4-nitrodiphenylamine. The two do not need to be separated and can be directly reduced by hydrogenation using a framework nickel catalyst to generate 4-aminodiphenylamine.
[0032] This utility model discloses a hydrocyclone separator for separating slurry of nickel skeleton catalyst. By providing a flow guide shroud inside the cylindrical body and placing the flow guide shroud around the overflow pipe, it acts as a baffle, effectively preventing unseparated fine powder of nickel skeleton catalyst from moving downwards along the outer wall of the overflow pipe due to turbulence, and preventing it from entering the overflow pipe and overflowing, thereby greatly improving the separation efficiency of the hydrocyclone separator.
[0033] A hydrocyclone, also known as a cyclone separator, is a device that uses the principle of centrifugal sedimentation to separate solid particles from a suspension. Typically, the structure and working principle of a hydrocyclone are as follows: a hydrocyclone is a device for separating heterogeneous liquid mixtures, using the density difference between phases under the action of centrifugal force to separate two or more phases. Because the strength of the centrifugal force field is much greater than the strength of the gravitational field, hydrocyclones are more efficient than gravity separation devices.
[0034] The hydrocyclone separator for separating skeletal nickel catalyst slurry of this invention includes: a cylinder, a feed inlet, an overflow pipe, a flow guide, and an underflow outlet.
[0035] The upper part of the cylinder of this invention is cylindrical, and the lower part is conical. In some embodiments, the straight edge height H of the cylindrical cylinder is (0.7-2.0)D, where D is the diameter of the cylindrical cylinder (also called the hydrocyclone diameter). The height of the cylindrical cylinder of the hydrocyclone used for solid-liquid separation should be appropriately taken to the maximum value. As the height of the cylindrical cylinder increases, the inner cavity of the hydrocyclone becomes larger, and the residence time of the fluid inside it becomes longer, which will improve the separation efficiency and production capacity of the hydrocyclone and reduce energy consumption. In some specific embodiments, the cone angle of the conical cylinder is 20-45°, preferably 25-35°, such as 30°. Under the same feed pressure, the larger the cone angle, the greater the resistance, the smaller the production capacity, the lower the separation efficiency, and the coarser the separated particle size; decreasing the cone angle results in a finer separated particle size. Too fine a separated particle size can also cause wear and outlet blockage.
[0036] The feed inlet is located tangentially to one side of the cylindrical body. When the hydrocyclone is operating, the mixture of raw materials to be separated enters the hydrocyclone tangentially through the feed inlet under pressure. In some embodiments, the feed inlet diameter d1 is (0.13-0.29)D. Increasing the feed inlet diameter will improve the hydrocyclone's production capacity and increase the separated particle size, and may also reduce wear.
[0037] An overflow pipe is located at the upper end of the cylindrical body and connected to the center of the top cover. In some embodiments, the overflow pipe is welded to the top cover of the cylindrical body. In some embodiments, the diameter d2 of the upper outlet of the overflow pipe, i.e., the overflow port, is (1-2)d1. Generally, the diameter of the overflow port should be slightly larger than the diameter of the feed inlet. The larger the diameter of the overflow port, the larger the separated particle size and the greater the production capacity, but the classification efficiency will decrease. When the inlet pressure remains constant, increasing the overflow port diameter within a certain range will lead to an increase in production capacity and an increase in the separated particle size.
[0038] A flow guide is disposed inside the cylindrical body and outside the overflow pipe. The flow guide is a cylinder concentric with the cylindrical body and coaxial with the overflow pipe. Adding the flow guide reduces the fluid flow area, thus increasing the fluid velocity and linear velocity, which is beneficial for solid-liquid separation. In some embodiments, the diameter d3 of the flow guide is (0.7-0.9) times the diameter D of the cylindrical body, such as 0.85 times. In some embodiments, the height of the flow guide is (0.7-1.0) times the height of the cylindrical body, such as 0.75 times. The size of the gap between the flow guide and the cylindrical body determines the tangential feed inlet linear velocity and the magnitude of the rotational centrifugal force, thereby increasing the separation intensity and efficiency of the solid powder framework nickel catalyst.
[0039] An underflow outlet is located at the lower end of the conical cylinder. The diameter of the underflow outlet can be smaller than the diameter of the overflow outlet. In some embodiments, the underflow outlet diameter d4 is (0.15-0.25)D.
[0040] This utility model exemplifies a hydrocyclone separator for separating skeletal nickel catalyst slurries, such as... Figure 1 As shown, it includes: a cylindrical body 2, a conical body 4, a feed inlet 1, a flow guide 3, an overflow pipe 6, and a bottom outlet 5. The overflow pipe 6 is located at the upper end of the cylindrical body 2 and is connected to the center of the top cover. The feed inlet 1 enters the hydrocyclone separator tangentially along the side of the upper end of the cylindrical body 2. The bottom outlet 5 is located at the lower end of the conical body. The flow guide 3 is located inside the cylindrical body 2 and is positioned around the overflow pipe 6. The flow guide 3 and the cylindrical body 2 are concentric cylinders and are coaxial with the overflow pipe 6. Figure 2 As shown. Both the overflow pipe 6 and the flow guide shroud 3 are welded to the top cover of the cylindrical body 2.
[0041] This invention also provides a continuous separation device for separating skeletal nickel catalyst slurry, comprising a multi-stage hydrocyclone separator as described herein. By setting up multi-stage hydrocyclones, the settling, separation, recovery, and reuse efficiency of fine catalyst powder can be improved. In some embodiments, the continuous separation device includes two stages of hydrocyclones as described herein for separating skeletal nickel catalyst slurry. Fine catalyst powder overflowing from the first-stage hydrocyclone, which has not had time to completely settle, is further introduced into the second-stage hydrocyclone for further separation, thereby improving the settling effect of fine catalyst powder. This achieves a high recovery rate of skeletal nickel catalyst and reduces production and operating costs.
[0042] This invention also provides a separation system for a framework nickel catalyst slurry, comprising a settling tank separation device and at least one hydrocyclone separator as described herein, connected in sequence. The settling tank separation device is used to separate most of the coarse catalyst particles in the framework nickel catalyst slurry through settling. The hydrocyclone separator is used to further separate the fine powder framework nickel catalyst slurry that cannot be separated by the settling tank separation device. The framework nickel catalyst slurry (also known as hydrogenation reduction liquid slurry) is depressurized and passes through a settling tank (preliminary separation). The liquid-solid mixture is then continuously fed tangentially into a hydrocyclone for classification under the action of a high-pressure feed pump. The underflow, rich in coarse particles, is returned to the first hydrogenation reactor, while the overflow, mainly composed of fine powder, is collected and further processed. To improve the settling effect of the fine catalyst powder, the overflow slurry can be further introduced into a second-stage hydrocyclone to further recover the fine catalyst powder that did not have time to settle from the overflow of the first-stage hydrocyclone.
[0043] The method for separating framework nickel catalyst slurry using a hydrocyclone separator as described in any embodiment of this document includes the following steps:
[0044] The skeletal nickel catalyst slurry enters the hydrocyclone tangentially through the feed inlet for separation. Fine catalyst powder is discharged to the outside through the overflow outlet of the overflow pipe, while coarse catalyst particles are discharged to the outside through the underflow outlet. In some embodiments, the coarse catalyst particles have a mesh size of 40-100 mesh, and the fine catalyst powder particles have a mesh size of 200-300 mesh.
[0045] The nickel slurry feedstock is introduced into the hydrocyclone tangentially through the inlet at a certain pressure. Simultaneously, the continuously flowing feed fluid propels the fluid within the guide tube, causing it to rotate and move downwards in a spiral motion. Upon entering the conical section, the rotating liquid's rotation speed increases due to the narrowing inner diameter of the hydrocyclone. However, the underflow port of the hydrocyclone has a small diameter, preventing all the feedstock from being discharged. An overflow pipe at the top of the cylinder allows a portion of the component with lower density (or diameter) to flow towards the hydrocyclone's axis under greater centrifugal force, while simultaneously moving spirally upwards towards the overflow pipe, forming an internal vortex, and ultimately discharging out through the overflow port. Meanwhile, the component with higher density (or diameter) is also subjected to centrifugal force. When this force exceeds the flow resistance, it overcomes the flow resistance and moves towards the hydrocyclone's sidewall, eventually being discharged out through the underflow port under the impetus of the subsequent fluid, thus achieving separation.
[0046] The beneficial effects of this utility model are:
[0047] 1. Adding a flow guide shroud inside the cylinder of the hydrocyclone can greatly reduce the disturbance and turbulence of the fluid at the feed inlet caused by direct feeding into the hydrocyclone through a tangential feed pipe. Due to the large local energy loss caused by fluid turning loss and eddy current loss.
[0048] 2. Increasing the length of the cylindrical section of the hydrocyclone enlarges the inner cavity of the hydrocyclone, allowing the fluid to reside inside for a longer period. This will improve the separation efficiency and production capacity of the hydrocyclone while reducing energy consumption.
[0049] 3. Increasing the feed inlet diameter will improve the hydrocyclone's production capacity and increase the separation particle size, and may also reduce wear;
[0050] 4. A larger overflow port diameter results in larger separated particle sizes and increased production capacity, but also a decrease in classification efficiency. The overflow port diameter should be slightly larger than the feed port diameter.
[0051] The present invention will be described below by way of specific embodiments. It should be understood that these embodiments are merely illustrative and are not intended to limit the scope of the present invention. Unless otherwise stated, the methods, reagents, and materials used in the embodiments are conventional methods, reagents, and materials in the art. The raw material compounds in the embodiments are all commercially available.
[0052] Example 1
[0053] This embodiment provides a hydrocyclone separator for separating slurry of skeletal nickel catalysts, such as... Figure 1 As shown, it includes a feed inlet 1, a cylindrical body 2, a flow guide 3, a conical body 4, an underflow outlet 5, and an overflow pipe 6.
[0054] The height H of the cylindrical body 2 is 2.0D, where D is the diameter of the hydrocyclone (i.e., the diameter of the cylindrical body 2). D = 150mm, H = 300mm.
[0055] The feed inlet 1 enters the hydrocyclone separator tangentially along the side of the upper end of the cylindrical body 2. The diameter d1 of the feed inlet 1 is 0.27D. d1 = 0.27 * 150 = 40 mm.
[0056] Overflow pipe 6 is located at the upper end of cylindrical body 2 and connected to the center of the top cover. The diameter d2 of the upper outlet of overflow pipe 6, i.e., the overflow port, is 1.5d1. d2 = 1.5 * 40 = 60 mm.
[0057] The underflow outlet 5 is located at the lower end of the conical cylinder 4. The diameter d3 of the underflow outlet 5 is 0.2D. d3 = 0.2 * 150 = 30 mm.
[0058] The flow guide shroud 3 is located inside the cylindrical body 2 and around the overflow pipe 6. For example... Figure 2 As shown, the flow deflector 3 is a cylinder concentric with the cylindrical body 2 and coaxial with the overflow pipe 6. Both the overflow pipe 6 and the flow deflector 3 are welded to the top cover of the cylindrical body 2. The diameter d4 of the flow deflector 3 is 0.85 times the diameter D of the cylindrical body 2. The height of the flow deflector 3 is 0.75 times the height of the cylindrical body 2.
[0059] The cone angle of the conical cylinder 4 is 30°.
[0060] This embodiment also provides a method for separating framework nickel catalyst slurry using the above-described hydrocyclone separator, comprising the following steps:
[0061] The skeletal nickel catalyst slurry enters the hydrocyclone separator tangentially through the feed inlet 1 to generate centrifugal force, which facilitates solid-liquid separation. The fine catalyst powder is discharged to the outside through the overflow pipe 6, while the coarse catalyst particles are discharged to the outside through the underflow port 5. The coarse catalyst particles have a mesh size of 40-100 mesh, and the fine catalyst powder particles have a mesh size of 200-300 mesh.
[0062] In Example 1, the solid content of the catalyst powder flowing out of the overflow pipe 6 does not exceed 0.01%.
[0063] Comparative Example 1
[0064] The only difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not have a fairing.
[0065] In Comparative Example 1, the solid content of the catalyst fine powder flowing out of the overflow pipe 6 was 0.3%.
Claims
1. A hydrocyclone separator for separating slurry of framework nickel catalyst, characterized in that, The hydrocyclone separator includes: The cylindrical body comprises an upper cylindrical body and a lower conical cylindrical body; The feed inlet is located tangentially to the cylindrical body. An overflow pipe is provided at the upper end of the cylindrical body; A flow guide is disposed inside the cylindrical body and located outside the overflow pipe. The flow guide is a cylinder that is concentric with the cylindrical body and coaxial with the overflow pipe. The bottom outlet is located at the lower end of the conical cylinder.
2. The hydrocyclone separator as described in claim 1, characterized in that, The height of the cylindrical body is 0.7-2.0 times the diameter of the cylindrical body.
3. The hydrocyclone separator as described in claim 1, characterized in that, The diameter of the feed inlet is 0.13-0.29 times the diameter of the cylindrical body.
4. The hydrocyclone separator as described in claim 1, characterized in that, The diameter of the overflow port of the overflow pipe is 1-2 times the diameter of the feed port.
5. The hydrocyclone separator as described in claim 1, characterized in that, The diameter of the flow guide is 0.7-0.9 times the diameter of the cylindrical body.
6. The hydrocyclone separator as described in claim 1, characterized in that, The height of the flow guide is 0.7-1.0 times the height of the cylindrical body.
7. The hydrocyclone separator as described in claim 1, characterized in that, The diameter of the underflow outlet is 0.15-0.25 times the diameter of the cylindrical body.
8. The hydrocyclone separator as described in claim 1, characterized in that, The cone angle of the conical cylinder is 20-45°.
9. A continuous separation apparatus for separating slurry of nickel-based framework catalysts, characterized in that, It includes a hydrocyclone separator with two or more stages for separating skeletal nickel catalyst slurries as described in any one of claims 1-8.
10. A system for separating a slurry of framework nickel catalysts, characterized in that, It includes a settling tank separation device and at least one hydrocyclone separator as described in any one of claims 1-8, connected in sequence; the settling tank separation device is used to perform the majority of the settling separation of coarse particles of the nickel slurry; the hydrocyclone separator is used to separate the fine powder nickel slurry that the settling tank separation device cannot separate.