Liquid sealing structure for centrifugal extractor core shaft and centrifugal extractor

Abstract

The present invention relates to a liquid sealing structure for a centrifugal extractor mandrel and a centrifugal extractor. The liquid sealing structure is arranged between the upper cover plate of the shell of the centrifugal extractor and the bearing seat. The centrifugal extractor also includes a mandrel, and the mandrel vertically passes through the bearing seat and the upper cover plate of the shell and extends into the interior of the centrifugal extractor. The liquid sealing structure includes a groove arranged on the upper end surface of the upper cover plate of the shell, the groove is arranged circumferentially along the upper end surface of the upper cover plate of the shell, and the upper end of the groove is connected to the bearing seat. A liquid sealing chamber is arranged in the groove, and a liquid sealing medium is arranged in the liquid sealing chamber. A liquid inlet connected to the liquid sealing chamber for the liquid sealing medium to enter is opened at the lower part of the bearing seat. In this way, no gas leakage can be achieved, which not only meets the sealing requirements, avoids the volatile substances in the feed liquid in the machine from volatilizing to the outside of the centrifugal extractor to cause material waste and environmental pollution, but also overcomes various shortcomings in the above-mentioned traditional sealing technology.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid sealing, and more specifically to a liquid sealing structure for a core shaft of a centrifugal extractor and a centrifugal extractor. Background Art

[0002] Centrifugal extractor is a highly efficient liquid-liquid extraction and separation equipment. It uses the centrifugal force generated by the high-speed rotation of the drum to mix and transfer two liquid phases with density difference and separate them. It is now widely used in chemical, petroleum, nuclear energy, medicine, biology, food, hydrometallurgy, environmental protection and other fields. In the extraction and separation process of centrifugal extractor, the extractant and the liquid to be extracted usually contain volatile substances. In order to prevent the volatile substances in the liquid in the machine from volatilizing to the outside of the centrifugal extractor to cause material waste and environmental pollution, it is usually necessary to introduce a slightly positive pressure inert gas into the upper space of the collection chamber for protection. Therefore, the upper shaft seal of the centrifugal extractor needs to be able to achieve a gas sealing design.

[0003] The casing of the current centrifugal extractor is connected to the upper cover plate of the shell through a flange, a bearing seat is sleeved on the core shaft, and the core shaft vertically passes through the bearing seat and the upper cover plate of the shell and extends into the interior of the centrifugal extractor, the bearing seat is fixed above the upper cover plate of the shell, and a bearing is sleeved on the core shaft in the bearing seat, and there is a gap between the core shaft and the upper cover plate of the shell. Therefore, the centrifugal extractor should be provided with a sealing structure for the gap.

[0004] Existing shaft sealing technologies include magnetic fluid seals, mechanical seals, and packing seals. Magnetic fluid seals, that is, magnetic fluid forms a liquid barrier between the sealing areas, which is usually called a liquid O-ring. The device is composed of a non-magnetic seat, a bearing, a magnetic pole, a permanent magnet, a magnetic shaft, and a magnetic fluid. Under the action of a uniform and stable magnetic field, the magnetic fluid is filled in the set space to establish a multi-level "O-ring" to achieve a sealing effect. Magnetic fluid seals have good airtightness, but they also have high mechanical precision, high material conductivity, and high cost. These disadvantages have caused certain limitations in the application of magnetic fluid seals. Mechanical seals have the disadvantages of large wear, high requirements for the feed liquid (the feed liquid cannot contain particles), easy heat generation and water cooling, so few centrifugal extraction equipment use this sealing technology; packing seals are not suitable for highly corrosive liquids. The effects of contact seals (skeleton oil seals) and non-contact seals (labyrinth seals) are not ideal.

[0005] Since the sealing space of the upper cover of the outer cylinder of the centrifugal extractor is small, the commonly used air-tight sealing structure cannot achieve an ideal sealing effect; however, increasing the sealing space may cause unnecessary cost waste and bring about adverse effects such as excessive cantilever length.

[0006] Therefore, how to overcome the deficiencies in the above-mentioned traditional sealing technology has become an important technical problem to be solved by professionals in this field. Summary of the invention

[0007] The present invention provides a liquid sealing structure for a centrifugal extractor core shaft and a centrifugal extractor. The liquid sealing structure is used to seal the core shaft, which can achieve no gas leakage. It can not only meet the sealing requirements and avoid the volatile substances in the feed liquid in the machine from volatilizing to the outside of the centrifugal extractor to cause material waste and environmental pollution, but also overcome various shortcomings of the above-mentioned traditional sealing technology.

[0008] The liquid sealing structure for the core shaft of the centrifugal extractor of the present invention adopts the following technical scheme:

[0009] A liquid sealing structure for a centrifugal extractor core shaft, the liquid sealing structure is arranged between the upper cover plate of the centrifugal extractor shell and the bearing seat, the centrifugal extractor also includes a core shaft, and the core shaft vertically passes through the bearing seat and the upper cover plate of the shell and extends into the interior of the centrifugal extractor, characterized in that the liquid sealing structure includes a groove arranged on the upper end surface of the upper cover plate of the shell, the groove is arranged circumferentially along the upper end surface of the upper cover plate of the shell, and the upper end of the groove is connected to the bearing seat, a liquid sealing chamber is arranged in the groove, a liquid sealing medium is arranged in the liquid sealing chamber, and a liquid inlet connected to the liquid sealing chamber and for the liquid sealing medium to enter is opened at the lower part of the bearing seat.

[0010] Preferably, the liquid sealing chamber includes a dynamic sealing chamber and a static sealing chamber located below the dynamic sealing chamber and connected to the dynamic sealing chamber. The liquid sealing medium is located in the static sealing chamber when the centrifugal extractor is in a stationary state. The cross-sectional shape of the static sealing chamber is a "U"-shaped structure. A baffle is welded along the circumference of the core shaft in the dynamic sealing chamber. The baffle includes a horizontal baffle and a vertical baffle. The cross-sectional shape forms a "T"-shaped structure. The vertical baffle extends into the groove of the "U"-shaped structure. A web is provided at the edge of the horizontal baffle. The web includes a first web located on the upper end surface of the horizontal baffle and a second web located on the lower end surface of the horizontal baffle. The length of the first web is greater than the length of the second web, and the number of the first web is equal to the number of the second web. When the centrifugal extractor is in operation, the liquid sealing medium is located in the dynamic sealing chamber to prevent gas leakage inside the shell.

[0011] Preferably, the liquid inlet is communicated with the liquid sealing chamber via a liquid inlet passage opened inside the bearing seat, and a control valve is provided at the liquid inlet.

[0012] Preferably, an annular groove is provided at the mating installation position between the bearing seat and the upper cover plate of the housing, and an O-ring is installed.

[0013] Preferably, the bearing seat is fixedly connected to the housing upper cover plate bolt.

[0014] Preferably, an upper pressure cover is provided at the upper end of the bearing seat, and the upper pressure cover is fixedly connected to the bearing seat.

[0015] Preferably, a cushion block is provided between the upper pressure cover and the core shaft, and a first skeleton oil seal structure capable of preventing dust and air is provided on the side wall of the upper pressure cover.

[0016] Preferably, a bearing is sleeved on the core shaft in the bearing seat, and a second skeleton oil seal structure capable of preventing gas from entering is provided on the inner wall of the bearing seat below the bearing.

[0017] Preferably, the vertical baffle is configured as a circular ring structure.

[0018] The present invention also provides a centrifugal extractor, comprising the liquid sealing structure as described in any one of the above items.

[0019] The beneficial effects of the present invention are: a liquid sealing structure for a centrifugal extractor mandrel and a centrifugal extractor, the liquid sealing structure comprising a groove arranged on the upper end surface of the upper cover plate of the shell, the groove being arranged along the circumference of the upper end surface of the upper cover plate of the shell, and the upper end of the groove being connected to the bearing seat, a liquid sealing chamber being arranged in the groove, a liquid sealing medium being arranged in the liquid sealing chamber, a liquid inlet being connected to the liquid sealing chamber and for the liquid sealing medium to enter is arranged below the bearing seat, the shaft seal is completed by filling the liquid sealing medium into the liquid sealing chamber, the sealing medium can be selected from the internal feed liquid of the centrifuge to avoid contamination of the internal feed liquid of the centrifuge, and the position radius of the feed liquid injection nozzle of the liquid inlet must be smaller than the radius of the first web, otherwise the liquid cannot be introduced due to pressure problems. In this way, the sealing problem between the mandrel and the shell of the centrifugal extractor is solved, the service life is long, the structure is reasonable, the safety and reliability are high, not only can the sealing requirements be met, but also the volatile substances in the feed liquid in the machine are avoided from volatilizing to the outside of the centrifugal extractor to cause material waste and environmental pollution, and various deficiencies in the above-mentioned traditional sealing technology are overcome.

[0020] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0023] Figure 1 It is a structural schematic diagram of a liquid sealing solution for a core shaft of a centrifugal extractor in an embodiment of the present invention;

[0024] Figure 2 It is a partial enlarged view of the liquid sealing structure in the embodiment of the present invention;

[0025] Figure 3 for Figure 1 Enlarged view of point A in the middle.

[0026] In the figure:

[0027] 1-housing upper cover, 2-bearing seat, 3-core shaft, 4-bearing, 5-liquid sealing chamber, 6-liquid sealing medium, 7-liquid inlet, 8-dynamic sealing chamber, 9-static sealing chamber, 10-horizontal baffle, 11-vertical baffle, 12-first web, 13-second web, 14-liquid inlet channel, 15-O-ring, 16-hexagon socket bolt, 17-upper pressure cover, 18-cylindrical head hexagon socket screw, 19-gasket, 20-first skeleton oil seal structure, 21-second skeleton oil seal structure, 22-housing.

[0028] Specific implementation room

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The following is an explanation of the embodiments with reference to the accompanying drawings. In addition, the embodiments shown below do not limit the invention described in the claims. In addition, the entire contents of the configurations shown in the following embodiments are not limited to the solutions required as the invention described in the claims.

[0031] refer to Figure 1-3 As shown, this specific embodiment provides a liquid sealing structure for a centrifugal extractor core shaft, such as Figure 1As shown, the liquid sealing structure is arranged between the upper cover plate 1 and the bearing seat 2 of the centrifugal extractor. The centrifugal extractor also includes a core shaft 3, and the core shaft 3 vertically passes through the bearing seat 2 and the upper cover plate 1 of the shell and extends into the interior of the centrifugal extractor. Specifically, the upper cover plate 1 of the shell is set as a flange cover plate, and the bearing seat 2 is fixed to the upper end of the upper cover plate 1 of the shell. Preferably, the bearing seat 2 and the upper cover plate 1 of the shell are fixedly connected by hexagon socket bolts 16, and are firmly fixed. A bearing 4 is sleeved on the core shaft 3 in the bearing seat 2. The liquid sealing structure includes a groove arranged on the upper end surface of the upper cover plate 1 of the shell, and the groove is along the upper cover plate of the shell. 1 is circumferentially arranged on the upper end surface, and the upper end of the groove is connected to the bearing seat 2, a liquid sealing chamber 5 is arranged in the groove, a liquid sealing medium 6 is arranged in the liquid sealing chamber 5, and a liquid inlet 7 connected with the liquid sealing chamber 5 and for the liquid sealing medium 6 to enter is opened below the bearing seat 2, and the liquid sealing medium 6 enters the liquid sealing chamber 5 through the liquid inlet 7, which can achieve no gas leakage, solve the sealing problem of the centrifugal extractor core shaft 3 and the shell 22, and has a long service life, a reasonable structure, and high safety and reliability. Specifically, the sealing medium can be selected from the internal feed liquid of the centrifuge to avoid contamination of the internal feed liquid of the centrifuge.

[0032] In this way, the core shaft 3 is sealed with a liquid sealing structure, and gas leakage can be achieved. The shaft sealing is completed by filling the liquid sealing medium 6 into the liquid sealing chamber. In this way, the sealing problem between the core shaft and the shell of the centrifugal extractor is solved. The centrifugal extractor has a long service life, a reasonable structure, and high safety and reliability. It can not only meet the sealing requirements, but also avoid the volatile substances in the feed liquid in the machine from volatilizing to the outside of the centrifugal extractor to cause material waste and environmental pollution, and overcome the various shortcomings of the above-mentioned traditional sealing technology.

[0033] In the preferred embodiment of this embodiment, Figure 2 As shown, the liquid sealing chamber 5 includes a dynamic sealing chamber 8 and a static sealing chamber 9 which is arranged at the lower end of the dynamic sealing chamber 8 and communicated with the dynamic sealing chamber 8. Specifically, the dynamic sealing chamber 8 is set as a circular ring structure, and the liquid sealing medium 6 is located in the static sealing chamber 9 when the centrifugal extractor is stationary. When the centrifugal extractor rotates, the liquid sealing medium 6 enters the dynamic sealing chamber 8 due to the action of centrifugal force. The cross-sectional shape of the static sealing chamber 9 is a "U"-shaped structure. A baffle is welded along the circumference of the core shaft 3 in the dynamic sealing chamber 8. The baffle includes a horizontal baffle 10 and a vertical baffle 11. The cross-sectional shape forms a "T"-shaped structure, and the vertical baffle 11 extends into the groove of the "U"-shaped structure. Preferably, the vertical baffle 11 is set as a circular ring structure, and a web is provided at the edge of the horizontal baffle 10. The web includes a first web 12 located on the upper end surface of the horizontal baffle 10 and a second web 13 located on the lower end surface of the horizontal baffle 10.

[0034] It should be noted that the length of the first web 12 is greater than the length of the second web 13. Figure 3As shown in the figure, since the centrifugal extractor has centrifugal force when rotating, the centrifugal extractor is in a balanced state when rotating: P 气 +P2=P 壳 +P1, (where P 气 = external gas pressure, P 壳 = pressure inside the shell, P1 = pressure in the chamber where the second web is located, P2 = pressure in the chamber where the first web is located). Generally, nitrogen is filled inside the shell. In order to avoid gas leakage inside the shell, a slightly positive pressure state must be maintained inside the shell, that is, P 壳 >P 气 , at this time, due to P 气 +P2=P 壳 +P1, so it is necessary to satisfy: P2>P1:

[0035] When the rotation speeds W1=W2 in P2 and P1 are the same, the centripetal acceleration g=W 2 r, pressure P = ρgh, (in this embodiment, ρ is the liquid density, g is the centripetal acceleration, and h is the length of the web) to obtain:

[0036] P1=ρ1g1h1, P2=ρ2g2h2, g1=W1 2 r1,g2=W2 2 r2, since r1=r2, therefore: g1= g2,

[0037] The liquid density ρ1=ρ2, so to make P2>P1, it is necessary to make h2>h1, that is, the length of the first web is greater than the length of the second web, so as to ensure that the centrifugal extractor is in a rotating state, P 壳 >P 气 , positive pressure is maintained inside the shell, ensuring that the gas inside the shell cannot leak.

[0038] Further, the number of the first webs 12 is equal to the number of the second webs 13 .

[0039] Preferably, if Figure 1 As shown, the liquid inlet 7 is communicated with the liquid sealing chamber 5 through a liquid inlet channel 14 opened inside the bearing seat 2, and a control valve is provided at the liquid inlet 7 to control the amount and speed of the liquid inlet.

[0040] In addition, if Figure 3 As shown, in order to meet the sealing requirements after the assembly process, an annular groove is provided at the matching installation position between the bearing seat 2 and the housing upper cover plate 1, and an O-ring 15 is installed.

[0041] Furthermore, an upper pressure cover 17 is provided at the upper end of the bearing seat 2. Specifically, the upper pressure cover 17 is connected to the bearing seat 2 by a cylindrical head hexagon socket screw 18. In this way, the structure is stable. Of course, it can also be fixed by other means, depending on the specific situation.

[0042] Furthermore, a cushion block 19 is provided between the upper pressure cover 17 and the core shaft 3, and a first skeleton oil seal structure 20 capable of preventing dust is provided on the inner side wall of the upper pressure cover 17, thereby preventing dust from entering the bearing 4 and extending the service life of the bearing.

[0043] At the same time, in order to extend the service life of the bearing 4, a second skeleton oil seal structure 21 capable of preventing gas from entering is provided on the inner wall of the bearing seat 2 located below the bearing 4.

[0044] In summary, when the centrifugal extractor is in a stationary state, the liquid sealing medium 6 is located in the static sealing chamber 9, and the gas inside the shell 22 cannot leak; when the centrifugal extractor is in an operating state, since the length of the first web 12 is greater than the length of the second web 13, it can ensure that the internal pressure of the shell 22 is greater than the external atmospheric pressure, and the shell 22 maintains a positive pressure state, ensuring that the gas inside the shell 22 cannot leak. Therefore, no matter whether the centrifugal extractor is in a stationary state or an operating state, the gas inside the shell 22 cannot leak, which avoids the volatile substances in the liquid in the machine from volatilizing to the outside of the centrifugal extractor to cause material waste and environmental pollution. The liquid sealing structure in this scheme overcomes the shortcomings of traditional sealing technology, and has a long service life, a reasonable structure, and high safety and reliability.

[0045] The present invention further provides a centrifugal extractor, comprising the liquid sealing structure as described in the above embodiment. The derivation process of this beneficial effect is generally similar to the derivation process of the beneficial effect brought by the above liquid sealing structure, so it will not be repeated herein.

[0046] It should be noted that the words "first" and "second" in this article do not limit the specific order, but are only used to distinguish various components or functions. Figure 1 What it refers to when it is in the placed state.

[0047] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0048] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0049] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A liquid sealing structure for a centrifugal extractor mandrel, the liquid sealing structure being arranged between a housing upper cover plate and a bearing seat of the centrifugal extractor, the centrifugal extractor further comprising a mandrel, and the mandrel vertically passes through the bearing seat and the housing upper cover plate and extends into the interior of the centrifugal extractor, characterized in that: The liquid sealing structure comprises a groove provided on the upper end surface of the upper cover plate of the housing, the groove is arranged along the circumferential direction of the upper end surface of the upper cover plate of the housing, and the upper end of the groove is connected to the bearing seat, a liquid sealing chamber is provided in the groove, a liquid sealing medium is provided in the liquid sealing chamber, and a liquid inlet is provided at the lower part of the bearing seat, which is communicated with the liquid sealing chamber and is used for the liquid sealing medium to enter; The liquid sealing chamber includes a dynamic sealing chamber and a static sealing chamber located at the lower end of the dynamic sealing chamber and connected to the dynamic sealing chamber. The liquid sealing medium is located in the static sealing chamber when the centrifugal extractor is in a stationary state. The cross-sectional shape of the static sealing chamber is a "U"-shaped structure. A baffle is welded along the circumference of the core shaft in the dynamic sealing chamber. The baffle includes a horizontal baffle and a vertical baffle, and the cross-sectional shape forms a "T"-shaped structure. The vertical baffle extends into the groove of the "U"-shaped structure. An upper pressure cover is provided at the upper end of the bearing seat, and the upper pressure cover is fixedly connected to the bearing seat; The vertical baffle is configured as a circular ring structure.

2. The liquid sealing structure for the core shaft of the centrifugal extractor according to claim 1, characterized in that: A web is provided at the edge of the horizontal baffle, and the web includes a first web located at the upper end surface of the horizontal baffle and a second web located at the lower end surface of the horizontal baffle, and the length of the first web is greater than the length of the second web, and the number of the first web is equal to the number of the second web. When the centrifugal extractor is in operation, the liquid sealing medium is located in the dynamic sealing chamber to prevent gas leakage inside the shell.

3. The liquid sealing structure for the core shaft of a centrifugal extractor according to claim 1 or 2, characterized in that: The liquid inlet is communicated with the liquid sealing chamber through a liquid inlet channel opened inside the bearing seat, and a control valve is provided at the liquid inlet.

4. The liquid sealing structure for the core shaft of a centrifugal extractor according to claim 1 or 2, characterized in that: An annular groove is provided at the matching installation position between the bearing seat and the upper cover plate of the housing, and an O-ring is installed therein.

5. The liquid sealing structure for the core shaft of a centrifugal extractor according to claim 1 or 2, characterized in that: The bearing seat is fixedly connected to the housing upper cover plate.

6. The liquid sealing structure for the core shaft of a centrifugal extractor according to claim 1, characterized in that: A cushion block is provided between the upper pressure cover and the core shaft, and the inner side wall of the upper pressure cover is provided with a first skeleton oil seal structure capable of preventing dust and air.

7. The liquid sealing structure for the core shaft of a centrifugal extractor according to claim 1, characterized in that: A bearing is sleeved on the core shaft in the bearing seat, and a second skeleton oil seal structure capable of preventing gas from entering is provided on the inner wall of the bearing seat below the bearing.

8. A centrifugal extractor, comprising a liquid sealing structure, characterized in that: The liquid sealing structure is the liquid sealing structure as described in any one of claims 1-7.

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