Key sealing devices and sealing methods for rotary water ring pumps

Abstract

The present invention belongs to the technical field of liquid ring pumps, and specifically relates to a key sealing device and sealing method for a rotary shell type liquid ring pump, comprising a bracket, a base mounted on the bracket, a pump casing assembled on one side of the base, a sealing shell provided on the side of the pump casing close to the base, and the sealing shell being located on the outside of the base, a bearing provided between the base and the sealing shell, and the base and the pump casing being sealed using any one of the following four sealing structures: a first sealing structure is sealed by a dynamic sealing structure, a second sealing structure is sealed by a magnetic fluid sealing structure, a third sealing structure is sealed by a sealing ring structure, and a fourth sealing structure is sealed by a combination of the above three sealing structures. The present invention can help achieve beneficial effects such as low starting torque, low friction resistance, and high sealing performance, thereby enabling the rotary shell type liquid ring pump to operate with low resistance and high efficiency.

Description

Technical Field

[0001] This invention belongs to the field of liquid ring pump technology, specifically relating to key sealing devices and sealing methods for rotary water ring pumps. Background Technology

[0002] As a type of vacuum pump, water ring pumps play a crucial role in coal mine gas extraction. Since gas is a flammable and explosive gas, the use of vacuum pumps with metal friction surfaces (such as plunger pumps and rotary vane pumps) poses safety hazards. Therefore, water ring pumps, due to their lack of metal friction surfaces, have become the preferred equipment for gas extraction. However, existing water ring pumps suffer from low efficiency and high energy consumption, which contradicts the current national policy of energy conservation and emission reduction.

[0003] Currently, the efficiency of mainstream water ring pumps is generally low, ranging from 15% to 45%, leading to a large waste of energy. For example, the annual power consumption of gas extraction pumping stations in large and medium-sized high-gas mines in my country is very high. Taking Shanxi Lu'an Group as an example, the annual power consumption of more than 400 million kWh of electricity is generated by more than 100 large water ring pumps that are continuously operating in its coal mines. Therefore, improving the efficiency of water ring pumps has become an urgent problem to be solved.

[0004] One of the main reasons for the low efficiency of water ring pumps is the frictional resistance between the high-speed rotating fluid and the stationary pump casing. Studies have shown that frictional power loss accounts for 20%-40% of the total input power of the pump, and this proportion will further increase with the increase of rotational speed. Therefore, reducing the frictional resistance of the pump casing wall is the key to improving the working efficiency of water ring vacuum pumps.

[0005] To address this issue, researchers have attempted to break through the limitations of the traditional "fixed pump casing" design and proposed a new approach of "rotating pump casing." They have also designed a prototype of a rotating water ring pump. Experiments have shown that the high-speed rotating water ring can drive the pump casing to rotate at high speed, effectively reducing wall friction and lowering power consumption.

[0006] However, rotary water ring pumps face new design challenges, especially the dynamic seal between the pump casing and the base (or suction chamber). Traditional dynamic seal devices are difficult to apply to rotary water ring pumps due to issues such as model, size, and resistance, and there is currently no clear method to control the dynamic seal at this point.

[0007] Therefore, this invention proposes a key sealing device and sealing method for a rotating shell water ring pump, aiming to solve the above-mentioned technical problems and improve the overall performance and efficiency of the water ring pump. Summary of the Invention

[0008] The purpose of this invention is to provide a key sealing device and sealing method for a rotary water ring pump, which can help achieve beneficial effects such as low starting torque, low frictional resistance, and high sealing performance, enabling the rotary water ring pump to operate with low resistance and high efficiency.

[0009] The specific technical solution adopted by this invention is as follows:

[0010] A key sealing device and sealing method for a rotary water ring pump includes a bracket, a base mounted on the bracket, a pump casing mounted on one side of the base, a sealing shell disposed on the side of the pump casing near the base, and the sealing shell being located outside the base; a bearing is disposed between the base and the sealing shell.

[0011] The base and the pump casing are sealed using any one of the following four sealing structures: the first sealing structure is a dynamic sealing structure, the second sealing structure is a magnetic fluid sealing structure, the third sealing structure is a sealing ring structure, and the fourth sealing structure is a combination of the above three sealing structures.

[0012] The first sealing structure includes a retaining ring fixed to the outside of the base and located at the end of the bearing near the pump housing. A moving ring is fixed to the side of the pump housing near the retaining ring and located inside the sealing housing. At least one spring is mounted on the side of the retaining ring near the moving ring. A stationary ring is mounted on the end of the spring away from the retaining ring. The stationary ring and the moving ring, as well as the stationary ring and the base, are all in contact with each other.

[0013] The second sealing structure includes two pole shoes fixed to the inner wall of the sealing housing and located at one end of the bearing near the pump housing, and a permanent magnet is installed between the two pole shoes. The inner side of the pole shoes is provided with pole teeth, and magnetic fluid is provided between the pole teeth and the outer wall of the base.

[0014] Each of the two pole shoes is fixed with a water-blocking ring on the side that is far apart from each other. A water-isolating barrier is provided between the water-blocking ring and the outer wall of the base, and an air buffer is provided between the water-isolating barrier and the magnetic fluid.

[0015] The third sealing structure includes an elastic sealing ring disposed between the sealing housing and the base and at the end of the bearing near the pump housing. The elastic sealing ring includes at least one of a skeleton sealing ring, a PTFE sealing ring, and a PTFE seal.

[0016] The fourth sealing structure includes two pole shoes fixed to the inner wall of the sealing housing and located at the end of the bearing near the pump housing. A permanent magnet is assembled between the two pole shoes. Pole teeth are provided on the inner side of the pole shoes. Magnetic fluid is provided between the pole teeth and the outer wall of the base.

[0017] An elastic sealing ring is provided between the sealing housing and the base, and on the side of the pole shoe near the pump housing. The elastic sealing ring includes at least one of a skeleton sealing ring, a PTFE sealing ring, and a PTFE seal.

[0018] A sealing method for a key sealing device in a rotary water ring pump, wherein the sealing method employs a first sealing structure, and the sealing method is as follows:

[0019] By using a spring, the stationary ring is pushed closer to the moving ring, ensuring that the stationary and moving rings are tightly pressed together, thus achieving a seal.

[0020] A sealing method for a key sealing device in a rotary water ring pump, wherein the sealing method employs a second sealing structure, and the sealing method is as follows:

[0021] The magnetic fluid installed at the bottom of the pole teeth can seal the base and the sealing shell. The isolation water prevents the magnetic fluid from leaking. The air buffer between the magnetic fluid and the isolation water separates the magnetic fluid and the isolation water, preventing them from mixing.

[0022] A sealing method for a key sealing device in a rotary water ring pump, which employs a third sealing structure, is described as follows:

[0023] The elastic sealing ring is designed to seal the space between the base and the sealing shell.

[0024] A sealing method for a key sealing device in a rotary water ring pump, which employs a fourth sealing structure, is described as follows:

[0025] The magnetic fluid can seal the space between the outer shell and the base, and the elastic sealing ring further enhances the seal between the two.

[0026] The technical effects achieved by this invention are as follows:

[0027] This invention addresses the problem of achieving "low-resistance sealing" in rotary water ring pumps by designing a sealing device and method with low resistance characteristics. This helps to achieve beneficial effects such as low starting torque, low frictional resistance, and high sealing performance, which in turn helps the rotary water ring pump operate at low resistance and high efficiency, laying the foundation for the stable operation of the rotary water ring pump. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the first sealing structure in this invention;

[0029] Figure 2 This is a schematic diagram of the second sealing structure in this invention;

[0030] Figure 3 This is a schematic diagram of the third sealing structure in this invention;

[0031] Figure 4 This is a schematic diagram of the fourth sealing structure in this invention;

[0032] Figure 5 This is a flowchart of the sealing method in this invention;

[0033] Figure 6 This is a partial structural diagram of the water-retaining ring in the second sealing structure of this invention;

[0034] Figure 7 This is a partial dimensional diagram of the water-retaining ring in the second sealing structure of the present invention.

[0035] The attached diagram lists the components represented by each number as follows:

[0036] 1. Bracket; 2. Base; 3. Bearing; 4. Sealing housing; 5. Pump housing; 8. Elastic sealing ring; 61. Spring; 62. Stationary ring; 63. Dynamic ring; 64. Retaining ring; 71. Permanent magnet; 72. Pole shoe; 73. Pole tooth; 74. Magnetic fluid; 75. Isolation water; 76. Water retaining ring; 77. Air buffer zone; 81. Skeleton sealing ring; 82. PTFE sealing ring; 83. Plug seal. Detailed Implementation

[0037] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0038] like Figures 1-7 As shown, the key sealing device of the rotating shell water ring pump includes a bracket 1, a base 2 mounted on the bracket 1, a pump casing 5 assembled on one side of the base 2, a sealing shell 4 provided on the side of the pump casing 5 near the base 2, and the sealing shell 4 is located outside the base 2. A bearing 3 is provided between the base 2 and the sealing shell 4.

[0039] The base 2 and the pump casing 5 are sealed using any one of the following four sealing structures: the first sealing structure is a dynamic sealing structure, the second sealing structure is a magnetic fluid sealing structure, the third sealing structure is a sealing ring structure, and the fourth sealing structure is a combination of the above three sealing structures. The first sealing structure uses an unconventional mechanical seal device, the second sealing structure uses a magnetic fluid sealing device that has both waterproof and air-tight functions, the third sealing structure uses an elastic sealing device, and the fourth sealing structure is a combination of the above schemes.

[0040] Example 1:

[0041] This embodiment discloses the specific structure and function of the first sealing structure as follows:

[0042] like Figure 1As shown, in a traditional mechanical seal, the stationary ring 62 is fixed to the pump housing 5, while the rotating ring 63 rotates with the shaft. The base 2 is bolted to the bracket 1, and the bearing 3 is mounted and fixed to the base 2. The bearings 3 are positioned together using a sleeve. The first sealing structure includes a retaining ring 64 fixed to the outside of the base 2 and located at the end of the bearing 3 near the pump housing 5. The rotating ring 63 is fixed to the side of the pump housing 5 near the retaining ring 64 and located inside the sealing shell 4. At least one spring 61 is fitted to the side of the retaining ring 64 near the rotating ring 63. When there is only one spring 61, it can be a single spring 61 that surrounds the base 2 as a whole. When there are multiple springs 61, they can be multiple small springs 61. A stationary ring 62 is installed at the end of the spring 61 away from the retaining ring 64. The stationary ring 62 and the rotating ring 63, as well as the stationary ring 62 and the base 2, are in close contact with each other. The stationary ring 62 and the base 2 are sealed by a static sealing ring or elastic rubber, etc. The rotating ring 63 and the pump housing 5 are sealed by a static sealing ring. The stationary ring 62 and the rotating ring 63 are sealed by the contact surface, thus achieving the dynamic sealing function.

[0043] During sealing, the spring 61 is designed to make the stationary ring 62 move closer to the rotating ring 63, and make the stationary ring 62 and the rotating ring 63 fit tightly together, thereby achieving a sealing effect.

[0044] The method for controlling the preload is as follows: Using experimental methods or empirical formulas, adjust the preload under different pressure differential conditions. When the leakage rate reaches the set threshold, record the preload value and determine the relationship between the preload and the pressure differential. Simultaneously, determine the relationship between the frictional resistance and the preload. Determine the preload based on the relationship between the preload and the pressure differential, and determine the number of springs, the elastic coefficient, and the compression amount based on the magnitude of the preload.

[0045] Example 2:

[0046] This embodiment discloses the specific structure and function of the second sealing structure as follows:

[0047] See appendix Figure 2 and attached Figure 6 As shown, the sealing shell 4 and the pump shell 5 are fixed relative to each other. The sealing shell 4 rotates together with the pump shell 5. The sealing shell 4 is rotatably connected to the base 2 through the bearing 3. The base 2 is fixedly connected to the bracket 1. Functional holes are provided in the base 2, such as shaft holes, air intake holes, air exhaust holes, water injection holes, etc. The base 2 is fixedly connected to the bracket 1 by bolts. The bearing 3 is installed and fixed on the base 2. The positioning of the bearings 3 is achieved by a sleeve.

[0048] The second sealing structure includes two pole shoes 72 fixed to the inner wall of the sealing housing 4 and located at the end of the bearing 3 near the pump housing 5, and a permanent magnet 71 is installed between the two pole shoes 72. Pole teeth 73 are provided on the inner side of the pole shoes 72, and magnetic fluid 74 is provided between the pole teeth 73 and the outer wall of the base 2 to form a magnetic fluid sealing ring.

[0049] Water-blocking rings 76 are fixed on the opposite sides of the two pole shoes 72. Water-isolating water 75 is provided between the water-blocking rings 76 and the outer wall of the base 2. Water is injected into the water-blocking rings 76 to isolate the water 75. An air buffer zone 77 is provided between the water-isolating water 75 and the magnetic fluid 74. The air buffer zone 77 separates the magnetic fluid 74 from the right-side water-isolating water 75. A static sealing ring is installed between the water-blocking rings 76 and the pole shoes 72 to prevent air leakage.

[0050] See appendix Figure 7 The inner side of the water-blocking ring 76 is stepped. The distances between the inner surface of the water-blocking ring 76 and the outer surface of the base 2 are H1 and H2, respectively. The part with the distance H1 is filled with an air buffer 77, and the part with the distance H2 is filled with an isolation water 75. The air buffer 77 in the water-blocking ring 76 separates the magnetic fluid 74 and the isolation water 75, preventing water in the pump from contaminating and damaging the magnetic fluid 74. Overall, the water-blocking ring 76 has the function of waterproofing and airproofing. The outer side of the permanent magnet 71 is wound with a coil. When the coil is energized, it can generate a magnetic field opposite to that of the permanent magnet 71. When the equipment is started, energizing the coil can reduce the resistance of the magnetic fluid 74 and reduce the starting torque.

[0051] The magnetic fluid 74 provided at the lower part of the pole teeth 73 can seal the base 2 and the sealing shell 4. The isolation water 75 can prevent the magnetic fluid 74 from leaking. The air buffer 77 provided between the magnetic fluid 74 and the isolation water 75 can separate the magnetic fluid 74 and the isolation water 75, preventing them from mixing and thus preventing external water from contaminating the magnetic fluid 74.

[0052] Furthermore, dimension H1 is smaller than H2, and dimension L1 is smaller than L2.

[0053] Magnetic force control method: First, based on the required internal and external pressure difference, select a suitable permanent magnet 71 and magnetic fluid 74. Determine the magnetic field strength inside the magnetic fluid 74 according to the magnetic field strength and the number and size of the pole teeth 73. Combined with the magnetism of the magnetic fluid 74, calculate and determine the magnetic force. The magnetic force can also be measured experimentally. In addition, the resistance of the magnetic fluid 74 on the pump casing 5 when it rotates can be measured experimentally.

[0054] Example 3:

[0055] This embodiment discloses the specific structure and function of the third sealing structure as follows:

[0056] Reference Appendix Figure 4The base 2 is fixedly connected to the bracket 1 by bolts, and the bearing 3 is installed and fixed on the base 2. The positioning of the bearings 3 is achieved by a sleeve. The third sealing structure includes an elastic sealing ring 8 between the sealing shell 4 and the base 2 and located at the end of the bearing 3 near the pump shell 5. The elastic sealing ring 8 includes at least one of the skeleton sealing ring 81, PTFE sealing ring 82 and PTFE seal 83.

[0057] The elastic sealing ring 8 is designed to seal the space between the base 2 and the sealing housing 4.

[0058] Dynamic friction control method: Based on the pressure difference between the inside and outside of the water ring pump, the dynamic friction resistance is minimized under the premise of ensuring sealing. The pre-tightening force of the elastic sealing ring 8 is determined according to this principle by controlling the pre-compression amount and the elastic coefficient, or by experimental determination.

[0059] Example 4:

[0060] This embodiment discloses the specific structure and function of the fourth sealing structure as follows:

[0061] Reference Appendix Figure 4 The base 2 is fixedly connected to the bracket 1 by bolts, and the bearing 3 is installed and fixed on the base 2. The positioning of the bearings 3 is achieved by a sleeve. The fourth sealing structure includes two pole shoes 72 fixed to the inner wall of the sealing shell 4 and located at the end of the bearing 3 near the pump shell 5. A permanent magnet 71 is assembled between the two pole shoes 72. Pole teeth 73 are provided on the inner side of the pole shoes 72. Magnetic fluid 74 is provided between the pole teeth 73 and the outer wall of the base 2.

[0062] An elastic sealing ring 8 is provided between the sealing housing 4 and the base 2 and on the side of the pole shoe 72 near the pump housing 5, and the elastic sealing ring 8 includes at least one of the skeleton sealing ring 81, PTFE sealing ring 82 and PTFE plug seal 83.

[0063] This configuration allows the magnetic fluid 74 to seal between the sealing shell 4 and the base 2, and the elastic sealing ring 8 further enhances the sealing effect between the two.

[0064] See appendix Figure 5The sealing type is determined comprehensively based on the internal and external pressure difference requirements of the water ring pump and the sealing and resistance performance of each stage of the seal. Using a threshold leakage rate, such as 0.01%, as a benchmark, the sealing pressure difference borne by the sealing device is denoted as dp. At this pressure difference, the leakage rate of the sealing device is 0.01%, and the corresponding wasted power consumed by the frictional resistance is denoted as Pf. The ratio dp / Pf characterizes the quality of the sealing device; a larger value indicates better sealing and lower losses. Since dp / Pf is not a constant value for different sealing devices, it depends on factors such as dp and rotational speed. Therefore, under different pressure difference dp conditions, it is necessary to rationally select the sealing type to minimize sealing resistance while ensuring a good seal.

[0065] First, determine whether a single-stage or multi-stage seal is required based on the sealing requirements. If it's a single-stage seal, determine the seal type and choose Option 1, Option 2, or Option 3. If a multi-stage seal is chosen, select Option 4. Each option primarily achieves seal control by adjusting the preload or magnetic field force.

[0066] The principle for adjusting the preload of the mechanical seal in Scheme 1 is to minimize frictional resistance under specific internal and external pressure difference conditions while ensuring sealing. Based on this principle, the preload of spring 61 in the mechanical seal is determined, and the preload of spring 61 is controlled by controlling the number of springs 61, their elastic coefficient, and their compression.

[0067] In Scheme Two, the magnetic field force control method involves calculating and determining the magnetic field strength of the permanent magnet 71, the number of pole teeth 73, and the distance between the pole teeth 73 and the inner shell of the magnetic seal, based on the pressure difference between the inside and outside of the water ring pump. If the starting torque is too large, a reverse magnetic field is applied through the energized coil to overcome it.

[0068] In Scheme 3, the dynamic friction force control method is as follows: based on the pressure difference between the inside and outside of the water ring pump, the dynamic friction resistance is minimized under the premise of ensuring sealing. The pre-tightening force of the elastic sealing ring 8 is determined according to this principle by controlling the pre-compression amount and the elastic coefficient, or by experimental determination.

[0069] The sealing method in Option 4 is to adopt a multi-stage combined sealing method. Based on the internal pressure difference conditions of the water ring pump, the total pressure difference dp is decomposed and distributed to each stage of the seal, dp = dp2 + dp3. The sealing parameters of each stage are determined according to the pressure difference requirements of each stage of the seal. The specific sealing parameters are the same as those in the first three options.

[0070] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention are implemented according to conventional methods in the art unless otherwise specified or limited.

Claims

1. A key sealing device for a rotary water ring pump, comprising a bracket (1), characterized in that: A base (2) is installed on the bracket (1). A pump housing (5) is assembled on one side of the base (2). A sealing shell (4) is provided on the side of the pump housing (5) near the base (2). The sealing shell (4) is located outside the base (2). A bearing (3) is provided between the base (2) and the sealing shell (4). The base (2) and the pump casing (5) are sealed by a second sealing structure, which is sealed by a magnetic fluid sealing structure. The second sealing structure includes two pole shoes (72) fixed to the inner wall of the sealing housing (4) and located at one end of the bearing (3) near the pump housing (5), and a permanent magnet (71) is installed between the two pole shoes (72). The inner side of the pole shoes (72) is provided with pole teeth (73), and a magnetic fluid (74) is provided between the pole teeth (73) and the outer wall of the base (2). Water-blocking rings (76) are fixed on the opposite sides of the two pole shoes (72). Water-blocking rings (76) are provided between the water-blocking rings (76) and the outer wall of the base (2). An air buffer zone (77) is provided between the water-blocking rings (76) and the magnetic fluid (74).

2. The key sealing device for a rotating casing water ring pump according to claim 1, characterized in that: The base (2) and the pump casing (5) are also sealed using a fourth sealing structure; The fourth sealing structure is a combination of the first sealing structure, the second sealing structure, and the third sealing structure; The first sealing structure is sealed by a dynamic sealing structure, and the third sealing structure is sealed by a sealing ring structure.

3. The key sealing device for a rotating casing water ring pump according to claim 2, characterized in that: The first sealing structure includes a retaining ring (64) fixed on the outside of the base (2) and located at one end of the bearing (3) near the pump housing (5). A moving ring (63) is fixed on the side of the pump housing (5) near the retaining ring (64) and located on the inside of the sealing housing (4). At least one spring (61) is fitted on the side of the retaining ring (64) near the moving ring (63). A stationary ring (62) is installed on the end of the spring (61) away from the retaining ring (64). The stationary ring (62) and the moving ring (63) and the stationary ring (62) and the base (2) are all in contact with each other.

4. The key sealing device for a rotating casing water ring pump according to claim 2, characterized in that: The third sealing structure includes an elastic sealing ring (8) disposed between the sealing housing (4) and the base (2) and located at the end of the bearing (3) near the pump housing (5). The elastic sealing ring (8) includes at least one of a skeleton sealing ring (81), a PTFE sealing ring (82), and a PTFE seal (83).

5. The key sealing device for a rotating casing water ring pump according to claim 2, characterized in that: The fourth sealing structure includes two pole shoes (72) fixed to the inner wall of the sealing housing (4) and located at one end of the bearing (3) near the pump housing (5). A permanent magnet (71) is assembled between the two pole shoes (72). Pole teeth (73) are provided on the inner side of the pole shoes (72). Magnetic fluid (74) is provided between the pole teeth (73) and the outer wall of the base (2). An elastic sealing ring (8) is provided between the sealing housing (4) and the base (2) and on the side of the pole shoe (72) near the pump housing (5), and the elastic sealing ring (8) includes at least one of the skeleton sealing ring (81), PTFE sealing ring (82) and PTFE seal (83).

6. A sealing method for a key sealing device in a rotary water ring pump, characterized in that: The sealing method employs the second sealing structure in the key sealing device of the rotating shell water ring pump as described in claim 1, and the sealing method is as follows: A magnetic fluid (74) is provided at the lower part of the pole tooth (73) to seal the space between the base (2) and the sealing shell (4); An isolation water (75) is provided between the water-blocking ring (76) and the outer wall of the base (2) to prevent the leakage of magnetic fluid (74). An air buffer (77) is provided between the magnetic fluid (74) and the isolation water (75) to separate the magnetic fluid (74) and the isolation water (75).

7. A sealing method for a key sealing device in a rotary water ring pump, characterized in that: The sealing method employs the fourth sealing structure in the key sealing device of the rotating shell water ring pump as described in claim 5, and the sealing method is as follows: The magnetic fluid (74) can seal the space between the sealing shell (4) and the base (2), and the elastic sealing ring (8) can seal again by setting the elastic sealing ring (8).

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