Orifice ring sealing device for centrifugal pump and centrifugal pump

Abstract

This invention provides a centrifugal pump inlet ring sealing device and a centrifugal pump, including a rotating ring and a stationary ring disposed between the inlet ring and the impeller front cover. The spacing between two adjacent sets of stationary ring teeth is B. c The distance between the inner circumferential surface of the stationary ring and the outer circumferential surface of the moving ring is H. t The moving ring tooth has a "dry" shaped cross-section, comprising radially extending radial ring teeth, a first axial ring tooth perpendicular to the radial ring teeth and parallel to each other, and a second axial ring tooth. The distance H between the first axial ring tooth and the second axial ring tooth is... b =0.05H t ~0.35H t The distance H between the first axial ring tooth and the outer circumferential surface of the moving ring. a =0.05H t ~0.35H t The tooth thickness B of the radial ring tooth in the axial direction. a =0.1B c ~0.4B c The tooth width H of the first axial ring tooth and the second axial ring tooth in the radial direction v =0.1H t ~0.2H t The distance C between the first axial ring tooth, the second axial ring tooth, and the adjacent stationary ring teeth on both sides. s =0.1B c ~0.25B c This invention increases the eddy current loss inside the sealing chamber by adjusting the moving ring tooth structure, thereby significantly reducing fluid leakage at the mouth ring under high-pressure conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of centrifugal pumps, in particular to a mouth ring sealing device of a centrifugal pump and the centrifugal pump. BACKGROUND

[0002] A centrifugal pump is a fluid conveying device widely used in industrial fields. Its working principle mainly relies on the rotation of the impeller to generate centrifugal force, thereby sucking fluid from the inlet and accelerating it to the outlet. In the structure of the centrifugal pump, the mouth ring is a key sealing component, which is arranged at the gap between the pump shell and the impeller front cover and is fixedly connected with the pump shell. The main function of the mouth ring is to prevent fluid from leaking from the high-pressure area to the low-pressure area, ensuring the efficient operation of the pump.

[0003] The mouth ring is usually made of wear-resistant and corrosion-resistant materials to withstand the friction and pressure generated by the fluid during high-speed rotation. Under normal operating conditions, the design of the mouth ring gap needs to ensure that it can effectively prevent leakage and allow the impeller to have a certain space for movement when it expands or wears. However, in actual application, especially under high-pressure working conditions, the leakage problem at the mouth ring gap becomes particularly prominent. Under high-pressure working conditions, the pressure of the fluid on the mouth ring gap increases, resulting in a significant increase in leakage. Leakage not only reduces the efficiency of the pump and increases energy consumption, but also can cause pollution to the surrounding environment and even cause safety accidents. Therefore, how to effectively control the leakage of the mouth ring gap under high-pressure working conditions has become an important problem in the design and maintenance of centrifugal pumps. SUMMARY

[0004] In view of the problem of increased leakage at the mouth ring of a centrifugal pump under high-pressure working conditions, the present application provides a mouth ring sealing device of a centrifugal pump and the centrifugal pump, which adjusts the dynamic ring tooth structure to increase the eddy current loss inside the sealing chamber, thereby greatly reducing the leakage of the fluid at the mouth ring under high-pressure working conditions.

[0005] The present application achieves the above technical purposes through the following technical means.

[0006] A mouth ring sealing device of a centrifugal pump, characterized in that the mouth ring is arranged at the gap between the pump shell and the impeller front cover of the centrifugal pump and is fixedly connected with the pump shell; the mouth ring sealing device comprises a dynamic ring and a static ring arranged between the mouth ring and the impeller front cover; the static ring is sleeved on the impeller front cover and is fixedly connected with the mouth ring, and a plurality of static ring teeth are arranged on the inner circumferential surface of the static ring near the impeller front cover in the axial direction; the dynamic ring is sleeved on the impeller front cover and is fixedly connected with the impeller front cover, and a plurality of dynamic ring teeth are arranged on the outer circumferential surface of the dynamic ring near the mouth ring in the axial direction, which are staggered with the static ring teeth; the distance between two adjacent groups of static ring teeth is B c , and the distance between the inner circumferential surface of the static ring and the outer circumferential surface of the dynamic ring is H tThe cross section of the moving ring tooth is in the shape of "dry", including radially extending radial ring tooth, first axial ring tooth perpendicular to the radial ring tooth and parallel to each other, and second axial ring tooth; the interval of the first axial ring tooth and the second axial ring tooth is H b , H b =0.05H t ~0.35H t ; the interval of the first axial ring tooth and the outer circumferential surface of the moving ring is H a , H a =0.05H t ~0.35H t ; the tooth thickness of the radial ring tooth in the axial direction is B a , B a =0.1B c ~0.4B c ; the tooth width of the first axial ring tooth and the second axial ring tooth in the radial direction is H v , H v =0.1H t ~0.2H t ; the interval of the first axial ring tooth, the second axial ring tooth and the adjacent two side static ring teeth is C s , C s =0.1B c ~0.25B c .

[0007] Further, the interval of the first axial ring tooth and the second axial ring tooth is H b =0.05H t ~0.2H t ; the interval of the first axial ring tooth and the outer circumferential surface of the moving ring is H a =0.2H t ~0.35H t .

[0008] Further, the interval of the first axial ring tooth and the second axial ring tooth is H b =0.15H t ~0.2H t , the interval of the first axial ring tooth and the outer circumferential surface of the moving ring is H a =0.3H t ~0.35H t , the tooth thickness of the radial ring tooth in the axial direction is B a =0.3B c ~0.4B c , the tooth width of the first axial ring tooth and the second axial ring tooth in the radial direction is H v =0.16H t ~0.2H t , and the interval of the second axial ring tooth and the adjacent two side static ring teeth is C s= 0.1B c ~ 0.15B c .

[0009] Further, the distance between the second axial ring tooth and the inner circumferential surface of the static ring is C a , C a ≥ 0.03H t .

[0010] Further, a third axial ring tooth is arranged between the inner circumferential surface of the static ring and the second axial ring tooth; that is:

[0011] The third axial ring tooth is arranged in the middle of the inner circumferential surface of the static ring close to the second axial ring tooth;

[0012] Alternatively, the third axial ring tooth is arranged in the middle of the outer circumferential surface of the second axial ring tooth close to the static ring.

[0013] Further, the tooth thickness of the third axial ring tooth in the axial direction is B n , B n = B a ; the tooth width of the third axial ring tooth in the radial direction is H n , H n = 0.04H t ~ 0.1H t , and H n ≤ C a .

[0014] Further, the distance between the static ring tooth and the outer circumferential surface of the dynamic ring is C r , C r = 0.05H t ~ 0.2H t ; the tooth thickness of the static ring tooth in the axial direction is B s , B s = 0.2B c ~ 0.4B c .

[0015] Further, H t is 2-5mm, and B c is 2-5mm.

[0016] Further, the number of static ring teeth is not less than 3, and the number of dynamic ring teeth is not less than 2.

[0017] A centrifugal pump with the above-mentioned ring seal device.

[0018] The beneficial effects of the present application are as follows:

[0019] 1. The "dry" type of ring teeth in the present invention subdivides the originally large cavity into multiple small cavities. This change not only increases the number of dissipation chambers, but also increases the frequency of internal vortex generation. By increasing the number of vortexes, the pressure energy of high-pressure fluid can be more effectively converted into heat energy, thereby reducing the energy of the fluid through heat dissipation to achieve the effect of reducing leakage. This means that even under high-pressure working conditions, the ring seal device can maintain a low leakage level, demonstrating excellent sealing performance. This improvement has important practical significance for improving the efficiency of centrifugal pumps, prolonging the service life of equipment, and ensuring operational safety, and therefore has very broad market application prospects.

[0020] 2. The present invention optimizes the ring seal device by studying the influence of various structural parameters (H a , H b , B a , H v , C s ) on leakage. The optimized ring seal device not only narrows the gap, increases entropy, and increases energy dissipation, thereby significantly enhancing the leakage prevention effect, but also reduces the average speed of the fluid in the chamber by reducing the gap, weakening the inertial effect, and further reducing the leakage of high-pressure fluid. In addition, the optimized design cleverly balances the gap size, avoiding component collisions due to a too small gap and manufacturing difficulties caused by excessively high processing precision.

[0021] 3. The present invention adds a third axial ring tooth to the "dry" type of ring teeth, further dividing the cavity between the "dry" type of ring teeth and the static ring teeth into left and right chambers. This not only further refines the fluid flow path and enhances the resistance experienced by the fluid when passing through the sealing structure, but also promotes the formation of more vortexes, thereby strengthening the dissipation effect during the energy conversion process. The design of the third axial ring tooth enhances the ability of the sealing structure to withstand high-pressure environments, allowing it to maintain good sealing and stability under extreme conditions. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 Structure diagram of the centrifugal pump with a ring seal device as described in Example 1.

[0023] Figure 2 Structure diagram of the ring seal device of the centrifugal pump as described in Example 1.

[0024] Figure 3 Structure diagram of the ring seal device of the centrifugal pump as described in Example 2.

[0025] Figure 4 Structure diagram of the ring seal device of the centrifugal pump as described in Example 3.

[0026] Figure 5 Structure diagram of the port ring sealing device of the centrifugal pump described in Example 4.

[0027] Figure 6 Structure diagram of the port ring sealing device of the centrifugal pump described in Example 5.

[0028] Figure 7 Structure diagram of the port ring sealing device of the centrifugal pump described in Example 6.

[0029] Figure 8 Structure diagram of the port ring sealing device of the centrifugal pump described in Comparative Experiment 1.

[0030] Figure 9 Structure diagram of the port ring sealing device of the centrifugal pump described in Comparative Experiment 2.

[0031] Figure 10 Structure diagram of the port ring sealing device of the centrifugal pump described in Comparative Experiment 3.

[0032] Figure 11 Structure diagram of the port ring sealing device of the centrifugal pump described in Comparative Experiment 4.

[0033] Figure 12 Comparison diagram of the leakage amount of the 10 port ring sealing devices in Examples 1-6 and Comparative Experiments 1-4.

[0034] The reference signs are as follows:

[0035] 1 - moving ring; 2 - stationary ring; 3 - moving ring tooth; 31 - first axial ring tooth; 32 - second axial ring tooth; 33 - radial ring tooth; 4 - stationary ring tooth; 5 - third axial ring tooth; 6 - pump shell; 7 - impeller front cover; 8 - port ring. DETAILED DESCRIPTION

[0036] The application will be further described below in conjunction with the drawings and specific examples, but the protection scope of the application is not limited thereto.

[0037] Example 1

[0038] The port ring sealing device of the centrifugal pump described in this example comprises a moving ring 1 and a stationary ring 2 arranged between a port ring 8 and an impeller front cover 7 of the centrifugal pump, the port ring 8 is arranged at the gap between a pump shell 6 and the impeller front cover 7 of the centrifugal pump and is fixedly connected with the pump shell 6, Figure 1 Structure diagram of the centrifugal pump with the port ring sealing device described in this example.

[0039] The static ring 2 is sleeved on the impeller front cover 7 and fixedly connected with the port ring 8, and a plurality of static ring teeth 4 are arranged on the inner circumferential surface of the static ring 2 close to the impeller front cover 7 in the axial direction. The dynamic ring 1 is sleeved on the impeller front cover 7 and fixedly connected with the impeller front cover 7, and a plurality of dynamic ring teeth 3 are arranged on the outer circumferential surface of the dynamic ring 1 close to the port ring 8 in the axial direction. The distance between the two adjacent groups of static ring teeth 4 is B c , the distance between the inner circumferential surface of the static ring 2 and the outer circumferential surface of the dynamic ring 1 is H t , H t = 3mm in the embodiment, and B c = 3mm. Figure 2 The port ring sealing device suitable for the centrifugal pump is described in the embodiment.

[0040] The cross section of the dynamic ring tooth 3 is in the shape of "dry", including the radial ring tooth 33 extending in the radial direction, the first axial ring tooth 31 and the second axial ring tooth 32 perpendicular to the radial ring tooth 33 and parallel to each other. The number of static ring teeth is N1, the number of dynamic ring teeth is N2, the distance between the static ring teeth and the outer circumferential surface of the dynamic ring is C r , the tooth thickness of the static ring teeth in the axial direction is B s , the distance between the first axial ring tooth 31 and the second axial ring tooth 32 is H b, , the distance between the first axial ring tooth 31 and the outer circumferential surface of the dynamic ring 1 is H a , the tooth thickness of the radial ring tooth 33 in the axial direction is B a , the tooth width of the first axial ring tooth 31 and the second axial ring tooth 32 in the radial direction is H v , the distance between the first axial ring tooth 31, the second axial ring tooth 32 and the two adjacent static ring teeth 4 is C s , and the distance between the second axial ring tooth 32 and the inner circumferential surface of the static ring 2 is C a . The port ring sealing device described in the embodiment is recorded as the A-type port ring sealing device, and the specific values are shown in Table 1.

[0041] Table 1 Structure parameters of the A-type port ring sealing device

[0042]

[0043] Further, the embodiment also includes a centrifugal pump assembled with the above-mentioned port ring sealing device.

[0044] Embodiment 2

[0045] The port ring sealing device suitable for the centrifugal pump described in the embodiment is only different from that of embodiment 1 in that the distance H a = 0.17H t between the first axial ring tooth 31 and the outer circumferential surface of the dynamic ring 1, the distance H b= 0.33H t The rest of the structure and parameters are unchanged, Figure 3 is a structural schematic diagram of the port ring sealing device suitable for a centrifugal pump according to the embodiment. The port ring sealing device according to the embodiment is recorded as a B-type port ring sealing device.

[0046] Embodiment 3

[0047] The port ring sealing device suitable for a centrifugal pump according to the embodiment is different from that of embodiment 1 only in that a third axial ring tooth 5 is further arranged between the inner circumferential surface of the static ring 2 and the second axial ring tooth 32, the third axial ring tooth 5 is arranged in the middle of the outer circumferential surface of the second axial ring tooth 32 close to the side of the static ring 2, the tooth thickness of the third axial ring tooth 5 in the axial direction is B n , B n = B a , the tooth width of the third axial ring tooth 5 in the radial direction is H n , H n = 0.07H t The rest of the structure and parameters are unchanged, Figure 4 is a structural schematic diagram of the port ring sealing device suitable for a centrifugal pump according to the embodiment. The port ring sealing device according to the embodiment is recorded as an A lower dot type port ring sealing device.

[0048] Embodiment 4

[0049] The port ring sealing device suitable for a centrifugal pump according to the embodiment is different from that of embodiment 1 only in that a third axial ring tooth 5 is further arranged between the inner circumferential surface of the static ring 2 and the second axial ring tooth 32, the third axial ring tooth 5 is arranged in the middle of the inner circumferential surface of the static ring 2 close to the side of the second axial ring tooth 32, the tooth thickness of the third axial ring tooth 5 in the axial direction is B n , B n = B a , the tooth width of the third axial ring tooth 5 in the radial direction is H n , H n = 0.07H t The rest of the structure and parameters are unchanged, Figure 5 is a structural schematic diagram of the port ring sealing device suitable for a centrifugal pump according to the embodiment. The port ring sealing device according to the embodiment is recorded as an A upper dot type port ring sealing device.

[0050] Embodiment 5

[0051] The port ring sealing device suitable for a centrifugal pump according to the embodiment is different from that of embodiment 2 only in that a third axial ring tooth 5 is further arranged between the inner circumferential surface of the static ring 2 and the second axial ring tooth 32, the third axial ring tooth 5 is arranged in the middle of the outer circumferential surface of the second axial ring tooth 32 close to the side of the static ring 2, the tooth thickness of the third axial ring tooth 5 in the axial direction is Bn B n B a The tooth width of the third axial ring tooth 5 in the radial direction is H n H n = 0.07H t The rest of the structure and parameters remain unchanged, Figure 6 The structure diagram of the port ring sealing device suitable for the centrifugal pump is shown in this embodiment, and the port ring sealing device in this embodiment is recorded as the B lower point type port ring sealing device.

[0052] Embodiment 6

[0053] The port ring sealing device suitable for the centrifugal pump in this embodiment is different from that in embodiment 2 only in that a third axial ring tooth 5 is further arranged between the inner circumferential surface of the static ring 2 and the second axial ring tooth 32, the third axial ring tooth 5 is arranged in the middle of the inner circumferential surface of the static ring 2 close to the side of the second axial ring tooth 32, and the tooth thickness of the third axial ring tooth 5 in the axial direction is B n B n B a The tooth width of the third axial ring tooth 5 in the radial direction is H n H n = 0.07H t The rest of the structure and parameters remain unchanged, Figure 7 The structure diagram of the port ring sealing device suitable for the centrifugal pump is shown in this embodiment, and the port ring sealing device in this embodiment is recorded as the B lower point type port ring sealing device.

[0054] In order to verify that the port ring sealing device suitable for the centrifugal pump has better sealing performance, the following four groups of comparative experiments are designed.

[0055] Comparative experiment 1

[0056] The port ring sealing device in this comparative experiment is different from that in embodiment 1 in that the dynamic ring tooth is cancelled, and the rest of the structure and parameters remain unchanged, Figure 8 The structure diagram of the port ring sealing device suitable for the centrifugal pump is shown in this comparative experiment, and the port ring sealing device in this comparative experiment is recorded as the straight-through type port ring sealing device.

[0057] Comparative experiment 2

[0058] The port ring sealing device in this comparative experiment is different from that in embodiment 1 in that the dynamic ring tooth in this comparative experiment is a radial ring tooth, the tooth thickness of the radial ring tooth in the axial direction is B r = 0.33B c The distance C between the radial ring tooth and the adjacent two sides of the static ring tooth is s = 0.1B c The tooth width H of the radial ring tooth in the radial directionr = 0.33H t , the rest of the structure and parameters are unchanged, Figure 9 is a structure diagram of the port ring sealing device suitable for a centrifugal pump in the present comparative experiment, and the port ring sealing device in the present comparative experiment is recorded as a staggered port ring sealing device.

[0059] Comparative Experiment 3

[0060] The port ring sealing device in the present comparative experiment is different from that in Example 1 in that the cross section of the dynamic ring tooth in the present comparative experiment is T-shaped, including a radial ring tooth extending in the radial direction and an axial ring tooth perpendicular to the radial ring tooth. The distance H between the axial ring tooth and the outer circumferential surface of the dynamic ring a = 0.33H t , the tooth thickness B of the radial ring tooth in the axial direction a = 0.33B c , the tooth width H of the axial ring tooth in the radial direction v = 0.17H t , the distance C between the axial ring tooth and the adjacent two side static ring teeth s = 0.1B c , the rest of the structure and parameters are unchanged, Figure 10 is a structure diagram of the port ring sealing device suitable for a centrifugal pump in the present comparative experiment, and the port ring sealing device in the present comparative experiment is recorded as a large T-shaped port ring sealing device.

[0061] Comparative Experiment 4

[0062] The port ring sealing device in the present comparative experiment is different from that in Example 1 in that the cross section of the dynamic ring tooth in the present comparative experiment is T-shaped, including a radial ring tooth extending in the radial direction and an axial ring tooth perpendicular to the radial ring tooth. The distance H between the axial ring tooth and the outer circumferential surface of the dynamic ring a = 0.17H t , the tooth thickness B of the radial ring tooth in the axial direction a = 0.33B c , the tooth width H of the axial ring tooth in the radial direction v = 0.17H t , the distance C between the axial ring tooth and the adjacent two side static ring teeth s = 0.1B c , the rest of the structure and parameters are unchanged, Figure 11 is a structure diagram of the port ring sealing device suitable for a centrifugal pump in the present comparative experiment, and the port ring sealing device in the present comparative experiment is recorded as a small T-shaped port ring sealing device.

[0063] The CFD related simulation software is adopted to simulate and calculate the leakage (unit: kg·s) of the ten kinds of mouth ring sealing devices in the examples 1-6 and the comparative experiments 1-4 under different inlet and outlet pressure differences, and the performance is compared, Figure 12 The leakage simulation comparison chart of the ten kinds of mouth ring sealing devices in the examples 1-6 and the comparative experiments 1-4 is shown in the figure. Figure 12 According to the simulation results of the figure, it can be obviously observed that the leakage of the mouth ring sealing devices in the examples 1-6 under various pressure difference conditions is always lower than that of the mouth ring sealing devices in the comparative experiments 1-4, wherein the sealing performance of the B upper point type mouth ring sealing device is the best. Table 2 is a specific leakage comparison table of the simulation results. Figure 12

[0064] Table 2 Leakage comparison table

[0065]

[0066] It can be seen from table 6 that compared with the straight-through type mouth ring sealing device in the comparative experiment 1, the leakage of the mouth ring sealing device suitable for the centrifugal pump can be reduced by 63.7% at most. Compared with the staggered type mouth ring sealing device in the comparative experiment 2, the leakage of the mouth ring sealing device suitable for the centrifugal pump can be reduced by 22.6% at most. Compared with the large T type mouth ring sealing device in the comparative experiment 3, the leakage of the mouth ring sealing device suitable for the centrifugal pump can be reduced by 17.4% at most. Compared with the small T type mouth ring sealing device in the comparative experiment 4, the leakage of the mouth ring sealing device suitable for the centrifugal pump can be reduced by 18% at most. Meanwhile, among the six kinds of mouth ring sealing devices in the examples 1-6, the sealing performance of the mouth ring sealing device with the third axial ring tooth 5 (A lower point type, A upper point type, B lower point type, B upper point type) is better than that of the mouth ring sealing device without the third axial ring tooth 5 (A type, B type), and the leakage of the third axial ring tooth 5 located in the middle of the inner circumferential surface of the static ring 2 close to the side of the second axial ring tooth 32 (B upper point type) is the lowest.

[0067] In order to further study the influence of various structural parameters (H a , H b , B a , H v , C s ) on the leakage, the example 1 is subjected to a five-factor four-level orthogonal test, wherein the ratio of each factor to the axial length B c or the radial height H t of the sealing cavity surrounded by the adjacent two groups of static ring teeth 4 and the simulation results under high pressure working condition are shown in table 3.

[0068] Table 3 Simulation results​

[0069]

[0070]

[0071] From the above table, it can be seen that the above-mentioned 5 parameters have a nonlinear relationship with the leakage amount of the high-pressure fluid. Through range comparison, it is found that C S has the most significant impact on the leakage amount, and the parameter combination shown by the fourth group (i.e., C s = 0.1B c , B a = 0.4B c , H a = 0.35H t , H v = 0.2H t , and H b = 0.2H t ) has the optimal throttling efficiency under high-pressure working conditions, and the leakage amount is reduced by 46.6% compared with other parameter combinations. Therefore, the present application further improves the above-mentioned parameters on the basis of the "dry" type dynamic ring tooth 3 mechanism, so that the port ring sealing device exhibits more excellent sealing performance under high-pressure working conditions, and further realizes the low-leakage target.

[0072] The embodiments are preferred embodiments of the present application, but the present application is not limited to the above-mentioned embodiments. Any obvious improvement, replacement or modification made by those skilled in the art without departing from the essential content of the present application shall fall within the protection scope of the present application.

Claims

1. A mechanical seal for a centrifugal pump, comprising: The mouth ring (8) is arranged at the gap between the pump shell (6) and the impeller front cover (7) of the centrifugal pump and is fixedly connected with the pump shell (6); the mouth ring sealing device comprises a movable ring (1) and a static ring (2) arranged between the mouth ring (8) and the impeller front cover (7); the static ring (2) is sleeved on the impeller front cover (7) and is fixedly connected with the mouth ring (8), and a plurality of static ring teeth (4) are arranged on the inner circumferential surface of the static ring (2) near one side of the impeller front cover (7) in the axial direction; the movable ring (1) is sleeved on the impeller front cover (7) and is fixedly connected with the impeller front cover (7), and a plurality of movable ring teeth (3) staggered with the static ring teeth (4) are arranged on the outer circumferential surface of the movable ring (1) near one side of the mouth ring (8) in the axial direction; the distance between two adjacent groups of static ring teeth (4) is B c , the distance between the inner circumferential surface of the static ring (2) and the outer circumferential surface of the movable ring (1) is H t ; the cross section of the movable ring tooth (3) is in the shape of "dry", comprising a radial ring tooth (33) extending in the radial direction, a first axial ring tooth (31) and a second axial ring tooth (32) perpendicular to the radial ring tooth (33) and parallel to each other; the distance between the first axial ring tooth (31) and the second axial ring tooth (32) is H b , H b =0.05H t ~0.35H t ; the distance between the first axial ring tooth (31) and the outer circumferential surface of the movable ring (1) is H a , H a =0.05H t ~0.35H t ; the tooth thickness of the radial ring tooth (33) in the axial direction is B a , B a =0.1B c ~0.4B c ; the tooth width of the first axial ring tooth (31) and the second axial ring tooth (32) in the radial direction is H v , H v =0.1H t ~0.2H t ; the distance between the first axial ring tooth (31), the second axial ring tooth (32) and the adjacent two sides of the static ring tooth (4) is C s , C s =0.1B c ~0.25B c .

2. The mouth ring seal apparatus of claim 1, wherein, The distance H between the first axial ring tooth (31) and the second axial ring tooth (32) b = 0.05H t ~ 0.2H t The distance H between the first axial ring tooth (31) and the outer circumferential surface of the movable ring (1) a = 0.2H t ~ 0.35H t .

3. The mouth ring seal apparatus of claim 1, wherein, The interval H of the first axial ring tooth (31) and the second axial ring tooth (32) b = 0.15H t ~ 0.2H t The interval H of the first axial ring tooth (31) and the outer circumferential surface of the movable ring (1) a = 0.3H t ~ 0.35H t The tooth thickness B of the radial ring tooth (33) in the axial direction a = 0.3B c ~ 0.4B c The tooth width H of the first axial ring tooth (31) and the second axial ring tooth (32) in the radial direction v = 0.16H t ~ 0.2H t The interval C of the second axial ring tooth (32) and the adjacent two side static ring teeth (4) s = 0.1B c ~ 0.15B c .

4. The mouth ring seal apparatus of claim 1, wherein, The second axial ring tooth (32) is spaced apart from the inner circumferential surface of the static ring (2) by C a , C a ≥ 0.03H t .

5. The mouth ring seal apparatus of claim 1, wherein, A third axial ring tooth (5) is further arranged between the inner circumferential surface of the static ring (2) and the second axial ring tooth (32); that is: The third axial ring tooth (5) is arranged in the middle of the inner circumferential surface of the static ring (2) on the side close to the second axial ring tooth (32). Alternatively, the third axial ring tooth (5) is arranged in the middle of the outer circumferential surface of the second axial ring tooth (32) on the side close to the static ring (2).

6. The mouth ring seal apparatus of claim 5, wherein, The tooth thickness of the third axial ring tooth (5) in the axial direction is B n , B n = B a ; the tooth width of the third axial ring tooth (5) in the radial direction is H n , H n = 0.04H t ~0.1H t , and H n ≤C a .

7. The mouth ring seal apparatus of the centrifugal pump of claim 1, wherein, The distance between the static ring tooth (4) and the outer circumferential surface of the moving ring (1) is C r , C r = 0.05H t ~0.2H t ; the tooth thickness of the static ring tooth (4) in the axial direction is B s , B s = 0.2B c ~0.4B c .

8. The mouth ring seal apparatus of the centrifugal pump of claim 1, wherein, The H t Take 2-5 mm, B c Take 2-5 mm.

9. The mouth ring seal apparatus of the centrifugal pump of claim 1, wherein, The number of the static ring teeth (4) is not less than 3, and the number of the dynamic ring teeth (3) is not less than 2.

10. A centrifugal pump having the mouth ring sealing device according to any one of claims 1-9.

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