Mouth ring sealing device of centrifugal pump and centrifugal pump

Abstract

The invention provides an impeller ring sealing device of a centrifugal pump and the centrifugal pump. The impeller ring sealing device comprises a movable ring and a static ring which are arranged between an impeller ring and an impeller front cover. The distance between every two adjacent sets of static ring teeth is Bc, and the distance between the inner circumferential face of the static ring and the outer circumferential face of the movable ring is Ht. The section of the movable ring tooth is in a dry shape, and the movable ring tooth comprises a radial ring tooth extending in the radial direction, a first axial ring tooth and a second axial ring tooth, wherein the first axial ring tooth and the second axial ring tooth are perpendicular to the radial ring tooth and parallel to each other. The distance Hb between the first axial ring teeth and the second axial ring teeth ranges from 0.05 Ht to 0.35 Ht. The distance Ha between the first axial ring teeth and the outer circumferential face of the movable ring ranges from 0.05 Ht to 0.35 Ht. The tooth thickness Ba of the radial ring teeth in the axial direction ranges from 0.1 Bc to 0.4 Bc. The tooth width Hv of the first axial ring teeth and the second axial ring teeth in the radial direction ranges from 0.1 Ht to 0.2 Ht. The distance Cs between the first axial ring teeth and the static ring teeth on the two adjacent sides and the distance Cs between the second axial ring teeth and the static ring teeth on the two adjacent sides are 0.1 Bc to 0.25 Bc. The eddy-current loss in the sealing cavity is increased by adjusting the tooth structure of the moving ring, so that the leakage amount of fluid at the wear ring under the high-pressure working condition is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of centrifugal pumps, in particular to a centrifugal pump mouth ring sealing device and a centrifugal pump. Background Art

[0002] Centrifugal pumps are a type of fluid delivery equipment widely used in the industrial field. Their working principle mainly relies on the rotation of the impeller to generate centrifugal force, thereby sucking the fluid from the inlet and accelerating it to the outlet. In the structure of a centrifugal pump, the mouth ring is a key sealing component. It is set in the gap between the pump casing and the impeller front cover and is fixedly connected to the pump casing. The main function of the mouth ring is to prevent the 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 a certain amount of movement space for the impeller during thermal expansion or wear. However, in practical applications, especially under high-pressure conditions, the leakage problem at the mouth ring gap becomes particularly prominent. Under high-pressure conditions, the pressure of the fluid on the mouth ring gap increases, resulting in a significant increase in leakage. Leakage will not only reduce the efficiency of the pump and increase energy consumption, but may also 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 conditions has become an important issue in the design and maintenance of centrifugal pumps. Summary of the invention

[0004] In order to solve the problem of increased leakage at the mouth ring of a centrifugal pump under high-pressure conditions, the present invention provides a mouth ring sealing device for a centrifugal pump and a centrifugal pump, which increases the eddy current loss inside the sealing chamber by adjusting the tooth structure of the dynamic ring, thereby greatly reducing the leakage of the fluid at the mouth ring under high-pressure conditions.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A mouth ring sealing device for a centrifugal pump, characterized in that the mouth ring is arranged in the gap between the pump casing and the impeller front cover of the centrifugal pump and is fixedly connected to the pump casing; the mouth ring sealing device includes 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 to the mouth ring, and a plurality of static ring teeth are arranged in the axial direction on the inner circumferential surface of the static ring near the impeller front cover; the dynamic ring is sleeved on the impeller front cover and is fixedly connected to the impeller front cover, and a plurality of dynamic ring teeth are arranged in the axial direction on the outer circumferential surface of the dynamic ring near the mouth ring; the spacing between two adjacent groups of static ring teeth is B c , the distance between the inner circumference of the static ring and the outer circumference of the dynamic ring is H tThe cross section of the movable ring gear is a "stem" type, including radial ring gears extending radially, first axial ring gears perpendicular to the radial ring gears and parallel to each other, and second axial ring gears; the spacing between the first axial ring gear and the second axial ring gear is H b , H b =0.05H t ~0.35H t ; The distance between the first axial ring tooth and the outer circumference of the moving ring is H a , H a =0.05H t ~0.35H t ; The tooth thickness of the radial ring gear in the axial direction is B a , B a =0.1B c ~0.4B c The tooth widths of the first axial ring gear and the second axial ring gear in the radial direction are both H v , H v =0.1H t ~0.2H t The spacing between the first axial ring gear, the second axial ring gear and the adjacent two stationary ring gears is C s , C s =0.1B c ~0.25B c .

[0007] Furthermore, the distance H between the first axial ring gear and the second axial ring gear is b =0.05H t ~0.2H t ; The distance H between the first axial ring tooth and the outer circumference of the moving ring a =0.2H t ~0.35H t .

[0008] Furthermore, the distance H between the first axial ring gear and the second axial ring gear is b =0.15H t ~0.2H t , the distance H between the first axial ring tooth and the outer circumference of the moving ring a =0.3H t ~0.35H t , the tooth thickness B of the radial ring gear in the axial direction a =0.3B c ~0.4B c , the tooth width H of the first axial ring gear and the second axial ring gear in the radial direction v =0.16H t ~0.2H t , the distance C between the second axial ring gear and the adjacent two stationary ring gears s=0.1B c ~0.15B c .

[0009] Furthermore, the distance between the second axial ring gear and the inner circumferential surface of the stationary ring is C a , C a ≥0.03H t .

[0010] Furthermore, a third axial ring tooth is provided between the inner circumferential surface of the stationary ring and the second axial ring tooth; that is:

[0011] The third axial ring gear is arranged at the middle of the inner circumferential surface of the stationary ring close to the second axial ring gear;

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

[0013] Furthermore, 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] Furthermore, the distance between the stationary ring teeth 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 stationary ring teeth in the axial direction is B s , B s =0.2B c ~0.4B c .

[0015] Furthermore, the H t Take 2~5mm, B c Take 2 to 5 mm.

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

[0017] A centrifugal pump having a mouth ring sealing device as described in any one of the above items.

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

[0019] 1. The "dry" type dynamic ring teeth in the present invention subdivide the original 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 vortices, the pressure energy of the high-pressure fluid can be more effectively converted into thermal energy, and then the energy of the fluid can be reduced by heat dissipation, thereby achieving the effect of reducing leakage. This means that even under high-pressure working conditions, the mouth ring sealing device can maintain a low leakage level and exhibit excellent sealing performance. This improvement has important practical significance for improving the working efficiency of centrifugal pumps, extending the service life of equipment, and ensuring operational safety, and therefore has a very broad market application prospect.

[0020] 2. The present invention further studies various structural parameters (H a , H b , B a , H v , C s ) on the leakage, and systematic optimization was performed. The optimized mouth ring sealing device not only reduces the gap, increases entropy increase, and increases energy dissipation, thereby significantly enhancing the leakage blocking effect, but also reduces the average velocity of the fluid in the chamber by reducing the gap, weakens the inertia effect, and further reduces the leakage of high-pressure fluid. In addition, the optimized design also cleverly balances the gap size, avoiding component collisions caused by too small a gap, and manufacturing difficulties caused by too high machining precision requirements.

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

[0022] Figure 1 This is a schematic structural diagram of a centrifugal pump with a mouth ring sealing device as described in Example 1.

[0023] Figure 2 This is a schematic structural diagram of the mouth ring sealing device of the centrifugal pump described in Example 1.

[0024] Figure 3 This is a schematic structural diagram of the mouth ring sealing device of the centrifugal pump described in Example 2.

[0025] Figure 4 This is a schematic structural diagram of the mouth ring sealing device of the centrifugal pump described in Example 3.

[0026] Figure 5 This is a schematic structural diagram of the mouth ring sealing device of the centrifugal pump described in Example 4.

[0027] Figure 6 This is a schematic structural diagram of the mouth ring sealing device of the centrifugal pump described in Example 5.

[0028] Figure 7 This is a schematic structural diagram of the mouth ring sealing device of the centrifugal pump described in Example 6.

[0029] Figure 8 This is a schematic diagram of the structure of the mouth ring sealing device of the centrifugal pump described in comparative experiment 1.

[0030] Fig. 9 This is a schematic diagram of the structure of the mouth ring sealing device of the centrifugal pump described in comparative experiment 2.

[0031] Fig.10 This is a schematic diagram of the structure of the mouth ring sealing device of the centrifugal pump described in comparative experiment 3.

[0032] Fig.11 This is a schematic diagram of the structure of the mouth ring sealing device of the centrifugal pump described in comparative experiment 4.

[0033] Fig.12 It is a comparison chart of leakage simulation of 10 kinds of mouth ring sealing devices in Examples 1 to 6 and Comparative Experiments 1 to 4.

[0034] The reference numerals are as follows:

[0035] 1-dynamic ring; 2-stationary ring; 3-dynamic ring teeth; 31-first axial ring teeth; 32-second axial ring teeth; 33-radial ring teeth; 4-stationary ring teeth; 5-third axial ring teeth; 6-pump casing; 7-impeller front cover; 8-mouth ring. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0037] Example 1

[0038] The mouth ring sealing device of the centrifugal pump in this embodiment comprises a dynamic ring 1 and a static ring 2 arranged between the mouth ring 8 of the centrifugal pump and the impeller front cover 7. The mouth ring 8 is arranged in the gap between the pump casing 6 of the centrifugal pump and the impeller front cover 7 and is fixedly connected to the pump casing 6. Figure 1 This is a schematic structural diagram of a centrifugal pump with a mouth ring sealing device described in this embodiment.

[0039] The stationary ring 2 is sleeved on the impeller front cover 7 and fixedly connected to the mouth ring 8. A plurality of stationary ring teeth 4 are arranged along the axial direction on the inner circumference of the stationary ring 2 near the impeller front cover 7. The moving ring 1 is sleeved on the impeller front cover 7 and fixedly connected to the impeller front cover 7. A plurality of moving ring teeth 3 interlaced with the stationary ring teeth 4 are arranged along the axial direction on the outer circumference of the moving ring 1 near the mouth ring 8. The spacing between two adjacent groups of stationary ring teeth 4 is B. c , the distance between the inner circumference of the static ring 2 and the outer circumference of the dynamic ring 1 is H t In this embodiment, H t Take 3mm, B c Take 3mm. Figure 2 This is a mouth ring sealing device suitable for a centrifugal pump as described in this embodiment.

[0040] The cross section of the moving ring teeth 3 is a "trunk" type, including radial ring teeth 33 extending in the radial direction, first axial ring teeth 31 and second axial ring teeth 32 perpendicular to the radial ring teeth 33 and parallel to each other. The number of the stationary ring teeth is N1, the number of the moving ring teeth is N2, and the distance between the stationary ring teeth and the outer circumference of the moving ring is C r , the tooth thickness of the stationary ring teeth in the axial direction is B s , the distance between the first axial ring gear 31 and the second axial ring gear 32 is H b, , the distance between the first axial ring gear 31 and the outer circumferential surface of the rotating ring 1 is H a , the tooth thickness of the radial ring tooth 33 in the axial direction is B a The tooth widths of the first axial ring gear 31 and the second axial ring gear 32 in the radial direction are both H v The distance between the first axial ring gear 31, the second axial ring gear 32 and the adjacent stationary ring gears 4 on both sides is C s The distance between the second axial ring gear 32 and the inner circumference of the stationary ring 2 is C a The mouth ring sealing device described in this embodiment is recorded as a type A mouth ring sealing device, and the specific values ​​are shown in the following Table 1.

[0041] Table 1 Structural parameters of type A mouth ring seal device

[0042]

[0043] Furthermore, this embodiment also includes a centrifugal pump equipped with the above-mentioned mouth ring sealing device.

[0044] Example 2

[0045] The difference between the mouth ring sealing device for centrifugal pumps described in this embodiment and the embodiment 1 is that the distance H between the first axial ring gear 31 and the outer circumferential surface of the dynamic ring 1 is a =0.17H t , the distance H between the first axial ring gear 31 and the second axial ring gear 32 b=0.33H t , the rest of the structures and parameters remain unchanged. Figure 3 The structure diagram of the mouth ring sealing device suitable for a centrifugal pump described in this embodiment is shown in FIG. The mouth ring sealing device described in this embodiment is recorded as a B-type mouth ring sealing device.

[0046] Example 3

[0047] The difference between the mouth ring sealing device for centrifugal pumps described in this embodiment and the embodiment 1 is that a third axial ring tooth 5 is further provided between the inner circumferential surface of the stationary ring 2 and the second axial ring tooth 32, and the third axial ring tooth 5 is provided in the middle of the outer circumferential surface of the second axial ring tooth 32 close to the stationary ring 2, 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 gear 5 in the radial direction is H n , H n =0.07H t , the rest of the structures and parameters remain unchanged. Figure 4 Schematic diagram of the structure of the mouth ring sealing device suitable for a centrifugal pump described in this embodiment, and the mouth ring sealing device described in this embodiment is recorded as an A-down point type mouth ring sealing device.

[0048] Example 4

[0049] The difference between the mouth ring sealing device for centrifugal pumps described in this embodiment and the embodiment 1 is that a third axial ring tooth 5 is further provided between the inner circumferential surface of the stationary ring 2 and the second axial ring tooth 32, and the third axial ring tooth 5 is provided in the middle of the inner circumferential surface of the stationary ring 2 close to 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 gear 5 in the radial direction is H n , H n =0.07H t , the rest of the structures and parameters remain unchanged. Figure 5 Schematic diagram of the structure of the mouth ring sealing device suitable for a centrifugal pump described in this embodiment, and the mouth ring sealing device described in this embodiment is recorded as an A-upper point type mouth ring sealing device.

[0050] Example 5

[0051] The difference between the mouth ring sealing device for centrifugal pumps described in this embodiment and the embodiment 2 is that a third axial ring tooth 5 is further provided between the inner circumferential surface of the stationary ring 2 and the second axial ring tooth 32, and the third axial ring tooth 5 is provided in the middle of the outer circumferential surface of the second axial ring tooth 32 close to the stationary ring 2, and 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 gear 5 in the radial direction is H n , H n =0.07H t , the rest of the structures and parameters remain unchanged. Figure 6 Schematic diagram of the structure of the mouth ring sealing device suitable for a centrifugal pump described in this embodiment, and the mouth ring sealing device described in this embodiment is recorded as a B-down point type mouth ring sealing device.

[0052] Example 6

[0053] The difference between the mouth ring sealing device for centrifugal pumps described in this embodiment and the embodiment 2 is that a third axial ring tooth 5 is further provided between the inner circumferential surface of the stationary ring 2 and the second axial ring tooth 32, and the third axial ring tooth 5 is provided in the middle of the inner circumferential surface of the stationary ring 2 close to 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 gear 5 in the radial direction is H n , H n =0.07H t , the rest of the structures and parameters remain unchanged. Figure 7 Schematic diagram of the structure of the mouth ring sealing device suitable for a centrifugal pump described in this embodiment, and the mouth ring sealing device described in this embodiment is recorded as a B-down point type mouth ring sealing device.

[0054] In order to verify that the mouth ring sealing device suitable for a centrifugal pump described in the present invention has better sealing performance, the present invention also designed the following four groups of comparative experiments.

[0055] Comparative experiment 1

[0056] The difference between the mouth ring sealing device in this comparative experiment and that in Example 1 is that the dynamic ring teeth are eliminated, and the other structures and parameters remain unchanged. Figure 8 This is a structural schematic diagram of a mouth ring sealing device suitable for a centrifugal pump described in this comparative experiment. The mouth ring sealing device described in this comparative experiment is recorded as a straight-through type mouth ring sealing device.

[0057] Comparative experiment 2

[0058] The difference between the mouth ring sealing device in this comparative experiment and Example 1 is that the dynamic ring teeth in this comparative experiment are radial ring teeth, and the tooth thickness B of the radial ring teeth in the axial direction is r =0.33B c , the distance C between the radial ring gear and the adjacent stationary ring gears on both sides s =0.1B c , the tooth width H of the radial ring gear in the radial directionr =0.33H t , the rest of the structures and parameters remain unchanged. Fig. 9 This is a structural schematic diagram of a mouth ring sealing device suitable for a centrifugal pump described in this comparative experiment. The mouth ring sealing device described in this comparative experiment is recorded as a staggered mouth ring sealing device.

[0059] Comparative experiment 3

[0060] The difference between the mouth ring sealing device in this comparative experiment and Example 1 is that the cross section of the dynamic ring teeth in this comparative experiment is T-shaped, including radial ring teeth extending in the radial direction and axial ring teeth perpendicular to the radial ring teeth. The distance H between the axial ring teeth and the outer circumference of the dynamic ring is a =0.33H t , the tooth thickness B of the radial ring gear in the axial direction a =0.33B c , the tooth width H of the axial ring gear in the radial direction v =0.17H t , the distance C between the axial ring gear and the adjacent stationary ring gears on both sides s =0.1B c , the rest of the structures and parameters remain unchanged. Fig.10 This is a structural schematic diagram of a mouth ring sealing device suitable for a centrifugal pump described in this comparative experiment. The mouth ring sealing device described in this comparative experiment is recorded as a large T-shaped mouth ring sealing device.

[0061] Comparative experiment 4

[0062] The difference between the mouth ring sealing device in this comparative experiment and Example 1 is that the cross section of the dynamic ring teeth in this comparative experiment is T-shaped, including radial ring teeth extending in the radial direction and axial ring teeth perpendicular to the radial ring teeth. The distance H between the axial ring teeth and the outer circumference of the dynamic ring is a =0.17H t , the tooth thickness B of the radial ring gear in the axial direction a =0.33B c , the tooth width H of the axial ring gear in the radial direction v =0.17H t , the distance C between the axial ring gear and the adjacent stationary ring gears on both sides s =0.1B c , the rest of the structures and parameters remain unchanged. Fig.11 This is a structural schematic diagram of a mouth ring sealing device suitable for a centrifugal pump described in this comparative experiment. The mouth ring sealing device described in this comparative experiment is recorded as a small T-type mouth ring sealing device.

[0063] The present invention uses CFD related simulation software to simulate and calculate the leakage (in kg·s) of 10 kinds of mouth ring sealing devices in Examples 1 to 6 and Comparative Experiments 1 to 4 under different inlet and outlet pressure differences, and compares their performance. Fig.12 The leakage simulation comparison diagram of 10 kinds of mouth ring sealing devices in Examples 1 to 6 and Comparative Experiments 1 to 4. Fig.12 From the simulation results, it can be clearly observed that the leakage of the mouth ring sealing devices in Examples 1 to 6 under various pressure difference conditions is always lower than that of the mouth ring sealing devices in Comparative Experiments 1 to 4, among which the B-type mouth ring sealing device has the best sealing performance. Table 2 Fig.12 Specific leakage comparison table of simulation results shown.

[0064] Table 2 Leakage comparison table

[0065]

[0066] It can be seen from Table 6 that, compared with the straight-through mouth ring sealing device in Comparative Experiment 1, the leakage of the mouth ring sealing device for centrifugal pumps according to the present invention can be reduced by up to 63.7%. Compared with the staggered mouth ring sealing device in Comparative Experiment 2, the leakage of the mouth ring sealing device for centrifugal pumps according to the present invention can be reduced by up to 22.6%. Compared with the large T-shaped mouth ring sealing device in Comparative Experiment 3, the leakage of the mouth ring sealing device for centrifugal pumps according to the present invention can be reduced by up to 17.4%. Compared with the small T-shaped mouth ring sealing device in Comparative Experiment 4, the leakage of the mouth ring sealing device for centrifugal pumps according to the present invention can be reduced by up to 18%. At the same time, among the six types of oral ring sealing devices in Examples 1 to 6, the sealing performance of the oral 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 oral ring sealing device without the third axial ring tooth 5 (Type A, Type B), and among them, the leakage is the lowest when the third axial ring tooth 5 is located in the middle of the inner circumferential surface of the stationary ring 2 close to the side of the second axial ring tooth 32 (B upper point type).

[0067] In order to further study the various structural parameters (H a , H b , B a , H v , C s ) on the leakage, this embodiment conducted a five-factor four-level orthogonal test on the A-type mouth ring sealing device in Example 1, where each factor accounts for the axial length B of the sealing cavity surrounded by two adjacent groups of stationary ring teeth 4. c Or radial height H t The ratio of and the simulation results under high pressure conditions are shown in Table 3 below.

[0068] Table 3 Simulation results

[0069]

[0070]

[0071] As can be seen from the table above, the influence of the above five parameters on the leakage of high-pressure fluid is nonlinear. Through the comparison of the range, it is found that C S The most significant effect on the leakage is the combination of parameters shown in 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 , H b =0.2H t ) has the best throttling efficiency under high-pressure conditions. Compared with other parameter combinations, the leakage is reduced by up to 46.6%. It can be seen that the present invention has made further improvements to the above parameters on the basis of the "dry" type dynamic ring gear 3 mechanism, so that the mouth ring sealing device exhibits more excellent sealing performance under high-pressure conditions, further achieving the goal of low leakage.

[0072] The embodiments are preferred implementations of the present invention, but the present invention is not limited to the above-mentioned implementations. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essential content of the present invention belong to the protection scope of the present invention.

Claims

1. A centrifugal pump mouth ring sealing device, characterized in that: The mouth ring (8) is arranged at the gap between the pump casing (6) and the impeller front cover (7) of the centrifugal pump and is fixedly connected to the pump casing (6); the mouth ring sealing device comprises a dynamic 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 to the mouth ring (8); a plurality of static ring teeth (4) are arranged along the axial direction on the inner circumferential surface of the static ring (2) close to the impeller front cover (7); the dynamic ring (1) is sleeved on the impeller front cover (7) and is fixedly connected to the impeller front cover (7); a plurality of dynamic ring teeth (3) are arranged along the axial direction on the outer circumferential surface of the dynamic ring (1) close to the mouth ring (8) and are staggered and interlaced with the static ring teeth (4); the spacing between two adjacent groups of static ring teeth (4) is B c , the distance between the inner circumference of the stationary ring (2) and the outer circumference of the dynamic ring (1) is H t The cross section of the movable ring tooth (3) is of a "trunk" type, comprising a radial ring tooth (33) extending in the radial direction, a first axial ring tooth (31) perpendicular to the radial ring tooth (33) and parallel to each other, and a second axial ring tooth (32); the spacing 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 gear (31) and the outer circumferential surface of the moving ring (1) is H a , H a =0.05H t ~0.35H t The tooth thickness of the radial ring gear (33) in the axial direction is B a , B a =0.1B c ~0.4B c The tooth widths of the first axial ring teeth (31) and the second axial ring teeth (32) in the radial direction are both H v , H v =0.1H t ~0.2H t The spacing between the first axial ring gear (31), the second axial ring gear (32) and the adjacent two side stationary ring gears (4) is C s , C s =0.1B c ~0.25B c .

2. The centrifugal pump mouth ring sealing device according to claim 1, characterized in that: The distance H between the first axial ring gear (31) and the second axial ring gear (32) is b =0.05H t ~0.2H t ; The distance H between the first axial ring tooth (31) and the outer circumferential surface of the moving ring (1) a =0.2H t ~0.35H t .

3. The centrifugal pump mouth ring sealing device according to claim 1, characterized in that: The distance H between the first axial ring gear (31) and the second axial ring gear (32) is b =0.15H t ~0.2H t , the distance H between the first axial ring tooth (31) and the outer circumferential surface of the moving ring (1) a =0.3H t ~0.35H t , the tooth thickness B of the radial ring gear (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 is v =0.16H t ~0.2H t , the distance C between the second axial ring gear (32) and the adjacent stationary ring gears (4) on both sides s =0.1B c ~0.15B c .

4. The centrifugal pump mouth ring sealing device according to claim 1, characterized in that: The distance between the second axial ring gear (32) and the inner circumferential surface of the stationary ring (2) is C a , C a ≥0.03H t .

5. The centrifugal pump mouth ring sealing device according to claim 1, characterized in that: A third axial ring tooth (5) is also provided between the inner circumferential surface of the stationary ring (2) and the second axial ring tooth (32); that is: The third axial ring gear (5) is arranged at the middle of the inner circumferential surface of the stationary ring (2) on a side close to the second axial ring gear (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) close to the stationary ring (2).

6. The centrifugal pump mouth ring sealing device according to claim 5, characterized in that: 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 centrifugal pump mouth ring sealing device according to claim 1, characterized in that: The distance between the stationary ring teeth (4) and the outer circumferential surface of the dynamic ring (1) is C r , C r =0.05H t ~0.2H t ; The tooth thickness of the stationary ring tooth (4) in the axial direction is B s , B s =0.2B c ~0.4B c .

8. The mouth ring sealing device of a centrifugal pump according to claim 1, characterized in that: The H t Take 2~5mm, B c Take 2 to 5 mm.

9. The centrifugal pump mouth ring sealing device according to claim 1, characterized in that: The number of the stationary 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 comprising the port ring seal device according to any one of claims 1 to 9.

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