Corrosion resistant, dry running shaft seal

Abstract

The application discloses a kind of anticorrosive dry grinding shaft seals, shaft seal is installed on the main shaft of centrifugal pump, shaft seal includes seal box assembly, mechanical seal, mechanical seal includes static ring, dynamic ring, it is characterized in that seal box assembly is fixed with pump shell, dynamic ring is fixed on the main shaft, dynamic ring is located in pump cavity and contacts with conveying liquid, seal box assembly includes seal box, the seal box post-cover of separate or integral setting with seal box, the static ring push elastic ring in seal box, static ring push elastic ring both ends are compressed between seal box post-cover, static ring, static ring push elastic ring is in elastic compression state, make static ring friction width and dynamic ring friction width contact seal, rigid baffle is consolidated on the sealing end surface of seal box and pump shell, rigid baffle inner hole circumferential surface and static ring outer circumferential surface contact seal, static ring push elastic ring outer circumferential surface, seal box post-cover, rigid baffle and static ring are enclosed to store liquid cavity.

Description

Technical Field

[0001] This invention relates to the field of centrifugal pump shaft seals, and more particularly to centrifugal pump shaft seals for conveying corrosive slurries containing chloride ions or other corrosive components. Background Technology

[0002] Centrifugal pumps are used in flue gas desulfurization processes in steel and coal chemical plants, as well as in nickel-cobalt hydrometallurgical processes, to transport clear liquids or slurries containing chloride ions. These media are highly corrosive to metals, especially pump shaft seals, which require metal components such as springs, bolts, and nuts. These components are easily corroded by the chloride-containing liquids or corrosive gases being transported. Therefore, the development of metal-free pump shaft seals has been proposed.

[0003] Some people use a dynamic seal composed of a lip rubber seal, a ceramic bushing, and a fiberglass sealing box to transport this type of medium. This is because the components of this seal combination are all made of non-metallic materials, and the seal can withstand the corrosion of the chloride-containing medium being transported. However, the downside is that this type of shaft seal is prone to wear and leakage, resulting in material leakage and environmental problems.

[0004] To address the above shortcomings, the inventors disclosed a mechanical seal (such as a drive ring 1, a stationary ring 2, a rubber push ring 3, and a sealing box 4) in patent 91213550.6. Figure 1 The advantage of this type of mechanical seal is that none of the sealing components are made of metal, especially the push spring of the stationary ring, which is also made of metal, but only uses a rubber elastic ring to push the stationary ring of the mechanical seal. This type of pump shaft seal has excellent corrosion resistance, and all mechanical seal components will not be corroded by the conveyed medium. However, it has the following disadvantages: First, the conveyed medium in the pump chamber comes into contact with the rubber push ring, and the rubber push ring is immersed in the conveyed medium. The acidity or alkalinity in the conveyed medium will cause a reduction reaction of the vulcanizing agent in the rubber push ring, making the rubber push ring soft and lose its elasticity, thus causing the seal to fail. Secondly, the outer circumference of the rubber elastic ring of the push-stationary ring is connected to the fluid inside the pump chamber. Therefore, pressure changes in the fluid inside the pump chamber act on the outer spherical surface of the rubber ring. When the fluid is under negative pressure, the rubber ball expands radially and contracts axially, reducing the specific pressure between the dynamic and stationary rings, thus causing leakage. Conversely, when the fluid pressure inside the pump chamber is high, the fluid pressure also acts on the outer spherical surface of the rubber elastic ring, causing the rubber ring to contract radially and elongate axially, thereby pushing the stationary ring and increasing the specific pressure on the working surfaces of the dynamic and stationary rings, accelerating the friction and wear of the dynamic and stationary rings. Thirdly, because this mechanical seal cannot be connected to external cooling water, it will burn out due to dry running if the pump operates without fluid.

[0005] Therefore, this metal-free mechanical seal still needs improvement. To address the seal's weakness in resisting dry friction, the inventors disclosed a metal-free mechanical seal with cooling water flushing in patent 201420286999.6 (e.g., Figure 2The original technology involves opening a liquid filling hole 4.1 on the sealing box 4, opening a liquid passage hole 3.1 on the spherical rubber ring, setting a flexible partition between the sealing box cavity and the pump cavity, and setting a dynamic shaft seal 5 on the main shaft to prevent cooling water leakage. Through innovative improvements, the rubber push ring in the original technology no longer comes into contact with the pumped liquid, and the push ring will not be deformed by the acid and alkali media in the pump cavity. Moreover, the seal can also be operated without a circuit and has good anti-dry friction performance. However, the following shortcomings still exist: First, because the cavity between the pump cavity and the sealing box uses a flexible partition with a "U"-shaped ring groove, the flexible partition will tighten, compress, or push apart the specific pressure between the dynamic and static rings due to the pressure change of the fluid in the pump cavity. That is, when the fluid pressure in the pump cavity is high, the flexible partition is pushed to the outside of the pump cavity by the fluid pressure, which causes the dynamic and static rings of the mechanical seal to separate, resulting in the pumped liquid in the pump cavity leaking into the cooling water cavity, causing the pump seal to fail. Secondly, the lifespan of the shaft seal 5, which seals the cooling water, is short, generally only 3 to 4 months, and there is still a risk of cooling water leakage. Thirdly, it consumes 2 to 3 tons of cooling water per day, which is considerable.

[0006] Therefore, the existing metal-free mechanical seals with good corrosion resistance still have shortcomings such as unstable performance and cooling water leakage, and there is still a need for improvement. Summary of the Invention

[0007] To address the aforementioned shortcomings, this invention provides a mechanical seal with a driving ring and a stationary ring. This mechanical seal has no metal components, exhibits good chloride ion resistance, and can withstand dry running without damage. It can also transport solid slurry. The mechanical seal has good stability, simple structure, and high safety. Compared with conventional mechanical seals, it saves approximately 98% of cooling water and is a corrosion-resistant and dry-run-resistant shaft seal.

[0008] To achieve the objective of this invention, the following technical solution is provided: a corrosion-resistant and dry-friction-resistant shaft seal, the shaft seal being installed on the main shaft of a centrifugal pump, the shaft seal including a sealing box assembly and a mechanical seal, the mechanical seal including a stationary ring and a rotating ring, characterized in that the sealing box assembly is fixedly connected to the pump casing, the rotating ring is fixed on the main shaft, the rotating ring is located inside the pump cavity and in contact with the conveyed liquid, the sealing box assembly including a sealing box, a sealing box pressure cover separately or integrally set with the sealing box, and a stationary ring push elastic ring placed inside the sealing box, the two ends of the stationary ring push elastic ring being compressed between the sealing box pressure cover and the stationary ring, the stationary ring push elastic ring being in an elastically compressed state, so that the friction amplitude of the stationary ring and the friction amplitude of the rotating ring are in contact and sealed, a rigid partition plate is fixed on the sealing end face of the sealing box and the pump casing, the inner hole circumferential surface of the rigid partition plate is in contact and sealed with the outer circumferential surface of the stationary ring, the outer circumferential surface of the stationary ring push elastic ring, the sealing box pressure cover, the rigid partition plate and the stationary ring together form a liquid storage cavity.

[0009] Preferably, the inner circumferential surface of the rigid partition is provided with at least one annular groove, and an O-ring or lip seal is provided in the annular groove.

[0010] Preferably, the stationary ring friction amplitude is set to at least two with flush end faces, and a liquid storage ring groove is formed between two adjacent friction amplitudes. A liquid passage hole is opened in the stationary ring, with one end of the liquid passage hole connected to the liquid storage ring groove and the other end connected to the liquid storage cavity.

[0011] Preferably, the sealed box has a liquid inlet hole that connects to the liquid storage chamber, and the liquid inlet hole is connected to an external liquid source.

[0012] Preferably, the sealing box back cover is provided with a concave-convex ring with an embedded stationary ring pushing elastic ring. The convex part of the concave-convex ring is embedded in the sealing box back cover, and the concave part is matched with one end of the stationary ring pushing elastic ring.

[0013] Preferably, the stationary ring pusher elastic ring is drum-shaped or corrugated cylindrical.

[0014] Preferably, when the stationary ring pusher elastic ring is drum-shaped, a spring is provided on the inner side.

[0015] As a preferred embodiment, when the stationary ring pusher elastic ring is a corrugated straight cylindrical shape, a rigid anti-compression ring is provided on the inner side.

[0016] Preferably, a spring is provided on the inner side of the corrugated stationary ring push ring.

[0017] As a preferred option, the sealed box is also provided with a slag discharge hole.

[0018] Preferably, the stationary ring pushes the elastic ring and has mutually coupled concave and convex portions between the stationary ring and / or the sealing box.

[0019] Preferably, a bushing is provided on the main shaft, and the rotating ring is fixed between the bushing and the impeller.

[0020] Preferably, a bushing is provided on the main shaft, and an outward-folding receiving cavity for fixing the moving ring is provided at the end of the bushing near the impeller. The moving ring is fixed in the outward-folding receiving cavity. The bushing is provided with anti-rotation and anti-pull-out holes and grooves on the front side of the sealing box back cover. A positioning piece is provided in the groove, and a positioning screw fixes the positioning piece to the sealing box back cover. A fastening screw is provided in the hole to fix the bushing on the main shaft.

[0021] Preferably, the bushing is composed of metal and non-metal parts, with the outward-turning receiving cavity of the fixed rotating ring located on the non-metal part, and the anti-rotation and anti-pull-out holes and grooves located on the metal part.

[0022] Preferably, the outward-facing receiving cavity is provided with a concave-convex portion that couples with the moving ring.

[0023] Preferably, a sealing element is provided between the outer peripheral surface of the moving ring and the inner wall of the outward-facing receiving cavity.

[0024] Preferably, an adjusting sleeve is provided between the bushing and the impeller, and an O-ring is provided on the contact surface between the adjusting sleeve and the bushing.

[0025] As a preferred option, the two friction pairs on the stationary ring are configured with one hard and one soft material, with the outer friction pair made of hard material and the inner friction pair made of soft material.

[0026] Preferably, a bushing is provided on the main shaft, and the rotating ring adopts an L-shaped base. The L-shaped base is riveted to the bushing and a sealing element is provided on the contact surface. The bushing and the L-shaped base are provided with mutually coupled anti-rotation convex and concave parts.

[0027] Preferably, a bushing is provided on the main shaft, the connection between the rotating ring and the bushing adopts a hook structure and is provided with mutually coupled anti-rotation protrusions and recesses, and a seal is provided between the contact surfaces of the rotating ring and the bushing.

[0028] Preferably, the sealed box has a liquid outlet hole, one end of which is connected to the liquid storage chamber and the other end is connected to an external liquid source. The liquid outlet hole, the liquid inlet hole, the liquid storage chamber and the external liquid source form a cooling cycle.

[0029] Beneficial effects of this invention:

[0030] 1. This sealing structure is extremely simple and its working principle is scientific. It not only saves manufacturing costs by 30% compared to similar products, but also facilitates maintenance and installation.

[0031] 2. This technology can achieve the function of lubrication and sealing with a small amount of cooling water, so that the mechanical seal will not burn out when the pump is running without liquid. As a result, the pump has the ability to resist dry running and dry friction. Moreover, it saves 3 to 5 tons of cooling water per day compared with conventional mechanical seals. The mechanical seal of this technology consumes 3 to 5 kg of cooling water in 24 hours, which has a very good water-saving effect.

[0032] 3. Because the flow parts of this machine seal are all made of non-metallic materials, and the pushing part of the pushing stationary ring is made of rubber, without the use of metal springs, it is not afraid of corrosion from corrosive liquids and gases. Therefore, this seal has excellent corrosion resistance.

[0033] 4. Both the dynamic and static rings of the mechanical seal are made of silicon carbide material with excellent wear resistance and corrosion resistance. Therefore, it is suitable not only for pumps that transport slurries, but also for pumps that transport clear liquids, making it extremely versatile.

[0034] 5. This mechanical seal overcomes the problem in the original technology where the pressure of the pump chamber liquid acts on the stationary ring of the mechanical seal, pushing the drum ring, which makes the specific pressure of the working surfaces of the dynamic and stationary rings of the mechanical seal unstable, and thus makes the performance of the mechanical seal unstable. Therefore, through improvement, the stability and reliability of the pump mechanical seal are enhanced, thereby improving safety.

[0035] 6. Because this machine seal has excellent water-saving function, there is no need to spend money to treat the cooling water that causes secondary pollution. At the same time, it makes the working environment of the pump very clean. Therefore, this seal has good water-saving, cost-saving and environmental protection functions. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the original mechanical seal structure without water cooling.

[0037] Figure 2 This is a schematic diagram of the original water-cooled mechanical seal structure.

[0038] Figure 3 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0039] Figure 4 for Figure 3 A magnified view of a portion of the image;

[0040] Figure 5 This is a schematic diagram of the structure of Example 2;

[0041] Figure 6 This is a schematic diagram of the structure of Example 3;

[0042] Figure 7 This is a schematic diagram of the structure of Example 4;

[0043] Figure 8 This is a schematic diagram of the structure of Example 5;

[0044] Figure 9 This is a schematic diagram of the structure of Example 6;

[0045] Figure 10 This is a schematic diagram of the structure of Example 7;

[0046] Figure 11 This is a schematic diagram of the structure of Example 8;

[0047] Figure 12 This is a schematic diagram of the structure of Example 9;

[0048] Figure 13 This is a schematic diagram of the structure of Example 10;

[0049] Figure 14 This is a schematic diagram of the structure of Example 11;

[0050] Figure 15 This is a schematic diagram of the structure of Example 12. Detailed Implementation

[0051] The technical solutions in the embodiments of the present invention will now be clearly and completely described in conjunction with the accompanying drawings.

[0052] Example 1: As Figure 3 , 4As shown, a corrosion-resistant and dry-wear-resistant centrifugal pump has a shaft seal mounted on the main shaft 6 of the centrifugal pump, and an impeller 7 mounted on the main shaft 6. The shaft seal includes a sealing box assembly and a mechanical seal. The mechanical seal includes a stationary ring 2 and a rotating ring 1. The sealing box assembly is fixedly connected to the pump casing 4. A shaft sleeve 3 is sleeved on the main shaft 6. The rotating ring 1 is fixed between the shaft sleeve 3 and the impeller 7 and is located in the pump cavity, in contact with the conveyed liquid. The sealing box assembly includes a sealing box 9, a sealing box cover 10 separately connected to the sealing box 9, and a stationary ring push elastic ring 8 placed inside the sealing box 9. The sealing box cover 10 has a concave-convex ring 1 embedded with the stationary ring push elastic ring 8. 0.1, the protruding part of the concave-convex ring 10.1 is embedded in the sealing box back cover 10, and the concave part is matched with one end of the stationary ring push elastic ring 8. The other end of the stationary ring push elastic ring 8 is compressed on the stationary ring 2. The stationary ring push elastic ring 8 is in an elastic compression state, so that the friction amplitude of the stationary ring 2 contacts and seals with the friction amplitude of the moving ring 1. A rigid partition 11 is fixed on the sealing end face of the sealing box 9 and the pump housing 4. An annular groove is provided on the outer peripheral surface of the rigid partition 11. An O-ring seal 12 is provided in the annular groove. The outer peripheral surface of the stationary ring push elastic ring 8, the sealing box back cover 10, the rigid partition 11 and the stationary ring 2 together form a liquid storage cavity 18. The stationary ring 2 has two friction surfaces with flush end faces, forming a liquid storage ring groove 2.2 between them. Three liquid passage holes 2.4 are provided inside the stationary ring. The purpose of these three holes is to prevent material leakage into the liquid storage ring groove 2.2 and blockage of the holes during pump pulse vibration. As the number of holes increases, even if a small number of holes become blocked, it will not affect the normal operation of the mechanical seal. The diameter of each hole is 1-3 mm. One end of each liquid passage hole 2.4 connects to the liquid storage ring groove 2.2, and the other end connects to the liquid storage cavity 18. The sealing box 9 has an inlet hole that connects to the liquid storage cavity 18 and is connected to an external liquid source 13. The sealing box 9 also has a slag discharge hole 17. The stationary ring push elastic ring 8 is drum-shaped and has anti-rotation concave-convex wedging 10.1. The concave-convex wedging 10.1 is coupled and matched with the concave-convex parts 8.1 and 2.5 on the stationary ring 2.

[0053] Example 2: As Figure 5 As shown, referring to Embodiment 1, with the other features unchanged, the stationary ring pushing elastic ring 8 is a corrugated straight cylinder, and a rigid anti-compression ring 20 is provided on the inner side.

[0054] Example 3: As Figure 6 As shown, referring to Embodiment 1, with the other features unchanged, the outer peripheral surface of the rigid partition 58 is provided with two annular grooves, and an O-ring and a lip seal are provided in the annular grooves.

[0055] Example 4: Figure 7 As shown, referring to Embodiment 1, with the other features unchanged, a spring 24 is provided on the inner side of the corrugated stationary ring push ring.

[0056] Example 5: Figure 8As shown, referring to Example 3, the other features remain unchanged. The two friction pairs on the stationary ring are set with one hard and one soft. That is, the outer friction pair 2.1.1 is in contact with the slurry and is made of hard material, while the inner friction pair 2.1.2 is only in contact with the lubricant and is made of soft material with low heat value.

[0057] Example 6: As Figure 9 As shown, referring to Embodiment 1, with the remaining features unchanged, the bushing 3 near the impeller 7 end has an outward-folding receiving cavity 3.1 for fixing the moving ring 1. The moving ring 1 is fixed inside the outward-folding receiving cavity 3.1. The bushing 3, located on the front side of the sealing box back cover 10, has a hole 3.3.1 and a groove 3.3.2 for anti-rotation and anti-pull-out. A positioning piece 21 is provided in the groove 3.3.2, and a positioning screw 22 fixes the positioning piece 21 to the sealing box back cover 10. A fastening screw is provided in the hole 3.3.1 to fix the bushing 3 to the main shaft 6. The outward-folding receiving cavity 3.1 has a concave-convex part 3.2 coupled to the moving ring 1. A sealing element 25 is provided between the outer circumferential surface of the moving ring 1 and the inner wall of the outward-folding receiving cavity 3.1. An adjusting sleeve 23 is provided between the bushing 3 and the impeller 7, and an O-ring is provided on the contact surface between the adjusting sleeve 23 and the bushing 3. The components of the mechanical seal are fixed together and assembled into a containerized mechanical seal. The positioning plate is removed before use.

[0058] Example 7: Figure 10 As shown, referring to Embodiment 6, the remaining features remain unchanged, the stationary ring push elastic ring 8 is drum-shaped, and the inner side is set with spring 24.

[0059] Example 8: As Figure 11 As shown in Example 6, the bushing 3 is composed of a metal part 3.3 and a non-metal part. The outward-facing receiving cavity 3.1 of the fixed moving ring 1 is provided on the non-metal part, and the anti-rotation and anti-pull-out holes and grooves are located on the metal part 3.3. The manufacturing method can be to embed the metal part 3.3 in a metal mold and then heat-melt and mold the non-metallic material to obtain it; or the metal part and the non-metallic part can be manufactured separately and then connected together. The connection method can be to use threads or to cast with solid resin.

[0060] The non-metallic materials include one or more composites of plastics, resins, and fiberglass. The selection of non-metallic materials only needs to meet the requirements of corrosion resistance, wear resistance, rigidity, and moldability.

[0061] Example 9: As Figure 12 As shown, referring to Embodiment 1, the remaining features remain unchanged, and the sealing box 9 and the sealing box cover 10 are integrally formed.

[0062] Example 10: As Figure 12As shown, referring to Embodiment 1, with the other features unchanged, a bushing 3 is provided on the main shaft 6, the rotating ring 1 adopts an L-shaped base, the L-shaped base is riveted to the bushing 3 and a sealing element is provided on the contact surface, and the bushing 3 and the L-shaped base are provided with mutually coupled anti-rotation convex and concave parts.

[0063] Example 11: As Figure 13 As shown, referring to Embodiment 1, with the other features unchanged, a bushing 3 is provided on the main shaft 6, the connection between the rotating ring 1 and the bushing 3 adopts a hook structure and is provided with mutually coupled anti-rotation concave and convex parts, and a seal is provided between the contact surfaces of the rotating ring and the bushing.

[0064] Example 12: As Figure 14 As shown, referring to Embodiment 1, with the other features unchanged, the sealing box 9 has a liquid inlet hole 25 that connects to the liquid storage chamber 18 and is connected to an external liquid source 13. The sealing box 9 has a liquid outlet hole 26, one end of which is connected to the liquid storage chamber 18 and the other end is connected to the external liquid source 13. The liquid outlet hole 26, the liquid inlet hole 25, the liquid storage chamber 18 and the external liquid source 13 form a cooling cycle.

[0065] In the above embodiments 1 to 12, the rigid partition refers to a rigid material that is both rigid and corrosion resistant. This rigid partition 11 can be set as a separate partition structure and then assembled, or it can be made as an integral part of the sealing box 9.

[0066] The pump casing 4 and impeller 7 are manufactured using a structure lined with ultra-high molecular weight polyethylene.

[0067] The sealing box 9 and the rear cover 10 of the sealing box are made of fiberglass or plastic.

[0068] The stationary ring 2 and the moving ring 1 are made of silicon carbide material.

[0069] The stationary ring pusher ring 8 is made of nitrile rubber or fluororubber.

[0070] The bushing 3 is made of metal material, such as stainless steel.

[0071] After the bushing 3 pushes the ring 1, it is locked by the cap 5 on the main shaft 6.

[0072] The external liquid source 13 refers to an external liquid storage container or liquid inlet pipe.

[0073] The liquid in the liquid source can be either water or oil.

[0074] The material of the stationary ring push ring can be an elastic rubber material or an elastic rubber-plastic composite material. There is no limitation here, as long as it meets the requirements of corrosion resistance, temperature resistance, elasticity, and leak-proofness.

[0075] To adapt to pumps conveying slurries with high solid content, a better approach is to select hard materials to manufacture the dynamic and static rings of the mechanical seal. The hard materials refer to hard ceramics and hard metals.

[0076] The rigid partition can be made of materials with good wear resistance and corrosion resistance, such as one or more composite materials of ceramics, plastics, and fiberglass.

[0077] The spring 24 can be a single large circular spring or a combination of several small springs.

[0078] The described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A corrosion and dry grind resistant shaft seal, the shaft seal mounted on a main shaft of a centrifugal pump, the shaft seal comprising a seal cartridge assembly, a mechanical seal, the mechanical seal comprising a stationary ring, a rotating ring, characterized in that The sealing box assembly is fixed to the pump shell, the moving ring is fixed to the main shaft and is in contact with the feeding liquid in the pump cavity, the sealing box assembly comprises a sealing box, a sealing box rear cover which is arranged separately or integrally with the sealing box, and a static ring pushing elastic ring arranged in the sealing box, the static ring pushing elastic ring is compressed between the sealing box rear cover and the static ring at both ends, the static ring pushing elastic ring is in an elastic compression state, the static ring friction width is in contact with the moving ring friction width for sealing, a rigid baffle is fixed to the sealing end surface between the sealing box and the pump shell, the inner hole circumferential surface of the rigid baffle is in contact with the outer circumferential surface of the static ring for sealing, the outer circumferential surface of the static ring pushing elastic ring, the sealing box rear cover, the rigid baffle and the static ring form a liquid storage cavity, the sealing box rear cover is provided with a concave-convex ring for embedding the static ring pushing elastic ring, the convex part of the concave-convex ring is embedded on the sealing box rear cover, and the concave part is matched with one end of the static ring pushing elastic ring, the static ring pushing elastic ring is a straight cylinder with corrugation, the inner side of the straight cylinder with corrugation is provided with a steel compression ring, the static ring friction width is arranged as two flat end surfaces, a liquid storage ring groove is formed between the two adjacent friction widths, a liquid through hole is arranged in the static ring, one end of the liquid through hole is communicated with the liquid storage ring groove, and the other end is communicated with the liquid storage cavity, the two friction pairs on the static ring are arranged as one hard and one soft, the outer friction pair is made of hard material, and the inner friction pair is made of soft material.

2. A corrosion and dry-wear resistant shaft seal according to claim 1 wherein The inner hole circumferential surface of the rigid baffle is provided with at least one annular groove, and the annular groove is provided with an O-shaped sealing ring or a lip-shaped sealing ring.

3. A corrosion and dry-wear resistant shaft seal in accordance with claim 1 wherein The sealing box is provided with a liquid inlet hole communicated with the liquid storage cavity, and the liquid inlet hole is connected with an external liquid source.

4. A corrosion and dry-wear resistant shaft seal in accordance with claim 1 wherein The sealing box is additionally provided with a residue discharging hole.

5. A corrosion and dry-wear resistant shaft seal in accordance with claim 1 wherein The main shaft is provided with a shaft sleeve, and the moving ring is clamped and fixed between the shaft sleeve and the impeller.

6. A corrosion and dry-wear resistant shaft seal in accordance with claim 1 wherein The main shaft is provided with a shaft sleeve, the shaft sleeve is provided with an outwardly turned accommodating cavity for fixing the moving ring at the end close to the impeller, the moving ring is fixed in the outwardly turned accommodating cavity, the shaft sleeve is provided with anti-rotation and anti-pulling-off holes and grooves at the front side of the sealing box rear cover, a positioning sheet is arranged in the groove, a positioning rivet is used to fix the positioning sheet on the sealing box rear cover, and a fastening screw is arranged in the hole to fix the shaft sleeve on the main shaft.

7. A corrosion and dry-wear resistant shaft seal according to claim 6 wherein The shaft sleeve is composed of a metal part and a non-metal part, the outwardly turned accommodating cavity for fixing the moving ring is arranged on the non-metal part, and the anti-rotation and anti-pulling-off holes and grooves are arranged on the metal part.

8. A corrosion and dry-wear resistant shaft seal according to claim 7, wherein The outwardly turned accommodating cavity is provided with a concave-convex part coupled with the moving ring.

9. A corrosion and dry-wear resistant shaft seal according to claim 8, wherein A sealing element is arranged between the outer circumferential surface of the moving ring and the inner wall of the outwardly turned accommodating cavity.

10. A corrosion and dry-wear resistant shaft seal according to claim 6 wherein An adjusting sleeve is arranged between the shaft sleeve and the impeller, and an O-shaped sealing ring is arranged on the contact surface between the adjusting sleeve and the shaft sleeve.

11. A corrosion and dry-wear resistant shaft seal in accordance with claim 1 wherein The main shaft is provided with a shaft sleeve, the moving ring adopts an L-shaped base body, the L-shaped base body is riveted with the shaft sleeve, and a sealing element is arranged on the contact surface between the L-shaped base body and the shaft sleeve.

12. A corrosion and dry-wear resistant shaft seal in accordance with claim 1 wherein The main shaft is provided with a shaft sleeve, a hooking structure is adopted at the connecting position between the moving ring and the shaft sleeve, and anti-rotation concave-convex parts are coupled with each other, and a sealing element is arranged between the contact surfaces of the moving ring and the shaft sleeve.

13. A corrosion and dry-wear resistant shaft seal in accordance with claim 1 wherein The sealing box is provided with a liquid outlet hole, one end of the liquid outlet hole is communicated with the liquid storage cavity, the other end is communicated with an external liquid source, and the liquid outlet hole, the liquid inlet hole, the liquid storage cavity and the external liquid source form a cooling circulation.

Images