Mechanical sealing device and system
By introducing nitrogen purging and a floating ring sealing structure into the mechanical seal device, the problem of methanol volatile gas escape in chemical production is solved, achieving safe handling and environmental protection, and is suitable for chemical and petrochemical systems.
Patent Information
- Application Number
- CN202520010172.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-04
- Publication Date
- 2025-12-19
- Estimated Expiration
- 2035-11-04
AI Technical Summary
In chemical production, mechanical seal devices, when conveying volatile, flammable, and toxic methanol, may not show obvious leakage, but the volatile gases generated by the friction between the moving and stationary rings cause odors in the production environment, affecting safety and the environment. Existing technologies have not been able to effectively solve this problem.
Design a mechanical seal device that employs a main seal and a floating ring seal structure. Use nitrogen to purge leaked toxic gases. Connect a methanol separator and a collection tank through a nitrogen pipeline to achieve safe gas handling. Combined with the gas resistance seal between the floating ring and the bushing, prevent gas from escaping.
It effectively prevents the escape of toxic and harmful gases from the production site, improves production safety and environmental protection, extends the service life of floating rings, and is suitable for chemical and petrochemical systems.
Smart Images
Figure CN223690321U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to mechanical seal technical field, specifically provide a mechanical seal device and system. BACKGROUND
[0002] In chemical production, methanol is a common basic chemical raw material, is a product, also is a production raw material, is widely used in various chemical production. Methanol is a colorless liquid, volatile, flammable, and has certain toxicity. Because of its chemical properties, therefore the equipment for methanol conveying is often used centrifugal pump and canned motor pump. Canned motor pump is a kind of fully-sealed centrifugal pump, and the sealing point is fully sealed, and methanol generally does not leak. When ordinary centrifugal pump is used to transport methanol, the leakage point is mainly the mechanical seal of dynamic and static contact.
[0003] In order to improve the performance of the seal, the mechanical seal adopts double-end mechanical seal. Double-end mechanical seal is combined by two single-end seals, and the main seal is the first sealing surface, and the sealing equipment transports medium. The second sealing surface is used as auxiliary sealing and rotates under the liquid lubrication in the sealing tank. When the first sealing surface fails, the medium in the pump enters the second sealing surface through the sealing cavity, and the second sealing surface plays a sealing role to prevent the medium from leaking. Therefore, the double-end sealing as a sealing component, its performance is more reliable.
[0004] But in chemical production, the following situations are often encountered, during the operation of the equipment, the machine seal is not found to leak, but the device body and the nearby smell are larger, which greatly affects the production environment, and the nearby alarm device constantly alarms. The main reason is that the machine seal works, and its working principle is to use the friction between the two groups of dynamic ring and static ring to organize medium leakage. Because the relative friction of dynamic and static ring will generate a certain amount of heat, and the medium has volatile characteristics, the generated gas has peculiar smell, so although the equipment is working, no medium leakage is found, but the irritating gas generated by the volatilization of the medium escapes, causing the surrounding to produce peculiar smell, affecting the production environment, and bringing certain production safety. SUMMARY
[0005] The utility model provides a kind of mechanical seal device and system for the above-mentioned prior art, which is reasonable in design, safe in use and avoids the escape of peculiar smell gas.
[0006] The utility model solves the technical problems by adopting the following technical scheme:
[0007] A kind of mechanical seal device, including main shaft and machine seal shell, the shaft sleeve is externally equipped with the main shaft, and main seal chamber and floating ring seal chamber are arranged between the shaft sleeve and machine seal shell;
[0008] The upper portion of the main sealing chamber is provided with a liquid inlet, and a spring is arranged in the interior of the main sealing chamber, the spring is connected with a push ring, the push ring is connected with a movable ring, the movable ring is connected with a static ring, a sealing surface is formed between the movable ring and the static ring, and process medium enters the liquid film formed between the movable ring and the static ring through the liquid inlet.
[0009] The upper portion of the floating ring sealing chamber is provided with a gas outlet, the lower portion is provided with a gas inlet, and a floating ring is arranged in the interior of the floating ring sealing chamber, a gap is formed between the floating ring and the shaft sleeve, and gas enters the gas resistance formed between the floating ring and the shaft sleeve through the gas inlet, so that the sealing effect is achieved.
[0010] Further, a sealing ring is arranged between the push ring and the movable ring.
[0011] Further, a supporting spring is arranged between the floating rings, and a supporting ring is arranged on the supporting spring.
[0012] Further, the gap between the floating ring and the shaft sleeve is 3-5 um.
[0013] Further, the shaft sleeve is connected with the main shaft through fastening screws.
[0014] Further, the mechanical seal shell is provided with a mechanical seal cover on one side.
[0015] A mechanical sealing system comprises a mechanical sealing device, and a nitrogen pipeline is connected with an air inlet in the mechanical sealing device, and the nitrogen pipeline receives nitrogen from a factory source.
[0016] The gas outlet is connected with a gas outlet pipeline, the gas outlet pipeline is connected with a methanol separator, the methanol separator is connected with a waste gas pipeline in one way and connected with a methanol collection tank in another way.
[0017] The liquid inlet is connected with a methanol liquid inlet pipeline.
[0018] Further, a filter screen, a regulating valve and a pressure gauge are sequentially arranged on the nitrogen pipeline, and nitrogen passes through the filter screen, the regulating valve and the pressure gauge in sequence to reach the air inlet.
[0019] Further, the nitrogen entering the air inlet first reaches the mechanical seal chamber between the main sealing chamber and the floating ring sealing chamber, and then reaches the floating ring sealing chamber to form the gas resistance.
[0020] Compared with the prior art, the mechanical sealing device and system have the following outstanding advantages:
[0021] The mechanical sealing device and system of the utility model avoid the safety problems and environmental protection problems in the production site by blowing and conveying the toxic and harmful gas leaked from the mechanical seal system through nitrogen.
[0022] The floating ring and the shaft sleeve in the floating ring sealing chamber are not in contact at the two end faces (the inner diameter of the floating ring and the outer diameter of the shaft sleeve) during normal operation, the wear is relatively slow, and the service life is relatively long.
[0023] The utility model is not only suitable for chemical systems, but also can be widely used in various petrochemical systems. BRIEF DESCRIPTION OF DRAWINGS
[0024] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, the drawings in the following description are some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creative labor.
[0025] ATTACHMENT Figure 1 It is a structural schematic diagram of a mechanical sealing device;
[0026] ATTACHMENT Figure 2 It is an enlarged view of A in the mechanical sealing device;
[0027] ATTACHMENT Figure 3 It is an enlarged view of B in the mechanical sealing device;
[0028] ATTACHMENT Figure 4 It is a structural schematic diagram of a mechanical sealing system.
[0029] The marks in the drawings respectively represent:
[0030] 1, spring, 2, dynamic ring, 3, static ring, 4, sealing ring, 5, floating ring, 6, support spring, 7, support ring, 8, mechanical seal shell, 9, mechanical seal cover, 10, shaft sleeve, 11, fastening screw, 12, liquid inlet, 13, gas outlet, 14, gas inlet, 15, sealing surface, 16, floating ring end face, 17, main sealing chamber, 18, floating ring seal, 19, nitrogen pipeline, 20, filter screen, 21, setting valve, 22, pressure gauge, 23, methanol separator, 24, methanol collection tank, 25, waste gas pipeline, 26, gas pipeline, 27, methanol liquid inlet pipeline, 28, push ring, 29, main shaft. DETAILED DESCRIPTION
[0031] The utility model will be further described in connection with the drawings and specific embodiments, but not as the limitation of the utility model.
[0032] In the utility model, under the condition of not making opposite statement, the orientation words such as "up, down, left, right" usually refer to the up, down, left, right shown in the drawing;"inner, outer" refers to the inner, outer relative to the contour of each component itself.
[0033] The following is a preferred embodiment:
[0034] like Figures 1-3 As shown, a mechanical seal device in this embodiment includes a main shaft 29 and a mechanical seal housing 8. A bushing 10 is provided outside the main shaft 29. A main sealing chamber 17 and a floating ring sealing chamber 18 are provided between the bushing 10 and the mechanical seal housing 8.
[0035] The main sealing chamber 17 has an inlet 12 at the top and a spring 1 inside. The spring 1 is connected to a push ring 28, the push ring 28 is connected to a moving ring 2, the moving ring 2 is connected to a stationary ring 3, and a sealing surface 15 is formed between the moving ring 2 and the stationary ring 3. The process medium enters the space between the moving ring 2 and the stationary ring 3 through the inlet 12 to form a liquid film.
[0036] The floating ring sealing chamber 18 has an air outlet 13 at the top and an air inlet 14 at the bottom. Inside, there is a floating ring 5 with a gap between the floating ring 5 and the bushing 10. Gas enters through the air inlet 14 and forms an air resistance between the floating ring 5 and the bushing 10, thus achieving a sealing effect.
[0037] A sealing ring 4 is provided between the push ring 28 and the moving ring 2 to ensure a sealing effect.
[0038] A support spring 6 is provided between the floating rings 5 in the floating ring sealing chamber 18. A support ring 7 is provided on the support spring 6. In this embodiment, the gap between the floating ring 5 and the bushing 10 is L, which is 4 μm.
[0039] In this embodiment, the bushing 10 is connected to the spindle 29 by the fastening screw 11, ensuring the connection between the bushing 10 and the fastening screw 11.
[0040] A mechanical seal cover 9 is provided on one side of the mechanical seal housing 8. The function of the mechanical seal cover 9 is to seal the mechanical seal chamber to form a sealed cavity.
[0041] like Figure 4 As shown, a mechanical seal system in this embodiment includes a mechanical seal device, wherein the air inlet 14 of the mechanical seal device is connected to a nitrogen pipeline 19, and the nitrogen pipeline 19 receives nitrogen from the plant.
[0042] The gas outlet 13 is connected to the gas outlet pipe 26, the gas outlet pipe 26 is connected to the methanol separator 23, one of the methanol separator 23 is connected to the exhaust gas pipe 25, and the other is connected to the methanol collection tank 24; the liquid inlet 12 is connected to the methanol liquid inlet pipe 27.
[0043] The nitrogen pipeline 19 is equipped with a filter screen 20, a setting valve 21 and a pressure gauge 22 from right to left. The nitrogen gas passes through the filter screen 20, the setting valve 21 and the pressure gauge 22 in sequence to reach the air inlet 14.
[0044] The nitrogen entering the inlet 14 firstly reaches the mechanical seal chamber between the main seal chamber 17 and the floating ring seal chamber 18, and then reaches the gas barrier formed in the floating ring seal chamber 18.
[0045] In use, the mechanical seal device in the embodiment uses the main seal chamber 17 as the main seal, and bears the whole pressure of the process medium; the process medium uses methanol as the cooling liquid of the main seal chamber 17; when the equipment is running, the process medium enters the mechanical seal chamber through the liquid inlet 12, and a liquid film is formed between the dynamic ring and the static ring, thereby playing a sealing and lubricating role.
[0046] In the floating ring seal chamber 18, nitrogen is introduced from the outside to the mechanical seal chamber between the main seal chamber 17 and the floating ring seal chamber 18; the nitrogen is used as the sealing gas of the floating ring seal chamber 18; there is a 4um gap between the floating ring 5 and the shaft sleeve 10; when the equipment is running, a gas barrier is formed between the floating ring 5 and the shaft sleeve 10, thereby achieving the axial sealing effect; meanwhile, the nitrogen carries the trace process medium methanol normally leaked from the main seal chamber 17 to the methanol collection tank 24, and ensures that the working medium of the floating ring seal chamber 18 is nitrogen, so that the process medium cannot be leaked to the environment in normal operation, and the sealing effect is achieved.
[0047] In the mechanical seal system, a proper nitrogen source is introduced; the nitrogen enters the mechanical seal chamber through the nitrogen pipeline 19, the filter screen 20, the regulating valve 21 and the pressure gauge 22, carries away the generated toxic and harmful gas, passes through the methanol separator 23, and finally introduces the waste gas into the flare through the waste gas pipeline 25 for combustion.
[0048] In order to ensure the cleanliness of the gas entering the mechanical seal, a filter screen 20 with a proper precision is installed on the pipeline through which the gas enters the mechanical seal, so as to ensure the cleanliness of the gas and prevent impurities from entering the mechanical seal chamber and damaging the floating ring seal.
[0049] The on-site pressure gauge 22 and the remote pressure transmitter cooperate to detect the change of the on-site gas pressure and display the change in real time and synchronously in the DCS system. Meanwhile, the methanol collection tank 24 is added at the gas outlet, the leaked methanol is collected through the methanol separator 24, and the safety of the system is ensured.
[0050] The above-described embodiment is only one of the preferred specific embodiments of the present application, and the common changes and replacements made by those skilled in the art within the technical scheme of the present application should be included in the protection scope of the present application.
Claims
1. A mechanical seal device, characterized by, The mechanical seal device comprises a main shaft and a seal shell, a shaft sleeve is arranged outside the main shaft, a main sealing chamber and a floating ring sealing chamber are arranged between the shaft sleeve and the seal shell; An inlet is arranged on the upper part of the main sealing chamber, a spring is arranged inside, the spring is connected with a push ring, the push ring is connected with a movable ring, the movable ring is connected with a static ring, a sealing surface is formed between the movable ring and the static ring, and a liquid film is formed between the movable ring and the static ring by process medium through the inlet; An outlet is arranged on the upper part of the floating ring sealing chamber, an inlet is arranged on the lower part, a floating ring is arranged inside, a gap is formed between the floating ring and the shaft sleeve, and gas is introduced into the gap between the floating ring and the shaft sleeve through the inlet to form a gas resistance and achieve a sealing effect.
2. A mechanical seal device according to claim 1, characterized in that A sealing ring is arranged between the push ring and the movable ring.
3. A mechanical seal device according to claim 2, characterized in that Support springs are arranged between the floating rings, and support rings are arranged on the support springs.
4. A mechanical seal device according to claim 1, characterized in that The gap between the floating ring and the shaft sleeve is 3-5 um.
5. A mechanical seal device according to claim 1, wherein The shaft sleeve is connected with the main shaft through fastening screws.
6. A mechanical seal device according to claim 1, wherein A seal shell cover is arranged on one side of the seal shell.
7. A mechanical seal system characterized by, The mechanical seal device of claims 1-6, a nitrogen pipeline is connected with the inlet of the mechanical seal device, and the nitrogen pipeline receives nitrogen from a factory source; The outlet is connected with an outlet pipeline, the outlet pipeline is connected with a methanol separator, the methanol separator is connected with a waste gas pipeline in one way and connected with a methanol collection tank in another way; The inlet is connected with a methanol liquid inlet pipeline.
8. A mechanical seal system according to claim 7, wherein A filter screen, a setting valve and a pressure gauge are arranged on the nitrogen pipeline in sequence, and nitrogen passes through the filter screen, the setting valve and the pressure gauge in sequence to reach the inlet.
9. A mechanical seal system according to claim 8, wherein, The nitrogen of the inlet first reaches the seal chamber between the main sealing chamber and the floating ring sealing chamber, and then reaches the floating ring sealing chamber to form a gas resistance.