Vertical circulating acid pump dry gas packing seal structure

Abstract

The utility model discloses a vertical circulating acid pump dry gas packing seal structure, including the sealing box body of installing on the pump body, the pump shaft of setting up in the sealing box body is inserted into the pump body, be provided with the seal gland on the sealing box body, the sealing clearance is formed between the sealing box body and the pump shaft, be provided with the sealing device in the sealing clearance, the sealing device includes the gas seal ring, the seal gland has the protruding compression end, the compression end inserts into the sealing clearance and is pressed to the gas seal ring fixedly, the first air inlet hole of at least one is seted up on the gas seal ring, the second air inlet hole that is corresponding and intercommunication with the first air inlet hole is seted up on the sealing box body, and the second air inlet hole is connected with the gas source, the utility model has the beneficial effect for: through injecting high pressure gas to the gas seal ring, forms two places pressure gas sealing layer, makes the acid gas sealing effect further improves, and the life of sealing member is increased greatly simultaneously.

Description

Technical Field

[0001] This utility model relates to the fields of non-ferrous smelting and environmental governance, and in particular to a dry gas packing sealing structure for a vertical circulating acid pump. Background Technology

[0002] Currently, the shaft end seals of vertical concentrated acid circulating pumps used in sulfuric acid production systems generally adopt two structural forms: the first is a packing seal; the second is a mechanical seal. In actual use, due to the positive pressure condition inside the pump tank, mixed acidic flue gas of SO2 and SO3 enters the circulating acid pump and flows into the pump shaft end sealing cavity. The pressurized acidic flue gas, through long-term impact and corrosion of the sealing packing, causes the packing to deteriorate, age, and fail. Afterward, the flue gas continuously leaks out of the pump from the sealing area, severely polluting the surrounding air. Furthermore, the leaked acidic flue gas corrodes and damages the rolling bearings on the upper part of the pump shaft, resulting in poor pump operation quality and a shortened service life.

[0003] Compared to packing seals, mechanical seals on the pump shaft offer better sealing against flue gas. However, they still pose a risk of acidic flue gas entering the mechanical seal and corroding components such as the seal springs. Furthermore, mechanical seals require high concentricity of the pump shaft rotation; even slight wear on the lower sliding bearings can damage the mechanical seal, causing the acid pump to malfunction. The original vertical circulating acid pump used a mechanical seal, which had a lifespan of approximately 4-6 months. Each mechanical seal cost 35,000 yuan, and with two pumps operating on-site, the annual cost was approximately 180,000 yuan. The mechanical seal required maintenance and replacement every 4-6 months, failing to meet continuous production requirements. Additionally, the high concentricity requirement of the mechanical seal made it susceptible to corrosion, leading to varying degrees of leakage after two months of use, polluting the air.

[0004] For example, the patent application number "CN 201020273345.1" discloses "a packing sealing structure", which can meet the sealing requirements of conventional pump bodies, but still cannot meet the sealing requirements of the pump body containing "pressurized acidic flue gas" in this application. Summary of the Invention

[0005] The purpose of this invention is to provide a dry gas packing sealing structure for a vertical circulating acid pump, which can reduce the escape of acidic gas and extend the service life of the sealing components.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A vertical circulating acid pump dry gas packing sealing structure includes a sealing housing installed on the pump body, a pump shaft extending into the pump body is provided inside the sealing housing, a sealing cover is provided on the sealing housing, a sealing gap is formed between the sealing housing and the pump shaft, a sealing device is provided in the sealing gap, the sealing device includes an air seal ring, and the sealing cover has a protruding pressing end, the pressing end extends into the sealing gap and presses and fixes the air seal ring. The air seal ring has at least one first air inlet hole, and the sealing box has a second air inlet hole that corresponds to and is connected to the first air inlet hole. The second air inlet hole is connected to an air source.

[0007] Preferably, the sealing device further includes a sealing packing located above the gas seal ring.

[0008] Preferably, the sealing device further includes a pressure-reducing sleeve located below the gas seal ring.

[0009] Preferably, the air seal ring has an outer ring groove and an inner ring groove with gradually increasing width on both sides of the first air inlet hole.

[0010] Preferably, the width of the outer ring groove is greater than the diameter of the second air inlet.

[0011] Preferably, the height of the outer ring groove is lower than the height of the inner ring groove.

[0012] Preferably, the sealing filler is made of polytetrafluoroethylene.

[0013] Preferably, the gas sealing ring and the pressure reducing sleeve are made of alloy.

[0014] Preferably, the sealing housing and the sealing gland are connected by bolts.

[0015] The beneficial effects of this utility model are as follows: 1. By injecting high-pressure gas into the gas sealing ring, two pressurized gas sealing layers are formed on the upper and lower sides of the gas sealing ring within the sealing gap. As the mixed acidic gas in the pump body flows upward, it is intercepted by the two pressurized gas sealing layers. Compared with traditional packing seals and mechanical seals, this device further improves the acid gas sealing effect and significantly increases the lifespan of the seals.

[0016] 2. The design of the pressure reducing sleeve can significantly increase the service life of the air seal ring. As the sealing gland moves down on the sealing box, its pressing end will move downward, thereby achieving the locking of the sealing gland on the sealing packing. Attached Figure Description

[0017] Figure 1 This is the overall front view of the device; Figure 2This is the front view of the sealed enclosure; Figure 3 The top view and A-A sectional view of the air seal ring are shown. Figure 4 This is the front view of the sealing gland.

[0018] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. Detailed Implementation

[0019] The present invention will now be further described with reference to the accompanying drawings. Example

[0020] like Figure 1 As shown in the figure, a vertical circulating acid pump dry gas packing sealing structure of this embodiment includes a sealing box 2 installed on the pump body (not shown in the figure), a pump shaft 1 extending into the pump body is provided in the sealing box 2, a sealing cover 6 is provided on the sealing box 2, a sealing gap is formed between the sealing box 2 and the pump shaft 1, and a sealing device is provided in the sealing gap. The sealing device includes a sealing packing 3, an air seal ring 4 and a pressure reducing sleeve 5 arranged sequentially from top to bottom.

[0021] like Figure 2 and Figure 4 As shown, the sealing housing 2 has a threaded hole 21, and the sealing cover 6 has a smooth hole 61. The cover bolt 7 passes through the smooth hole 61 and is screwed into the threaded hole 21 to connect the sealing housing 2 and the sealing cover 6. The sealing cover 6 has a protruding pressing end 62, which extends into the sealing gap. As the cover bolt 7 is tightened, the pressing end 62 gradually moves down and presses and fixes the sealing device composed of the sealing packing 3, the air seal ring 4 and the pressure reducing sleeve 5 into the sealing gap.

[0022] like Figure 3 As shown, in this embodiment, four first air inlets 41 are evenly distributed on the gas sealing ring 4, and four second air inlets 22 are also provided on the sealing housing 2. The first air inlets 41 and the second air inlets 22 correspond one-to-one, and the corresponding two air inlets are interconnected (they are coaxial). The second air inlets 22 are connected to a gas source (not shown in the figure), and the gas source outputs dry nitrogen gas at a pressure of 0.3 MPa. Gas flow is achieved through the external gas source, thereby completely isolating the inside of the pump body from the outside air and preventing the escape of harmful gases.

[0023] In other embodiments, the number of the first air inlet 41 and the second air inlet 22 can be set freely, but it is necessary to ensure that the two correspond one-to-one, and their number is generally positively correlated with the diameter of the pump shaft 1.

[0024] The air seal ring 4 has an outer ring groove 42 and an inner ring groove 43 with gradually increasing width on both sides of the first air inlet 41. This creates a pressure flow channel for air within the cavity, preventing harmful gases from escaping.

[0025] The width of the outer ring groove 42 (i.e., the distance between the upper and lower end faces) is greater than the diameter of the second air inlet 22. In fact, as... Figure 3 As shown, since the width of the outer ring groove 42 gradually increases (as it moves further away from the first air inlet 41), in this embodiment, it is only necessary to ensure that the maximum width of the outer ring groove 42 is greater than the diameter of the second air inlet 22. During assembly, the center line of the outer ring groove 42 in the height direction must coincide with the center line of the second air inlet 22 in the height direction.

[0026] The height of the outer ring groove 42 is lower than the height of the inner ring groove 43. This makes it easier for harmful gases to escape from the inner ring groove 43 that mates with the pump shaft 1. Therefore, the inner ring groove 43 is designed to be larger than the outer ring groove 42, resulting in a larger flow rate of sealing gas within the inner ring groove 43 and thus a better sealing effect.

[0027] The sealing packing 3 is made of polytetrafluoroethylene (PTFE), while the gas sealing ring 4 and the pressure reducing sleeve 5 are both made of high-temperature and concentrated acid-resistant alloys. Since the sealing device operates in a high-temperature and concentrated acid environment, selecting appropriate high-temperature and concentrated acid-resistant alloys can significantly improve the lifespan of the sealing device. PTFE possesses high-temperature resistance, concentrated acid resistance, aging resistance, high lubricity, and wear resistance; using it as the sealing packing material can further optimize the performance and reliability of the sealing device and ensure its service life.

[0028] With the above structure, due to the design of the gas sealing ring 4 and the pressure reducing sleeve 5, the sealing gas delivered from the gas source diffuses in two directions around the circumference of the gas sealing ring 4. One direction is upward, distributed along the sealing packing 3, forming a pressurized gas sealing layer on the upper part of the pump shaft 1; the other direction is downward, distributed along the pressure reducing sleeve 5, forming a pressurized gas sealing layer on the lower part of the pump shaft 1. During pump operation, the acidic gas mixed inside the pump is intercepted by the two pressurized gas sealing layers as it escapes along the pump shaft 1. A very small amount of residual gas is blocked by the sealing packing 3. At the same time, the design of the pressure reducing sleeve 5 significantly increases the lifespan of the gas sealing ring 4. Compared with traditional packing seals and mechanical seals, this device further improves the acid gas sealing effect and significantly increases the lifespan of the seals.

[0029] The table below shows the results of the applicant's detection of harmful gases inside and outside the pump body after using this sealing structure. Composition of flue gas in pump tank <![CDATA[SO₂ gas]]> <![CDATA[SO3 gas]]> <![CDATA[O2]]> <![CDATA[N2]]> Flue gas concentration detection value in pump chamber 6% 10% 10% 74% Pump dry gas packing seal device external perimeter flue gas concentration detection value 0 0 0 0

[0030] After the modification, the service life of the dry gas sealing device can reach 2 years, which can meet the production process requirements of our company. The annual maintenance and sealing cost is 0.5 million yuan. The sealing effect has been greatly improved compared with the previous one, and the corrosion of the pump shaft has been significantly improved.

[0031] During manufacturing, the inner and outer diameters of the pressure-reducing sleeve 5 are identical to those of the gas sealing ring 4. Their inner diameters form a clearance fit with the pump shaft 1, ensuring normal operation of the pump shaft 1. The pressure-reducing sleeve 5 is installed below the gas sealing ring 4 and contacts the bottom of the sealing gap (formed between the sealing housing 2 and the pump shaft 1). The design of the pressure-reducing sleeve 5 prevents the sealing gas diffusing from the gas sealing ring 4 from directly contacting the high-temperature, high-acid gas through the sealing gap. It also significantly reduces the direct contact between the gas sealing ring 4 and the high-temperature, high-acid gas, greatly increasing the effectiveness and service life of the gas sealing ring 4.

[0032] The gas sealing ring 4 has multiple through holes evenly distributed along its circumference for gas to flow between the outer ring groove 42 and the inner ring groove 43. A second air inlet 22 is provided on the side of the sealing box for connecting and supplying sealing gas from the gas source. The center line of the second air inlet 22 is a certain distance from the bottom of the sealing gap. This distance is the height of the pressure reducing sleeve plus half the height of the gas sealing ring 4.

[0033] The sealing packing 3 is positioned above the air-sealing ring 4, which provides support for it. The pressing end 62 of the sealing gland 6 directly contacts the sealing packing 3, and the sealing gland 6 and the sealing housing 2 are connected by gland bolts 7. As the gland bolts 7 are gradually tightened, the pressing end 62 of the sealing gland 6 gradually moves downward, thereby locking the sealing packing 3 in place.

[0034] The above embodiments are not intended to limit the shape, material, structure, etc. of this utility model in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this utility model shall fall within the protection scope of this utility model.

[0035] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of this utility model and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model.

[0036] If the terms "first" or "second" are used in this document to define the components, those skilled in the art should know that the use of "first" or "second" is merely for the convenience of describing this utility model and simplifying the description, and unless otherwise stated, the above terms have no special meaning.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A dry gas packing seal structure for a vertical circulating acid pump, comprising a sealing housing mounted on a pump body, a pump shaft extending into the pump body being disposed within the sealing housing, and a sealing gland being disposed on the sealing housing, characterized in that, A sealing gap is formed between the sealing housing and the pump shaft. A sealing device is provided in the sealing gap. The sealing device includes an air seal ring. The sealing cover has a protruding pressing end. The pressing end extends into the sealing gap and presses and fixes the air seal ring. The air seal ring has at least one first air inlet hole, and the sealing box has a second air inlet hole that corresponds to and is connected to the first air inlet hole. The second air inlet hole is connected to an air source.

2. The dry gas packing seal structure for a vertical circulating acid pump according to claim 1, characterized in that, The sealing device also includes sealing packing located above the gas seal ring.

3. The dry gas packing seal structure for a vertical circulating acid pump according to claim 1, characterized in that, The sealing device also includes a pressure-reducing sleeve located below the gas seal ring.

4. The dry gas packing seal structure for a vertical circulating acid pump according to claim 1, characterized in that, The air seal ring has an outer ring groove and an inner ring groove with gradually increasing width on both sides of the first air inlet.

5. The dry gas packing seal structure for a vertical circulating acid pump according to claim 4, characterized in that, The width of the outer ring groove is greater than the diameter of the second air inlet.

6. The dry gas packing seal structure for a vertical circulating acid pump according to claim 4, characterized in that, The height of the outer ring groove is lower than the height of the inner ring groove.

7. The dry gas packing seal structure for a vertical circulating acid pump according to claim 2, characterized in that, The sealing filler is made of polytetrafluoroethylene.

8. The dry gas packing seal structure for a vertical circulating acid pump according to claim 3, characterized in that, The gas sealing ring and pressure reducing sleeve are made of alloy.

9. The dry gas packing seal structure for a vertical circulating acid pump according to claim 1, characterized in that, The sealed housing and the sealing gland are connected by bolts.

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