A combined seal for a bearing housing of a blast fan for a metallurgical furnace

Abstract

This utility model discloses a bearing housing combined sealing device for a metallurgical furnace induced draft fan, comprising: a bearing housing with an annular groove on its top surface; a rotating seat fixedly connected to the rotating shaft of the induced draft fan, the bottom surface of the rotating seat having an annular boss, the annular boss and the annular groove being inserted and fitted to form a labyrinth-type radial dynamic sealing structure to prevent corrosive gases from radially flowing in; multiple centrifugal ejection inclined holes evenly distributed on the bottom outer peripheral wall of the rotating seat, the inclined direction of the centrifugal ejection inclined holes being the same as the rotation direction of the rotating shaft; and a pressure cap fixed to the top surface of the rotating seat, with a sealing ring pressed between the two to form an axial static seal. This device can effectively prevent corrosive gases from entering the bearing housing, has reliable performance, and provides a basic guarantee for the long-term operation of the metallurgical furnace induced draft fan.

Description

Technical Field

[0001] This utility model relates to the field of sealing technology for the end cover of a fan bearing seat, and more specifically to a combined sealing device for a bearing seat of a metallurgical furnace induced draft fan. Background Technology

[0002] In induced draft fan systems for metallurgical furnaces, traditional designs typically employ simple lip seals and packing seals at the dynamic seal between the fan casing and the shaft. These sealing systems present significant risks during long-term operation: the seals are prone to failure, allowing corrosive gases (including acidic media) to escape axially. Furthermore, regardless of whether the bearing housing end cover uses a felt ring seal or a skeleton oil seal, both are susceptible to failure. The function of preventing external impurities from entering is lost, allowing corrosive gases to easily penetrate the bearing housing along the gap between the fan shaft and the end cover, causing bearing corrosion, grease failure, and ultimately, equipment malfunction.

[0003] Before this utility model of the equipment, the two sealing methods were generally replaced, which had the following drawbacks.

[0004] 1. The rotor needs to be removed and the impeller taken out before replacement can be performed, which takes more than 12 hours.

[0005] 2. If there is no backup machine, production must be stopped to cooperate, which will have a significant impact on production.

[0006] 3. If there is a standby machine, the sealing of the duct ventilation valve is poor, and a large amount of gas will leak during the maintenance process, making it difficult to guarantee the safety of the workers.

[0007] Therefore, how to provide a bearing housing combination sealing device for metallurgical furnace induced draft fans that can effectively prevent the intrusion of corrosive gases, has a simple structure, and is reliable and durable is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0008] In view of this, the present invention provides a bearing housing combination sealing device for metallurgical furnace induced draft fans that can effectively prevent the intrusion of corrosive gases, has a simple structure, and is reliable and durable.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A bearing housing combined sealing device for an induced draft fan in a metallurgical furnace includes:

[0011] The bearing housing has an annular groove on its top surface;

[0012] The rotating seat is fixedly connected to the shaft of the induced draft fan so that it can rotate together with the shaft. The bottom end face of the rotating seat has an annular boss. The annular boss and the annular groove are inserted and matched to form a labyrinth-type radial dynamic sealing structure to prevent corrosive gas from flowing in radially. Multiple centrifugal gas throwing inclined holes are evenly distributed on the bottom outer peripheral wall of the rotating seat to throw out the leaked gas by the centrifugal force of rotation. The inclination direction of the centrifugal gas throwing inclined holes is the same as the rotation direction of the shaft.

[0013] A pressure cap is fixed to the top surface of the rotating seat, and a sealing ring for forming an axial static seal is pressed between the two.

[0014] As can be seen from the above technical solution, compared with the prior art, this utility model discloses a bearing housing combined sealing device for a metallurgical furnace induced draft fan. The rotating seat is fixed to the rotating shaft of the induced draft fan, so that the rotating seat rotates with the rotating shaft. In this way, the sealing ring on the rotating seat is a static seal, which can completely block the corrosive gas from entering the bearing housing along the axial intrusion path (between the rotating shaft and the end cover). This avoids the problem of poor sealing effect caused by friction damage between the fixed sealing ring and the rotating shaft. Furthermore, the device uses a labyrinth-type radial dynamic sealing structure with grooves and bosses. When the external corrosive gas passes through the multi-stage tortuous channel, the flow rate is reduced by the throttling effect, which effectively prevents the corrosive gas from flowing radially into the bearing housing. At the same time, the centrifugal throwing oblique hole generated by the rotation of the rotating seat generates centrifugal force (the higher the rotation speed, the greater the centrifugal force), which throws the gas located on the outside of the rotating seat, especially close to the labyrinth-type radial dynamic sealing structure, outward. That is, it throws this part of the gas away from the labyrinth-type radial dynamic sealing structure, further inhibiting the gas from entering the bearing housing from the location of the labyrinth-type radial dynamic sealing structure.

[0015] Therefore, this device adopts a combination of axial static sealing with sealing rings, radial labyrinth sealing with grooves, and centrifugal venting holes that throw out leaked gas by rotating centrifugal force. This can effectively prevent corrosive gases from entering the bearing housing, solve the problems of easy failure and complex maintenance of traditional seals, and has the advantages of simple structure, reliable sealing, and easy disassembly and assembly, meeting the long-cycle operation requirements of induced draft fans in metallurgical furnaces.

[0016] Furthermore, multiple tightening screws are evenly distributed and screwed onto the rotating seat, and the multiple tightening screws are tightened and fixed to the outer peripheral wall of the rotating shaft.

[0017] The beneficial effect of adopting the above technical solution is that it facilitates the quick assembly and disassembly of the rotating seat and the rotating shaft.

[0018] Furthermore, the pressure cap is fixed to the top surface of the rotating seat by fixing bolts.

[0019] The beneficial effect of adopting the above technical solution is that it facilitates the quick assembly and disassembly of the pressure cap and the rotating seat.

[0020] Furthermore, the sealing ring is made of high-temperature and corrosion-resistant fluororubber or silicone rubber, and the compression is 20%-30% of the cross-sectional diameter.

[0021] Furthermore, the axial gap between the annular boss and the annular groove is 1-1.4 mm, and the radial gap is 0.6-0.8 mm. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 An exploded structural diagram of a bearing housing combined sealing device for a metallurgical furnace induced draft fan provided by this utility model.

[0024] Figure 2 This utility model provides an assembly structure diagram of a bearing housing combined sealing device for a metallurgical furnace induced draft fan.

[0025] Figure 3 for Figure 2 A schematic cross-sectional view of the mid-section AA.

[0026] Figure 4 for Figure 2 A magnified schematic diagram of the structure of part B in the middle. Detailed Implementation

[0027] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0028] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying 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 limitations on this utility model.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] See Figures 1-4 As shown in the figure, this utility model embodiment discloses a bearing housing combined sealing device for a metallurgical furnace induced draft fan, comprising:

[0032] Bearing housing 1, which is the felt seal seat of the original induced draft fan, has an annular groove 11 machined on its top surface. The position of the annular groove 11 should be as outward as possible. The depth of the annular groove 11 is 4-6mm, the width is 8-10mm, and the roughness Ra≤3.2μm. In principle, it should not penetrate the bearing chamber.

[0033] Rotary seat 2 is fixedly connected to the shaft of the induced draft fan so that it can rotate together with the shaft. The bottom end face of the rotary seat 2 has an annular boss 21 with the following dimensions: radial height ≥ 5 mm and axial width ≥ 8 mm. The annular boss 21 and the annular groove 11 are inserted and fitted to form a labyrinth-type radial dynamic sealing structure to prevent corrosive gas from flowing in radially. Multiple centrifugal ejection inclined holes 22 are evenly distributed on the bottom outer peripheral wall of the rotary seat 2 to eject leaking gas by rotating centrifugal force. The inclination angle of the centrifugal ejection inclined holes 22 can be 45° and the diameter is 12 mm. The inclination direction of the centrifugal ejection inclined holes 22 is the same as the rotation direction of the shaft.

[0034] The pressure cap 3 is fixed on the top surface of the rotating seat 2, and a sealing ring 4 for forming an axial static seal is pressed between the two.

[0035] Multiple tightening screws 5 are evenly distributed on the rotating seat 2. The multiple tightening screws 5 are tightened and fixed to the outer peripheral wall of the rotating shaft (bolt torque 50-80 N·m). The coaxiality error between the rotating seat 2 and the rotating shaft is ≤0.05 mm.

[0036] The rotating seat 2 is tightened with the fan shaft by the tightening screw 5 to form a whole. In other words, the sealing ring is a static seal, which can completely block axial gas.

[0037] The pressure cap 3 is fixed to the top surface of the rotating seat 2 by fixing bolts 6.

[0038] The sealing ring 4 is made of high-temperature and corrosion-resistant fluororubber or silicone rubber, which meets the requirements of acid and alkali resistance and high temperature resistance (-40℃~200℃). The cross-sectional diameter is selected according to the sealing pressure (usually 5-8mm), and the compression is 20%-30% of the cross-sectional diameter.

[0039] The axial clearance between the annular boss 21 and the annular groove 11 is 1-1.4 mm, and the radial clearance is 0.6-0.8 mm.

[0040] For example, the axial clearance requirements for grooves and bosses are: 1mm at low speed and 1.4mm at high speed. The amount of shaft runout should be fully considered during assembly. The radial clearance requirements for grooves and bosses are: 0.6mm at low speed and 0.8mm at high speed. The amount of shaft runout should be fully considered during assembly. If the shaft runout is large, the radial clearance can be appropriately increased.

[0041] The installation steps of this utility model device are as follows:

[0042] Bearing housing modification: Remove the original bearing housing end cover and machine the bearing housing end face to form an annular groove with a depth of 4-6mm and a width of 8-10mm, with a roughness Ra≤3.2μm.

[0043] Rotary seat assembly: Insert the rotary seat into the rotating shaft of the induced draft fan and tighten it with the jacking bolts (bolt torque 50-80 N·m) to ensure synchronous rotation with the shaft, with a coaxiality error ≤0.05 mm.

[0044] Labyrinth structure alignment: Reset the bearing housing so that the annular groove aligns with the annular boss of the rotating seat. Adjust the radial clearance (0.6mm at low speed, 0.8mm at high speed) and axial clearance (1mm at low speed, 1.4mm at high speed) between the two, and reserve space for shaft movement (±0.5mm).

[0045] Installation of sealing ring and gland: Install the sealing ring in the annular groove of the rotating seat; install the gland and tighten the fixing bolts evenly so that the sealing ring is compressed by 20%-30% (i.e., the cross-sectional diameter is compressed by 1-2mm) to form an axial static seal.

[0046] Inclined hole direction verification: Confirm that the inclination direction of the centrifugal air ejection inclined hole is consistent with the rotation direction of the shaft (this can be verified by the fan rotation mark or trial operation) to ensure that the gas is discharged outward under the action of centrifugal force when rotating.

[0047] The sealing principle of this utility model device is as follows:

[0048] Axial sealing: Under the pressure of the gland, the sealing ring tightly fills the gap between the rotating seat and the gland, forming a static sealing surface, blocking the intrusion path of corrosive gas along the axial direction (between the rotating shaft and the end cover).

[0049] Radial sealing: The annular groove of the bearing housing and the annular boss of the rotating seat form a labyrinth structure. The gas needs to pass through multiple tortuous channels (radial clearance 0.6-0.8mm, axial clearance 1-1.4mm), and then the flow rate is reduced by the throttling effect. Combined with the centrifugal throwing oblique hole, the leaked gas is thrown out, forming a dynamic barrier.

[0050] Centrifugal air ejection: When a small amount of gas leaks into the rotating seat area through the fan casing, the inclined holes that rotate with the rotating seat generate centrifugal force (the higher the rotation speed, the greater the centrifugal force), which throws the gas located outside the rotating seat, especially the gas close to the labyrinth radial dynamic seal structure, outward. This part of the gas is thrown away from the labyrinth radial dynamic seal structure, further inhibiting the gas from entering the bearing housing from the location of the labyrinth radial dynamic seal structure.

[0051] The disassembly and assembly efficiency of this utility model is as follows: replacing the sealing device does not require removing the impeller, only the gland and sealing ring need to be removed. When installing the sealing ring, it is first cut, then glued, and then pressed in. The maintenance time for a single maintenance is ≤0.5 hours, saving 95% of maintenance time compared with the traditional method.

[0052] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bearing housing combined sealing device for an induced draft fan in a metallurgical furnace, characterized in that, include: Bearing housing (1), wherein an annular groove (11) is provided on the top surface of the bearing housing (1); Rotary seat (2), which is fixedly connected to the shaft of the induced draft fan so as to rotate together with the shaft. The bottom end face of the rotary seat (2) has an annular boss (21). The annular boss (21) and the annular groove (11) are inserted and fitted to form a labyrinth-type radial dynamic sealing structure to prevent corrosive gas from flowing in radially. Multiple centrifugal ejection inclined holes (22) are evenly distributed on the bottom outer peripheral wall of the rotary seat (2) to eject leaking gas by rotating centrifugal force. The inclination direction of the centrifugal ejection inclined holes (22) is the same as the rotation direction of the shaft. A pressure cap (3) is fixed to the top surface of the rotating seat (2), and a sealing ring (4) for forming an axial static seal is pressed between the two.

2. The bearing housing combined sealing device for a metallurgical furnace induced draft fan according to claim 1, characterized in that, Multiple tightening screws (5) are evenly distributed on the rotating seat (2), and the multiple tightening screws (5) are tightened and fixed to the outer peripheral wall of the rotating shaft.

3. The bearing housing combined sealing device for a metallurgical furnace induced draft fan according to claim 1, characterized in that, The pressure cap (3) is fixed to the top surface of the rotating seat (2) by fixing bolts (6).

4. The bearing housing combined sealing device for a metallurgical furnace induced draft fan according to claim 1, characterized in that, The sealing ring (4) is made of high-temperature and corrosion-resistant fluororubber or silicone rubber, and the compression is 20%-30% of the cross-sectional diameter.

5. The bearing housing combined sealing device for a metallurgical furnace induced draft fan according to claim 1, characterized in that, The axial gap between the annular boss (21) and the annular groove (11) is 1-1.4 mm, and the radial gap is 0.6-0.8 mm.

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