End shaft hole dynamic sealing structure of single-tube screw conveyor

Abstract

The invention relates to the technical field of screw conveyors, in particular to an end shaft hole dynamic sealing structure of a chemical single-pipe screw conveyor. Comprising a conveying shaft rotationally connected to a rack; the flange is connected with the end cover, a through hole is formed in the middle shaft, the conveying shaft is in clearance fit with the through hole, the inner side face of the flange is coaxially connected with an end cover leakage-proof ring, and the end cover leakage-proof ring is in clearance fit with the conveying shaft. The annular limiting seat is coaxially connected to the outer side of the flange connecting end cover; the packing body is arranged between the annular limiting seat and the conveying shaft; the inner wall of the packing pressing ring is in clearance fit with the conveying shaft, the packing pressing ring comprises a flange connecting part and a pressing part, the flange connecting part is adjustably connected to the annular limiting seat through a connecting piece, and the pressing part abuts against the outer end of the packing body. According to the end shaft hole dynamic sealing structure of the spiral conveyor, the acting force of the spiral blade for pushing materials can be eliminated, the materials are prevented from being extruded into a gap between the packing and the spiral shaft, and the sealing performance is good.

Description

Technical Field

[0001] The present invention relates to the technical field of screw conveyors, and particularly to a dynamic sealing structure for the end shaft hole of a single-tube screw conveyor in the chemical industry. Background Art

[0002] Screw conveyors are widely used in fields such as grain, coal, and chemical industry for conveying various powdery and small granular materials. A single-tube screw conveyor with a circular tube as the screw housing has the material filling the tube shell and running in a closed space, which can form a material seal, effectively prevent dust emission and gas volatilization, and prevent gas from entering the next container from the feed port to the discharge port and causing gas leakage. It is widely used in the chemical industry.

[0003] The conveying screw shaft inside the screw housing must pass through the end of the housing, be supported by bearings, and be driven by a driving unit. Between the fixed housing end cover and the rotating screw shaft, the existing sealing technology mainly uses packing compression sealing. For powdery materials, due to the force of the screw blade pushing the material, the material is extruded into the gap between the packing and the screw shaft, resulting in material leakage. If the conveyed material is highly corrosive in the chemical industry, the rotating screw shaft and the inner hole of the end cover wear faster, the sealing effect of the packing is worse, the service life is shorter, and even if the packing is frequently replaced, the ideal sealing performance still cannot be achieved, which has become a bottleneck in the application of single-tube screw conveyors. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: to provide a dynamic sealing structure for the end shaft hole of a screw conveyor with a simple and compact structure, which eliminates the force of the screw blade pushing the material, prevents the material from being extruded into the gap between the packing and the screw shaft, and has good sealing performance.

[0005] To solve the above technical problem, the technical solution adopted by the present invention is:

[0006] A dynamic sealing structure for the end shaft hole of a single-tube screw conveyor, comprising:

[0007] A conveying shaft, which is rotatably connected to a frame;

[0008] A flange connection end cover, a through hole is provided at the central axis part of the flange connection end cover, the conveying shaft is in clearance fit with the through hole, and an end cover leakage prevention ring is coaxially connected to the inner side surface of the flange connection end cover, and the end cover leakage prevention ring is in clearance fit with the conveying shaft;

[0009] An annular limiting seat, which is coaxially connected to the outside of the flange connection end cover;

[0010] A packing body, which is arranged at the position between the annular limiting seat and the conveying shaft;

[0011] Packing compression ring, the inner wall of the packing compression ring is in clearance fit with the conveying shaft. The packing compression ring includes a flange connection part and a compression part. The flange connection part is adjustably connected to the annular limit seat through a connecting piece, and the compression part abuts against the outer end of the packing body;

[0012] Annular leak-proof cover, the annular leak-proof cover is coaxially connected to the conveying shaft. The axial cross-sectional shape of the annular leak-proof cover is L-shaped. An S-shaped channel is formed between the annular leak-proof cover, the flange connection end cover and the end cover leak-proof ring. A sealing ring is provided between the annular leak-proof cover and the leak-proof ring.

[0013] Furthermore, in the end shaft hole dynamic sealing structure of the above single-screw conveyor, an annular groove is provided on the outer wall of the end cover leak-proof ring, and a sealing ring is arranged at the annular groove. The width of the sealing ring is smaller than the width of the annular groove; the sealing ring is in interference fit between the annular groove and the inner wall of the annular leak-proof cover.

[0014] Furthermore, in the end shaft hole dynamic sealing structure of the above single-screw conveyor, an annular limit groove is provided outside the through hole of the flange connection end cover, and the inner end of the packing body abuts against the annular limit groove.

[0015] Furthermore, in the end shaft hole dynamic sealing structure of the above single-screw conveyor, the cross-section of the annular limit groove is an inclined surface inclined inward, and the inner end of the packing body is provided with an inclined surface matching the annular limit groove.

[0016] Furthermore, in the end shaft hole dynamic sealing structure of the above single-screw conveyor, the outer end of the packing body is provided with an inclined surface inclined outward, and the inner end of the compression part of the packing compression ring is provided with an inclined surface matching the outer end of the packing body.

[0017] Furthermore, in the end shaft hole dynamic sealing structure of the above single-screw conveyor, the connecting piece is a screw body. The flange connection part is provided with a first screw hole, and the outer end of the annular limit seat is provided with a second screw hole corresponding to the flange connection part one by one. The screw body passes through the first screw hole and the second screw hole to lock the packing compression ring and the annular limit seat to each other.

[0018] Furthermore, in the end shaft hole dynamic sealing structure of the above single-screw conveyor, the material of the packing body is polytetrafluoroethylene.

[0019] Furthermore, in the end shaft hole dynamic sealing structure of the above single-screw conveyor, the sealing ring consists of 2 piece of hole-use sealing rings clamping 1 piece of shaft-use sealing ring. The outer side of the hole-use sealing ring is in interference fit with the inner wall of the annular leak-proof cover, and the inner side of the shaft-use sealing ring is in interference fit with the bottom of the annular groove.

[0020] Further, in the end shaft hole dynamic seal structure of the above single - tube screw conveyor, it further includes a screw conveyor housing. The main shape of the screw conveyor housing is circular tubular. There is a feed inlet provided at the upper part of the screw conveyor housing near the first end, and a discharge outlet provided at the lower part of the screw conveyor housing near the second end. Two flange - connected end caps are respectively connected to both ends of the main body of the screw conveyor housing. A first screw blade and a second screw blade are wound around the conveying shaft. The spiral directions of the first screw blade and the second screw blade are opposite. The first screw blade is located on the first side of the discharge outlet, and the second screw blade is located on the second side of the discharge.

[0021] Further, in the end shaft hole dynamic seal structure of the above single - tube screw conveyor, both the first screw blade and the second screw blade are spiral - ribbon blades. There is a spiral - ribbon support tube connected between the conveying shaft and the spiral - ribbon blade. Sintered polytetrafluoroethylene tapes are wound around the surfaces of both the spiral - ribbon support tube and the conveying shaft.

[0022] The beneficial effects of the present invention are as follows: Through the specific connection structure of the packing compression ring, the packing body and the annular limit seat, and the clearance fit structure between the conveying shaft and the through - hole of the flange - connected end cap. On the one hand, the extrusion of the packing compression ring can ensure that the packing body always seals the shaft hole clearance. On the other hand, when the material temperature is relatively high and the expansion amounts of the housing and the conveying shaft are inconsistent, resulting in axial movement between the conveying shaft and the flange - connected end cap, good rotary dynamic sealing can still be maintained. By coaxially connecting an end - cap leak - proof ring to the inner side surface of the flange - connected end cap, and by connecting an annular leak - proof cover to the conveying shaft, an S - shaped channel is formed among the annular leak - proof cover, the flange - connected end cap and the end - cap leak - proof ring. By setting a sealing ring between the annular leak - proof cover and the leak - proof ring, it can effectively prevent the powdery material from getting stuck in the gap between the conveying shaft and the flange - connected end cap when the screw conveyor conveys powdery substances, and avoid the powdery material from squeezing the packing body and affecting the sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural sectional view of the end shaft hole dynamic seal structure of a single - tube screw conveyor according to Embodiment 1 of the present invention;

[0024] Figure 2 For Figure 1 the enlarged view of Part A;

[0025] Figure 3 It is a structural sectional view of the end shaft hole dynamic seal structure of a single - tube screw conveyor according to Embodiment 2 of the present invention;

[0026] Reference Numeral Explanation:

[0027] 1. Conveying shaft; 11. First screw blade; 12. Second screw blade; 13. Spiral - ribbon blade; 14. Spiral - ribbon support tube; 15. Sintered polytetrafluoroethylene tape;

[0028] 2. Flange connection end cover; 21. Through hole; 211. Annular limiting groove; 22. End cover leak-proof ring; 23. Circular groove;

[0029] 3. Annular limiting seat;

[0030] 4. Packing body; 41. Inclined surface;

[0031] 5. Packing compression ring;

[0032] 6. Screw body;

[0033] 7. Annular leak-proof cover;

[0034] 81. Hole sealing ring; 82. Shaft sealing ring;

[0035] 9. Screw conveyor housing; 91. Feed inlet; 92. Discharge outlet. Specific implementation mode

[0036] To describe the technical content, achieved purpose and effect of the present invention in detail, the following is described in conjunction with the implementation mode and with reference to the drawings.

[0037] Embodiment 1

[0038] Please refer to Figure 1 and Figure 2 , a dynamic seal structure for the end shaft hole of a single-screw conveyor, comprising:

[0039] Conveying shaft 1, the conveying shaft 1 is rotatably connected to the frame;

[0040] Flange connection end cover 2, a through hole 21 is provided at the central axis part of the flange connection end cover 2, the conveying shaft 1 is in clearance fit with the through hole 21, an end cover leak-proof ring 22 is coaxially connected to the inner side surface of the flange connection end cover 2, and the end cover leak-proof ring 22 is in clearance fit with the conveying shaft 1;

[0041] Annular limiting seat 3, the annular limiting seat 3 is coaxially connected to the outside of the flange connection end cover 2;

[0042] Packing body 4, the packing body 4 is arranged at the position between the annular limiting seat 3 and the conveying shaft 1;

[0043] Packing compression ring 5, the inner wall of the packing compression ring 5 is in clearance fit with the conveying shaft 1, the packing compression ring 5 includes a flange connection part and a compression part, the flange connection part is adjustably connected to the annular limiting seat 3 through a connecting piece, and the compression part abuts against the outer end of the packing body 4;

[0044] The annular leak-proof cover 7 is coaxially connected to the conveying shaft 1. The axial cross-sectional shape of the annular leak-proof cover 7 is L-shaped. An S-shaped channel is formed among the annular leak-proof cover 7, the flange connection end cover 2, and the end cover leak-proof ring 22. A sealing ring is provided between the annular leak-proof cover 7 and the leak-proof ring.

[0045] In the above embodiments, through the specific connection structure of the packing pressing ring 5, the packing body 4, and the annular limiting seat 3, and the clearance fit structure between the through hole 21 of the conveying shaft 1 and the flange connection end cover 2, on the one hand, the extrusion of the packing pressing ring 5 can ensure that the packing body 4 always seals the shaft hole clearance. On the other hand, when the material temperature is relatively high and the axial expansion amounts of the housing and the conveying shaft 1 are inconsistent, resulting in axial movement between the conveying shaft 1 and the flange connection end cover 2, a good rotary dynamic seal can still be maintained. By coaxially connecting an end cover leak-proof ring 22 to the inner side surface of the flange connection end cover 2, and by connecting the annular leak-proof cover 7 to the conveying shaft 1, an S-shaped channel is formed among the annular leak-proof cover 7, the flange connection end cover 2, and the end cover leak-proof ring 22. By providing a sealing ring between the annular leak-proof cover 7 and the leak-proof ring, when the screw conveyor conveys powdery substances, it can effectively prevent the powdery materials from getting stuck in the gap between the conveying shaft 1 and the flange connection end cover 2, and avoid the powdery materials from squeezing the packing body 4 and affecting the sealing performance.

[0046] As a preferred embodiment, an annular groove 23 is provided on the outer wall of the end cover leak-proof ring 22. A sealing ring is provided at the annular groove 23, and the width of the sealing ring is smaller than the width of the annular groove 23. The sealing ring is in interference fit between the annular groove 23 and the inner wall of the annular leak-proof cover 7.

[0047] In the above embodiments, since the width of the annular groove 23 is greater than the width of the sealing ring, when axial displacement occurs between the conveying shaft 1 and the flange connection end cover 2 due to the difference in thermal expansion and contraction, the sealing ring can have a certain axial displacement space in the annular groove 23, thereby ensuring the rotational sealing performance between the conveying shaft 1 and the flange connection end cover 2.

[0048] As a preferred embodiment, an annular limiting groove 211 is provided on the outer side of the through hole 21 of the flange connection end cover 2, and the inner end of the packing body 4 abuts against the annular limiting groove 211.

[0049] As a preferred embodiment, the cross-section of the annular limiting groove 211 is an inclined surface 41 that slopes inward, and the inner end of the packing body 4 is provided with an inclined surface 41 that cooperates with the annular limiting groove 211.

[0050] As a preferred embodiment, the outer end of the packing body 4 is provided with an inclined surface 41 that slopes outward, and the inner end of the pressing part of the packing pressing ring 5 is provided with an inclined surface 41 that cooperates with the outer end of the packing body 4.

[0051] In the above embodiments, by providing the inclined surface 41 structure as described above, when the pressing portion of the packing pressing ring 5 presses on the packing body 4, a component force that squeezes inward can be applied to the packing through the inclined surface 41, causing the packing to deform inward to ensure an interference seal between it and the conveying shaft 1.

[0052] As a preferred embodiment, the connecting member is a screw body 6. The flange connecting portion is provided with a first screw hole, and the outer end of the annular limiting seat 3 is provided with a second screw hole corresponding to the flange connecting portion one by one. The screw body 6 passes through the first screw hole and the second screw hole to lock the packing pressing ring 5 and the annular limiting seat 3 to each other.

[0053] In the above structure, the pressing degree of the packing pressing ring 5 acting on the packing body 4 can be adjusted by adjusting the screw body 6, so as to flexibly control the degree of inward deformation of the packing body 4.

[0054] As a preferred embodiment, the material of the packing body 4 is polytetrafluoroethylene.

[0055] As a preferred embodiment, the sealing ring consists of 2 piece of hole-use sealing rings 81 sandwiching 1 piece of shaft-use sealing ring 82. The outer side of the hole-use sealing ring 81 is in interference fit with the inner wall of the annular leak-proof cover 7, and the inner side of the shaft-use sealing ring 82 is in interference fit with the bottom of the circular groove 23 of the end cover leak-proof ring 22.

[0056] In the above embodiments, the outer side of the hole-use sealing ring 81 is in interference fit with the inner wall of the annular leak-proof cover 7, and the inner side of the shaft-use sealing ring 82 is in interference fit with the circular groove 23 of the end cover leak-proof ring 22. By alternately arranging the hole-use sealing rings 81 and the shaft-use sealing rings 82, the sealing effect between the end cover leak-proof ring 22 and the annular leak-proof cover 7 can be further increased.

[0057] As a preferred embodiment, it further includes a screw conveyor housing 9. The main shape of the screw conveyor housing 9 is a circular tube. The upper part of the screw conveyor housing 9 near the first end is provided with a feed inlet 91, and the lower part of the screw conveyor housing 9 near the second end is provided with a discharge outlet 92. Two flange connecting end covers 2 are respectively connected to both ends of the main body of the screw conveyor housing 9. A first spiral blade 11 and a second spiral blade 12 are wound around the conveying shaft 1. The spiral directions of the first spiral blade 11 and the second spiral blade 12 are opposite. The first spiral blade 11 is located on the first side of the discharge outlet 92, and the second spiral blade 12 is located on the second side of the discharge.

[0058] In the above embodiments, by setting the discharge outlet 92 at a position deviating from the end of the housing, and by providing the first spiral blade 11 and the second spiral blade 12 with opposite spiral directions, when conveying materials in a spiral manner, the acting force of the materials on the sealing part of the flange connecting end cover 2 can be reduced, and the wear of the sealing structure caused by the acting force of the materials can be reduced.

[0059] In this embodiment, the material of the sealing ring is preferably CrNi alloy, and the materials of the end cover leak-proof ring 22 and the annular leak-proof cover 7 are preferably Hastelloy C-276, which can well resist the corrosion of strong acids such as sulfuric acid and hydrofluoric acid, ensure the reliable sealing performance of the dynamic seal structure of the end shaft hole, and reduce the infiltration of environmental water vapor into the interior of the screw conveyor housing 9.

[0060] Embodiment 2

[0061] Referring to Figure 3 , on the basis of Embodiment 1, both the first spiral blade 11 and the second spiral blade 12 are spiral ribbon blades 13. A spiral ribbon support pipe 14 is connected between the conveying shaft 1 and the spiral ribbon blade 13, and sintered polytetrafluoroethylene tapes 15 are wound around the surfaces of the spiral ribbon support pipe 14 and the conveying shaft 1.

[0062] When transporting chemical materials, corrosive gas reflux usually occurs, forming strong acids, which seriously corrodes the conveying shaft 1. To solve this problem, in the above embodiments, by designing the structures of the spiral ribbon blade 13 and the spiral ribbon support pipe 14, compared with the problem that the traditional full-leaf spiral blade cannot wind the sintered polytetrafluoroethylene tape 15, in the present invention, the spiral ribbon support pipe 14 isolates the spiral blade from the conveying shaft 1, enabling both the conveying shaft 1 and the spiral ribbon support pipe 14 to be easily wound with the sintered polytetrafluoroethylene tape, so as to avoid the direct contact between the corrosive gas and the acid liquid and the surface of the conveying shaft 1, reduce the erosion corrosion of the gas reflux acid on the conveying shaft 1, and increase the service life.

[0063] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A dynamic sealing structure for the end shaft hole of a single-tube screw conveyor, characterized in that: include: A conveying shaft, the conveying shaft is rotatably connected to the frame; A flange connection end cover, wherein a through hole is provided at the central axis of the flange connection end cover, and the conveying shaft is gap-fitted with the through hole; an end cover anti-leakage ring is coaxially connected to the inner side surface of the flange connection end cover, and the end cover anti-leakage ring is gap-fitted with the conveying shaft; An annular limit seat, the annular limit seat is coaxially connected to the outer side of the flange connection end cover; The base body is arranged between the annular limiting seat and the conveying shaft; A packing clamping ring, wherein the inner wall of the packing clamping ring is in clearance fit with the conveying shaft, the packing clamping ring comprises a flange connection portion and a clamping portion, the flange connection portion is adjustably connected to the annular limit seat through a connecting piece, and the clamping portion abuts against the outer end of the packing body; An annular leak-proof cover is coaxially connected to the conveying shaft, the axial cross-section of the annular leak-proof cover is L-shaped, an S-shaped channel is formed between the annular leak-proof cover, the flange-connected end cover and the end cover leak-proof ring, and a sealing ring is provided between the annular leak-proof cover and the leak-proof ring.

2. The end shaft hole dynamic sealing structure of the single-tube screw conveyor according to claim 1 is characterized in that: The outer wall of the end cover leakproof ring is provided with an annular groove, and a sealing ring is arranged at the annular groove, and the width of the sealing ring is smaller than that of the annular groove; the sealing ring is interference fit between the annular groove and the inner wall of the annular leakproof cover.

3. The end shaft hole dynamic sealing structure of the single-tube screw conveyor according to claim 1 is characterized in that: An annular limiting groove is arranged outside the through hole of the flange connection end cover, and the inner side end of the disk root body abuts against the annular limiting groove.

4. The end shaft hole dynamic sealing structure of the single-tube screw conveyor according to claim 3 is characterized in that: The cross section of the annular limiting groove is an inclined surface inclined inwardly, and the inner side end of the base body is provided with an inclined surface matched with the annular limiting groove.

5. The end shaft hole dynamic sealing structure of the single-tube screw conveyor according to claim 1 is characterized in that: The outer side end of the packing body is provided with an outwardly inclined inclined surface, and the inner side end of the pressing part of the packing pressing ring is provided with an inclined surface matched with the outer side end of the packing body.

6. The end shaft hole dynamic sealing structure of the single-tube screw conveyor according to claim 1 is characterized in that: The connecting piece is a screw body, the flange connecting part is provided with a first screw hole, the outer end of the annular limit seat is provided with a second screw hole corresponding to the flange connecting part one by one, and the screw body passes through the first screw hole and the second screw hole to lock the packing clamping ring and the annular limit seat with each other.

7. The end shaft hole dynamic sealing structure of the single-tube screw conveyor according to claim 1 is characterized in that: The material of the base plate body is polytetrafluoroethylene.

8. The end shaft hole dynamic sealing structure of the single-tube screw conveyor according to claim 2 is characterized in that: The sealing ring is composed of two hole sealing rings and one shaft sealing ring. The outer side of the hole sealing ring is interference fit with the inner wall of the annular leak-proof cover, and the inner side of the shaft sealing ring is interference fit with the bottom of the annular groove.

9. The end shaft hole dynamic sealing structure of the single-tube screw conveyor according to claim 1, characterized in that: It also includes a screw conveyor shell, the main body of the screw conveyor shell is in the shape of a circular tube, a feed port is provided at the upper portion of the screw conveyor shell near the first end, a discharge port is provided at the lower portion of the screw conveyor shell near the second end, two flange connection end covers are respectively connected to the two ends of the main body of the screw conveyor shell, a first spiral blade and a second spiral blade are wound around the conveying shaft, the spiral directions of the first spiral blade and the second spiral blade are opposite, the first spiral blade is located on the first side of the discharge port, and the second spiral blade is located on the second side of the discharge port.

10. The end shaft hole dynamic sealing structure of the single-tube screw conveyor according to claim 9, characterized in that: The first spiral blade and the second spiral blade are both spiral blades, a spiral support tube is connected between the conveying shaft and the spiral blade, and the surfaces of the spiral support tube and the conveying shaft are both wrapped with sintered polytetrachloroethylene tape.

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