A prefabricated composite direct buried steam insulation pipe

Abstract

The present invention discloses a prefabricated composite direct-buried steam insulation pipe, comprising an inner insulation pipe, an outer insulation pipe and an insulation layer, each insulation layer is sleeved with a clamping structure, the clamping structure comprises a left pull tab and a right pull tab, the left pull tab and the right pull tab are in contact with the surface of the insulation layer, the left pull tab and the right pull tab are respectively arranged on both sides of the joint gap, the left pull tab and / or the right pull tab are connected with a driving mechanism, and adjacent clamping structures are connected by a traction assembly, the traction assembly comprises mounting seats respectively fixedly arranged on two groups of shaft sleeves and a traction rod axially slidably arranged in the two mounting seats. The present invention greatly reduces the size of the joint gap and provides a preload by respectively arranging a clamping structure on each group of insulation layers. At the same time, the two adjacent groups of clamping structures are connected by the traction assembly, so that the insulation layer on one side is fitted and abutted against the insulation layer on the other side by applying an axial traction force, so as to reduce the size of the splicing gap and improve the sealing effect.

Description

Technical Field

[0001] The invention relates to the technical field of thermal insulation pipes, and in particular to a prefabricated composite direct-buried steam thermal insulation pipe. Background Art

[0002] As the core transmission component in the urban centralized heating system, the insulation performance of direct buried steam insulated pipes directly affects the energy utilization rate and the economic efficiency of pipe network operation. Traditional prefabricated composite insulated pipes mostly adopt a multi-layer winding insulation structure. The typical structure is from the inside to the outside, which is a working steel pipe, an insulation layer and an outer protective steel pipe. The insulation layer is often wrapped in the form of a coil on the surface of the working pipe to form an overall insulation structure.

[0003] However, the existing coil insulation layer covering the working steel pipe itself has a joint gap between the end and the end, and due to the length limitation of the coil, a circumferential splicing seam is also formed between adjacent coils, causing heat to escape from the seam during transportation, resulting in heat loss.

[0004] At present, the existing technology usually uses heat-sensitive tape or connectors to pull the insulation layer so that the two sides of the joint are abutted together to achieve a sealing effect. However, in actual application, high temperature conditions can easily cause the colloid to crack, resulting in a decrease in the sealing level. In addition, when the working pipe transports steam, its axial and radial directions will undergo thermal expansion, resulting in the displacement and enlargement of the joint gap and the splicing gap. Summary of the invention

[0005] The purpose of the present invention is to provide a prefabricated composite direct-buried steam insulation pipe to solve the technical problem of poor sealing effect in the prior art.

[0006] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0007] A prefabricated composite direct-buried steam insulation pipe, comprising an inner insulation pipe and an outer insulation pipe, wherein the inner insulation pipe is wrapped with an insulation layer, the insulation layer has an axial joint gap, and there is a radial joint gap between adjacent insulation layers, and each insulation layer is sleeved with a clamping structure, the clamping structure comprises a sleeve enclosing the insulation layer and a left pull tab and a right pull tab arranged on the inner wall of the sleeve, the opposite inner side walls of the left pull tab and the right pull tab are respectively contacted with the arc surfaces on both sides of the insulation layer through friction-increasing particles, the left pull tab and the right pull tab are respectively arranged on both sides of the joint gap, the left pull tab and / or the right pull tab are connected with a driving mechanism, the driving mechanism is arranged outside the sleeve, and the driving mechanism is used to drive the left pull tab and the right pull tab to slide toward each other along the arc track of the circumferential outer wall of the insulation layer to reduce the joint gap;

[0008] Adjacent clamping structures are connected by a traction assembly, which includes mounting seats fixedly arranged on two sets of sleeves and traction rods axially slidably arranged in the two mounting seats. The traction rod is used to pull the clamping structure on one side to axially move toward the clamping structure on the other side to reduce the splicing gap.

[0009] As a preferred solution of the present invention, the shaft sleeve includes a left semicircular sleeve and a right semicircular sleeve, the bottoms of the left semicircular sleeve and the right semicircular sleeve are rotatably connected by a rotating shaft, and the left semicircular sleeve and the right semicircular sleeve are rotatably clamped and arranged on both sides of the insulation layer.

[0010] As a preferred solution of the present invention, arc-shaped grooves are respectively provided on the inner walls of the left semicircular sleeve and the right semicircular sleeve, and the arc-shaped grooves are provided along the arc-shaped trajectory of the outer wall of the insulation layer. The side walls of the arc-shaped grooves are recessed outward to form limiting grooves, and the left pull tab and the right pull tab are slidably arranged in the limiting grooves through limiting pieces.

[0011] As a preferred solution of the present invention, the arc-shaped groove at the end of the left semicircular sleeve is recessed inward to form an active chamber, and the bottom and end of the active chamber are provided with openings for communicating with the outside, and the left pull tab and the right pull tab are respectively moved out of and inserted into the active chamber through the end openings of the active chamber;

[0012] Among them, a bridge gear is arranged in the movable chamber, and both ends of the bridge gear are rotatably mounted on the inner wall of the movable chamber, the bottom of the bridge gear is meshed and connected with the outer surface of the left pull piece through teeth, and an insertion gap is arranged between the top of the bridge gear and the top surface of the movable chamber, and the insertion gap is used for the right pull piece to be movably inserted, and the right pull piece located in the insertion gap is meshed and connected with the bridge gear;

[0013] The right pull tab is connected to a driving mechanism, and the driving mechanism is used to drive the right pull tab to be inserted into the insertion gap and meshed with the bridge gear to drive the left pull tab to slide synchronously.

[0014] As a preferred solution of the present invention, the driving mechanism includes a long shaft gear and a movable component, the movable component is connected to the long shaft gear for driving the long shaft gear to rotate axially, the long shaft gear is arranged outside the shaft sleeve, and the long shaft gear is meshed and connected with the outer surface of the right pull tab.

[0015] As a preferred solution of the present invention, the movable component includes a screw sleeve, which is fixedly arranged on the right semicircular sleeve through a mounting bracket, a screw rod is connected to the screw sleeve by thread engagement, a sliding key is fixedly connected to the end of the screw rod, and an end shaft is connected to the end of the sliding key;

[0016] An axial slot is provided on the end shaft, and the sliding key is slidably arranged in the axial slot along its own length direction. The other end of the end shaft is coaxially fixedly connected with the long shaft gear, and the outer wall of the end shaft is rotatably installed on the right semicircular sleeve through a limiting sleeve.

[0017] An annular protrusion is arranged on the circumference of the inner wall of the limiting shaft sleeve, an annular groove is arranged on the circumference of the outer wall of the end shaft, and the annular protrusion is embedded in the annular groove.

[0018] As a preferred solution of the present invention, the sliding key includes a straight rod, a plurality of balls are arranged on the outer surface of the straight rod for limiting rolling, one end of the straight rod is fixedly connected to the screw rod, and the other end is slidably inserted in the axial groove, and the straight rod is connected to the inner wall of the axial groove through the balls.

[0019] As a preferred solution of the present invention, the mounting seat is fixedly arranged on the left semicircular sleeve, a fixing ear is arranged on the right semicircular sleeve, threaded holes are opened at corresponding positions of the fixing ear and the mounting seat, and a tightening bolt is movably connected in the threaded hole.

[0020] As a preferred solution of the present invention, the fixing ear is arranged at the end of the screw rod away from the long shaft gear. When the screw rod moves axially toward the long shaft gear, the tightening bolt is inserted into the threaded hole and contacts the end of the screw rod.

[0021] As a preferred solution of the present invention, a limiting slot is provided on the traction rod, and after the traction rod moves axially by a preset distance, the limiting slot is connected to the threaded hole correspondingly.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention provides a clamping structure on each set of insulation layers, and uses a driving mechanism to drive the two sides of the insulation layers to slide toward each other, thereby greatly reducing the size of the joint gap and providing a preload. At the same time, two adjacent sets of clamping structures are connected by a traction assembly, and the insulation layer on one side is made to fit and abut against the insulation layer on the other side by applying an axial traction force, so as to reduce the size of the splicing gap and improve the sealing effect. In addition, the method of tightening and abutting between the insulation layers can cope with the thermal expansion of the inner insulation pipe when conveying steam, and prevent the joint gap and the splicing gap from shifting and becoming larger when the insulation pipe expands radially and axially elastically. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0025] Figure 1 It is one of the overall structural schematic diagrams of the present invention;

[0026] Figure 2 It is a schematic diagram of the overall structure of the holding structure 6 in the present invention;

[0027] Figure 3 For the present invention Figure 2 The enlarged view of point A in the middle;

[0028] Figure 4 It is a structural schematic diagram of the active chamber of the present invention;

[0029] Figure 5 For the present invention Figure 1 The enlarged view of point B in the middle;

[0030] Figure 6 It is a schematic cross-sectional structure diagram of the middle end shaft 27 of the present invention;

[0031] Figure 7 It is a partial structural schematic diagram of the clamping structure 6 in the present invention, specifically a structural schematic diagram of the clamping structure having a tightening bolt 36;

[0032] Figure 8 This is the second schematic diagram of the overall structure of the present invention.

[0033] The numbers in the figure represent the following:

[0034] 1. Inner insulation pipe; 2. Outer insulation pipe; 3. Insulation layer; 4. Joint gap; 5. Splicing gap; 6. Holding structure; 7. Bushing; 8. Arc groove; 9. Limiting groove; 10. Friction-increasing particles; 11. Driving mechanism; 12. Traction assembly; 13. Mounting seat; 14. Traction rod; 15. Left semicircular sleeve; 16. Right semicircular sleeve; 17. Movable chamber; 18. Left pull tab; 19. Right pull tab; 20. Bridge gear; 21. Long shaft gear; 22. Movable assembly; 23. Screw sleeve; 24. Mounting bracket; 25. Screw rod; 26. Sliding key; 27. End shaft; 28. Axial slide groove; 29. ​​Limiting sleeve; 30. Annular protrusion; 31. Annular groove; 32. Straight rod; 33. Ball; 34. Fixing ear; 35. Threaded hole; 36. Tightening bolt; 37. Limiting slot; 38. Insertion gap. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0036] The present invention provides a prefabricated composite direct-buried steam insulation pipe, comprising an inner insulation pipe 1 and an outer insulation pipe 2. The inner insulation pipe 1 is wrapped with multiple insulation layers 3. Due to the length limitation of the insulation layer 3, it can only be crimped and joined in sections. Therefore, each insulation layer 3 has an axial joint gap 4, and there is a radial splicing gap 5 between adjacent insulation layers 3. Figure 1 As shown. The existence of the joint gap 4 and the splicing gap 5 will cause the steam heat to escape from the gap, accelerating the loss of temperature of the insulation pipe. For this reason, in this embodiment, a holding structure 6 is provided outside each section of the insulation layer 3. Figure 2 and Figure 3 As shown, the clamping structure 6 includes a sleeve 7 enclosed in the outer wall of the insulation layer 3 and a left pull tab 18 and a right pull tab 19 arranged on the inner wall of the sleeve 7. The opposite inner walls of the left pull tab 18 and the right pull tab 19 are respectively in contact with the arc surfaces on both sides of the insulation layer 3 through friction-increasing particles 10. The friction-increasing particles 10 can be made of high-temperature resistant rubber particles or ceramic particles to increase friction and ensure a stable connection between the friction pull tab and the insulation layer 3. The left pull tab 18 and the right pull tab 19 are respectively arranged on both sides of the joint gap 4, and the left pull tab 18 and / or the right pull tab 19 are connected to a driving mechanism 11, and the driving mechanism 11 is arranged outside the shaft sleeve 7. The driving mechanism 11 is used to drive the left pull tab 18 and the right pull tab 19 to slide toward each other along the arc trajectory of the circumferential outer wall of the insulation layer 3 to narrow the joint gap 4, that is, the left pull tab 18 and the right pull tab 19 are perpendicular to the movement direction of the joint gap 4, and the two sides of the insulation layer 3 are synchronously pulled toward the joint gap 4, so that the ends of the insulation layer 3 on both sides of the joint gap 4 abut against each other, so as to achieve the purpose of closing the joint gap 4 and preventing heat loss.

[0037] In addition, if Figure 1 As shown, in order to close the splicing gap 5 between two adjacent sections of the insulation layer 3, the present embodiment connects the adjacent clamping structures 6 via a traction assembly 12, and pulls one clamping structure 6 to slide toward the other clamping structure 6 via the traction assembly 12, so that the adjacent sections of the insulation layer 3 are abutted against each other to close the splicing gap 5.

[0038] Specifically, Figure 2 As shown, the traction assembly 12 includes mounting seats 13 fixedly disposed on two sets of shaft sleeves 7 respectively and a traction rod 14 axially slidably disposed in the two mounting seats 13. By applying a traction force to the end of the traction rod 14, the traction rod 14 pulls the clamping structure 6 on one side to move axially toward the clamping structure 6 on the other side, forming two sections of the insulation layer 3 The ends abut against each other, thereby achieving the purpose of closing the splicing gap 5.

[0039] In a specific implementation, there are two configurations for the combined use of the holding structure 6 and the traction assembly 12 .

[0040] Method 1: Figure 1As shown, two holding structures 6 form a group, which are respectively arranged at the adjacent ends of two insulation layers 3. The joint gap 4 of each insulation layer 3 is tightened by the two holding structures 6, and then the splicing gap 5 is reduced by pulling the traction rod 14. After the operation is completed, another group of holding structures 6 is set, and the above operation is repeated to form a form in which two holding structures 6 are provided on one insulation layer 3, and the holding structures 6 are arranged at the ends of the insulation layer 3. This method can achieve better fastening effect and better abutment effect between adjacent insulation layers 3.

[0041] Method 2: A holding structure 6 is synchronously arranged in the middle of each section of the insulation layer 3, and then a plurality of holding structures 6 are synchronously connected in series by using a traction rod 14 to form a Figure 8 This setting method is more convenient to operate and has higher setting efficiency.

[0042] In this embodiment, it is understandable that the specific structure of the shaft sleeve 7 can be a clamp structure with a cutout or an integrally closed ring sleeve. Another arrangement structure is provided below.

[0043] like Figure 2 As shown, the shaft sleeve 7 includes a left semicircular sleeve 15 and a right semicircular sleeve 16, the bottoms of the left semicircular sleeve 15 and the right semicircular sleeve 16 are rotatably connected by a rotating shaft, and the left semicircular sleeve 15 and the right semicircular sleeve 16 are rotatably clamped and arranged on both sides of the thermal insulation layer 3. The rotatably arranged left semicircular sleeve 15 and the right semicircular sleeve 16 have a larger opening gap, and the adjustment of the opening gap is more flexible. During installation, it is more convenient to clamp the sleeves on both sides of the thermal insulation layer 3.

[0044] Among them, Figure 4 As shown, arc-shaped grooves 8 are respectively opened on the inner walls of the left semicircular sleeve 15 and the right semicircular sleeve 16. The arc-shaped grooves 8 are opened along the arc-shaped trajectory of the outer wall of the thermal insulation layer 3. The side walls of the arc-shaped grooves 8 are recessed outward to form a limiting groove 9. The limiting grooves 9 and the arc-shaped grooves 8 are combined to form a sliding groove with a T-shaped cross-section. The left pull tab 18 and the right pull tab 19 are slidably arranged in the limiting groove 9 through a limiting member, so that the two can slide stably along a preset direction (groove opening trajectory). Example 2

[0045] On the basis of embodiment 1, this embodiment adds a bridge gear 20, see Figure 4The left pull tab 18 and the right pull tab 19 are connected by a bridge gear 20, and the left pull tab 18 and the right pull tab 19 are driven to move synchronously by a single driving mechanism 11, which not only reduces the number of driving sources used, but also improves the synchronization of the movement of the left pull tab 18 and the right pull tab 19. At the same time, each component (left pull tab 18, right pull tab 19, bridge gear 20, etc.) is separately arranged on the left semicircular sleeve 15 and the right semicircular sleeve 16 one by one, and the resulting splicing and assembly manufacturing mode can reduce the difficulty of production and improve production efficiency.

[0046] Specifically, Figure 4 As shown, the arc groove 8 at the end of the left semicircular sleeve 15 is recessed inward to form an active chamber 17, that is, the end of the arc groove 8 on the left semicircular sleeve 15 away from its bottom rotating shaft is provided with an active chamber 17, and the bottom (the side facing the left pull tab 18) and the end (the side facing the right semicircular sleeve 16) of this active chamber 17 are provided with openings for communicating with the outside (wherein, the bottom opening is used for the bridge gear 20 to mesh with the left pull tab 18, and the end opening is used for the left pull tab 18 to extend and the right pull tab 19 to insert, and the right pull tab 19 is inserted to form a linkage relationship with the left pull tab 18 by meshing with the bridge gear 20), and the left pull tab 18 and the right pull tab 19 are respectively moved out of and inserted into the active chamber 17 through the end opening of the active chamber 17.

[0047] A bridge gear 20 is provided in the active chamber 17. Both ends of the bridge gear 20 are rotatably mounted on the inner wall of the active chamber 17. The bottom of the bridge gear 20 is meshed and connected with the outer surface of the left pull piece 18 through teeth. Figure 2 and Figure 3 As shown, the top surface of the left pull tab 18 is provided with toothed teeth. A plug-in gap 38 is provided between the top of the bridge gear 20 and the top surface of the active chamber 17, see Figure 4 The insertion gap 38 is used for the right pull tab 19 to be movably inserted, and the right pull tab 19 located in the insertion gap 38 is meshed and connected with the bridge gear 20.

[0048] like Figure 3 As shown, the right pull tab 19 is connected to the driving mechanism 11, and the driving mechanism 11 is used to drive the right pull tab 19 to be inserted into the insertion gap 38 and meshed with the bridge gear 20 to drive the left pull tab 18 to slide synchronously. At the same time, based on this, the arc groove 8 and the limit groove 9 with a preset track described in Example 1 can make the sliding tracks of the left pull tab 18 and the right pull tab 19 more stable in actual application, especially during the sliding process, the right pull tab 19 can be accurately inserted into the insertion gap 38 according to the preset track and connected with the bridge gear 20.

[0049] Among them, Figure 5As shown, the driving mechanism 11 includes a long shaft gear 21 and a movable component 22. The movable component 22 is connected to the long shaft gear 21 to drive the long shaft gear 21 to rotate axially. The long shaft gear 21 is arranged outside the shaft sleeve 7, and the long shaft gear 21 is meshed and connected with the outer surface of the right pull tab 19. Example 3

[0050] Since the insulation layer 3 has a certain elasticity, after being pulled and lifted, its elastic stress may drive the left pull tab 18 and the right pull tab 19 to slide in the opposite direction (towards the bottom rotation axis). Therefore, in Example 2, a locking force can be applied to the left semicircular sleeve 15 and the right semicircular sleeve 16 by providing a fastener such as a buckle or a bolt fastener, so as to squeeze the left pull tab 18 and the right pull tab 19 inward from both sides so that the two are attached to the insulation layer 3 and pressed against the outer wall of the inner insulation pipe 1, thereby preventing the above-mentioned problem from occurring and causing the joint gap 4 to expand.

[0051] However, when the inner insulation pipe 1 is conveying steam, the heat of the high-temperature steam will cause the inner insulation pipe 1 to expand axially and radially. Therefore, the fixing effect of the indirect squeezing of the left pull tab 18 and the right pull tab 19 (locking the sleeve 7, the sleeve 7 squeezes the left pull tab 18 and the right pull tab 19) is poor. In actual application, the left pull tab 18 and the right pull tab 19 may still slide in the opposite direction in the arc groove 8 (slide toward the bottom rotation axis), thereby increasing the joint gap 4.

[0052] Therefore, on the basis of Example 2, this embodiment provides a specific structure of the movable component 22, which can not only drive the long-axis gear 21 to rotate, thereby driving the right pull tab 19 and the left pull tab 18 to slide, but also provide a pre-tightening force for the position of the long-axis gear 21 after rotation, that is, directly fix the position of the left pull tab 18 and the right pull tab 19 after sliding, so that the fixing effect is better and the risk of actual use is smaller.

[0053] Specific: such as Figure 5 As shown, the movable component 22 includes a screw sleeve 23, which is fixed on the right semicircular sleeve 16 through a mounting bracket 24. A screw rod 25 is connected to the screw sleeve 23 by threaded engagement. A sliding key 26 is fixedly connected to the end of the screw rod 25, and an end shaft 27 is connected to the end of the sliding key 26.

[0054] In this embodiment, the screw 25 is connected to the screw sleeve 23 by threads, and the tightening force of the screw 25 thread engagement is utilized to provide a maintenance effect on the lifted insulation layer 3 to prevent the gap therein from expanding.

[0055] In addition, if Figure 5 and Figure 6As shown, since the movement of the screw 25 synchronously generates circumferential rotation displacement and axial movement displacement, an axial slide groove 28 is provided on the end shaft 27 in this embodiment, and the sliding key 26 is slidably arranged in the axial slide groove 28 along its own length direction. The other end of the end shaft 27 is coaxially fixedly connected with the long shaft gear 21, and the outer wall of the end shaft 27 is rotatably installed on the right semicircular sleeve 16 through a limiting sleeve 29. An annular protrusion 30 is provided on the circumference of the inner wall of the limiting sleeve 29, and an annular groove 31 is provided on the circumference of the outer wall of the end shaft 27, and the annular protrusion 30 is embedded in the annular groove 31.

[0056] When the screw rod 25 rotates, the screw rod 25 performs a rotational propulsion motion, and at this time, the torque of its circumferential rotation is transmitted to the long-axis gear 21 through the end shaft 27, thereby driving the long-axis gear 21 to rotate synchronously. The axial linear displacement is eliminated by the sliding key 26 in the axial slide groove 28 of the end shaft 27, without pushing the long-axis gear 21 to move axially, thereby completing the positioning and rotation of the long-axis gear 21. And through the interlocking connection of the annular protrusion 30 and the annular groove 31, when the screw rod 25 rotates, the end shaft 27 and the long-axis gear 21 can be fixedly set without being pushed, so that the stabilization effect is better.

[0057] Further, such as Figure 6 As shown, in order to avoid the large resistance of the sliding key 26 in the axial slide groove 28, the present embodiment provides a specific structure of the sliding key 26. Specifically: the sliding key 26 includes a straight rod 32, and a plurality of balls 33 are set on the outer surface of the straight rod 32 for limited rolling. The limited rolling means that a plurality of grooves are opened on the straight rod 32, and the depth of the groove exceeds the radius of the ball 33, so that the ball 33 is limitedly set in the groove, but can roll in all directions. One end of the straight rod 32 is fixedly connected to the screw rod 25, and the other end is slidably inserted in the axial slide groove 28, and is connected to the inner wall of the axial slide groove 28 through the ball 33. The ball 33 is in contact with the axial slide groove 28, so that the friction resistance and internal stress between the sliding key 26 and the axial slide groove 28 are reduced by rolling the ball 33, thereby improving the smoothness of movement. Example 4

[0058] On the basis of Example 3, in order to improve the clamping ability of the left semicircular sleeve 15 and the right semicircular sleeve 16 on the thermal insulation layer 3, this embodiment is additionally provided with a fixing ear 34, see Figure 5 and Figure 7 The fixing ear 34 is fixedly arranged on the right semicircular sleeve 16, and the mounting seat 13 is fixedly arranged on the left semicircular sleeve 15. Threaded holes 35 are provided at corresponding positions of the fixing ear 34 and the mounting seat 13, and tightening bolts 36 are movably connected in the threaded holes 35.

[0059] By tightening the bolt 36 and screwing it into the fixing ear 34 and the mounting seat 13, the left semicircular sleeve 15 and the right semicircular sleeve 16 can be made to be close to each other and tightened, which can squeeze the left pull tab 18 and the right pull tab 19 so that they are more tightly connected to the insulation layer 3, and also fix the insulation layer 3 tightly against the outer wall of the inner insulation pipe 1, so that when the pipe body expands axially, especially when the pipe body is installed obliquely, it can avoid the insulation layer 3 sliding down due to the long-term application of gravity, thereby increasing the splicing gap 5. In addition, the fixing ear 34 on the other side is formed by the mounting seat 13, which can also save materials and installation processes.

[0060] Further, such as Figure 7 As shown, the fixing ear 34 is arranged at the end of the screw rod 25 away from the long shaft gear 21, and can also be arranged at the end of the long shaft gear 21 to abut against the long shaft gear 21, providing further position limitation for the long shaft gear 21. When the screw rod 25 moves axially toward the long shaft gear 21, the tightening bolt 36 is inserted into the threaded hole 35 and contacts the end of the screw rod 25.

[0061] When the screw rod 25 moves axially toward the long-axis gear 21 and is in place, that is, the insulation layer 3 is lifted into place, the tightening bolt 36 is screwed into the threaded hole 35 to complete the installation. At this time, the bolt body of the tightening bolt 36 is in contact with the end of the screw rod 25, which can limit the axial retreat of the screw rod 25 and ensure that after the screw rod 25 is screwed into place, the screw rod 25 will not be screwed out in the opposite direction, causing the left pull tab 18 and the right pull tab 19 to shift.

[0062] That is, in actual use, the thermal expansion of the tube body may cause the two ends of the single-stage insulation layer 3 to retract away from the joint gap 4, thereby causing the left pull tab 18 and the right pull tab 19 to slide in the opposite direction, and then causing the screw 25 screwed into place to rotate in the opposite direction, making the joint gap 4 larger.

[0063] After the screw rod 25 is screwed into place, the tightening bolt 36 is inserted into the threaded hole 35 so that it abuts against the end of the screw rod 25, so that the screw rod 25 cannot retreat on its own, thereby ensuring stability during use and greatly reducing the possibility of the joint gap 4 becoming larger.

[0064] Further. Figure 7As shown, a limiting slot 37 is provided on the traction rod 14. When the traction rod 14 moves axially by a preset distance so that the splicing gap 5 between the adjacent sections of the thermal insulation layer 3 is eliminated, the limiting slot 37 is connected to the threaded hole 35. In actual use, when the traction rod 14 is pulled by a preset distance, the limiting slot 37 on it will be aligned with the threaded hole 35 on the mounting seat 13, so that when the tightening bolt 36 is screwed in, it can be inserted into the limiting slot 37 synchronously, thereby synchronously limiting the traction rod 14 and ensuring the fixation of the traction rod 14. Among them, a plurality of limiting slots 37 on the traction rod 14 can be provided for easy docking. The setting of the limiting slot 37 at a preset position on the traction rod 14 can make the moving distance of the traction rod 14 more standardized and normalized.

[0065] In addition, a mounting seat 13 can be synchronously arranged at the bottom of the shaft sleeve 7, and a rolling ball can be arranged on the mounting seat 13, so that the outer thermal insulation pipe 2 can be installed more conveniently through the rolling ball. Moreover, after the outer thermal insulation pipe 2 is slidably sleeved on the mounting seat 13 through the rolling ball, in order to avoid the gap between it and the thermal insulation layer 3 affecting the thermal insulation effect, a foaming material can be injected between the thermal insulation layer 3 and the outer thermal insulation pipe 2 to fill this area, so as to improve stability and thermal insulation performance.

[0066] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A prefabricated composite direct-buried steam insulation pipe, comprising an inner insulation pipe (1) and an outer insulation pipe (2), wherein the inner insulation pipe (1) is wrapped with an insulation layer (3), the insulation layer (3) has an axial joint gap (4), and there is a radial joint gap (5) between adjacent sections of the insulation layer (3), characterized in that: Each section of the thermal insulation layer (3) is sleeved with a holding structure (6), the holding structure (6) comprising a shaft sleeve (7) enclosing the thermal insulation layer (3) and a left pull tab (18) and a right pull tab (19) arranged on the inner wall of the shaft sleeve (7), the inner side walls of the left pull tab (18) and the right pull tab (19) being opposite to each other and being in contact with the arcuate surfaces on both sides of the thermal insulation layer (3) through friction-increasing particles (10), the left pull tab (18) and the right pull tab (19) being arranged on both sides of the joint gap (4), the left pull tab (18) and / or the right pull tab (19) being connected to a driving mechanism (11), the driving mechanism (11) being arranged outside the shaft sleeve (7), the driving mechanism (11) being used to drive the left pull tab (18) and the right pull tab (19) to slide towards each other along the arcuate track of the circumferential outer wall of the thermal insulation layer (3) to reduce the joint gap (4); Adjacent clamping structures (6) are connected via a traction assembly (12), the traction assembly (12) comprising mounting seats (13) respectively fixedly arranged on two sets of shaft sleeves (7) and a traction rod (14) axially slidably arranged in the two mounting seats (13), the traction rod (14) being used to pull the clamping structure (6) on one side to axially move towards the clamping structure (6) on the other side to reduce the splicing gap (5).

2. A prefabricated composite direct buried steam insulation pipe according to claim 1, characterized in that: The shaft sleeve (7) comprises a left semicircular sleeve (15) and a right semicircular sleeve (16); the bottoms of the left semicircular sleeve (15) and the right semicircular sleeve (16) are rotatably connected via a rotating shaft; the left semicircular sleeve (15) and the right semicircular sleeve (16) are rotatably clamped and arranged on both sides of the thermal insulation layer (3).

3. A prefabricated composite direct buried steam insulation pipe according to claim 2, characterized in that: The inner walls of the left semicircular sleeve (15) and the right semicircular sleeve (16) are respectively provided with arc-shaped grooves (8), the arc-shaped grooves (8) are provided along the arc-shaped trajectory of the outer wall of the thermal insulation layer (3), the side walls of the arc-shaped grooves (8) are recessed outwards to form a limiting groove (9), and the left pull tab (18) and the right pull tab (19) are slidably arranged in the limiting groove (9) through a limiting member.

4. A prefabricated composite direct buried steam insulation pipe according to claim 3, characterized in that: The arc-shaped groove (8) at the end of the left semicircular sleeve (15) is recessed inward to form an active chamber (17); the bottom and the end of the active chamber (17) are provided with openings for communicating with the outside; the left pull tab (18) and the right pull tab (19) are respectively moved out of and inserted into the active chamber (17) through the end openings of the active chamber (17); Wherein, a bridge gear (20) is arranged in the movable chamber (17), and both ends of the bridge gear (20) are rotatably mounted on the inner wall of the movable chamber (17), and the bottom of the bridge gear (20) is meshingly connected with the outer surface of the left pull piece (18) through teeth, and an insertion gap (38) is arranged between the top of the bridge gear (20) and the top surface of the movable chamber (17), and the insertion gap (38) is used for the right pull piece (19) to be movably inserted, and the right pull piece (19) located in the insertion gap (38) is meshingly connected with the bridge gear (20); The right pull tab (19) is connected to the driving mechanism (11), and the driving mechanism (11) is used to drive the right pull tab (19) to be inserted into the insertion gap (38) and meshed with the bridge gear (20) to drive the left pull tab (18) to slide synchronously.

5. A prefabricated composite direct buried steam insulation pipe according to claim 4, characterized in that: The driving mechanism (11) comprises a long-axis gear (21) and a movable component (22); the movable component (22) is connected to the long-axis gear (21) and is used to drive the long-axis gear (21) to rotate axially; the long-axis gear (21) is arranged outside the shaft sleeve (7); and the long-axis gear (21) is meshingly connected to the outer surface of the right pull tab (19).

6. A prefabricated composite direct buried steam insulation pipe according to claim 5, characterized in that: The movable component (22) comprises a screw sleeve (23), the screw sleeve (23) is fixedly arranged on the right semicircular sleeve (16) through a mounting bracket (24), a screw rod (25) is connected in the screw sleeve (23) by means of a threaded engagement, a sliding key (26) is fixedly connected to the end of the screw rod (25), and an end of the sliding key (26) is connected to an end shaft (27); An axial slide groove (28) is provided on the end shaft (27), and the sliding key (26) is slidably arranged in the axial slide groove (28) along its length direction. The other end of the end shaft (27) is coaxially fixedly connected to the long shaft gear (21), and the outer wall of the end shaft (27) is rotatably mounted on the right semicircular sleeve (16) through a limiting sleeve (29); An annular protrusion (30) is provided on the circumference of the inner wall of the limiting shaft sleeve (29), an annular groove (31) is provided on the circumference of the outer wall of the end shaft (27), and the annular protrusion (30) is embedded in the annular groove (31).

7. A prefabricated composite direct buried steam insulation pipe according to claim 6, characterized in that: The sliding key (26) comprises a straight rod (32), a plurality of balls (33) are provided on the outer surface of the straight rod (32) for limiting rolling, one end of the straight rod (32) is fixedly connected to the screw rod (25), and the other end is slidably inserted in the axial slide groove (28), and the straight rod (32) is connected to the inner wall of the axial slide groove (28) through the balls (33).

8. A prefabricated composite direct buried steam insulation pipe according to claim 7, characterized in that: The mounting seat (13) is fixedly arranged on the left semicircular sleeve (15), and a fixing ear (34) is arranged on the right semicircular sleeve (16). A threaded hole (35) is provided at corresponding positions of the fixing ear (34) and the mounting seat (13), and a tightening bolt (36) is movably connected in the threaded hole (35).

9. A prefabricated composite direct buried steam insulation pipe according to claim 8, characterized in that: The fixing ear (34) is arranged at the end of the screw rod (25) away from the long shaft gear (21). When the screw rod (25) moves axially toward the long shaft gear (21), the tightening bolt (36) is inserted into the threaded hole (35) and contacts the end of the screw rod (25).

10. A prefabricated composite direct buried steam insulation pipe according to claim 9, characterized in that: A limit slot (37) is provided on the traction rod (14); after the traction rod (14) moves axially by a preset distance, the limit slot (37) is connected to the threaded hole (35) in correspondence.

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