A casing hanging type thermal recovery casing head

Abstract

The present invention relates to the technical field of casing heads, specifically a casing hanging type thermal recovery casing head, comprising an upper flange seat, a casing head and a lower flange seat; the casing head is composed of a rear shell and a front shell spliced ​​together, and the rear shell is provided with a spacer bar which is plugged into the fitting groove of the front shell; a connecting pipe is provided at the lower end of the upper flange seat, and an outer thread and an annular groove are provided on the outer wall of the connecting pipe, which is screwed to the inner thread groove of the casing head; a radial limit assembly and a self-locking assembly are built into the rear shell: the radial limit block is linked to a ratchet bar through a movable seat, the pawl engages the ratchet bar and a one-way locking force is provided by an L-shaped spring piece; both the upper and lower flange seats are provided with longitudinal docking strips, which are fixed by a fastening assembly in the boss after being inserted into the casing head: the rotating pin is automatically clamped into the lateral bite groove of the longitudinal docking strip under the magnetic repulsion; the support plate drives the auxiliary limit block to be synchronously clamped through the inclined groove mechanism, and is locked in position by the hanging ear; the present invention solves the problems of difficult disassembly and high-temperature sealing failure of traditional thermal recovery casing heads, and has both rapid disassembly and high-temperature reliability.

Description

Technical Field

[0001] The invention relates to the technical field of casing heads, in particular to a casing hanging type thermal recovery casing head. Background Art

[0002] In heavy oil thermal recovery, processes like steam stimulation and SAGD require downhole tools to withstand long-term high temperatures and periodic thermal stress shocks. As a key wellhead component, the casing head fulfills the core functions of suspending the casing string, sealing the annulus, and providing an interface for subsequent completions.

[0003] Traditional thermal recovery casing heads generally use an integral threaded connection structure. Although it can achieve high-pressure sealing, the casing string needs to be cut or disassembled in its entirety during maintenance. This operation takes up to several weeks and is very likely to damage the casing body. Secondly, although the existing slip-type casing heads can be installed quickly, they are prone to sealing failure under thermal cycling loads. In addition, the slip tooth marks aggravate the damage to the casing wall under high temperature stress.

[0004] Therefore, there is an urgent need for a new casing head structure that has both high-temperature sealing reliability and rapid disassembly to break through the bottleneck that restricts thermal recovery efficiency in existing technologies. Summary of the Invention

[0005] The object of the present invention is to provide a casing hanging type thermal recovery casing head to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a casing hanging type thermal recovery casing head, comprising an upper flange seat, a casing head, and a lower flange seat, wherein the casing head is composed of a rear shell and a front shell that can be separably spliced;

[0007] A connecting pipe is provided at the lower end of the upper flange seat, which passes through the casing head and the lower flange seat in sequence. The outer wall of the connecting pipe is provided with an external thread and an annular groove, and the inner wall of the casing head is provided with an internal thread groove that is screwed together with the external thread;

[0008] At least two sets of radial limiting components are provided in the rear housing, and the components include a slidable movable seat, a radial limiting block fixed to the movable seat, and a ratchet bar linked to the movable seat; the radial limiting block is engaged in the annular groove after the pipe is screwed in, thereby achieving secondary locking of the pipe;

[0009] A self-locking assembly is provided in the rear housing, which includes a pawl engaged with the ratchet bar and an L-shaped spring piece for preventing the ratchet bar from rebounding;

[0010] The upper flange seat and the lower flange seat are both provided with longitudinal docking strips on one side close to the casing head, and the joint end of the rear shell and the front shell is provided with an insert block and a rectangular slot for accommodating the insert block;

[0011] The longitudinal butt joint strip is inserted into the sleeve head and fixed by the fastening assembly in the boss, so that the insert block forms an integral structure under the limit of the longitudinal butt joint strip, thereby realizing quick disassembly and assembly.

[0012] Preferably, a partition bar is provided on a side of the rear shell close to the front shell, and a fitting groove for accommodating the partition bar is provided on the side wall of the front shell;

[0013] The radial limiting assembly and the self-locking assembly are both arranged on the rear housing, and the internal mechanism is exposed after the front housing is disassembled.

[0014] Preferably, the movable seat is provided with a first oblique groove, and the ratchet bar is plugged into the first oblique groove via a cylindrical pin;

[0015] The upper end of the ratchet bar abuts against the bottom wall of the upper flange seat, and the lower end is provided with a No. 1 spring;

[0016] When the upper flange seat is pressed downward, the ratchet bar is pushed downward, and the movement direction is converted through the inclined surface of the first inclined groove, and the moving seat is driven to drive the radial limit block to radially engage in the annular groove.

[0017] Preferably, the middle portion of the pawl is rotatably mounted on the rear housing via a central axis, one end of the pawl engages with the ratchet bar, and the other end of the pawl abuts against the L-shaped spring piece;

[0018] The spring provides continuous pressure to lock the ratchet bar in one direction, allowing it to move downward only.

[0019] Preferably, the number of the longitudinal connecting strips is four or more and is distributed in an even number, and the insert block is provided with square openings for the longitudinal connecting strips to pass through;

[0020] After the longitudinal butt joint strip is inserted, the displacement of the insert block is restricted, thereby achieving synchronous fixation of the rear shell and the front shell.

[0021] Preferably, the fastening assembly includes a rotating pin rotatably arranged in the boss, one end of the rotating pin is provided with a connecting block and a handle, and the other end is clamped into the lateral bite groove of the side wall of the longitudinal connecting strip;

[0022] A first magnet is arranged in the boss, and a second magnet with the same magnetic pole as the first magnet is arranged on the connecting block, so that the magnetic repulsion force maintains the engaging state of the rotating pin.

[0023] Preferably, when the longitudinal butt joint strip is inserted, the inclined end of the rotating pin is lifted up until the lateral biting groove is aligned, and the magnetic repulsive force drives the rotating pin to automatically snap in;

[0024] An arc-shaped groove for accommodating a handle is provided on the outer wall of the boss, and the handle can be reversed to overcome the magnetic force to separate the rotating pin.

[0025] Preferably, the boss is provided with two sets of auxiliary positioning components, including a door frame and an auxiliary limit block;

[0026] A second oblique groove is provided on the door frame, and the clamping column is inserted into the second oblique groove and fixedly connected to the driven bar.

[0027] Preferably, one end of the driven bar is fixedly connected to the support plate, and the other end is provided with a No. 3 spring; a slot is provided on the side wall of the support plate;

[0028] When the support plate moves horizontally, the two groups of portal frames are driven to move toward each other through the inclined surface of the second inclined groove, so that the auxiliary limit blocks are engaged in or disengaged from the lateral bite groove.

[0029] Preferably, the support plate is located below the connecting block and limits its rotation; when the auxiliary limit block is engaged, the pull-out resistance of the longitudinal connecting strip is enhanced;

[0030] The No. 3 spring pushes the follower bar to reset, so that the auxiliary limit block is separated from the lateral bite groove.

[0031] Preferably, both sides of the boss are provided with a clamping assembly, the clamping assembly comprising a rotating lug, a second spring, a contact block and an L-shaped push rod;

[0032] The active end of the hanging ear is connected to the No. 2 spring and contacts the L-shaped push rod, and the driven end is a hook-shaped structure that is inserted into the slot.

[0033] Preferably, the contact block pushes the L-shaped push rod under external pressure, so that the hanging ear squeezes the second spring out of the slot;

[0034] At this time, the No. 3 spring pushes the support plate to return to its original position, releasing the engagement of the docking block limit and the auxiliary limit block.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. Compared to traditional thermal recovery casing head disassembly, which requires integral cutting or reverse-cutting, resulting in long operation cycles and the potential for casing damage, the present invention utilizes a detachable housing structure. The rear and front housings are connected via spacers and interlocking grooves, combined with a longitudinal docking bar locking mechanism to achieve modular assembly. The internal rotating pin mechanism of the boss utilizes a magnetic self-locking principle, allowing the longitudinal restraint to be released with a simple turn of the handle. During disassembly, pressing the contact block in conjunction with the hanging ear releases the support plate, simultaneously disengaging the auxiliary stop block and the rotating pin, allowing the flange seat to be quickly separated from the housing. Subsequently, the pawl is turned to release the radial stop block, significantly shortening the maintenance cycle.

[0037] 2. To address seal failure under thermal cycling conditions, this invention employs a dual structure: initial thread lock and radial mechanical hard lock. The external thread of the pipe and the internal thread groove of the casing head are screwed together to form the primary seal. When the upper flange seat is pressed downward, the ratchet bar, through the beveled groove, drives the radial stopper into the annular groove, creating a rigid lock that resists thermal stress. The pawl in the self-locking assembly is continuously compressed by the spring, and the one-way locking ratchet bar rebounds, effectively preventing the stopper from loosening due to thermal expansion and significantly improving seal stability.

[0038] 3. The rear housing, front housing, and internal components form independent modules through the assembly design of inserts and rectangular slots. During maintenance, damaged parts can be replaced specifically to avoid overall scrapping. The radial stoppers and annular grooves utilize a non-interlocking stop structure, eliminating mechanical scratches during disassembly. This protects the integrity of the pipe surface, extends the service life of the casing, and reduces the need for spare parts inventory.

[0039] 4. The boss fastening assembly integrates plug-in self-locking and push-to-lock operation. Insertion of the longitudinal butt joint automatically triggers the magnetic engagement of the pivot pin, eliminating manual alignment errors. The support plate moves through the inclined slot, driving the portal frame to simultaneously tighten the auxiliary stop block, enhancing longitudinal pull-out resistance. During disassembly, a single-point press on the contact block releases the mounting bracket lock, resets the support plate, and simultaneously releases the pivot pin and auxiliary stop block, streamlining the operation and reducing the risk of error. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a three-dimensional schematic diagram of the structure of the present invention.

[0041] Figure 2 It is a schematic diagram of the cross-section state of the structure of the present invention.

[0042] Figure 3 Schematic diagram of the explosion of the casing head of the present invention.

[0043] Figure 4 It is an exploded schematic diagram of the upper flange seat, lower flange seat, rear shell and connecting pipe of the present invention.

[0044] Figure 5 It is a three-dimensional schematic diagram of the rear housing of the present invention.

[0045] Figure 6 Schematic diagram of the ratchet bar and the movable seat of the present invention.

[0046] Figure 7 Schematic diagram of the connection between the ratchet bar, pawl and spring piece of the present invention.

[0047] Figure 8 Schematic diagram of the boss, insert block and longitudinal docking strip of the present invention.

[0048] Figure 9 It is a schematic cross-sectional view of the boss of the present invention.

[0049] Figure 10 This is a schematic diagram of the present invention showing the rotation pin and the longitudinal butt joint strip in a separated state.

[0050] Figure 11 It is a schematic diagram of the connection between the support plate and the clamping assembly of the present invention.

[0051] In the figure: 1. Upper flange seat; 2. Lower flange seat; 3. Rear shell; 301. Spacer; 4. Front shell; 5. Internal thread groove; 6. Connecting pipe; 601. External thread; 602. Annular groove; 7. Insert block; 8. Rectangular slot; 9. Longitudinal docking strip; 901. Lateral bite groove; 10. Boss; 11. Radial limit block; 12. Moving seat; 13. First inclined groove; 14. Cylindrical pin; 15. Ratchet bar; 16. No. 1 spring; 17. Pawl; 18. Shrapnel; 19. Rotating pin; 20. Connecting block; 21. Handle; 22. Support plate; 2201. Slot; 23. Ear; 24. No. 2 spring; 25. L-shaped push rod; 26. Contact block; 27. Follower bar; 28. Card column; 29. ​​Second inclined groove; 30. Door frame; 31. Auxiliary limit block; 32. No. 3 spring. DETAILED DESCRIPTION

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0053] See also Figures 1 to 11 The present invention provides a technical solution: a casing hanging type thermal recovery casing head, which includes an upper flange seat 1, a casing head, and a lower flange seat 2 from top to bottom. The lower end of the upper flange seat 1 is provided with a connecting pipe 6, which is inserted between the casing head and the lower flange seat 2. An internal thread groove 5 is provided on the inner wall of the upper half of the casing head, and an external thread 601 and an annular groove 602 are provided on the outer wall of the connecting pipe 6 in sequence. The external thread 601 is screwed with the internal thread groove 5 to achieve a preliminary sealing fixation between the connecting pipe 6 and the casing head; the casing head is provided with no less than two groups of radial limit assemblies, and the radial limit assemblies include a radial limit block 11, a movable seat 12, a ratchet bar 15, and a No. 1 spring 16. The movable seat 12 and the ratchet bar 15 are slidingly installed in the casing head. The radial limit block 11 One end is fixedly connected to the movable seat 12, and the other end of the radial limit block 11 is clamped in the annular groove 602; a first oblique groove 13 is opened through the movable seat 12, and one end of the ratchet bar 15 is fixedly connected to a cylindrical pin 14 inserted in the first oblique groove 13, and the other end of the ratchet bar 15 extends out of the upper end wall of the sleeve head and is connected with the bottom wall of the upper flange seat 1, and the ratchet bar 15 is recessed with an assembly groove on the side close to the pipe 6, and a No. 1 spring 16 is fixedly provided on the upper end wall of the assembly groove; through the cooperation of the ratchet bar 15, No. 1 spring 16, cylindrical pin 14, the first oblique groove 13 and the movable seat 12, after the upper flange seat 1 is docked with the sleeve head, the radial limit block 11 can be quickly inserted into the annular groove 602 for further limiting and fixing the docking pipe 6.

[0054] like Figure 5-7 As shown, in order to prevent the ratchet bar 15 from moving upward due to loosening of the connection between the upper flange seat 1 and the casing head during use, a self-locking component is provided in the casing head to limit the ratchet bar 15. The self-locking component includes a pawl 17 and a spring plate 18. The spring plate 18 is an L-shaped structure and one end of the spring plate 18 is fixedly arranged inside the casing head. The middle part of the pawl 17 is rotatably mounted inside the casing head via a central axis. One end of the pawl 17 is engaged with the ratchet bar 15, and the other end of the pawl 17 is in contact with the spring plate 18. The design of the pawl 17 and the spring plate 18 achieves a self-locking effect, so that the ratchet bar 15 can only be pushed downward by the upper flange seat 1, and will not move upward due to changes in the position of the upper flange seat 1, thereby allowing the radial limit block 11 to be stably engaged in the annular groove 602.

[0055] like Figure 3-5 As shown, in order to facilitate the inspection and maintenance of the connecting pipe 6 and the internal components of the casing head, the casing head is provided with a detachable structure, which includes a rear shell 3 and a front shell 4. The radial limit assembly and the self-locking assembly are both arranged on the rear shell 3. A partition bar 301 is protruding from the side of the rear shell 3 close to the front shell 4. An engaging groove for accommodating the partition bar 301 is provided on the side wall of the front shell 4. Two groups of plug-in blocks 7 are symmetrically provided at the right end of the rear shell 3 and the left end of the front shell 4. A rectangular slot 8 for accommodating the plug-in block 7 is provided at the left end of the rear shell 3 and the right end of the front shell 4.

[0056] like Figure 4 as well as Figure 8 As shown, in order to facilitate the rapid assembly of the sleeve head with the upper and lower flange seats 2, the upper flange seat 1 and the lower flange seat 2 are both protrudingly provided with a plurality of longitudinal docking strips 9 distributed in a circular array on one side close to the sleeve head. There are no less than four longitudinal docking strips 9, and the number is selected to be an even number. This arrangement can ensure that each plug-in block 7 can be plugged and limited by the longitudinal docking strips 9; each longitudinal docking strip 9 is plugged into the sleeve head and fixed by a fastening assembly; each plug-in block 7 is provided with a square opening to accommodate the longitudinal docking strips 9; in actual assembly, the rear shell 3 and the front shell 4 are first spliced ​​together, and then the upper flange seat 1 and the lower flange seat 2 are docked with the sleeve head, so that the plug-in block 7 can be limited and fixed after the longitudinal docking strips 9 are inserted into the sleeve head, thereby greatly simplifying the assembly steps.

[0057] like Figure 8-10As shown, the fastening assembly includes a boss 10, a turn pin 19, a connecting block 20 and a handle 21. The end of the longitudinal connecting strip 9 extends into the boss 10 and a lateral bite groove 901 is provided on its side wall. The middle part of the turn pin 19 is rotatably installed in the boss 10 through a pin shaft. One end of the turn pin 19 is fixedly connected to the connecting block 20, and the other end of the turn pin 19 is rotatably engaged in the lateral bite groove 901. A handle 21 is fixedly provided on the front side of the connecting block 20. The end of the handle 21 away from the connecting block 20 extends out of the boss 10 to the outside, and an arc-shaped groove for accommodating the handle 21 is provided on the outer wall of the boss 10; a first magnet is fixedly provided inside the boss 10 and is located directly above the connecting block 20. A second magnet with the same magnetic pole as the first magnet is fixedly provided on the side wall of the connecting block 20. Through the magnetic force between the like magnets, the turn pin 19 is stably engaged in the lateral bite groove 901 without being affected by external force. When the longitudinal connecting strip 9 is inserted into the boss 10, its end will first act on the inclined end of the turn pin 19 and push it upward until the lateral bite groove 901 is just located at the turn pin 19. At this time, under the repulsive force between the magnets, the turn pin 19 quickly flips downward and engages in the lateral bite groove 901.

[0058] like Figure 10-11 As shown, in order to further fix the longitudinal docking strip 9, two groups of auxiliary positioning components symmetrical about the longitudinal docking strip 9 are provided in each boss 10, and the auxiliary positioning components include a driven strip 27, a door frame 30 and an auxiliary limit block 31. The door frame 30 is slidingly installed in the boss 10 and fixedly connected to the auxiliary limit block 31. A lateral bite groove 901 for accommodating the auxiliary limit block 31 is provided on the outer wall of the longitudinal docking strip 9, and a second inclined groove 29 is provided on the door frame 30. A card column 28 is inserted in the second inclined groove 29. One end of the driven strip 27 is fixedly connected to the card column 28, and the other end of the driven strip 27 is protruding and fixedly connected to the support plate 22. The support plate 22 is slidingly installed in the boss 10 and is bottom-limited by the docking block 20, so as to prevent the turn pin 19 from reversing; and a No. 3 spring 32 is fixedly provided on the protruding end of the driven strip 27 near the side of the door frame 30. Through the design of the driven bar 27, the portal frame 30, the second inclined groove 29 and the clamping column 28, the horizontal movement of the support plate 22 can be converted into the linear movement toward each other of the two groups of portal frames 30, so that the auxiliary limit block 31 can adaptively tighten or loosen the longitudinal docking bar 9 according to the movement state of the support plate 22.

[0059] like Figure 8 as well as Figure 11As shown, the side walls of the support plate 22 are symmetrically provided with card slots 2201. In order to achieve a quick fixing effect on the support plate 22, the boss 10 is provided with a group of card connection components on both sides of the support plate 22. The card connection components include a hook 23, a No. 2 spring 24, a contact block 26 and an L-shaped push rod 25. The middle part of the hook 23 is rotatably installed in the boss 10 through a rotating shaft. The hook 23 is divided into an active end and a driven end. One side of the active end is fixedly connected with the No. 2 spring 24, and the other side of the active end is in contact with the end of the L-shaped push rod 25. The driven end is set to a hook-shaped structure and is clamped in the card slot 2201. The contact block 26 extends into the boss 10 from the outside and is fixedly connected to the L-shaped push rod 25. When the support plate 22 moves toward the connecting block 20, the driven end of the ear 23 is clamped in the slot 2201 to achieve rapid positioning of the support plate 22; when the contact block 26 is pressed to push the L-shaped push rod 25 to move toward the driven bar 27, the L-shaped push rod 25 acts on the active end of the ear 23, and the ear 23 is squeezed by the No. 2 spring 24 and pulled out of the slot 2201. At this time, under the elastic force of the No. 3 spring 32, the support plate 22 and the driven bar 27 both move in the direction away from the portal frame 30. At this time, the support plate 22 releases the bottom limiting effect on the rotating pin 19, and the auxiliary limiting block 31 is pulled out from the lateral bite groove 901 to release the longitudinal limiting effect on the longitudinal connecting strip 9.

[0060] During use: first, splice the entire sleeve head with the lower flange seat 2. At this time, under the limiting action of the longitudinal docking strip 9 on the lower flange seat 2, the rear shell 3 and the front shell 4 are preliminarily positioned. Then, the connecting pipe 6 is screwed into the sleeve head through the cooperation of the external thread 601 and the internal thread groove 5. Then, the upper flange seat 1 is spliced ​​on the upper end face of the sleeve head, and the longitudinal docking strip 9 is inserted into the boss 10 to achieve fixation, thereby greatly improving the assembly efficiency. The ratchet bar 15 drives the cylindrical pin 14 to move downward under the extrusion of the upper flange seat 1. The cylindrical pin 14 acts on the first inclined groove 13, so that the movable seat 12 is forced to drive the radial limit block 11 to quickly clamp in the annular groove 602, and the connecting pipe 6 is double-positioned. Combined with the threaded connection method, it has both high-temperature sealing reliability and quick disassembly.

[0061] When it is necessary to inspect the inside of the casing head, first press the contact block 26 to push the L-shaped push rod 25 to move in the direction of the driven bar 27. The L-shaped push rod 25 acts on the active end of the ear 23, and the ear 23 is squeezed by the force of the No. 2 spring 24 and pulled out from the slot 2201. At this time, under the elastic force of the No. 3 spring 32, the support plate 22 and the driven bar 27 are both moved in the direction away from the door frame 30. At this time, the support plate 22 releases the bottom limiting effect on the rotating pin 19, and the auxiliary limiting block 31 is pulled out from the lateral bite groove 901, thereby releasing the longitudinal limiting effect on the longitudinal docking strip 9. At this time, the handle 21 is turned counterclockwise, so that the connecting block 20 overcomes the repulsive force between the magnets and drives the rotating pin. 19 is pulled out from the lateral bite groove 901, and the longitudinal docking strips 9 can be pulled out one by one from the casing head. At this time, the upper flange seat 1 and the lower flange seat 2 are detached from the thermal recovery casing head, so as to facilitate the disassembly of the front shell 4 and the rear shell 3; and as the front shell 4 and the rear shell 3 are disassembled, the pawl 17 can be easily moved to release the locking effect of the ratchet bar 15, so that the ratchet bar 15 is quickly bounced upward under the elastic force of the No. 1 spring 16, and the cylindrical pin 14 on the ratchet bar 15 acts on the first inclined groove 13, so that the movable seat 12 is forced to pull the radial limit block 11 out of the annular groove 602, and the connecting pipe 6 can be disassembled from the rear shell 3, which is convenient for later inspection and maintenance.

[0062] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A casing hanging type thermal recovery casing head, comprising an upper flange seat, a casing head, and a lower flange seat, characterized in that: The casing head is composed of a rear shell and a front shell that can be separably spliced; A connecting pipe is provided at the lower end of the upper flange seat, which passes through the casing head and the lower flange seat in sequence. The outer wall of the connecting pipe is provided with an external thread and an annular groove, and the inner wall of the casing head is provided with an internal thread groove that is screwed together with the external thread; At least two sets of radial limiting components are provided in the rear housing, and the components include a slidable movable seat, a radial limiting block fixed to the movable seat, and a ratchet bar linked to the movable seat; the radial limiting block is engaged in the annular groove after the pipe is screwed in, thereby achieving secondary locking of the pipe; A self-locking assembly is provided in the rear housing, which includes a pawl engaged with the ratchet bar and an L-shaped spring piece for preventing the ratchet bar from rebounding; The upper flange seat and the lower flange seat are both provided with longitudinal docking strips on one side close to the casing head, and the joint end of the rear shell and the front shell is provided with an insert block and a rectangular slot for accommodating the insert block; The longitudinal docking strip is inserted into the sleeve head and fixed by the fastening assembly in the boss, so that the plug block forms an integral structure under the limit of the longitudinal docking strip, and can be quickly disassembled and assembled; the movable seat is provided with a first inclined groove, and the ratchet bar is inserted into the first inclined groove through a cylindrical pin; the upper end of the ratchet bar abuts against the bottom wall of the upper flange seat, and a No. 1 spring is provided at the lower end; when the upper flange seat is pressed downward, the ratchet bar is pushed downward, and the direction of movement is converted by the inclined surface of the first inclined groove, driving the movable seat to drive the radial limit block to radially engage the annular groove; The middle part of the pawl is rotatably mounted on the rear housing via a central axis, with one end of the pawl engaging the ratchet bar and the other end of the pawl contacting an L-shaped spring sheet; the spring sheet provides continuous pressure to lock the pawl in one direction against the ratchet bar, allowing it to move only downward; The fastening assembly includes a rotating pin rotatably arranged in the boss, one end of the rotating pin is provided with a connecting block and a handle, and the other end is clamped into the lateral biting groove of the side wall of the longitudinal connecting strip; a first magnet is provided in the boss, and a second magnet with the same magnetic pole as the first magnet is provided on the connecting block, and the magnetic repulsion force maintains the engaging state of the rotating pin.

2. The casing hanging type thermal recovery casing head according to claim 1, characterized in that: A partition bar is provided on one side of the rear shell body close to the front shell body, and an engaging groove for accommodating the partition bar is provided on the side wall of the front shell body; The radial limiting assembly and the self-locking assembly are both arranged on the rear housing, and the internal mechanism is exposed after the front housing is disassembled.

3. The casing hanging type thermal recovery casing head according to claim 1, characterized in that: The number of the longitudinal butt joint strips is four or more and is distributed in an even number, and the insert block is provided with a square opening for the longitudinal butt joint strips to pass through; After the longitudinal butt joint strip is inserted, the displacement of the insert block is restricted, thereby achieving synchronous fixation of the rear shell and the front shell.

4. The casing hanging type thermal recovery casing head according to claim 1, characterized in that: When the longitudinal butt joint strip is inserted, the inclined end of the rotating pin is lifted up until the lateral biting groove is aligned, and the magnetic repulsive force drives the rotating pin to automatically snap in; An arc-shaped groove for accommodating a handle is provided on the outer wall of the boss, and the handle can be reversed to overcome the magnetic force to separate the rotating pin.

5. The casing hanging type thermal recovery casing head according to claim 1, characterized in that: Two sets of auxiliary positioning components are arranged in the boss, including a door frame and auxiliary limit blocks; A second oblique groove is provided on the door frame, and the clamping column is inserted into the second oblique groove and fixedly connected to the driven bar.

6. The casing hanging type thermal recovery casing head according to claim 5, characterized in that: One end of the driven bar is fixedly connected to the support plate, and the other end is provided with a No. 3 spring; a slot is provided on the side wall of the support plate; When the support plate moves horizontally, the two groups of portal frames are driven to move toward each other through the inclined surface of the second inclined groove, so that the auxiliary limit blocks are engaged in or disengaged from the lateral bite groove.

7. The casing hanging type thermal recovery casing head according to claim 6, characterized in that: The support plate is located below the connecting block and limits its rotation; when the auxiliary limit block is engaged, the pull-out resistance of the longitudinal connecting strip is enhanced; The No. 3 spring pushes the follower bar to reset, so that the auxiliary limit block is separated from the lateral bite groove.

8. The casing hanging type thermal recovery casing head according to claim 6, characterized in that: Both sides of the boss are provided with a clamping assembly, which includes a rotating lug, a second spring, a contact block and an L-shaped push rod; The active end of the hanging ear is connected to the No. 2 spring and contacts the L-shaped push rod, and the driven end is a hook-shaped structure that is inserted into the slot.

9. The casing hanging type thermal recovery casing head according to claim 8, characterized in that: The contact block pushes the L-shaped push rod under external pressure, causing the mounting ear to squeeze the No. 2 spring out of the slot; At this time, the No. 3 spring pushes the support plate to return to its original position, releasing the engagement of the docking block limit and the auxiliary limit block.

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