Ground freezing device

Abstract

The invention discloses a stratum freezing device, comprising an outer tube and an inner tube, a medium outlet is provided through the side wall of the outer tube, a conical sealing tube bottom is provided at the lower end of the outer tube, a medium inlet is provided at the upper end of the inner tube, the outer tube is a concentric reducer, a sealing clamp is provided in the inner cavity of the outer tube, the sealing clamp is placed above the medium outlet to fix the outer wall of the inner tube, a contact is vertically connected to the lower part of the inner tube, and a medium channel is provided between the inner tube and the contact. Through the arrangement of the outer tube, the inner tube and the sealing clamp, the purpose of achieving staged stratum freezing, local freezing and enhanced local freezing can be achieved simultaneously.

Description

Technical Field

[0001] The invention belongs to the technical field of freezing well drilling, and in particular relates to a stratum freezing device. Background Art

[0002] In recent years, the freezing method of shaft drilling construction technology has been used more and more widely, especially for coal mine shaft construction with thick alluvial layers, which can effectively play a role in safety and speed. The freezing method of shaft drilling construction uses artificial freezing technology to freeze the water-bearing soil and rock mass around the shaft, forming a frozen wall that resists ground pressure and water pressure to cut off hydraulic connection, which plays a role of temporary reinforcement to ensure the safe construction of the shaft. The shaft often passes through deep strata, and the use of a full-depth freezing method often results in a waste of cold energy. If the differential pipe freezing method is used, the lower section of the frozen wall is sometimes slow or difficult to close. The water-rich bedrock section or aquifer will be a weak part of the frozen wall. Simply using the local weak position as the control condition will often cause other positions to freeze excessively, making shaft excavation difficult, wasting cold energy, and extending the construction period.

[0003] A Chinese invention patent with application number CN202010195246.4 records a two-way enhanced freezing device and a working method, and proposes a technical solution of welding steel sheets on the freezing pipe to increase the heat exchange area, and inserting the two-way enhanced freezing device into the weak position of the soft stratum or the freezing wall to enhance the freezing effect, but this technical solution is difficult to construct and has high construction cost; a Chinese invention patent with application number CN202010134041.5 records a freezer and a method for freezing in stages, including a liquid distribution ring, a liquid collection ring, a tee, a freezing pipe, an upper freezing supply The bottom ends of the upper freezing liquid supply pipe, the lower freezing liquid return pipe and the lower freezing liquid supply pipe extend into the freezing pipe along the axis of the freezing pipe, and the upper ends of the upper freezing liquid supply pipe, the lower freezing liquid return pipe and the lower freezing liquid supply pipe extend out of the top of the freezing pipe; the distance between the bottom end of the lower freezing liquid supply pipe and the bottom of the freezing pipe is smaller than the distance between the upper freezing liquid supply pipe and the lower freezing liquid return pipe and the bottom of the freezing pipe. The technical solution can reasonably use the cold capacity for freezing in stages and accelerate the freezing of the upper part of the wellbore, but the freezer is complex in structure and difficult to operate, and when freezing the upper section, there is also brine circulation in the lower section, and the effect is not good. For this reason, a formation freezing device is designed. Summary of the invention

[0004] The object of the present invention is to provide a ground freezing device to solve the problem in the background technology that it is impossible to simultaneously realize ground freezing in stages, local freezing and enhanced local freezing.

[0005] To achieve the above purpose, the specific technical solution of a ground freezing device of the present invention is as follows:

[0006] A stratum freezing device comprises an outer tube and an inner tube, wherein a medium outlet is provided through the side wall of the outer tube, a conical sealing tube bottom is provided at the lower end of the outer tube, and a medium inlet is provided at the upper end of the inner tube. The outer tube is a concentric reducing tube, and a sealing card is provided in the inner cavity of the outer tube. The sealing card is placed above the medium outlet to fix the outer wall of the inner tube, a contact is vertically connected to the lower part of the inner tube, and a medium channel is provided between the inner tube and the contact.

[0007] Furthermore, the sealing card includes a sealing sleeve and a sealing insert. The sealing sleeve is penetrated by a vertical pipe opening, the inner diameter of the pipe opening is larger than the outer diameter of the inner tube, the sealing sleeve is sealed to the inner wall of the outer tube, and the sealing insert is sealingly clamping the outer wall of the inner tube to seal the pipe opening.

[0008] Furthermore, the pipe opening includes an internally threaded pipe.

[0009] Furthermore, the internally threaded tube is a tapered internally threaded tube that is thicker at the top and thinner at the bottom.

[0010] Furthermore, the sealing insert includes a threaded clamp and a sealing plug used with the internal threaded pipe, the threaded clamp is penetrated by a through hole, and the sealing plug is sealed and fitted with the through hole.

[0011] Furthermore, the through hole is a tapered hole that is thicker at the top and thinner at the bottom.

[0012] Furthermore, a fixing device for limiting the displacement of the inner tube is provided above the sealing insert.

[0013] Furthermore, the outer wall of the inner tube is provided with a flow spoiler.

[0014] Furthermore, the contact is a conical contact, which includes an elastic sleeve, a positioning cone head is provided in the middle of the elastic sleeve, and the cone angle of the positioning cone head is not greater than the cone angle of the bottom of the conical sealing tube.

[0015] Furthermore, the side surface of the elastic sleeve is provided with more than two pressure relief grooves.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The freezing device can realize freezing in stages and sections by using the cooperation of the outer tube and the inner tube. It is not only simple in structure, but also effectively shortens the operation period, improves the operation efficiency and reduces the operation cost.

[0018] 2. The outer tube is set as a concentric reducer, so that when the freezing medium enters the conical sealed tube bottom of the outer tube from the inner tube and the medium channel, it gradually rises from the conical sealed tube bottom, and the concentric reducer is from thin to thick, so as to achieve the difference in freezing circle time, thereby better controlling the staged freezing effect of the formation.

[0019] 3. The setting of the internal threaded pipe and the threaded clamp makes it more convenient to replace the freezing area of ​​the device, and can flexibly realize segmented stratum freezing.

[0020] 4. The setting of the elastic sleeve and the positioning cone head ensures that the contact basically remains on the axis of the inner cavity of the outer tube when moving in the inner cavity of the outer tube, so that the position of the contact does not affect the freezing and coiling effect.

[0021] 5. The setting of the pressure relief groove can effectively reduce the resistance caused by the pressure change when the elastic sleeve moves back and forth in the inner cavity of the outer tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the freezing device of the present invention;

[0023] Figure 2 It is a schematic diagram of the contact structure of the present invention;

[0024] Figure 3 This is a schematic diagram of the connection between the inner tube and the contact of the present invention;

[0025] Figure 4 It is a schematic diagram of the internal connection structure of the present invention;

[0026] Explanation of the numbers in the figure: 1. outer tube, 11. medium outlet, 12. conical sealing tube bottom, 2. inner tube, 21. medium inlet, 22. spoiler, 3. sealing clamp, 31. sealing sleeve, 311. pipe opening, 32. sealing insert, 321. threaded clamp, 3211. through hole, 322. sealing plug, 4. contact, 41. elastic sleeve, 411. pressure relief groove, 42. positioning cone head, 5. medium channel, 6. fixing device. DETAILED DESCRIPTION

[0027] In order to better understand the purpose, structure and function of the present invention, the present invention is understood in conjunction with the accompanying drawings.

[0028] like Figure 1-4A ground freezing device is designed, comprising an outer tube 1 and an inner tube 2. The side wall of the outer tube 1 is penetrated with a medium outlet 11 for discharging a freezing medium, and the freezing medium can be low-temperature salt water. The lower end of the outer tube 1 is provided with a conical sealing tube bottom 12, and the bottom end of the conical seal 12 is welded to the outer tube with the same or similar material as the outer tube 1, and can be used on site only after passing the pressure test. The test pressure is twice the sum of the pressure difference between the liquid brine column in the outer tube and the clean water column outside the outer tube and the working pressure of the pump; the conical sealing tube bottom can be more conveniently placed in the freezing hole preset at the construction site, the upper end of the inner tube 2 is set as the medium inlet 21, the outer tube 1 is a concentric reducer, and the inner cavity of the outer tube 1 is provided with a sealing card 3, the sealing card 3 is placed above the medium outlet 11 to fix the outer wall of the inner tube 2, and the lower part of the inner tube 2 is vertically connected with a contact 4, and the contact and the inner tube can be evenly fixedly connected by welding or other means using materials such as steel bars, and a medium channel 5 is provided between the inner tube 2 and the contact 4 for the freezing medium to flow from the inner tube 2 to the outer tube 1.

[0029] Among them, the sealing card 3 includes a sealing sleeve 31 and a sealing insert 32. The sealing sleeve 31 is penetrated by a vertical pipe opening 311. The sealing sleeve can be made of rubber. The inner diameter of the pipe opening 311 is larger than the outer diameter of the inner tube 2. The sealing sleeve 31 is sealed to the inner wall of the outer tube 1, and the sealing insert 32 is sealed to clamp the outer wall of the inner tube 2 and the pipe opening 311.

[0030] When in use, the outer tube 1 is placed in the stratum to be frozen, and the inner tube 2 is set at a designated position in the outer tube 1 according to the operation requirements. The freezing medium, such as special low-temperature brine, enters the inner tube 2 from the medium inlet 21, and rises along the upper annular space of the conical sealed tube bottom 12 of the outer tube 1, and flows out from the medium outlet 11 to achieve freezing of the stratum above the conical bottom end of the outer tube 1; then the inner tube 2 is lifted, and the outer tube 1 and the inner tube 2 are further lowered to the next designated position, and the above steps are repeated to achieve segmented and phased freezing of the stratum.

[0031] In the above implementation, three embodiments are listed to implement the above technical solution:

[0032] Example 1

[0033] In this embodiment, the outer tube 1 is preferably a three-stage concentric reducer, and the through-tube opening 311 includes an internally threaded tube, which is a tapered internally threaded tube that is thick at the top and thin at the bottom. The sealing insert 32 includes a threaded clamp 321 and a sealing plug 322 that are matched with the internally threaded tube, the threaded clamp 321 is made of solid metal material, and the sealing plug 322 is made of rubber material, the threaded clamp 321 is penetrated by a through hole 3211, and the sealing plug 322 is sealed and fitted with the through hole 3211, and the through hole 3211 is a tapered hole that is thick at the top and thin at the bottom.

[0034] Example 2

[0035] The present embodiment is further designed on the basis of the embodiment 1. A clamping device 6 for limiting the displacement of the inner tube 2 is provided above the sealing insert 32. The clamping device 6 is preferably a clamp. The clamp tightens the inner tube 2, thereby limiting the upward and downward displacement of the inner tube 2. A spoiler component 22 is provided on the outer wall of the inner tube 2 below the sealing clamp 3. The spoiler component 22 is a wavy protrusion. When the freezing medium flows through the spoiler component 22, a spoiler effect will be generated, thereby increasing the contact area between the freezing medium and the inner wall of the outer tube 1, thereby enhancing the freezing effect.

[0036] Example 3

[0037] This embodiment is further designed on the basis of the embodiment 2, and the contact 4 is a conical contact. The conical contact includes an elastic sleeve 41, which is made of elastic material, such as rubber material, so that the elastic sleeve 41 has an elastic expansion function. When the elastic sleeve 41 enters the thin diameter from the thick diameter of the outer tube 1, the outer layer of the elastic sleeve 41 is squeezed by the inner wall of the concentric reducer and shrinks, and the elastic sleeve 41 is always in close contact with the inner wall of the outer tube 1. A positioning cone head 42 is provided in the middle of the elastic sleeve 41. The positioning cone head can be made of hard materials such as steel, and the cone angle of the positioning cone head 42 is not greater than the cone angle of the conical sealing tube bottom 12. Four pressure relief grooves 411 are provided on the side of the elastic sleeve 41, so that when the inner tube 2 is lowered, the liquid and gas at the bottom of the contact 4 enter the outer tube 1 through the pressure relief grooves 411, reducing the resistance during lowering.

[0038] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A ground freezing device, comprising an outer tube (1) and an inner tube (2), wherein a medium outlet (11) is provided through the side wall of the outer tube (1), a conical sealing tube bottom (12) is provided at the lower end of the outer tube (1), and a medium inlet (21) is provided at the upper end of the inner tube (2), characterized in that: The outer tube (1) is a concentric reducer tube. The inner cavity of the outer tube (1) is provided with a sealing clamp (3). The sealing clamp (3) is placed above the medium outlet (11) to fix the outer wall of the inner tube (2). The lower part of the inner tube (2) is vertically connected to a contact (4). A medium channel (5) is provided between the inner tube (2) and the contact (4). The sealing clamp (3) comprises a sealing sleeve (31) and a sealing insert (32). The sealing sleeve (31) is provided with a vertical pipe opening (311) through it. The inner diameter of the pipe opening (311) is larger than the outer diameter of the inner tube (2). The sealing sleeve (31) is in sealing contact with the inner wall of the outer tube (1). The sealing insert (32) is sealed. The outer wall of the clamped inner tube (2) is sealed and fitted with the through-tube opening (311); the sealing insert (32) comprises a threaded clamp (321) and a sealing plug (322) for use with the inner threaded tube; the threaded clamp (321) is provided with a through hole (3211) extending therethrough; the sealing plug (322) is sealed and fitted with the through hole (3211); the contact (4) is a conical contact, comprising an elastic sleeve (41); a positioning cone head (42) is provided in the middle of the elastic sleeve (41); the cone angle of the positioning cone head (42) is not greater than the cone angle of the bottom (12) of the conical sealing tube; and two or more pressure relief grooves (411) are provided on the side of the elastic sleeve (41).

2. A ground freezing device according to claim 1, characterized in that The through pipe opening (311) comprises an internally threaded pipe.

3. A ground freezing device according to claim 2, characterized in that The internal threaded tube is a tapered internal threaded tube that is thick at the top and thin at the bottom.

4. A ground freezing device according to claim 1, characterized in that The through hole (3211) is a tapered hole that is thick at the top and thin at the bottom.

5. A ground freezing device according to claim 1, characterized in that A fixing device (6) for limiting the displacement of the inner tube (2) is provided above the sealing insert (32).

6. A ground freezing device according to claim 1, characterized in that The outer wall of the inner tube (2) is provided with a flow-disturbing component (22).

Images