Steam heat preservation pipe and process system for injecting foaming polyurethane between steam inner pipe and steam outer pipe of steam heat preservation pipe

Abstract

The invention discloses a steam thermal insulation pipe which comprises a steam inner pipe, an inner-layer thermal insulation sleeve and an outer pipe, the steam inner pipe is coaxially sleeved with the inner-layer thermal insulation sleeve, and the space between the inner-layer thermal insulation sleeve and the outer pipe is filled with polyurethane foaming materials, so that a polyurethane foaming thermal insulation layer is formed between the inner-layer thermal insulation sleeve and the outer pipe; a plurality of temperature locking separation supporting rings distributed at equal intervals are coaxially arranged in the polyurethane foaming heat preservation layer, the temperature locking separation supporting rings are coaxially supported between the inner-layer heat preservation sleeve and the outer pipe, and the polyurethane foaming heat preservation layer is divided into a plurality of independent sections of foaming polyurethane heat preservation layers through the temperature locking separation supporting rings. And the problem of large-volume holes is avoided through step-by-step filling.

Description

Technical Field

[0001] The invention belongs to the technical field of steam insulation pipes. Background Art

[0002] In order to improve the thermal insulation performance, foamed polyurethane needs to be filled between the inner and outer tubes of the steam insulation pipe. Since the foamed polyurethane filling cavity between the inner insulation sleeve and the outer tube is a narrow and long structure, the filling uniformity of the foaming structure after infusion cannot be guaranteed. After the infusion is completed, large-volume voids are likely to form in the polyurethane foam insulation layer, affecting the thermal insulation performance. Summary of the invention

[0003] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a process system for injecting foamed polyurethane into a steam insulation pipe and between the inner and outer steam pipes thereof, which avoids the problem of large-volume cavities by filling in stages.

[0004] Technical solution: To achieve the above-mentioned purpose, the steam insulation pipe of the present invention comprises a steam inner pipe, an inner insulation sleeve and an outer pipe. The inner insulation sleeve is coaxially sleeved outside the steam inner pipe, and polyurethane foam material is filled between the inner insulation sleeve and the outer pipe, thereby forming a polyurethane foam insulation layer between the inner insulation sleeve and the outer pipe.

[0005] Furthermore, a number of equidistantly distributed temperature-locking separation support rings are coaxially arranged in the polyurethane foam insulation layer, each temperature-locking separation support ring is coaxially supported between the inner insulation sleeve and the outer tube, and the number of temperature-locking separation support rings divides the polyurethane foam insulation layer into a number of mutually independent multi-section foamed polyurethane insulation layers.

[0006] Furthermore, an annular flange is provided on one side of the inner ring of each temperature-locking separation support ring, and a plurality of spray rod passing holes are hollowed out in a circular array on the temperature-locking separation support ring.

[0007] Furthermore, the temperature-locking separation support ring is made of hard foam plastic.

[0008] Furthermore, a foamed polyurethane process system is injected between the steam inner and outer pipes of the steam insulation pipe:

[0009] S1, prepare a steam inner pipe with an inner insulation sleeve, an outer pipe, a left temporary end cover, a right temporary end cover, a polyurethane foaming injection machine and a pipe body clamp;

[0010] S2, the steam inner pipe which has been covered with the inner insulation sleeve is coaxially extended into the outer pipe, so that a ring-shaped foamed polyurethane filling cavity is formed between the inner insulation sleeve and the outer pipe, and then the steam inner pipe and the outer pipe are fixedly clamped by a pipe body clamp respectively;

[0011] S3, sealing the two ends of the foamed polyurethane filling cavity between the inner insulation sleeve and the outer tube with a left temporary end cover and a right temporary end cover respectively;

[0012] S4, a foamed polyurethane infusion hole connected to the foamed polyurethane filling cavity is opened on the wall of the outer tube away from the right temporary end cover, and an exhaust hole connected to the foamed polyurethane filling cavity is also opened on the right temporary end cover;

[0013] S5, the polyurethane foaming injection machine aims the polyurethane foaming spray gun at the polyurethane foaming injection hole, quickly injects the polyurethane foaming into the polyurethane foaming filling cavity between the inner insulation sleeve and the outer tube through the polyurethane foaming injection hole and rapidly foams and expands until the polyurethane foaming filling cavity between the inner insulation sleeve and the outer tube is completely filled with the polyurethane foaming and a polyurethane foaming insulation layer is formed;

[0014] S6, remove the left temporary end cover and the right temporary end cover to obtain the target insulation pipe.

[0015] Furthermore, a foamed polyurethane process system is injected between the steam inner and outer pipes of the steam insulation pipe:

[0016] Prepare an inner steam pipe with an inner insulation sleeve, an outer steam pipe, a temporary left end cover, a pipe body clamp, several temperature-locking separation support rings, a polyurethane foaming machine and a probe-type polyurethane foaming injector.

[0017] The probe-type foaming polyurethane injector includes a linear displacement arm, a displacement device can drive the linear displacement arm to displace along the length direction, an annular spray gun bracket is fixedly installed at the end of the linear displacement arm, the axis of the annular spray gun bracket is parallel to the linear displacement arm, and a plurality of polyurethane foaming spray guns are fixedly installed in a circular array on the side of the annular spray gun bracket away from the linear displacement arm; the foaming polyurethane outlet end of the polyurethane foaming machine is connected to the inlet end of each polyurethane foaming spray gun through a delivery pipe on the linear displacement arm; the injection rod of each polyurethane foaming spray gun is parallel to the axis of the annular spray gun bracket, and the end of each injection rod is a foaming polyurethane nozzle; a plurality of telescopic devices parallel to the injection rod are fixedly installed in a circular array on the outer circumference of the annular spray gun bracket; the inner and outer diameters of the annular spray gun bracket are both between the outer diameter of the inner insulation casing and the inner diameter of the outer tube; the plurality of injection rods distributed in a circular array can pass through the plurality of injection rod through holes distributed in a circular array on the temperature locking separation support ring one by one.

[0018] Further:

[0019] SS1, the steam inner pipe with the inner insulation sleeve coaxially extends into the outer pipe;

[0020] SS2, seal the left end of the foamed polyurethane filling cavity between the inner insulation sleeve and the outer tube with the left temporary end cover;

[0021] SS3, a plurality of coaxially stacked temperature-locking partition support rings are coaxially installed on the side of the probe-type foaming polyurethane ejector away from the linear displacement arm.

[0022] SS4, the linear displacement arm drives the immersion foam polyurethane injector with several temperature-locking separation support rings installed coaxially, gradually extending coaxially from the right to the left into the annular columnar foam polyurethane filling cavity between the inner insulation sleeve and the outer tube, until the annular flange on the first temperature-locking separation support ring contacts the left temporary end cover.

[0023] SS5, the foaming polyurethane nozzle sprays foaming polyurethane evenly into the first annular bin to be filled, and the linear displacement arm is controlled to drive the immersion foaming polyurethane injector to slowly move to the right. The first temperature-locking separation support ring moves slowly to the right to the target position following the immersion foaming polyurethane injector, thus forming the first section of foaming polyurethane insulation layer.

[0024] SS6, while the linear displacement arm drives the immersion foaming polyurethane injector to gradually move to the right, the telescopic rod ends of each telescopic device gradually extend, so that several temperature-locking separation support rings remain stationary, and the immersion foaming polyurethane injector as a whole moves to the right individually, until the foaming polyurethane nozzle moves to the right to the second annular bin to be filled that is connected between the first temperature-locking separation support ring and the second temperature-locking separation support ring. At this time, the foaming polyurethane nozzles at the ends of several injection rods are controlled to evenly spray foaming polyurethane into the second annular bin to be filled, and the linear displacement arm is controlled to drive the immersion foaming polyurethane injector to slowly move to the right, until the second temperature-locking separation support ring follows the immersion foaming polyurethane injector to slowly move to the right to the target position, thereby forming the second section of foaming polyurethane insulation layer.

[0025] SS7, continuously repeat the process of "SS6" until the foamed polyurethane filling chamber between the inner insulation sleeve and the outer tube is gradually filled from left to right with several sections of independent multi-section foamed polyurethane insulation layers that are more dense and uniform, and several equidistantly distributed temperature-locking separation support rings are coaxially supported between the inner insulation sleeve and the outer tube, and the temperature-locking separation support rings separate the polyurethane foam insulation layer into several independent multi-section foamed polyurethane insulation layers.

[0026] SS8, remove the left temporary end cover.

[0027] Beneficial effect: The foamed polyurethane filling chamber between the inner insulation sleeve and the outer tube of Example 2 of the present invention is filled with several independent multi-segment foamed polyurethane insulation layers from left to right in a more dense and uniform manner step by step, and several equidistantly distributed temperature-locking separation support rings are coaxially supported between the inner insulation sleeve and the outer tube, and the several temperature-locking separation support rings separate the polyurethane foam insulation layer into several independent multi-segment foamed polyurethane insulation layers to avoid the formation of voids, thereby achieving the effect of separation and temperature locking, and the several temperature-locking separation support rings also play a supporting role between the steam inner tube and the outer tube of the target insulation tube to prevent the problem of coaxial deviation during later use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of a first embodiment of a steam insulation pipe;

[0029] Figure 2 It is a schematic diagram of a second embodiment of a steam insulation pipe;

[0030] Figure 3 It is a schematic diagram of the process of injecting foamed polyurethane between the steam inner and outer pipes of the first embodiment at the end of the "S4" process;

[0031] Figure 4 This is a schematic diagram of the state at the end of the "SS2" process of injecting foamed polyurethane between the steam inner and outer pipes of the second embodiment;

[0032] Figure 5 for Figure 4 A cross-sectional view of

[0033] Figure 6 It is a schematic diagram of the installation and disassembly of the immersion type foaming polyurethane injector and several temperature locking separation support rings thereof;

[0034] Figure 7 This is a schematic diagram of the state at the end of the "SS4" process of injecting foamed polyurethane between the steam inner and outer pipes of the second embodiment. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings.

[0036] like Figure 1 The "first embodiment" of the steam insulation pipe shown includes a steam inner pipe 4, an inner insulation sleeve 1 and an outer pipe 2. The inner insulation sleeve 1 is coaxially sleeved outside the steam inner pipe 4. Polyurethane foam material is filled between the inner insulation sleeve 1 and the outer pipe 2, so that a polyurethane foam insulation layer 3 is formed between the inner insulation sleeve 1 and the outer pipe 2.

[0037] The process system of injecting foamed polyurethane between the inner and outer steam pipes of the steam insulation pipe of the "first embodiment":

[0038] S1, prepare a steam inner pipe 4 with an inner insulation sleeve 1 on the outside, an outer pipe 2, a left temporary end cover 7, a right temporary end cover 18, a polyurethane foaming injection machine and a pipe body fixture;

[0039] S2, the steam inner tube 4 which has been covered with the inner insulation sleeve 1 is coaxially extended into the outer tube 2, so that a ring-shaped foamed polyurethane filling cavity is formed between the inner insulation sleeve 1 and the outer tube 2, and then the steam inner tube 4 and the outer tube 2 are fixedly clamped by a tube body clamp respectively;

[0040] S3, respectively seal the two ends of the foamed polyurethane filling cavity between the inner insulation sleeve 1 and the outer tube 2 with the left temporary end cover 7 and the right temporary end cover 18;

[0041] S4, a polyurethane foaming hole 20 connected to the polyurethane foaming cavity is opened on the wall of the outer tube 2 away from the right temporary end cover 18, and a vent hole 19 connected to the polyurethane foaming cavity is opened on the right temporary end cover 18. Figure 3 As shown;

[0042] S5, the polyurethane foaming injection machine aims the polyurethane foaming spray gun at the polyurethane foaming injection hole 20, quickly injects the polyurethane foaming into the polyurethane foaming filling cavity between the inner insulation sleeve 1 and the outer tube 2 through the polyurethane foaming injection hole 20 and rapidly foams and expands until the polyurethane foaming filling cavity between the inner insulation sleeve 1 and the outer tube 2 is completely filled with the polyurethane foaming, and a polyurethane foaming insulation layer 3 is formed;

[0043] S6, dismantle the left temporary end cover 7 and the right temporary end cover 18 to obtain the target insulation pipe.

[0044] Although the above process has the characteristics of quick operation and simple structure, it has the following disadvantages:

[0045] 1. Since the outer tube 2 is a non-transparent structure, it is impossible to know whether the foamed polyurethane filling cavity between the inner insulation sleeve 1 and the outer tube 2 is completely filled during the "S5" process;

[0046] 2. The steam inner tube 4 and the outer tube 2 are supported only by foamed polyurethane, and the coaxiality is unstable during later use and is prone to deviation.

[0047] 3. Since the foamed polyurethane filling cavity between the inner insulation sleeve 1 and the outer tube 2 is a narrow and long structure, the filling uniformity of the foamed structure after infusion cannot be guaranteed. After the infusion is completed, large-volume cavities 21 are likely to be formed in the polyurethane foam insulation layer 3, affecting the insulation performance.

[0048] The second embodiment improved on the basis of the first embodiment:

[0049] like Figure 2 The polyurethane foam insulation layer 3 shown is coaxially provided with a number of equidistantly distributed temperature-locking separation support rings 8, each temperature-locking separation support ring 8 is coaxially supported between the inner insulation sleeve 1 and the outer tube 2, and the temperature-locking separation support rings 8 separate the polyurethane foam insulation layer 3 into a number of mutually independent multi-segment foamed polyurethane insulation layers 3a, thereby achieving the effect of separation and temperature locking, and the temperature-locking separation support rings 8 also play a supporting role between the steam inner tube 4 and the outer tube 2 of the target insulation pipe, preventing the problem of coaxial deviation during later use; an annular flange 17 is provided on one side of the inner circle of each temperature-locking separation support ring 8, and a number of spray rod through holes 22 are hollowed out in a circular array on the temperature-locking separation support ring 8; the temperature-locking separation support ring 8 is made of hard foam plastic, so that the temperature-locking separation support ring 8 has a supporting function while reducing its own thermal conductivity efficiency to avoid forming a "thermal bridge" itself.

[0050] The process system for injecting foamed polyurethane between the steam inner and outer pipes of the steam insulation pipe of the "Second Embodiment" includes an inner steam pipe 4 with an inner insulation sleeve 1 on the outside, an outer pipe 2, a left temporary end cover 7, a pipe body clamp, a plurality of temperature-locking separation support rings 8, a polyurethane foaming machine and a probe-type foamed polyurethane injector 6.

[0051] like Figure 6 and 7 As shown, the immersion type foaming polyurethane injector 6 includes a linear displacement arm 5, a displacement device can drive the linear displacement arm 5 to move along the length direction, an annular spray gun bracket 10 is fixedly installed at the end of the linear displacement arm 5, the axis of the annular spray gun bracket 10 is parallel to the linear displacement arm 5, and a plurality of polyurethane foaming spray guns 9 are fixedly installed in a circular array on the side of the annular spray gun bracket 10 away from the linear displacement arm 5; the foaming polyurethane outlet end of the polyurethane foaming machine is connected to the inlet end of each polyurethane foaming spray gun 9 through the delivery pipe 31 on the linear displacement arm 5. ; The spray rod 13 of each polyurethane foaming spray gun 9 is parallel to the axis of the annular spray gun bracket 10, and the end of each spray rod 13 is a foaming polyurethane nozzle 14; the outer circumference of the annular spray gun bracket 10 is fixedly installed with a plurality of telescoping devices 11 parallel to the spray rod 13 in a circular array; the inner and outer diameters of the annular spray gun bracket 10 are both between the outer diameter of the inner insulation sleeve 1 and the inner diameter of the outer tube 2; the plurality of spray rods 13 distributed in a circular array can pass through the plurality of spray rod through holes 22 distributed in a circular array on the temperature locking separation support ring 8 one by one.

[0052] The specific process includes the following:

[0053] SS1, the steam inner tube 4 which has been covered with the inner insulation sleeve 1 is coaxially extended into the outer tube 2, so that a ring-shaped foamed polyurethane filling cavity is formed between the inner insulation sleeve 1 and the outer tube 2, and then the steam inner tube 4 and the outer tube 2 are fixed and clamped respectively by the tube body clamp;

[0054] SS2, seal the left end of the foamed polyurethane filling cavity between the inner insulation sleeve 1 and the outer tube 2 with the left temporary end cover 7; and make the probe foamed polyurethane injector 6 coaxial with the side of the steam inner tube 4 away from the left temporary end cover 7, such as Figure 4 ;

[0055] SS3, a plurality of coaxially stacked temperature-locking separation support rings 8 are coaxially installed on the side of the probe-type foaming polyurethane injector 6 away from the linear displacement arm 5;

[0056] In the installed state: the plurality of spray rods 13 distributed in a circular array on the probe-type foaming polyurethane injector 6 pass through the plurality of spray rod through holes 22 on the plurality of stacked temperature-locking partition support rings 8 in a one-to-one correspondence; the annular flange 17 on each temperature-locking partition support ring 8 is located on the side away from the annular spray gun bracket 10; the one of the plurality of temperature-locking partition support rings 8 farthest from the annular spray gun bracket 10 is recorded as the first temperature-locking partition support ring 8a; the one of the plurality of temperature-locking partition support rings 8 closest to the annular spray gun bracket 10 is recorded as the tail temperature-locking partition support ring 8b; the ends of the telescopic rods 12 of each telescope 11 are limitedly contacted with the side of the tail temperature-locking partition support ring 8b close to the annular spray gun bracket 10, and the foaming polyurethane nozzles 14 at the ends of each spray rod 13 protrude from the side of the first temperature-locking partition support ring 8a away from the annular spray gun bracket 10;

[0057] SS4, the linear displacement arm 5 drives the immersion foaming polyurethane injector 6 on which several temperature-locking separation support rings 8 are coaxially installed, and gradually coaxially extends from the right to the left into the annular columnar foaming polyurethane filling cavity between the inner insulation sleeve 1 and the outer tube 2, so that the first temperature-locking separation support ring 8a among the several temperature-locking separation support rings 8 gradually approaches the left temporary end cover 7, until the annular flange 17 on the first temperature-locking separation support ring 8a contacts the left temporary end cover 7, at this time, the first annular bin 15a to be filled is formed between the first temperature-locking separation support ring 8a and the left temporary end cover 7, at this time, the foaming polyurethane nozzle 14 at the end of each injection rod 13 extends into the first annular bin 15a to be filled, because each temperature-locking separation support ring 8 has an annular flange 17, so at this time, a circle of annular bins 15 to be filled are formed between any two adjacent temperature-locking separation support rings 8, at this time, as Figure 7 shown.

[0058] SS5, controls the foaming polyurethane nozzles 14 at the ends of the plurality of spray rods 13 to uniformly spray the foaming polyurethane into the first annular bin 15a to be filled. While the foaming polyurethane is continuously sprayed into the first annular bin 15a to be filled, the sprayed foaming polyurethane itself rapidly expands under the action of the foaming reaction, so that the first annular bin 15a to be filled is rapidly filled with the foaming polyurethane. At this time, the linear displacement arm 5 is controlled to drive the immersion foaming polyurethane injector 6 to slowly move to the right. At the same time, the volume of the first annular bin 15a to be filled increases with the foaming polyurethane inside. The first temperature-locking separation support ring 8a and several temperature-locking separation support rings 8 on the right side of the first temperature-locking separation support ring 8a are synchronously displaced to the right by the immersion type foaming polyurethane injector 6 under the strong rightward thrust of the foaming polyurethane gradually expanding in the first annular bin 15a to be filled, until the first temperature-locking separation support ring 8a slowly displaces to the right to the target position along with the immersion type foaming polyurethane injector 6, thereby forming the first section of the foaming polyurethane insulation layer 3a; the spraying of the foaming polyurethane nozzle 14 is paused.

[0059] SS6, controls the linear displacement arm 5 to drive the immersion foaming polyurethane injector 6 to gradually move to the right, while the ends of the telescopic rods 12 of each telescopic device 11 gradually extend, so that the plurality of temperature-locking partition support rings 8 remain stationary, and the immersion foaming polyurethane injector 6 moves to the right as a whole, until the foaming polyurethane nozzle 14 moves to the right to the second annular bin 15 to be filled that is connected between the first temperature-locking partition support ring 8a and the second temperature-locking partition support ring 8. At this time, the foaming polyurethane nozzles 14 at the ends of the plurality of injection rods 13 are controlled to uniformly spray foaming polyurethane into the second annular bin 15 to be filled. While the second annular bin 15 to be filled is continuously sprayed with foaming polyurethane, the sprayed foaming polyurethane itself expands rapidly under the action of the foaming reaction, thereby making the second annular bin 15 to be filled. The filling bin 15 is quickly filled with foamed polyurethane. At this time, the linear displacement arm 5 is controlled to drive the immersion foamed polyurethane injector 6 to slowly move to the right. At the same time, the volume of the second annular bin 15 to be filled gradually increases with the continuous replenishment of the foamed polyurethane inside and the foaming reaction. The second temperature-locking separation support ring 8 and several temperature-locking separation support rings 8 on the right side of the second temperature-locking separation support ring 8 move to the right synchronously with the immersion foamed polyurethane injector 6 under the strong rightward thrust of the gradually expanding foamed polyurethane in the second annular bin 15 to be filled, until the second temperature-locking separation support ring 8 moves slowly to the right to the target position with the immersion foamed polyurethane injector 6, thereby forming the second section of the foamed polyurethane insulation layer 3a; the spraying of the foamed polyurethane nozzle 14 is paused.

[0060] SS7, continuously cycle the process of "SS6" until the foamed polyurethane filling chamber between the inner insulation sleeve 1 and the outer tube 2 is filled step by step from left to right with several sections of independent multi-section foamed polyurethane insulation layers 3a that are denser and more uniform, avoiding the formation of voids, and several equidistantly distributed temperature-locking separation support rings 8 are coaxially supported between the inner insulation sleeve 1 and the outer tube 2, and the temperature-locking separation support rings 8 separate the polyurethane foam insulation layer 3 into several independent multi-section foamed polyurethane insulation layers 3a, thereby achieving the effect of separation and temperature locking, and the temperature-locking separation support rings 8 also play a supporting role between the steam inner tube 4 and the outer tube 2 of the target insulation tube, preventing the problem of coaxial deviation during later use.

[0061] SS8, remove the left temporary end cover 7 and obtain the target insulation pipe.

[0062] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Steam insulation pipe, characterized in that: The invention comprises a steam inner tube (4), an inner thermal insulation sleeve (1) and an outer tube (2); the inner thermal insulation sleeve (1) is coaxially sleeved outside the steam inner tube (4); a polyurethane foam material is filled between the inner thermal insulation sleeve (1) and the outer tube (2), so that a polyurethane foam insulation layer (3) is formed between the inner thermal insulation sleeve (1) and the outer tube (2).

2. The steam insulation pipe according to claim 1, characterized in that: A plurality of equally spaced temperature-locking separation support rings (8) are coaxially arranged in the polyurethane foam insulation layer (3); each of the temperature-locking separation support rings (8) is coaxially supported between the inner insulation sleeve (1) and the outer tube (2); and the plurality of temperature-locking separation support rings (8) separate the polyurethane foam insulation layer (3) into a plurality of mutually independent multi-stage polyurethane foam insulation layers (3a).

3. The steam insulation pipe according to claim 3, characterized in that: An annular flange (17) is provided on one side of the inner ring of each temperature-locking separation support ring (8), and a plurality of spray rod through holes (22) are hollowed out in a circumferential array on the temperature-locking separation support ring (8).

4. The steam insulation pipe according to claim 3, characterized in that: The temperature-locking separation support ring (8) is made of hard foam plastic.

5. The process system for injecting foamed polyurethane between the inner and outer steam pipes of the steam insulation pipe according to claim 1, characterized in that: S1, prepare an inner steam pipe (4) with an inner insulation sleeve (1) on the outside, an outer pipe (2), a left temporary end cover (7), a right temporary end cover (18), a polyurethane foaming injection machine and a pipe body clamp; S2, the steam inner tube (4) which has been covered with the inner insulation sleeve (1) is coaxially extended into the outer tube (2) so that a ring-shaped foamed polyurethane filling cavity is formed between the inner insulation sleeve (1) and the outer tube (2), and then the steam inner tube (4) and the outer tube (2) are fixedly clamped by a tube body clamp; S3, respectively sealing the two ends of the foamed polyurethane filling cavity between the inner thermal insulation sleeve (1) and the outer tube (2) with a left temporary end cover (7) and a right temporary end cover (18); S4, a foamed polyurethane infusion hole (20) communicating with the foamed polyurethane filling cavity is formed on the wall of the outer tube (2) at one end away from the right temporary end cover (18), and a vent hole (19) communicating with the foamed polyurethane filling cavity is also formed on the right temporary end cover (18); S5, the polyurethane foaming injection machine directs the polyurethane foaming spray gun toward the polyurethane foaming injection hole (20), rapidly injects the polyurethane foaming into the polyurethane foaming filling cavity between the inner thermal insulation sleeve (1) and the outer tube (2) through the polyurethane foaming injection hole (20), and rapidly foams and expands the polyurethane foaming filling cavity between the inner thermal insulation sleeve (1) and the outer tube (2), until the polyurethane foaming filling cavity between the inner thermal insulation sleeve (1) and the outer tube (2) is completely filled with the polyurethane foaming, and the polyurethane foaming thermal insulation layer (3) is formed; S6, dismantle the left temporary end cover (7) and the right temporary end cover (18) to obtain the target insulation pipe.

6. The process system for injecting foamed polyurethane between the inner and outer steam pipes of the steam insulation pipe according to claim 3, characterized in that: Prepare a steam inner pipe (4) with an inner layer of thermal insulation sleeve (1) on the outside, an outer pipe (2), a left temporary end cover (7), a pipe body clamp, a plurality of temperature-locking partition support rings (8), a polyurethane foaming machine and a probe-type foaming polyurethane injector (6).

7. According to the process system for injecting foamed polyurethane between the steam inner and outer pipes of the steam insulation pipe as described in claim 6, the immersion-type foamed polyurethane injector (6) includes a linear displacement arm (5), the displacement device can drive the linear displacement arm (5) to displace along the length direction, and an annular spray gun bracket (10) is fixedly installed at the end of the linear displacement arm (5), the axis of the annular spray gun bracket (10) is parallel to the linear displacement arm (5), and a plurality of polyurethane foaming spray guns (9) are fixedly installed in a circular array on one side of the annular spray gun bracket (10) away from the linear displacement arm (5); the foamed polyurethane outlet end of the polyurethane foaming machine passes through the delivery pipe (31) on the linear displacement arm (5) The inlet ends of the polyurethane foaming spray guns (9) are connected; the spray rods (13) of the polyurethane foaming spray guns (9) are parallel to the axis of the annular spray gun bracket (10), and the end of each spray rod (13) is a foaming polyurethane nozzle (14); a plurality of telescopic devices (11) parallel to the spray rods (13) are fixedly installed in a circumferential array on the outer circumference of the annular spray gun bracket (10); the inner and outer diameters of the annular spray gun bracket (10) are between the outer diameter of the inner layer insulation sleeve (1) and the inner diameter of the outer tube (2); the plurality of spray rods (13) distributed in a circumferential array can pass through the plurality of spray rod through holes (22) distributed in a circumferential array on the temperature locking separation support ring (8) in a one-to-one correspondence.

8. The process system for injecting foamed polyurethane between the inner and outer steam pipes of the steam insulation pipe according to claim 7, characterized in that: SS1, a steam inner pipe (4) covered with an inner thermal insulation sleeve (1) coaxially extends into the outer pipe (2); SS2, seal the left end of the foamed polyurethane filling cavity between the inner thermal insulation sleeve (1) and the outer tube (2) with a left temporary end cover (7); SS3, coaxially installing a plurality of temperature-locking separation support rings (8) coaxially stacked on a side of the probe-type foaming polyurethane ejector (6) away from the linear displacement arm (5); SS4, the linear displacement arm (5) drives the immersion-type foamed polyurethane injector (6) coaxially mounted with a plurality of temperature-locking separation support rings (8) to gradually coaxially extend from the right side to the left side into the annular columnar foamed polyurethane filling cavity between the inner insulation sleeve (1) and the outer tube (2) until the annular flange (17) on the first temperature-locking separation support ring (8a) contacts the left temporary end cover (7) in a limited manner; SS5, the foaming polyurethane nozzle (14) uniformly sprays the foaming polyurethane into the first annular filling bin (15a), controls the linear displacement arm (5) to drive the immersion foaming polyurethane injector (6) to slowly move to the right, and the first temperature-locking separation support ring (8a) moves slowly to the right to the target position following the immersion foaming polyurethane injector (6), thereby forming the first section of the foaming polyurethane insulation layer (3a); SS6, the linear displacement arm (5) drives the immersion foaming polyurethane injector (6) to gradually move to the right, while the ends of the telescopic rods (12) of the telescopic devices (11) gradually extend, so that the plurality of temperature-locking separation support rings (8) remain stationary, while the immersion foaming polyurethane injector (6) moves to the right as a whole, until the foaming polyurethane nozzle (14) moves to the right to the second annular bin (15) connecting the first temperature-locking separation support ring (8a) and the second temperature-locking separation support ring (8), at which time the foaming polyurethane nozzles (14) at the ends of the plurality of spray rods (13) are controlled to uniformly spray foaming polyurethane into the second annular bin (15), and the linear displacement arm (5) is controlled to drive the immersion foaming polyurethane injector (6) to slowly move to the right, until the second temperature-locking separation support ring (8) moves to the target position along with the immersion foaming polyurethane injector (6), thereby forming a second section of the foaming polyurethane thermal insulation layer (3a); SS7, the process of "SS6" is continuously repeated until the polyurethane foam filling chamber between the inner thermal insulation sleeve (1) and the outer tube (2) is gradually filled from left to right with a plurality of independent multi-stage polyurethane foam insulation layers (3a) that are more dense and uniform, and a plurality of equally spaced temperature-locking separation support rings (8) are coaxially supported between the inner thermal insulation sleeve (1) and the outer tube (2), and the plurality of temperature-locking separation support rings (8) separate the polyurethane foam insulation layer (3) into a plurality of independent multi-stage polyurethane foam insulation layers (3a); SS8, remove the left temporary end cover (7).

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