CN112428504A - Prefabricated heat preservation pipe injection process and heat preservation pipe - Google Patents
Prefabricated heat preservation pipe injection process and heat preservation pipe Download PDFInfo
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- CN112428504A CN112428504A CN202011139450.0A CN202011139450A CN112428504A CN 112428504 A CN112428504 A CN 112428504A CN 202011139450 A CN202011139450 A CN 202011139450A CN 112428504 A CN112428504 A CN 112428504A
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- 238000002347 injection Methods 0.000 title claims abstract description 82
- 239000007924 injection Substances 0.000 title claims abstract description 82
- 238000000034 method Methods 0.000 title claims abstract description 39
- 238000004321 preservation Methods 0.000 title claims description 12
- 229920002635 polyurethane Polymers 0.000 claims abstract description 72
- 239000004814 polyurethane Substances 0.000 claims abstract description 72
- 239000000463 material Substances 0.000 claims abstract description 58
- 238000005187 foaming Methods 0.000 claims abstract description 46
- 239000004698 Polyethylene Substances 0.000 claims abstract description 41
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 41
- -1 polyethylene Polymers 0.000 claims abstract description 41
- 229920000573 polyethylene Polymers 0.000 claims abstract description 41
- 239000010959 steel Substances 0.000 claims abstract description 41
- 229920005830 Polyurethane Foam Polymers 0.000 claims abstract description 8
- 239000011496 polyurethane foam Substances 0.000 claims abstract description 8
- 238000005422 blasting Methods 0.000 claims abstract description 5
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000000047 product Substances 0.000 claims description 23
- 238000009413 insulation Methods 0.000 claims description 20
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- 238000000465 moulding Methods 0.000 claims description 6
- 230000000903 blocking effect Effects 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 3
- 238000003851 corona treatment Methods 0.000 claims description 3
- 238000005520 cutting process Methods 0.000 claims description 3
- 238000001125 extrusion Methods 0.000 claims description 3
- 238000007689 inspection Methods 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 230000000149 penetrating effect Effects 0.000 claims description 3
- 229920003023 plastic Polymers 0.000 claims description 3
- 239000004033 plastic Substances 0.000 claims description 3
- 239000011265 semifinished product Substances 0.000 claims description 3
- 238000004513 sizing Methods 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims 1
- 238000005507 spraying Methods 0.000 claims 1
- 230000000694 effects Effects 0.000 abstract description 3
- 238000012360 testing method Methods 0.000 description 15
- 238000001514 detection method Methods 0.000 description 5
- 238000009827 uniform distribution Methods 0.000 description 3
- 238000009826 distribution Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 239000006260 foam Substances 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 238000003892 spreading Methods 0.000 description 2
- 239000004721 Polyphenylene oxide Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- 150000002513 isocyanates Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 229920000570 polyether Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
- B29C44/02—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles
- B29C44/12—Incorporating or moulding on preformed parts, e.g. inserts or reinforcements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
- B29C44/34—Auxiliary operations
- B29C44/36—Feeding the material to be shaped
- B29C44/38—Feeding the material to be shaped into a closed space, i.e. to make articles of definite length
- B29C44/42—Feeding the material to be shaped into a closed space, i.e. to make articles of definite length using pressure difference, e.g. by injection or by vacuum
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L59/00—Thermal insulation in general
- F16L59/02—Shape or form of insulating materials, with or without coverings integral with the insulating materials
- F16L59/028—Compositions for or methods of fixing a thermally insulating material
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L9/00—Rigid pipes
- F16L9/14—Compound tubes, i.e. made of materials not wholly covered by any one of the preceding groups
- F16L9/147—Compound tubes, i.e. made of materials not wholly covered by any one of the preceding groups comprising only layers of metal and plastics with or without reinforcement
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2075/00—Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Thermal Insulation (AREA)
Abstract
The invention provides a prefabricated heat-insulating pipe injection process which sequentially comprises the steps of producing a polyethylene outer pipe, performing shot blasting and rust removal on a steel pipe, plugging a sleeve, injecting a polyurethane foam material, foaming, detecting quality and warehousing a finished product; the steps of injecting the polyurethane foam material are as follows: fixing the pipe fitting after the sleeve pipe is plugged on an inclined foaming platform, adjusting the angle of the pipe fitting through the inclined foaming platform to enable the pipe fitting to form an inclination angle of 2-6 degrees with the horizontal direction, and then inserting an injection gun head of a foaming machine into an injection port for injecting materials; and after the material injection is finished, the pipe fitting is adjusted to the horizontal position by inclining the foaming platform. The heat-insulating pipe prepared by the injection process has the advantages that the pipeline is complete and attractive, the density of the polyurethane heat-insulating layer in the pipe is uniform, and the heat-insulating effect of each position of the heat-insulating pipe is consistent; the pipe fitting keeps an inclination angle of 2-6 degrees for inclined injection, and the plugging flange at the inclined high end is provided with an exhaust port which can discharge bubbles and gas in the pipe in time.
Description
Technical Field
The invention belongs to the technical field of preparation of insulating pipes, and particularly relates to an insulating pipe injection process and an insulating pipe.
Background
When the insulating tube is produced, the insulating material needs to be injected into the interior, but when the existing insulating tube is produced by injection, most of the existing insulating tube is provided with an injection hole in the middle position of the insulating tube, the injection is carried out under the horizontal condition, the pipeline is easy to damage by the injection mode, and the problem of foaming and exhausting is very easy to solve in the injection process, in addition, the insulating tube prepared by the vertical injection mode is easy to cause the difference between the tube end and the tube in the middle position, so that the tube density of the end is reduced, and the insulating performance is influenced.
Disclosure of Invention
The invention aims to solve the problem of providing an injection process of a prefabricated heat-insulating pipe, the heat-insulating pipe prepared by the injection process has complete and attractive pipeline, the density of a polyurethane heat-insulating layer in the pipe is uniform, and the heat-insulating effect of each position of the heat-insulating pipe is consistent; when the injection, use the slope foaming platform for the pipe fitting keeps 2-6 inclination to carry out the slope injection, is provided with sprue and gas vent on the high-end shutoff flange of slope simultaneously, can in time discharge intraductal bubble and gas along with the going on of injection.
In order to solve the technical problems, the invention adopts the technical scheme that: a prefabricated heat preservation pipe injection process sequentially comprises the steps of producing a polyethylene outer pipe, performing shot blasting and rust removal on the steel pipe, plugging a sleeve, injecting a polyurethane foam material, foaming, detecting quality and warehousing a finished product; the polyurethane foam material injection method comprises the following steps: fixing the pipe fitting with the plugged sleeve on an inclined foaming platform, adjusting the angle of the pipe fitting by the inclined foaming platform to enable the pipe fitting to form an inclination angle of 2-6 degrees with the horizontal direction, and then inserting an injection gun head of a foaming machine into an injection port for injecting materials; and after the material injection is finished, the pipe fitting is adjusted to the horizontal position by inclining the foaming platform.
In the technical scheme, the injection process is characterized in that the pipe fitting is kept in a 2-6-degree inclination angle state by inclining the foaming platform, and inclined injection is carried out; this injection technology can prevent to destroy the integrality of pipe fitting, and simultaneously, the polyurethane material flows to low by the eminence during the injection, can be so that the even of mixture, the later stage foaming of being convenient for makes evenly distributed in the pipeline simultaneously, guarantees that the distribution of each part is even unanimous. In the technical scheme, the pipe fitting is kept at the angle of 2-6 degrees to inject the polyurethane material, so that the polyurethane material can flow to any position of the pipe fitting uniformly, and meanwhile, if the angle is higher than 6 degrees to inject, only the bracket is arranged between the steel pipe and the polyethylene outer pipe to support, so that when the angle is higher than 6 degrees, the relative position of the steel pipe and the polyethylene outer pipe is easy to shift, the final product quality is influenced, in addition, when the angle is smaller than 2 degrees, the moving speed of the polyurethane material is low and close to the horizontal spreading speed, and the time required by injection is prolonged.
Further, in the step of injecting the polyurethane foaming material, the foaming machine is a polyurethane high-pressure foaming machine, the injection pressure is 20MPa, and the filling amount of the polyurethane is 80-90kg/m3。
Further, in the step of injecting the polyurethane foam material, the temperature difference between the temperature of the steel pipe and the temperature of the polyethylene outer pipe and the temperature of the polyurethane material is controlled to be less than or equal to 5 ℃, and the temperature of the steel pipe and the temperature of the polyethylene outer pipe are ensured to be higher than the temperature of the polyurethane material.
In the technical scheme, the temperature difference between the temperature of the steel pipe and the outer polyethylene pipe and the material temperature of the polyurethane is controlled to be less than or equal to 5 ℃, and the temperature of the steel pipe and the outer polyethylene pipe is ensured to be higher than the material temperature of the polyurethane; the normal flowing property of the polyurethane material in the injection process can be ensured, so that the polyurethane material is uniformly distributed in the tube, and the foaming and curing are carried out after the injection is finished; meanwhile, the temperature of the steel pipe and the polyethylene outer pipe is higher than that of the polyurethane, the good flowing property of the polyurethane can be kept, and the polyurethane can be filled in the pipe as soon as possible, and the material temperature of the polyurethane is preferably 25 ℃ and the temperature of the steel pipe and the polyethylene outer pipe is preferably 30 ℃.
Further, the sleeve plugging step specifically comprises: hoisting the treated steel pipe to a pipe penetrating platform, fixing the brackets on the steel pipe by iron wires according to the thickness of the heat-insulating layer, and uniformly installing the brackets at intervals according to the pipe diameter of each 6-10 groups of brackets; after the support is fixed, the outer polyethylene pipe is sleeved on the steel pipe with the support fixed, and then the two ends of the outer polyethylene pipe are sealed by plugging flanges.
Furthermore, in the sleeve plugging step, one plugging flange is provided with a filling port and an exhaust port, and the other plugging flange is not provided with a filling port and an exhaust port; 10-16 air outlets are arranged and uniformly distributed on the plugging flange; the blocking flange with the filling opening and the exhaust opening is located at one end of the pipe fitting at the higher position when the pipe fitting is inclined.
In the technical scheme, the plugging flange is provided with the injection port for injecting the polyurethane material into the pipe, and the plurality of exhaust ports are uniformly arranged, so that the gas in the pipe can be conveniently exhausted, and the polyurethane material can be uniformly distributed in the pipeline; the plugging flange with the injection port and the exhaust port is positioned at one end of a higher position when the pipe fitting is inclined, so that the injection gun head of the foaming machine can conveniently penetrate through the injection port to inject materials into the pipe fitting from the upper part, and the normal operation of injection is facilitated.
Further, the steps of producing the polyethylene outer pipe are as follows: and (3) extruding and molding the polyethylene by using a plastic extruder, wherein the extrusion molding comprises the steps of plasticizing, vacuum sizing molding, spray cooling, corona treatment, quality inspection and cutting, and the cut polyethylene outer pipe is placed into a semi-finished product warehouse for later use.
The density of the polyurethane heat-insulating layer at any position of the heat-insulating pipe prepared by the prefabricated heat-insulating pipe injection process is more than or equal to 70kg/m3And the difference between the densities of the polyurethane heat-insulating layers at any two positions is less than or equal to 5kg/m3。
The invention has the advantages and positive effects that:
1. compared with the horizontal injection method in the prior art, the injection process adopts an inclined injection method, so that the pipe fitting keeps an inclined angle of 2-6 degrees during injection, and the plugging flange positioned at one end of the inclined high position of the pipe fitting is provided with the injection port and the exhaust port, so that the material flows from the high position to the low position, the continuous injection of the material and the timely discharge of bubbles are facilitated, the uniform distribution of the material in the pipeline can be ensured, and the uniform and consistent distribution of all parts in the heat preservation pipe is ensured; thereby ensuring the heat preservation performance of each part to be consistent.
2. When the polyurethane foaming material is injected, the temperature difference value between the temperature of the steel pipe and the temperature of the polyethylene outer pipe and the temperature difference value of the polyurethane is less than or equal to 5 ℃, the temperature of the steel pipe and the temperature of the polyethylene outer pipe are higher than the temperature of the polyurethane, the normal flowing performance of the polyurethane material in the injection process can be ensured, the uniform distribution in the pipe is ensured, and the foaming and curing are carried out after the injection is finished.
3. The heat preservation pipe prepared by the injection process has consistent performance of each part and good heat preservation effect.
Drawings
FIG. 1 is a process flow diagram of a prefabricated insulated pipe injection process of the present invention;
FIG. 2 is a creep curve in a creep test of product 1;
in the figure: (262800h) creep deformation amount,. DELTA.S262800
1000h creep deformation, Delta S1000
③ 100h creep deformation, Delta S100
Creep (mm)
Time (h).
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings.
Example 1:
as shown in fig. 1, a prefabricated thermal insulation pipe injection process comprises the following steps:
a. producing the polyethylene outer pipe: extruding and molding polyethylene by using a plastic extruder with a large-diameter and thin-walled tube, wherein the extrusion molding is completed by plasticizing, vacuum sizing molding, spray cooling, corona treatment, quality inspection and cutting, and the cut polyethylene outer tube is put into a semi-finished product warehouse for later use;
b. performing shot blasting and rust removal on the steel pipe: performing shot blasting treatment on the steel pipe to remove oxide skin and dust on the surface of the steel pipe, so that the steel pipe and the heat-insulating layer of the heat-insulating pipe are tightly integrated into a whole;
c. plugging a sleeve: hoisting the treated steel pipe to a pipe penetrating platform, fixing the brackets on the steel pipe by iron wires according to the thickness of the heat-insulating layer, and uniformly installing the brackets at intervals according to the diameter of each pipe, wherein the brackets are 6-10 groups; after the support is fixed, sleeving the outer polyethylene pipe on the steel pipe with the support fixed, and then plugging and sealing two ends of the outer polyethylene pipe by using plugging flanges;
d. injecting a polyurethane foaming material: fixing the pipe fitting after the sleeve pipe is plugged on an inclined foaming platform, adjusting the angle of the pipe fitting through the inclined foaming platform to enable the pipe fitting to form an inclination angle of 2-6 degrees with the horizontal direction, and then inserting an injection gun head of a foaming machine into an injection port for injecting materials; after the material injection is finished, the pipe fitting is adjusted to a horizontal position by inclining the foaming platform;
e. foaming: horizontally standing and placing to foam and cure the polyurethane material inside; after foaming is finished for 5-25 minutes, removing the plugging flanges at two ends, and numbering the pipelines;
f. and (3) quality detection: and (4) detecting the pipeline, packaging qualified products and warehousing the qualified products, and storing the unqualified products in addition.
g. And (6) warehousing the finished product.
In step d of this embodiment, in injecting the polyurethane foam material, the pipe is kept at an angle of 2 to 6 ° to inject the polyurethane material, so that the polyurethane material can be conveniently and uniformly flowed to any position of the pipe, and meanwhile, if the angle is higher than 6 ° to inject, because only the bracket is used for supporting between the steel pipe and the polyethylene outer pipe, when the angle is higher than 6 °, the relative position between the steel pipe and the polyethylene outer pipe is easily shifted, which affects the final product quality, and when the angle is smaller than 2 °, the moving speed of the polyurethane material is slow, which is close to the horizontal spreading speed, and the time required for injection is increased. The inclination angle of the pipe fitting is adjusted according to different pipe diameters of products, when the diameter difference between the polyethylene outer pipe and the steel pipe is large, namely the thickness of the heat insulation layer is large, the inclination angle is kept small during injection, and the steel pipe and the polyethylene outer pipe can be ensured not to move relatively; the difference of footpath when polyethylene outer tube and steel pipe is less, and the thickness of heat preservation is less promptly, and increase injection inclination that this moment can be suitable for the polyurethane material flow speed increases, prevents to take place the phenomenon of jam when injecting the polyurethane material, guarantees to distribute evenly in the pipe fitting is inside.
In this embodiment, in the step c and the sleeve plugging step, two plugging flanges are included, wherein one plugging flange is provided with a filling port and an exhaust port, and the other plugging flange is not provided with a filling port and an exhaust port; 10-16 air outlets are arranged and uniformly distributed on the plugging flange; the blocking flange with the material filling opening and the air exhaust opening is positioned at one end of the higher position when the pipe fitting inclines. The plugging flange is provided with a material injection port for injecting polyurethane materials into the pipe, and a plurality of gas exhaust ports are uniformly arranged, so that gas in the pipe can be conveniently exhausted, and the polyurethane materials can be uniformly distributed in the pipeline; the plugging flange with the injection port and the exhaust port is positioned at one end of a higher position when the pipe fitting is inclined, so that the injection gun head of the foaming machine can conveniently penetrate through the injection port to inject materials into the pipe fitting from the upper part, and the normal operation of injection is facilitated.
In this embodiment, in the step of injecting the polyurethane foaming material, the foaming machine is a polyurethane high-pressure foaming machine, the injection pressure is 20MPa, and the filling amount of polyurethane is 80-90kg/m3. The embodiment adopts a PU600 polyurethane high-pressure foaming machine, ensures that the injection pressure is maintained at 20MPa, and ensures that isocyanate in a polyurethane material is fully mixed with combined polyether by keeping high-pressure injection during injection, thereby ensuring the foaming quality.
In this embodiment, in the step of injecting the polyurethane foam material, the temperature difference between the temperature of the steel pipe and the outer polyethylene pipe and the material temperature of the polyurethane is controlled to be less than or equal to 5 ℃, and the temperature of the steel pipe and the outer polyethylene pipe is ensured to be higher than the material temperature of the polyurethane; the normal flowing property of the polyurethane material in the injection process can be ensured, so that the polyurethane material is uniformly distributed in the tube, and the foaming and curing are carried out after the injection is finished; meanwhile, the temperature of the steel pipe and the polyethylene outer pipe is higher than that of the polyurethane, good fluidity of the polyurethane can be maintained, and the polyurethane can be filled in the pipe as soon as possible, and the material temperature of the polyurethane is preferably 25 ℃ and the temperature of the steel pipe and the polyethylene outer pipe is preferably 30 ℃.
In the embodiment, the density of the polyurethane heat-insulating layer at any position of the heat-insulating pipe produced by the injection process is more than or equal to 70kg/m3And the difference between the densities of the polyurethane heat-insulating layers at any two positions is less than or equal to 5kg/m3。
The products 1-5 in the following table are all products prepared by controlling different pipe diameters and filling amounts of polyurethane by using the process of example 1, and the pipe diameters and process parameters are shown in table 1:
TABLE 1 Process parameters for products 1-5
Respectively detecting the densities of the polyurethane heat-insulating layers at two ends, the middle, 1/4 and 3/4 of the prepared products 1-5 to judge whether the density of the polyurethane heat-insulating layer in the pipeline is uniform, wherein the average value of the five densities is used as the density of any position of the heat-insulating layer in the pipeline; the detection results are shown in table 2:
TABLE 2 Density of polyurethane insulation layers of products 1-5
| Item | First end | Second end | Intermediate (II) | 1/4 position | 3/4 position | Average density |
| Product 1 | 72.3kg/m3 | 74.8kg/m3 | 71.6kg/m3 | 70.5kg/m3 | 72.3kg/m3 | 72.3kg/m3 |
| Product 2 | 76.7kg/m3 | 77.0kg/m3 | 76.4kg/m3 | 75.9kg/m3 | 77.5kg/m3 | 76.7kg/m3 |
| Product 3 | 79.5kg/m3 | 79.3kg/m3 | 80.2kg/m3 | 79.6kg/m3 | 79.4kg/m3 | 79.6kg/m3 |
| Product 4 | 70.5kg/m3 | 72.3kg/m3 | 72.6kg/m3 | 71.5kg/m3 | 72.6kg/m3 | 71.9kg/m3 |
| Product 5 | 71.5kg/m3 | 72.4kg/m3 | 72.3kg/m3 | 72.9kg/m3 | 72.9kg/m3 | 72.4kg/m3 |
As can be seen from the experimental data in Table 2, the polyurethane insulation layer in the insulation pipe prepared by the injection process of the invention foams uniformly, and the density of the polyurethane insulation layer at any position is more than 70kg/m3(ii) a Subtracting the densities of different positions in the same product, wherein the difference is less than 5, namely the difference between the densities of the polyurethane heat-insulating layers at any two positions is less than 5kg/m3。
The prepared products 1 to 5 are detected, and various performances of the polyurethane heat-insulating layer in the pipe are detected, wherein the density is the density of any position in the polyurethane heat-insulating layer in the heat-insulating pipe (namely the average density in table 2), and the detection data are shown in table 3:
TABLE 3 Performance test data for polyurethane insulation layers in products 1-5
As can be seen from Table 3, the thermal insulation pipe produced by the injection process of the present invention has the advantages of uniform distribution of the polyurethane thermal insulation layer therein, good overall thermal insulation property, good thermal insulation performance and good quality, and all meet the quality requirements of the thermal insulation pipe. According to the data of the closed pore rate in the table, the thermal insulation pipe produced by the injection process has the advantages that the internal exhaust is good, the foaming is uniform, the internal polyurethane thermal insulation layer is uniformly distributed, the characteristics of all parts are kept consistent, and the thermal insulation pipe is convenient to use normally.
Taking the product 1 for creep test detection of the heat preservation pipe:
the test conditions are as follows:
1. the nominal diameter DN of the steel tube is 50mm, and the DC of the polyethylene outer tube is 125 mm.
2. Before the load is added in the formal test, the test piece is preheated at 140 +/-2 ℃ for one week.
3. Temperature rise speed of the test piece: when the temperature is lower than 100 ℃, the temperature is 25 ℃/h; when the temperature is higher than 100 ℃, the temperature is 50 ℃/h.
4. In the creep process: the outer polyethylene pipe is exposed to 23 +/-2 ℃ and the relative humidity of 50 +/-5% RH, and the working steel pipe is kept at the required medium temperature: test medium (steel pipe) temperature: 140 +/-2 ℃; experiment time: 1000 h; the temperature of the steel pipe is continuously recorded in the experimental process, and the temperature control deviation is +/-0.5 ℃; test load: 1.5 +/-0.01 kN and has no impact.
5. After the test, the temperature of the experiment is naturally reduced to 23 +/-2 ℃ at room temperature.
6. The number of the samples is 3, and the length of the sample is as follows: 200mm, wherein the length of the test segment is 100mm, and the average value of the test results of the three samples is taken as the test result.
The test data are shown in table 4, and the creep curve is shown in fig. 2:
TABLE 4 creep test results
From the experimental data of Table 4,. DELTA.S100And Δ S1000The connecting line between the two points extends to the position of 30 years according to the dotted line in the double logarithmic coordinates, the expected creep deformation amount of the pipeline can be calculated to be 18.3mm, and the creep curve is shown in figure 2. The product meets the standard requirements, and the creep test result of the heat-insulating pipe is qualified through detection.
The embodiments of the present invention have been described in detail, but the description is only for the preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.
Claims (7)
1. A prefabricated heat preservation pipe injection process sequentially comprises the steps of producing a polyethylene outer pipe, performing shot blasting and rust removal on the steel pipe, plugging a sleeve, injecting a polyurethane foam material, foaming, detecting quality and warehousing a finished product; the method is characterized in that: the steps of injecting the polyurethane foaming material are as follows: fixing the pipe fitting after the sleeve pipe is plugged on an inclined foaming platform, adjusting the angle of the pipe fitting through the inclined foaming platform to enable the pipe fitting to form an inclination angle of 2-6 degrees with the horizontal direction, and then inserting an injection gun head of a foaming machine into an injection port for injecting materials; and after the material injection is finished, the pipe fitting is adjusted to the horizontal position by inclining the foaming platform.
2. The injection process of a prefabricated thermal insulation pipe according to claim 1, characterized in that: in the step of injecting the polyurethane foaming material, the foaming machine is a polyurethane high-pressure foaming machine, the injection pressure is 20MPa, and the polyurethane is filledThe amount is 80-90kg/m3。
3. The injection process of a prefabricated thermal insulation pipe according to claim 2, characterized in that: in the step of injecting the polyurethane foaming material, the temperature difference between the temperature of the steel pipe and the temperature of the polyethylene outer pipe and the temperature of the polyurethane is controlled to be less than or equal to 5 ℃, and the temperature of the steel pipe and the temperature of the polyethylene outer pipe are ensured to be higher than the temperature of the polyurethane.
4. The injection process of a prefabricated thermal insulation pipe according to claim 1, characterized in that: the sleeve plugging step specifically comprises the following steps: hoisting the treated steel pipe to a pipe penetrating platform, fixing the brackets on the steel pipe by iron wires according to the thickness of the heat-insulating layer, and uniformly installing the brackets at intervals according to the diameter of each pipe, wherein the brackets are 6-10 groups; after the support is fixed, the outer polyethylene pipe is sleeved on the steel pipe with the support fixed, and then the two ends of the outer polyethylene pipe are sealed by plugging flanges.
5. The injection process of a prefabricated thermal insulation pipe according to claim 4, characterized in that: in the step of plugging the sleeve, one plugging flange is provided with a filling port and an exhaust port; 10-16 air outlets are arranged and uniformly distributed on the plugging flange; the blocking flange with the filling opening and the exhaust opening is located at one end of the pipe fitting at the higher position when the pipe fitting is inclined.
6. The injection process of a prefabricated thermal insulation pipe according to claim 1, characterized in that: the production method of the polyethylene outer pipe comprises the following steps: and (3) extruding and molding the polyethylene by using a plastic extruder, wherein the extrusion molding is completed by plasticizing, vacuum sizing molding, spraying and cooling, corona treatment, quality inspection and cutting, and the cut polyethylene outer pipe is put into a semi-finished product warehouse for later use.
7. The insulated pipe manufactured by the injection process of the prefabricated insulated pipe according to any one of claims 1 to 6, wherein: the polyurethane heat-insulating layer at any position in the heat-insulating pipeThe density is more than or equal to 70kg/m3And the difference between the densities of the polyurethane heat-insulating layers at any two positions is less than or equal to 5kg/m3。
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113733448A (en) * | 2021-09-02 | 2021-12-03 | 芜湖达锦新材料科技有限公司 | Method for manufacturing heat-insulating pipe with flame-retardant effect for air conditioner made of modified high-molecular polyethylene material |
| CN114227967A (en) * | 2021-11-19 | 2022-03-25 | 中投(天津)智能管道股份有限公司 | Application method of cyclopentane foaming system polyurethane material in heat insulation pipeline |
| CN115122182A (en) * | 2022-07-26 | 2022-09-30 | 北京市热力集团有限责任公司 | Intraductal spiral weld equipment of polishing and insulating tube production system |
| CN117386896A (en) * | 2023-12-12 | 2024-01-12 | 江苏中圣管道工程技术有限公司 | Environment-friendly prefabricated heat-insulating pipeline based on foaming hardening in sleeve and preparation method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3935632A (en) * | 1973-07-02 | 1976-02-03 | Continental Oil Company | Method of preparing an insulated negative buoyancy flow line |
| CN103692603A (en) * | 2013-11-29 | 2014-04-02 | 中投（天津）热能装备发展有限公司 | Polyurethane inclined foaming platform of prefabricated directly-buried thermal insulation pipe |
| CN103822018A (en) * | 2013-11-29 | 2014-05-28 | 中投（天津）热能装备发展有限公司 | Multi-station prefabricated directly-buried thermal insulation pipe polyurethane foaming platform |
| CN104985741A (en) * | 2015-06-25 | 2015-10-21 | 中投（天津）热能装备发展有限公司 | Multi-aperture foaming platform for prefabricated direct-buried polyurethane heat insulation pipes |
| CN107448691A (en) * | 2017-07-18 | 2017-12-08 | 河南三杰热电科技股份有限公司 | One kind is aerial to use polyurethane foam prefabricated thermal insulation pipeline and production method |
| CN111645252A (en) * | 2020-07-07 | 2020-09-11 | 唐山兴邦管道工程设备有限公司 | Novel foaming platform for heat insulation pipeline |
-
2020
- 2020-10-22 CN CN202011139450.0A patent/CN112428504A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3935632A (en) * | 1973-07-02 | 1976-02-03 | Continental Oil Company | Method of preparing an insulated negative buoyancy flow line |
| CN103692603A (en) * | 2013-11-29 | 2014-04-02 | 中投（天津）热能装备发展有限公司 | Polyurethane inclined foaming platform of prefabricated directly-buried thermal insulation pipe |
| CN103822018A (en) * | 2013-11-29 | 2014-05-28 | 中投（天津）热能装备发展有限公司 | Multi-station prefabricated directly-buried thermal insulation pipe polyurethane foaming platform |
| CN104985741A (en) * | 2015-06-25 | 2015-10-21 | 中投（天津）热能装备发展有限公司 | Multi-aperture foaming platform for prefabricated direct-buried polyurethane heat insulation pipes |
| CN107448691A (en) * | 2017-07-18 | 2017-12-08 | 河南三杰热电科技股份有限公司 | One kind is aerial to use polyurethane foam prefabricated thermal insulation pipeline and production method |
| CN111645252A (en) * | 2020-07-07 | 2020-09-11 | 唐山兴邦管道工程设备有限公司 | Novel foaming platform for heat insulation pipeline |
Non-Patent Citations (2)
| Title |
|---|
| 中国绝热隔音材料协会: "《绝热材料与绝热工程实用手册》", 31 July 1998, 中国建材工业出版社 * |
| 张玉龙等: "《塑料低压成型制品配方设计与加工实例》", 31 January 2006, 国防工业出版社 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113733448A (en) * | 2021-09-02 | 2021-12-03 | 芜湖达锦新材料科技有限公司 | Method for manufacturing heat-insulating pipe with flame-retardant effect for air conditioner made of modified high-molecular polyethylene material |
| CN114227967A (en) * | 2021-11-19 | 2022-03-25 | 中投(天津)智能管道股份有限公司 | Application method of cyclopentane foaming system polyurethane material in heat insulation pipeline |
| CN115122182A (en) * | 2022-07-26 | 2022-09-30 | 北京市热力集团有限责任公司 | Intraductal spiral weld equipment of polishing and insulating tube production system |
| CN117386896A (en) * | 2023-12-12 | 2024-01-12 | 江苏中圣管道工程技术有限公司 | Environment-friendly prefabricated heat-insulating pipeline based on foaming hardening in sleeve and preparation method thereof |
| CN117386896B (en) * | 2023-12-12 | 2024-03-01 | 江苏中圣管道工程技术有限公司 | Environment-friendly prefabricated heat-insulating pipeline based on foaming hardening in sleeve and preparation method thereof |
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