A girth weld local solution heat treatment apparatus and method for a stainless steel vessel

Abstract

The application provides a local solid solution heat treatment device and method for girth weld of a stainless steel container, the side wall of the stainless steel container is provided with a girth weld, and the treatment device comprises: a ring-shaped sprayer arranged in the stainless steel container and adapted to the position of the girth weld and used for spraying a coolant to the girth weld; a pair of induction heaters arranged symmetrically outside the stainless steel container and close to the girth weld and used for heating the girth weld; and a plurality of thermocouples uniformly distributed around the girth weld and used for measuring the temperature distribution of the girth weld. The combination of the ring-shaped sprayer, the pair of induction heaters and the plurality of thermocouples realizes automatic control of the heating speed and the cooling speed of the solid solution heat treatment, ensures the comprehensive performance of the product weld and the base metal on both sides, avoids the problem of a large amount of drainage generated by the traditional cooling method, and saves resource consumption.

Description

Technical Field

[0001] This invention belongs to the field of welding heat treatment technology for large thin-walled stainless steel containers, specifically relating to a device and method for local solution heat treatment of circumferential welds of stainless steel containers. Background Technology

[0002] To eliminate stress and refine the microstructure, large thin-walled stainless steel containers must undergo overall solution treatment after processing and passing non-destructive testing.

[0003] The overall size of the large thin-walled stainless steel container is too long (equipment length > 10 meters), and the depth of the cooling water tank for solution treatment in the manufacturer is limited. Therefore, the equipment needs to be heat-treated in sections. The specific steps are: (1) perform overall solution treatment in sections; (2) weld the closure seam; (3) perform local solution treatment on the closure seam.

[0004] Currently, local solution treatment is generally carried out by heating in a local heat treatment furnace (cassette furnace), and the solution holding temperature is usually controlled at 1050-1100℃.

[0005] However, the unpacking time of the local heat treatment furnace is relatively long, which cannot meet the requirement that the equipment products should be cooled rapidly immediately after solution treatment. At the same time, thin-walled stainless steel containers are prone to deformation when lifted into the water. New methods must be adopted to ensure the solution treatment quality. Based on this background, this invention studies a device and method for local solution heat treatment of the circumferential weld seam of large thin-walled stainless steel containers after welding. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a device and method for local solution heat treatment of circumferential welds in stainless steel containers. This device and method can automatically control the heating and cooling rates of the solution heat treatment, combining induction heating and cooling to improve operability.

[0007] To achieve the above objectives, a first aspect of the present invention provides a local solution heat treatment apparatus for the circumferential weld of a stainless steel container, wherein the circumferential weld is provided on the side wall of the stainless steel container, comprising:

[0008] An annular sprayer, located inside the stainless steel container and adapted to the position of the annular weld, is used to spray coolant onto the annular weld.

[0009] A pair of induction heaters are symmetrically arranged near the circumferential weld on the outside of the stainless steel container for heating the circumferential weld.

[0010] Multiple thermocouples are evenly distributed around the circumferential weld to measure the temperature distribution of the circumferential weld.

[0011] A second aspect of the present invention provides a method for local solution heat treatment of the circumferential weld of a stainless steel container, the method employing the aforementioned heat treatment apparatus and comprising the following steps:

[0012] Fixing the ring sprayer: Place the ring sprayer inside the stainless steel container and fix it in place after adapting it to the position of the ring weld.

[0013] Set up a pair of induction heaters: Place a pair of induction heaters near the circumferential weld and symmetrically on the outside of the stainless steel container;

[0014] Setting up thermocouples: Distribute multiple thermocouples evenly around the circumferential weld.

[0015] Heating the circumferential weld: Turn on the power and turn on a pair of induction heaters to heat the circumferential weld on the outside of the stainless steel container;

[0016] Temperature measurement: The temperature distribution of the circumferential weld and its surrounding area is measured using multiple thermocouples;

[0017] Spraying the circumferential weld: Turn on the annular sprayer to spray coolant onto the circumferential weld.

[0018] The effects of this invention are:

[0019] (1) This invention achieves automatic control of the heating and cooling rates of solution heat treatment by combining an annular sprayer, a pair of induction heaters and multiple thermocouples, ensuring the comprehensive performance of the product weld and the base material on both sides, improving operability, avoiding the large amount of drainage problems caused by traditional cooling methods, and saving resource consumption.

[0020] (2) The spray holes of the pair of spray rings of the annular sprayer of the present invention are arranged opposite each other, which makes the spray efficiency of coolant higher and the cooling speed of the annular weld faster; at the same time, the hollow annular structure of the spray ring is adapted to the annular inner wall of the stainless steel container, making the temperature change of the annular weld more uniform.

[0021] (3) The pair of triangular supports of the present invention can not only stably support the annular sprayer, but also make it easy to fix inside the stainless steel container.

[0022] (4) The axial tube of the present invention not only supports the radial tube, distribution ring, hollow connecting tube and spray ring, but also evenly distributes the coolant to the radial tube, distribution ring, hollow connecting tube and spray ring in sequence.

[0023] (5) Based on the size, material and heating technology requirements of the stainless steel container, the present invention selects an induction heater through thermal calculation to ensure that the rated power of the induction heater matches the actual heating requirements of the stainless steel container.

[0024] (6) The roller frame of the present invention is located at the lower part of the stainless steel container, which can control the stainless steel container to rotate along its own axis so that it is heated evenly.

[0025] (7) The controller of the present invention can control the power of a pair of induction heaters to heat the circumferential weld and keep it at a constant temperature according to the temperature distribution measured by multiple thermocouples, so that the control of the solution heat treatment of the circumferential weld of stainless steel container is more precise.

[0026] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0027] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0028] Figure 1A This is a schematic diagram of the overall structure of a local solution heat treatment device for the circumferential weld of a stainless steel container provided by the present invention.

[0029] Figure 1B This is a cross-sectional view of a device for local solution heat treatment of the circumferential weld of a stainless steel container provided by the present invention.

[0030] Figure 2 This is a schematic diagram of the structure of the annular sprayer of a local solution heat treatment device for the circumferential weld of a stainless steel container provided by the present invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1-Stainless steel container; 2-Circumferential weld; 3-Roller frame; 4-Annular sprayer; 5-Induction heater; 6-Thermocouple; 7-Insulation cotton; 8-Coolant storage container; 9-Connecting hose.

[0033] 101-Spray ring; 102-Distribution ring; 103-Hollow connecting pipe; 104-Radial pipe; 105-Axial pipe; 106-Support; 107-Spray hole; 108-Coolant injection port. Detailed Implementation

[0034] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0035] In this disclosure, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its normal operating state, for example, referring to the drawing orientation of Figure 1; "inner" and "outer" refer to their position relative to the outline of the device. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0036] This invention provides a local solution heat treatment apparatus for the circumferential weld 2 of a stainless steel container 1. The stainless steel container 1 has a circumferential weld 2 on its side wall, such as... Figure 1A and Figure 1B As shown, it includes:

[0037] An annular sprayer 4 is located inside the stainless steel container 1 and is adapted to the position of the annular weld 2, and is used to spray coolant onto the annular weld 2.

[0038] A pair of induction heaters 5 are located near the circumferential weld 2 and symmetrically arranged on the outside of the stainless steel container 1 for heating the circumferential weld 2;

[0039] Multiple thermocouples 6 are evenly distributed around the circumferential weld 2 to measure the temperature distribution of the circumferential weld 2.

[0040] According to the present invention, the annular sprayer 4 includes:

[0041] A pair of spray rings 101, each spray ring 101 is a hollow ring, and each spray ring 101 has a plurality of spray holes 107 evenly distributed on one side of its ring surface. Each spray hole 107 is axially aligned with the ring weld 2 and is used to spray coolant onto the ring weld 2.

[0042] A pair of distribution rings 102, each distribution ring 102 being a hollow circular ring, with the outer ring surface of each distribution ring 102 connected to the inner ring surface of a sprayer via multiple hollow connecting pipes 103 of equal length.

[0043] A pair of radial tubes 104, with the inner annular surface of each distributor connected by a radial tube 104.

[0044] Axial tube 105, which is perpendicularly connected to a pair of radial tubes 104.

[0045] The spray holes 107 of the pair of spray rings 101 of the annular sprayer 4 of the present invention, which are arranged opposite each other, make the spray efficiency of coolant higher and the cooling speed of the annular weld 2 faster; at the same time, the hollow annular structure of the spray ring 101 is adapted to the annular inner wall of the stainless steel container 1, making the temperature change of the annular weld 2 more uniform.

[0046] According to the present invention, the annular sprayer 4 also includes a pair of supports 106.

[0047] The support 106 is triangular in shape.

[0048] A pair of brackets 106 are respectively set at both ends of the axial tube 105 to support and fix the annular sprayer 4.

[0049] One end of the axial tube 105 is closed, and the other end is provided with a coolant injection port 108.

[0050] The coolant inlet 108 is connected to the outlet of the coolant reservoir 8 via a connecting hose 9.

[0051] The coolant reservoir 8 is equipped with a coolant output switch.

[0052] The pair of triangular supports 106 of the present invention can not only stably support the annular sprayer 4, but also easily fix it inside the stainless steel container 1.

[0053] Preferably, a pair of spray rings 101 are symmetrically arranged on both sides of the circumferential weld 2, and the spray holes 107 of the pair of spray rings 101 are arranged opposite each other to spray coolant onto the circumferential weld 2 simultaneously.

[0054] According to the present invention, each spray ring 101 and a distribution ring 102 connected thereto are in the same plane.

[0055] The axis of the axial tube 105 is perpendicular to the plane of the bracket 106.

[0056] According to a preferred embodiment of the present invention, the rated power of the induction heater 5 is calculated according to the following formula:

[0057]

[0058] Where P is the rated power of the induction heater, C is the average specific heat capacity of stainless steel, T1 is the initial temperature of the stainless steel container, T2 is the heating temperature of the stainless steel container, η is the total efficiency of the heating system, ρ is the density of stainless steel, δ is the penetration depth, R is the outer diameter of the stainless steel container, L1 is the length of the heating base material, and t is the penetration time.

[0059] Based on the size, material, and heating technology requirements of the stainless steel container 1, this invention selects an induction heater 5 through thermal calculations. The modular induction heater 5 makes its selection more flexible.

[0060] According to the present invention, the processing device further includes thermal insulation cotton 7.

[0061] Insulation cotton 7 is used to seal the open end of the stainless steel container 1 to ensure the solution heat treatment effect of the circumferential weld 2 of the stainless steel container 1.

[0062] According to the present invention, the processing apparatus further includes a controller (not shown).

[0063] A controller (not shown) is used to control a pair of induction heaters 5 to heat the circumferential weld 2 according to the temperature distribution.

[0064] In this invention, the heating of the circumferential weld 2 by a pair of induction heaters 5 is divided into two stages: heating and constant temperature holding. In the heating stage, the controller (not shown) controls the power of the pair of induction heaters 5 to slowly heat the circumferential weld 2 based on the real-time temperature feedback from the thermocouple 6, ensuring that the temperature difference between the inner and outer walls of the circumferential weld 2 is controllable. In the constant temperature holding stage, the controller (not shown) controls the power of the pair of induction heaters 5 to hold the circumferential weld 2 based on the real-time temperature feedback from the thermocouple 6.

[0065] According to the present invention, the processing device further includes a roller frame 3.

[0066] The roller frame 3 is located at the lower part of the stainless steel container 1 and is used to control the stainless steel container 1 to rotate slowly along its own axis to ensure that the circumferential weld 2, which requires solution heat treatment, is heated evenly.

[0067] The present invention also provides a method for local solution treatment of the circumferential weld 2 of a stainless steel container 1, the method comprising the following steps:

[0068] Fixing the annular sprayer 4: Place the annular sprayer 4 inside the stainless steel container 1 and fix it after it is aligned with the position of the annular weld 2;

[0069] Set up a pair of induction heaters 5: Place a pair of induction heaters 5 close to the circumferential weld 2 and symmetrically outside the stainless steel container 1;

[0070] Set thermocouples 6: Distribute multiple thermocouples 6 evenly around the circumferential weld 2;

[0071] Heating the circumferential weld 2: Turn on the power and turn on a pair of induction heaters 5 to heat the circumferential weld 2 on the outside of the stainless steel container 1;

[0072] Temperature measurement: The temperature distribution of the circumferential weld 2 and its surrounding area was measured using multiple thermocouples 6;

[0073] Spraying circumferential weld 2: Turn on the annular sprayer 4 to spray coolant into circumferential weld 2.

[0074] To more precisely control the solution heat treatment process of the circumferential weld of stainless steel containers, the above-mentioned local solution treatment method also includes the following steps:

[0075] Open end sealing: Before heating the circumferential weld 2, use insulation cotton 7 to seal the open end of the stainless steel container 1;

[0076] Set roller frame 3: Before heating the circumferential weld 2, set roller frame 3 at the bottom of stainless steel container 1;

[0077] Rotary heating: During the heating process of the circumferential weld 2, the stainless steel container 1 is controlled to rotate axially using a roller frame 3;

[0078] Heating of circumferential weld 2: The controller (not shown) controls the power of a pair of induction heaters 5 to heat the circumferential weld 2 according to the temperature distribution;

[0079] Constant temperature heating of circumferential weld 2: The controller (not shown) controls the power of a pair of induction heaters 5 to maintain the constant temperature of circumferential weld 2 according to the temperature distribution;

[0080] Remove the pair of induction heaters 5: After the constant temperature heating of the circumferential weld 2 is completed, turn off the pair of induction heaters 5 and remove the equipment;

[0081] Spraying of circumferential weld 2: After removing a pair of induction heaters 5, turn on the coolant output switch of coolant reservoir 8 to spray circumferential weld 2.

[0082] The present invention will be described in more detail below through embodiments.

[0083] Example

[0084] like Figure 1A and Figure 1B As shown, this embodiment provides a local solution heat treatment apparatus for the circumferential weld 2 of a stainless steel container 1. The side wall of the stainless steel container 1 is provided with a circumferential weld 2, including:

[0085] An annular sprayer 4 is located inside the stainless steel container 1 and is adapted to the position of the annular weld 2, and is used to spray coolant onto the annular weld 2.

[0086] A pair of induction heaters 5 are located near the circumferential weld 2 and symmetrically arranged on the outside of the stainless steel container 1 for heating the circumferential weld 2;

[0087] Multiple thermocouples 6 are evenly distributed around the circumferential weld 2 to measure the temperature distribution of the circumferential weld 2.

[0088] like Figure 2 As shown, the annular sprayer 4 in this embodiment includes:

[0089] A pair of spray rings 101, each spray ring 101 is a hollow ring, and each spray ring 101 has a plurality of spray holes 107 evenly distributed on one side of its ring surface. Each spray hole 107 is axially aligned with the ring weld 2 and is used to spray coolant onto the ring weld 2.

[0090] A pair of distribution rings 102, each distribution ring 102 being a hollow circular ring, with the outer ring surface of each distribution ring 102 connected to the inner ring surface of a sprayer via multiple hollow connecting pipes 103 of equal length.

[0091] A pair of radial tubes 104, with the inner annular surface of each distributor connected by a radial tube 104.

[0092] Axial tube 105, which is perpendicularly connected to a pair of radial tubes 104.

[0093] This embodiment provides a method for local solution treatment of the circumferential weld 2 of a stainless steel container 1, including the following steps:

[0094] Fixing the annular sprayer 4: Place the annular sprayer 4 inside the stainless steel container 1 and fix it after it is aligned with the position of the annular weld 2;

[0095] Set up a pair of induction heaters 5: Place a pair of induction heaters 5 close to the circumferential weld 2 and symmetrically outside the stainless steel container 1;

[0096] Set thermocouples 6: Distribute multiple thermocouples 6 evenly around the circumferential weld 2;

[0097] Heating the circumferential weld 2: Turn on the power and turn on a pair of induction heaters 5 to heat the circumferential weld 2 on the outside of the stainless steel container 1;

[0098] Open end sealing: Before heating the circumferential weld 2, use insulation cotton 7 to seal the open end of the stainless steel container 1;

[0099] Set roller frame 3: Before heating the circumferential weld 2, set roller frame 3 at the bottom of stainless steel container 1;

[0100] Rotary heating: During the heating process of the circumferential weld 2, the stainless steel container 1 is controlled to rotate axially using a roller frame 3;

[0101] Temperature measurement: The temperature distribution of the circumferential weld 2 and its surrounding area was measured using multiple thermocouples 6;

[0102] Heating of circumferential weld 2: The controller (not shown) controls the power of a pair of induction heaters 5 to heat the circumferential weld 2 according to the temperature distribution;

[0103] Constant temperature heating of circumferential weld 2: The controller (not shown) controls the power of a pair of induction heaters 5 to maintain the constant temperature of circumferential weld 2 according to the temperature distribution;

[0104] Remove the pair of induction heaters 5: After the constant temperature heating of the circumferential weld 2 is completed, turn off the pair of induction heaters 5 and remove the equipment;

[0105] Spraying of circumferential weld 2: After removing a pair of induction heaters 5, turn on the coolant output switch of coolant reservoir 8 to spray circumferential weld 2.

[0106] This embodiment achieves automatic control of the heating and cooling rates of solution heat treatment by combining an annular sprayer 4, a pair of induction heaters 5, and multiple thermocouples 6. This ensures the comprehensive performance of the product weld and the base material on both sides, improves operability, avoids the large amount of drainage problems caused by traditional cooling methods, and saves resource consumption.

[0107] In this embodiment, the spray holes 107 of the pair of spray rings 101 of the annular sprayer 4 are arranged opposite each other, which makes the spray efficiency of coolant higher and the cooling speed of the annular weld faster. At the same time, the hollow annular structure of the spray ring 101 is adapted to the annular inner wall of the stainless steel container, which makes the temperature change of the annular weld more uniform.

[0108] The controller (not shown) in this embodiment can switch the induction heater 5, set the heat preservation time of the stainless steel container 1, or set the spraying time of the annular sprayer 4 according to the temperature distribution measured by multiple thermocouples 6, so that the control of the solution heat treatment of the annular weld 2 of the stainless steel container 1 is more precise.

[0109] The embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A device for local solution heat treatment of a girth weld of a stainless steel vessel, a side wall of the stainless steel vessel being provided with the girth weld, characterized in that, The processing device comprises: a ring-shaped sprayer arranged inside the stainless steel container and adapted to the position of the girth weld for spraying coolant to the girth weld; a pair of induction heaters arranged symmetrically outside the stainless steel container near the girth weld for heating the girth weld; a plurality of thermocouples arranged around the girth weld for measuring the temperature distribution of the girth weld; the rated power of the induction heaters is calculated according to the following formula: where P is the rated power of the induction heater, C is the average specific heat capacity of the stainless steel, T1 is the initial temperature of the stainless steel container, T2 is the heating temperature of the stainless steel container, is the total efficiency of the heating system, p is the density of the stainless steel, d is the penetration depth, R is the outer diameter of the stainless steel container, L1 is the length of the heated base material, and t is the heat penetration time.

2. The heat treatment apparatus according to claim 1, wherein The ring-shaped sprayer comprises: a pair of spraying rings in the shape of hollow annular rings, the side surface of each spraying ring is uniformly provided with a plurality of spraying holes, the axial direction of each spraying hole is opposite to the girth weld for spraying coolant to the girth weld; a pair of distribution rings in the shape of hollow annular rings, the outer side surface of each distribution ring is communicated with the inner side surface of one of the spraying rings through a plurality of hollow connecting pipes with equal length; a pair of radial pipes, the inner side surface of each distribution ring is communicated through one of the radial pipes; an axial pipe vertically communicating the pair of radial pipes.

3. The heat treatment apparatus according to claim 2, wherein The ring-shaped sprayer further comprises a pair of supports; the supports are in the shape of triangle; the pair of supports are arranged at the two ends of the axial pipe respectively for supporting and fixing the ring-shaped sprayer; one end of the axial pipe is closed and the other end is provided with a coolant injection port; the coolant injection port is connected with the output port of a coolant storage through a connecting hose; the coolant storage is provided with a coolant output switch.

4. The heat treatment apparatus according to claim 3, wherein The pair of spraying rings are symmetrically arranged at the two sides of the girth weld, the spraying holes of the pair of spraying rings are arranged in pairs opposite to each other for simultaneously spraying coolant to the opposite girth weld.

5. The heat treatment apparatus according to claim 4, wherein Each spraying ring and the distribution ring connected therewith are in the same plane; the axis of the axial pipe is perpendicular to the plane of the supports.

6. The heat treatment apparatus according to claim 1, wherein The processing device further comprises heat preservation cotton; the heat preservation cotton is used for plugging the open end of the stainless steel container.

7. The heat treatment apparatus according to claim 1, wherein The processing device further comprises a controller; the controller is used for controlling the pair of induction heaters to heat the girth weld according to the temperature distribution.

8. The heat treatment apparatus according to claim 1, wherein The processing device further comprises a roller frame; the roller frame is arranged at the lower part of the stainless steel container for controlling the rotation of the stainless steel container along its axis.

9. A method of local solution heat treatment of girth welds of stainless steel vessels using the heat treatment device according to any one of claims 1 to 8, characterized in that The processing method comprises the following steps: fixing the ring-shaped sprayer: fixing the ring-shaped sprayer inside the stainless steel container and adapted to the position of the girth weld; arranging the pair of induction heaters: arranging the pair of induction heaters near the girth weld and symmetrically outside the stainless steel container; arranging the thermocouples: arranging the plurality of thermocouples around the girth weld; heating the girth weld: connecting the power supply and turning on the pair of induction heaters to heat the girth weld outside the stainless steel container; temperature measurement: measuring the temperature distribution of the girth weld and its periphery by the plurality of thermocouples; spraying the girth weld: turning on the ring-shaped sprayer to spray coolant to the girth weld.

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