An electrically heated device with adjustable diameter

Abstract

The application discloses a diameter-adjustable electric heating device, which comprises a plurality of fixed units arranged in a circular arc shape, and the inner surface of the circular arc is matched with the radial outer surface of a cylindrical workpiece to be heated; each fixed unit is in the shape of a cubic frame and is hingedly connected with adjacent fixed units; one side of each fixed unit is provided with a concave arc surface which is adapted to the inner surface of the circular arc; a plurality of electric heaters are arranged on the concave arc surface of each fixed unit; and a telescopic moving rack is used for fixing, supporting and moving the plurality of fixed units arranged in a circular arc shape. The modular fixed units in the form of assembly are used, the number of the hingedly connected heating fixed units can be increased or reduced at will according to the diameter of the workpiece to be heated, and one side of each fixed unit is provided with a concave arc surface to make it present a corresponding arc, so that the requirement of heating the girth joint of the cylinder with different diameters is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric heater device, in particular to a diameter-adjustable electric heating device. BACKGROUND

[0002] In the manufacturing process of pressure vessels, preheating before welding and hydrogen removal treatment after welding are required due to the material and wall thickness. When the equipment is too long, it needs to be segmented for furnace heat treatment, and local heat treatment is carried out after the segmented girth weld is assembled. When the cylinder diameter is large and horizontal assembly is adopted, the preheating and local heat treatment of the girth weld become more difficult. At present, preheating and post-heating can be achieved by flame heating and electric heating, while local heat treatment can only be achieved by electric heating. Among them, flame heating is to arrange nozzles around the weld, and to heat by burning acetylene or propane gas. When using flame preheating, it is difficult to keep the temperature of the joint uniform and difficult to control accurately, and the preheating effect is poor and not very environmentally friendly. Electric heating preheating is to connect electric heating sheets in series with iron wires, wrap the weld on the upper part of the girth weld, or arrange a section of heating sheet below the girth weld for preheating. The disadvantage is that it can only heat the local area of the weld, the temperature is not uniform, the operation is complex, the preparation time and preheating time are long, and due to the axial movement of the supporting roller, the weld deviates from the heating sheet, which needs to be adjusted frequently. The workload is large. Especially when the diameter is large, a scaffold needs to be erected for cooperation, and it cannot be reused. Each weld needs to be re-suspended with heating sheets and scaffolds, which greatly increases the manufacturing cost and safety risk. When using electric heating sheets for post-heating or local heat treatment of the weld, the electric heating sheets are first connected in series with iron wires, and then covered on the entire circle of the weld, and the outside is wrapped with thermal insulation cotton. The main fastening measure is to use iron wire to bandage, which has a large workload. During the heat treatment process, the iron wire becomes loose due to heating, so that the heating sheet and the thermocouple cannot be tightly attached to the weld, which seriously affects the effect of local heat treatment.

[0003] Based on this background, the present application researches a diameter-adjustable electric heating device. SUMMARY

[0004] The technical problem to be solved by the present application is that, in view of the deficiencies of the prior art, a diameter-adjustable electric heating device is proposed to solve the problem that the heating sheet and the thermocouple cannot be tightly attached to the weld due to thermal expansion during the heat treatment process.

[0005] In order to achieve the above-mentioned purpose, the present application provides a diameter-adjustable electric heating device, comprising:

[0006] A plurality of fixed units are arranged in a circular arc shape, and the inner surface of the circular arc is matched with the radial outer surface of the cylindrical workpiece to be heated. Each fixed unit is in the shape of a cubic frame and is hingedly connected with adjacent fixed units. One side of each fixed unit is provided with a concave arc surface which is adapted to the inner surface of the circular arc.

[0007] A plurality of electric heaters are arranged on the concave arc surface of each fixed unit.

[0008] A telescopic moving rack is used to fix, support and move the plurality of fixed units arranged in a circular arc shape.

[0009] The present application has the following effects:

[0010] (1) The diameter-adjustable electric heating device can increase or decrease the number of heating fixed units according to the diameter of the workpiece to be heated. The fixed units are hingedly connected with each other, and one side of each fixed unit is provided with a concave arc surface to present a corresponding arc. The fixed unit is modularized, simple to operate, and easy to disassemble and assemble, which is beneficial to improve work efficiency.

[0011] (2) The diameter-adjustable electric heating device uses a telescopic moving rack which can be reused, greatly facilitating the work of preheating the cylinder segment.

[0012] (3) The telescopic moving rack of the diameter-adjustable electric heating device has a reasonable structure design. Under the premise of ensuring safe use and not falling, the ratio of the ground area and the height of the rack is controlled within the most reasonable range, and the moving and adjusting are convenient.

[0013] (4) The fixed units of the diameter-adjustable electric heating device are hingedly connected through different hole positions, accurately presenting the required arc, so that the electric heater is closely attached to the workpiece to be heated, improving the heating efficiency.

[0014] (5) In addition to meeting the basic requirements of disassembling and assembling the fixed units, after the bolt is fastened, each fixed unit is connected to form a rigid whole, and the overall structural rigidity is greatly enhanced. At the same time, the structure design of the fixed unit also considers the function of the temporary ladder. When the fixed unit needs to be increased or decreased or the electric heater needs to be temporarily repaired, the worker can use the ladder to go up and down without the need for additional climbing equipment. This is the most significant difference between the present device and other similar tools.

[0015] (6) The diameter-adjustable electric heating device provided by the application can be used for unilateral or bilateral setting of the cylinder segment according to the need of the workpiece heating temperature, which is beneficial to the arrangement of the tool environment, and the site becomes standard and neat, and the safety degree is greatly improved compared with the previous temporary support.

[0016] (7) The diameter-adjustable electric heating device provided by the application, the height-adjustable trapezoidal rack is used for the working condition that the relative distance of the two rolling tire changing devices of the cylindrical workpiece is close, and the trapezoidal short side of the height-adjustable trapezoidal rack can enter the lower side of the cylinder segment.

[0017] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the several views, in which:

[0019] Figure 1 is the overall structure schematic diagram of the diameter-adjustable electric heating device provided by the application.

[0020] Figure 2 is the right view of the overall structure schematic diagram of the diameter-adjustable electric heating device in Figure 1

[0021] Figure 3 is the top view of the overall structure schematic diagram of the diameter-adjustable electric heating device in Figure 1

[0022] Figure 4 is the three-dimensional model schematic diagram of the diameter-adjustable electric heating device provided by the application.

[0023] Figure 5 is the fixed unit structure schematic diagram of the diameter-adjustable electric heating device provided by the application.

[0024] Explanation of reference signs:

[0025] 1 - telescopic moving rack, 2 - fixed unit, 3 - cylindrical workpiece, 4 - electric heater;

[0026] 101 - fixing mechanism, 102 - support adjusting rod, 103 - telescopic sleeve, 104 - universal wheel;

[0027] 201 - arc-shaped column, 202 - support cross bar, 203 - elastic steel plate, 204 - vertical column, 205 - reinforcing cross beam, 206 - long strip-shaped hinged plate, 207 - fan-shaped hinged plate;

[0028] ​​1001 - first hinge hole, 1002 - second hinge hole, 1003 - third hinge hole, 1004 - fixed hinge hole, 1005 - arcuate oblong hole, 1006 - angle adjustment hole. DETAILED DESCRIPTION

[0029] The preferred embodiments of the present application will be described in more detail below. Although the preferred embodiments of the present application are described below, it is understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein.

[0030] In the present application, the orientation words such as "upper" and "lower" used without the contrary description generally refer to the upper and lower of the device in the normal use state, for example, referring to the figure surface direction of Figure 1 , and "inner" and "outer" refer to relative to the device profile. In addition, the terms "first", "second", "third" are only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0031] The present application provides a diameter-adjustable electric heating device, as shown in Figure 1 , Figure 2 , Figure 3 and Figure 4 , comprising:

[0032] a plurality of fixed units 2 arranged in a circular arc shape, and the inner surface of the circular arc matches the radial outer surface of the cylindrical workpiece 3 to be heated, each fixed unit 2 is in the shape of a cubic frame and is hinged to each other with adjacent fixed units 2, one side of each fixed unit 2 is provided as an inner concave arc surface, which is adapted to the inner surface of the circular arc;

[0033] a plurality of electric heaters 4, each electric heater 4 is arranged on the inner concave arc surface of a fixed unit 2;

[0034] a telescopic movable rack 1 for fixing, supporting and moving the plurality of fixed units 2 arranged in a circular arc shape.

[0035] In the present application, the heating part uses modular fixed units 2 in the form of assembly, which can increase or decrease the number of heating fixed units 2 according to the diameter of the workpiece to be heated, and the fixed units 2 can be hinged to each other, and one side of each fixed unit 2 is provided as an inner concave arc surface to make it present corresponding arc. The fixed unit 2 is modular, simple to operate, and easy to disassemble and assemble, which is conducive to improving work efficiency.

[0036] In the present application, the telescopic mobile rack 1 is reusable, which greatly facilitates the work of preheating the cylinder section.

[0037] In the present application, the telescopic mobile rack 1 has a reasonable structure design, which controls the ratio of the ground area and the height of the rack within the most reasonable range under the precondition of safe use and without tilting, and is convenient to move and adjust.

[0038] Preferably, an inner concave arc surface of each fixed unit 2 is provided with a pair of arc-shaped columns 201 and a pair of supporting crossbars 202, and each supporting crossbar 202 is connected perpendicularly to the pair of arc-shaped columns 201.

[0039] A pair of elastic steel plates 203 are arranged at the middle part of the pair of supporting crossbars 202, and each elastic steel plate 203 is connected perpendicularly to the pair of supporting crossbars 202, and the pair of elastic steel plates 203 are used for fixing an electric heater 4 and making the electric heater 4 adhere to the radial outer surface of the cylindrical workpiece 3 to be heated.

[0040] According to a preferred embodiment of the present application, an opposite outer surface of the inner concave arc surface of each fixed unit 2 is provided with a pair of vertical columns 204 and a pair of reinforcing crossbeams 205, and each reinforcing crossbeam 205 is connected perpendicularly to the pair of vertical columns 204.

[0041] The reinforcing crossbeams 205 of the plurality of fixed units 2 arranged in sequence in the shape of a circular arc are arranged in the shape of an arc line on the outer surface of the circular arc, and the arc line is used as an operation ladder for increasing or decreasing the fixed units 2 or a maintenance ladder for temporarily repairing the electric heater 4.

[0042] According to the present application, one end of the pair of arc-shaped columns 201 is connected to one end of the pair of vertical columns 204 through a pair of long-shaped hinged plates 206.

[0043] The other end of the pair of arc-shaped columns 201 is connected to the other end of the pair of vertical columns 204 through a pair of fan-shaped hinged plates 207.

[0044] The length of the pair of supporting crossbars 202 is equal to the length of the pair of reinforcing crossbeams 205. 。

[0045] Preferably, a first hinged hole 1001, a second hinged hole 1002 and a third hinged hole 1003 are sequentially arranged on each long-shaped hinged plate 206.

[0046] A fixed hinged hole 1004 is arranged at the center point of each fan-shaped hinged plate 207, an arc-shaped long circular hole 1005 is arranged at the middle part, and a plurality of angular adjustment holes 1006 arranged in an arc shape are arranged at the outer arc.

[0047] The first hinge hole 1001 on the long strip-shaped hinge plate 206 of each fixed unit 2 is matched with the fixed hinge hole 1004 of the adjacent fixed unit 2, and is used as a rotation shaft for adjusting the arc by being bolted, the second hinge hole 1002 is correspondingly matched with the long arc-shaped hole 1005 by being bolted, and is used for fastening after the arc is adjusted, and the third hinge hole 1003 is matched with the arc-shaped angle adjustment hole 1006 by being bolted, and is used for adjusting the arc between the adjacent fixed units 2 and being fixed.

[0048] In the application, the fixed units 2 are accurately matched with the required arc by the hinge mode of different hole positions, so that the electric heater 4 is more closely attached to the workpiece to be heated, and the heating efficiency is improved.

[0049] In the application, in addition to meeting the basic requirements of convenient disassembly and assembly of the fixed units 2, after the bolt is fastened, each fixed unit 2 is connected into a rigid whole, and the overall structure rigidity is greatly enhanced. Meanwhile, in the structural design of the fixed unit 2, the temporary ladder function is considered, when the fixed units 2 need to be increased or decreased or the electric heater 4 needs to be temporarily repaired, the operator can use the ladder to go up and down, without the need for separate climbing instruments. This is the most prominent difference between the device and other similar tools.

[0050] According to the application, the telescopic movable rack 1 comprises a height-adjustable ladder-shaped rack, a fixed mechanism 101, and a pair of support adjustment rods 102.

[0051] The height-adjustable ladder-shaped rack comprises a ladder-shaped top surface and a ladder-shaped bottom surface, and the ladder-shaped top surface and the ladder-shaped bottom surface are connected through a plurality of telescopic sleeves 103, and each telescopic sleeve 103 is provided with a fixed pin.

[0052] The height-adjustable ladder-shaped rack is used in the working condition that the relative distance between the two rolling tire turning devices of the cylindrical workpiece is close, and the ladder-shaped short side of the height-adjustable ladder-shaped rack can enter the lower part of the cylinder section.

[0053] In the application, the height-adjustable ladder-shaped rack is used in the working condition that the relative distance between the two rolling tire turning devices of the cylindrical workpiece is close, and the ladder-shaped short side of the height-adjustable ladder-shaped rack can enter the lower part of the cylinder section.

[0054] According to a preferred embodiment of the application, the fixed mechanism 101 is arranged on the ladder-shaped short side of the ladder top surface, is used for fixing a plurality of fixed units 2 arranged in a circular arc shape, and is used for adjusting the angle between the telescopic movable rack 1 and the plurality of fixed units 2 arranged in a circular arc shape.

[0055] Preferably, a pair of support adjusting rods 102 is arranged on both sides of the long side of the trapezoidal top surface, and the pair of support adjusting rods 102 is used to support the plurality of fixed units 2 arranged in a circular arc shape.

[0056] According to the present application, each support adjusting rod 102 is a telescopic sleeve structure, and the support end thereof is a ball head structure.

[0057] Preferably, the telescopic movable rack 1 further comprises four universal wheels 104, a plurality of auxiliary fixing rods;

[0058] The four universal wheels 104 are arranged below the short side and the long side of the trapezoidal bottom surface of the height-adjustable trapezoidal rack, respectively.

[0059] The plurality of auxiliary fixing rods are arranged in the trapezoidal top surface, the trapezoidal bottom surface, and each side of the height-adjustable trapezoidal rack, and the plurality of auxiliary fixing rods are used to form a triangular stable structure on the trapezoidal top surface, the trapezoidal bottom surface, and each side of the height-adjustable trapezoidal rack.

[0060] In the present application, the barrel section can be arranged on one side or both sides according to the need for heating the workpiece, which is conducive to the arrangement of the tool environment, and the site becomes standardized and neat, and the safety degree is greatly improved compared with the previous temporary support.

[0061] The present application will be described in more detail below through a specific embodiment.

[0062] Embodiment 1

[0063] The present embodiment is a diameter-adjustable electric heating device, as shown in Figure 1 、 Figure 2 、 Figure 3 and Figure 4 , comprising:

[0064] a plurality of fixed units 2 arranged in a circular arc shape in sequence, and the inner surface of the circular arc is matched with the radial outer surface of the cylindrical workpiece 3 to be heated, each fixed unit 2 is in the shape of a cubic frame, and is hingedly connected with the adjacent fixed unit 2, one side of each fixed unit 2 is arranged as an inner concave arc surface, which is adapted to the inner surface of the circular arc;

[0065] a plurality of electric heaters 4, each electric heater 4 is arranged on the inner concave arc surface of a fixed unit 2;

[0066] a telescopic movable rack 1 for fixing, supporting and moving the plurality of fixed units 2 arranged in a circular arc shape in sequence;

[0067] a pair of arc-shaped columns 201 and a pair of support crossbars 202 are arranged on the inner concave arc surface of each fixed unit 2, and each support crossbar 202 is perpendicularly connected with the pair of arc-shaped columns 201;

[0068] A pair of elastic steel plates 203 are arranged in the middle of the pair of support crossbars 202, each of the elastic steel plates 203 is connected perpendicularly to the pair of support crossbars 202, the pair of elastic steel plates 203 are used to fix an electric heater 4 and make the heater adhere to the radial outer surface of the cylindrical workpiece 3 to be heated;

[0069] The inner concave arc surface of each fixed unit 2 is provided with a pair of vertical columns 204 and a pair of reinforcing beams 205, each of the reinforcing beams 205 is connected perpendicularly to the pair of vertical columns 204;

[0070] The reinforcing beams 205 of the plurality of fixed units 2 arranged in sequence in the shape of an arc are arranged in the shape of a ladder on the outer surface of the arc, the ladder is used as an operation ladder for increasing or decreasing the fixed units 2 or a maintenance ladder for temporarily repairing the failure of the electric heater 4;

[0071] One end of the pair of arc-shaped columns 201 is connected to one end of the pair of vertical columns 204 through a pair of long-shaped hinged plates 206;

[0072] The other end of the pair of arc-shaped columns 201 is connected to the other end of the pair of vertical columns 204 through a pair of fan-shaped hinged plates 207;

[0073] The length of the pair of support crossbars 202 is equal to the length of the pair of reinforcing beams 205 ；

[0074] The first hinged hole 1001, the second hinged hole 1002 and the third hinged hole 1003 are sequentially arranged on each long-shaped hinged plate 206;

[0075] The center point of each fan-shaped hinged plate 207 is provided with a fixed hinged hole 1004, the middle part is provided with an arc-shaped long circular hole 1005, and the outer arc part is provided with a plurality of angular adjustment holes 1006 arranged in an arc shape;

[0076] The first hinged hole 1001 on one long-shaped hinged plate 206 of each fixed unit 2 cooperates with the fixed hinged hole 1004 of one fan-shaped hinged plate 207 of the adjacent fixed unit 2 and is connected by a bolt, which is used as a rotating shaft for adjusting the arc, the second hinged hole 1002 cooperates with the arc-shaped long circular hole 1005 and is connected by a bolt, which is used for fastening after completing the arc adjustment, and the third hinged hole 1003 cooperates with one of the plurality of angular adjustment holes 1006 arranged in an arc shape and is connected by a bolt, which is used for adjusting the arc between the adjacent fixed units 2 and fixing;

[0077] The telescopic movable rack 1 includes a height-adjustable trapezoidal rack, a fixing mechanism 101, and a pair of support adjustment bars 102;

[0078] The height-adjustable trapezoidal rack comprises a trapezoidal top surface and a trapezoidal bottom surface, and the trapezoidal top surface and the trapezoidal bottom surface are connected through a plurality of telescopic sleeves 103, each of which is provided with a fixed pin;

[0079] The height-adjustable trapezoidal rack is used in the working condition that the distance between two rolling tire-changing devices is relatively short, and the trapezoidal short side of the height-adjustable trapezoidal rack can enter the lower part of the cylinder section;

[0080] The trapezoidal top surface is provided with a fixing mechanism 101 for fixing a plurality of fixing units 2 arranged in a circular arc shape, and for adjusting the angle between the telescopic movable rack 1 and the plurality of fixing units 2 arranged in a circular arc shape;

[0081] The trapezoidal long side of the trapezoidal top surface is respectively provided with a pair of support adjusting rods 102 for supporting the plurality of fixing units 2 arranged in a circular arc shape;

[0082] Each of the support adjusting rods 102 is a telescopic sleeve structure, and the support end thereof is a ball head structure;

[0083] The telescopic movable rack 1 further comprises four universal wheels 104 and a plurality of auxiliary fixing rods;

[0084] The four universal wheels 104 are respectively arranged below the trapezoidal short side and the long side of the bottom surface of the height-adjustable trapezoidal rack;

[0085] The plurality of auxiliary fixing rods are arranged in the trapezoidal top surface, the trapezoidal bottom surface and each side of the height-adjustable trapezoidal rack, and the plurality of auxiliary fixing rods are used to form a triangular stable structure in the trapezoidal top surface, the trapezoidal bottom surface and each side of the height-adjustable trapezoidal rack.

[0086] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. An electrically heated device with adjustable diameter, characterized in that, The application relates to a heating device for a cylindrical workpiece. The application comprises: a plurality of fixing units arranged in a circular arc shape, and the inner surface of the circular arc is matched with the radial outer surface of a cylindrical workpiece to be heated, each fixing unit is in a cuboid frame shape, and is hingedly connected with adjacent fixing units, one side of each fixing unit is provided with an inner concave arc surface matched with the inner surface of the circular arc; a plurality of electric heaters, each electric heater is arranged on the inner concave arc surface of a fixing unit; a telescopic moving rack used for fixing, supporting and moving the plurality of fixing units arranged in a circular arc shape; the inner concave arc surface of each fixing unit is provided with a pair of arc-shaped vertical columns and a pair of supporting horizontal rods, each supporting horizontal rod is perpendicularly connected with the pair of arc-shaped vertical columns; the middle part of the pair of supporting horizontal rods is provided with a pair of elastic steel plates, each elastic steel plate is perpendicularly connected with the pair of supporting horizontal rods, the pair of elastic steel plates are used for fixing an electric heater and making the electric heater closely contact with the radial outer surface of the cylindrical workpiece to be heated; the opposite outer vertical surfaces of the inner concave arc surface of each fixing unit are provided with a pair of vertical columns and a pair of reinforcing horizontal beams, each reinforcing horizontal beam is perpendicularly connected with the pair of vertical columns; the reinforcing horizontal beams of the plurality of fixing units arranged in a circular arc shape are arranged in an arc-shaped ladder on the outer surface of the circular arc, and the ladder is used as an operation ladder for increasing or decreasing the fixing units or a maintenance ladder for temporarily repairing the electric heater fault; one end of the pair of arc-shaped vertical columns is connected with one end of the pair of vertical columns through a pair of long strip-shaped hinge plates; the other end of the pair of arc-shaped vertical columns is connected with the other end of the pair of vertical columns through a pair of fan-shaped hinge plates; the lengths of the pair of supporting horizontal rods and the pair of reinforcing horizontal beams are equal; a first hinge hole, a second hinge hole and a third hinge hole are sequentially arranged on each long strip-shaped hinge plate; a fixed hinge hole is arranged at the center point of each fan-shaped hinge plate, an arc-shaped long circular hole is arranged at the middle part, and a plurality of angular adjustment holes arranged in an arc shape are arranged at the outer arc; 2. The apparatus of claim 1, wherein, the first hinge hole of one long strip-shaped hinge plate of each fixing unit is matched with the fixed hinge hole of one fan-shaped hinge plate of an adjacent fixing unit and is connected through a bolt, and is used as a rotating shaft for adjusting the arc degree; the second hinge hole is correspondingly matched with the arc-shaped long circular hole and is connected through a bolt, and is used for fastening after the arc degree is adjusted; the third hinge hole is matched with the plurality of angular adjustment holes arranged in an arc shape and is connected with one of the angular adjustment holes through a bolt, and is used for adjusting the arc degree between the adjacent fixing units and fixing. The telescopic moving rack comprises a height-adjustable ladder-shaped rack, a fixing mechanism and a pair of supporting adjustment rods. The height-adjustable ladder-shaped rack comprises a ladder-shaped top surface and a ladder-shaped bottom surface, the ladder-shaped top surface and the ladder-shaped bottom surface are connected through a plurality of telescopic sleeves, and each telescopic sleeve is provided with a fixed pin.

3. The apparatus of claim 2, wherein, The height-adjustable ladder-shaped rack is used under the working condition that the relative distance between two rolling tire turning devices of the cylindrical workpiece is short, and the short side of the ladder-shaped top surface of the height-adjustable ladder-shaped rack can enter the lower part of the cylinder section. The short side of the ladder-shaped top surface is provided with the fixing mechanism, the fixing mechanism is used for fixing the plurality of fixing units arranged in a circular arc shape, and is used for adjusting the angle between the telescopic moving rack and the plurality of fixing units arranged in a circular arc shape.

4. The apparatus of claim 3, wherein, The trapezoidal long side of the trapezoidal top surface is respectively provided with a pair of support adjusting rods for supporting a plurality of fixed units arranged in a circular arc shape.

5. The apparatus of claim 4, wherein, Each support adjusting rod is a telescopic sleeve structure, and the support end thereof is a ball head structure.

6. The apparatus of claim 5, wherein, The telescopic moving rack further comprises four universal wheels and a plurality of auxiliary fixing rods. The four universal wheels are respectively arranged below the trapezoidal short side and the long side of the bottom surface of the height-adjustable trapezoidal rack. The plurality of auxiliary fixing rods are arranged in the trapezoidal top surface, the trapezoidal bottom surface and each side of the height-adjustable trapezoidal rack, and are used to form a triangular stable structure on the trapezoidal top surface, the trapezoidal bottom surface and each side of the height-adjustable trapezoidal rack.

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