Anti-corrosion electric heater

Abstract

The utility model discloses an anti-corrosion electric heater, which comprises a cylinder body, an upper end cover, an electric appliance box and a heating group, and is characterized in that the upper end cover can be detachably connected to the upper end surface of the cylinder body, and a plurality of pairs of first limiting holes are formed in the upper end cover; the electric appliance box is detachably connected to the upper end cover, and multiple pairs of first connecting holes are formed in the inner bottom of the electric appliance box; the heating group comprises a retainer and a plurality of electric heating elements, a plurality of ventilation holes and a plurality of pairs of second limiting holes are formed in the limiting plates, and the two ends of the electric heating elements sequentially penetrate through a pair of second limiting holes, a pair of first limiting holes and a pair of first connecting holes in the limiting plates; the two ends of the electric heating element extend into an inner cavity of the electric appliance box and are connected with the electric appliance box through connecting pieces. The two ends of the electric heating element are used for being connected with a power source. The upper end cover and the cylinder body are separated, and the electric appliance box and the connecting piece are separated, so that the electric heating element can be replaced and maintained conveniently and quickly.

Description

Technical Field

[0001] The utility model relates to the technical field of gas treatment equipment, in particular to an anti-corrosion electric heater. Background Art

[0002] In the treatment of carbon dioxide, it includes drying, filtering and heating the carbon dioxide. Drying is to remove the moisture in the gas, filtering means filtering out the dust and other odor gases in the gas to improve the purity of carbon dioxide, and heating means heating the gas to a suitable temperature for subsequent treatment of the gas. At present, electric heating elements are often used to heat carbon dioxide gas. Due to factors such as voltage fluctuations and harsh use environments, the electric heating elements will be damaged, and the densely arranged electric heating elements are not easy to replace, resulting in difficulties in maintenance and a long maintenance time. Content of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides an anti-corrosion electric heater, which is convenient for maintenance.

[0004] An anti-corrosion electric heater according to an embodiment of the utility model includes a cylinder body, an upper end cover, an electrical box and a heating group. An air inlet pipe and an air outlet pipe are respectively arranged at the upper and lower ends of the cylinder body; the upper end cover is detachably connected to the upper end surface of the cylinder body, and a plurality of pairs of first limiting holes are arranged on the upper end cover; the electrical box is detachably connected to the upper end cover, and a plurality of pairs of first connecting holes are arranged on the inner bottom of the electrical box; the heating group includes a holder and a plurality of electric heating elements. The holder includes a plurality of parallel support rods and a plurality of limiting plates sleeved on the support rods. The support rods pass through the inner cavity of the cylinder body and the upper ends of the support rods are connected to the upper end cover. A plurality of ventilation holes and a plurality of pairs of second limiting holes are arranged on the limiting plates. The two ends of the electric heating element sequentially pass through a pair of the second limiting holes, a pair of the first limiting holes and a pair of the first connecting holes on a plurality of limiting plates, and the two ends of the electric heating element extend into the inner cavity of the electrical box and are connected to the electrical box through connecting pieces. The two ends of the electric heating element are used for connecting to a power supply.

[0005] It has at least the following beneficial effects:

[0006] The intake pipe conveys the carbon dioxide gas to be heated from the outside into the inner cavity of the cylinder body. The electric heating element inside the cylinder body heats the carbon dioxide gas, and the heated carbon dioxide gas is discharged outside the cylinder body through the outlet pipe. The support rods and the limiting plates of the cage play a role in limiting the electric heating element, avoiding interference between the electric heating elements and between the electric heating element and the inner wall of the cylinder body, thereby effectively avoiding damage to the electric heating element and ensuring the normal operation of the electric heating element. By disassembling the upper end cover and the cylinder body, the upper end cover, the electrical box and the heating group can be lifted, the heating group can be pulled out of the cylinder body, and then the electrical box and the connecting piece can be disassembled, so that the electric heating element can be withdrawn from a pair of the first connection holes, a pair of the first limiting holes and a pair of the second limiting holes on several limiting plates in sequence, completing the disassembly of the electric heating element. Fetch a complete electric heating element and operate in reverse according to the above steps to complete the replacement and repair of the electric heating element, which is convenient and fast.

[0007] According to some embodiments of the present invention, the electric heating element is a U-shaped electric heating tube, the connecting piece is a first nut, the end of the electric heating element is provided with a threaded section, the first connection hole is a stepped through hole that is smaller at the top and larger at the bottom, the end of the electric heating element abuts against the inner wall of the first connection hole, and the threaded section extends into the inner cavity of the electrical box and is threadedly connected to the connecting piece, and the connecting piece abuts against the upper surface of the side wall of the first connection hole to lock the end of the electric heating element on the electrical box.

[0008] According to some embodiments of the present invention, a wiring post is connected to the upper end of the threaded section, and two second nuts are threadedly connected to the wiring post. The two second nuts are used to clamp a wiring terminal, and the wiring terminal is used to connect to a power supply.

[0009] According to some embodiments of the present invention, a connecting post is provided in the inner bottom of the electrical box in the area corresponding to the first connection hole, and the first connection hole penetrates through the inner bottom of the electrical box and the connecting post.

[0010] According to some embodiments of the present invention, a plurality of threaded areas are provided on the support rod, and two third nuts are threadedly connected to the threaded areas, and the limiting plate is clamped between the two third nuts.

[0011] According to some embodiments of the present invention, the limiting plate is in a disc shape, the limiting plate is evenly divided into four fan-shaped areas, and a plurality of the second limiting holes on adjacent two fan-shaped areas are symmetrically arranged.

[0012] According to some embodiments of the present invention, on each fan-shaped area, the planes where a plurality of the electric heating elements are located are parallel to each other.

[0013] According to some embodiments of the present utility model, the cross-section of the ventilation hole is square, a plurality of the ventilation holes are parallel to each other, the length direction of the ventilation hole is parallel to the direction of each row of the electric heating elements, and rows of the second limiting holes are arranged between two adjacent ventilation holes.

[0014] According to some embodiments of the present utility model, the connection line of a pair of the second limiting holes forms an angle with the length direction of the ventilation hole.

[0015] According to some embodiments of the present utility model, a heat insulation layer is provided on the cylinder body.

[0016] The additional aspects and advantages of the present utility model will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present utility model. Description of the Drawings

[0017] The following further describes the present utility model in conjunction with the drawings and embodiments, where:

[0018] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;

[0019] Figure 2 is a schematic cross-sectional structural diagram of an embodiment of the present utility model;

[0020] Figure 3 is Figure 2 a partial enlarged schematic diagram of part A in

[0021] Figure 4 is Figure 2 a partial enlarged schematic diagram of part B in

[0022] Figure 5 is a schematic structural diagram of the limiting plate of an embodiment of the present utility model;

[0023] Reference Numerals in the Drawings:

[0024] Cylinder body 100; Inlet pipe 110; Outlet pipe 120; Hanging ear 130; Exhaust pipe 140;

[0025] Upper end cover 200;

[0026] Electrical box 300; First connection hole 310;

[0027] Holder 400; Support rod 410; Limiting plate 420; Ventilation hole 421; Second limiting hole 422; Second connection hole 423; Third nut 430;

[0028] Electric heating element 500; Threaded section 510; Terminal 520;

[0029] Connector 600;

[0030] The second nut 700. Specific embodiments

[0031] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0032] In the description of the present invention, it should be understood that with regard to the orientation description, such as the upper, lower, front, rear, left, right, etc., the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0033] In the description of the present invention, "a plurality of" refers to more than two, and "more than" includes the number itself. If the first and second are described, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0034] In the description of the present invention, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0035] Referring to Figure 1 and Figure 2 , the present invention discloses an anti-corrosion electric heater, which includes a cylinder body 100, an upper end cover 200, an electrical box 300 and a heating group.

[0036] An air inlet pipe 110 and an air outlet pipe 120 are respectively provided at the upper and lower ends of the cylinder body 100. The cylinder body 100 has an inner cavity, and both the air inlet pipe 110 and the air outlet pipe 120 are communicated with the inner cavity of the cylinder body 100. The air inlet pipe 110 is used to transport the carbon dioxide gas to be heated outside into the inner cavity of the cylinder body 100, and the air outlet pipe 120 is used to output the carbon dioxide gas in the inner cavity of the cylinder body 100 outside the cylinder body 100.

[0037] The upper end cover 200 is detachably connected to the upper end surface of the cylinder body 100, and a plurality of pairs of first limiting holes are provided on the upper end cover 200. It should be understood that "pair" means the meaning of two features used in combination.

[0038] Referring to Figure 2 and Figure 3, the electrical box 300 is detachably connected to the upper end cover 200, and a plurality of pairs of first connection holes 310 are provided on the inner bottom of the electrical box 300.

[0039] Referring to Figure 2 and Figure 4 , the heating group includes a cage 400 and a plurality of electric heating elements 500. The cage 400 includes a plurality of parallel support rods 410 and a plurality of limiting plates 420 sleeved on the support rods 410. The support rods 410 penetrate through the inner cavity of the cylinder 100, and the upper ends of the support rods 410 are connected to the upper end cover 200. Refer to Figure 5 , a plurality of ventilation holes 421 and a plurality of pairs of second limiting holes 422 are provided on the limiting plates 420. The two ends of the electric heating element 500 sequentially penetrate through a pair of second limiting holes 422, a pair of first limiting holes and a pair of first connection holes 310 on a plurality of limiting plates 420. The two ends of the electric heating element 500 extend into the inner cavity of the electrical box 300 and are connected to the electrical box 300 through a connecting member 600. The two ends of the electric heating element 500 are used for connecting to a power source.

[0040] The intake pipe 110 conveys the carbon dioxide gas to be heated in the outside world into the inner cavity of the cylinder 100. The electric heating element 500 in the cylinder 100 heats the carbon dioxide gas, and the heated carbon dioxide gas is discharged out of the cylinder 100 through the outlet pipe 120. The support rods 410 and the limiting plates 420 of the cage 400 play a role in limiting the electric heating element 500, avoiding interference between the electric heating element 500 and the electric heating element 500 and the inner wall of the cylinder 100, thereby effectively avoiding damage to the electric heating element 500 and ensuring the normal operation of the electric heating element 500.

[0041] Separating the upper end cover 200 and the cylinder 100, the upper end cover 200, the electrical box 300 and the heating group can be lifted, the heating group can be pulled out of the cylinder 100, and then the electrical box 300 and the connecting member 600 can be separated. Then, the electric heating element 500 can be withdrawn from a pair of first connection holes 310, a pair of first limiting holes and a pair of second limiting holes 422 on a plurality of limiting plates 420 in sequence, completing the disassembly of the electric heating element 500. Fetching a complete electric heating element 500 and operating in the reverse order according to the above steps can complete the replacement and repair of the electric heating element 500, which is convenient and fast.

[0042] Referring to Figure 2 , in some of the embodiments, the electric heating element 500 is a U-shaped electric heating tube, and the U-shaped electric heating tube has two ends.

[0043] Referring to Figure 3, the end of the electric heating element 500 is provided with a threaded section 510. The connecting piece 600 is a first nut, and the first connecting hole 310 is a stepped through hole that is smaller at the top and larger at the bottom. The end of the electric heating element 500 abuts against the inner wall of the first connecting hole 310, and the threaded section 510 extends into the inner cavity of the electrical box 300 and is threadedly connected to the connecting piece 600. The connecting piece 600 abuts against the upper surface of the side wall of the first connecting hole 310. Under the combined action of the inner wall of the first connecting hole 310 and the connecting piece 600, the end of the electric heating element 500 can be locked on the electrical box 300.

[0044] The specific operation is as follows: insert the threaded section 510 into the first connecting hole 310 in the direction towards the electrical box 300. The end of the electric heating element 500 abuts against the inner wall of the first connecting hole 310. After the threaded section 510 passes through the first connecting hole 310, it extends into the inner cavity of the electrical box 300. Then, screw the connecting piece 600 onto the threaded section 510 in the electrical box 300 until the connecting piece 600 abuts against the upper surface of the side wall of the first connecting hole 310. When it is necessary to remove the electric heating element 500, unscrew the connecting piece 600 and withdraw the end of the electric heating element 500 and the threaded section 510 from the first connecting hole 310 in the direction away from the electrical box 300.

[0045] See Figure 3 , in some of these embodiments, a terminal post 520 is connected to the upper end of the threaded section 510. The terminal post 520 is threadedly connected to two second nuts 700. The two second nuts 700 are used to clamp a terminal, and the terminal is used to connect to a power source. By turning the two second nuts 700, it is possible to easily clamp and release the terminal connected to the power source, improving the speed and reliability of wiring the electric heating element 500.

[0046] One end of the electric heating element 500, the threaded section 510, and the terminal post 520 are coaxially arranged. It can be imagined that two washers are sleeved on the terminal post 520. The two washers are located between the two second nuts 700. The two second nuts 700 respectively abut against the upper and lower surfaces of the terminal through the two washers, increasing the contact area, reducing the resistance at the connection point, avoiding a decrease in the conductivity at the wiring point, and improving the quality of the wiring.

[0047] See Figure 3 , in some of these embodiments, a connecting post is provided in the area of the inner bottom of the electrical box 300 corresponding to the first connecting hole 310. The first connecting hole 310 penetrates through the inner bottom of the electrical box 300 and the connecting post. The setting of the connecting post makes the length of the first connecting hole 310 longer, and there is a large enough contact area between the inner wall of the first connecting hole 310 and the end of the electric heating element 500, improving the stability of the connection between the electric heating element 500 and the electrical box 300. Moreover, the connecting post makes the connecting piece 600 protrude from the inner bottom of the electrical box 300, facilitating the operation of the connecting piece 600.

[0048] It can be understood that the connecting column is columnar. The lower end of the connecting column is connected to the inner bottom of the electrical box 300 by welding, or the lower end of the connecting column is connected to the inner bottom of the electrical box 300 by threaded connection. The first connecting hole 310 penetrates through the connecting column, and the first connecting hole 310 is located at the central axis of the connecting column. The first connecting hole 310 has two upper and lower sections. One section of the first connecting hole 310 penetrates through the connecting column, and the other section of the first connecting hole 310 penetrates through the inner bottom of the electrical box 300. The diameter of one section of the first connecting hole 310 is smaller than the diameter of the other section of the first connecting hole 310, or the diameter of the upper section of one section of the first connecting hole 310 is smaller than the diameter of the lower section of one section of the first connecting hole 310, and the diameter of the lower section of one section of the first connecting hole 310 is equal to the diameter of the other section of the first connecting hole 310.

[0049] In some of these embodiments, the support rod 410 is provided with an external thread structure at the position corresponding to the limit plate 420. Two third nuts 430 are connected to the external thread structure, and the limit plate 420 is clamped between the two third nuts 430.

[0050] When assembling the cage 400, first connect the support rod 410 to the upper end cover 200, then screw on a third nut 430 on the external thread structure, then insert the support rod 410 into the second connecting hole 423 of the limit plate 420 until the limit plate 420 abuts against the third nut 430, and then screw on another third nut 430 on the external thread structure until the two third nuts 430 tightly clamp the limit plate 420, thereby completing the connection between the support rod 410 and the limit plate 420.

[0051] Specifically, refer to Figure 5 , the limit plate 420 is provided with four second connecting holes 423. The four second connecting holes 423 are annularly and evenly distributed on the limit plate 420. The number of support rods 410 is four, and the number of limit plates 420 is three. The support rods 410 pass through the second connecting holes 423 on the three limit plates 420. The upper ends of the four support rods 410 are connected to the upper end cover 200 by threaded connection, and the four support rods 410 are annularly and evenly distributed.

[0052] In some of these embodiments, the inner cavity of the cylinder 100 is a columnar space, the limit plate 420 is disc-shaped, and the outer diameter of the limit plate 420 is matched with the diameter of the inner cavity of the cylinder 100.

[0053] Refer to Figure 5, the limiting plate 420 is evenly divided into four fan-shaped regions, and a plurality of second limiting holes 422 on adjacent two fan-shaped regions are symmetrically arranged. The plurality of heating elements 500 are divided into four groups, and the heating elements 500 in adjacent two groups are symmetrically arranged. After the limiting plate 420 rotates 180° in the horizontal plane, the limiting plate 420 can still be sleeved on all the heating elements 500 without changing the positions of the heating elements 500.

[0054] In some of these embodiments, on each fan-shaped region, the planes where the plurality of heating elements 500 are located are parallel to each other, avoiding the staggered layout of the heating elements 500, which is convenient for the installation and removal of the heating elements 500.

[0055] See Figure 5 , in some of these embodiments, the cross-section of the ventilation hole 421 is square, a plurality of ventilation holes 421 are parallel to each other, the length direction of the ventilation hole 421 is parallel to the trend of each row of heating elements 500, and the row of second limiting holes 422 is arranged between two adjacent ventilation holes 421, so that carbon dioxide gas can pass through both sides of the heating element 500, thereby heating the carbon dioxide gas in time. See Figure 5 , two second limiting holes 422 connected by a dotted line on the limiting plate 420 are a pair of second limiting holes 422.

[0056] In some of these embodiments, the connection line of a pair of second limiting holes 422 forms an angle with the length direction of the ventilation hole 421. Compared with the scheme where the number of second limiting holes 422 in each row is equal to the number of second limiting holes 422 in each column and the length of each row of second limiting holes 422 is equal to the length of each column of second limiting holes 422, in the case where the connection lines of a pair of second limiting holes 422 are equal, the scheme of the present application is convenient for arranging more heating elements 500.

[0057] It can be understood that the planes where each pair of the second limiting holes 422 is located are all parallel to the front-back direction (longitudinal direction) or the left-right direction (transverse direction). Multiple pairs of the second limiting holes 422 are distributed vertically and horizontally in a rectangular shape, and multiple pairs of the second limiting holes 422 are symmetrically arranged in the front-back direction and the left-right direction. That is, in both the longitudinal and transverse directions, the distance between two adjacent second limiting holes 422 is equal, and the number of the second limiting holes 422 in both the longitudinal and transverse directions is a positive even number. This can enable the limiting plate 420 to still be sleeved on all the heating elements 500 without changing the positions of the heating elements 500 after the limiting plate 420 rotates 90° in the horizontal plane each time, facilitating the installation of the limiting plate 420 and the cooperation between the limiting plate 420 and the heating elements 500. Moreover, it can make the length directions of the ventilation holes 421 of two adjacent limiting plates 420 perpendicular to each other. When the carbon dioxide gas passes through the ventilation holes 421 on two adjacent limiting plates 420, the carbon dioxide gas sweeps over multiple heating elements 500, and the contact between the carbon dioxide gas and the heating elements 500 is more sufficient.

[0058] See Figure 5 , a relatively large cavity is formed between the four heating elements 500 in the center, and a temperature sensor can be arranged in the cavity.

[0059] See Figure 2 , the electrical box 300 includes a circular shell, an upper cover and a lower cover. The upper cover and the upper end of the circular shell are detachably connected, such as by fasteners. The lower cover and the lower end of the circular shell can be connected by welding. The circular shell, the upper cover and the lower cover enclose a chamber, and the lower cover is the bottom wall of the electrical box 300.

[0060] The electrical box 300 and the upper end cover 200 can be connected by a fastener connection method (not shown in the figure).

[0061] Specifically, the upper end cover 200 and the cylinder body 100 are connected by a flange and fasteners. The fasteners include a bolt and a nut that cooperate with each other.

[0062] In some of the embodiments, a heat insulation layer (not shown in the figure) is provided on the cylinder body 100. The heat insulation layer can reduce the heat dissipated through the cylinder body 100, which is beneficial to energy conservation.

[0063] See Figure 1 and Figure 2 , a lifting lug 130 and an exhaust pipe 140 are provided on the cylinder body 100. The lifting lug 130 can be conveniently connected to the equipment therein to lift the electric heater. The exhaust pipe 140 is communicated with the inner cavity of the cylinder body 100. Through the exhaust pipe 140, it is possible to emergently discharge carbon dioxide gas, relieve pressure, and discharge the residual impurities and foreign matters in the cylinder body 100.

[0064] The outer walls of the cylinder body 100, the intake pipe 110, the outlet pipe 120, the exhaust pipe 140, and the electrical box 300 are all coated with an anti-corrosion and rust-proof layer to improve the service life of the entire electric heater.

[0065] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0066] Of course, the present invention is not limited to the above embodiments. Those skilled in the art can also make equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent variations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. An anti-corrosion electric heater, characterized in that: include: The cylinder (100) has an air inlet pipe (110) and an air outlet pipe (120) at its upper and lower ends respectively; An upper end cover (200) is detachably connected to the upper end surface of the cylinder (100), and a plurality of pairs of first limiting holes are provided on the upper end cover (200); An electrical box (300) is detachably connected to the upper end cover (200), and a plurality of pairs of first connection holes (310) are provided on the inner bottom of the electrical box (300); A heating group comprises a retaining frame (400) and a plurality of electric heating elements (500), wherein the retaining frame (400) comprises a plurality of mutually parallel support rods (410) and a plurality of limiting plates (420) sleeved on the support rods (410), wherein the support rods (410) are inserted into the inner cavity of the cylinder (100) and the upper ends of the support rods (410) are connected to the upper end cover (200), and the limiting plates (420) are provided with a plurality of ventilation holes (421) and a plurality of For the second limiting holes (422), the two ends of the electric heating element (500) are sequentially penetrated through a pair of the second limiting holes (422), a pair of the first limiting holes and a pair of the first connecting holes (310) on a plurality of limiting plates (420), and the two ends of the electric heating element (500) extend into the inner cavity of the electrical box (300) and are connected to the electrical box (300) through a connecting piece (600), and the two ends of the electric heating element (500) are used to be connected to a power source.

2. The anti-corrosion electric heater according to claim 1, characterized in that: The electric heating element (500) is a U-shaped electric heating tube, the connecting piece (600) is a first nut, the end of the electric heating element (500) is provided with a threaded section (510), the first connecting hole (310) is a stepped through hole with a smaller top and a larger bottom, the end of the electric heating element (500) abuts against the inner wall of the first connecting hole (310), the threaded section (510) extends into the inner cavity of the electrical box (300) and is threadedly connected to the connecting piece (600), and the connecting piece (600) abuts against the upper surface of the side wall of the first connecting hole (310) to lock the end of the electric heating element (500) on the electrical box (300).

3. The anti-corrosion electric heater according to claim 2, characterized in that: The upper end of the threaded section (510) is connected to a terminal post (520), and the terminal post (520) is threadedly connected to two second nuts (700). The two second nuts (700) are used to clamp a terminal, and the terminal is used to connect to a power source.

4. An anti-corrosion electric heater according to claim 2 or 3, characterized in that: The inner bottom of the electrical appliance box (300) is provided with a connecting column in an area corresponding to the first connecting hole (310), and the first connecting hole (310) passes through the inner bottom of the electrical appliance box (300) and the connecting column.

5. The anti-corrosion electric heater according to claim 1, characterized in that: The support rod (410) is provided with a plurality of threaded areas, the threaded areas are threadedly connected to two third nuts (430), and the limiting plate (420) is sandwiched between the two third nuts (430).

6. The anti-corrosion electric heater according to claim 1 or 5, characterized in that: The limiting plate (420) is disc-shaped, and the limiting plate (420) is evenly divided into four sector-shaped areas, and the plurality of second limiting holes (422) on two adjacent sector-shaped areas are symmetrically arranged.

7. The anti-corrosion electric heater according to claim 6, characterized in that: In each of the fan-shaped areas, the planes where the plurality of electric heating elements (500) are located are parallel to each other.

8. The anti-corrosion electric heater according to claim 7, characterized in that: The cross section of the ventilation holes (421) is square, the plurality of ventilation holes (421) are parallel to each other, the length direction of the ventilation holes (421) is parallel to the direction of each row of the electric heating elements (500), and the second limiting holes (422) in a row are arranged between two adjacent ventilation holes (421).

9. The anti-corrosion electric heater according to claim 8, characterized in that: A line connecting a pair of the second limiting holes (422) forms an angle with the length direction of the ventilation hole (421).

10. The anti-corrosion electric heater according to claim 1, characterized in that: A heat insulation layer is provided on the cylinder (100).

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