Crystallizer for metal casting

Abstract

The crystallizer for metal casting comprises a crystallizer body and a base, the crystallizer body comprises a shell and a crystallization barrel, the axis of the shell and the axis of the crystallization barrel are both horizontally arranged, and a water inlet pipe and a water outlet pipe are installed on the two opposite sides of the shell correspondingly; an injection pipe is mounted at the upper end of one side, close to the water inlet pipe, of the crystallization barrel; a driving motor is mounted at the upper end of one side, close to the injection pipe, of the base; the crystallizer body is horizontally arranged, and the driving motor is used for driving the crystallizer body to horizontally rotate, so that molten metal in the crystallizer body is extruded under the action of centrifugal force, bubbles in the molten metal are extruded out, a good defoaming effect is achieved, and the crystallization quality is improved; and at the moment, the crystallizer body is continuously driven by the driving motor to horizontally rotate, so that the crystal in the crystallizer body slides outwards under the action of centrifugal force, and smooth demolding is facilitated.

Description

Technical Field

[0001] The present invention relates to a metal crystallizer, in particular to a metal casting crystallizer applied in the field of metal casting. Background Art

[0002] The crystallizer is an important component in metal casting. The molten metal injected into the crystallizer is cooled by the wall of the crystallizer and then solidified. During this process, there is a complex dynamic heat exchange process between the molten metal and the crystallizer. Especially for solid-liquid bimetallic composite casting production, the crystallizer is required to have a good cooling effect to ensure product quality.

[0003] For example, the specification of patent application number CN202222257344.3 discloses a crystallizer for metal casting, including an outer shell and a mold base and a water-sealing cap installed at both ends of the outer shell; a cooling inner tube is provided between the mold base and the water-sealing cap, and a cooling cavity is formed between the cooling inner tube and the outer shell; the mold base includes a connecting section and an installation section, and a matching section and a tapered section are provided in the inner hole of the mold base; the connecting section is inserted into the outer shell, and the matching section matches the cooling inner tube, and a cooling groove is provided at one end of the mold base on the inner side of the outer shell, and the cooling groove is connected to the cooling cavity, and the cooling groove extends from the inside to the outside. The length is greater than or equal to the length of the matching section. The crystallizer has higher cooling efficiency and better cooling effect, can adapt to higher production rates, has higher production efficiency, and can effectively improve the product eccentricity problem in the solid-liquid bimetallic composite casting process.

[0004] Based on the above search and in combination with the prior art, it is found that in the process of injecting molten metal into the crystallizer, bubbles are easily generated in the existing crystallizer for metal casting, and the bubbles are difficult to eliminate, resulting in reduced quality of metal parts after crystallization; in addition, the cooling chamber of the existing crystallizer is generally a single straight cylinder. When water flows through, the cooling water temperature on the side close to the molten metal is always relatively high, while the cooling water temperature on the side away from the molten metal is always relatively low, resulting in low crystallization efficiency. Therefore, a crystallizer for metal casting is proposed to improve the above problems. Summary of the invention

[0005] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is that bubbles are easily generated during the process of injecting molten metal into the crystallizer, and the bubbles are difficult to eliminate, resulting in reduced quality of the metal parts after crystallization; and the cooling chamber of the existing crystallizer is generally a single straight cylinder, and the crystallization efficiency is low.

[0006] In order to solve the above problems, the present invention provides a crystallizer for metal casting, comprising a crystallizer body and a base: The crystallizer body comprises an outer shell and a crystallization cylinder coaxially sleeved on the inner side of the outer shell; The axes of the shell and the crystallization cylinder are both arranged horizontally; A water inlet pipe is installed on one side of the shell, a water outlet pipe is installed on the other side of the shell, and an injection pipe is installed on the upper end of the crystallization tube near the water inlet pipe; A driving motor is installed on the upper end of the base close to the injection pipe, and the output end of the driving motor is vertically fixed to the bottom end of the shell; The end of the crystallization cylinder away from the injection pipe is arranged to be open, and a sealing cover is threadedly connected to the open end.

[0007] In the above-mentioned crystallizer for metal casting, the crystallizer body is horizontally arranged and driven by a driving motor to rotate horizontally, so that the molten metal inside the crystallizer body is squeezed under the action of centrifugal force, thereby squeezing out the bubbles in the molten metal, playing a good defoaming role, thereby improving the crystallization quality. In addition, after crystallization, the sealing cover is loosened to separate the sealing cover from the crystal. At this time, the driving motor is continued to drive the crystallizer body to rotate horizontally, so that the crystal inside the crystallizer body slides outward under the action of centrifugal force, which is convenient for smooth demolding.

[0008] As a further supplement to the present application, a plurality of heat sinks are fixed to the outer surface of the crystallization cylinder at equal intervals along its length direction; the heat sinks can increase the contact area with the cooling water, thereby further improving the cooling effect.

[0009] As a further supplement to the present application, the heat sink is arranged in a ring shape and is attached to the inner wall of the outer shell. A plurality of water holes are arranged on the heat sink. The heat sink is supported between the outer shell and the crystallization cylinder, which can enhance the overall strength of the outer shell.

[0010] As a further supplement to the present application, the plurality of water holes are arranged in two rings and are both arranged concentrically with the heat dissipation plate; The multiple water holes are all arranged as inclined holes, and the multiple water holes close to the center of the circle are inclined along the water flow direction toward the side away from the center of the circle, and the multiple water holes away from the center of the circle are inclined along the water flow direction toward the side close to the center of the circle; the two groups of inclined water holes can make the cooling water close to the crystallization cylinder and the cooling water away from the crystallization cylinder mixed with each other by convection, give full play to the cooling effect of the cooling water, and accelerate the crystallization speed.

[0011] As a further supplement to the present application, a plurality of first water conduits and a plurality of second water conduits are fixed to one side end of the heat dissipation plate close to the water outlet pipe; The plurality of first water guide pipes correspond to the plurality of water holes away from the center of the circle one by one and are arranged coaxially with the water holes; The multiple second water pipes correspond one by one to the multiple water holes near the center of the circle and are arranged coaxially with the water holes; the first water pipe and the second water pipe can enhance the convection intensity of the cooling water close to the crystallization cylinder and the cooling water away from the crystallization cylinder, and at the same time can further increase the contact area with the cooling water to improve the cooling effect.

[0012] As another improvement of the present application, a first water storage tank is provided on the upper side of the crystallizer body, the first water storage tank is fixed to the base through a support frame, a connected refrigerator is installed on the first water storage tank, and the refrigerator is connected to the water inlet pipe; A second water tank is installed on the upper end of the side of the base close to the driving motor, a side end of the second water tank is fixedly connected to a third water tank, a side of the third water tank away from the second water tank is fixedly connected to a circulation pipe, and a return pipe is connected between the circulation pipe and the first water tank; The end of the water outlet pipe away from the shell extends to the inner side of the second water storage tank, a pumping assembly is installed on the inner side of the circulation pipe, and a transmission structure is installed between the output end of the driving motor and the pumping assembly.

[0013] As another improved supplement of the present application, the pumping assembly includes a transmission rod, a fixing block and a piston; The transmission rod is vertically rotatably mounted on the third water storage tank, and the bottom end of the transmission rod is connected to the transmission structure; The fixed block is fixed to the inner side of the circulation pipe, the piston is located on the upper side of the fixed block and is installed on the inner side of the circulation pipe by sliding up and down, the fixed block and the piston are both provided with water holes, and a check valve is installed at the water hole; The transmission rod rotates and penetrates the fixed block, and the portion of the transmission rod located on the upper side of the fixed block is provided with a bidirectional thread, and the piston thread is sleeved on the transmission rod; A guide rod which slides through the fixed block and the piston is fixed on the upper end of the third water storage tank.

[0014] As another improved supplement of the present application, the transmission structure includes a transmission belt and two transmission pulleys, the two transmission pulleys are coaxially fixed to the output end of the driving motor and the bottom end of the transmission rod respectively, and the transmission belt is connected between the transmission belt and the transmission pulleys; through the action of the transmission structure, the driving motor drives the transmission rod to rotate during the process of driving the crystallizer body to rotate horizontally for defoaming crystallization, and the rotating transmission rod drives the piston to move reciprocatingly up and down, thereby pumping water in the third water tank into the first water tank, achieving the effect of automatic water return, without the need for an additional water pump, thereby reducing power loss.

[0015] As another improvement supplement to the present application, a dustproof and breathable cover is installed on the top of the circulation pipe, a dustproof plate is rotatably installed on the top of the second water tank, and the output shaft of the drive motor passes through the center of the dustproof plate, and the water outlet pipe passes through the dustproof plate. The setting of the dustproof and breathable cover and the dustproof plate can effectively prevent external dust and other debris from falling into the cooling water and affecting the refrigeration effect of the refrigerator.

[0016] The present invention provides a crystallizer for metal casting, which has the following beneficial effects: By setting the crystallizer body horizontally and using a driving motor to drive the crystallizer body to rotate horizontally, the metal liquid inside the crystallizer body is squeezed under the action of centrifugal force, thereby squeezing out the bubbles in the metal liquid, playing a good defoaming role, thereby improving the crystallization quality. In addition, after crystallization, the sealing cover is loosened to separate the sealing cover from the crystal body. At this time, the driving motor is continued to drive the crystallizer body to rotate horizontally, so that the crystal body inside the crystallizer body slides outward under the action of centrifugal force, which is convenient for smooth demoulding; and a heat sink is supported between the shell and the crystallization cylinder, which can enhance the overall strength of the shell. Two groups of inclined water holes arranged on the heat sink can make the cooling water close to the crystallization cylinder and the cooling water far from the crystallization cylinder convect and mix with each other, give full play to the cooling effect of the cooling water, and accelerate the crystallization speed; in addition, through the action of the transmission structure, the driving motor drives the transmission rod to rotate in the process of driving the crystallizer body to rotate horizontally for defoaming crystallization, and the rotating transmission rod drives the piston to move back and forth up and down, thereby pumping water in the third water storage tank into the first water storage tank, achieving the effect of automatic water return, without the need for an additional water pump, and reducing power loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the first embodiment of the present application; Figure 2 This is a schematic cross-sectional structure diagram of the first embodiment of the present application; Figure 3 This is a partial three-dimensional structural schematic diagram of the first embodiment of the present application; Figure 4 This is a schematic cross-sectional structure diagram of a crystallizer body according to the first embodiment of the present application; Figure 5 This is a schematic cross-sectional structure diagram of a circulation pipe according to the second embodiment of the present application; Figure 6 This is a schematic diagram of the three-dimensional structure of the heat dissipation plate of the first embodiment of the present application; Figure 7 This is a demonstration diagram of hot and cold convection in the first embodiment of the present application; Figure 8 This is a pumping demonstration diagram of the second implementation mode of this application.

[0018] Description of the numbers in the figure: 1. Crystallizer body; 101. Shell; 102. Crystallizer tube; 103. Water inlet pipe; 104. Injection pipe; 105. Heat sink; 106. Water hole; 107. First water conduit; 108. Second water conduit; 109. Sealing cover; 2. Base; 3. First water storage tank; 4. Support frame; 5. Second water storage tank; 6. Third water storage tank; 7. Drive motor; 8. Drive belt; 9. Drive pulley; 10. Drive rod; 11. Fixed block; 12. Piston; 13. Guide rod; 14. Check valve; 15. Dust-proof and breathable cover; 16. Circulation pipe; 17. Refrigerator; 18. Return pipe; 19. Outlet pipe; 20. Dust-proof plate. DETAILED DESCRIPTION

[0019] The following describes two implementation modes of the present application in detail with reference to the accompanying drawings.

[0020] Second implementation method: The present invention provides a crystallizer for metal casting, see Figure 1-Figure 4 , including a crystallizer body 1 and a base 2. The crystallizer body 1 includes an outer shell 101 and a crystallization cylinder 102 coaxially sleeved on the inner side of the outer shell 101. The axes of the outer shell 101 and the crystallization cylinder 102 are both horizontally arranged. An inlet pipe 103 is installed on one side of the outer shell 101, and an outlet pipe 19 is installed on the other side of the outer shell 101. An injection pipe 104 is installed on the upper end of the crystallization cylinder 102 near the inlet pipe 103.

[0021] A driving motor 7 is installed at the upper end of the base 2 close to the injection pipe 104, and the output end of the driving motor 7 is vertically fixed to the bottom end of the shell 101. The end of the crystallization tube 102 away from the injection pipe 104 is set to be open, and a sealing cover 109 is threadedly connected to the open end.

[0022] By setting the crystallizer body 1 horizontally and using the drive motor 7 to drive the crystallizer body 1 to rotate horizontally, the molten metal inside the crystallizer body 1 is squeezed under the action of centrifugal force, thereby squeezing out the bubbles in the molten metal, which has a good defoaming effect, thereby improving the crystallization quality. In addition, after crystallization, the sealing cover 109 is loosened to separate the sealing cover 109 from the crystal. At this time, the drive motor 7 is continued to be used to drive the crystallizer body 1 to rotate horizontally, so that the crystal inside the crystallizer body 1 slides outward under the action of centrifugal force, which is convenient for smooth demolding.

[0023] Among them, Figure 4 It is shown that a plurality of heat sinks 105 are fixed at equal intervals on the outer surface of the crystallization cylinder 102 along its length direction; the heat sinks 105 and the crystallization cylinder 102 are both made of copper, with good heat exchange effect, and the heat sinks 105 can increase the contact area with the cooling water, thereby further improving the cooling effect.

[0024] Among them, Figure 4As shown, the heat sink 105 is arranged in a ring shape, and the heat sink 105 is attached to the inner wall of the shell 101, and a plurality of water holes 106 are arranged on the heat sink 105; the heat sink 105 is supported between the shell 101 and the crystallization cylinder 102, which can enhance the overall strength of the shell 101.

[0025] Among them, Figure 4 and Figure 7 It is shown that a plurality of water holes 106 are arranged in two rings and are all arranged cocentrically with the heat sink 105. The plurality of water holes 106 are all arranged as inclined holes, and the plurality of water holes 106 close to the center of the circle are inclined along the water flow direction toward the side away from the center of the circle, and the plurality of water holes 106 away from the center of the circle are inclined along the water flow direction toward the side close to the center of the circle; the arrangement of the two groups of inclined water holes 106 can make the cooling water close to the crystallization cylinder 102 and the cooling water away from the crystallization cylinder 102 convect and mix with each other, give full play to the cooling effect of the cooling water, and accelerate the crystallization speed, wherein the warm current in the figure represents cooling water with relatively high temperature, and the cold current represents cooling water with relatively low temperature.

[0026] Among them, Figure 6 and Figure 7 It is shown that a plurality of first water pipes 107 and a plurality of second water pipes 108 are fixed to one side end of the heat sink 105 close to the water outlet pipe 19, the plurality of first water pipes 107 correspond one-to-one to the plurality of water holes 106 away from the center of the circle, and are coaxially arranged with the water holes 106, and the plurality of second water pipes 108 correspond one-to-one to the plurality of water holes 106 close to the center of the circle, and are coaxially arranged with the water holes 106; the first water pipes 107 and the second water pipes 108 can enhance the convection intensity of the cooling water close to the crystallization cylinder 102 and the cooling water away from the crystallization cylinder 102, and at the same time can further increase the contact area with the cooling water, thereby improving the cooling effect.

[0027] In this embodiment, the crystallizer body 1 is horizontally arranged, and the driving motor 7 is used to drive the crystallizer body 1 to rotate horizontally, so that the molten metal inside the crystallizer body 1 is squeezed under the action of centrifugal force, thereby squeezing out the bubbles in the molten metal, playing a good defoaming role, thereby improving the crystallization quality. In addition, after crystallization, the sealing cover 109 is loosened to separate the sealing cover 109 from the crystal. At this time, the driving motor 7 is continued to be used to drive the crystallizer body 1 to rotate horizontally, so that the crystal inside the crystallizer body 1 slides outward under the action of centrifugal force, which is convenient for smooth demoulding; and a heat sink 105 is supported between the outer shell 101 and the crystallization cylinder 102, which can enhance the overall strength of the outer shell 101, and the two groups of inclined water holes 106 arranged on the heat sink 105 can make the cooling water close to the crystallization cylinder 102 and the cooling water away from the crystallization cylinder 102 convect and mix with each other, give full play to the cooling effect of the cooling water, and accelerate the crystallization speed.

[0028] Second implementation method: This embodiment adds the following structure on the basis of embodiment 1, so that this application has the function of water circulation, and the specific configuration is as follows: Figure 1-3 As shown, a first water tank 3 is provided on the upper side of the crystallizer body 1, and the first water tank 3 is fixed to the base 2 through a support frame 4. A connected refrigerator 17 is installed on the first water tank 3, and the refrigerator 17 is connected to the water inlet pipe 103; a second water tank 5 is installed on the upper end of the base 2 close to the driving motor 7, and the side end of the second water tank 5 is fixedly connected to the third water tank 6, and the side of the third water tank 6 away from the second water tank 5 is fixedly connected to a circulation pipe 16, and a return pipe 18 is connected between the circulation pipe 16 and the first water tank 3; the outlet pipe 19 extends to the inner side of the second water tank 5 away from the end of the outer shell 101, and a pumping assembly is installed on the inner side of the circulation pipe 16, and a transmission structure is installed between the output end of the driving motor 7 and the pumping assembly.

[0029] like Figure 5 It is shown that the pumping assembly includes a transmission rod 10, a fixed block 11 and a piston 12; the transmission rod 10 is vertically rotatably installed on the third water tank 6, and the bottom end of the transmission rod 10 is connected to the transmission structure; the fixed block 11 is fixed to the inner side of the circulation pipe 16, the piston 12 is located on the upper side of the fixed block 11, and is slidably installed on the inner side of the circulation pipe 16 up and down, and water holes are provided on the fixed block 11 and the piston 12, and a check valve 14 is installed at the water hole; the transmission rod 10 rotates through the fixed block 11, and the part of the transmission rod 10 located on the upper side of the fixed block 11 is provided with a two-way thread, and the piston 12 is threadedly sleeved on the transmission rod 10; a guide rod 13 that slides through the fixed block 11 and the piston 12 is fixed to the upper end of the third water tank 6.

[0030] Among them, Figure 3 As shown, the transmission structure includes a transmission belt 8 and two transmission pulleys 9, the two transmission pulleys 9 are coaxially fixed to the output end of the driving motor 7 and the bottom end of the transmission rod 10, respectively, and the transmission belt 8 is connected between the transmission belt 8 and the transmission pulleys 9; through the action of the transmission structure, the driving motor 7 drives the transmission rod 10 to rotate during the process of driving the crystallizer body 1 to rotate horizontally for defoaming crystallization, as shown in FIG. Figure 8 As shown, the rotating transmission rod 10 drives the piston 12 to move up and down, thereby pumping water in the third water tank 6 into the first water tank 3, achieving the effect of automatic water return without the need for an additional water pump, thereby reducing power loss.

[0031] A dustproof and breathable cover 15 is installed on the top of the circulation pipe 16, a dustproof plate 20 is rotatably installed on the top of the second water tank 5, and the output shaft of the drive motor 7 passes through the center of the dustproof plate 20, and the water outlet pipe 19 passes through the dustproof plate 20. The setting of the dustproof and breathable cover 15 and the dustproof plate 20 can effectively prevent external dust and other debris from falling into the cooling water and affecting the refrigeration effect of the refrigerator.

[0032] In this embodiment, through the transmission action of the transmission belt 8 and two transmission pulleys 9, the driving motor 7 drives the transmission rod 10 to rotate during the process of driving the crystallizer body 1 to rotate horizontally for defoaming crystallization. The rotating transmission rod 10 drives the piston 12 to move up and down, thereby pumping the water in the third water tank 6 into the first water tank 3, achieving the effect of automatic water return, without the need for an additional water pump, and reducing power loss; in addition, when the crystallizer body 1 is rotating, the arranged water pumping assembly can ensure that the cooling water between the outer shell 101 and the crystallization cylinder 102 can be smoothly discharged from the water outlet pipe 19.

[0033] In view of current practical needs, the above-mentioned implementation mode adopted in this application is not limited to the scope of protection. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the scope of protection of the present invention.

Claims

1. A crystallizer for metal casting, comprising a crystallizer body (1) and a base (2), characterized in that: The crystallizer body (1) comprises an outer shell (101), and a crystallization cylinder (102) coaxially sleeved on the inner side of the outer shell (101); the axes of the outer shell (101) and the crystallization cylinder (102) are both arranged horizontally; a water inlet pipe (103) is installed on one side of the outer shell (101), and a water outlet pipe (19) is installed on the other side of the outer shell (101); an injection pipe (104) is installed on the upper end of the side of the crystallization cylinder (102) close to the water inlet pipe (103); a drive motor (7) is installed on the upper end of the side of the base (2) close to the injection pipe (104), and the output end of the drive motor (7) is vertically fixed to the bottom end of the outer shell (101); the end of the crystallization cylinder (102) away from the injection pipe (104) is arranged to be open, and a sealing cover (109) is threadedly connected to the open end.

2. A metal casting crystallizer according to claim 1, characterized in that: A plurality of heat dissipation plates (105) are fixed at equal intervals on the outer surface of the crystallization cylinder (102) along its length direction.

3. A metal casting crystallizer according to claim 2, characterized in that: The heat dissipation plate (105) is arranged in a ring shape, and the heat dissipation plate (105) is attached to the inner wall of the outer shell (101), and a plurality of water holes (106) are arranged on the heat dissipation plate (105).

4. A metal casting crystallizer according to claim 3, characterized in that: The plurality of water holes (106) are arranged in two ring shapes and are all arranged cocentrically with the heat dissipation plate (105); The plurality of water holes (106) are all arranged as inclined holes, and the plurality of water holes (106) close to the center of the circle are inclined along the direction of water flow toward a side away from the center of the circle, and the plurality of water holes (106) away from the center of the circle are inclined along the direction of water flow toward a side close to the center of the circle.

5. A metal casting crystallizer according to claim 4, characterized in that: A plurality of first water conduits (107) and a plurality of second water conduits (108) are fixed to one side end of the heat dissipation plate (105) close to the water outlet pipe (19); The plurality of first water guide pipes (107) correspond one-to-one to the plurality of water holes (106) away from the center of the circle, and are arranged coaxially with the water holes (106); The plurality of second water guide pipes (108) correspond one-to-one to the plurality of water holes (106) close to the center of the circle, and are arranged coaxially with the water holes (106).

6. A metal casting crystallizer according to claim 1, characterized in that: A first water storage tank (3) is provided on the upper side of the crystallizer body (1), the first water storage tank (3) being fixed to the base (2) via a support frame (4), a refrigerator (17) being installed on the first water storage tank (3), and the refrigerator (17) being connected to the water inlet pipe (103); A second water tank (5) is mounted on the upper end of the base (2) on a side close to the drive motor (7); a third water tank (6) is fixedly connected to the side end of the second water tank (5); a circulation pipe (16) is fixedly connected to the side of the third water tank (6) away from the second water tank (5); a return pipe (18) is connected between the circulation pipe (16) and the first water tank (3); The end of the water outlet pipe (19) away from the outer shell (101) extends to the inner side of the second water storage tank (5), a pumping assembly is installed on the inner side of the circulation pipe (16), and a transmission structure is installed between the output end of the drive motor (7) and the pumping assembly.

7. A metal casting crystallizer according to claim 6, characterized in that: The pumping assembly comprises a transmission rod (10), a fixing block (11) and a piston (12); The transmission rod (10) is vertically rotatably mounted on the third water storage tank (6), and the bottom end of the transmission rod (10) is connected to the transmission structure; The fixing block (11) is fixed to the inner side of the circulation pipe (16); the piston (12) is located on the upper side of the fixing block (11) and is slidably mounted on the inner side of the circulation pipe (16) in an up-and-down manner; the fixing block (11) and the piston (12) are both provided with water holes, and a check valve (14) is mounted at the water hole; The transmission rod (10) rotates and penetrates the fixed block (11), and a portion of the transmission rod (10) located on the upper side of the fixed block (11) is provided with a bidirectional thread, and the piston (12) is threadedly sleeved on the transmission rod (10); A guide rod (13) is fixed to the upper end of the third water storage tank (6) and slides through the fixed block (11) and the piston (12).

8. A metal casting crystallizer according to claim 7, characterized in that: The transmission structure comprises a transmission belt (8) and two transmission pulleys (9); the two transmission pulleys (9) are coaxially fixed to the output end of the drive motor (7) and the bottom end of the transmission rod (10), respectively; and the transmission belt (8) is transmission-connected between the transmission belt (8) and the transmission pulleys (9).

9. A metal casting crystallizer according to claim 7, characterized in that: A dustproof and breathable cover (15) is installed at the top end of the circulation pipe (16), a dustproof plate (20) is rotatably installed at the top end of the second water storage tank (5), an output shaft of the drive motor (7) passes through the center of the dustproof plate (20), and the water outlet pipe (19) passes through the dustproof plate (20).

Images