Feeder and single crystal furnace

Abstract

The utility model relates to a feeder and a single crystal furnace. The single crystal furnace comprises a feeder, the feeder comprises a feeding cylinder, a lifting rod and a protective cover, a feeding port is formed in the top of the feeding cylinder, one end of the lifting rod is inserted into the feeding cylinder through the feeding port, and the other end of the lifting rod is exposed out of the feeding cylinder; the lifting rod is provided with a first clamping position and second clamping positions located below the first clamping position at intervals in the axial direction of the lifting rod, the lifting rod is movably sleeved with the protective cover, the protective cover can be installed at the second clamping positions to seal the feeding port, and the protective cover can move to the first clamping position in the axial direction of the lifting rod and is installed at the first clamping position to open the feeding port. In the transportation process of the charging barrel, the protective cover cannot fall off due to uneven ground; when the feeder is arranged in the furnace body of the single crystal furnace, the protective cover does not need to be taken off, so that raw materials in the feeding cylinder are prevented from being polluted by metal; furthermore, the protective cover can be repeatedly used and is not easy to damage, so that the raw materials in the charging barrel can be effectively protected.

Description

Technical Field

[0001] The present application relates to the technical field of single crystal silicon production equipment, and in particular to a feeder and a single crystal furnace. Background Art

[0002] A single crystal furnace is a device that converts polycrystalline silicon raw materials into single crystal silicon rods. In the traditional single crystal silicon rod production process, polycrystalline silicon raw materials are usually loaded into a quartz crucible at one time for melting, and then the single crystal silicon rod is pulled by the Czochralski method. In this production process, the quality of the single crystal silicon rod is limited by the maximum feed amount, which is determined by the size of the quartz crucible. Therefore, the length and weight of the obtained single crystal silicon rod are very limited. In order to improve efficiency, it is necessary to increase the feed amount by secondary feeding, so that more silicon materials can be put into the quartz crucible to increase the length and weight of the crystal rod, thereby reducing the cost of crystal pulling.

[0003] The feeder is a kind of secondary feeding tool that is used more frequently, which includes a cylindrical feeding barrel for melting the polysilicon raw material. During the feeding process, in order to prevent silicon chips from rising and adhering to the inner wall of the furnace body of the single crystal furnace, so as to facilitate the crystallization of the single crystal silicon growth furnace, the prior art usually uses a cloth cover to close the feeding port of the feeding barrel to achieve the above purpose. However, during the transportation of the raw materials, the cloth cover is easily damaged, and when the feeding barrel is in the furnace body of the single crystal furnace, in order to avoid the cloth cover being damaged at high temperature, the cloth cover needs to be removed, resulting in the raw materials being directly exposed to the outside. Secondly, in order to enable the feeding barrel to move up and down to travel back and forth between the auxiliary chamber and the furnace body of the single crystal furnace, a lifting device for moving the feeding barrel up and down is installed above the feeding barrel. During the long-term up and down movement of the feeding barrel, the cloth cover may be damaged, and the lifting device may be worn, causing metal to fall directly into the raw material, thereby causing metal contamination of the raw material. At the same time, during the transportation of raw materials, the cloth cover may fall off due to uneven ground, thereby failing to effectively protect the raw materials in the feeding barrel. Utility Model Content

[0004] Based on this, it is necessary to provide a feeder and a single crystal furnace including the feeder to address the problem that the feeder of the existing single crystal furnace usually uses a cloth cover to seal the feeding port of the feeding barrel, resulting in the inability to effectively protect the raw materials in the feeding barrel.

[0005] According to one aspect of the present application, a feeder is provided, comprising:

[0006] A feeding cylinder, wherein a feeding port is provided on the top of the feeding cylinder;

[0007] A lifting rod, one end of which is inserted into the feeding barrel through the feeding port and the other end is exposed from the feeding barrel, and the lifting rod has a first clamping position and a second clamping position spaced below the first clamping position in its axial direction;

[0008] A protective cover can be movably mounted on the lifting rod, and the protective cover can be installed at the second clamping position to close the feeding port; the protective cover can also be moved along the axial direction of the lifting rod to the first clamping position and installed at the first clamping position to open the feeding port.

[0009] In one embodiment, the lifting rod includes a rod body and a first protrusion, wherein the first protrusion is arranged on the outer peripheral surface of the rod body below the first clamping position and is used for the protective cover to overlap so that the protective cover is installed at the first clamping position.

[0010] In one of the embodiments, a limiting bracket is provided on the top of the feeding barrel, and the limiting bracket has a cross beam, and the cross beam is arranged at intervals on a side of the first protrusion away from the feeding port.

[0011] In one embodiment, the outer diameter of the protective cover is larger than the inner diameter of the feeding port, so that the protective cover can overlap the feeding barrel when located at the second clamping position;

[0012] Alternatively, the outer diameter of the protective cover is equal to the inner diameter of the feeding port, and the lifting rod also includes a second protrusion, which is arranged on the outer peripheral surface of the rod body below the second clamping position and is used for the protective cover to overlap so that the protective cover can be installed in the second clamping position.

[0013] In one of the embodiments, a third protrusion is further provided on the outer circumferential surface of the rod body, and the third protrusion is arranged between the feeding port and the first protrusion at intervals in the axial direction of the lifting rod.

[0014] In one embodiment, the first protrusion and the third protrusion each have at least two, and all the first protrusions and all the third protrusions are respectively arranged at intervals along the circumference of the rod body;

[0015] In the axial direction of the lifting rod, the first protrusion and the third protrusion are aligned one by one.

[0016] In one embodiment, an angle formed between two adjacent first protrusions and an angle formed between two adjacent third protrusions in the circumferential direction of the rod body is 0° to 90° respectively.

[0017] In one embodiment, the protective cover is capable of rotating around its own central axis, and the protective cover is provided with an avoidance groove running through two opposite sides of the protective cover. When the protective cover overlaps the first protrusion, the avoidance groove and the first protrusion are offset; when the protective cover rotates around its own central axis so that the avoidance groove and the first protrusion are aligned, the protective cover is capable of moving between the first clamping position and the second clamping position along the axial direction of the lifting rod.

[0018] In one of the embodiments, a handle is provided on the side of the protective cover facing away from the feeding port.

[0019] According to another aspect of the present application, a single crystal furnace is provided, comprising the feeder described in any of the above schemes.

[0020] The above-mentioned feeder and the single crystal furnace including the feeder are provided with a protective cover, and the protective cover is movably mounted on the lifting rod, so that the protective cover can be installed in the first clamping position of the lifting rod to open the feeding port of the feeding barrel, or can be installed in the second clamping position of the lifting rod to close the feeding port, so that the protective cover of the feeding barrel containing production raw materials will not fall off due to uneven ground during transportation; and when the feeder is in the furnace body of the single crystal furnace, there is no need to remove the protective cover, thereby avoiding metal contamination of the raw materials in the feeding barrel; further, compared with the cloth cover, the protective cover can be reused many times, is easy to clean and not easy to be damaged, and can effectively protect the raw materials in the feeding barrel. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a schematic diagram of a protective cover in a feeder provided in an embodiment of the present application when the feed port is closed.

[0022] Figure 2 This is a schematic diagram of a protective cover in a feeder provided in an embodiment of the present application when the feed port is opened.

[0023] FIG. 3 is an enlarged schematic diagram of region A in FIG. 1 .

[0024] Figure 4 for Figure 2 A magnified schematic diagram of area B.

[0025] Description of reference numerals:

[0026] 10. Feeder; 100. Feeding barrel; 101. Feeding port; 102. Discharging port; 200. Lifting rod; 201. First engaging position; 202. Second engaging position; 210. Rod body; 220. First protrusion; 230. Second protrusion; 240. Third protrusion; 300. Protective cover; 301. Avoidance groove; 400. Limit bracket; 500. Handle. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0028] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0029] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0030] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0031] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0032] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0033] The present application provides a feeder and a single crystal furnace including the feeder, wherein the single crystal furnace is used to melt polycrystalline silicon raw materials and pull them into required single crystal silicon rods, and the feeder is used to perform secondary feeding during the production process to increase the length and weight of the single crystal silicon rods, thereby reducing the cost of crystal pulling.

[0034] The structure of the feeder is described below by taking the example of a feeder used in a single crystal furnace for secondary feeding to pull a single crystal silicon rod. It is understandable that in other embodiments, the feeder of the present application is not limited to being used in a single crystal furnace for secondary feeding of polysilicon raw materials, but can also be used in any scenario for secondary feeding of production raw materials, which is not limited here.

[0035] An embodiment of the present application provides a single crystal furnace (not shown in the figure), including a furnace body, a sub-chamber, a lifting device and as shown in Figures 1 and Figure 2 The feeder 10 shown has a furnace body for heating polysilicon raw materials (hereinafter referred to as raw materials) to melt the raw materials, a sub-chamber for purifying the raw materials, and a lifting device for driving the feeder 10 to rise and fall to move back and forth between the sub-chamber and the furnace body.

[0036] See Figure 1 and Figure 2 , Figure 1 and Figure 2 A schematic diagram of a feeder 10 in one embodiment is shown, as shown in FIG. Figure 2As shown, the feeder 10 of this embodiment includes a feeding barrel 100, a lifting rod 200 and a protective cover 300, wherein the feeding barrel 100 is a cylindrical barrel structure, a feeding port 101 is provided on the top, and a discharge port 102 connected to the feeding port 101 is provided on the bottom, and the raw material can be put into the feeding barrel 100 through the feeding port 101. After the feeder 10 is placed in the furnace body of the single crystal furnace to melt the raw material in the feeding barrel 100, the melted raw material can flow out from the discharge port 102; one end of the lifting rod 200 is connected to the bottom cover (not shown in the figure), and is inserted into the feeding barrel 100 through the feeding port 101, and the lifting rod 200 is connected to the bottom cover (not shown in the figure) at one end. The other end of the rod 200 is exposed to the feeding barrel 100 and is connected to the lifting device, so that the lifting rod 200 can be lifted or lowered together with the feeding barrel 100 in a controllable manner, so that the feeder 10 can move back and forth between the sub-chamber and the furnace body of the single crystal furnace; or it can rise or fall relative to the feeding barrel 100, so that the bottom cover can close or open the discharge port 102; the protective cover 300 can be movably mounted on the lifting rod 200, and is used to close the feeding port 101 or open the feeding port 101, so that the raw materials can be put into the feeding barrel 100, and the raw materials in the feeding barrel 100 are protected, thereby preventing the raw materials from being exposed to the outside and being contaminated.

[0037] Preferably, the feeding barrel 100 is made of quartz material, so that the feeding barrel 100 is not easy to react with the raw materials and graphite parts, and the quartz material has less impurities, which can greatly improve the product quality of the single crystal silicon rod. The lifting rod 200 is made of metal molybdenum, which not only has high strength, but also can withstand greater force when lifting the feeding barrel 100, and does not contain metals such as iron, which can avoid metal contamination of the raw materials.

[0038] In some embodiments, please continue to refer to FIG. 1 and Figure 2 The lifting rod 200 has a first clamping position 201 and a second clamping position 202 spaced below the first clamping position 201 in its axial direction. The protective cover 300 can be installed on the second clamping position 202 to close the feed port 101 as shown in FIG. 1 . Figure 2 As shown in FIG. 1 , the lifting rod 200 is moved to the first engaging position 201 along the axial direction and installed at the first engaging position 201 to open the feeding port 101 .

[0039] Specifically, referring to Figure 3, in one embodiment, the lifting rod 200 includes a rod body 210 and a first protrusion 220. The rod body 210 is partially inserted in the feeding barrel 100 and partially exposed from the feeding barrel 100. The first protrusion 220 is arranged on the outer peripheral surface of the portion of the rod body 210 exposed from the feeding barrel 100, and is located below the first clamping position 201, for the protective cover 300 to overlap, so that the protective cover 300 is installed in the first clamping position 201; at the same time, the outer diameter of the protective cover 300 is larger than the inner diameter of the feeding port 101, so that the protective cover 300 can overlap on the feeding barrel 100 when it is located at the second clamping position 202, so that the protective cover 300 is installed in the second clamping position 202.

[0040] Or in another embodiment, Figure 4 As shown, the outer diameter of the protective cover 300 is smaller than the inner diameter of the feeding port 101. At this time, the lifting rod 200 also includes a second protrusion 230. The second protrusion 230 is arranged on the outer peripheral surface of the rod body 210 and is located below the second clamping position 202. It is used for the protective cover 300 to overlap so that the protective cover 300 can be installed at the second clamping position 202.

[0041] Thus, through the above arrangement, the protective cover 300 can be fixed on the lifting rod 200 whether the feeding port 101 is closed or opened, thereby freeing the operator's hands and facilitating the operator to perform feeding operations.

[0042] It is understandable that the way in which the protective cover 300 is installed at the first snap-in position 201 and the second snap-in position 202 is not limited to the way described in the above embodiment. It is also possible to provide a slot at the position of the rod body 210 located at the first snap-in position 201 and the second snap-in position 202 so that the protective cover 300 can be snapped into the above-mentioned slot, which can also achieve the same technical effect. This is not limited here.

[0043] Please continue to refer to Figure 3. In order to facilitate the feeding barrel 100 and the lifting rod 200 to be lifted or lowered together without relative displacement, a limit bracket 400 is provided on the top of the feeding barrel 100. In one embodiment, the limit bracket 400 is in a "door" shape, consisting of two columns and a crossbeam, the two columns are respectively connected to the top of the feeding barrel 100, the crossbeam is spaced apart on the side of the first protrusion 220 away from the feeding port 101, and the two ends of the crossbeam are respectively connected to a column, so that the crossbeam can not only be easily connected to the lifting device to enable the feeding barrel 100 and the lifting rod 200 to be lifted or lowered together, but also can abut against the first protrusion 220 when the lifting rod 200 rises to a certain distance relative to the feeding barrel 100, thereby limiting the lifting rod 200 and preventing the lifting rod 200 from rising relative to the feeding barrel 100 without restriction.

[0044] Similarly, in order to limit the lifting rod 200 when it descends relative to the feeding barrel 100, the lifting rod 200 is prevented from descending relative to the feeding barrel 100 without restriction, such as Figure 4 As shown, the outer circumferential surface of the rod body 210 is further provided with a third protrusion 240 , and the third protrusion 240 is arranged between the feeding port 101 and the first protrusion 220 in the axial direction of the lifting rod 200 at intervals.

[0045] In this way, when the protective cover 300 is installed in the first clamping position 201, the inner edge of the protective cover 300 is located between the first protrusion 220 and the crossbeam of the limiting bracket 400, and when the protective cover 300 is installed in the second clamping position 202, the inner edge of the protective cover 300 is located between the second protrusion 230 and the third protrusion 240, and when the lifting rod 200 is lowered to a certain distance relative to the feeding barrel 100, the inner edge of the protective cover 300 can abut against the third protrusion 240, thereby limiting the lifting rod 200.

[0046] It is understandable that the number of the first protrusion 220 , the second protrusion 230 , and the third protrusion 240 is not limited, and the number of the first protrusion 220 , the second protrusion 230 , and the third protrusion 240 may be one or more. When there is one first protrusion 220, one second protrusion 230 and one third protrusion 240 respectively, the first protrusion 220, the second protrusion 230 and the third protrusion 240 are aligned one by one in the axial direction of the lifting rod 200, and extend in an arc shape along the circumference of the rod body 210 respectively, and the arc angle of the extension is less than or equal to 90°; when there are multiple first protrusions 220, the second protrusions 230 and the third protrusions 240 respectively, all the first protrusions 220, all the second protrusions 230 and all the third protrusions 240 are respectively arranged at intervals along the circumference of the rod body 210, and the angle formed between two adjacent first protrusions 220, two adjacent second protrusions 230 and two adjacent third protrusions 240 on the circumference of the rod body 210 is 0°~90°. In the embodiment shown in the figure, there are two first protrusions 220, two second protrusions 230 and two third protrusions 240 respectively, and the angles formed between the two first protrusions 220, between the two second protrusions 230 and between the two third protrusions 240 on the circumferential direction of the rod body 210 are all 90°.

[0047] It can also be understood that only the first protrusion 220 and the third protrusion 240 may be provided, in which case the first protrusion 220 corresponds to the third protrusion 240 one by one, and the above is not limited thereto.

[0048] Furthermore, as shown in FIG. 3 , in order to enable the protective cover 300 to overlap the first protrusion 220 and the second protrusion 230 respectively when in the first engaging position 201 or the second engaging position 202, and to enable the protective cover 300 to not interfere with the first protrusion 220, the second protrusion 230 and the third protrusion 240 when relatively moving along the axial direction of the rod body 210, the protective cover 300 can rotate around its own central axis, and the protective cover 300 is provided with a relative projection extending through itself. The avoidance grooves 301 on both sides are preferably arc-shaped. When the protective cover 300 overlaps the first protrusion 220, the avoidance grooves 301 are staggered with the first protrusion 220, the second protrusion 230 and the third protrusion 240; when the protective cover 300 rotates around its own central axis so that the avoidance grooves 301 are aligned with the first protrusion 220, the protective cover 300 can move between the first clamping position 201 and the second clamping position 202 along the axial direction of the lifting rod 200.

[0049] In this way, when the protective cover 300 moves along the axial direction of the lifting rod 200 to the first locking position 201 or the second locking position 202, it is only necessary to rotate the protective cover 300 around its own central axis to a position where the avoidance groove 301 and the first protrusion 220, the second protrusion 230 and the third protrusion 240 are offset. The protective cover 300 can be overlapped with the first protrusion 220 and installed at the first locking position 201, or overlapped with the second protrusion 230 and installed at the second locking position 202, thereby facilitating the operation of the operator.

[0050] In addition, in order to facilitate the operator to grasp the protective cover 300 so that the protective cover 300 can move relative to the lifting rod 200, a handle 500 is provided on the side of the protective cover 300 away from the feeding port 101. In the embodiment shown in FIG3 , there are two handles 500, which are arranged at intervals along the radial direction of the protective cover 300, so that the operator can grasp a handle 500 with his left and right hands respectively, thereby facilitating the operation of the operator. In other embodiments, the number of handles 500 is not limited, as long as it is convenient for the operator to operate.

[0051] It is worth noting that in a preferred embodiment, the materials of the protective cover 300 and the limiting bracket 400 are both polyethylene tetrafluoroethylene. This is because the polyethylene tetrafluoroethylene material has excellent heat resistance and wear resistance, which can not only prevent the substances released in the high temperature environment from affecting the ingot drawing process, further improve the crystal quality, but also ensure the reliability of the protective cover 300 when it is closed.

[0052] The working principle of the above-mentioned feeder 10 is as follows:

[0053] When secondary feeding is required, the operator opens the protective cover 300, adds raw materials into the feeding barrel 100 according to the recipe, covers the protective cover 300 after completion, and then starts the lifting device to lift the limit bracket 400 or the lifting rod 200, driving the feeder 10 into the auxiliary chamber of the single crystal furnace. After the purification procedure of the auxiliary chamber of the single crystal furnace is completed, the lifting device drives the feeder 10 to gradually descend to a certain position and stop after reaching the furnace body.

[0054] After that, the lifting device drives the lifting rod 200 to descend relative to the feeding barrel 100, the bottom cover and the feeding barrel 100 move relative to each other, and the discharge port 102 is gradually opened, and the melted single crystal silicon raw material flows out from the discharge port 102 and falls into the quartz crucible below. After all the raw materials have flowed out, the lifting device drives the lifting rod 200 to rise relative to the feeding barrel 100 in the opposite direction again, so that the lifting rod 200 and the bottom cover rise together, and the gap between the bottom cover and the discharge port 102 of the feeding barrel 100 gradually decreases until the discharge port 102 is closed. The lifting device continues to lift the lifting rod 200, and also drives the feeding barrel 100 to continue to rise together and return to the auxiliary chamber. At this point, the entire feeding process is completed.

[0055] It can be seen that the feeder 10 provided by the present application solves three problems existing in the existing feeder 10. First, it can effectively prevent the protective cover 300 from falling off due to uneven ground during the transportation of raw materials; second, the feeder 10 does not need to remove the protective cover 300 in the furnace body of the single crystal furnace, so as to prevent the raw materials in the furnace from being exposed to the external environment and contaminated; third, the material of the protective cover 300 is more durable than that of cloth, can be reused many times, is easy to clean and not easy to be damaged, and can effectively protect the raw materials in the feeding barrel 100.

[0056] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A feeder, It is characterized in that include: A feeding cylinder, wherein a feeding port is provided on the top of the feeding cylinder; A lifting rod, one end of which is inserted into the feeding barrel through the feeding port and the other end is exposed from the feeding barrel, and the lifting rod has a first clamping position and a second clamping position spaced below the first clamping position in its axial direction; A protective cover can be movably mounted on the lifting rod, and the protective cover can be installed at the second clamping position to close the feeding port; the protective cover can also be moved along the axial direction of the lifting rod to the first clamping position and installed at the first clamping position to open the feeding port.

2. The feeder according to claim 1, It is characterized in that The lifting rod includes a rod body and a first protrusion, wherein the first protrusion is arranged on the outer peripheral surface of the rod body and is located below the first clamping position, and is used for the protective cover to overlap so that the protective cover is installed at the first clamping position.

3. The feeder according to claim 2, It is characterized in that A limiting bracket is provided on the top of the feeding cylinder. The limiting bracket has a crossbeam. The crossbeam is arranged at intervals on a side of the first protrusion away from the feeding port.

4. The feeder according to claim 2, It is characterized in that The outer diameter of the protective cover is larger than the inner diameter of the feeding port, so that the protective cover can overlap the feeding barrel when located at the second clamping position; Alternatively, the outer diameter of the protective cover is equal to the inner diameter of the feeding port, and the lifting rod also includes a second protrusion, which is arranged on the outer peripheral surface of the rod body below the second clamping position and is used for the protective cover to overlap so that the protective cover can be installed in the second clamping position.

5. A feeder according to any one of claims 2 to 4, It is characterized in that The outer peripheral surface of the rod body is further provided with a third protrusion, and the third protrusion is arranged between the feeding port and the first protrusion at intervals in the axial direction of the lifting rod.

6. The feeder according to claim 5, It is characterized in that There are at least two first protrusions and at least two third protrusions respectively, and all the first protrusions and all the third protrusions are arranged at intervals along the circumference of the rod body; In the axial direction of the lifting rod, the first protrusion and the third protrusion are aligned one by one.

7. The feeder according to claim 6, It is characterized in that An angle formed between two adjacent first protrusions and between two adjacent third protrusions in the circumferential direction of the rod body is 0° to 90° respectively.

8. The feeder according to claim 2, It is characterized in that The protective cover can rotate around its own central axis, and the protective cover is provided with an avoidance groove running through the opposite sides of the protective cover. When the protective cover overlaps the first protrusion, the avoidance groove and the first protrusion are offset; when the protective cover rotates around its own central axis so that the avoidance groove and the first protrusion are aligned, the protective cover can move between the first clamping position and the second clamping position along the axial direction of the lifting rod.

9. The feeder according to claim 1, It is characterized in that A handle is provided on one side of the protective cover away from the feeding port.

10. A single crystal furnace, It is characterized in that Comprising the feeder as claimed in any one of claims 1 to 9.

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