CN219621296U - Guide cylinder and single crystal furnace - Google Patents

Abstract

The utility model relates to a guide cylinder and a single crystal furnace, wherein the guide cylinder comprises a cylinder body and an annular supporting plate which is arranged at the upper end of the cylinder body and extends outwards in a radial direction; the annular supporting plate is provided with a sealing piece, and the sealing piece comprises a first sealing ring and a second sealing ring, wherein the first sealing ring is arranged on the upper end face of the annular supporting plate and forms sealing with the upper end face of the annular supporting plate, and the second sealing ring is arranged on the radial outer side of the first sealing ring and extends downwards to the lower side of the lower end face of the annular supporting plate. According to the scheme, through the arrangement of the sealing piece, the centering of the guide cylinder and the water cooling screen can be ensured, and the tightness between the guide cylinder and the inner cover plate of the furnace can be ensured through the first sealing ring and the second sealing ring, so that the growth environment in the furnace is stabilized, the crystallization rate of monocrystalline silicon is improved, and the productivity of the monocrystalline furnace is greatly improved.

Description

Guide cylinder and single crystal furnace

Technical Field

The utility model relates to the technical field of single crystal furnace equipment, in particular to a guide cylinder and a single crystal furnace.

Background

In the process of producing monocrystalline silicon by an RCZ (re-casting Czochralski method), the guide cylinder needs to be repeatedly lifted, wherein the guide cylinder needs to be lifted up to avoid the guide cylinder occupying the loading space when re-casting the material, and the guide cylinder needs to be lifted down to a cover plate of a thermal field to form a seal after the loading is completed, so that heat leakage is prevented. When the guide cylinder descends to the cover plate, the whole guide cylinder is supported on the cover plate.

However, the cover plate in the single crystal furnace is easy to be influenced by an in-furnace thermal field to deflect, so that after the guide cylinder is placed on the cover plate, the guide cylinder is also influenced by the cover plate to deflect, thereby causing the guide cylinder to be not centered, causing unbalanced air flow and heat in the furnace, and directly influencing the normal growth of the single crystal silicon.

Disclosure of Invention

Based on the structure, the utility model provides the guide cylinder and the single crystal furnace, so as to solve the problem that the guide cylinder is easily deflected due to the influence of deflection of the cover plate in the prior art, and the guide cylinder is not centered.

In order to achieve the above purpose, the technical scheme of the utility model is as follows:

in one aspect, the utility model provides a guide cylinder, which comprises a cylinder body and an annular supporting plate arranged at the upper end of the cylinder body and extending outwards in a radial direction;

the annular supporting plate is provided with a sealing piece, and the sealing piece comprises a first sealing ring and a second sealing ring, wherein the first sealing ring is arranged on the upper end face of the annular supporting plate and forms sealing with the upper end face of the annular supporting plate, and the second sealing ring is arranged on the radial outer side of the first sealing ring and extends downwards to the lower side of the lower end face of the annular supporting plate.

In one embodiment, an annular stress relief groove is formed at the junction of the first sealing ring and the second sealing ring.

In one embodiment, the stress relief groove is an annular groove formed in the bottom of the junction of the first seal ring and the second seal ring and opening downward.

In one embodiment, the difference in height between the lower end surface of the annular support plate and the bottom surface of the second seal ring is 3-8mm.

In one embodiment, the second seal ring and the first seal ring are made of graphite felt.

In one embodiment, the inner diameter of the first seal ring is smaller than the outer diameter of the annular support plate, and the outer diameter of the first seal ring is greater than or equal to the outer diameter of the annular support plate.

In one embodiment, the second seal ring has an inner diameter that is greater than or equal to the outer diameter of the annular support plate and equal to the outer diameter of the first seal ring.

On the other hand, the utility model also provides a single crystal furnace, which comprises a lifting device, a water cooling screen connected with the lifting device and a guide cylinder hung on the water cooling screen, wherein the guide cylinder is the guide cylinder in any embodiment.

In one embodiment, the water cooling screen is provided with a hanging piece, the hanging piece comprises hanging plates respectively arranged on each cooling water pipeline of the water cooling screen, and the hanging plates are provided with clamping grooves; the guide cylinder is provided with a hanging piece, the hanging piece comprises hanging rods which are arranged on the annular supporting plate of the guide cylinder and correspond to the hanging plates one by one, the upper ends of the hanging rods are provided with limiting heads, and the hanging rods penetrate through the clamping grooves and the limiting heads are clamped above the clamping grooves.

In one embodiment, the cooling water pipeline of the water cooling screen comprises a water inlet pipeline and two water return pipelines, wherein the water inlet pipeline and the two water outlet pipelines are uniformly distributed along the circumferential direction.

The beneficial effect of this scheme: according to the scheme, the lower end of the second sealing ring is located below the lower end face of the annular supporting plate, so that when the lower end face of the second sealing ring is in contact with the cover plate, the annular supporting plate is also suspended above the cover plate, namely, the annular supporting plate of the guide cylinder is not in contact with the cover plate, the guide cylinder is separated from the support of the cover plate in the furnace, is not influenced by deflection of the cover plate any more, can be kept in centering with the single crystal furnace, and is kept in balance of air flow and heat in the furnace. Meanwhile, the sealing piece is arranged, so that on the premise of ensuring the neutrality of the guide cylinder and the single crystal furnace, the sealing property between the guide cylinder and the inner cover plate of the furnace can be ensured, the growth environment in the furnace is stabilized, the crystallization rate of single crystal silicon is improved, and the productivity of the single crystal furnace is greatly improved.

Drawings

FIG. 1 is a schematic view of a guide shell according to an embodiment of the present utility model with a seal;

FIG. 2 is a cross-sectional view of A-A of FIG. 1;

FIG. 3 is a schematic diagram of a hanging plate and a water-cooled screen according to an embodiment of the present utility model;

FIG. 4 is a schematic diagram illustrating a structure of a guide shell and a water-cooling screen according to an embodiment of the present utility model;

fig. 5 is a schematic diagram illustrating the cooperation between a hanging rod and a hanging plate according to an embodiment of the present utility model.

Reference numerals in the drawings of the specification include: 1-draft tube, 101-barrel, 1011-interior barrel, 1012-outer barrel, 102-annular support plate, 2-sealing piece, 201-first sealing ring, 202-second sealing ring, 203-stress release ditch, 3-apron, 4-peg, 5-limit head, 6-water-cooling screen, 7-link plate, 8-draw-in groove, 9-holding ring, 10-anticreep post.

Detailed Description

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present utility model by way of illustration, and only the components related to the present utility model are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.

The structures, proportions, sizes, etc. shown in the drawings attached hereto are for illustration purposes only and are not intended to limit the scope of the utility model, which is defined by the claims, but rather by the claims.

References in this specification to orientations or positional relationships as "upper", "lower", "left", "right", "intermediate", "longitudinal", "transverse", "horizontal", "inner", "outer", "radial", "circumferential", etc., are based on the orientation or positional relationships shown in the drawings, are also for convenience of description only, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore are not to be construed as limiting the utility model. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the prior art, in the lifting process of the guide cylinder, the guide cylinder is placed on the cover plate when the guide cylinder is lowered to the lowest position, and the guide cylinder is easily deflected due to the influence of deflection of the cover plate, so that the guide cylinder is not centered, and unbalanced air flow and heat in the furnace are caused. In view of the above problems, embodiments of the present utility model provide a guide cylinder, which is separated from the support of the cover plate in the furnace when the guide cylinder is lowered to the lowest position, so as to avoid the influence of the deflected cover plate on the centering of the guide cylinder.

Specifically, at least one embodiment of the present utility model provides a guide cylinder, including a cylinder body and an annular support plate disposed at an upper end of the cylinder body and extending radially outwards;

the annular supporting plate is provided with a sealing element, and the sealing element comprises a first sealing ring and a second sealing ring, wherein the first sealing ring is arranged on the upper end face of the annular supporting plate and forms sealing with the upper end face of the annular supporting plate, and the second sealing ring is arranged on the radial outer side of the first sealing ring and extends downwards to the lower side of the lower end face of the annular supporting plate.

According to the guide cylinder provided by the embodiment, when the guide cylinder is installed, the guide cylinder is driven to descend into the single crystal furnace through the water cooling screen until the lower end face of the second sealing ring is contacted with the cover plate of the single crystal furnace, so that the lower end face of the second sealing ring is sealed with the cover plate of the single crystal furnace, and because the lower end of the second sealing ring is positioned below the lower end face of the annular supporting plate, when the lower end face of the second sealing ring is contacted with the cover plate, the annular supporting plate of the guide cylinder is also suspended above the cover plate, namely, the annular supporting plate of the guide cylinder is not contacted with the cover plate, so that the supporting force born by the guide cylinder is all from the water cooling screen, the guide cylinder can be separated from the support of the cover plate and is not influenced by deflection of the cover plate. And because the upper end face of first sealing ring and annular support plate seal fit, and when the apron of second sealing ring and single crystal growing furnace contacts, the lower terminal surface of second sealing ring also forms sealedly with the upper side combination of apron, consequently, still can form enclosed construction between draft tube and the single crystal growing furnace apron, guarantees the uniformity of the interior air current of stove and better heat preservation effect.

The draft tube that this embodiment provided through the setting of sealing member, can avoid placing on the apron at the decline in-process and receive the influence and the skew of apron, can guarantee again with the airtight between the stove inner cover board to stabilize the growing environment in the stove, improve monocrystalline silicon's crystallization rate, very big improvement monocrystalline silicon's productivity.

Hereinafter, a guide cylinder provided by an embodiment of the present utility model will be described in detail with reference to the accompanying drawings.

As shown in fig. 2, the guide cylinder 1 includes a cylinder 101 and an annular support plate 102.

Wherein the cylinder 101 is used for guiding the gas around the silicon rod during the crystal pulling process. The cylinder 101 may be implemented in various forms, for example, referring to fig. 2, and in the present embodiment, the cylinder 101 has a cylindrical structure in a cylindrical shape as a whole. Of course, the cylinder 101 may be implemented in any other suitable shape or structure according to practical needs, and the present embodiment is not limited thereto. For example, the cylinder 101 may include an inner cylinder 1011 and an outer cylinder 1012, the inner cylinder 1011 is in an inverted truncated cone structure, the outer cylinder 1012 is in a cylindrical structure, and a thermal insulation material may be filled between the inner cylinder 1011 and the outer cylinder 1012 to improve the thermal insulation effect of the guide cylinder 1.

The annular supporting plate 102 is an annular structure, and is fixed to the upper end of the cylinder 101 by integral forming or welding. For example, referring to FIG. 2, the annular support plate 102 may be an annular boss structure formed by the edges of the upper ends of the inner and outer cylinders 1011, 1012 extending radially outwardly beyond the outer wall of the outer cylinder 1012.

Referring to fig. 1 and 2, in the present embodiment, a seal member 2 is provided on an annular support plate 102, and the seal member 2 includes a first seal ring 201 and a second seal ring 202, and the first seal ring 201 and the second seal ring 202 are annular plate members.

Referring to fig. 2, in the present embodiment, the inner diameter of the first seal ring 201 is smaller than the outer diameter of the annular support plate 102, so that the first seal ring 201 can be placed on the annular support plate 102, so that the whole seal member 2 can be supported on the annular support plate 102 by the first seal ring 201, and axial positioning of the seal member 2 is achieved, and more specifically, in the present embodiment, the inner diameter of the first seal ring 201 can be equal to the diameter of the upper end opening of the guide cylinder 1. The outer diameter of the first seal ring 201 may be greater than or equal to the outer diameter of the annular support plate 102, so that the outer side of the first seal ring 201 may be connected with the inner side of the second seal ring 202 in the radial direction.

Referring to fig. 2, when the first seal ring 201 is placed on the annular support plate 102, the bottom surface of the first seal ring 201 is tightly attached to the upper end surface of the annular support plate 102, and the tightly attached state forms a first sealing portion having tightness between the bottom surface of the first seal ring 201 and the upper end surface of the annular support plate 102, so that gas can be prevented from passing between the first seal ring 201 and the annular support plate 102.

Referring to fig. 2, in the present embodiment, the second seal ring 202 is provided radially outside the first seal ring 201, for example, the second seal ring 202 may be provided on the outer edge of the first seal ring 201 by an integral molding.

In this embodiment, the inner diameter of the second seal ring 202 is greater than or equal to the outer diameter of the annular support plate 102, so that the second seal ring 202 can be sleeved outside the annular support plate 102. For example, referring to FIG. 2, in this embodiment, the inner diameter of the second seal ring 202 is slightly larger than the outer diameter of the annular support plate 102. In this way, when the second seal ring 202 is sleeved outside the annular support plate 102, a movable gap is still left between the second seal ring 202 and the annular support plate 102, that is, the second seal ring 202 has a certain movable range outside the annular support plate 102. Based on this, even when the second seal ring 202 is mounted on the inclined cover plate 3 and slightly inclined, the second seal ring 202 can be adjusted in position in the clearance in a small range, and the influence of the inclination of the second seal ring 202 on the annular support plate 102 is avoided, so that the neutrality of the guide cylinder 1 and the water cooling screen 6 can be ensured. Based on this, in an embodiment, the outer diameter of the first seal ring 201 may be slightly larger than the outer diameter of the annular support plate 102 so as to be connected to each other with the second seal ring 202 in the radial direction. The outer diameter of the first seal ring 201 is equal to the inner diameter of the second seal ring 202 so that the two can be connected to each other.

Referring to fig. 2, in the present embodiment, the lower end of the second seal ring 202 extends downward below the lower end surface of the annular support plate 102, i.e., the height of the lower end of the second seal ring 202 is lower than the height of the lower end of the annular support plate 102. In this way, in the process that the guide cylinder 1 descends along with the water cooling screen 6 in the single crystal furnace, the lower end of the second sealing ring 202 is firstly contacted with the inner cover plate 3, after the second sealing ring 202 is contacted with the cover plate 3 to form a seal, the guide cylinder 1 stops descending, at the moment, the annular supporting plate 102 is suspended above the cover plate 3, namely, the annular supporting plate 102 does not form contact with the cover plate 3, the supporting force born by the guide cylinder 1 comes from the water cooling screen 6, and the guide cylinder 1 is wholly separated from the support of the cover plate 3, so that the guide cylinder 1 is not influenced by the deflection of the cover plate 3 any more, and the centering can be kept.

Referring to fig. 2, when the lower end surface of the second seal ring 202 contacts the inner cover plate 3 of the furnace, the lower end surface of the second seal ring 202 is closely adhered to the upper surface of the cover plate 3, and a second sealing portion having sealing property is formed between the lower end surface of the second seal ring 202 and the upper surface of the cover plate 3 in the closely adhered state, so that gas can be prevented from passing between the second seal ring 202 and the cover plate 3.

Based on the above structural design, the guide cylinder 1 provided in this embodiment can ensure the centering of the guide cylinder 1 through the arrangement of the sealing member 2, and can ensure the tightness between the guide cylinder 1 and the inner cover plate 3 through the first sealing ring 201 and the second sealing ring 202, maintain a good heat preservation effect, stabilize the growth environment in the furnace, improve the crystallization rate of monocrystalline silicon, and greatly improve the productivity of the monocrystalline furnace.

In some embodiments, the distance between the lower end surface of the annular support plate 102 and the lower end surface of the second seal ring 202 is 3-8mm. Thus, when the draft tube 1 is installed in the single crystal furnace, the interval between the annular supporting plate 102 and the cover plate 3 is 3-8mm. In the actual production process, even if the cover plate 3 deflects, the upward deflection height of the cover plate 3 is not too large, so in the embodiment, the distance between the annular support plate 102 and the cover plate 3 is set to be 3-8mm, the influence on the annular support plate 102 when the cover plate 3 deflects upwards can be completely avoided, and the guide cylinder 1 and the single crystal furnace can be stably centered for a long time. Still further, the distance between the lower end surface of the annular support plate 102 and the lower end surface of the second seal ring 202 may be set to 5mm.

Referring to fig. 2, in some embodiments, an annular stress relief groove 203 is provided at the interface of the second seal ring 202 and the first seal ring 201. For example, the stress relief groove 203 may be an annular groove formed at the bottom of the junction of the first seal ring 201 and the second seal ring 202 and opening downward. The stress release groove 203 can release the stress generated by the heating of the sealing element 2 in the furnace, so that the deformation of the sealing element 2 caused by the stress can be avoided, the long-term stable maintenance of the bonding state between the second sealing ring 202 and the inner furnace cover plate 3 and the bonding state between the first sealing ring 201 and the annular supporting plate 102 can be ensured, the tightness between the guide cylinder 1 and the inner furnace cover plate 3 can be further ensured, and the growth environment in the furnace can be stabilized. In addition, the stress relief groove 203 can absorb deflection generated when the second seal ring 202 is placed on the inclined cover plate 3, does not affect the centering of the first seal ring 201 and the guide cylinder, and can ensure sealing contact of the first seal ring 201 with the annular support plate 102.

In some embodiments, the second seal ring 202 and the first seal ring 201 are made of graphite felt material, e.g., graphite hard felt. Thus, the sealing element 2 has the advantages of good rigidity, high strength, good stability and the like while having good heat preservation performance, and the sealing element 2 can be stably supported on the annular supporting plate 102 and the inner furnace cover plate 3.

On the other hand, the utility model also provides a single crystal furnace, which comprises a lifting device, a water cooling screen 6 connected with the lifting device and a guide cylinder 1 hung on the water cooling screen 6, wherein the guide cylinder 1 is the guide cylinder 1 of any embodiment.

The lifting device is in the prior art and is not used as an essential point of the utility model, so the structure of the lifting device is not repeated in the embodiment, for example, the lifting device can adopt conventional rope type lifting equipment.

Referring to fig. 2 and 3, in the present embodiment, a hanging piece is provided on the water cooling screen 6, the hanging piece includes a hanging plate 7 respectively provided on each cooling water pipe of the water cooling screen 6, and a clamping groove 8 is provided on the hanging plate 7; the guide cylinder 1 is provided with a hanging piece, the hanging piece comprises hanging rods 4 which are arranged on an annular supporting plate 102 of the guide cylinder 1 and correspond to the hanging plates 7 one by one, the upper ends of the hanging rods 4 are provided with limiting heads 5, wherein the hanging rods 4 penetrate through clamping grooves 8, and the limiting heads 5 are clamped above the clamping grooves 8.

For example, referring to fig. 4, the cooling water pipe of the water cooling screen 6 includes one water inlet pipe and two water return pipes, wherein the one water inlet pipe and the two water outlet pipes are uniformly distributed in the circumferential direction. Corresponding to the arrangement of three cooling water pipes, in this embodiment the hanging plate 7 is also provided with three and is mounted on one water inlet pipe and two water outlet pipes, respectively. Of course, in other embodiments, two cooling water pipes may be provided, namely, one water inlet pipe and one water outlet pipe, and correspondingly, the hanging plate 7 is also provided in two and is respectively installed on the water inlet pipe and the water outlet pipe.

Referring to fig. 2, corresponding to the arrangement of three hanging plates 7, in this embodiment, the hanging rods 4 on the guide cylinder 1 are also three, and the three hanging rods 4 are in one-to-one correspondence with the three hanging plates 7, and in this arrangement manner, after the guide cylinder 1 is hung on the water cooling screen 6, the gravity center of the guide cylinder is not shifted, so that a long-term stable support can be formed. Meanwhile, referring to fig. 1, corresponding to the arrangement of three hanging rods 4 on the annular supporting plate 102, in this embodiment, three through holes adapted to the hanging rods 4 are provided on the first sealing ring 201, and the diameter of the through holes is at least larger than that of the limit head 5. Thus, when installing the seal 2, three through holes on the first seal ring 201 can be aligned with three hanger rods 4, and then the seal 2 is placed on the annular support plate 102 from top to bottom.

Specifically, referring to fig. 4, in the present embodiment, the hanging plate 7 is specifically provided in a rectangular parallelepiped shape, which is fixedly mounted on the cooling water pipe by welding or bolting or the like. All be provided with draw-in groove 8 on three link plate 7, draw-in groove 8 is for setting up the breach that communicates with the external world on link plate 7, and peg 4 can follow breach horizontal direction entering draw-in groove 8 promptly. The width of draw-in groove 8 is greater than the diameter of peg 4, makes peg 4 can imbed in draw-in groove 8, simultaneously, and the width of draw-in groove 8 still is less than the diameter of spacing head 5 for after peg 4 gets into draw-in groove 8, spacing head 5 on the peg 4 can block the border at draw-in groove 8, in order to avoid spacing head 5 to pass draw-in groove 8, makes spacing head 5 can be stably supported on link plate 7.

Referring to fig. 3, in the present embodiment, the card slots 8 on the three hanging plates 7 are provided on the same side in the circumferential direction, which is understood to mean that each hanging plate 7 has a front side located at the circumferential front end and a front side located at the circumferential rear end in the circumferential direction, and the card slots 8 on the three hanging plates 7 are provided on the front side or the rear side in the circumferential direction. So, referring to fig. 4, during installation, the guide cylinder 1 rotates along the circumferential direction, and three hanging rods 4 can be simultaneously embedded into three clamping grooves 8, so that the installation is quick and convenient.

In this embodiment, the hanging plate 7 is further provided with a positioning ring 9, and the positioning ring 9 is located above the clamping groove 8, that is, the positioning ring 9 is located at the edge of the clamping groove 8 and protrudes upward from the hanging plate 7. The positioning ring 9 is provided with a notch corresponding to the notch of the clamping groove 8 so as to allow the hanging rod 4 to pass through.

Specifically, the inner diameter of the positioning ring 9 is larger than the diameter of the hanging rod 4 and smaller than the diameter of the limiting head 5, so that the hanging rod 4 can be embedded into the positioning ring 9, and the limiting head 5 cannot penetrate through the positioning ring 9, so that the hanging rod 4 can be better clamped, and in the embodiment, the inner diameter of the positioning ring 9 is slightly larger than the outer diameter of the hanging rod 4. The width of the notch on the positioning ring 9 is larger than the diameter of the hanging rod 4, so that the hanging rod 4 can be inserted into the positioning ring 9 through the notch. The hanging rod 4 can be radially limited through the positioning ring 9, and the phenomenon that the position of the guide cylinder 1 is deviated due to shaking of the hanging rod 4 in the clamping groove 8 is avoided.

Referring to fig. 5, in some embodiments, the positioning ring 9 is provided with an upward protruding anti-drop post 10 at both ends, and the distance between the two anti-drop posts 10 is smaller than the diameter of the spacing head 5. So, the anticreep post 10 at the both ends of holding ring 9 forms the anticreep structure in breach department, can avoid the head 5 of locating to break away from holding ring 9, and then can further improve the reliability of peg 4 radial positioning, avoids the position emergence skew of draft tube 1.

In other embodiments, after the guide shell 1 is lowered, in order to avoid contact with the cover plate 3, the guide shell 1 is completely lifted and lowered synchronously with the water-cooling screen 6, so that the guide shell 1 can be completely fixed on the water-cooling screen 6. Specifically, the positioning head 5 may be fixedly connected to the hanging plate 7 by a fixing member, for example, the positioning head 5 is locked and fixed to the hanging plate 7 by a fixing member such as a bolt after the positioning head 5 is supported on the hanging plate 7. Therefore, the relative position between the guide cylinder 1 and the water cooling screen 6 can be fixed, the guide cylinder 1 can synchronously lift with the water cooling screen 6, and deflection of the guide cylinder 1 when the limiting head 5 is separated from or contacted with the hanging plate 7 is avoided.

Based on the above embodiments, the use principle of the present utility model is as follows:

firstly, a sealing element 2 passes through three hanging rods 4 and then is placed on an annular supporting plate 102, then the three hanging rods 4 are respectively embedded into three clamping grooves 8 and are radially limited by utilizing a positioning ring 9, so that a guide cylinder 1 is integrally suspended on a water cooling screen 6, and then horizontal calibration and centering calibration are carried out on the guide cylinder 1 and the water cooling screen 6, so that the guide cylinder 1 and the water cooling screen 6 are kept in a centering state.

Then, the water cooling screen 6 and the guide cylinder 1 are driven by the lifting device to synchronously descend into the single crystal furnace, the descending distance can be set as the vertical distance between the lower end surface of the second sealing ring 202 and the upper surface of the cover plate 3 in the initial state in advance, and the distance value can be measured during installation or can be obtained according to an empirical value. When the guide cylinder 1 descends for a specified distance, the lifting device stops, and at the moment, the lower end surface of the second sealing ring 202 just contacts with the cover plate 3 of the single crystal furnace to form a sealing state.

In the embodiment, the guide cylinder 1 is separated from the support of the inner cover plate 3 of the furnace, so that the guide cylinder is not influenced by deflection of the cover plate 3, the guide cylinder can be kept in a centering state with the single crystal furnace all the time, the heat balance in the furnace is kept, the growth environment in the furnace is stabilized, the crystallization rate of single crystal silicon is improved, and the productivity of the single crystal furnace is greatly improved.

Meanwhile, the sealing piece 2 is arranged, so that on the premise of ensuring the neutrality of the guide cylinder 1 and the water cooling screen 6, the tightness between the guide cylinder 1 and the inner cover plate 3 of the furnace can be ensured, and the uniformity of the air flow in the furnace and the better heat preservation effect are ensured.

The foregoing describes in detail preferred embodiments of the present utility model. It should be understood that the technical features of the above embodiments may be combined in any manner, and all possible combinations of the technical features in the above embodiments are not described for brevity, however, they should be considered as the scope of the description of the present specification as long as there is no contradiction between the combinations of the technical features.

The foregoing examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims (10)

1. The guide cylinder is characterized in that the guide cylinder (1) comprises a cylinder body (101) and an annular supporting plate (102) which is arranged at the upper end of the cylinder body (101) and extends outwards in a radial direction;

the annular supporting plate (102) is provided with a sealing element (2), and the sealing element (2) comprises a first sealing ring (201) which is arranged on the upper end face of the annular supporting plate (102) and forms a seal with the upper end face of the annular supporting plate (102) and a second sealing ring (202) which is arranged on the radial outer side of the first sealing ring (201) and extends downwards to the lower side of the lower end face of the annular supporting plate (102).

2. A guide shell according to claim 1, wherein: an annular stress release groove (203) is formed at the joint of the first sealing ring (201) and the second sealing ring (202).

3. A guide shell according to claim 2, wherein the stress relief groove (203) is an annular groove formed at the bottom of the junction of the first seal ring (201) and the second seal ring (202) and opening downward.

4. A guide shell according to claim 1, wherein: the height difference between the lower end surface of the annular supporting plate (102) and the lower end surface of the second sealing ring (202) is 3-8mm.

5. A guide shell according to claim 1, wherein: the second sealing ring (202) and the first sealing ring (201) are made of graphite felt.

6. A guide shell according to claim 1, wherein: the inner diameter of the first sealing ring (201) is smaller than the outer diameter of the annular supporting plate (102), and the outer diameter of the first sealing ring (201) is larger than or equal to the outer diameter of the annular supporting plate (102).

7. The draft tube of claim 6 wherein: the second sealing ring (202) has an inner diameter greater than or equal to the outer diameter of the annular support plate (102) and equal to the outer diameter of the first sealing ring (201).

8. A single crystal furnace, characterized by comprising a lifting device, a water cooling screen (6) connected with the lifting device and a guide cylinder (1) hung on the water cooling screen (6), wherein the guide cylinder (1) is the guide cylinder (1) according to any one of claims 1-7.

9. The single crystal growing furnace of claim 8, wherein: the water cooling screen (6) is provided with a hanging piece, the hanging piece comprises hanging plates (7) which are respectively arranged on each cooling water pipeline of the water cooling screen (6), and clamping grooves (8) are formed in the hanging plates (7); be provided with the suspension member on draft tube (1), the suspension member including set up in on annular support plate (102) of draft tube (1) and with peg (4) of peg (7) one-to-one, peg (4) upper end is provided with limit head (5), wherein peg (4) wear to establish draw-in groove (8) and limit head (5) card is in draw-in groove (8) top.

10. The single crystal growing furnace of claim 9, wherein: the cooling water pipeline of the water cooling screen (6) comprises a water inlet pipeline and two water return pipelines, wherein the water inlet pipeline and the two water outlet pipelines are uniformly distributed along the circumferential direction.