Dynamic separator rotor sealing structure for preventing pulverized coal short circuit

Abstract

The utility model discloses a dynamic separator rotor sealing structure for preventing pulverized coal short circuit, which relates to the technical field of powder milling and grinding and comprises a reaction chamber of a dynamic separator consisting of a shell and a top cover, a transmission device is mounted at the top of the top cover, and a transmission shaft of the transmission device penetrates into the shell and is connected with a rotor; the top edge of the rotor is provided with a sealing ring protruding upwards, a sealing device is installed on the inner wall of the top cover and arranged on the outer side of the sealing ring in a surrounding mode, and an annular gap between the sealing device and the sealing ring is filled with sealing filler. According to the dynamic separator rotor sealing structure provided by the utility model, the sealing filler has elasticity, so that the sealing filler and the sealing ring of the rotor are in a fit state. The problem of pulverized coal short circuit of the dynamic separator is solved, and main performance indexes of the dynamic separator are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of milling and grinding, more particularly to a dynamic separator rotor sealing structure for preventing short circuit of pulverized coal. BACKGROUND

[0002] In recent years, the flexibility requirement of coal-fired thermal power generating units is higher and higher, that is, the speed and adjustment range of continuously improving the generating load of the unit to follow the requirement of the power grid for adjustment. The rapid and large amplitude adjustment of the generating load requires that the coal pulverizing system must be able to quickly and greatly adjust the amount and fineness of the coal powder entering the boiler. On the other hand, the quality of the coal for power generation also changes more and more frequently, and different coal qualities correspond to different coal powder fineness. When the coal quality changes, the fineness of the coal powder output by the coal mill must also change. These two reasons promote the increasingly wide application of dynamic separators in coal mills.

[0003] The most commonly used dynamic separator at present is a traditional dynamic and static combined separator, as shown in Figure 1 : composed of a shell and a top cover, a transmission device is installed on the top cover, a transmission shaft of the transmission device extends into the shell and is connected with a rotor, and the rotor is as shown in Figure 2 . The transmission device drives the rotor to rotate. A mixture of air and coal powder enters the shell from an inlet at the bottom of the shell, flows upward in an annular gap between an inner cone and the shell, passes through static blades, then passes through the rotor, and finally is discharged from a coal powder outlet pipe. When the mixture of air and coal powder passes through the rotor, the coal powder particles collide with the rotor blades, so that the large particle coal powder is separated from the mixture of air and coal powder, and the airflow continues to carry the fine coal powder through the rotor, thereby realizing separation of coarse and fine coal powder.

[0004] The process of the mixture of air and coal powder passing through the rotor is the main separation process of the dynamic separator, so this process determines the two main performance indicators of the separator, that is, the coal powder fineness and the coal powder uniformity. The coal powder fineness is usually measured by R90, that is, the coal powder is sieved by a sieve with a pore size of 90 microns, and the percentage of the coal powder that does not pass through the sieve in the total coal powder is the value of R90, and the smaller the value of R90, the finer the coal powder. Similarly, R200 is the percentage of the coal powder that does not pass through a sieve with a pore size of 200 microns in the total coal powder. The coal powder uniformity index n is an index reflecting the particle size distribution of the coal powder, For the dynamic separator, n is 1.1-1.2.

[0005] A large number of application cases find that a disadvantage of the traditional dynamic and static combined separator is that the fineness R90 of the coal powder reaches the requirement, but the coal powder uniformity index often fails to meet the requirement, and even if the rotation speed of the rotor is continuously increased, no effect is achieved, especially when R90 is less than 10. The low coal powder uniformity index indicates that the amount of coal powder with a particle size greater than 200 microns is greater than the required value, and increasing the rotation speed of the rotor has no effect on reducing the amount of coal powder greater than 200 microns, indicating that a part of the coal powder does not pass through the rotor and directly short-circuits into the coal powder outlet pipe. Figure 3 The position of the dynamic and static combination of the top cover is a welded structure without machining, so the dimensional and positional tolerances are relatively large. In order to ensure that the rotor does not rub against the top cover when rotating, the average gap at the dynamic and static combination position is usually not less than 10 mm. Calculated according to the diameter of the annular gap of 2000 mm, the flow area of the annular gap is 2000*3.14*10=62800 mm 2 , which is equivalent to the area of a circular hole with a diameter of 282 mm. It can be seen that the annular gap is the main reason for the unqualified coal powder uniformity index, and reducing the coal powder short-circuit phenomenon is a necessary measure to solve the unqualified coal powder uniformity index.

[0006] Therefore, how to solve the problem of coal powder short-circuit of the dynamic separator and improve the main performance indicators of the dynamic separator is a problem that needs to be solved by those skilled in the art. Practical new type content

[0007] Therefore, the utility model provides a dynamic separator rotor sealing structure for preventing coal powder short-circuit, aims at solving the above technical problems.

[0008] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0009] A dynamic separator rotor sealing structure for preventing coal powder short-circuit, comprising a reaction chamber of a dynamic separator composed of an outer shell and a top cover, a transmission device is installed on the top of the top cover, a transmission shaft of the transmission device penetrates into the inside of the outer shell and is connected with a rotor;

[0010] The top edge of the rotor has an upwardly protruding sealing ring, a sealing device is installed on the inner wall of the top cover, the sealing device is arranged on the outside of the sealing ring in a surrounding manner, and an annular gap between the sealing device and the sealing ring is filled with sealing filler.

[0011] Through the above design scheme, the utility model provides a kind of dynamic separator rotor sealing structure, sealing packing has elasticity, so sealing packing and the sealing ring of rotor are in the state of adhesion, solve the problem of dynamic separator coal powder short circuit, make the main performance index of dynamic separator be promoted.

[0012] Preferably, in the above-mentioned dynamic separator rotor sealing structure for preventing coal powder short circuit, the sealing ring is welded and fixed on the top edge of the rotor.

[0013] Preferably, in the above-mentioned dynamic separator rotor sealing structure for preventing coal powder short circuit, the outer cylindrical surface and the upper end surface of the sealing ring are both machined surfaces.

[0014] Preferably, in the above-mentioned dynamic separator rotor sealing structure for preventing coal powder short circuit, the outer cylindrical surface of the sealing ring is concentric with the rotation axis of the rotor, and the upper end surface of the sealing ring is perpendicular to the rotation axis of the rotor.

[0015] Preferably, in the above-mentioned dynamic separator rotor sealing structure for preventing coal powder short circuit, the sealing device further comprises a fixing ring and a sealing skeleton, the fixing ring and the sealing skeleton are connected by bolts, the fixing ring is welded and fixed with the top cover, and the sealing skeleton and the sealing ring form the annular gap for filling the sealing packing.

[0016] Preferably, in the above-mentioned dynamic separator rotor sealing structure for preventing coal powder short circuit, the bolts connecting the fixing ring and the sealing skeleton are coated with thread sealant.

[0017] Preferably, in the above-mentioned dynamic separator rotor sealing structure for preventing coal powder short circuit, the inner surface of the sealing skeleton is coated with a layer of Loctite glue, and the sealing packing is bonded with the Loctite glue layer.

[0018] Preferably, in the above-mentioned dynamic separator rotor sealing structure for preventing coal powder short circuit, the cross section of the sealing skeleton is Z-shaped, and the folding angles of the Z-shaped cross section are all right angles.

[0019] Preferably, in the above-mentioned dynamic separator rotor sealing structure for preventing coal powder short circuit, the sealing packing is an expanded polytetrafluoroethylene tape or an expanded graphite packing.

[0020] Through the above technical scheme, compared with the prior art, the utility model discloses a dynamic separator rotor sealing structure for preventing coal powder short circuit, which has the following beneficial effects:

[0021] 1. The sealing form between the rotor and the top cover is changed from gap type to contact type, which completely eliminates the occurrence of coal powder short circuit.

[0022] 2. The sealing filler with self-lubricating and compressibility is used as the sealing filler, so that the sealing effect and the normal rotation of the rotor are ensured.

[0023] 3. The specific installation position of the sealing device is allowed to be adjusted after the rotor and the transmission shaft are assembled, so that the accuracy of the installation of the sealing device is ensured.

[0024] 4. The bolt connection between the sealing skeleton and the fixed plate is used, so that the rotor and the sealing device are conveniently replaced. SHEET REFERENCE

[0025] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by the provided drawings without creative labor for the ordinary skilled in the art.

[0026] Figure 1 The drawing is a schematic diagram of a traditional dynamic and static combined separator in the prior art;

[0027] Figure 2 The drawing is a schematic diagram of a structure of a rotor in the prior art;

[0028] Figure 3 The drawing is a schematic diagram of an annular dynamic and static combined gap between the rotor and the top cover in the prior art;

[0029] Figure 4 The drawing is a partial enlarged view of a dynamic separator rotor sealing structure provided by the present application;

[0030] Figure 5 The drawing is a schematic diagram of a structure of a rotor provided by the present application;

[0031] Figure 6 The drawing is a schematic diagram of a structure of a sealing device provided by the present application;

[0032] Figure 7 The drawing is a schematic diagram of a dynamic separator rotor sealing structure provided by the present application.

[0033] Wherein:

[0034] 1 - shell; 2 - top cover; 3 - transmission device; 4 - rotor; 5 - wind and powder mixture; 6 - inner conical cylinder; 7 - inlet; 8 - static blade; 9 - coal powder outlet pipe; 10 - rotor blade; 11 - annular dynamic and static combined gap; 12 - sealing ring; 13 - sealing device; 14 - sealing filler; 15 - outer cylindrical surface; 16 - upper end surface; 17 - fixed ring; 18 - sealing skeleton; 19 - bolt. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0036] Referring to the drawings, Figure 4 The utility model discloses a prevent short circuit of coal dynamic separator rotor sealing structure, including by the shell 1 and the top cover 2 dynamic separator's reaction chamber that constitutes, the top cover 2 top is equipped with transmission device 3, and the transmission shaft of transmission device 3 is inwards into the shell 1, and is connected with rotor 4;

[0037] The top edge of rotor 4 has the sealing ring 12 that protrudes upwards, and the inner wall of top cover 2 is equipped with sealing device 13, and sealing device 13 is arranged around the outside of sealing ring 12, and the annular gap between sealing device 13 and sealing ring 12 is filled with sealing filler 14.

[0038] In order to further optimize the above technical scheme, the sealing ring 12 is welded and fixed on the top edge of the rotor 4.

[0039] Referring to the drawings, Figure 5 The outer cylindrical surface 15 and the upper end surface 16 of the sealing ring 12 are both machined surfaces. The machined surfaces can obtain good surface roughness, meeting the requirements of the contact sealing of the rotor 4 and the sealing filler 14.

[0040] In order to further optimize the above technical scheme, the outer cylindrical surface 15 of the sealing ring 12 is concentric with the rotation axis of the rotor 4, and the upper end surface 16 of the sealing ring 12 is perpendicular to the rotation axis of the rotor 4.

[0041] Referring to the drawings, Figure 6 The sealing device 13 further includes a fixing ring 17 and a sealing skeleton 18, and the fixing ring 17 and the sealing skeleton 18 are tightly connected through bolts 19. The fixing ring 17 is welded and fixed with the top cover 2, and the sealing skeleton 18 forms an annular gap with the sealing ring 12 for filling the sealing filler 14.

[0042] In order to further optimize the above technical scheme, the bolts 19 connecting the fixing ring 17 and the sealing skeleton 18 are smeared with thread sealant.

[0043] In order to further optimize the above technical scheme, the inner surface of the sealing skeleton 18 is coated with a layer of Loctite glue, and the sealing filler 14 is bonded with the Loctite glue layer.

[0044] In order to further optimize the above technical scheme, the cross section of the sealing skeleton 18 is Z-shaped, and the folding angles of the Z-shaped cross section are all right angles.

[0045] In order to further optimize the above technical solutions, the sealing packing 14 is an expanded polytetrafluoroethylene tape or an expanded graphite packing.

[0046] The embodiment provides a dynamic separator rotor sealing structure for preventing pulverized coal short circuit, and a gap between the rotor 4 and the top cover 2 is sealed into a contact seal, as shown in the figure. Figure 4 The sealing device 13 is an annular structure, and forms a contact seal with the sealing ring 12 of the rotor 4, as shown in the figure. Figure 6 The sealing packing 14 and the sealing skeleton 18 are firmly bonded by glue. The sealing packing 14 has self-lubricating and compressibility, such as expanded polytetrafluoroethylene tape, expanded graphite packing and the like.

[0047] The mounting process of the rotor 4 and the sealing device 13 of the embodiment is as follows:

[0048] 1, the sealing skeleton 18 and the fixed ring 17 are connected firmly by the bolt 19, and the bolt 19 is coated with thread sealant for anti-loosening.

[0049] 2, the sealing skeleton 18 and the fixed ring 17 are sleeved outside the sealing ring 12 of the rotor 4, the inner surface of the sealing skeleton 18 is coated with the Loctite glue, and then the sealing packing 14 is inserted into the annular gap between the sealing skeleton 18 and the sealing ring 12. Since the sealing packing 14 has elasticity, the sealing packing 14 is in a state of adhesion with the sealing ring 12 of the rotor 4, and the sealing device 13 is rotated to ensure flexible rotation.

[0050] 3, the rotor 4 is connected with the transmission shaft of the transmission device 3.

[0051] 4, the sealing device 13 is lifted upward and adhered to the top cover 2, and the fixed ring 17 is firmly welded to the top cover 2, as shown in the figure. Figure 7 .

[0052] Therefore, the embodiment solves the problem of coal powder short circuit of the dynamic separator, and the main performance indicators of the dynamic separator are improved, especially the coal powder uniformity indicator is improved more obviously, and the coal powder uniformity can still reach n=1.1 under the condition that R90 is less than 10. The utility model has important significance for improving the coal powder quality of the pulverizing system and ensuring the economic and stable operation of the generator set.

[0053] In the specification, each embodiment is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts of each embodiment can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the related parts can be referred to the method part.

[0054] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dynamic separator rotor sealing structure for preventing pulverized coal short circuit, comprising a reaction chamber of a dynamic separator composed of a shell (1) and a top cover (2), a transmission device (3) being mounted on the top of the top cover (2), a transmission shaft of the transmission device (3) penetrating into the inside of the shell (1) and being connected with a rotor (4); characterized in that: the top edge of the rotor (4) is provided with an upwardly protruding sealing ring (12), a sealing device (13) being mounted on the inner wall of the top cover (2) and being arranged around the outside of the sealing ring (12), and an annular gap between the sealing device (13) and the sealing ring (12) being filled with a sealing filler (14). The sealing ring (12) is welded and fixed on the top edge of the rotor (4).

2. A dynamic separator rotor seal structure to prevent short circuiting of pulverized coal according to claim 1, wherein The outer cylindrical surface (15) and the upper end surface (16) of the sealing ring (12) are both machined surfaces.

3. A dynamic separator rotor seal structure to prevent short circuiting of pulverized coal according to claim 2, wherein The outer cylindrical surface (15) of the sealing ring (12) is concentric with the rotation axis of the rotor (4), and the upper end surface (16) of the sealing ring (12) is perpendicular to the rotation axis of the rotor (4).

4. A dynamic separator rotor seal arrangement to prevent short circuiting of pulverized coal according to claim 3, wherein, The sealing device (13) further comprises a fixing ring (17) and a sealing skeleton (18), the fixing ring (17) and the sealing skeleton (18) being fastened and connected by bolts (19), the fixing ring (17) being welded and fixed with the top cover (2), and the sealing skeleton (18) and the sealing ring (12) forming the annular gap for filling the sealing filler (14).

5. A dynamic separator rotor seal structure that prevents short circuiting of pulverized coal according to claim 1, characterized in that, The bolts (19) connecting the fixing ring (17) and the sealing skeleton (18) are coated with thread sealant.

6. A dynamic separator rotor seal arrangement to prevent short circuiting of pulverized coal according to claim 5, wherein, The inner surface of the sealing skeleton (18) is coated with a layer of Loctite glue, and the sealing filler (14) is bonded with the layer of Loctite glue.

7. A dynamic separator rotor seal structure to prevent short circuiting of pulverized coal according to claim 5, wherein The cross section of the sealing skeleton (18) is Z-shaped, and the folding angles of the Z-shaped cross section are all right angles.

8. A dynamic separator rotor seal structure to prevent short circuiting of pulverized coal according to claim 5, wherein The sealing filler (14) is an expanded polytetrafluoroethylene tape or an expanded graphite packing.

9. A dynamic separator rotor seal structure that prevents short circuiting of pulverized coal according to claim 1, characterized in that, ​

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