Air ring and coal mill
By designing a wind ring device including a dynamic air ring and a static air ring in a medium-speed coal mill, the blow damage problem caused by the impact of coal powder on the cylinder wall is solved, and the safe, efficient and stable operation of the unit is achieved, and the failure rate and wear rate are reduced.
Patent Information
- Application Number
- CN202421574550.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-04
- Publication Date
- 2025-04-25
- Estimated Expiration
- 2034-07-04
AI Technical Summary
During the use of the air ring device in the medium-speed coal mill, the coal powder impacts the cylinder wall of the coal mill, which can easily cause blow-damage of the cylinder wall, affecting the safe, efficient and stable operation of the unit, and increasing the equipment failure rate and wear rate.
An air ring is designed, including a coaxially arranged driving air ring and a static air ring. The inner ring body of the driving air ring and the baffle are arranged at a preset angle to form an air flow channel at a preset angle to the ring body, so that the primary wind is purged upward and laterally through the air flow channel.
Through the improved air ring design, blow damage to the cylinder wall is effectively reduced, safe, efficient and stable operation of the unit is ensured, and equipment failure rate and wear rate are reduced.
Smart Images
Figure CN222789422U_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present disclosure belong to the technical field of coal equipment, and specifically relate to an air ring and a coal mill. Background Art
[0002] During the operation of the medium-speed coal mill, the raw coal (or pebble coal) enters between the surfaces of the two grinding parts (grinding roller and grinding disc) from the coal drop pipe, and is squeezed and ground under the action of the pressing force to be crushed into coal powder. Due to the rotation of the grinding parts, the ground coal powder is thrown to the wind ring formed by the wind ring device (the annular air duct equipped with equal flow guide blades is usually called the wind ring). The primary air (hot air) blown from the bottom to the top inside the wall of the coal mill can pass through the wind ring at a certain speed and enter the annular drying space above it, thereby drying the coal powder and bringing it into the separator at the top of the grinding area. After separation, the coarse powder that does not meet the combustion requirements is returned to the grinding area for re-grinding; the qualified coal powder is led to the primary air duct through the separator and sent to the furnace for combustion; after the debris (stones, wood, etc.) entrained by the coal is thrown to the wind ring, because the hot air from the bottom to the top is not enough to prevent it from falling, it falls to the pebble coal box through the wind ring.
[0003] During the use of the air ring device in the currently known medium-speed coal mill, the coal powder thrown up from the air ring impacts the cylinder wall of the coal mill, which has the defect of easily blowing and damaging the cylinder wall of the coal mill. This brings many problems to the safe, efficient and stable operation of the unit, and causes high equipment failure rate and wear rate, seriously affecting the safe and economical operation of the unit.
[0004] Therefore, how to solve the above problems has become a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content
[0005] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide an air ring and a coal mill.
[0006] According to a first aspect of an embodiment of the present disclosure, there is provided a wind ring, comprising a coaxially arranged dynamic wind ring and a static wind ring; the dynamic wind ring comprises a coaxially arranged inner ring and an outer ring; the inner ring comprises a ring body and a baffle; the baffle is arranged at the outer periphery of the ring body at a preset angle to the axial direction of the ring body; wherein the ring body, the baffle and the outer ring together form an airflow channel for airflow to pass through.
[0007] Optionally, along the axial direction of the ring body, the radial dimension of the ring body gradually decreases in the ring segment from the middle of the ring body to the top of the ring body.
[0008] Optionally, along the axial direction of the ring body, the radial dimension of the ring body gradually decreases in the ring segment from the middle of the ring body to the bottom end of the ring body.
[0009] Optionally, there are multiple baffles, and the multiple baffles are arranged at equal intervals on the outer periphery of the ring body.
[0010] Optionally, the static air ring is fixed to the wall of the coal mill; the dynamic air ring is fixedly connected to the grinding disc of the coal mill; the dynamic air ring rotates together with the grinding disc relative to the static air ring; wherein the static air ring includes a coaxially arranged static ring and a cover ring.
[0011] Optionally, the cover ring has adjacent guide surfaces and deflection surfaces; the guide surfaces are used to guide the airflow flowing through the airflow channel; and the deflection surfaces are used to deflect the airflow.
[0012] Optionally, the guide surface is arranged coplanar with a wall surface of the outer ring close to the ring body.
[0013] Optionally, the stationary ring and the outer ring are arranged on the bottom end surface of the cover ring; the stationary ring, the outer ring and the cover ring jointly define an air intake gap connected to the air flow channel.
[0014] According to a second aspect of an embodiment of the present disclosure, a coal mill is provided, wherein the coal mill comprises the air ring described above.
[0015] The beneficial effects of the embodiments of the present disclosure include:
[0016] In the present disclosure, since the baffle is arranged at a preset angle to the axial direction of the ring body, an air flow channel is formed in the dynamic air ring at a preset angle to the axial direction of the ring body, so that the primary air formed is swept upward and laterally through the air flow channel, which can effectively reduce the damage to the cylinder wall, thereby ensuring safe, efficient and stable operation of the unit. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the cross-sectional structure of an air ring according to an embodiment of the present disclosure;
[0018] Figure 2 This is a schematic structural diagram of an air ring according to an embodiment of the present disclosure;
[0019] Figure 3 This is a schematic structural diagram of a dynamic air ring according to an embodiment of the present disclosure;
[0020] Figure 4 This is a schematic diagram of the structure of an inner ring according to an embodiment of the present disclosure;
[0021] Figure 5 It is a structural schematic diagram of a cover plate ring according to an embodiment of the present disclosure;
[0022] Figure 6 It is a structural schematic diagram of a static ring according to an embodiment of the present disclosure;
[0023] Figure 7 It is a partial structural schematic diagram of a coal mill according to an embodiment of the present disclosure;
[0024] Figure 8 This is a schematic diagram of the cross-sectional structure of an air ring according to another embodiment of the present disclosure. In the figure, 1, dynamic air ring; 2, static air ring; 3, air flow channel; 4, air intake gap; 11, inner ring; 12, outer ring; 111, ring body; 112, baffle; 21, static ring; 22, cover ring; 221, guide surface; 222, deflector surface. DETAILED DESCRIPTION
[0025] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0026] The following is a further detailed description of the implementation methods of the present application in conjunction with the accompanying drawings and examples. The detailed descriptions and drawings of the following examples are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments. In the description of the present application, it should be noted that, unless otherwise specified, the meaning of "multiple" is more than two; the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inside", "outside", etc. is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the error tolerance range. "Parallel" is not parallel in the strict sense, but within the error tolerance range.
[0027] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.
[0028] like Figure 1-7 As shown, a wind ring includes a coaxially arranged dynamic wind ring 1 and a static wind ring 2. The dynamic wind ring 1 includes a coaxially arranged inner ring 11 and an outer ring 12, the inner ring 11 includes a ring body 111 and a baffle 112 (also called a blade), the baffle 112 is arranged at the outer periphery of the ring body 111 at a preset angle with the axial direction of the ring body 111, wherein the ring body 111, the baffle 112 and the outer ring 12 together form an airflow channel 3 for airflow to pass through.
[0029] Specifically, the coal mill includes a medium-speed coal mill, which includes a grinding cylinder and a grinding disc arranged in the grinding cylinder. The static air ring 2 is fixed to the cylinder wall of the grinding cylinder, the dynamic air ring 1 is fixedly connected to the grinding disc of the coal mill, and the dynamic air ring 1 rotates relative to the static air ring 2 together with the grinding disc.
[0030] In the present disclosure, since the baffle 112 is arranged at a preset angle to the axial direction of the ring body 111, an air flow channel 3 is formed in the dynamic air ring 1 at a preset angle to the axial direction of the ring body 111, so that the primary air formed is swept upward and laterally through the air flow channel 3, which can effectively reduce the damage to the cylinder wall, thereby ensuring safe, efficient and stable operation of the unit.
[0031] In some embodiments, along the axial direction of the ring body 111 , the radial dimension of the ring body 111 gradually decreases in the ring segment from the middle of the ring body 111 to the top of the ring body 111 .
[0032] With this arrangement, the air outlet of the air flow channel 3 is close to the center of the ring body 111, so that the coal powder particles blown by the wind can be effectively thrown back into the grinding disc, thereby ensuring effective grinding.
[0033] In some embodiments, along the axial direction of the ring body 111 , the radial dimension of the ring body 111 gradually expands in the ring segment from the middle of the outer ring 12 to the bottom end of the outer ring 12 .
[0034] In some embodiments, along the axial direction of the ring body 111 , the radial dimension of the ring body 111 gradually decreases in the ring segment from the middle of the ring body 111 to the bottom end of the ring body 111 .
[0035] By adopting the above-mentioned arrangement, it can be ensured that the air inlet of the airflow channel 3 is larger than the air outlet of the airflow channel 3, thereby ensuring the effective air intake of the airflow channel 3, thereby ensuring the effective blowing of the coal powder particles, and controlling the wind speed at the outlet of the pulverizer air ring within a reasonable range, ensuring the airflow carrying capacity, ensuring the pulverizer output, and improving the economy of the boiler.
[0036] In some embodiments, there are multiple baffles 112 , and the multiple baffles 112 are arranged at equal intervals on the outer circumference of the ring body 111 .
[0037] In some embodiments, the static air ring 2 is fixed to the wall of the coal mill, the dynamic air ring 1 is fixedly connected to the grinding disc of the coal mill, and the dynamic air ring 1 rotates together with the grinding disc relative to the static air ring 2, wherein the static air ring 2 includes a coaxially arranged static ring 21 and a cover ring 22.
[0038] In some embodiments, the cover ring 22 has adjacent guide surfaces 221 and deflector surfaces 222 , wherein the guide surfaces 221 are used to guide the airflow flowing through the airflow channel 3 , and the deflector surfaces 222 are used to deflect the airflow.
[0039] Specifically, the deflecting surface 222 and the guiding surface 221 are arranged at a preset angle.
[0040] In the present disclosure, adding the deflector surface 222 can better protect the cylinder wall structure of the coal mill.
[0041] In some embodiments, the flow guide surface 221 is arranged coplanar with the wall surface of the outer ring 12 close to the ring body 111. With this design, the conduction effect of the airflow in the coal mill and the blowing effect of the coal powder can be ensured.
[0042] In some embodiments, the stationary ring 21 and the outer ring 12 are arranged on the bottom end surface of the cover ring 22, and the stationary ring 21, the outer ring 12 and the cover ring 22 jointly define an air intake gap 4 connected to the air flow channel 3. The air intake gap can ventilate the grinding disc, which can ensure that the wind speed at the outlet of the wind ring is controlled within a reasonable range, ensure the air flow carrying capacity, and thus ensure the output of the coal mill.
[0043] In summary, the air ring disclosed in the present invention can solve the problem of insufficient output of the coal mill. It can reduce the effective flow area compared with that before the transformation, increase the flow rate of the nozzle outlet (air flow channel outlet), enhance the primary air powder carrying capacity, improve the uniformity of coal powder, improve the grinding output of the coal mill, reduce the loading force of the coal mill, reduce the maximum ventilation resistance, reduce the unit consumption of the coal mill, and discharge stone coal, effectively prevent the wind and powder from blowing damage to the grinding roller and other parts, and realize the safe, economical and stable operation of the boiler during operation.
[0044] refer to Figure 8 In the present disclosure, the coal mill includes 42 wind rings. The angle between the baffle 112 and the horizontal direction is 49°. The baffle length is 500 mm, the spacing between two adjacent baffles is 230 mm, and the blade thickness is 55 mm.
[0045] Furthermore, the diameter of the upper port of the ring body 111 is 3800 mm, and the diameter of the lower upper port of the ring body 111 is 3960 mm, wherein the wall thickness of the upper end of the ring body 111 is 80 mm. The size of the air inlet gap 4 is 5 mm. The cross-sectional size of the air outlet of the air flow channel 3 is 175 mm.
[0046] The above design can effectively ensure that the flow velocity at the nozzle outlet (air flow channel outlet) increases, the primary air powder carrying capacity is significantly enhanced, the coal powder is uniform, the grinding output of the pulverizer is significantly improved, the pulverizer loading force is reduced, the maximum ventilation resistance is reduced, the pulverizer unit consumption is reduced, and the stone coal is discharged, which effectively prevents the wind and powder from blowing damage to the grinding roller and other parts, and realizes safe, economical and stable operation of the boiler during operation.
[0047] A first aspect of an embodiment of the present disclosure provides a coal mill, which includes the above-mentioned air ring.
[0048] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.
Claims
1. A wind ring, characterized in that: The wind ring includes a coaxially arranged dynamic wind ring and a static wind ring; the dynamic wind ring includes a coaxially arranged inner ring and an outer ring; the inner ring includes a ring body and a baffle; the baffle is arranged at the outer periphery of the ring body at a preset angle to the axial direction of the ring body; wherein the ring body, the baffle and the outer ring together form an airflow channel for airflow to pass through.
2. The air ring according to claim 1, characterized in that: Along the axial direction of the ring body, the radial size of the ring body gradually decreases in the ring segment from the middle of the ring body to the top of the ring body.
3. An air ring according to claim 1 or 2, characterized in that: Along the axial direction of the ring body, the radial dimension of the ring body gradually decreases in the ring segment from the middle of the ring body to the bottom end of the ring body.
4. An air ring according to claim 1 or 2, characterized in that: There are a plurality of baffles, and the baffles are arranged at equal intervals on the outer periphery of the annular body.
5. An air ring according to claim 1 or 2, characterized in that: The static air ring is fixed to the wall of the coal mill; the dynamic air ring is fixedly connected to the grinding disc of the coal mill; the dynamic air ring rotates together with the grinding disc relative to the static air ring; wherein the static air ring includes a static ring and a cover ring which are coaxially arranged.
6. The air ring according to claim 5, characterized in that: The cover plate ring has adjacent guide surfaces and deflection surfaces; the guide surfaces are used to guide the airflow flowing through the airflow channel; and the deflection surfaces are used to deflect the airflow.
7. The air ring according to claim 6, characterized in that: The guide surface is arranged coplanar with a wall surface of the outer ring close to the ring body.
8. The air ring according to claim 5, characterized in that: The stationary ring and the outer ring are arranged on the bottom end surface of the cover ring; the stationary ring, the outer ring and the cover ring jointly define an air intake gap connected to the air flow channel.
9. A coal mill, characterized in that: The coal mill comprises the air ring according to any one of claims 1-8.