Coal mill impeller device
By designing a coal mill impeller device including an inner ring, a top ring, an outer ring and multiple blades, the problem of the inability to accurately control the emission of gravel coal and the wear of the grinding roller shaft in the prior art is solved, and efficient separation of gravel coal and optimization of the internal flow field of the coal mill is achieved, and the stability and safety of the coal mill are improved.
Patent Information
- Application Number
- CN202421264093.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-05
- Publication Date
- 2025-04-08
- Estimated Expiration
- 2034-06-05
AI Technical Summary
The existing coal mill impeller device cannot achieve precise control of gravel coal emissions, resulting in excessive gravel coal emissions and waste of fuel. At the same time, the blowing of hot primary wind causes wear of the grinding roller shaft and other parts, affecting the stability and safety of the coal mill.
A coal grinder impeller device is designed, including an inner ring, a top ring, an outer ring and a plurality of blades. The blades are composed of horizontal plates and inclined plates, and a wear-resistant overlay layer is added to the base body. The top ring can be adjusted to control the emission of gravel coal.
The efficient separation of gravel coal is achieved, with an effective separation rate of up to 88%, and the emission rate of gravel coal is as low as 0.3‰, avoiding fuel "escape". At the same time, the internal flow field structure of the coal mill is optimized, the repeated milling rate of raw coal is reduced, and the stability, reliability, economy and safety of the coal mill is improved.
Smart Images
Figure CN222724441U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of coal mill structures, and in particular relates to an impeller device for a coal mill. Background Art
[0002] The impeller device of the coal mill (also known as the moving nozzle body, nozzle ring, etc.) is an important component inside the coal mill. During the operation of the coal mill, the hot primary air passes through the hot air duct through the gravel coal chamber and enters the coal mill through the blades of the impeller for primary separation and drying of the coal powder. The hot primary air blows away the coal powder that meets the requirements, while the difficult-to-break debris such as iron blocks, gravel coal, etc. cannot be blown away by the hot primary air, and will fall into the gravel coal chamber through the blades of the impeller device, and then be scraped into the slag box by the scraper mechanism in the gravel coal chamber for discharge. Most of the impeller devices currently in use are welded structures, and the blades are evenly arranged in the impeller nozzle area at a certain angle and spacing. The material is Q345B. Limited by the structural form and material of the impeller device, the impeller device cannot achieve accurate control of the stone coal discharge amount due to changes in coal types. With the long-term operation of the equipment, the impeller device nozzle area, especially the blades, are continuously impacted by the difficult-to-crush debris or stone coal in the coal, causing serious wear, which not only causes the stone coal discharge to exceed the standard or a part of the raw coal "escapes" through the impeller device, causing significant waste of fuel. At the same time, since the grinding roller is located above the impeller, the hot primary air derived from the impeller will also cause damage to the grinding roller shaft, grinding roller shaft and grinding roller head flange surface, grinding roller lining device and other positions of the coal mill. In addition, the continuously worn impeller device is likely to cause turbulence in the flow field inside the coal mill, resulting in uneven discharge of the air-powder mixture at the coal mill outlet and even local eccentric wear, which may affect the stability of boiler combustion and the safety of unit operation in severe cases. Utility Model Content
[0003] In view of the above-mentioned technical problems, the utility model provides a coal mill impeller device to solve the problems of internal flow field turbulence and grinding roller blow damage in the existing coal mill, and designs a coal mill impeller device, which improves the stability and reliability of the coal mill operation and the economy and safety of the unit operation.
[0004] The utility model provides a coal mill impeller device, comprising a grinding disc, a grinding roller and an air inlet impeller, wherein the air inlet impeller is arranged around the outer periphery of the grinding disc, the grinding roller is located above the grinding disc and the air inlet impeller, and the grinding roller abuts the grinding disc, the air inlet impeller comprises an inner ring, a top ring, an outer ring and a plurality of blades, the outer ring is sleeved on the outer periphery of the inner ring at intervals, a plurality of blades are arranged around the inner ring and the outer ring at intervals, the top ring is detachably arranged around the top outer periphery of the inner ring, and the top ring is located at the top of the blade, the blade comprises a horizontal plate and an inclined plate, the horizontal plate is horizontally extended, two sides of the horizontal plate are respectively fixed to the inner ring and the outer ring, one end of the inclined plate is connected to one end of the horizontal plate, the other end of the inclined plate extends obliquely downward, and the horizontal plate and the inclined plate are arranged at an obtuse angle.
[0005] Furthermore, the blade includes a substrate and a wear-resistant surfacing layer, and the wear-resistant surfacing layer is located above the substrate.
[0006] Furthermore, the coal mill impeller device also includes an extension ring, and the extension ring is connected to the inner ring.
[0007] The impeller device of the coal mill is provided with a top ring on the top periphery of the inner ring, which can adjust the discharge amount of the pebble coal, thereby efficiently separating the pebble coal, with an effective separation rate of up to 88%, and a pebble coal discharge rate as low as 0.3‰, thereby avoiding a large amount of fuel "escape" and achieving significant economic benefits; the structural design of the blades not only optimizes the internal flow field structure of the coal mill and reduces the repeated grinding rate of raw coal, but also efficiently separates raw coal and coal powder, and increases the ability of hot primary air to carry coal powder. At the same time, the structure of the blades changes the position of the air outlet of the hot primary air through the impeller device, thereby reducing the damage of the wind-powder mixture to the coal mill roller shaft, roller shaft and roller head flange surface, roller lining device and other positions, thereby greatly improving the stability and reliability of the coal mill operation and the economy and safety of the unit operation. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0009] Figure 1 It is a schematic diagram of the structure of the air inlet impeller of the coal mill impeller device;
[0010] Figure 2 This is a schematic diagram of the application structure of the coal mill impeller device;
[0011] Figure 3 for Figure 1 Schematic diagram of the cross section of AA;
[0012] Figure 4 A schematic cross-sectional view of a blade. DETAILED DESCRIPTION
[0013] The utility model discloses a coal mill impeller device, which improves the stability and reliability of coal mill operation and the economy and safety of unit operation.
[0014] The following will be combined with the drawings in the utility model to clearly and completely describe the technical solution in the utility model. Obviously, what is described is only a part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.
[0015] See also Figure 1 to Figure 4 As shown, the utility model provides a coal mill impeller device, comprising a grinding disc 1, a grinding roller 3 and an air inlet impeller 2, wherein the air inlet impeller 2 is arranged around the outer periphery of the grinding disc 1, the grinding roller 3 is located above the grinding disc 1 and the air inlet impeller 2, and the grinding roller 3 abuts against the grinding disc 1, the air inlet impeller 2 comprises an inner ring 8, a top ring 7, an outer ring 3 and a plurality of blades 4, the outer ring 3 is sleeved on the outer periphery of the inner ring 8 at intervals, a plurality of blades 4 are arranged around the inner ring 8 and the outer ring 3 at intervals, the top ring 7 is detachably arranged around the top outer periphery of the inner ring 8, and the top ring 7 is located at the top of the blade 4, the blade 4 comprises a horizontal plate 6 and an inclined plate 5, the horizontal plate 6 is horizontally extended, and both sides of the horizontal plate 6 are respectively fixed on the inner ring 8 and the outer ring 3, one end of the inclined plate 5 is connected to one end of the horizontal plate 6, and the other end of the inclined plate 5 extends obliquely downward, and the horizontal plate 6 and the inclined plate 5 are arranged at an obtuse angle.
[0016] The blade 4 includes a substrate 11 and a wear-resistant surfacing layer 10 , wherein the wear-resistant surfacing layer 10 is located above the substrate 11 .
[0017] The coal mill impeller device further includes an extension ring 9 , which is connected to the inner ring 8 .
[0018] The impeller device of the coal mill is provided with a top ring 7 on the top periphery of the inner ring 8, which can adjust the discharge amount of the pebble coal, thereby efficiently separating the pebble coal, with an effective separation rate of up to 88%, and a pebble coal discharge rate as low as 0.3‰, thereby avoiding a large amount of fuel "escape" and achieving significant economic benefits; the structural design of the blade 4 not only optimizes the internal flow field structure of the coal mill and reduces the repeated grinding rate of the raw coal, but also efficiently separates the raw coal and coal powder, and increases the coal powder carrying capacity of the hot primary air. At the same time, the structure of the blade 4 changes the position of the air outlet of the hot primary air through the impeller device, thereby reducing the damage of the wind-powder mixture to the coal mill roller shaft, the roller shaft and the roller head flange surface, the roller lining device and other positions, thereby greatly improving the stability and reliability of the coal mill operation and the economy and safety of the unit operation.
[0019] The above contents are further detailed descriptions of the present invention in combination with specific preferred implementations, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.
Claims
1. A coal mill impeller device, characterized in that: The invention comprises a grinding disc, a grinding roller and an air inlet impeller, wherein the air inlet impeller is arranged around the outer periphery of the grinding disc, the grinding roller is located above the grinding disc and the air inlet impeller, and the grinding roller abuts against the grinding disc, the air inlet impeller comprises an inner ring, a top ring, an outer ring and a plurality of blades, the outer ring is sleeved on the outer periphery of the inner ring at intervals, a plurality of blades are arranged around the inner ring and the outer ring at intervals, the top ring is detachably arranged around the top outer periphery of the inner ring, and the top ring is located at the top of the blades, the blades comprise a horizontal plate and an inclined plate, the horizontal plate is extended horizontally, two sides of the horizontal plate are respectively fixed to the inner ring and the outer ring, one end of the inclined plate is connected to one end of the horizontal plate, the other end of the inclined plate extends obliquely downward, and the horizontal plate and the inclined plate are arranged at an obtuse angle.
2. A coal mill impeller device according to claim 1, characterized in that: The blade comprises a substrate and a wear-resistant surfacing layer, wherein the wear-resistant surfacing layer is located above the substrate.
3. A coal mill impeller device according to claim 1, characterized in that: The coal mill impeller device further comprises an extension ring connected to the inner ring.