Dynamic and static ring matching structure on coal mill

Abstract

The utility model relates to a dynamic and static ring matching structure on a coal mill, which comprises a dynamic ring and a static ring, and the dynamic ring consists of a plurality of dynamic ring modules which are uniformly distributed on the circumference; each moving ring module comprises a moving ring base and a plurality of moving ring nozzles; the movable ring base is of an arc-shaped bent plate structure with the inverted-L-shaped cross section, and the movable ring base is coaxially supported on a grinding tile tray of the coal mill through the upper transverse edge and fixedly connected with the grinding tile tray through a screw. The movable ring nozzles are connected with the outer side of the vertical edge of the movable ring base and are obliquely arranged in a curve shape from bottom to top, and the widths of the movable ring nozzles are gradually increased, so that a big-end-down air flow channel is formed between every two adjacent movable ring nozzles; the static ring comprises a static ring base and a plurality of static ring modules; the static ring base is fixedly welded on the inner wall of the coal mill barrel; the static ring base is arranged on the periphery of the movable ring, and an annular space with a narrow lower part and a wide upper part is formed between the static ring base and the outer side of the movable ring module; the static ring module is supported and fixed to the upper end of the static ring base through screws. The structure is convenient to overhaul and replace, and the operation efficiency of equipment is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of coal mills, in particular to a dynamic and static ring matching structure on a coal mill. Background Art

[0002] The moving ring and the stationary ring of the existing coal mill are both integrally cast, and the equipment material is 50Mn2. During the operation of the equipment, the moving ring of the coal mill rotates with the grinding disc, and the primary air passes through the side body of the coal mill and blows upward along the nozzle of the air ring. After mixing with the qualified coal powder inside the coal mill after being crushed, the qualified coal powder particles are sent to the boiler through the powder conveying pipeline for combustion. In this process, due to the large gap between the moving ring and the stationary ring and the unreasonable structural design, the primary air flows vertically upward between the moving ring and the stationary ring, forming a large-particle coal boiling zone above the air ring, which cannot sweep the area above the middle of the grinding disc, forming an inert area in this area, making the qualified coal in this area The coal powder is not taken away in time, and falls back to the grinding bowl to be repeatedly ground, causing the output of the coal mill to decrease, the power consumption to increase, and the wear of the grinding rollers and grinding shoes to increase. In addition, the original air ring has been in operation for a long time, and due to wear, the dynamic and static rings have a large dynamic and static gap. As the equipment is running, the air ring gap continues to wear and increase, reaching more than 20mm, which reduces the primary wind speed, thereby reducing the operating efficiency of the coal mill and increasing the pebble coal emission rate. The large amount of pebble coal emission increases the labor intensity of the workers, pollutes the surrounding environment, affects the health of the operators, and increases the coal consumption of the unit. In addition, the dynamic and static rings of the coal mill adopt an integral casting structure, which is not easy to repair and replace, and the maintenance and replacement cost is high. In addition, the dynamic and static gap of the radial structure is prone to wear. The dynamic and static gap part is easy to wear. The increasing dynamic and static gap reduces the nozzle outlet wind speed and increases the pebble coal discharge of the coal mill. Utility Model Content

[0003] Aiming at the deficiencies of the prior art, the utility model proposes a dynamic and static ring matching structure on a coal mill which is convenient for maintenance and replacement, reduces the vertical upward flow of wind, and thus can improve the operating efficiency of the equipment.

[0004] The above-mentioned purpose of the utility model is achieved through the following technical solutions:

[0005] A dynamic and static ring matching structure on a coal mill, comprising a dynamic ring and a static ring;

[0006] The moving ring is a split combined structure, which is composed of a plurality of moving ring modules with the same structure evenly distributed along the circumferential direction; the moving ring module adopts an integral casting structure; each moving ring module includes a moving ring base and a plurality of moving ring nozzles evenly distributed along the circumferential direction; the moving ring base part adopts an arc-shaped bent plate structure with an inverted L-shaped cross-section, which is coaxially supported on the grinding shoe tray of the coal mill through the upper horizontal side, and is fixedly connected to the grinding shoe tray by screws; the moving ring nozzle is connected to the outer side of the vertical side of the moving ring base, and is arranged in a curved inclination from bottom to top, and the width gradually increases, so that a larger lower and upper upper wind flow channel is formed between adjacent moving ring nozzles; the upper end face of the moving ring nozzle is arranged in a downward inclination from outside to inside, and the outer side face of the moving ring nozzle is arranged in an inward inclination from bottom to top;

[0007] The stationary ring adopts a combined structure, including a stationary ring base and multiple stationary ring modules with the same structure. The stationary ring base is an annular base, which is welded and fixed to the inner wall of the cylinder of the coal mill; the stationary ring base is arranged on the periphery of the moving ring, and an annular space with a narrow bottom and a wide top is formed between the inner side of the stationary ring base and the outer side of the moving ring module of the moving ring; the stationary ring module adopts an arc-shaped module, and the stationary ring module is supported on the upper end of the stationary ring base and fixedly connected to the stationary ring base by screws; the upper end face of the stationary ring module adopts an inclined surface shape with a high outer side and a low inner side, and the lower end of the inclined surface extends to a position close to the bottom surface of the stationary ring module.

[0008] Moreover, at least one layer of wind shield assembly is arranged between the outer side of the dynamic ring and the inner side of the static ring base, and each layer of the wind shield assembly is composed of an upper wind shield plate and a lower wind shield plate. The upper wind shield plate is fixed to the inner side of the dynamic ring nozzle in a manner of extending outward, and the lower wind shield plate is fixed to the inner side of the static ring base in a manner of extending inward, and the upper and lower wind shield plates are matched with upper and lower gaps.

[0009] Moreover, a protrusion is arranged at the lower end of the upper wind shield plate, and a corresponding groove is arranged at the upper end of the lower wind shield plate, and the protrusion extends into the groove in a clearance fit manner.

[0010] The advantages and positive effects of the utility model are:

[0011] 1. The dynamic ring and the static ring of the utility model both adopt a split combined structure and a casting structure made of wear-resistant materials. They can be partially disassembled and replaced according to the grinding and wear conditions of the equipment, which facilitates replacement and reduces the cost of later equipment maintenance.

[0012] 2. The utility model optimizes the outer side surface of the dynamic ring nozzle and the upward direction and corresponding width of the dynamic ring nozzle, realizes the guiding and accelerating functions of the primary air, and improves the working efficiency of the coal mill.

[0013] 3. The annular space with a smaller bottom and a larger top formed between the dynamic and static rings of the utility model can reduce the vertical upward flow of the primary air. Furthermore, a wind shielding component is arranged in the annular space, which can further reduce the vertical upward flow of the primary air, thereby achieving a better wind shielding effect and being beneficial to improving the operating efficiency of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the partial matching structure of the utility model;

[0015] Figure 2 yes Figure 1 The schematic diagram of the structure in which a windshield assembly is added between the moving and static rings. DETAILED DESCRIPTION

[0016] The structure of the utility model is further described below with reference to the accompanying drawings and through embodiments. It should be noted that the embodiments are descriptive rather than restrictive.

[0017] A dynamic and static ring matching structure on a coal mill, see Figure 1-Figure 2 , including dynamic ring and static ring.

[0018] The dynamic ring is designed as a split combined structure, which is composed of a plurality of dynamic ring modules with the same structure evenly distributed along the circumferential direction. The dynamic ring module adopts an integrated casting molding structure, and the material adopts a highly wear-resistant material, such as cast steel-high chromium bimetallic material. After the dynamic ring module is cast, it is formed by CNC machining, which can be mutually replaced, and can be partially replaced according to the wear condition in the later stage. Each dynamic ring module includes a dynamic ring base part 2 and a plurality of dynamic ring nozzle parts 3 evenly distributed along the circumferential direction. The dynamic ring base part adopts an arc-shaped curved plate structure with an inverted L-shaped cross section, and a screw through hole is provided on the upper horizontal side. By installing the screws, the dynamic ring base is coaxially fixed on the grinding shoe tray 1 of the coal mill. The dynamic ring nozzle is connected to the outer side of the vertical side of the dynamic ring base, and is arranged in a curved inclination from bottom to top, and the width gradually increases, so that a wind flow channel with a large bottom and a large bottom is formed between adjacent dynamic ring nozzles, which has the function of guiding and accelerating the primary air, improving the pressure difference between the inlet and outlet of the coal mill, reducing the resistance of the coal mill nozzle, improving the air-powder ratio, reducing the power consumption of the coal mill, and improving the working efficiency of the coal mill. The upper end surface 3.1 of the dynamic ring nozzle is tilted downward from outside to inside, with an inclination angle of 20-30°. This design creates a "still moment" at the nozzle outlet, improving the efficiency of separating pyrite and stone from the fuel entering the coal mill. The outer side surface 3.2 of the dynamic ring nozzle is tilted inward from bottom to top.

[0019] The stationary ring adopts a combined structure, including a stationary ring base 5 and a plurality of stationary ring modules 4 with the same structure. The stationary ring base is an annular base, which is welded and fixed on the inner wall of the cylinder of the coal mill to support the stationary ring module. A circle of threaded holes is evenly distributed along the circumferential direction at the upper end of the stationary ring base to achieve the fixed installation of the stationary ring module. The stationary ring base is arranged on the periphery of the moving ring, and an annular space with a narrow bottom and a wide top is formed between the inner side of the stationary ring base and the outer side of the moving ring module of the moving ring. The stationary ring module adopts an arc module, and a screw through hole is arranged on the stationary ring module. The stationary ring module is made of high wear-resistant material, cast steel-high chromium bimetallic material, and the stationary ring module can be mutually replaced, and can be partially replaced according to the wear condition at a later stage. The stationary ring module is supported on the upper end of the stationary ring base and is fixedly connected to the stationary ring base by installing screws. The upper end surface of the stationary ring module adopts an inclined surface shape with a high outer surface and a low inner surface, and the lower end of the inclined surface extends to a position close to the bottom surface of the stationary ring module. The large inclined surface setting can avoid coal powder accumulation and cause coal powder ignition, thereby reducing the discharge of stone coal.

[0020] An annular space with a narrow bottom and a wide top is formed between the inner side of the static ring base and the outer side of the dynamic ring module of the dynamic ring, which can reduce the vertical upward flow of primary air between the dynamic and static rings. In order to further reduce the vertical upward flow of primary air, the ideal state is: the smaller the matching gap between the dynamic ring and the static ring, the better. In the present invention, under the condition of ensuring the normal operation of the moving ring, at least one layer of windshield assembly is arranged between the outer side of the moving ring and the inner side of the stationary ring base, and each layer of windshield assembly is composed of an upper windshield plate 6 and a lower windshield plate 7. The upper windshield plate is fixed to the inner side of the moving ring nozzle in a way of extending outward (it can be formed integrally with the moving ring module, or it can be connected by welding), and the lower windshield plate is fixed to the inner side of the stationary ring base in a way of extending inward (it can be formed integrally with the stationary ring base, or it can be connected by welding). The upper and lower windshield plates are matched with upper and lower gaps, that is, the outer end plate of the upper windshield is placed above the inner end plate of the lower windshield, and a gap is left between the lower end of the upper windshield and the upper end of the lower baffle plate. Further, a protrusion 6.1 can be arranged at the lower end of the upper windshield plate, and a corresponding groove 7.1 can be arranged at the upper end of the lower baffle plate. The protrusion extends into the groove in a way of gap matching, which can further improve the wind blocking effect.

[0021] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A dynamic and static ring matching structure on a coal mill, comprising a dynamic ring and a static ring, characterized in that: The moving ring is a split combined structure, which is composed of a plurality of moving ring modules with the same structure evenly distributed along the circumferential direction; the moving ring module adopts an integral casting structure; each moving ring module includes a moving ring base and a plurality of moving ring nozzles evenly distributed along the circumferential direction; the moving ring base part adopts an arc-shaped bent plate structure with an inverted L-shaped cross-section, which is coaxially supported on the grinding shoe tray of the coal mill through the upper horizontal side, and is fixedly connected to the grinding shoe tray by screws; the moving ring nozzle is connected to the outer side of the vertical side of the moving ring base, and is arranged in a curved inclination from bottom to top, and the width gradually increases, so that a larger lower and upper upper wind flow channel is formed between adjacent moving ring nozzles; the upper end face of the moving ring nozzle is arranged in a downward inclination from outside to inside, and the outer side face of the moving ring nozzle is arranged in an inward inclination from bottom to top; The stationary ring adopts a combined structure, including a stationary ring base and multiple stationary ring modules with the same structure. The stationary ring base is an annular base, which is welded and fixed to the inner wall of the cylinder of the coal mill; the stationary ring base is arranged on the periphery of the moving ring, and an annular space with a narrow bottom and a wide top is formed between the inner side of the stationary ring base and the outer side of the moving ring module of the moving ring; the stationary ring module adopts an arc-shaped module, and the stationary ring module is supported on the upper end of the stationary ring base and fixedly connected to the stationary ring base by screws; the upper end face of the stationary ring module adopts an inclined surface shape with a high outer side and a low inner side, and the lower end of the inclined surface extends to a position close to the bottom surface of the stationary ring module.

2. The dynamic and static ring matching structure of the coal mill according to claim 1 is characterized in that: At least one layer of wind shield assembly is arranged between the outer side of the dynamic ring and the inner side of the static ring base, and each layer of the wind shield assembly is composed of an upper wind shield plate and a lower wind shield plate. The upper wind shield plate is fixed to the inner side of the dynamic ring nozzle in a manner of extending outward, and the lower wind shield plate is fixed to the inner side of the static ring base in a manner of extending inward, and the upper and lower wind shield plates are matched with each other with upper and lower gaps.

3. The dynamic and static ring matching structure of the coal mill according to claim 1 is characterized in that: A protrusion is arranged at the lower end of the upper wind shield plate, and a corresponding groove is arranged at the upper end of the lower wind shield plate, and the protrusion extends into the groove in a clearance fit manner.

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