Powder selecting and resistance reducing device of vertical mill

Abstract

The utility model relates to the technical field of vertical mills, and discloses a powder selecting and resistance reducing device of a vertical mill, which comprises a guide plate, a lower flow limiting plate, a material returning plate, a sedimentation flow limiting plate and an upper flow limiting plate, the guide plate guides gas and solid on a nozzle ring of the vertical mill to a powder returning conical hopper of a powder selecting machine of the vertical mill, and under the action of the lower flow limiting plate, the speed and the direction of airflow are ensured. And then, under the action of a powder return cone of the powder concentrator, the coarse particles settle and fall, and return to the grinding disc through a material return plate to be continuously ground. Gas and powder flow upwards in a baffling manner, and under the action of the upper flow limiting plate, the gas flow and the powder are ensured to smoothly enter the powder concentrator for powder concentration; according to the powder selecting and resistance reducing device of the vertical mill, the power consumption of the working procedure of a grinding system of the vertical mill can be reduced by more than 1.0 kWh / t, the minimum power consumption of the raw material grinding working procedure of the vertical mill can be within 11.0 kWh / t, and meanwhile, the output of the vertical mill can be improved by more than 10% under the condition that the requirement of conveying equipment is met.

Description

Technical Field

[0001] The utility model relates to the technical field of vertical mills, in particular to a vertical mill powder selection and resistance reduction device. Background Art

[0002] Vertical mill, also known as vertical mill and vertical roller mill, its grinding principle is similar to the mill used by our ancestors to grind grain. It adopts the material bed grinding principle to grind materials, overcoming many defects of the ball mill grinding mechanism. It has the advantages of high grinding efficiency, low power consumption (saving 20% ​​to 30% more electricity than ball mill), large drying capacity, large particle size of materials entering the mill, simple grinding process, small footprint, low civil engineering cost, low noise, low wear, long life, easy operation, etc. With the birth of preheating and pre-decomposition technology and the large-scale development of new dry cement production lines, vertical mills have been widely used in the cement industry, and their technical level has been further improved and improved. Various types of vertical mills have been developed one after another and have achieved success.

[0003] At present, the power consumption of vertical mills in the industry is still relatively high, and its power consumption is generally higher than that of roller press systems. In the environment of "carbon peak and carbon neutrality" and increasingly fierce market competition, it is still necessary to invest a lot of financial and human resources to carry out technical research. To carry out major technical transformation of existing vertical mills or replace them with roller presses, not only the investment cost itself is high, but also time and space are problems. Especially in recent years, the development of infrastructure has been sluggish and the cement market has reached an unprecedented low. Most people are unwilling to invest too much cost in technical transformation. Through the analysis and research of the operating conditions of vertical mills, and drawing on the working principles of primitive stone mills and modern vertical mill grinding, and the operating conditions of roller press grinding systems, combined with multiple observations and demonstrations inside the vertical mill and theoretical deductions of vertical mill grinding, it is believed that the current output and power consumption of vertical mills still have a lot of room for improvement, especially in reducing the system pressure difference of vertical mills and improving powder selection efficiency, there is great energy-saving potential. Summary of the Invention

[0004] To address the aforementioned issues with the existing technology, the present invention provides a vertical mill selection and resistance reduction device. This device addresses the energy waste and low output issues associated with vertical mills, while also reducing vibration to ensure safe operation. This device enables more stable raw material grinding, resulting in higher output and lower power consumption. Furthermore, it can be applied to cement grinding, slag grinding, metallurgical grinding, and other applications, laying a solid foundation for achieving the dual carbon goals.

[0005] To achieve the above objectives, the utility model is implemented through the following technical solutions: a vertical mill powder selection resistance reduction device, including a guide plate, a lower flow limiting plate, a return plate, a sedimentation flow limiting plate, and an upper flow plate. The guide plate is installed on the vertical mill shell, the lower flow limiting plate and the return plate form a whole, and are fixed to the return powder cone shell through a rib plate. The sedimentation flow limiting plate is directly welded to the powder return cone of the powder selector. The upper flow plate is welded to the vertical mill shell outside the powder selector at the top, and the lower end is connected to the top of the guide plate and welded.

[0006] Preferably, the guide plate can guide the gas and material coming from the nozzle ring to the top of the center of the vertical mill grinding disc, so that the coarse particles can directly fall back to the grinding disc for grinding without increasing power.

[0007] Preferably, the lower flow limiting plate can ensure that all the gas from the nozzle ring flows to the upper part of the vertical mill, and can also ensure a certain wind speed to prevent fine powder from settling back to the grinding disc.

[0008] Preferably, the return plate allows the settled coarse particles to fall in front of the roller table of the vertical mill without increasing power, thereby reducing the number of ineffective circulations of the coarse particles in the mill, thereby reducing the vertical mill pressure difference and material layer thickness, and reducing the operating load of the vertical mill main motor and circulation fan to a certain extent.

[0009] Preferably, the sedimentation flow limiting plate allows coarse particles to settle down and prevents fine powder from settling while ensuring a certain wind speed.

[0010] Preferably, the upper flow plate is used to ensure the upward air flow velocity, prevent the air flow velocity from being too low, which may cause the fine powder to settle and affect the output and power consumption of the vertical mill, and at the same time ensure a certain ventilation area to prevent the air flow velocity from being too fast and the gas flow from being too small, which may affect the normal operation of the vertical mill.

[0011] Preferably, the guide plate is made of wear-resistant material and can withstand long-term erosion and wear of materials.

[0012] Preferably, the angle between the guide plate and the vertical shell is 5° to 10°.

[0013] Preferably, the wind speed between the lower flow limiting plate and the guide plate is 15m / s to 20m / s.

[0014] Preferably, the wind speed between the upper flow plate and the powder classifier cone is 15m / s to 20m / s. Beneficial effects

[0015] The utility model provides a vertical mill powder selection and resistance reduction device. Compared with the original vertical mill, the vertical mill powder selection and resistance reduction device can reduce the power consumption of the powder grinding by more than 1.0kWh / t, and the power consumption of the raw material grinding process of the vertical mill can be as low as 11.0kWh / t. At the same time, when the system conveying equipment meets the requirements, the hourly output can be increased by more than 10%, and under the same output conditions, the operating load of the vertical mill main motor and the vertical mill circulation fan is reduced, the vertical mill grinding roller pressure can be appropriately reduced, and the operating load of the main reducer is also reduced, which effectively extends the service life of the main equipment of the vertical mill grinding system. After installing the vertical mill powder selection and resistance reduction device, the grinding power consumption is lower than that of the traditional vertical mill grinding system, and the operation is safer. Calculated based on a 1.0kWh / t reduction in raw material grinding power consumption, the country produces 1.5 billion tons of cement annually, requiring about 1.8 billion tons of raw materials to be ground, with vertical grinding systems accounting for about 60%. This means that about 1.1 billion kWh of electricity can be saved annually. In addition, it can also be applied to cement grinding, slag grinding, and metallurgy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure in the utility model.

[0017] In the figure, 1-upper flow plate, 2-guide plate, 3-lower flow plate, 4-return plate, 5-sedimentation flow plate, 6-powder return cone of powder selector, 7-vertical mill shell. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] See also Figure 1The present invention provides a technical solution: a vertical mill powder selection and resistance reduction device, comprising a guide plate, a lower flow restriction plate, a return plate, a sedimentation flow restriction plate, and an upper flow plate. The guide plate is installed on the vertical mill shell, the lower flow restriction plate and the return plate form a whole, and are fixed on the return powder cone shell by a rib plate. The sedimentation flow restriction plate is directly welded on the return powder cone of the powder classifier, and the upper flow plate is welded on the vertical mill shell outside the powder classifier, and the lower end is connected to the top of the guide plate and welded. The guide plate can guide the gas and material from the nozzle ring to the top of the vertical mill grinding disc, so that the coarse particles can directly fall back to the grinding disc for grinding without increasing the power. The lower flow restriction plate ensures that the gas from the nozzle ring all runs to the upper part of the vertical mill, and can also ensure a certain wind speed to prevent the fine powder from settling back to the grinding disc. The return plate can make the settled coarse powder Before the particles fall onto the roller table of the vertical mill, the number of ineffective circulations of coarse particles in the mill is reduced, thereby reducing the thickness of the vertical abrasive layer and the pressure difference of the vertical mill, and to a certain extent reducing the operating load of the vertical mill main motor and circulating fan. The sedimentation limiting plate allows the coarse particles to settle down and prevents the sedimentation of fine powder while ensuring a certain wind speed. The upper limit plate ensures the upward air flow speed to prevent the fine powder from settling due to too low air flow speed, which affects the output and power consumption of the vertical mill. At the same time, it ensures a certain ventilation area to prevent the air flow speed from being too fast and the gas flow from being too small, which affects the normal operation of the vertical mill. The guide plate is made of wear-resistant material and can withstand long-term erosion and wear of the material. The angle between the guide plate and the vertical shell is 5°~10°, the wind speed between the lower limit plate and the guide plate is 15m / s~20m / s, and the wind speed between the upper limit plate and the cone of the powder classifier is 15m / s~20m / s.

[0020] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations,

[0021] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A vertical grinding powder selection resistance reduction device, characterized by: It includes a guide plate, a lower flow limiting plate, a return plate, a sedimentation flow limiting plate and an upper flow plate. The guide plate is fixedly connected to the vertical mill shell. The lower flow limiting plate and the return plate form a whole and are fixedly connected to the return powder cone shell through a rib plate. The sedimentation flow limiting plate is welded to the surface of the return powder cone of the powder classifier. The top of the upper flow plate is welded to the surface of the vertical mill shell outside the powder classifier, and the lower end is fixedly connected to the top of the guide plate.

2. A vertical grinding powder separation resistance reduction device according to claim 1, characterized in that: The guide plate guides the gas and materials coming from the nozzle ring to the top of the center of the vertical mill grinding disc, and makes the coarse particles fall back into the grinding disc.

3. A vertical grinding powder separation resistance reduction device according to claim 2, characterized in that: The lower flow restriction plate ensures that all the gas coming from the nozzle ring flows toward the upper part of the vertical mill and prevents fine powder from settling back to the grinding disc.

4. A vertical grinding powder separation resistance reduction device according to claim 3, characterized in that: The return plate allows the settled coarse particles to fall to the inner side of the roller table of the vertical mill roller, and to a certain extent reduces the operating load of the vertical mill main motor and the circulating fan.

5. The vertical grinding powder separation resistance reduction device according to claim 4, characterized in that: The sedimentation limiting plate allows coarse particles to settle while preventing fine powder from settling.

6. The vertical grinding powder separation resistance reduction device according to claim 5, characterized in that: The upper flow plate ensures the upward air flow velocity to prevent the air flow velocity from being too low, which causes the fine powder to settle and affects the vertical mill output and power consumption.

7. The vertical grinding powder separation resistance reduction device according to claim 1, characterized in that: The guide plate is made of wear-resistant material.

8. The vertical grinding powder separation and resistance reduction device according to claim 1, characterized in that: The included angle between the guide plate and the vertical shell is 5° to 10°.

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