A particle size distribution adjustable powder selecting device
By designing a powder classifier with adjustable particle size distribution, the problem of high water demand in cement can be solved by adjusting the particle size distribution, thereby improving cement quality and saving resources.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 张嘉程
- Filing Date
- 2025-07-03
- Publication Date
- 2026-06-05
Smart Images
Figure CN224321850U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of cement production equipment, and more particularly to a cement classifier with adjustable particle size distribution. Background Technology
[0002] The water demand of cement is a crucial technical indicator. Generally, it is required that the water demand be less than or equal to 26%. Higher water demand means more cement needs to be added to the concrete to achieve the required grade. Cement performance and water demand are related to the cement particle size distribution. A wide particle size distribution and low uniformity coefficient result in lower water demand; conversely, a narrow particle size distribution and high uniformity coefficient result in higher water demand.
[0003] In cement production, cement grade is generally controlled by specific surface area; a certain specific surface area is sufficient to achieve the corresponding cement grade. Clinker and 3-5% gypsum are crushed by the grinding rollers of a vertical cement mill. The crushed material is then blown up by an upward swirling airflow and separated into fine powder with a specific surface area by an upper-level classifier—this is cement. The width of the cement particle size distribution depends on the content of fine powder produced by the grinding rollers before classification. Early cement produced by vertical cement mills had a high water demand, between 27-30%, failing to meet the required 26% water demand. To reduce the water demand, some methods involved increasing roller compression to increase the fine powder content, widen the cement particle size distribution, and reduce the water demand. However, increasing roller compression had limited effectiveness. To further increase the fine powder content, current technology involves adding more easily ground gypsum to the raw materials, with a maximum addition of 9% and an average of 8.5%, to reduce the water demand to 25.2-26%. Existing technologies also include directly using 4.5-6% of easily grindable limestone to increase the fine powder content and reduce the cement water demand to below 26%. This method does not use the method of simply increasing roller pressing to reduce the cement water demand. However, limestone is an inert particle in cement, has no activity, and only plays a filling role, which is a waste of resources. Some concrete mixing plants require pure silicate cement, which cannot meet market requirements.
[0004] There are three types of cement grinding: ball mills, combined mills, and vertical cement mills. Although vertical cement mills are the most energy-efficient, statistics from 2022 show that only 96 vertical cement mills were used in China, and production lines using vertical cement mills accounted for only 1.74% of the total cement production lines. Clearly, the market has not accepted vertical cement mills with uncertain performance that rely on simple pressurization to solve the water demand problem, or vertical cement mills that rely on adding limestone to solve the water demand problem.
[0005] Cement grinding involves ball mills and combined grinding systems. Ball mills and classifiers can form a closed-circuit grinding system, while a standalone ball mill is called an open-circuit grinding system. Closed-circuit grinding is 30% more energy-efficient than open-circuit grinding, but it produces products with a narrower particle size distribution and higher water demand. Currently, some manufacturers are abandoning closed-circuit grinding in favor of open-circuit grinding. However, the particle size distribution of cement vertical mills is already fixed; it's impossible to increase the fine powder content to the required level using grinding methods. Utility Model Content
[0006] The purpose of this utility model is to solve one or more of the above-mentioned technical problems. On the one hand, this utility model provides a powder sorting device with adjustable particle size distribution.
[0007] This utility model provides a particle size distribution adjustable powder classifier, including a main shell, a first powder classifier disposed inside the main shell, an auxiliary shell disposed outside the main shell, a second powder classifier disposed inside the auxiliary shell, and an external expansion channel connecting the inner cavity of the main shell and the inner cavity of the auxiliary shell; the main shell is provided with a feed inlet, the upper part of the first powder classifier is provided with a first fine material outlet, and the lower part of the first powder classifier is provided with a first coarse material outlet for discharging to the outside of the main shell; the upper part of the second powder classifier is provided with a second fine material outlet, and the lower part of the second powder classifier is provided with a second coarse material outlet for discharging to the outside of the auxiliary shell; the bottom of the main shell is provided with a first air inlet channel, and the bottom of the auxiliary shell is provided with a second air inlet channel.
[0008] This application provides a particle size distribution adjustable classifier, which has multiple auxiliary shells connected by an external expansion channel in the main shell to accommodate a second classifier with different specifications than the first classifier. By differentiating the specifications of the first and second classifiers, the particle size distribution of the first fine material outlet, the first coarse material outlet, the second fine material outlet, and the second coarse material outlet can be adjusted, which can be used to optimize and adjust the particle size distribution of the finished cement through subsequent mixing in different ways.
[0009] In some embodiments, the main housing includes a frustoconical first housing for accommodating a first classifier, a second housing in the shape of an inverted cone located below the first housing, and a third housing located above the first housing and having a first fine material outlet; an external expansion channel is installed in the first housing.
[0010] In some embodiments, the second air intake channel includes an annular air box disposed at the bottom of the auxiliary housing, an external air inlet disposed in the annular air box, and an air replenishment guide channel disposed inside the annular air box and communicating with the auxiliary housing; the number of air replenishment guide channels is multiple.
[0011] In some embodiments, multiple air supply channels are inclined to supplement the auxiliary housing with swirling airflow.
[0012] In some embodiments, there are multiple auxiliary shells, which are evenly distributed around the outer periphery of the main shell, and a corresponding number of second classifiers are installed inside the multiple auxiliary shells.
[0013] In some embodiments, the present invention also provides a movable and adjustable mounting mechanism for an embodiment in which a screw feeder is configured at the feed inlet. Attached Figure Description
[0014] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:
[0015] Figure 1 A schematic diagram of a particle size distribution adjustable powder sorting device according to one embodiment of the present invention;
[0016] Figure 2 for Figure 1 A partial schematic diagram of the annular air box of a particle size distribution adjustable powder sorting device according to one embodiment is shown.
[0017] Figure 3 for Figure 2 A cross-sectional view of a particle size distribution adjustable powder sorting device according to one embodiment is shown at point AA.
[0018] Figure 4 A diagram of an adjustable particle size distribution powder sorting system provided in this application. Detailed Implementation
[0019] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.
[0020] This utility model provides a particle size distribution adjustable powder classifier, including a main housing 1, a first powder classifier 2 disposed inside the main housing 1, an auxiliary housing 3 disposed outside the main housing 1, a second powder classifier 4 disposed inside the auxiliary housing 3, and an external expansion channel 5 connecting the inner cavity of the main housing 1 and the inner cavity of the auxiliary housing 3; the main housing 1 is provided with a feed inlet 8, the upper part of the first powder classifier 2 is provided with a first fine material outlet 21, and the lower part of the first powder classifier 2 is provided with a first coarse material outlet 22 for discharging material out of the main housing 1; the upper part of the second powder classifier 4 is provided with a second fine material outlet 41, and the lower part of the second powder classifier 4 is provided with a second coarse material outlet 42 for discharging material out of the auxiliary housing 3; the bottom of the main housing 1 is provided with a first air inlet channel 6, and the bottom of the auxiliary housing 3 is provided with a second air inlet channel 7. It should be noted that when the first classifier 2 of the particle size distribution adjustable classifier provided by this utility model is used in a vertical mill (the inner cavity of the main housing is equipped with a roller mill), the first coarse material outlet 22 does not need to extend out of the main housing, and can directly discharge coarse material to the grinding disc surface of the inner cavity of the main housing.
[0021] This application provides a particle size distribution adjustable classifier, which has multiple auxiliary shells 3 connected by an external expansion channel 5 in the main shell 1 to accommodate a second classifier 4 with different specifications than the first classifier 2. By differentiating the specifications of the first classifier 2 and the second classifier 4, the particle size distribution of the first fine material outlet 21, the first coarse material outlet 22, the second fine material outlet 41 and the second coarse material outlet 42 can be adjusted, which can be used to optimize and adjust the particle size distribution of the finished cement through subsequent mixing in different ways.
[0022] In some embodiments, in order to optimize the shape of the main housing 1 and the overall structural distribution of the device, the particle size distribution adjustable powder classifier provided by the present invention includes a frustum-shaped first housing 11 for accommodating the first powder classifier 2, a second housing 12 located below the first housing 11 and inverted cone shape, and a third housing 13 located above the first housing 11 and having a first fine material outlet 21; an external expansion channel 5 is installed on the first housing 11.
[0023] The shape of the main housing 1 is optimized, and the installation position of the expansion channel 5 is optimized. In this scheme, if the installation position of the expansion channel 5 is smoothly transitioned to the shape of the second housing 12 or is externally cut off, the working efficiency of the first air intake channel 6 configured at the bottom of the main housing 1 and the working efficiency of the second air classifier 4 will be significantly improved.
[0024] In some embodiments, in order to improve the working efficiency of the second classifier 4, the present invention provides a particle size distribution adjustable classifier device, wherein the second air inlet channel 7 includes an annular air box 71 disposed at the bottom of the auxiliary housing 3, an external air inlet 72 disposed in the annular air box 71, and an air replenishment guide channel 73 disposed inside the annular air box 71 and connected to the auxiliary housing 3; the number of air replenishment guide channels 73 is multiple.
[0025] This utility model provides an annular air box to supplement the auxiliary housing 3 with uniform airflow, further improving the working efficiency of the second air classifier 4. The second air inlet channel 7 can be equipped with a regulating valve to provide an adjustable working parameter for the second air classifier 4.
[0026] In the embodiment of the annular wind box, the air duct can be further optimized, with multiple air supply guide channels 73 all inclined to supplement the swirling airflow into the auxiliary housing 3. This utility model optimizes the guidance of the air supply guide channels 73, supplementing the auxiliary housing 3 with swirling airflow and improving the working efficiency of the second classifier 4.
[0027] The embodiments provided by this utility model should not be construed as limiting the position and number of the auxiliary housing 3 and its corresponding second classifier 4. In the particle size distribution adjustable classifier device provided by this utility model, there are multiple auxiliary housings 3, which are evenly distributed around the outer periphery of the main housing 1, and a corresponding number of second classifiers 4 are arranged inside the multiple auxiliary housings 3. This utility model provides a scheme of multiple auxiliary housings 3 cooperating with one main housing 1, which significantly increases the number of second classifiers 4 that can work simultaneously. For example, the number can be 3. Of course, it can also be 2, 4, or other numbers. Of course, the number of second classifiers 4 can also be 1.
[0028] To ensure stable feeding, this invention also provides a movable and adjustable mounting mechanism for an embodiment in which the feed inlet 8 is equipped with a screw feeder 81. The lower feeding mechanism provided by this invention preferably uses a screw feeder 81, which stabilizes the device's operation and improves work efficiency.
[0029] The adjustable particle size distribution classifier provided by this utility model can be used to widen the particle size distribution of cement vertical mills and increase the fine powder content. It can also solve the problem of narrow particle size distribution in closed-circuit grinding, and can also be used to adjust the particle size distribution of grinding, increase its fine powder content, and widen the particle size distribution.
[0030] By properly adjusting the operating parameters of the first air classifier, the second air classifier, the first blower, and the second blower, the finished cement with a high degree of particle size redistribution can be significantly improved.
[0031] This concludes the detailed description of the embodiments in conjunction with the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of this application.
[0032] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the protection scope of this application. Figure 4As shown in the present invention, the first and second air classifiers can be set up independently, with separate feeds. After sieving by the first and second air classifiers, the air and powder flow into a bag filter dust collector, where the finished cement with adjusted particle size distribution is formed. The system can be provided with negative pressure by the main fan, and a wear-resistant booster fan can be configured after the material is discharged from the second air classifier. Both the main fan and the wear-resistant booster fan can be equipped with independent valves. By adjusting the operating parameters through the valves, the controllability of particle size distribution adjustment can be further improved. The positive pressure section of the main fan can be connected to the air supply ports of the first and second air classifiers.
[0033] It should be noted that implementations not shown or described in the accompanying drawings or the main text of the specification are all forms known to those skilled in the art and are not described in detail. Furthermore, the definitions of the elements and methods described above are not limited to the various specific structures, shapes, or methods mentioned in the embodiments.
[0034] It should also be noted that this document provides examples of parameters containing specific values, but these parameters need not be exactly equal to the corresponding values, but can approximate the corresponding values within acceptable error tolerances or design constraints. Directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the accompanying drawings and are not intended to limit the scope of protection of this application. Furthermore, unless specifically described or steps must occur in sequence, the order of the above steps is not limited to those listed above and can be varied or rearranged according to the desired design. Moreover, the above embodiments can be used in combination with each other or with other embodiments based on design and reliability considerations; that is, technical features from different embodiments can be freely combined to form more embodiments.
Claims
1. A powder sorting device with adjustable particle size distribution, characterized in that, It includes a main housing (1), a first classifier (2) disposed inside the main housing (1), an auxiliary housing (3) disposed outside the main housing (1), a second classifier (4) disposed inside the auxiliary housing (3), and an external expansion channel (5) connecting the inner cavity of the main housing (1) and the inner cavity of the auxiliary housing (3); The main housing (1) is equipped with a feed inlet (8), the first classifier (2) is equipped with a first fine material outlet (21) at the top and a first coarse material outlet (22) at the bottom; the second classifier (4) is equipped with a second fine material outlet (41) at the top and a second coarse material outlet (42) at the bottom that can discharge material to the auxiliary housing (3); The main housing (1) is provided with a first air intake channel (6) at the bottom, and the auxiliary housing (3) is provided with a second air intake channel (7) at the bottom.
2. The particle size distribution adjustable powder sorting device according to claim 1, characterized in that, The main housing (1) includes a frustoconical first housing (11) for accommodating the first classifier (2), a second housing (12) located below the first housing (11) and inverted cone shape, and a third housing (13) located above the first housing (11) and having a first fine material outlet (21); the external expansion channel (5) is installed in the first housing (11).
3. The particle size distribution adjustable powder sorting device according to claim 1, characterized in that, The second air intake channel (7) includes an annular air box (71) disposed at the bottom of the auxiliary housing (3), an external air inlet (72) disposed in the annular air box (71), and an air replenishment guide channel (73) disposed inside the annular air box (71) and communicating with the auxiliary housing (3); there are multiple air replenishment guide channels (73).
4. The particle size distribution adjustable powder sorting device according to claim 3, characterized in that, Multiple air supply channels (73) are inclined to supplement the auxiliary housing (3) with swirling airflow.
5. The particle size distribution adjustable powder sorting device according to claim 1, characterized in that, The number of auxiliary shells (3) is multiple, and the multiple auxiliary shells (3) are evenly distributed around the outer periphery of the main shell (1). A corresponding number of second classifiers (4) are arranged inside the multiple auxiliary shells (3).
6. The particle size distribution adjustable powder sorting device according to claim 1, characterized in that, The feed inlet (8) is equipped with a screw feeder (81).