Improved cement grinding system

Abstract

The utility model relates to an improved cement grinding system which comprises grinding equipment and powder selecting equipment, and a powder collecting channel is communicated with the grinding equipment and the powder selecting equipment and is used for collecting powder from the powder selecting equipment by the grinding equipment; the powder feeding channel is communicated with the grinding equipment and the powder selecting equipment and is used for feeding powder to the powder selecting equipment by the grinding equipment; the powder collecting channel comprises a discharging articulated chute for conveying powder, and the discharging articulated chute is provided with a screen and used for screening out fine powder smaller than meshes of the screen from the powder fed into the grinding equipment. According to the utility model, the screen is arranged in the material receiving channel between the grinding equipment and the powder selecting equipment, so that fine powder which is not screened out by the powder selecting equipment is removed again before entering the grinding equipment, and the residual fine powder is prevented from continuously entering the grinding equipment to participate in grinding operation. Due to the fact that fine powder which is small in particle size and not suitable for the working state of the grinding equipment does not exist in the grinding operation, the working condition of the grinding equipment can be closer to the ideal state, the working efficiency of the grinding equipment is improved, and the yield of the grinding procedure is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of cement grinding, and particularly relates to an improved cement grinding system. Background Art

[0002] Since the function of the cement grinding system is not only to complete the raw material grinding, but also to obtain fine powder with the required particle size, generally speaking, the cement grinding system refers to the grinding equipment and the powder selecting equipment supporting the grinding equipment for this purpose. The actual design of the production line and the process flow are also based on this.

[0003] Figure 1 Figure 1 is a partial schematic diagram of the production line of the grinding system of the previous applicant. The material is circularly transported between the grinding equipment 1 and the powder selecting equipment 2 through the feeding chute 9. Among them, the powder selected by the powder selecting equipment 2 returns to the grinding equipment 1 again to realize re-grinding and obtain the refined and ground powder. The powder that fails to meet the standard and is not screened out by the powder selecting equipment 2 is continuously converted into qualified fine powder during the circulation between the grinding equipment 1 and the powder selecting equipment 2 and is screened out of the circulation system by the powder selecting equipment 2 to realize material transportation.

[0004] For the V-type powder selecting equipment applied on site, its technical index is to screen out fine powder particles with a particle size of 1000um. However, through the on-site detection of the circulating powder in the feeding chute 9, it is found that there is still a certain proportion of fine powder particles in the returned powder in the feeding chute 9. In other words, limited by technical conditions, it is impossible to completely screen out the fine powder in the circulating powder during powder selection.

[0005] The problem that is often overlooked is that the existence of fine powder has an impact on the operating efficiency of the grinding equipment 1. Usually, the process performance of the grinding equipment 1 and the powder selecting equipment 2 has been matched during the production line design. That is to say, for the grinding equipment, it receives larger particle size powder, obtains a part of fine powder through mechanical crushing and then is screened out by the powder selecting equipment 2. Obviously, the required fine powder particle size should not be within the range of the raw material powder particle size corresponding to the optimal working performance of the grinding equipment 1. According to on-site practice, we also indeed found that the fine powder missed by the powder selecting equipment 2 does have an impact on the operating efficiency of the grinding equipment 1. Due to the doping of fine powder in the raw material powder, the fine powder interferes with the crushing effect of the grinding surface on the large particle size powder, resulting in a reduction in the operating efficiency of 2. Content of the Utility Model

[0006] In view of the problem that in the prior art, the powder selecting equipment 2 of the grinding system cannot completely screen out fine powder, resulting in a small proportion of fine powder particles mixing into the circulating powder and re-entering the grinding equipment 1, leading to a decrease in the operating efficiency of the grinding equipment 1, the utility model provides an improved cement grinding system.

[0007] The present invention provides an improved cement grinding system, including a grinding device and a powder classifier. A powder collection channel connects the grinding device and the powder classifier for the grinding device to collect powder from the powder classifier. A powder feeding channel connects the grinding device and the powder classifier for the grinding device to feed powder to the powder classifier. The powder collection channel includes a discharge chute for conveying powder, and the discharge chute has a screen for screening out fine powder smaller than the screen mesh size from the powder fed into the grinding device.

[0008] Preferably, it includes a feeding area located below the screen for receiving fine powder that passes through the screen, and a side powder feeding channel connecting the feeding area and the powder feeding channel for conveying the fine powder in the feeding area to the powder feeding channel.

[0009] Preferably, the mesh size of the sieve is equal to or larger than the particle size of the fine powder sieved out by the powder classifier.

[0010] Preferably, the feeding chute is a non-powered conveying device with a downward inclination angle from the starting point to the ending point, and the powder falls in the feeding chute by gravity.

[0011] Preferably, the screen is divided into several segments on the feed chute.

[0012] Preferably, a wear-resistant plate is provided between adjacent segments.

[0013] This invention removes fine powder that the classifier failed to screen out before it enters the grinding equipment by installing a screen in the receiving channel between the grinding equipment and the classifier. This prevents residual fine powder from continuing to enter the grinding equipment and participating in the grinding process. Since there is no small-sized fine powder unsuitable for the grinding equipment's working conditions during the grinding process, the working conditions of the grinding equipment can be made closer to the ideal state, thereby improving the working efficiency of the grinding equipment and increasing the yield of the grinding process. Attached Figure Description

[0014] Figure 1 A partial schematic diagram of the applicant's grinding system production line;

[0015] Figure 2 This is a schematic diagram of the improved cement grinding system of this utility model;

[0016] Figure 3 This is a schematic diagram of the installation of the screen 91 of this utility model.

[0017] In the picture:

[0018] 1: Grinding equipment; 2: Powder classifier; 81: Powder collection channel; 82: Powder delivery channel; 83: Side powder delivery channel; 9: Discharge chute; 91: Screen; 92: Discharge area; 93: Wear-resistant plate. Detailed Implementation

[0019] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. In this specification, the dimensions of the drawings do not represent the actual dimensions. They are only used to illustrate the relative positional and connection relationships between the components. Components with the same name or the same reference numeral represent similar or identical structures and are limited to illustrative purposes.

[0020] Figure 2 This is a schematic diagram of the improved cement grinding system of this application. The cement grinding system includes a grinding device 1 and a classifying device 2. It also includes a receiving channel 81 and a feeding channel 82, the names of which are determined from the perspective of the grinding device 1. That is, the receiving channel 81 connects the grinding device 1 and the classifying device 2 for receiving powder from the classifying device 2, and the feeding channel 82 connects the grinding device 1 and the classifying device 2 for feeding powder from the classifying device 2. Therefore, one end of the receiving channel 81 is connected to the coarse powder outlet of the classifying device 2, for example, through a hopper at the coarse powder outlet to achieve powder conveying. The other end of the receiving channel 81 is connected to the inlet of the grinding device 1. Similarly, one end of the feeding channel 82 is connected to the outlet of the grinding device 1, and the other end is connected to the inlet of the classifying device 2. The receiving channel 81 mainly includes a discharge chute 9. The feeding chute 9 can be powered or unpowered. In this application, the feeding chute 9 is preferably unpowered. The feeding chute 9 can be an unpowered device with an inclination angle where the starting point is higher than the ending point, so that the powder falls on the feeding chute 9 by gravity.

[0021] To prevent unscreened fine powder particles from re-entering the grinding equipment 1 and affecting its operating efficiency. Figure 2 In the technical solution, a screen 91 is installed on the feed chute 9 to simply filter the fine powder from the circulating powder in the feed chute 9 a second time. Considering actual needs, the mesh size of the screen 91 should be able to remove the fine powder designed to be removed by the powder classifier 2. It can use a screen mesh size with the same particle size as the fine powder or a mesh size slightly larger than the particle size of the fine powder.

[0022] As shown in the figure, although the powder sieved is not suitable for entering the grinding equipment 1, the screen 91 also does not have the same powder selection function as the powder selection equipment 2. Therefore, the powder sieved by the screen 91 cannot be directly mixed with the fine powder obtained by the powder selection equipment 2. For this reason, a powder receiving area 92 is provided below the mesh of the screen 91 in the above-mentioned cement grinding system. A side powder feeding channel 83 is provided to connect the powder receiving area 92 and the powder feeding channel 82. The side powder feeding channel 83 is used to transport the powder in the powder receiving area 92 to the powder feeding channel 82 and mix it with the powder collection channel 81 output from the grinding equipment 1 and then transport it to the powder selection equipment 2 to undergo the powder selection operation again.

[0023] Figure 3 This is a schematic diagram of the installation of screen 91. Screen 91 can be directly fixed to the feed chute 9, generally by welding or mechanical connection. However, to ensure a good sieving effect, screen 91 needs to extend a relatively long length along the feeding direction of the feed chute 9. If the entire screen is designed as a single piece, its strength will decrease, and it will easily be damaged after a period of use. Therefore, in this embodiment, screen 91 is set in segments on the feed chute 9. Shortening the length of each screen 91 ensures its structural strength, thus relatively extending its service life. At the same time, in order to delay its wear, wear-resistant plates 93 are provided at the connection between adjacent screens 91. Wear-resistant plates 93 are ceramic wear-resistant plates in the prior art, preventing the feed powder from causing wear on the transition structure between them.

[0024] Production monitoring after the upgrade showed that the above-mentioned technical improvements significantly improved the efficiency of the cement grinding system. After the upgrade, the mill's operating time stabilized at over 310 t / h, an increase of 25 t / h compared to before the upgrade. The main motor power consumption of the cement mill decreased from 14.3 kWh / t to 11.89 kWh / t, the process power consumption decreased by 2.0 kWh / t, and the time for the mill to reach full load from start-up was shortened to less than 30 minutes. This fully demonstrates the efficiency-enhancing effect of the improved technical solution on the cement grinding system.

[0025] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of the present utility model. Any modifications and improvements made to the technical solution of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. An improved cement grinding system, characterized in that, The equipment includes a grinding device (1) and a powder classifier (2). A powder collection channel (81) connects the grinding device (1) and the powder classifier (2) for the grinding device (1) to collect powder from the powder classifier (2). A powder feeding channel (82) connects the grinding device (1) and the powder classifier (2) for the grinding device (1) to feed powder to the powder classifier (2). The powder collection channel (81) includes a discharge chute (9) for conveying powder. The discharge chute (9) has a screen (91) for screening out fine powder smaller than the mesh size of the screen (91) from the powder fed into the grinding device (1).

2. The improved cement grinding system as described in claim 1, characterized in that, It includes a feeding area (92) located below the screen (91) for receiving fine powder sieved by the screen (91), and a side powder feeding channel (83) connecting the feeding area (92) and the powder feeding channel (82) for conveying the fine powder in the feeding area (92) to the powder feeding channel (82).

3. The improved cement grinding system as described in any one of claims 1-2, characterized in that, The mesh size of the screen (91) is equal to or greater than the particle size of the fine powder screened out by the powder classifier (2).

4. The improved cement grinding system according to any one of claims 1-2, characterized in that, The feeding chute (9) is a non-powered conveying device with a downward inclination from the starting point to the ending point. The powder falls in the feeding chute (9) by gravity.

5. The improved cement grinding system as described in any one of claims 1-2, characterized in that, The screen (91) is divided into several segments on the feed chute (9) at intervals.

6. The improved cement grinding system as described in claim 5, characterized in that, The feed chute (9) has wear-resistant plates installed between adjacent sections.

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