A cement grinding process and process system for combined separation of powder classifier and settling chamber

Abstract

The present invention discloses a cement grinding process and process system for combined powder selection by a powder selector and a settling chamber, which solves the technical problems of low powder selection efficiency, high failure rate of a disintegrator, and high maintenance cost in the prior art. The process comprises a batching system (1), a feeding belt (2), a steady flow weighing bin (3), a roller press (4), a first material elevator (5), a first-stage V-type powder selector (6), a screen (7), a second-stage V-type air selector (8), a first-stage settling chamber (9), a second-stage settling chamber (10), a mill (15), and a second material elevator (16). The present invention adopts a new powder selection process to transform the existing system, reduce the number of system failure shutdowns and maintenance costs, improve the powder selection efficiency of the roller press system and the fineness of the material entering the mill, and reduce the loading capacity of the mill, thereby reducing the power consumption of the cement grinding process.

Description

Technical Field

[0001] The invention belongs to the technical field of cement production, and in particular relates to a cement grinding process and a process system for combined separation of a powder classifier and a sedimentation chamber. Background Art

[0002] The cement industry is a major energy consumer. It consumes 70-90 kW·h of electricity to produce one ton of cement, of which grinding power consumption accounts for 65%-75% of the total power consumption of cement production, and grinding costs account for about 35% of the total cost of cement production. The cement grinding process is one of the most critical factors that determine the level of cement grinding power consumption.

[0003] The development of cement grinding technology follows the concept of "more crushing and less grinding". Since the grinding efficiency of roller press is significantly higher than that of ball mill, the combined grinding process of roller press in front of ball mill has become the mainstream process. The roller press configured in the cement grinding system of cement enterprises built in the early stage is usually small in size, and adopts the "high-pressure small circulation" production mode. The clinker and mixed materials are in the form of agglomerated cakes after high-pressure grinding by roller press. In the early cement combined grinding system, the roller press system is usually equipped with a dispersing classifier to disperse and sort the roller press materials, and the sorted coarse powder is returned to the roller press for further grinding, and the sorted fine powder is sent to the mill for grinding. The main equipment of this system is roller press, dispersing machine, and ball mill. In the later period, when the specifications of roller press gradually increased, the roller press system usually adopts a large V-type powder classifier to disperse and sort the materials out of the roller press. The main equipment of this system is roller press, V-type powder classifier, ball mill, etc. At present, there are still many cement combined grinding systems equipped with dispersing classifiers in China.

[0004] The applicant has found that the prior art has at least the following technical problems:

[0005] 1. Low powder selection efficiency: Usually the powder selection efficiency of the scattering and classifying machine is 50-60%.

[0006] 2. The failure rate of the disintegrator is high and the maintenance cost is high: the screen plate is used for disintegration and sorting, and the screen plate is often blocked, affecting continuous production. The screen plate is easily eroded and worn by the material, which affects the powder selection efficiency. The maintenance and repair workload is large and the cost of accessories is high.

[0007] 3. The semi-finished product of the roller press system is the coarse fineness of the material entering the mill: the material R80μm entering the mill using the disintegrator system is usually as high as 40-50%, and the specific surface area is relatively low, usually 120-160m 2 / kg. This results in coarse materials entering the mill, which leads to the need to configure larger steel balls in the mill, higher mill load, and higher power consumption for cement grinding. In addition, it is difficult to transform this type of cement joint system equipped with a disintegrator into a large V-type powder selector system, because the space and weighing of the original system cannot meet the transformation requirements, resulting in high transformation costs. Summary of the invention

[0008] In view of the shortcomings of the existing cement combined grinding process system equipped with a scattering classifier, the present invention proposes a cement grinding process and process system with a two-stage V-type powder classifier connected in series and a sedimentation chamber for combined classification. The main purpose is to adopt a new powder selection process to transform the existing system, reduce the number of system failure shutdowns and maintenance costs, improve the powder selection efficiency of the roller press system and the fineness of the material entering the mill, reduce the mill loading capacity, and thus reduce the power consumption of the cement grinding process.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] The present invention provides a cement grinding process system for combined separation of powder selector and sedimentation chamber, comprising a batching system, a feeding belt, a steady flow weighing bin, a roller press, a first material elevator, a first-stage V-type powder selector, a screen, a second-stage V-type powder selector, a first-stage sedimentation chamber, a second-stage sedimentation chamber, a mill, and a second material elevator; wherein,

[0011] The batching system is connected to the feed port of the steady flow weighing bin, a feeding belt is arranged between the batching system and the steady flow weighing bin, the discharge port of the steady flow weighing bin is connected to the feed port of the roller press, the discharge port of the roller press is connected to the feed port of the first material elevator, the discharge port of the first material elevator is connected to the feed port of the first-level V-type powder classifier, the first outlet of the first-level V-type powder classifier is connected to the screen, the second outlet of the first-level V-type powder classifier is connected to the first-level sedimentation chamber, the outlet of the first-level sedimentation chamber is connected to the inlet of the mill, the first outlet of the screen is connected to the feed port of the second-level V-type powder classifier, the second outlet of the screen is connected to the steady flow weighing bin, the first outlet of the second-level V-type powder classifier is connected to the inlet of the second-level sedimentation chamber, the second outlet of the second-level V-type powder classifier is connected to the steady flow weighing bin, the outlet of the second-level sedimentation chamber is connected to the inlet of the mill, and the outlet of the mill is connected to the inlet of the second material elevator.

[0012] Furthermore, it also includes a primary dust collector, a secondary dust collector, and a tail dust collector. The primary dust collector is connected to the air outlet direction of the primary settling chamber, the secondary dust collector is connected to the air outlet direction of the secondary settling chamber, and the tail dust collector is connected to the air outlet direction of the grinder.

[0013] Furthermore, it also includes a first-level powder selection system ventilation fan, a second-level powder selection system ventilation fan, and a grinder ventilation fan. The first-level powder selection system ventilation fan is connected to the air outlet direction of the first-level dust collector, the second-level powder selection system ventilation fan is connected to the air outlet direction of the second-level dust collector, and the grinder ventilation fan is connected to the air outlet direction of the dust collector at the end of the grinding mill.

[0014] Furthermore, the first-stage V-type powder classifier and the second-stage V-type powder classifier are connected in series.

[0015] Furthermore, the volume of the first-stage V-type powder concentrator is 10 to 20 m3 The air volume of the first-level powder selection system ventilation fan is 50000~70000m 3 / h.

[0016] Furthermore, the volume of the secondary V-type powder concentrator is 5 to 10 m 3 The air volume of the secondary powder selection system ventilation fan is 20000~30000m 3 / h.

[0017] Furthermore, the sieve mesh slits are set at 5 to 10 mm.

[0018] The present invention provides a cement grinding process for combined separation of a powder classifier and a settling chamber, comprising the following steps:

[0019] Step 1: The raw materials are weighed in the batching system and then enter the steady flow weighing bin through the feeding belt;

[0020] Step 2: The material passes through the steady flow weighing bin and is fed into the roller press for grinding;

[0021] Step 3: After exiting the roller press, the material is lifted by the material elevator and then enters the first-stage V-type powder concentrator;

[0022] Step 4: After powder selection, the coarse powder enters the screen, and the selected fine powder enters the grinding mill after gravity sedimentation in the primary settling chamber. The primary V-type powder selector, the primary settling chamber, and the primary dust collector system are equipped with a primary powder selection system ventilation fan. The material entering the screen is sorted, and the coarse particles enter the steady flow weighing bin, and the fine particles enter the secondary V-type powder selector;

[0023] Step 5: After the secondary V-type powder concentrator is used for concentrating, the coarse powder returns to the steady flow weighing bin, and the fine powder enters the grinding mill after gravity settling in the secondary settling chamber. The secondary V-type powder concentrator, secondary settling chamber, and secondary dust collector system are equipped with a secondary powder concentrating system ventilation fan;

[0024] Step 6: After the material enters the mill and is ground, it passes through the material elevator and enters the finished product.

[0025] Based on the above technical solution, the embodiments of the present invention can at least produce the following technical effects:

[0026] (1) The cement grinding process and process system of the powder classifier and the settling chamber combined with the powder classifier provided by the present invention has a low system failure rate compared with the original sintering classifier process, and reduces the system maintenance time and maintenance cost.

[0027] (2) The cement grinding process and process system of the powder selector and sedimentation chamber combined separation provided by the present invention, the materials leaving the roller press are subjected to two-stage disintegration and separation, the powder selection efficiency of the system is increased to more than 70%, the semi-finished product fineness of the roller press system is fine, the R80μm of the materials entering the mill is reduced to less than 20%, and the specific surface area is greater than 200m 2 / kg, which can significantly reduce the grinding media loading of the mill and reduce the power consumption of the cement grinding process by 2 to 4 kWh / t.

[0028] (3) The cement grinding process and process system with a powder selector and a settling chamber combined for separation provided by the present invention is to transform the combined grinding system with the original disintegrator, without the need to transform and reinforce the original civil engineering structure, and the transformation cost is low. The roller press system is equipped with a small amount of air for powder selection, and the conventional single large V-type powder selector is equipped with a fan with an air volume of 150,000 to 300,000 m 3 / h, the total air volume of the two fans configured in the system of the present invention is less than 100000m 3 / h, which is beneficial to reducing the system fan configuration power and reducing the fan power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention 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 present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0030] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0031] In the above drawings, the component names corresponding to the reference numerals are as follows:

[0032] 1. Batching system; 2. Feeding belt; 3. Steady flow weighing bin; 4. Roller press; 5. Material elevator 1; 6. Primary V-type powder classifier; 7. Screen; 8. Secondary V-type powder classifier; 9. Primary settling chamber; 10. Secondary settling chamber; 11. Primary dust collector; 12. Secondary dust collector; 13. Ventilation fan for primary powder classifier system; 14. Ventilation fan for secondary powder classifier system; 15. Grinding mill; 16. Material elevator 2; 17. Dust collector at the end of grinding mill; 18. Ventilation fan for grinding mill. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0035] The objective of the present invention is achieved through the following technical solutions:

[0036] like Figure 1 As shown, a case study of the transformation of a combined grinding system equipped with a scattering classifier is used to illustrate the invention. The system is equipped with a 160-140 roller press and a Φ4.2*13m ball mill. The materials discharged from the roller press are screened by the scattering machine. The scattering machine frequently fails and leaks, seriously affecting continuous production. When producing PO42.5 cement, the output is only 130-140t / h, and the process power consumption is 28-29kWh / t.

[0037] The present invention transforms the grinding system, removes the pulverizer in the roller press system, adds a two-stage V-type powder selector and a settling chamber combined sorting system and a settling chamber, uses the dust collector and dust collecting fan of the original pulverizer as the primary dust collector and fan, and adds the dust collector and fan of the secondary powder selection system. The transformation process does not require changes to the original plant structure.

[0038] A cement grinding process system with a powder selector and a sedimentation chamber for combined separation, comprising a batching system 1, a feeding belt 2, a steady flow weighing bin 3, a roller press 4, a material elevator 1 5, a first-stage V-type powder selector 6, a screen 7, a second-stage V-type powder selector 8, a first-stage sedimentation chamber 9, a second-stage sedimentation chamber 10, a grinding machine 15, and a second material elevator 16; wherein,

[0039] The batching system 1 is connected to the feed port of the steady flow weighing bin 3, a feeding belt 2 is arranged between the batching system 1 and the steady flow weighing bin 3, the discharge port of the steady flow weighing bin 3 is connected to the feed port of the roller press 4, the discharge port of the roller press 4 is connected to the feed port of the material elevator 5, the discharge port of the material elevator 5 is connected to the feed port of the first-level V-type powder selector 6, the first outlet of the first-level V-type powder selector 6 is connected to the screen 7, the second outlet of the first-level V-type powder selector 6 is connected to the first-level sedimentation chamber 9, and the first-level V-type powder selector 6 is connected to the first-level sedimentation chamber 9. The outlet of the first settling chamber 9 is connected to the inlet of the grinder 15, the first outlet of the screen 7 is connected to the feed port of the second V-type powder classifier 8, the second outlet of the screen 7 is connected to the steady flow weighing bin 3, the first outlet of the second V-type powder classifier 8 is connected to the inlet of the second settling chamber 10, the second outlet of the second V-type powder classifier 8 is connected to the steady flow weighing bin 3, the outlet of the second settling chamber 10 is connected to the inlet of the grinder 15, and the outlet of the grinder 15 is connected to the inlet of the material elevator 16.

[0040] It also includes a primary dust collector 11, a secondary dust collector 12, and a tail dust collector 17. The primary dust collector 11 is connected to the air outlet direction of the primary settling chamber 9, the secondary dust collector 12 is connected to the air outlet direction of the secondary settling chamber 10, and the tail dust collector 17 is connected to the air outlet direction of the grinder 15.

[0041] It also includes a primary powder selection system ventilation fan 13, a secondary powder selection system ventilation fan 14, and a grinder ventilation fan 18. The primary powder selection system ventilation fan 13 is connected to the air outlet direction of the primary dust collector 11, the secondary powder selection system ventilation fan 14 is connected to the air outlet direction of the secondary dust collector 12, and the grinder ventilation fan 18 is connected to the air outlet direction of the grinding tail dust collector 17.

[0042] In a specific embodiment, the primary V-type powder classifier 6 and the secondary V-type powder classifier 8 are connected in series.

[0043] In a specific embodiment, the volume of the first-stage V-type powder concentrator 6 is 15m 3 , the air volume of the first-stage powder selection system ventilation fan 13 is 60000m 3 / h.

[0044] In a specific embodiment, the volume of the secondary V-type powder separator 8 is 8m 3 , the air volume of the secondary powder selection system ventilation fan 14 is 30000m 3 / h.

[0045] In a specific embodiment, the grating of the screen 7 is set at 8mm.

[0046] After the transformation, the system process flow is described as follows according to the material flow in the process flow chart: the raw materials are weighed in the batching system 1 in sequence and then enter the steady flow weighing bin 3 through the feeding belt 2. The materials are fed into the roller press 4 for grinding after passing through the steady flow weighing bin 3. After exiting the roller press 4, the materials are lifted by the material elevator 5 and then enter the first-level V-type powder selector 6. After powder selection, the coarse powder enters the screen 7. The selected fine powder enters the grinding mill 15 after gravity sedimentation in the first-level sedimentation chamber 9. The first-level V-type powder selector 6, the first-level sedimentation chamber 9, and the first-level dust collector 11 system are equipped with A first-level powder selection system ventilation fan 13 is provided. The material entering the screen 7 is sorted, and the coarse particles enter the steady flow weighing bin 3, and the fine particles enter the second-level V-type powder selector 8; after sorting in the second-level V-type powder selector 8, the coarse powder returns to the steady flow weighing bin 3, and the fine powder enters the grinding mill 15 after gravity sedimentation in the second-level sedimentation chamber 10. The second-level V-type powder selector 8 and the second-level sedimentation chamber 10, the second-level dust collector 12 system are equipped with a second-level powder selection system ventilation fan 14; the material enters the grinding mill 15 and is ground, and then passes through the material elevator 16 to enter the finished product.

[0047] After the system was transformed by the present invention, the production of PO42.5 cement could reach 180-190t / h, and the power consumption of the process was only 23-24kW·h / t, which was 50t / h higher than the original process, and the power consumption was reduced by about 5kW·h / t, achieving significant energy saving and carbon reduction benefits. Using this process, the system measured a two-stage separation efficiency of 82%, the R80μm of the material entering the mill was 15%-20%, and the specific surface area reached 200-210m 2 / kg, the grinding ball loading of the mill is reduced by about 30t, which provides the necessary conditions for reducing the power consumption of the mill.

[0048] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of the present invention to be protected is defined by the attached claims and their equivalents.

Claims

1. A cement grinding process system with a powder concentrator and a settling chamber for combined sorting, characterized in that: It includes a batching system (1), a feeding belt (2), a steady flow weighing bin (3), a roller press (4), a material elevator 1 (5), a first-stage V-type powder classifier (6), a screen (7), a second-stage V-type powder classifier (8), a first-stage sedimentation chamber (9), a second-stage sedimentation chamber (10), a grinding mill (15), and a second material elevator (16); wherein: The batching system (1) is connected to the feed port of the steady flow weighing bin (3), a feeding belt (2) is arranged between the batching system (1) and the steady flow weighing bin (3), the discharge port of the steady flow weighing bin (3) is connected to the feed port of the roller press (4), the discharge port of the roller press (4) is connected to the feed port of the material elevator (5), the discharge port of the material elevator (5) is connected to the feed port of the first V-type powder selector (6), the coarse powder outlet of the first V-type powder selector (6) is connected to the screen (7) The fine powder outlet of the first V-shaped powder classifier (6) is connected to the first settling chamber (9), the outlet of the first settling chamber (9) is connected to the inlet of the grinding mill (15), the fine particle outlet of the screen (7) is connected to the feed inlet of the second V-shaped powder classifier (8), the coarse particle outlet of the screen (7) is connected to the steady flow weighing bin (3), the fine powder outlet of the second V-shaped powder classifier (8) is connected to the inlet of the second settling chamber (10), and the coarse powder outlet of the second V-shaped powder classifier (8) is connected to the feed inlet of the second V-shaped powder classifier (8). The first-stage settling chamber (9) is connected to a steady-flow weighing bin (3), the outlet of the second-stage settling chamber (10) is connected to an inlet of a grinding mill (15), and the outlet of the grinding mill (15) is connected to an inlet of a second material elevator (16); the first-stage dust collector (11), the second-stage dust collector (12), and a grinding tail dust collector (17), wherein the first-stage dust collector (11) is connected to an air outlet direction of the first-stage settling chamber (9), the second-stage dust collector (12) is connected to an air outlet direction of the second-stage settling chamber (10), and the grinding tail dust collector (17) is connected to an air outlet direction of the second-stage settling chamber (10). 7) connected in the direction of the air outlet of the grinding mill (15); and further comprising a primary powder selection system ventilation fan (13), a secondary powder selection system ventilation fan (14), and a grinding mill ventilation fan (18); the primary powder selection system ventilation fan (13) is connected in the direction of the air outlet of the primary dust collector (11), the secondary powder selection system ventilation fan (14) is connected in the direction of the air outlet of the secondary dust collector (12), and the grinding mill ventilation fan (18) is connected in the direction of the air outlet of the grinding tail dust collector (17).

2. The cement grinding process system with combined separation of powder concentrator and settling chamber according to claim 1 is characterized in that: The first-stage V-shaped powder classifier (6) and the second-stage V-shaped powder classifier (8) are connected in series.

3. The cement grinding process system with combined separation of powder concentrator and settling chamber according to claim 1 is characterized in that: The volume of the first-stage V-type powder concentrator (6) is 10 to 20 m 3 The air volume of the first-stage powder selection system ventilation fan (13) is 50000~70000m 3 / h.

4. The cement grinding process system with combined separation of powder concentrator and settling chamber according to claim 1 is characterized in that: The volume of the second-stage V-type powder separator (8) is 5 to 10 m 3 The air volume of the secondary powder selection system ventilation fan (14) is 20000~30000m 3 / h.

5. The cement grinding process system with combined separation of powder concentrator and settling chamber according to claim 1 is characterized in that: The grating of the screen (7) is set at 5 to 10 mm.

6. A cement grinding process with a powder classifier and a settling chamber for combined separation, characterized in that: A cement grinding process system using the powder classifier and the settling chamber for combined separation according to any one of claims 1 to 5 comprises the following steps: Step 1: The raw materials are weighed in the batching system (1) and then enter the steady flow weighing bin (3) through the feeding belt (2); Step 2: the material passes through the steady flow weighing bin (3) and is then fed into the roller press (4) for grinding; Step 3: After exiting the roller press (4), the material is lifted by the material elevator 1 (5) and then enters the first-stage V-type powder separator (6). Step 4: After the powder is selected, the coarse powder enters the screen (7), and the selected fine powder passes through the first-level sedimentation chamber (9) and then enters the grinding mill (15) by gravity sedimentation. The first-level V-type powder selector (6), the first-level sedimentation chamber (9), and the first-level dust collector (11) are equipped with a first-level powder selection system ventilation fan (13). The material entering the screen (7) is sorted, and the coarse particles enter the steady flow weighing bin (3), and the fine particles enter the second-level V-type powder selector (8); Step 5: After being sorted by the secondary V-shaped powder classifier (8), the coarse powder returns to the steady flow weighing bin (3), and the fine powder is gravity-sedimented through the secondary settling chamber (10) and then enters the grinding mill (15). The secondary V-shaped powder classifier (8), the secondary settling chamber (10), and the secondary dust collector (12) are equipped with a secondary powder selection system ventilation fan (14); Step 6: The material enters the grinding mill (15) and is ground, then passes through the second material elevator (16) and enters the finished product.

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