Device and method for reducing moisture of cement by using tail exhaust air

Abstract

The application discloses a device and method for reducing cement moisture by using tail exhaust air, which comprises a conveying member and an air supply member, the feeding end of the conveying member is connected with the discharge port of a cement mill, and the discharging end is connected with a storage library; the air supply member comprises a lifting air assembly, a fluidizing air assembly and a tail exhaust air assembly, the fluidizing air assembly is connected with the conveying member in communication; the lifting air assembly is connected with the feeding end of the conveying member; the air inlet end of the tail exhaust air assembly is connected with the exhaust air pipeline of the cement mill, and the two air outlet ends are respectively connected with the fluidizing air assembly and the lifting air assembly in communication; the tail exhaust air in the exhaust air pipeline of the cement mill is introduced into the fluidizing air assembly and the lifting air assembly through the tail exhaust air assembly, so that the tail exhaust air is combined with the fluidizing air and the lifting air respectively and then is introduced into the conveying member, the residual moisture of the cement is reduced by using the waste heat of the tail exhaust air, the early hydration reaction of the cement is reduced, the activity of the cement particles is maintained, the setting time is restored to normal, the strength of each age period is maintained, and therefore the quality of the finished cement is improved.

Description

Technical Field

[0001] This invention relates to the field of cement production equipment technology, and in particular to a device and method for reducing the moisture content of cement using exhaust air. Background Technology

[0002] Cement is a powdered hydraulic binder that hardens and forms a strong, stone-like substance after a chemical reaction with water. In the production of general-purpose Portland cement, auxiliary materials such as slag, fly ash, or gypsum are often added to adjust cement performance or reduce costs. These materials often carry naturally adhering moisture, which is difficult to completely remove even after hot air drying in the grinding system. This residual moisture is inevitably produced along with the finished cement. When this finished cement is transported to the storage warehouse via an air conveyor chute, the moisture it carries continues to contact the cement particles during transport and in the initial stage of storage. This causes premature hydration before the cement reaches the construction and use stage, resulting in reduced cement particle activity, abnormal setting time, and a significant decrease in strength at all ages, ultimately leading to a decline in the quality of the finished cement. Summary of the Invention

[0003] This application provides an apparatus and method for reducing cement moisture by using exhaust air. By introducing the exhaust air discharged from the cement mill into the cement conveying process, the waste heat of the exhaust air is used to dry the cement during conveying, thereby reducing the residual moisture in the cement, reducing the premature hydration reaction caused by the presence of moisture in the cement during the initial conveying and storage stages, thus maintaining the activity of cement particles, restoring the setting time to normal, and maintaining the strength at all ages, thereby improving the quality of the finished cement.

[0004] In a first aspect, this application provides a device for reducing cement moisture using exhaust air, comprising a conveying component and an air supply component. The inlet end of the conveying component is connected to the outlet of a cement mill, and the outlet end is connected to a storage tank to convey cement from the cement mill to the storage tank. The air supply component includes a lifting air assembly, a fluidizing air assembly, and an exhaust air assembly. The fluidizing air assembly is connected to the conveying component and is used to introduce fluidizing air into the conveying component to fluidize the cement within the conveying component. The lifting air assembly is connected to the inlet end of the conveying component and is used to introduce lifting air into the inlet end of the conveying component to suspend and flow the cement. The inlet end of the exhaust air assembly is connected to the exhaust duct of the cement mill to introduce the exhaust air from the cement mill. The two outlet ends are respectively connected to the fluidizing air assembly and the lifting air assembly, so that the exhaust air is combined with the fluidizing air generated by the fluidizing air assembly and the lifting air generated by the lifting air assembly before being introduced into the conveying component to reduce the moisture content of the cement during the conveying process.

[0005] Preferably, the conveying component includes a conveying chute, a permeable layer, and a partition. The permeable layer is disposed within the conveying chute to divide the chute into an upper material conveying chamber and a lower air chamber. The partition is disposed within the air chamber to divide the air chamber into a front air chamber and a rear air chamber along the material conveying direction. The front air chamber is located at the feed end of the conveying chute, and the rear air chamber is located behind the front air chamber and extends along the conveying direction of the conveying chute to the discharge end. The front air chamber is connected to the lifting air assembly to introduce a first mixed air, which is a combination of lifting air and exhaust air, and allows the first mixed air to enter the material conveying chamber through the permeable layer, causing the cement to suspend and flow at the feed end of the conveying chute. The rear air chamber is connected to the fluidizing air assembly to introduce a second mixed air, which is a combination of fluidizing air and exhaust air, and allows the second mixed air to enter the material conveying chamber through the permeable layer, causing the cement to fluidize within the conveying chute.

[0006] Preferably, the lifting air assembly includes a lifting air duct and a first fan. The two air inlets of the lifting air duct are respectively connected to the first fan and the tail exhaust air assembly, and the air outlet of the lifting air duct is connected to the front air chamber so as to uniformly introduce the first mixed air into the front air chamber, so that the cement is suspended and flows at the feed end of the conveying chute.

[0007] Preferably, the fluidizing air assembly includes a fluidizing air main pipe, a second fan, and at least two fluidizing air branch pipes. The fluidizing air main pipe is located below the conveying chute and is arranged along the conveying direction of the conveying chute. The two air inlets of the fluidizing air main pipe are respectively connected to the second fan and the tail exhaust assembly. Each fluidizing air branch pipe is arranged at intervals along the conveying direction of the conveying chute, with one end connected to the fluidizing air main pipe and the other end connected to the rear air chamber, so as to uniformly introduce the second mixing air into the rear air chamber, so that the cement is fluidized in the conveying chute.

[0008] Preferably, the exhaust assembly includes an exhaust duct, a tee connector, a first butterfly valve, and a second butterfly valve. One end of the exhaust duct is connected to the exhaust pipe of the cement mill, and the other end is connected to the inlet end of the tee connector. The two outlet ends of the tee connector are respectively connected to the inlet end of the fluidizing air main and the inlet end of the lifting air duct, so as to introduce the exhaust air of the cement mill into the fluidizing air main and the lifting air duct respectively. The first butterfly valve is set on the pipeline between the tee connector and the lifting air duct to regulate the exhaust air entering the lifting air duct. The second butterfly valve is set on the pipeline between the tee connector and the fluidizing air main to regulate the exhaust air entering the fluidizing air main.

[0009] Secondly, this application provides a method for reducing the moisture content of cement, which is based on the apparatus for reducing the moisture content of cement using exhaust air as described in the first aspect, and includes the following steps: S1, introduces exhaust air and splits it into first exhaust air and second exhaust air; S2, which combines the first exhaust air and the lifting air into the first mixed air, and the second exhaust air and the fluidizing air into the second mixed air; S3, the first and second mixing air are introduced into the conveying component to reduce the moisture content of the cement during the conveying process.

[0010] Preferably, step S1 includes: S101, the exhaust air discharged from the cement mill is led out through the exhaust duct; S102, the exhaust air is split into the first exhaust air and the second exhaust air through the tee joint.

[0011] Preferably, step S2 includes: S201, the first tail exhaust air is controlled by the first butterfly valve to enter the lifting air duct at the first predetermined air pressure, and is combined with the lifting air output by the first fan to form the first mixed air; S202, the second tail exhaust air is controlled by the second butterfly valve to enter the fluidizing air main pipe at the second predetermined air pressure, and is combined with the fluidizing air output by the second fan to form the second mixed air.

[0012] Preferably, both the first predetermined wind pressure and the second predetermined wind pressure are 1200Pa to 1800Pa.

[0013] Preferably, step S3 includes: S301, the first mixed air enters the front air chamber along the lifting air duct, and then passes through the permeable layer into the material conveying chamber, so that the cement is suspended and flowed at the feed end of the conveying chute and is heated and dehydrated. S302, the second mixing air first enters each fluidizing air branch pipe along the main fluidizing air pipe, then enters the rear air chamber, and then passes through the permeable layer into the material conveying chamber, so that the cement is fluidized and heated and dehydrated in the conveying chute.

[0014] As can be seen from the above technical solutions, the device and method for reducing cement moisture by using exhaust air provided in this application introduces the exhaust air from the cement mill exhaust duct into the fluidizing air assembly and the lifting air assembly through the exhaust air assembly. The exhaust air is then combined with the fluidizing air generated by the fluidizing air assembly and the lifting air generated by the lifting air assembly and then introduced into the conveying component. The waste heat of the exhaust air is used to dry the cement during conveying, reduce the residual moisture in the cement, reduce the premature hydration reaction of the cement due to the presence of moisture in the early stage of conveying and storage, thereby maintaining the activity of cement particles, restoring the setting time to normal, and maintaining the strength at all ages, thereby improving the quality of the finished cement.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: By setting up a tail exhaust fan assembly, the tail exhaust fan discharged from the cement mill is introduced into the fluidizing air assembly and the lifting air assembly, so that the tail exhaust fan, fluidizing air and lifting air are combined and then introduced into the conveying component. During the conveying process, the cement is dried, which effectively reduces the residual moisture in the cement, reduces the premature hydration reaction of the cement, maintains the activity of cement particles, improves the setting time and strength at all ages, thereby improving the quality of the finished cement. At the same time, the waste heat of the tail exhaust fan is fully utilized, eliminating the need for an additional heat source and reducing energy consumption.

[0016] In summary, the device and method for reducing cement moisture using exhaust air provided in this application introduce the exhaust air discharged from the cement mill into the fluidizing air assembly and the lifting air assembly. The exhaust air is then combined with the fluidizing air generated by the fluidizing air assembly and the lifting air generated by the lifting air assembly before being introduced into the conveying component. The waste heat of the exhaust air is used to reduce the moisture content of the cement during the conveying process, thereby reducing premature hydration reaction of the cement, maintaining the activity of cement particles, restoring the setting time to normal, and maintaining the strength at each age, thus improving the quality of the finished cement. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a device for reducing cement moisture using exhaust air, as proposed in this invention. Figure 2 This is another perspective of the structural schematic diagram of a device for reducing cement moisture using exhaust air proposed in this invention; Figure 3 This is a cross-sectional view of a device for reducing cement moisture using exhaust air, as proposed in this invention. The diagram shows: a device for reducing cement moisture using exhaust air 10, a conveying component 20, a conveying chute 21, a permeable layer 22, a partition 23, an air supply component 30, a lifting air assembly 31, a lifting air duct 311, a first fan 312, a fluidizing air assembly 32, a fluidizing air main duct 321, a second fan 322, a fluidizing air branch duct 323, an exhaust air assembly 33, an exhaust air duct 331, a tee connector 332, a first butterfly valve 333, and a second butterfly valve 334. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0020] See Figure 1In one aspect, this application provides a device 10 for reducing cement moisture using exhaust air, comprising a conveying component 20 and an air supply component 30. The inlet end of the conveying component 20 is connected to the outlet of a cement mill, and the outlet end is connected to a storage tank to convey cement from the cement mill to the storage tank. The air supply component 30 includes a lifting air assembly 31, a fluidizing air assembly 32, and an exhaust air assembly 33. The fluidizing air assembly 32 is connected to the conveying component 20 and is used to introduce fluidizing air into the conveying component 20, causing the cement in the conveying component 20 to become fluidized. The lifting air assembly 31 is connected to the inlet end of the conveying component 20 and is used to introduce lifting air into the inlet end of the conveying component 20, causing the cement to suspend and flow. The inlet end of the exhaust air assembly 33 is connected to the exhaust pipe of the cement mill to introduce the exhaust air from the cement mill, and the two outlet ends are respectively connected to the flow... The fluidizing air assembly 32 and the lifting air assembly 31 are connected, so that the exhaust air is combined with the fluidizing air generated by the fluidizing air assembly 32 and the lifting air generated by the lifting air assembly 31 before being introduced into the conveying component 20, thereby reducing the moisture content of the cement during the conveying process. Specifically, the exhaust air in the cement mill exhaust pipe is introduced into the fluidizing air assembly 32 and the lifting air assembly 31 through the exhaust air assembly 33, so that the exhaust air is combined with the fluidizing air generated by the fluidizing air assembly 32 and the lifting air generated by the lifting air assembly 31 before being introduced into the conveying component 20. The waste heat of the exhaust air is used to dry the cement during the conveying process, reducing the residual moisture in the cement, reducing the premature hydration reaction caused by the presence of moisture in the cement during the initial conveying and storage stages, thereby maintaining the activity of cement particles, restoring the setting time to normal, and maintaining the strength at each age, thereby improving the quality of the finished cement.

[0021] See Figure 3In this invention, the conveying component 20 includes a conveying chute 21, a permeable layer 22, and a partition 23. The permeable layer 22 is disposed within the conveying chute 21 to divide the conveying chute 21 into an upper material conveying chamber and a lower air chamber. The partition 23 is disposed within the air chamber to divide the air chamber into a front air chamber and a rear air chamber along the material conveying direction. The front air chamber is located at the feed end of the conveying chute 21, and the rear air chamber is located behind the front air chamber and extends along the conveying direction of the conveying chute 21 to the discharge end. The front air chamber and the lifting air assembly... The conveyor chute 21 is connected to the fluidizing air assembly 32 to introduce a first mixed airflow, which combines the lifting air and the exhaust air. This first mixed airflow passes through the permeable layer 22 and enters the material conveying chamber, causing the cement to suspend and flow at the feed end of the conveying chute 21. The rear air chamber is connected to the fluidizing air assembly 32 to introduce a second mixed airflow, which combines the fluidizing air and the exhaust air. This second mixed airflow passes through the permeable layer 22 and enters the material conveying chamber, causing the cement to fluidize within the conveying chute 21. Specifically, the conveying chute 21 is used to convey finished cement from the discharge end of the cement mill to the storage warehouse. The permeable layer 22 is located inside the conveying chute 21, with the material conveying chamber above it for conveying materials and the air chamber below it for circulating air supply. The air chamber is divided into a front air chamber and a rear air chamber along the material conveying direction by a partition 23. The front air chamber is located at the feed end of the conveying chute 21 and receives the first mixed air provided by the lifting air assembly 31. The rear air chamber is located behind the front air chamber and extends to the discharge end, receiving the second mixed air provided by the fluidizing air assembly 32. The first and second mixed air pass through the front and rear air chambers, respectively, through the permeable layer 22, and enter the material conveying chamber, realizing the suspension flow of the material at the front end of the conveying chute 21 and the fluidized conveying in the rear section, respectively. The beneficial effect is that by dividing the air chamber into two independent functional areas by the partition 23, the lifting air and fluidizing air can be controlled independently in each area. This ensures that the material at the feed end is fully suspended to eliminate the accumulation layer, and maintains the fluidization stability of the rear conveying section. The synergistic effect of the two significantly prolongs the contact time between the material and the hot air, improving the evaporation efficiency.

[0022] In this embodiment, the breathable layer 22 is made of a porous breathable material, such as polyester breathable cloth, ceramic porous plate and microporous sintered plate, so that the first mixed air and the second mixed air can pass through the breathable layer 22 evenly into the material conveying chamber, and support the cement material to prevent cement particles from falling into the air chamber.

[0023] See Figure 1In this invention, the lifting air assembly 31 includes a lifting air duct 311 and a first fan 312. The two air inlets of the lifting air duct 311 are respectively connected to the first fan 312 and the tail exhaust assembly 33. The air outlet of the lifting air duct 311 is connected to the front air chamber to uniformly introduce the first mixed air into the front air chamber, so that the cement is suspended and flows at the feed end of the conveying chute 21. Specifically, the first fan 312 is the original 4kW chute fan, which is used to generate room temperature lifting air. One end of the lifting air duct 311 is connected to the air outlet of the first fan 312, and the other end is connected to one air outlet of the tail exhaust assembly 33. The air outlet of the lifting air duct 311 is connected to the front air chamber. The lifting air generated by the first blower 312 and the first exhaust air introduced by the tail exhaust assembly 33 are combined into a first mixed air in the lifting duct 311. This first mixed air is then evenly sent into the front air chamber through the outlet end of the lifting duct 311, ensuring that the cement material obtains sufficient levitation force at the feed end of the conveying chute 21. Its beneficial effects are: by combining the tail exhaust air with the original lifting blower airflow, the air volume at the feed end is significantly increased. The hot air directly acts on the material just entering the chute, starting to disturb and heat the material in the densest area of ​​accumulation, breaking the water vapor-sealed environment from the source, and effectively improving the front-end dewatering efficiency.

[0024] See Figure 1In this invention, the fluidizing air assembly 32 includes a fluidizing air main pipe 321, a second fan 322, and at least two fluidizing air branch pipes 323. The fluidizing air main pipe 321 is located below the conveying chute 21 and is arranged along the conveying direction of the conveying chute 21. The two air inlets of the fluidizing air main pipe 321 are respectively connected to the second fan 322 and the tail exhaust assembly 33. Each fluidizing air branch pipe 323 is arranged at intervals along the conveying direction of the conveying chute 21, with one end connected to the fluidizing air main pipe 321 and the other end connected to the rear air chamber, so as to uniformly introduce the second mixing air into the rear air chamber, so that the cement is fluidized in the conveying chute 21. Specifically, the second fan 322 is the original 4kW chute fan, used to generate normal temperature fluidizing air. The fluidizing air main pipe 321 is located below the conveying chute 21, and its air inlet is respectively connected to the air outlet of the second fan 322 and one air outlet of the tail exhaust assembly 33. Multiple fluidizing air branch pipes 323 are connected at intervals along the conveying direction to the main fluidizing air pipe 321, and the other end of each fluidizing air branch pipe 323 is connected to the rear air chamber. The fluidizing air generated by the second blower 322 and the second exhaust air introduced by the exhaust air assembly 33 are combined into a second mixed air in the main fluidizing air pipe 321. This second mixed air is then evenly distributed and sent into the rear air chamber through each fluidizing air branch pipe 323, ensuring that the cement material maintains a stable fluidized state in the rear section of the conveying chute 21. Its beneficial effects are: by evenly distributing hot air to each section of the rear air chamber through multiple fluidizing air branch pipes 323 arranged at intervals along the flow path, the uniformity and stability of the material fluidization in the entire conveying chute 21 are guaranteed, avoiding local accumulation or blow-through phenomena. At the same time, it expands the effective contact area between hot air and material, allowing the dewatering process to continue in the rear section.

[0025] See Figure 1 and Figure 2In this invention, the exhaust assembly 33 includes an exhaust duct 331, a tee connector 332, a first butterfly valve 333, and a second butterfly valve 334. One end of the exhaust duct 331 is connected to the exhaust pipe of the cement mill, and the other end is connected to the inlet end of the tee connector 332. The two outlet ends of the tee connector 332 are respectively connected to the inlet end of the fluidizing air main duct 321 and the inlet end of the lifting air duct 311, so as to introduce the exhaust air of the cement mill into the fluidizing air main duct 321 and the lifting air duct 311 respectively. The first butterfly valve 334... A third valve 333 is installed on the pipeline between the three-way connector 332 and the lifting duct 311 to regulate the tail exhaust air entering the lifting duct 311; a second butterfly valve 334 is installed on the pipeline between the three-way connector 332 and the fluidizing air main pipe 321 to regulate the tail exhaust air entering the fluidizing air main pipe 321. Specifically, one end of the tail exhaust duct 331 is connected to the exhaust pipe of the cement mill as the air inlet, and the other end is connected to the inlet end of the three-way connector 332 to lead the tail exhaust air out of the exhaust pipe of the cement mill. The two outlet ends of the three-way connector 332 are respectively connected to the air inlet end of the lifting duct 311 and the air inlet end of the fluidizing air main pipe 321 through pipelines, thereby realizing the diversion of the tail exhaust air into the first tail exhaust air and the second tail exhaust air. A first butterfly valve 333 is installed on the pipeline from the three-way connector 332 to the lifting duct 311, and a second butterfly valve 334 is installed on the pipeline from the three-way connector 332 to the fluidizing air main 321. By adjusting the opening degree of the first butterfly valve 333 and the second butterfly valve 334, the air pressure of the first exhaust air entering the lifting duct 311 and the air pressure of the second exhaust air entering the fluidizing air main 321 can be precisely controlled, keeping them both within a predetermined range of 1200Pa to 1800Pa. The beneficial effect is that the exhaust air is naturally divided into two paths by the three-way connector 332, and the two independent butterfly valves enable precise and independent adjustment of the air pressure of the two paths. This ensures that the optimal air supply parameters required by the front and rear air chambers are maintained, and the distribution ratio of the exhaust air in each path can be flexibly adjusted according to the fluctuation of the raw material moisture content, ensuring that the device achieves the optimal dehydration effect under different operating conditions.

[0026] Secondly, this application provides a method for reducing cement moisture content, which is based on the device 10 of the first aspect that utilizes exhaust air to reduce cement moisture content, and includes the following steps: S1, introduces exhaust air and splits it into first exhaust air and second exhaust air; S2, which combines the first exhaust air and the lifting air into the first mixed air, and the second exhaust air and the fluidizing air into the second mixed air; S3, the first mixing air and the second mixing air are introduced into the conveying component 20 to reduce the moisture content of the cement during the conveying process.

[0027] In this invention, step S1 includes: S101, the exhaust air discharged from the cement mill is led out through the exhaust duct 331; S102, the exhaust air is split into the first exhaust air and the second exhaust air through the tee connector 332; Specifically, a diversion air intake is opened on the main exhaust duct at the tail of the cement mill, and one end of the tail exhaust duct 331 is sealed and connected to this air intake. The other end of the tail exhaust duct 331 is connected to the inlet end of a three-way connector 332, through which the exhaust air is split into two paths within the duct, serving as the first and second tail exhaust air respectively. The advantages are: air is directly drawn from the main exhaust duct at the tail of the mill, the air intake location is after the dust removal equipment, the air quality is clean and the air temperature is stable, and it can be directly introduced into the conveying chute 21 without additional purification treatment, simplifying the system structure and reducing modification costs.

[0028] In this invention, step S2 includes: S201, the first tail exhaust air is controlled by the first butterfly valve 333 to enter the lifting air duct 311 at the first predetermined air pressure, and is combined with the lifting air output by the first fan 312 to form the first mixed air; S202, the second tail exhaust air is controlled by the second butterfly valve 334 to enter the fluidizing air main pipe 321 at the second predetermined air pressure, and is combined with the fluidizing air output by the second fan 322 to form the second mixed air; Specifically, the first exhaust air, after its pressure is regulated by the first butterfly valve 333, enters the lifting duct 311, where it mixes with the ambient temperature lifting air blown in by the existing 4kW inclined slot fan (i.e., the first fan 312) to form a first mixed air with heat. The second exhaust air, after its pressure is regulated by the second butterfly valve 334, enters the fluidizing air main duct 321, where it mixes with the ambient temperature fluidizing air blown in by the other existing 4kW inclined slot fan (i.e., the second fan 322) to form a second mixed air with heat. The beneficial effects are: the exhaust air and the original fan-supplied air are pre-mixed in the duct, making the temperature, pressure, and velocity distribution of the hot air entering the air chamber more uniform, avoiding the direct impact of the high-temperature exhaust air on the permeable layer 22, which could cause local overheating or damage. At the same time, the pushing force of the original fan compensates for the pressure drop loss of the exhaust air during long-distance transport, ensuring the stable and reliable operation of the air supply system.

[0029] In this invention, both the first predetermined air pressure and the second predetermined air pressure are 1200Pa to 1800Pa. Specifically, the tail exhaust air pressure entering the lifting air duct 311 and the fluidizing air duct 321 is independently adjusted by the first butterfly valve 333 and the second butterfly valve 334, respectively, so that the air pressure of both tail exhaust air paths is maintained within the working range of 1200Pa to 1800Pa. This air pressure range is a preferred parameter range determined by combining the negative pressure inside the large bag dust collector in the cement grinding system, the negative pressure of the finished product chute dust collection, and the resistance characteristics of the permeable layer 22. Its beneficial effects are: when the air pressure is below 1200Pa, the ability of hot air to penetrate the cement material layer is insufficient, the material cannot be fully suspended, and water vapor is difficult to be effectively carried out; when the air pressure is above 1800Pa, excessive air pressure may cause excessive wear or even damage to the permeable layer 22, while increasing the power consumption of the fan. By controlling the air pressure within the preferred range of 1200Pa to 1800Pa, it is possible to ensure that the hot air can fully penetrate the material layer and effectively suspend the material, while also ensuring the service life of the permeable layer 22 and the economical operation of the system, so that the moisture reduction effect reaches the best balance point.

[0030] In this invention, step S3 includes: S301, the first mixed air first enters the front air chamber along the lifting air duct 311, and then passes through the permeable layer 22 to enter the material conveying chamber, so that the cement is suspended and flowed at the feed end of the conveying chute 21 and is heated and dehydrated. S302, the second mixing air first enters each fluidizing air branch pipe 323 along the fluidizing air main pipe 321, then enters the rear air chamber, and then passes through the permeable layer 22 to enter the material conveying chamber, so that the cement is fluidized and heated and dehydrated in the conveying chute 21. Specifically, the first mixed air is guided to the front air chamber of the conveying chute 21 via the lifting air duct 311, and then evenly passes through the permeable layer 22 into the material conveying chamber above. Compared to before the modification, the hot air, with a larger air volume, higher air pressure, and a temperature of 60-90℃, blows up the cement particles at the front end of the conveying chute 21, causing them to float and flow, breaking up the material accumulation layer. At the same time, the hot air penetrates the material layer and heats the free water on the surface of the cement particles, accelerating moisture vaporization. The second mixed air is distributed to each fluidizing air branch duct 323 via the fluidizing air main duct 321, and then evenly enters the rear air chamber, passing through the permeable layer 22 into the material conveying chamber. This hot air keeps the cement in a stable fluidized state within the conveying chute 21 and continuously heats the material, further evaporating moisture. The vaporized water vapor is quickly extracted under the negative pressure environment of the bag filter and the finished product chute, achieving a reduction in the moisture content of the finished cement. Its beneficial effects are as follows: the first mixing air achieves a synergistic effect of "suspension disturbance + hot air drying" at the feeding end, eliminating the closed environment of water vapor inside the material layer; the second mixing air maintains a stable working condition of "fluidized conveying + continuous drying" in the later section, and the dual negative pressure environment ensures that the evaporated water vapor is discharged in time and does not accumulate. The two air paths form an optimized dewatering process of "first strong blowing to disperse the pile, then stable flow to extend drying", which reduces the free moisture of the finished cement by 0.15% to 0.30%.

[0031] Example 1: Working process of device 10 for reducing cement moisture using exhaust ventilation 1. The exhaust air discharged from the cement mill is led out through the exhaust duct 331 and enters the inlet end of the tee connector 332; 2. The exhaust air is split into the first exhaust air and the second exhaust air via the 332 three-way connector; 3. The first exhaust air enters the lifting duct 311 after being regulated by the first butterfly valve 333; the lifting air output by the first fan 312 enters the lifting duct 311, and the first exhaust air and the lifting air are combined into the first mixed air in the lifting duct 311; at the same time, the second exhaust air enters the fluidizing air main duct 321 after being regulated by the second butterfly valve 334; the fluidizing air output by the second fan 322 enters the fluidizing air main duct 321, and the second exhaust air and the fluidizing air are combined into the second mixed air in the fluidizing air main duct 321. 4. The first mixed air enters the front air chamber along the lifting air duct 311, passes through the permeable layer 22 and enters the material conveying chamber; the second mixed air enters each fluidizing air branch duct 323 along the fluidizing air main duct 321, and then enters the rear air chamber through each fluidizing air branch duct 323, passes through the permeable layer 22 and enters the material conveying chamber. 5. Cement enters the feed end of the conveying chute 21 from the discharge port of the cement mill. At the feed end of the conveying chute 21, it comes into contact with the first mixing air and is in a suspended flow state. The cement moves along the rear section of the conveying chute 21 and comes into contact with the second mixing air at the rear section of the conveying chute 21, where it is in a fluidized state. Finally, it enters the storage tank from the discharge end of the conveying chute 21.

[0032] Example 2: Experiment on the reduction of cement moisture under different air source conditions I. Experimental Conditions The same cement mill and the same conveying chute 21 remained unchanged during the experiment, as did the inclination angle of the conveying chute 21 and the material and specifications of the permeable layer 22. The first fan 312 and the second fan 322 were both existing 4kW chute fans, and their airflow and pressure remained constant throughout the experiment. The exhaust air was taken from the cement mill's exhaust duct, with a temperature of 60–90℃. The first butterfly valve 333 and the second butterfly valve 334 adjusted the air pressure of the first and second exhaust air to 1500Pa, respectively. The cement type, grinding conditions, and conveying rate remained stable throughout the experiment.

[0033] Among them, the main dust collection air refers to the exhaust air drawn from the exhaust duct of the main dust collector of the cement mill; the finished product chute air refers to the exhaust air drawn from the dust collection air duct of the finished product conveying chute.

[0034] II. Data Acquisition Methods Under each condition, after the conveying system stabilizes, samples are taken every 10 minutes at the discharge end of the conveying chute 21 for one hour. The samples are then mixed and reduced to obtain a composite sample. The free moisture content in the composite sample is determined using the drying method: a certain amount of sample is weighed and dried at 105℃ to constant weight, and the moisture content is calculated. Sampling and testing are performed using the same method under four conditions: before modification, with the main dust collector running alone, with the finished product chute running alone, and with both air paths shared. Eleven corresponding sample data are obtained for each condition.

[0035] III. Setting up different air source conditions (1) Before the modification: the tail exhaust assembly 33 is closed, the lifting air output by the first fan 312 enters the lifting air duct 311, the fluidizing air output by the second fan 322 enters the fluidizing air main duct 321, and the cement is transported to the storage warehouse via the conveying chute 21.

[0036] (2) Open the main dust collection air separately: Open the valve between the main dust collection air duct and the tail exhaust air duct 331, and close the valve between the finished product inclined chute air duct and the tail exhaust air duct 331. The main dust collection air enters the three-way joint 332 through the tail exhaust air duct 331 and is divided into the first tail exhaust air and the second tail exhaust air; the first tail exhaust air and the lifting air output by the first fan 312 are combined into the first mixed air in the lifting air duct 311, and the second tail exhaust air and the fluidizing air output by the second fan 322 are combined into the second mixed air in the fluidizing air main duct 321; the first mixed air enters the material conveying chamber through the front air chamber and the permeable layer 22, and the second mixed air enters the material conveying chamber through each fluidizing air branch pipe 323, the rear air chamber, and the permeable layer 22. Cement is conveyed to the storage warehouse through the conveying inclined chute 21.

[0037] (3) Separately open the finished product inclined chute air: Open the valve between the finished product inclined chute air pipe and the tail exhaust air pipe 331, and close the valve between the main dust collection air pipe and the tail exhaust air pipe 331. The finished product inclined chute air enters the three-way connector 332 through the tail exhaust air pipe 331 and is divided into the first tail exhaust air and the second tail exhaust air; the subsequent merging and conveying process is the same as (2).

[0038] (4) Sharing two air paths: Simultaneously open the valves between the main dust collection air duct and the finished product inclined trough air duct and the tail exhaust air duct 331. The main dust collection air and the finished product inclined trough air merge in the tail exhaust air duct 331 and then enter the three-way connector 332, where they are split into the first tail exhaust air and the second tail exhaust air; the subsequent merging and conveying process is the same as in (2). IV. Test Results Table 1 shows the cement moisture content test results under different air source conditions. Table 1 V. Data Analysis The average values ​​calculated from Table 1 show that the average cement moisture content before the renovation was 0.85%; after sharing both airflow paths, the average cement moisture content was 0.68%, a decrease of 0.16 percentage points compared to before the renovation, with an average reduction rate of 19.1%. When the main dust collection airflow was used alone, the average cement moisture content was 0.74%, a decrease of 0.10 percentage points compared to before the renovation, with an average reduction rate of 12.4%. When the finished product chute airflow was used alone, the average cement moisture content was 0.78%, a decrease of 0.07 percentage points compared to before the renovation, with an average reduction rate of 8.0%; the average moisture content of the shared airflow paths was 0.06 percentage points lower than that of the main dust collection airflow used alone, and 0.09 percentage points lower than that of the finished product chute airflow used alone.

[0039] A comparison of the 11 sets of data in Table 1 shows that the cement moisture content in each group under all three modification conditions was lower than before the modification. Under the condition of sharing two airflow routes, 9 out of the 11 sets showed a reduction of at least 0.10 percentage points compared to before the modification, with groups 8 and 9 showing reductions of 0.07 and 0.04 percentage points respectively. Under the condition of operating the main dust collection airflow alone, the reduction in the 11 sets of data ranged from 0.01 to 0.21 percentage points compared to before the modification, with most concentrated between 0.05 and 0.21 percentage points. Under the condition of operating the finished product inclined duct airflow alone, the reduction in the 11 sets of data ranged from 0.02 to 0.17 percentage points compared to before the modification, with most concentrated between 0.02 and 0.11 percentage points.

[0040] The above results indicate that when the main dust collection air and the finished product chute air are introduced together, the reduction in cement moisture content is greater than when either air is introduced alone, suggesting that the drying effect of using both air sources is more significant.

[0041] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope of this application is indicated by the claims.

[0042] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The above embodiments of this application do not constitute a limitation on the scope of protection of this application.

Claims

1. A device for reducing the moisture content of cement using exhaust ventilation, characterized in that, The system includes a conveying component and an air supply component. The inlet end of the conveying component is connected to the outlet of the cement mill, and the outlet end is connected to the storage tank to convey cement from the cement mill to the storage tank. The air supply component includes a lifting air assembly, a fluidizing air assembly, and a tail exhaust air assembly. The fluidizing air assembly is connected to the conveying component and is used to introduce fluidizing air into the conveying component to fluidize the cement inside the conveying component. The lifting air assembly is connected to the inlet end of the conveying component and is used to introduce lifting air into the inlet end of the conveying component to suspend and flow the cement. The inlet end of the tail exhaust air assembly is connected to the exhaust pipe of the cement mill to introduce the tail exhaust air of the cement mill. The two outlet ends are respectively connected to the fluidizing air assembly and the lifting air assembly, so that the tail exhaust air is combined with the fluidizing air generated by the fluidizing air assembly and the lifting air generated by the lifting air assembly and then introduced into the conveying component to reduce the moisture content of the cement during the conveying process.

2. The device for reducing cement moisture using exhaust air according to claim 1, characterized in that, The conveying component includes a conveying chute, a permeable layer, and a partition. The permeable layer is disposed within the conveying chute to divide it into an upper material conveying chamber and a lower air chamber. The partition is disposed within the air chamber to divide it into a front air chamber and a rear air chamber along the material conveying direction. The front air chamber is located at the feed end of the conveying chute, and the rear air chamber is located behind the front air chamber and extends along the conveying direction of the conveying chute to the discharge end. The front air chamber is connected to the lifting air assembly to introduce a first mixed air, which combines lifting air and exhaust air, and allows the first mixed air to enter the material conveying chamber through the permeable layer, causing the cement to suspend and flow at the feed end of the conveying chute. The rear air chamber is connected to the fluidizing air assembly to introduce a second mixed air, which combines fluidizing air and exhaust air, and allows the second mixed air to enter the material conveying chamber through the permeable layer, causing the cement to fluidize within the conveying chute.

3. The device for reducing cement moisture using exhaust air according to claim 2, characterized in that, The lifting air assembly includes a lifting air duct and a first fan. The two air inlets of the lifting air duct are respectively connected to the first fan and the tail exhaust assembly. The air outlet of the lifting air duct is connected to the front air chamber so as to uniformly introduce the first mixed air into the front air chamber, so that the cement is suspended and flows at the feed end of the conveying chute.

4. The device for reducing cement moisture using exhaust air according to claim 3, characterized in that, The fluidizing air assembly includes a main fluidizing air pipe, a second fan, and at least two branch fluidizing air pipes. The main fluidizing air pipe is located below the conveying chute and is arranged along the conveying direction of the conveying chute. The two air inlets of the main fluidizing air pipe are respectively connected to the second fan and the tail exhaust assembly. Each branch fluidizing air pipe is arranged at intervals along the conveying direction of the conveying chute, with one end connected to the main fluidizing air pipe and the other end connected to the rear air chamber, so as to uniformly introduce the second mixing air into the rear air chamber, so that the cement is fluidized in the conveying chute.

5. The device for reducing cement moisture using exhaust air according to claim 4, characterized in that, The exhaust assembly includes an exhaust duct, a tee connector, a first butterfly valve, and a second butterfly valve. One end of the exhaust duct is connected to the exhaust pipe of the cement mill, and the other end is connected to the inlet end of the tee connector. The two outlet ends of the tee connector are respectively connected to the inlet end of the fluidized air main pipe and the inlet end of the lifting air pipe, so as to introduce the exhaust air of the cement mill into the fluidized air main pipe and the lifting air pipe respectively. The first butterfly valve is set on the pipeline between the tee connector and the lifting air pipe to regulate the exhaust air entering the lifting air pipe. The second butterfly valve is set on the pipeline between the tee connector and the fluidized air main pipe to regulate the exhaust air entering the fluidized air main pipe.

6. A method for reducing cement moisture content, the method being based on the apparatus for reducing cement moisture content using exhaust ventilation as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1, introduces exhaust air and splits it into first exhaust air and second exhaust air; S2, which combines the first exhaust air and the lifting air into the first mixed air, and the second exhaust air and the fluidizing air into the second mixed air; S3, the first and second mixing air are introduced into the conveying component to reduce the moisture content of the cement during the conveying process.

7. The method for reducing cement moisture according to claim 6, characterized in that, Step S1 includes: S101, the exhaust air discharged from the cement mill is led out through the exhaust duct; S102, the exhaust air is split into the first exhaust air and the second exhaust air through the tee joint.

8. A method for reducing the moisture content of cement according to claim 6, characterized in that, Step S2 includes: S201, the first tail exhaust air is controlled by the first butterfly valve to enter the lifting air duct at the first predetermined air pressure, and is combined with the lifting air output by the first fan to form the first mixed air; S202, the second tail exhaust air is controlled by the second butterfly valve to enter the fluidizing air main pipe at the second predetermined air pressure, and is combined with the fluidizing air output by the second fan to form the second mixed air.

9. A method for reducing cement moisture content according to claim 8, characterized in that, Both the first predetermined wind pressure and the second predetermined wind pressure are 1200Pa to 1800Pa.

10. A method for reducing the moisture content of cement according to claim 6, characterized in that, Step S3 includes: S301, the first mixed air enters the front air chamber along the lifting air duct, and then passes through the permeable layer into the material conveying chamber, so that the cement is suspended and flowed at the feed end of the conveying chute and is heated and dehydrated. S302, the second mixing air first enters each fluidizing air branch pipe along the main fluidizing air pipe, then enters the rear air chamber, and then passes through the permeable layer into the material conveying chamber, so that the cement is fluidized and heated and dehydrated in the conveying chute.

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