Kiln exhaust fan based on cement production
By installing a spray system in front of the kiln tail exhaust fan to cool and remove dust from the flue gas, the problem of the kiln tail exhaust fan operating at high temperatures is solved, costs are reduced, blade life is extended, and equipment stability is improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SINOMA GANSU CEMENT CO LTD
- Filing Date
- 2023-05-08
- Publication Date
- 2026-06-09
AI Technical Summary
Existing kiln tail exhaust fans operate under high-temperature flue gas, which leads to a decline in the mechanical properties of the blades, a shortened lifespan, and high costs.
A spray system is installed in front of the exhaust fan to cool and initially remove dust from the flue gas using high-pressure water flow, thereby reducing the flue gas temperature. The system also continuously washes the flue gas while the blades are in operation to prevent the accumulation of adhering substances.
The high-temperature resistance requirements of the exhaust fan motor have been reduced, costs have been lowered, and the service life and stability of the blades have been improved, reducing the burden on the motor.
Smart Images
Figure CN116538816B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of exhaust fan technology, and specifically to a kiln tail exhaust fan used in cement production. Background Technology
[0002] In the dry process cement production line, raw materials are fed into the kiln tail suspension preheater, where they undergo thorough heat exchange with the hot airflow inside the kiln, separating gaseous dust from solid particles. The resulting flue gas, with a temperature of 300-450 degrees Celsius, is discharged from the kiln tail preheater outlet after preheating, decomposition, and calcination. The flue gas is characterized by its large volume, high temperature, high concentration, and corrosive components such as acids, alkalis, and oxides. Furthermore, over 60% of the dust particles are smaller than 2.5 μm, resulting in high dust viscosity. After passing through the kiln tail exhaust fan, the flue gas must be further purified. The flue gas enters the corresponding spray cooling and dust removal device, as well as other purification devices for flue gas purification. Currently, the kiln tail exhaust fan only provides exhaust ventilation. After the kiln tail flue gas enters the kiln tail exhaust fan, due to the high temperature of the kiln tail flue gas, the power source (motor) of the kiln tail exhaust fan is required to have high temperature resistance, which leads to increased costs. In addition, the exhaust fan blades are in a high-temperature state when working and gradually cool down after shutdown. The alternating hot and cold process will increase the brittleness of the blades, which will reduce the mechanical properties of the blades and thus reduce their lifespan. Summary of the Invention
[0003] To address the shortcomings of existing technologies, this invention provides a kiln tail exhaust fan used in cement production. This device can cool the kiln tail gas to reduce its temperature, thereby reducing the high-temperature resistance requirements of the exhaust fan motor and thus lowering costs. At the same time, it can also keep the exhaust fan blades operating at a relatively low temperature, improving the service life of the blades.
[0004] A kiln tail exhaust fan for cement production includes a pipe, an exhaust fan, and a spray assembly. The left end of the pipe is the air inlet, and a through hole is opened in the bottom wall of the pipe. The bottom of the through hole is connected to an open box at the top. A water inlet pipe and a water outlet pipe are connected to the box. A filter screen is installed in the water outlet pipe. An inlet valve is installed in the water inlet pipe, and an outlet valve is installed in the water outlet pipe. A drain hole is opened in the bottom wall of the box, and a drain valve is installed at the drain hole. The spray assembly includes a water pump, a main pipe, and multiple branch pipes. One end of the main pipe is connected to the drain end of the water pump, and the other end of the main pipe is closed. The multiple branch pipes are arranged longitudinally, and the top of the branch pipes passes through the box and the through hole to enter the pipe. The top of the branch pipes is close to the top wall of the pipe. The bottom ends of the multiple branch pipes are all connected to the main pipe. The exhaust fan is installed on the right side of the branch pipes.
[0005] Preferably, the pipe includes a horizontal section, an arc section, and a vertical section, with the two ends of the arc section connected to the horizontal section and the vertical section, respectively. The exhaust fan includes an outer cylinder, an inner cylinder, a bottom annular plate, a top annular plate, a main shaft, a connecting rod, an external gear ring, a rotating shaft, a gear, a motor, multiple blades, and multiple nozzle assemblies.
[0006] The top and bottom of the outer cylinder are fixed to the top annular plate and the bottom annular plate, respectively. The top and bottom of the inner cylinder are rotatably sealed on the top annular plate and the bottom annular plate, respectively. The outer wall of the outer cylinder is fixed to the inner wall of the vertical section. A second water inlet pipe is connected to the outer cylinder and passes through the side wall of the vertical section.
[0007] The main shaft is located inside the inner cylinder, and multiple blades are fixed on the main shaft. The main shaft is connected to the inner wall of the inner cylinder through a connecting rod. An outer gear ring is fitted on the outer wall of the inner cylinder. A rotating shaft is rotatably mounted on the top annular plate. A gear is connected to the rotating shaft and meshes with the outer gear ring. A motor is fixed on the top wall of the top annular plate. The output shaft of the motor passes through the top annular plate and is rotatably and sealed to the top annular plate. The output shaft of the motor is connected to the rotating shaft. When the motor starts, it can drive the outer gear ring to rotate clockwise. The nozzle assembly corresponds to the blades one by one. The nozzle assembly includes a first nozzle and a second nozzle. Both the first nozzle and the second nozzle penetrate the inner cylinder. When the blade is located above the main shaft and in a vertical position, the first nozzle is located above the blade to the left, and the second nozzle is located directly above the blade. The first nozzle sprays water downwards to the right to the left wall of the blade, and the second nozzle sprays water vertically to the right wall of the blade.
[0008] The external gear ring is located on the upper or lower side of the nozzle assembly.
[0009] Preferably, the exhaust fan further includes a middle cylinder, the top and bottom of which are rotatably sealed on a top annular plate and a bottom annular plate, respectively. The middle cylinder is located between the outer cylinder and the inner cylinder, and a gear is located between the middle cylinder and the inner cylinder. The first nozzle and the second nozzle both penetrate the inner cylinder and the middle cylinder, and the outer gear ring and the gear are located on the upper side of the nozzle assembly.
[0010] Preferably, the connecting rods are provided as multiple rods, which are evenly distributed circumferentially around the axis of the main shaft.
[0011] Preferably, the top annular plate has multiple rotating shafts rotatably arranged, each shaft is connected to a gear, each gear meshes with an external gear ring, and the motor corresponds one-to-one with the rotating shaft.
[0012] Preferably, the multiple rotating shafts are evenly distributed circumferentially around the axis of the top annular plate.
[0013] Preferably, the branch pipe is arranged vertically.
[0014] Preferably, the water pump is a high-pressure water pump.
[0015] The beneficial effects of this invention are as follows: In this technical solution, a spray assembly is installed in front of the exhaust fan. In specific use, the inlet valve is opened, and cold water is continuously injected through the inlet pipe until the water level in the box is higher than the height of the outlet pipe. Then, the outlet valve is opened to keep the water level in the box always higher than the height of the outlet pipe. High-pressure water is pumped in by a water pump. The high-pressure water is discharged through the main pipe and branch pipe. The high-pressure water impacts the top wall of the pipe, forming water droplets that fall down. After the exhaust gas enters the pipe, it comes into contact with the falling water droplets, which cools it down and removes some dust. Then it enters the exhaust fan. The water droplets pick up dust and fall into the box. Some of the dust settles in the box, and the excess water is discharged through the outlet pipe. The fact that the water level in the box is always higher than the height of the outlet pipe can prevent the gas from being discharged from the box. In this way, the gas enters the exhaust fan after being cooled down and removed from some dust. This cools the kiln tail gas, reduces the temperature of the exhaust gas, and reduces the high temperature resistance requirements of the exhaust fan motor, thereby reducing costs. At the same time, it can also keep the exhaust fan blades at a relatively low temperature, improving the service life of the blades. Attached Figure Description
[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.
[0017] Figure 1 This is a front cross-sectional view of the present invention;
[0018] Figure 2 This is a top cross-sectional view of the exhaust fan in Example 2;
[0019] Figure 3 This is a top cross-sectional view of the exhaust fan in Example 3.
[0020] In the attached diagram, 1-pipe, 2-exhaust fan, 3-through hole, 4-box body, 5-inlet pipe one, 6-outlet pipe, 7-water pump, 8-main pipe, 9-branch pipe, 201-outer cylinder, 202-inner cylinder, 203-main shaft, 204-blade, 205-connecting rod, 206-external gear ring, 207-rotating shaft, 208-gear, 209-motor, 210-first nozzle, 211-second nozzle, 212-inlet pipe two, 213-middle cylinder. Detailed Implementation
[0021] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.
[0022] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.
[0023] Example 1
[0024] like Figure 1 As shown, this embodiment provides a kiln tail exhaust fan for cement production, including a pipe 1, an exhaust fan 2, and a spray assembly. The left end of the pipe 1 is the air inlet. A through hole 3 is opened in the bottom wall of the pipe 1. The bottom of the through hole 3 is connected to a box 4 with an open top. A water inlet pipe 5 and a water outlet pipe 6 are connected to the box 4. A water inlet valve is installed in the water inlet pipe 5, and a water outlet valve is installed in the water outlet pipe 6. A filter screen is installed in the water outlet pipe 6. A drain hole is opened in the bottom wall of the box 4, and a drain valve is installed at the drain hole. The spray assembly includes a water pump 7, a main pipe 8, and multiple branch pipes 9. One end of the main pipe 8 is connected to the drain end of the water pump 7, and the other end of the main pipe 8 is closed. The multiple branch pipes 9 are arranged longitudinally. The top of the branch pipes 9 passes through the box 4 and the through hole 3 and enters the pipe 1. The top of the branch pipes 9 is close to the top wall of the pipe 1. The bottom ends of the multiple branch pipes 9 are all connected to the main pipe 8. The exhaust fan 2 is installed on the right side of the branch pipes 9.
[0025] In this embodiment, the branch pipe 9 is vertically arranged. In this embodiment, the water pump 7 is a high-pressure water pump.
[0026] In this embodiment, a spray assembly is installed in front of the exhaust fan 2. During use, the inlet valve is opened, and cold water is continuously injected through the inlet pipe 5 until the water level in the housing 4 is higher than the height of the outlet pipe 6. Then, the outlet valve is opened, maintaining the water level in the housing 4 consistently higher than the height of the outlet pipe 6. High-pressure water is pumped in by the water pump 7, and the high-pressure water is discharged through the main pipe 8 and branch pipe 9. The high-pressure water impacts the top wall of pipe 1, forming water droplets that fall. After the exhaust gas enters pipe 1, it comes into contact with the falling water droplets for cooling and initial dust removal before entering the exhaust fan. Inside the chamber 2, water droplets, carrying dust, fall into the chamber 4, where the dust settles. Excess water is discharged through the outlet pipe 6. The water level in the chamber 4 is always higher than the height of the outlet pipe 6 to prevent gas from escaping from the chamber 4. Thus, after being cooled and initially dust-removed, the gas enters the exhaust fan 2, thereby cooling the kiln tail gas and reducing its temperature. This reduces the high-temperature resistance requirements of the exhaust fan 2 motor, thereby reducing costs. It also allows the exhaust fan 2 blades to operate at a relatively low temperature, improving their service life.
[0027] Example 2
[0028] This embodiment further defines the features of Embodiment 1. In this embodiment, the pipe 1 includes a horizontal section, an arc section, and a vertical section. The two ends of the arc section are connected to the horizontal section and the vertical section, respectively. The exhaust fan 2 includes an outer cylinder 201, an inner cylinder 202, a bottom annular plate, a top annular plate, a main shaft 203, a connecting rod 205, an external gear ring 206, a rotating shaft 207, a gear 208, a motor 209, multiple blades 204, and multiple nozzle assemblies.
[0029] The top and bottom ends of the outer cylinder 201 are fixed on the top annular plate and the bottom annular plate, respectively. The top and bottom ends of the inner cylinder 202 are rotatably sealed on the top annular plate and the bottom annular plate, respectively. The outer wall of the outer cylinder 201 is fixed on the inner wall of the vertical section. A second water inlet pipe 212 is connected to the outer cylinder 201. The second water inlet pipe 212 passes through the side wall of the vertical section.
[0030] The main shaft 203 is located inside the inner cylinder 202. Multiple blades 204 are fixed on the main shaft 203. The main shaft 203 is connected to the inner wall of the inner cylinder 202 via a connecting rod 205. An external gear ring 206 is fitted onto the outer wall of the inner cylinder 202. A rotating shaft 207 is rotatably mounted on the top annular plate. A gear 208 is connected to the rotating shaft 207 and meshes with the external gear ring 206. A motor 209 is fixed to the top wall of the top annular plate. The output shaft of the motor 209 passes through the top annular plate and is rotatably and sealed to the top annular plate. The output shaft of the motor 209 is connected to the rotating shaft 207. When the motor 209 starts, it can drive the external gear ring 206 to rotate clockwise. The nozzle assembly corresponds one-to-one with the blade 204. The nozzle assembly includes a first nozzle 210 and a second nozzle 211. Both the first nozzle 210 and the second nozzle 211 penetrate the inner cylinder 202. When the blade 204 is located above the main shaft 203 and is in a vertical position, the first nozzle 210 is located to the upper left of the blade 204, and the second nozzle 211 is located directly above the blade 204. The first nozzle 210 sprays water to the lower right to the left wall of the blade 204, and the second nozzle 211 sprays water vertically to the right wall of the blade 204.
[0031] The external gear ring 206 is located on the upper or lower side of the nozzle assembly.
[0032] The exhaust gas temperature is reduced to some extent after being cooled by the spray assembly, but it is still relatively high. The blades of exhaust fan 2 are in a high-temperature state during operation and gradually cool down after shutdown. The alternating hot and cold process also increases the brittleness of the blades. In addition, due to the high adhesiveness of the exhaust gas itself, particles that do not enter the housing 4 after being sprayed with water droplets will pass through exhaust fan 2 and easily adhere to the blades of exhaust fan 2. After drying on the blades of exhaust fan 2, the weight of the blades of exhaust fan 2 will continuously increase. After long-term use, the blades of exhaust fan 2 may break. In addition, as the weight of the blades increases, the load on motor 209 will continuously increase. If the load exceeds the bearing capacity of motor 209, it will also damage motor 209. Thus, the lifespan of exhaust fan 2 cannot be effectively extended.
[0033] In this embodiment, the exhaust fan 2 includes an outer cylinder 201, an inner cylinder 202, a bottom annular plate, a top annular plate, a main shaft 203, a connecting rod 205, an outer gear ring 206, a rotating shaft 207, a gear 208, a motor 209, multiple blades 204, and multiple nozzle assemblies. During operation, the motor 209 drives the rotating shaft 207 to rotate, which in turn drives the gear 208 to rotate, which in turn drives the outer gear ring 206 to rotate clockwise. The rotation of the outer gear ring 206 drives the main shaft 203 to rotate via the connecting rod 205. The rotation of the main shaft 203 then drives the blades 204 to rotate, thus achieving the exhaust function. The motor 209 is mounted on the top annular plate and is not located inside the inner cylinder 202. Compared to traditional exhaust fans where the motor 209 is located inside the inner cylinder 202, in this embodiment, the motor 209 does not occupy the internal exhaust channel of the inner cylinder 202, thereby improving the exhaust capacity of the exhaust fan.
[0034] During the exhaust process of the exhaust fan 2, water is injected into the cavity between the outer cylinder 201 and the inner cylinder 202 through the water inlet pipe 212. After the water fills the cavity between the outer cylinder 201 and the inner cylinder 202, it is discharged through the first nozzle 210 and the second nozzle 211. The first nozzle 210 and the second nozzle 211 respectively wash the two side walls of the blade 204 to ensure that the blade 204 always operates at a lower temperature, thereby reducing the problem of blade 204 damage caused by increased brittleness. In addition, the water flow constantly washes the blade 204, which can prevent particulate matter from adhering to the blade 204, increasing the weight of the blade 204, and thus preventing the blade 204 from breaking. Since the weight of the blade 204 does not increase, it does not add extra burden to the motor 209. The motor 209 always operates within the set load, thereby reducing the problem of motor 209 damage.
[0035] The direction of the water jet from the first nozzle 210 and the second nozzle 211 always rotates along with the rotation of the blade 204, and the setting of the direction of the water jet does not increase the load on the rotation of the blade 204.
[0036] Figure 2 The external gear ring 206 shown is located on the lower side of the nozzle assembly.
[0037] In this embodiment, the connecting rod 205 is configured as multiple rods, which are evenly distributed circumferentially around the axis of the main shaft 203, thereby further improving the stability of the connection.
[0038] In this embodiment, multiple rotating shafts 207 are rotatably mounted on the top annular plate. Each shaft 207 is connected to a gear 208, and each gear 208 meshes with an external gear ring 206. A motor 209 corresponds one-to-one with each rotating shaft 207. In this embodiment, the multiple rotating shafts 207 are evenly distributed circumferentially around the axis of the top annular plate. The use of multiple motors 209 for driving ensures sufficient power output and operational stability.
[0039] Example 3
[0040] This embodiment further defines the features of embodiment 2. In this embodiment, the exhaust fan 2 also includes a middle cylinder 213. The top and bottom ends of the middle cylinder 213 are rotatably sealed on the top annular plate and the bottom annular plate, respectively. The middle cylinder 213 is located between the outer cylinder 201 and the inner cylinder 202. The gear 208 is located between the middle cylinder 213 and the inner cylinder 202. The first nozzle 210 and the second nozzle 211 both penetrate the inner cylinder 202 and the middle cylinder 213. The outer gear ring 206 and the gear 208 are located on the upper side of the nozzle assembly.
[0041] In Embodiment 2, the cavity between the inner cylinder 202 and the outer cylinder 201 needs to be filled with water. This results in greater resistance to the movement of the gear 208 in the water, leading to significant energy waste. In this embodiment, a middle cylinder 213 is provided. During operation, the gear 208 is located between the middle cylinder 213 and the inner cylinder 202. Water flows through the cavity formed between the middle cylinder 213 and the outer cylinder 201. During operation, the gear 208 does not need to rotate in the water, thereby reducing the resistance to the rotation of the gear 208 and thus reducing energy consumption.
[0042] Since the nozzle assembly needs to rotate, in this embodiment, the gear 208 and the external gear ring 206 are located on the upper side of the nozzle assembly, so as not to obstruct the movement of the nozzle assembly.
[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.
Claims
1. A kiln tail exhaust fan used in cement production, characterized in that, The system includes a pipe (1), an exhaust fan (2), and a spray assembly. The left end of the pipe (1) is the air inlet. A through hole (3) is opened on the bottom wall of the pipe (1). The bottom of the through hole (3) is connected to a box (4) with an open top. A water inlet pipe (5) and a water outlet pipe (6) are connected to the box (4). A water inlet valve is installed in the water inlet pipe (5), and a water outlet valve is installed in the water outlet pipe (6). A filter screen is installed in the water outlet pipe (6). A drain hole is opened on the bottom wall of the box (4), and a drain valve is installed at the drain hole. The spray assembly includes... Includes a water pump (7), a main pipe (8) and multiple branch pipes (9). One end of the main pipe (8) is connected to the drainage end of the water pump (7), and the other end of the main pipe (8) is closed. Multiple branch pipes (9) are arranged longitudinally. The top of the branch pipe (9) passes through the box (4) and the through hole (3) and enters the pipe (1). The top of the branch pipe (9) is close to the top wall of the pipe (1). The bottom of the multiple branch pipes (9) is connected to the main pipe (8). The exhaust fan (2) is installed on the right side of the branch pipe (9). The pipe (1) includes a horizontal section, an arc section and a vertical section. The two ends of the arc section are connected to the horizontal section and the vertical section respectively. The exhaust fan (2) includes an outer cylinder (201), an inner cylinder (202), a bottom annular plate, a top annular plate, a main shaft (203), a connecting rod (205), an external gear ring (206), a rotating shaft (207), a gear (208), a motor (209), multiple blades (204) and multiple nozzle assemblies. The top and bottom ends of the outer cylinder (201) are fixed on the top annular plate and the bottom annular plate respectively. The top and bottom ends of the inner cylinder (202) are rotatably sealed on the top annular plate and the bottom annular plate respectively. The outer wall of the outer cylinder (201) is fixed on the inner wall of the vertical section. The outer cylinder (201) is connected to the second water inlet pipe (212), which passes through the side wall of the vertical section. The main shaft (203) is located inside the inner cylinder (202), and multiple blades (204) are fixed on the main shaft (203). The main shaft (203) is connected to the inner wall of the inner cylinder (202) through a connecting rod (205). An external gear ring (206) is fitted on the outer wall of the inner cylinder (202). A rotating shaft (207) is rotatably mounted on the top annular plate. A gear (208) is connected to the rotating shaft (207). The gear (208) meshes with the external gear ring (206). A motor (209) is fixed on the top wall of the top annular plate. The output shaft of the motor (209) passes through the top annular plate. The output shaft of the motor (209) is rotatably and sealedly connected to the top annular plate. The output shaft of the motor (209) is connected to the rotating shaft (207). Then, the motor (209) starts and can drive the external gear ring (206) to rotate clockwise. The nozzle assembly corresponds one-to-one with the blade (204). The nozzle assembly includes a first nozzle (210) and a second nozzle (211). Both the first nozzle (210) and the second nozzle (211) pass through the inner cylinder (202). When the blade (204) is located above the main shaft (203) and in a vertical state, the first nozzle (210) is located to the upper left of the blade (204), and the second nozzle (211) is located directly above the blade (204). The first nozzle (210) sprays water to the lower right to the left wall of the blade (204), and the second nozzle (211) sprays water vertically to the right wall of the blade (204). The external gear ring (206) is located on the upper or lower side of the nozzle assembly; The exhaust fan (2) also includes a middle cylinder (213), the top and bottom ends of which are rotatably sealed on the top annular plate and the bottom annular plate, respectively. The middle cylinder (213) is located between the outer cylinder (201) and the inner cylinder (202). The gear (208) is located between the middle cylinder (213) and the inner cylinder (202). The first nozzle (210) and the second nozzle (211) both penetrate the inner cylinder (202) and the middle cylinder (213). The outer gear ring (206) and the gear (208) are located on the upper side of the nozzle assembly.
2. The kiln tail exhaust fan for cement production according to claim 1, characterized in that, The connecting rod (205) is configured as multiple rods, which are evenly distributed circumferentially around the axis of the main shaft (203).
3. The kiln tail exhaust fan for cement production according to claim 1, characterized in that, Multiple rotating shafts (207) are rotatably arranged on the top annular plate. Each rotating shaft (207) is connected to a gear (208). Each gear (208) meshes with an external gear ring (206). The motor (209) corresponds to each rotating shaft (207).
4. A kiln tail exhaust fan for cement production according to claim 3, characterized in that, Multiple rotating shafts (207) are evenly distributed circumferentially around the axis of the top annular plate.
5. A kiln tail exhaust fan for cement production according to claim 1, characterized in that, The branch pipe (9) is set vertically.
6. A kiln tail exhaust fan for cement production according to claim 1, characterized in that, The water pump (7) is a high-pressure water pump.