Tail gas induced draft fan and calcining furnace system

Abstract

The utility model relates to the field of tail gas treatment of combustion equipment, in particular to a tail gas induced draft fan and a calcining furnace system.The tail gas induced draft fan comprises an induced draft module and a transmission module, the induced draft module comprises an air inlet (1), a machine shell (2) and an air outlet (7), and the machine shell (2) is connected with the air inlet and internally provided with a fan impeller; the transmission module comprises a bearing box (3) and a main shaft which is rotatably installed on the bearing box and is in transmission connection with the fan impeller, a heat dissipation impeller (10) located between the machine shell and the bearing box is arranged on the main shaft, and a cooling device is further arranged in the bearing box. In the working process, the heat dissipation impeller rotates along with rotation of the main shaft to form airflow blowing to the bearing box, and therefore forced heat dissipation is conducted on the bearing box. Through cooperative work of the heat dissipation impeller and the cooling device, the temperature of the bearing box can be reduced to the working temperature interval of the bearing box, and the tail gas induced draft fan can work stably.

Description

Technical Field

[0001] The utility model relates to the field of exhaust gas treatment of combustion equipment, and particularly to an exhaust gas induced draft fan. On this basis, the utility model also relates to a calcination furnace system including the exhaust gas induced draft fan. Background Art

[0002] In industrial production, various industrial furnaces are applied to the heating and calcination processes of materials. According to the requirements of the materials and the processes, when heating and calcining some materials, the gas in the furnace needs to be replaced, or the materials in the furnace will generate gas during the process. In these cases, the industrial furnace will discharge a large amount of exhaust gas, and the discharged exhaust gas is usually high-temperature gas. If it is not discharged quickly under pressure, it will cause heat accumulation in the industrial furnace, resulting in overheating and damage to the industrial furnace and even safety accidents. Therefore, it is necessary to install an exhaust gas induced draft fan on the industrial furnace to pressurize the exhaust gas and guide it to be discharged quickly to ensure the normal operation of the industrial furnace.

[0003] The exhaust gas induced draft fan pressurizes the exhaust gas generated by the industrial furnace by driving the impeller arranged therein, so as to quickly discharge the exhaust gas. When transporting high-temperature exhaust gas, the heat of the high-temperature exhaust gas will be transmitted to each component of the exhaust gas fan through the fan impeller and the drive shaft in the induced draft fan. When the temperature of the high-temperature exhaust gas is too high, each component of the exhaust gas fan will overheat and cannot work normally, which will further lead to failures of the industrial furnace. Therefore, an exhaust gas induced draft fan that can dissipate heat by itself to ensure long-term operation and discharge high-temperature exhaust gas is needed.

[0004] Chinese Utility Model Patent CN 204164006 U provides an exhaust gas induced draft fan, which cools the intermediate shaft by arranging a cooling device using coolant on the intermediate shaft, so as to reduce the heat conducted from the intermediate shaft to other components of the exhaust gas fan. However, in actual use, only cooling the intermediate shaft still cannot cope with high-temperature working conditions. Although its technical solution reduces the heat transmitted from the intermediate shaft to each component through heat conduction, it does not reduce the heat transmitted by other heat transfer methods, nor directly dissipates heat from each component. Therefore, an exhaust gas induced draft fan that can directly dissipate heat from each of its components, so as to work for a long time under high-temperature working conditions and discharge high-temperature exhaust gas is needed. Summary of the Utility Model

[0005] The purpose of the utility model is to overcome the problem in the existing exhaust gas induced draft fan that the components cannot be directly cooled, resulting in the temperature of each component exceeding its working temperature and the exhaust gas induced draft fan cannot work for a long time.

[0006] To solve the above problems, in a first aspect, the present utility model provides an exhaust gas induced draft fan, which includes an induced draft module and a transmission module. The induced draft module includes an air inlet, a casing connected to the air inlet and having a fan impeller disposed therein, and an air outlet. The transmission module includes a bearing housing and a main shaft rotatably mounted to the bearing housing and drivingly connected to the fan impeller. A cooling impeller is provided on the main shaft between the casing and the bearing housing. The cooling impeller is configured to rotate with the main shaft and blow cooling air towards the bearing housing. A cooling device is also provided in the bearing housing.

[0007] Preferably, the cooling impeller is a semi-open impeller coaxially fixed to the main shaft.

[0008] Preferably, the projected area of the cooling impeller in the axial direction of the main shaft is larger than the projected area of the bearing housing in the axial direction of the main shaft.

[0009] Preferably, a lubrication device for lubricating the bearings provided therein is also provided in the bearing housing.

[0010] Preferably, the main shaft extends into the inner cavity of the casing and is drivingly connected to the fan impeller. A seal is provided at the position where the main shaft passes through the casing.

[0011] Preferably, the casing is a volute casing, and a spiral air duct centered on the fan impeller is provided therein. The air inlet and the air outlet are connected to this duct.

[0012] Preferably, a motor is provided at one end of the bearing housing away from the induced draft module. The main shaft extends through the bearing housing and is connected to the motor through a coupling.

[0013] Preferably, the casing, the bearing housing, and the motor are installed on the fan base at different heights so that the main shaft can be horizontally placed.

[0014] Preferably, the fan base is installed on the mounting base by bolts, and a shock pad surrounding the bolts is provided between the fan base and the mounting base.

[0015] In a second aspect, the present utility model also provides a calcining furnace system, which includes the above-mentioned exhaust gas induced draft fan.

[0016] When the exhaust draft fan is working, the main shaft can be driven to rotate, thereby driving the fan impeller connected to the main shaft to rotate, forming a negative pressure at the air inlet, and quickly discharging the exhaust gas from the air outlet through the air duct formed by the casing. The bearing box arranged in the middle section of the main shaft supports the main shaft and plays a role in positioning the main shaft when the main shaft rotates. The heat dissipation impeller installed between the casing and the bearing box is driven to rotate as the main shaft rotates, thereby forming an airflow blowing toward the bearing box along the axial direction of the main shaft, forcing the bearing box to dissipate heat. By forcing the bearing box to dissipate heat through the airflow generated by the heat dissipation impeller in the above technical solution, the temperature of the bearing in the bearing box can be reduced to the required operating temperature range, and can work in coordination with the cooling device in the bearing box, thereby ensuring that the exhaust draft fan can work stably for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a front view structural schematic diagram of an embodiment of the utility model;

[0019] Figure 2 It is a side view structural schematic diagram of an embodiment of the utility model;

[0020] Figure 3 It is a front view structural diagram of a main shaft and its upper components in one embodiment of the utility model;

[0021] Figure 4 It is a side view structural schematic diagram of a main shaft and its upper components in one embodiment of the utility model.

[0022] Description of Reference Numerals

[0023] 1. Air inlet; 2. Casing; 3. Bearing box; 4. Coupling; 5. Motor; 6. Fan base; 7. Air outlet; 8. Shock-absorbing pad; 9. Mounting base; 10. Cooling impeller. DETAILED DESCRIPTION

[0024] In the present utility model, unless otherwise stated, directional words such as "upper, lower, inside, outside" contained in a term merely represent the orientation of the term in normal use, or are common names understood by those skilled in the art, and should not be regarded as limitations on the term.

[0025] In order to solve the above problems, in the first aspect, the utility model provides an exhaust induced draft fan, such as Figure 1As shown in the figure, it includes an air induction module and a transmission module. The air induction module includes an air inlet 1, a casing 2 connected to the air inlet 1 and having a blower impeller disposed therein, and an air outlet 7. The transmission module includes a bearing housing 3 and a main shaft rotatably mounted to the bearing housing 3 and drivingly connected to the blower impeller. A cooling impeller 10 is provided on the main shaft between the casing 2 and the bearing housing 3. The cooling impeller 10 is arranged to rotate with the main shaft and blow cooling air towards the bearing housing 3. A cooling device is also provided in the bearing housing 3.

[0026] When the exhaust gas induced draft fan operates, the main shaft can be driven to rotate, thereby driving the blower impeller drivingly connected to the main shaft to rotate, forming a negative pressure at the air inlet 1, and quickly discharging the exhaust gas from the air outlet 7 through the air duct formed by the casing 2. The bearing housing 3 provided in the middle section of the main shaft supports the main shaft and plays a role in positioning the main shaft when it rotates. The cooling impeller 10 installed between the casing 2 and the bearing housing 3 is driven to rotate as the main shaft rotates, thereby forming an air flow blowing towards the bearing housing 3 along the axial direction of the main shaft, and forcibly dissipating heat from the bearing housing 3. By forcibly dissipating heat from the bearing housing 3 through the air flow generated by the cooling impeller 10 in the above technical solution, the temperature of the bearings in the bearing housing 3 can be reduced to the required operating temperature range, and it can cooperate with the cooling device in the bearing housing 3, thereby ensuring that the exhaust gas induced draft fan can operate stably for a long time.

[0027]

[0028] Table 1 Temperatures at each measurement point of the exhaust gas induced draft fan before and after installing the cooling impeller

[0029] The temperature reduction effect of each component on the exhaust gas induced draft fan by installing the cooling impeller is shown in Table 1.

[0030] Preferably, the cooling device in the bearing housing 3 can be a water cooling device. By respectively sleeving water cooling sleeves on each bearing in the bearing housing 3 and connecting the water inlet pipe and the water outlet pipe. When the water cooling device operates, the cooling water enters the water cooling sleeve through the water inlet pipe and absorbs the heat on the bearing, and then is discharged through the water outlet pipe. Through the water cooling device, the bearings in the bearing housing can be directly cooled, and cooperate with the cooling air generated by the cooling impeller 10 to cool the inner and outer parts of the entire bearing housing 3, so that the bearing housing 3 and its internal bearings can operate at their operating temperatures, enabling the exhaust gas induced draft fan to operate normally for a long time.

[0031] Preferably, as Figure 3 and Figure 4As shown, the heat dissipation impeller 10 is a semi-open impeller coaxially fixed on the main shaft, with its back plate facing the housing 2 and the blades facing the bearing box 3. When the exhaust induced draft fan is working, the heat dissipation impeller 10 is driven by the main shaft to rotate, generating cooling air blowing toward the bearing box 3 and the motor 5, thereby dissipating heat. By using a semi-open impeller, it is possible to reduce the hot air drawn into the surrounding of the housing 2, thereby reducing the temperature of the cooling air, so as to achieve a better cooling effect.

[0032] Preferably, Figure 4 As shown, the projection area of the heat dissipation impeller 10 in the axial direction of the main shaft is larger than the projection area of the bearing box 3 in the axial direction of the main shaft. Due to direct contact with the discharged high-temperature exhaust gas, the temperature of the surface of the casing 2 is much higher than the room temperature, and the heat thereon will be transferred to the surface of the bearing box 3 opposite to it by means of thermal radiation. By using the heat dissipation impeller 10 whose projection area in the axial direction of the main shaft is larger than the projection area of the bearing box 3 in the axial direction of the main shaft, the bearing box 3 can be completely shielded behind the heat dissipation impeller 10, thereby completely blocking the heat radiation of the casing 2 to the bearing box 3, and reducing the temperature of the bearing box 3 by reducing the heat received by the bearing box 3, so that it can always be at its working temperature, thereby ensuring that the exhaust draft fan can work normally.

[0033] Preferably, a lubricating device for lubricating the bearings disposed therein is also provided in the bearing box 3. Through the lubricating device, the bearings driven by the main shaft can be lubricated when the main shaft rotates, so as to ensure the normal operation of the bearings and thus the normal operation of the exhaust draft fan.

[0034] Preferably, the main shaft extends into the inner cavity of the casing 2, is transmission-connected to the fan impeller, and a seal is provided at the position where the main shaft passes through the casing 2. When the exhaust draft fan is working, the fan impeller to which it is transmission-connected is rotated by rotating the main shaft extending into the casing 2, thereby leading the exhaust gas from the air inlet 1 to the air outlet 7. The seal at the place where the main shaft passes through the casing 2 can ensure that only the air inlet 1 and the air outlet 7 on the casing 2 are connected to the outside world, thereby ensuring that the air pressure environment in the casing 2 is stable and the exhaust gas can be sucked out. At the same time, the seal can also prevent high-temperature exhaust gas from leaking from the casing 2 and contacting the bearing box 3 and the motor 5 to cause overheating, and can effectively ensure that the temperature of the bearing box 3 and the motor 5 is not affected by the high-temperature exhaust gas and can work normally.

[0035] Preferably, Figure 2As shown in the figure, the casing 2 is a volute casing, and a spiral air duct centered on the fan impeller is arranged inside it. The air inlet 1 and the air outlet 7 are connected to this duct. When the exhaust gas induced draft fan operates, the exhaust gas enters the casing 2 from the air inlet 1 under the action of the fan impeller and moves spirally inside the volute casing to the air outlet 7. The starting point of the spiral air duct in the volute casing is the air inlet 1, and the end point is the air outlet 7. From the air inlet 1 to the air outlet 7, the cross-sectional area of the spiral air duct gradually increases, so that a greater pressure can be obtained at the air inlet 1, thereby increasing the amount of exhaust gas generated by the industrial furnace that it can suck away. At the same time, the spiral structure of the volute casing helps to evenly guide the exhaust gas to the entire outlet area, avoiding the generation of eddy currents or backflows in the exhaust gas airflow at the outlet, thereby avoiding energy loss in the exhaust gas airflow and enabling it to be discharged from the casing 2 through the air outlet 7 more quickly.

[0036] Preferably, as Figure 1 shown, one end of the bearing box 3 away from the air induction module is provided with a motor 5, and the main shaft passes through the bearing box 3 and extends to be connected to the motor 5 through a coupling 4. When the exhaust gas induced draft fan works, the motor 5 drives the main shaft to rotate through the coupling 4, thereby driving the fan impeller to rotate and making the exhaust gas induced draft fan operate. By arranging the motor 5 away from the air induction module, while providing power to the exhaust gas induced draft fan, it can ensure that the motor 5 is not affected by the high-temperature exhaust gas in the air induction module, enabling it to work at a normal temperature. When problems occur in the components of the exhaust gas induced draft fan, the main shaft can be quickly disassembled through the coupling 4, facilitating the repair or replacement of the components on the exhaust gas induced draft fan.

[0037] Preferably, as Figure 1 shown, the casing 2, the bearing box 3 and the motor 5 are installed on the fan base 6 at different heights, so that the main shaft can be placed horizontally. Different-height platforms are provided on the fan base 6. By setting the casing 2, the bearing box 3 and the motor 5 at different heights, on the premise that the main shaft fixed and positioned by the three can always be placed horizontally, the exhaust gas induced draft fan can adapt to different specifications of the casing 2, the bearing box 3 and the motor 5. The horizontally placed main shaft ensures that the main shaft and the components connected to it can work normally without colliding or the components being damaged due to the inclination or inaccurate positioning of the main shaft, thus ensuring the normal operation of the exhaust gas induced draft fan.

[0038] Preferably, as Figure 1 shown, the fan base 6 is installed on the installation base 9 through bolts, and a shock pad 8 surrounding the bolts is arranged between the fan base 6 and the installation base 9. Through the bolts, the fan base 6 and the components installed on it are detachably installed on the installation base 9, so that parts of the exhaust gas induced draft fan can be disassembled and replaced. Through the shock pad 8 surrounding the bolts, the vibration generated by the exhaust gas induced draft fan during operation can be reduced, thereby improving the stability of the exhaust gas induced draft fan and enabling it to work stably for a long time.

[0039] In a second aspect, the present utility model further provides a calcination furnace system, which includes the above-mentioned tail gas induced draft fan. By using the above-mentioned tail gas induced draft fan, the calcination furnace system can operate stably for a long time without being forced to shut down or even experiencing a safety accident due to the components in the tail gas induced draft fan exceeding their operating temperatures.

[0040] The preferred embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings. However, the present utility model is not limited thereto. Within the technical concept scope of the present utility model, various simple modifications can be made to the technical solutions of the present utility model, including combining various specific technical features in any suitable manner. To avoid unnecessary repetition, the present utility model will not separately describe various possible combination methods. But these simple modifications and combinations should also be regarded as the content disclosed by the present utility model and all fall within the protection scope of the present utility model.

Claims

1. An exhaust gas induced draft fan, characterized in that, including an air induction module, which includes a housing (2) having an air inlet (1) and an air outlet (7) and a blower impeller installed in the housing (2), and the blower impeller can be driven to rotate in the housing (2) to drain the exhaust gas from the air inlet (1) to the air outlet (7); and, a transmission module, which includes a bearing housing (3) and a main shaft rotatably installed on the bearing housing (3) and drivingly connected to the blower impeller. Wherein, a cooling impeller (10) is provided on the main shaft between the housing (2) and the bearing housing (3), and the cooling impeller (10) is arranged to be able to rotate with the main shaft and blow cooling air to the bearing housing (3), and a cooling device is also provided in the bearing housing (3).

2. The exhaust gas induced draft fan according to claim 1, characterized in that, The cooling impeller (10) is a semi-open impeller coaxially fixed on the main shaft.

3. The exhaust gas induced draft fan according to claim 1, wherein, The projected area of the cooling impeller (10) in the axial direction of the main shaft is larger than the projected area of the bearing housing (3) in the axial direction of the main shaft.

4. The exhaust gas induced draft fan according to claim 1, characterized in that, A lubricating device for lubricating the bearings provided inside it is also provided in the bearing housing (3).

5. The exhaust gas induced draft fan according to claim 1, characterized in that, The main shaft extends into the inner cavity of the housing (2) to be drivingly connected to the blower impeller, and a seal is provided at the position where the main shaft passes through the housing (2).

6. The exhaust gas induced draft fan according to claim 1, characterized in that, The housing (2) is a volute, and a spiral air duct centered on the blower impeller is provided inside it, and the air inlet (1) and the air outlet (7) are communicated with the air duct.

7. The exhaust gas induced draft fan according to claim 1, characterized in that, One end of the bearing housing (3) away from the air induction module is provided with a motor (5), and the main shaft passes through the bearing housing (3) and extends and is connected to the motor (5) through a coupling (4).

8. The exhaust gas induced draft fan according to claim 7, characterized in that, The housing (2), the bearing housing (3) and the motor (5) are installed on a blower base (6) at different heights, so that the main shaft is horizontally placed.

9. The exhaust gas induced draft fan according to claim 8, wherein The blower base (6) is installed on the installation base (9) by bolts, and a shock pad (8) surrounding the bolts is provided between the blower base (6) and the installation base (9).

10. A calciner system, characterized in that, including the exhaust gas induced draft fan according to any one of claims 1-9.

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