CN219159236U - Negative pressure sealed centrifugal fan - Google Patents

Abstract

The utility model discloses a negative pressure sealed centrifugal fan which comprises a fan shell, a bearing support seat, a return air pipe and a main shaft, wherein the main shaft is erected by the bearing support seat, and the bearing support seat is fixedly connected with the end face of a through shaft of the fan shell through a flange plate at the end part; the bearing support seat inner cavity comprises a bearing chamber and a negative pressure chamber which are sealed and isolated, the negative pressure chamber is positioned at one end close to the fan shell, and the negative pressure chamber is communicated to an air inlet of the fan shell through the return air pipe. The negative pressure chamber of the centrifugal fan is integrated to one end of the bearing support seat facing the fan shell, so that the structure is compact, and the cantilever length of the fan main shaft is reduced.

Description

Negative pressure sealed centrifugal fan

Technical Field

The utility model relates to the technical field of centrifugal fans, in particular to a negative pressure sealed centrifugal fan.

Background

The centrifugal fan is a machine for increasing the pressure of gas and discharging the gas by means of input mechanical energy. Centrifugal fans are widely used for ventilation, dust removal and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings; ventilation and induced draft of boilers and industrial kilns; cooling and ventilation in air-conditioning devices and household appliances; drying and selecting grains; inflation and propulsion of wind tunnel wind source and air cushion ship, etc. The utility model patent with the publication number of CN217582570U discloses a rotating shaft sealing deodorization device of a centrifugal fan, which comprises a fan shell, wherein one side of the fan shell is connected with an air inlet pipe, a shield is arranged on the other side of the fan shell opposite to the air inlet pipe, a fan rotating shaft is arranged in the middle of the shield, one end, which penetrates through the shield and is positioned in the fan shell, of the fan rotating shaft is connected with a fan blade fan, and a negative pressure pipe is connected between the air inlet pipe and the shield. According to the technical scheme, the leaked odor is sucked into the inlet of the air inlet pipe of the fan through the negative pressure pipe, so that the odor is prevented from diffusing everywhere, and the problem of leakage of the odor at the sealing position of the rotating shaft of the centrifugal fan of the garbage power plant is effectively solved. The utility model patent with publication number of CN217129890U discloses a negative pressure sealing device of a centrifugal fan, which comprises a shell, an air inlet pipe, a shell, a bolt, a conveying pipe, a connecting pipe, a valve, a driving shaft, a rotating shaft, an impeller, a sleeve shaft, a screw, a pressing plate, a sealing gasket, fan blades, a sleeve, a mounting plate and a screw. An air inlet pipe is fixedly connected to one side of the shell, the other side of the shell is fixedly connected with the shell through bolts, the air inlet pipe and the shell are respectively and fixedly connected with two ends of the conveying pipe, the bottom end of the conveying pipe is communicated with a connecting pipe, a valve is fixedly installed at the end part of the connecting pipe, the side wall of the shell is in penetrating and sleeving connection with a sleeve shaft, the sleeve shaft is fixedly connected with a pressing plate through a screw, a sealing gasket is arranged between the pressing plate and the sleeve shaft, and the sealing gasket is in embedded connection with the inside of the sleeve shaft; the negative pressure formed at the air inlet pipe can realize effective sealing of the shell, so that the problem of dust discharge in air caused by air leakage can be avoided, and leakage air can be prevented from entering the centrifugal fan again to avoid the problem of dust leakage in the air. Although the above patent sets up sealed negative pressure room through the casing mounting hole department at the fan main shaft, will leak dust or foul smell and draw back fan entrance again, among the above-mentioned disclosed technical scheme, because the independent setting of negative pressure room has increased the cantilever length of fan main shaft, leads to the fan impeller end to take place the tremble easily, and the noise increases, and the life-span of bearing shortens.

Therefore, there is a need to develop a negative pressure sealed centrifugal fan to address the above problems.

Disclosure of Invention

The utility model aims to provide a centrifugal fan with negative pressure seal, wherein a negative pressure chamber is integrated at one end of a bearing support seat, which faces to a fan shell, so that the structure is compact, and the cantilever length of a fan main shaft is reduced.

In order to solve the technical problems, the utility model adopts the following technical scheme:

the utility model discloses a negative pressure sealed centrifugal fan which comprises a fan shell, a bearing support seat, a return air pipe and a main shaft, wherein the main shaft is erected by the bearing support seat, and the bearing support seat is fixedly connected with the end face of a through shaft of the fan shell through a flange plate at the end part; the bearing support seat inner cavity comprises a bearing chamber and a negative pressure chamber which are sealed and isolated, the negative pressure chamber is positioned at one end close to the fan shell, and the negative pressure chamber is communicated to an air inlet of the fan shell through the return air pipe.

Further, the air return pipe is communicated with the air inlet, and the air return pipe is provided with a check valve which can prevent reverse flow ventilation from the air inlet to the negative pressure chamber.

Further, the return air pipe comprises a first return air pipe and a second return air pipe, the first return air pipe is communicated between the negative pressure chamber and the check valve, and the second return air pipe is communicated between the check valve and the air inlet.

Further, the automatic ash-blowing device further comprises a first manual valve and a tee joint, wherein the first manual valve and the tee joint are connected in series on the second air return pipe, the first manual valve is close to the check valve, and an ash blowing pipe is arranged on a branch pipe of the tee joint.

Further, a second manual valve is arranged on the ash blowing pipe.

Further, a quick connector is arranged at the end part of the ash blowing pipe.

Further, the return air pipe spans the fan shell above the vertical direction, and elbow pipe fittings convenient to detach are arranged at the tops of the first return air pipe and the second return air pipe.

Further, the root of the first return air pipe is fixedly connected to the top wall of the negative pressure chamber, and the root of the second return air pipe is fixedly connected to the top wall of the air inlet.

Compared with the prior art, the utility model has the beneficial technical effects that:

according to the negative pressure sealed centrifugal fan, the negative pressure chamber is integrated to one end, close to the fan shell, of the bearing support seat and is communicated to the air inlet through the return air pipe, so that a negative pressure isolation chamber can be formed at the shaft hole of the fan shell, and the air quantity leaked from the clearance of the shaft hole is pumped back to the air inlet, so that leakage to the outside is avoided. The negative pressure chamber of the centrifugal fan is integrated at one end of the bearing support seat facing the fan shell, the structure is compact, the cantilever length of the main shaft of the fan is reduced, the running of the impeller is stable and reliable, and the noise is low.

In addition, through the setting of check valve, centrifugal fan shut down and start-up in-process, negative pressure chamber negative pressure degree is low, can prevent the pipeline in this moment and carry the gas medium reverse flow, especially when carrying to wrap up in the gas medium and hold in the particulate impurity, can prevent that particulate impurity from entering into the negative pressure chamber. Through setting up of manual valve one, tee bend and blowing pipe, introduce compressed air from the blowing pipe, can regularly sweep the clearance to the second return air pipe that blocks up solid particle impurity easily. Closing the manual valve reduces the impact of the purge compressed air on the check valve and the first return air pipe. The elbow pipe fittings convenient to detach are arranged at the tops of the first return air pipe and the second return air pipe, so that the elbow pipe fittings can be detached, overhauled and maintained thoroughly during regular maintenance; the bottom ends of the first return air pipe and the second return air pipe are welded, so that loosening and falling-off in the long-term operation process are avoided.

Drawings

The utility model is further described with reference to the following description of the drawings.

FIG. 1 is a schematic diagram of a front view structure of a centrifugal fan with negative pressure seal according to the utility model;

FIG. 2 is a schematic diagram of a left-hand structure of a host portion according to the present utility model;

fig. 3 is a schematic view of a sectional structure of a bearing support seat portion according to the present utility model.

Reference numerals illustrate: 1. a blower housing; 101. an air inlet; 102. an air outlet; 2. a bearing support; 201. a support base; 202. a bearing chamber; 203. a negative pressure chamber; 3. a first return air pipe; 4. a non-return valve; 5. a first manual valve; 6. a tee joint; 7. a second manual valve; 8. a lance tube; 9. a second return air pipe; 10. a main shaft; 11. a belt wheel; 12. a belt; 13. a motor; 14. and a base.

Detailed Description

The utility model has the core of providing a centrifugal fan with negative pressure seal, wherein a negative pressure chamber is integrated at one end of a bearing support seat facing a fan shell, the structure is compact, and the cantilever length of a fan main shaft is reduced.

The following description of the embodiments of the present utility model will be made in detail with reference to the accompanying drawings, wherein it is apparent that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present utility model and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

Referring to the drawings, FIG. 1 is a schematic diagram of a main view structure of a centrifugal fan with negative pressure seal according to the present utility model; FIG. 2 is a schematic diagram of a left-hand structure of a host portion according to the present utility model; fig. 3 is a schematic view of a sectional structure of a bearing support seat portion according to the present utility model.

In one embodiment, as shown in fig. 1-3, a centrifugal fan with negative pressure seal comprises a fan shell 1, a bearing support seat 2, a return air pipe, a main shaft 10, a belt pulley 11, a belt 12, a motor 13 and a stand 14. The bottom of the bearing support seat 2 is mounted on the stand 14 through a support base 201. The bearing support seat 2 is fixedly connected with the shaft penetrating end face of the fan shell 1 through a flange plate at the end part of the bearing support seat 2 through a bearing erection main shaft 10. The working end of the main shaft 10 is connected with an impeller in the fan shell 1, the driving end of the main shaft 10 is provided with the belt wheel 11 and is connected to an output belt wheel of the motor 13 through a belt 12 in a transmission way, and the motor 13 is arranged on a machine base 14. The inner cavity of the bearing support seat 2 comprises a bearing chamber 202 and a negative pressure chamber 203 which are sealed and isolated, the negative pressure chamber 203 is positioned at one end close to the fan housing 1, and the negative pressure chamber 203 is communicated with the air inlet 101 of the fan housing 1 through the return air pipe.

Through integrating the negative pressure chamber 203 to the end of the bearing support seat 2, which is close to the fan housing 1, and communicating to the air inlet 101 through the return air pipe, a negative pressure isolation chamber can be formed at the shaft hole of the fan housing 1, and the air quantity leaked from the shaft hole gap is pumped back to the air inlet 101, so that leakage to the outside is avoided. The negative pressure chamber of the centrifugal fan is integrated at one end of the bearing support seat facing the fan shell, the structure is compact, the cantilever length of the main shaft of the fan is reduced, the running of the impeller is stable and reliable, and the noise is low.

In one embodiment of the present utility model, as shown in fig. 1 and 2, the negative pressure sealed centrifugal fan of the present utility model further comprises a check valve 4, wherein the check valve 4 is communicated with the return air pipe and can prevent reverse flow ventilation from the air inlet 101 to the negative pressure chamber 203.

Through the setting of check valve 4, centrifugal fan shut down and start-up in-process, negative pressure chamber 203 negative pressure degree is low, can prevent the pipeline in the transport gas medium reverse flow this moment, especially when wrapping up in the transport gas medium and holding the granule impurity, can prevent that the granule impurity from entering into negative pressure chamber 203.

In a specific embodiment of the present utility model, as shown in fig. 1 and 2, the return air duct includes a first return air duct 3 and a second return air duct 9, where the first return air duct 3 is connected between the negative pressure chamber 203 and the check valve 4, and the second return air duct 9 is connected between the check valve 4 and the air inlet 101.

Specifically, as shown in fig. 2, the negative pressure sealed centrifugal fan further comprises a first manual valve 5 and a tee joint 6, wherein the first manual valve 5 and the tee joint 6 are connected in series on a second return air pipe 9, the first manual valve 5 is close to the check valve 4, and a dust blowing pipe 8 is arranged on a branch pipe of the tee joint 6.

Specifically, as shown in fig. 2, a manual valve two 7 is provided on the lance tube 8. And the first manual valve 5 and the second manual valve 7 are butterfly valves.

Specifically, as shown in fig. 2, the end of the lance tube 8 is provided with a quick connector, and a compressed gas pipe for flushing can be quickly connected through the quick connector.

Through the arrangement of the first manual valve 5, the tee joint 6 and the ash blowing pipe 8, compressed air is introduced from the ash blowing pipe 8, and the second air return pipe 9 which is easy to block solid particle impurities can be purged and cleaned regularly. Closing the manual valve one 5 reduces the impact of the purge compressed air on the non-return valve 4 and the first return air pipe 3.

In a specific embodiment of the present utility model, as shown in fig. 1 to 3, the return air pipes span the fan housing 1 vertically above, and the top parts of the first return air pipe 3 and the second return air pipe 9 are respectively provided with elbow pipe fittings which are convenient to detach.

Specifically, the root of the first return air pipe 3 is welded and communicated with the top wall of the negative pressure chamber 203, and the root of the second return air pipe 9 is welded and communicated with the top wall of the air inlet 101.

The elbow pipe fittings convenient to detach are arranged at the top parts of the first return air pipe 3 and the second return air pipe 9, so that the disassembly, the overhaul and the maintenance can be carried out thoroughly during the regular maintenance; the bottom ends of the first return air pipe 3 and the second return air pipe 9 are welded, so that loosening and falling-off in the long-term operation process are avoided.

The utility model relates to a working principle of a negative pressure sealed centrifugal fan, which comprises the following steps: in the operation process, the motor 13 drives the belt pulley 11 to rotate through the belt 12, the main shaft 10 transmits torque and rotating speed to the impeller, and the impeller centrifugally blows in the volute of the fan shell 1 to continuously pump the gas medium in the pipeline from the air inlet 101 to the air outlet 102. The negative pressure chamber 203 of the bearing support seat 2, which is close to one end of the fan shell 1, is communicated to the air inlet 101 through the return air pipe, negative pressure is formed in the negative pressure chamber 203 by utilizing negative pressure at the air inlet 101, and then a negative pressure isolation chamber is formed at the shaft hole of the fan shell 1, and the air quantity leaked from the clearance of the shaft hole is pumped back to the air inlet 101, so that leakage to the outside is avoided. The second return air pipe 9 is cleaned regularly, when cleaning, the centrifugal fan stops working firstly, the first manual valve 5 is required to be closed, the compressed air supply hose is connected to a quick connector at the end part of the ash blowing pipe 8 by adopting a pipe joint, the second manual valve 7 is manually opened and closed to be repeatedly operated for not less than three times, the second return air pipe 9 is purged in a pulse mode, after purging is completed, the compressed air supply hose is disassembled, the second manual valve 7 is closed, the first manual valve 5 is opened, and the centrifugal fan enters a standing state when in operation.

According to the negative pressure sealed centrifugal fan, the negative pressure chamber 203 is integrated to one end, close to the fan shell 1, of the bearing support seat 2 and is communicated to the air inlet 101 through the return air pipe, so that a negative pressure isolation chamber can be formed at the shaft hole of the fan shell 1, and the air quantity leaked from the gap of the shaft hole is pumped back to the air inlet 101, so that leakage to the outside is avoided. The negative pressure chamber of the centrifugal fan is integrated at one end of the bearing support seat facing the fan shell, the structure is compact, the cantilever length of the main shaft of the fan is reduced, the running of the impeller is stable and reliable, and the noise is low. In addition, through the setting of check valve 4, centrifugal fan shut down and the start-up in-process, negative pressure chamber 203 negative pressure degree is low, can prevent the pipeline in the transport gas medium reverse flow this moment, especially when carrying and being wrapped up in the particulate impurity in the transport gas medium, can prevent that particulate impurity from entering into negative pressure chamber 203. Through the arrangement of the first manual valve 5, the tee joint 6 and the ash blowing pipe 8, compressed air is introduced from the ash blowing pipe 8, and the second air return pipe 9 which is easy to block solid particle impurities can be purged and cleaned regularly. Closing the manual valve one 5 reduces the impact of the purge compressed air on the non-return valve 4 and the first return air pipe 3. The elbow pipe fittings convenient to detach are arranged at the top parts of the first return air pipe 3 and the second return air pipe 9, so that the disassembly, the overhaul and the maintenance can be carried out thoroughly during the regular maintenance; the bottom ends of the first return air pipe 3 and the second return air pipe 9 are welded, so that loosening and falling-off in the long-term operation process are avoided.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.

The above embodiments are only illustrative of the preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model, and various modifications and improvements made by those skilled in the art to the technical solutions of the present utility model should fall within the protection scope defined by the claims of the present utility model without departing from the design spirit of the present utility model.

Claims (8)

1. The negative pressure sealed centrifugal fan is characterized by comprising a fan shell (1), a bearing support seat (2), a return air pipe and a main shaft (10), wherein the main shaft (10) is erected by the bearing support seat (2) through a bearing, and the bearing support seat (2) is fixedly connected with the through shaft end face of the fan shell (1) through a flange plate at the end part; the inner cavity of the bearing support seat (2) comprises a bearing chamber (202) and a negative pressure chamber (203) which are sealed and isolated, the negative pressure chamber (203) is positioned at one end close to the fan shell (1), and the negative pressure chamber (203) is communicated to an air inlet (101) of the fan shell (1) through an air return pipe.

2. The negative pressure sealed centrifugal fan according to claim 1, wherein: the air return pipe also comprises a check valve (4), wherein the check valve (4) is communicated with the air return pipe and can prevent reverse flow ventilation from the air inlet (101) to the negative pressure chamber (203).

3. The negative pressure sealed centrifugal fan according to claim 2, wherein: the return air pipe comprises a first return air pipe (3) and a second return air pipe (9), the first return air pipe (3) is communicated between the negative pressure chamber (203) and the check valve (4), and the second return air pipe (9) is communicated between the check valve (4) and the air inlet (101).

4. A negative pressure sealed centrifugal fan according to claim 3, wherein: the automatic ash-blowing device is characterized by further comprising a first manual valve (5) and a tee joint (6), wherein the first manual valve (5) and the tee joint (6) are connected in series on the second air return pipe (9), the first manual valve (5) is close to the check valve (4), and an ash blowing pipe (8) is arranged on a branch pipe of the tee joint (6).

5. The negative pressure sealed centrifugal fan according to claim 4, wherein: a manual valve II (7) is arranged on the ash blowing pipe (8).

6. The negative pressure sealed centrifugal fan according to claim 4 or 5, wherein: the end part of the ash blowing pipe (8) is provided with a quick connector.

7. A negative pressure sealed centrifugal fan according to claim 3, wherein: the return air pipe spans the fan shell (1) above the vertical, and elbow pipe fittings convenient to detach are arranged at the tops of the first return air pipe (3) and the second return air pipe (9).

8. The negative pressure sealed centrifugal fan of claim 7, wherein: the root of the first return air pipe (3) is fixedly connected to the top wall of the negative pressure chamber (203), and the root of the second return air pipe (9) is fixedly connected to the top wall of the air inlet (101).

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