Multi-stage movable blade adjustable axial flow fan choked flow sealing device

Abstract

The utility model discloses a multistage movable blade adjustable axial flow fan choke sealing device which comprises a flexible sealing ring arranged at the joint of an air duct and a motor shaft, a sealing pressing plate is arranged on the outer side of the flexible sealing ring in a pressing mode, and an elastic gasket covers the outer side of the sealing pressing plate. The sealing pressing plate and the elastic gasket penetrate through the flexible sealing ring through a bolt and nut assembly to be connected with the air duct arm. According to the utility model, the radial clearance between the motor shaft and the air duct is almost zero by adopting the flexible seal, the normal rotation of the motor shaft is not influenced due to the adoption of the flexible material, and the axial, radial and circumferential movement of the flexible seal is ingeniously limited after the motor shaft is firmly fixed by the sealing pressing plate with the spikes, so that the reliability of the motor is improved. And displacement, displacement and falling in the use process are avoided.

Description

Technical Field

[0001] The utility model relates to an axial flow fan sealing device, in particular to a multi-stage movable blade adjustable axial flow fan choke sealing device. Background Art

[0002] The multi-stage axial flow fan with adjustable moving blades is a must-have for circulating fluidized bed boilers in thermal power plants. It is used to remove the high-temperature flue gas generated by boiler combustion, maintain the furnace pressure, form flowing flue gas, complete the heat exchange between flue gas and air, and discharge it to the fan flue after the dust collector. It is used to adjust the negative pressure stability of the boiler furnace.

[0003] However, the existing multi-stage adjustable blade axial flow fans have the following technical problems:

[0004] (1) When designing a multi-stage axial flow fan with adjustable moving blades, a large radial gap is set between the motor shaft and the fan housing to ensure that there is no friction between the motor shaft and the air duct.

[0005] (2) Due to the existence of radial clearance, a large amount of external air is sucked into the fan, which reduces the ability to remove smoke, affects the efficiency of the fan, and increases power consumption.

[0006] (3) The SNCR denitrification process of circulating fluidized bed boilers is prone to produce ammonium bisulfate, whose crystals will corrode subsequent equipment. The generation of ammonium bisulfate crystals is negatively correlated with temperature. The lower the temperature, the more it is generated. The flue gas temperature at the fan is about 140°C. When a large amount of ambient cold air below the flue gas temperature enters the fan, the flue gas temperature drops significantly. A large amount of ammonium bisulfate in the flue gas will condense on the fan casing and rotor surface, causing large-scale corrosion of the equipment and a significant increase in the failure rate. Utility Model Content

[0007] In order to solve the above technical problems, the technical solution provided by the utility model is: a multi-stage movable blade adjustable axial flow fan flow resistance sealing device, including a flexible sealing ring arranged at the connection between the air duct and the motor shaft, a sealing pressure plate is pressed on the outside of the flexible sealing ring, and the outside of the sealing pressure plate is covered with an elastic gasket, and the sealing pressure plate and the elastic gasket are connected to the air duct arm through the flexible sealing ring via a bolt and nut assembly.

[0008] The advantages of the utility model compared with the prior art are: the utility model adopts a flexible seal to make the radial gap between the motor shaft and the air duct almost zero. Due to the use of flexible materials, it has no effect on the normal rotation of the motor shaft. After it is firmly fixed by a sealing pressure plate with spikes, it cleverly limits the axial, radial and circumferential movements of the flexible seal, ensuring that it will not shift, run out of place or fall off during use; the utility model has a simple and reliable structure, and only needs a simple tightening nut in the later stage to ensure its long-term use, solves various problems caused by air leakage in the radial gap between the air duct and the motor, and safely and efficiently improves the efficiency of the fan, improves the degree of crystallization inside the fan, increases the service life of the fan, reduces the failure rate of the fan and other problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The utility model is a structural schematic diagram of a flow-blocking sealing device for an axial flow fan with multi-stage adjustable moving blades.

[0010] Figure 2 The utility model is an enlarged schematic diagram of the installation position of a choke sealing device of a multi-stage movable blade adjustable axial flow fan.

[0011] Figure 3 The utility model is a schematic diagram of the side structure of a sealing pressure plate in a flow-blocking sealing device of an axial flow fan with multi-stage adjustable moving blades.

[0012] Figure 4 The utility model is a schematic diagram of the inner structure of a sealing pressure plate in a choke sealing device of an axial flow fan with multi-stage adjustable moving blades. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0014] In the description of the embodiments of the present utility model, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate an orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, it is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0015] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0016] In the description of the embodiments of the present invention, "multiple" means at least 2.

[0017] In the description of the embodiments of the present utility model, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0018] Example:

[0019] Combined with Figure 1-4 The present embodiment discloses a flow-blocking sealing device for an axial flow fan with multi-stage adjustable moving blades, comprising a flexible sealing ring 3 arranged at the connection between the air duct 1 and the motor shaft 2. The flexible sealing ring 3 is made of rubber material. The inner wall of the flexible sealing ring 3 contacts the outer wall of the motor shaft 2. After installation, a transition fit is adopted between the motor shaft and the air duct, which can effectively block the ambient cold air from entering the interior of the fan; a sealing pressure plate 4 is pressed on the outer side of the flexible sealing ring 3, and an elastic gasket 5 is covered on the outer side of the sealing pressure plate 4. The sealing pressure plate 4 and the elastic gasket 5 are connected to the air duct 1 arm through a bolt and nut assembly 6 through the flexible sealing ring 3.

[0020] The sealing pressure plate 4 includes a main pressure plate 401 in contact with the outer wall of the flexible sealing ring 3, and a side pressure plate 402 in contact with the side wall of the flexible sealing ring 3. The main pressure plate 401 and the side pressure plate 402 form an L-shaped sealing pressure plate 4; a plurality of fixed teeth 403 that penetrate into the flexible sealing ring 3 are arranged on the side of the main pressure plate 401 that contacts with the flexible sealing ring 3. When in use, the fixed teeth 403 can penetrate into the flexible seal to effectively prevent the radial movement of the flexible seal, thereby ensuring that the flexible seal is firm and reliable and does not shift during use.

[0021] The above description of the utility model and its implementation methods is not restrictive. The drawings show only one implementation method of the utility model, and the actual structure is not limited thereto. In short, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention of the utility model, they should all fall within the protection scope of the utility model.

Claims

1. A multi-stage movable blade adjustable axial flow fan choke sealing device, characterized in that: It comprises a flexible sealing ring arranged at the connection between the air duct and the motor shaft, a sealing pressure plate is pressed on the outside of the flexible sealing ring, an elastic gasket is covered on the outside of the sealing pressure plate, and the sealing pressure plate and the elastic gasket are connected to the air duct arm through the flexible sealing ring via a bolt and nut assembly.

2. The multi-stage adjustable blade axial flow fan choke sealing device according to claim 1, characterized in that: The inner wall of the flexible sealing ring contacts the outer wall of the motor shaft.

3. The choke sealing device for an axial flow fan with multi-stage adjustable moving blades according to claim 1, characterized in that: The sealing pressure plate comprises a main pressure plate in contact with the outer wall of the flexible sealing ring, and a side pressure plate in contact with the side wall of the flexible sealing ring. The main pressure plate and the side pressure plate form an L-shaped sealing pressure plate.

4. The choke sealing device for an axial flow fan with multi-stage adjustable moving blades according to claim 3, characterized in that: The surface of the main pressure plate in contact with the flexible sealing ring is provided with a plurality of fixing teeth which penetrate into the flexible sealing ring.

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