JPS5977040A - Centrifugal oil mist separator for gas turbine - Google Patents

Abstract

PURPOSE:To reduce the amount of oil consumption by bleeding partially the air from the outlet of a compressor of a gas turbine, by allowing it to turn the blades in a certrifugal oil separator, and thereby collecting fine oil mist contained in the air in a great quantity. CONSTITUTION:At the bearing housing of a gas turbine on its centrifugal compressor side, the air at the outlet of the compressor is utilized for returning the oil to the gear box together with the air so as not to leak when the oil is sent to the bearing. Here the gear box is equipped with a centrifugal oil mist separator 27. In thie separator 27, a circular wire brush 29 is hung on a shaft 30 in a cylinder 28, and this shaft 30 is so arranged as capable of being driven by an air turbine 22 furnished outside the body 28. The brush 29 is rotated at a high speed by the air turbine 22 by utilizing the air bled out of the exhaust hole of the compressor to give this air a swirl so as to spatter the oil attached to the brush 29 off to its surrounding.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a centrifugal oil mist separator, and in particular to a centrifugal oil mist separator for use in a gas turbine gearbox.

As is well known, gas turbines, particularly small gas turbines for general industrial use, rotate at high speeds integrally with a centrifugal compressor. For this reason, industrial gas turbines perform extensive deceleration to drive, for example, generators. A gearbox including this speed reducer is attached adjacent to the centrifugal compressor, and the gearbox is naturally moistened with lubricating oil.

In such a gas turbine, if the packing and oil seal are in good condition, the oil consumption depends on when the oil mist is prevented from being discharged. However, the causes of the difficulty in separating oil mist are: ■ The oil mist is too fine, ■ The back pressure of the gearbox cannot be large (up to about 200 mmAq), and ■ The amount of air is large (0,1
-0.2m37sec), and oil consumption was large.

For this reason, conventional models include those with built-in steel wool or the like, and those that operate a centrifuge through gears from the rotating shaft, but in the case of gas turbines, air leaks into the gear box.

As mentioned above, since the amount is large, it cannot be separated sufficiently using steel wool or the like, and if a centrifugal separator is used, there will be a corresponding loss in output.

Therefore, the present invention was created to eliminate this conventional problem by extracting part of the air from the outlet of the centrifugal compressor of the gas turbine, thereby rotating the blades in the centrifugal oil separator.

The purpose is to collect a large amount of fine oil mist that resembles steam.

The configuration of the present invention will be explained below based on the embodiments shown in the accompanying drawings. Fig. 1 shows a sectional view of the main parts of a small gas turbine directly connected to a generator, where A is a centrifugal compressor and B is a The combustor, C indicates a turbine wheel.

In the centrifugal compressor A, 1 is the impeller, 2 is the diffuser, and 3 is the discharge part. In the combustor B, 4 is the combustor inner cylinder, (5) is the fuel injection valve, and 6 is the combustor inner cylinder 4. 8 indicates a scroll that forms a flow path for introducing combustion gas into the first-stage turbine nozzle 7 of the turbine wheel C and a flow path for introducing compressed air from the discharge part 3 into the combustor inner cylinder 4; First stage packet, 9 is second stage turbine nozzle, 10 is second stage packet, 11 is exhaust casing, 12
indicates a turbine axle, and the axle 12 is supported by a turbine-side bearing housing and a compressor-side bearing housing.

Next, the diffuser 2 has its base integrally formed with a cone-shaped support 13, and the support 13 has its base connected to a cylindrical body 14 to form a turbine-side bearing housing. A first stage turbine nozzle 7 is provided on the end face of the cylindrical body 14.
The base of is fixed. A turbine axle 12 is inserted through the cylindrical body 14, and a roller bearing 15 is interposed in the center between the two, and a labyrinth seal 16 is interposed on one side of the roller bearing 15. 17 indicates metal.

In the first embodiment shown in FIG. 1, the cone-shaped support 13 and the turbine axle 12 form a compressor rear cavity 18 for thrust load adjustment, and compressed air is introduced from the diffuser 2 through the gap 19. After balancing with the thrust generated in the centrifugal compressor A, the cone-shaped support 1
A conduit 27 leads to an air turbine chamber 21 from a discharge port 20 formed in the air turbine 3. The air turbine chamber 21 is
The air turbine 22, which is installed on the top surface of the gear box 26 and has the same size as the chamber 21, is directly connected to the centrifugal separator 23.
25 indicates an oil separation umbrella, and 25 indicates a discharge pipe.

With the above configuration, the air sucked from the suction part flows into the impeller 1, flows along the path formed by the blades of the impeller 1, rotates together with the impeller 1, and is centrifuged. It is compressed by the action of the force, becomes higher pressure than the inlet, and flows out from the impeller 1 with speed. And the discharge part 3
Since the velocity of is large, the velocity energy is converted into pressure energy in the diffuser 2. The compressed air released from the diffuser 2 enters the outer circumference of the scroll 6, and then enters the combustor B.
guided by. In the inner cylinder 4 of the combustor B, combustion is injected from the combustion injection valve 5 to form high-pressure combustion gas. The combustion gas is guided along the inner circumference of the scroll 6.

The pressure is introduced into the first-stage turbine nozzle 7, and the pressure drops at each stage of the turbine, causing the turbine axle 12 to rotate at high speed while being converted into velocity energy.

The high pressure air from the diffuser 2 passes through the gap 19 and is accumulated in the compressor rear cavity 18 for thrust load adjustment formed on the back surface of the compressor impeller 1, and is balanced with the thrust of the compressor.

Next, in the bearing housing on the compressor side, after oil is sent to the bearing, the oil returns to the gear box 26, but when the oil is sent to the bear link, it is centrifugally compressed to prevent it from leaking outside. High pressure air at the outlet of machine A is used to return the oil to the gearbox 26 along with the air.

Therefore, it is necessary to provide a pleaser device to exhaust air from the gear box 26. In particular, when the air is discharged, it becomes a mist containing oil mist, and the size of the oil mist particles is very small. Thus, the oil carried away by the air determines the oil consumption of the gas turbine.

Therefore, a centrifugal oil mist separator 27 as shown in FIG. 2 is attached to the gear box 26. The separator 27 has a cylindrical body 28. A circular wire brush 29 rotating within the main body 28 is provided on a hanging shaft 30, and the shaft 30 is driven by an air turbine 22 which is a drive source provided outside the main body 28. A supply pipe 31 communicating with the gear box 26 is inserted horizontally near the ceiling of the cylindrical main body 28, and a discharge pipe blade is inserted into the center of the bottom of the main body 28 with the blade positioned slightly above the bottom surface. The other end of the discharge pipe 32 is open to the atmosphere. An oil outlet 33 is provided at one corner of the bottom of the main body 28.

Therefore, the driving source is the air turbine 22, and by extracting air from the discharge port of the centrifugal compressor A and introducing it through the cooler, power is obtained to rotate the single circular wire brush 29 at high speed.The air containing oil mist is The air flows down to pass through the circular wire brush 29, giving the air a swirl and blowing off the oil adhering to the wire to the outer periphery.

As a result, only low-density air containing no oil is discharged from the discharge pipe 32.

Next, instead of the circular wire brush 29, a downward-facing tip 34 as shown in FIG. The upper part has a diameter smaller than the outer diameter of the tip book 34 by 6. Therefore, while the air discharged from the discharge pipe 32 is being diverted by the tip body 34, oil adheres to the tip body 34, and the attached oil is blown away by centrifugal force, and only the air is discharged.

Furthermore, the circular wire brush 29 and the drive source (22) may be replaced with a commercially available air grinder (a grinder using compressed air for internally grinding stones, etc.). In this case, the price can be extremely reduced because it is not a special order.

In summary, the present invention provides a rotating body that is driven by air extracted from a compressor outlet within an oil mist separator body that is provided with an oil mist-containing air supply port in the upper part and an oil outlet and an air discharge port in the lower part. This is a centrifugal type oil mist separator for gas turbines, which is provided in the middle and allows the oil to flow from the supply port through the rotating body to the discharge port, so it has the following effects.

■ Air containing oil mist is passed through a rotating body, and oil particles are attached to the rotating body and then released by centrifugal force, making it possible to process air containing a large amount of fine oil mist, making it suitable for gas turbines. It can be made suitable as an air breather for an attached gear box.

■Since the rotating body is driven by air extracted from the compressor outlet, the structure is simple and no special drive mechanism is required.

■Since fine oil mist can be collected, the amount of lubricating oil consumed by gas turbines can be reduced.

[Brief explanation of the drawing]

FIG. 1 shows an overall view of an embodiment of the present invention, FIG. 2 shows a main part of the first embodiment, and FIG. 3 shows a main part of a second embodiment. 22...Air turbine, 27...Centrifugal oil mist separator, 28...
Cylindrical main body, 29... Circular wire brush, 31... Supply pipe, 32... Discharge pipe. 33...Oil outlet, 34...Cop body, A...Centrifugal compressor. Representative Patent Attorney Yoshihiko Okabe Figure 2 Figure 3

Claims (1)

[Claims] Above is the air supply port containing oil mist, below is the air supply port containing oil mist.
Inside the main body of the oil mist separator, which has an oil outlet and an air outlet, a rotating body driven by air bled from the compressor outlet is installed in the middle, and the air in the gear box is passed through the rotating body from the supply port to the exhaust port. A centrifugal oil mist separator for gas turbines that allows air to flow.