JP2004324594A - Oil mist collecting method and oil mist separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To collect oil mist suspended in a bearing chamber at a high collection rate. <P>SOLUTION: In order to recover oil from a swirling flow 8 containing oil mist and whirling in an inside of the bearing chamber 6, a tunnel-shaped flow regulation body 16 takes a part of the swirling flow inside from an upstream end and spouts it from a downstream end. The body is gradually narrowed in flow passage area from upstream to downstream. The body is attached to an inner peripheral surface 6a of the bearing chamber, accelerates the part of the swirling flow and sprays the accelerated swirling flow onto ribs 12. Filters of honeycomb material or porous material are preferably arranged in a flow path of the swirling flow, and the part of the swirling flow is made to pass through the filters. This provides an oil mist separator combined with technique of inertia dust-collection and filter dust-collection. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for collecting oil mist floating in gas swirling in a bearing chamber and an oil mist separator.
[0002]
[Prior art]
FIG. 5 is a perspective view showing a part of the internal structure of a general gas turbine engine used for an aircraft or the like. A turbine shaft 51 that transmits rotational power of a turbine rotor to a compressor and a fan is provided on a central axis of the gas turbine engine 50 in an axial direction. The turbine shaft 51 is formed by a structure 52 that forms a housing of the engine 50. It is supported via a bearing 4. Oil for lubrication and cooling is always supplied to the bearing 4 that rotates in contact with the turbine shaft 51.
[0003]
Generally, the bearing 4 supporting the turbine shaft 51 is housed in a bearing chamber, and the bearing chamber is housed in a high-pressure air chamber maintained at a higher pressure than the bearing chamber. The high-pressure air in the high-pressure air chamber has a labyrinth seal in the bearing chamber so that oil does not leak from the bearing chamber.
[0004]
The oil supplied into the bearing chamber through the feed element tube 56a is sprayed toward the bearing 4 to lubricate and cool the bearing. The air in the bearing chamber is swirling under the influence of the turbine shaft 51 rotating at high speed, and the oil mist floating in the bearing chamber is formed on the inner peripheral surface of the bearing chamber up to a certain size by the centrifugal force of the swirling flow. It adheres and is centrifuged from the air, and is sucked and collected as liquid oil from the lower return element tube 56b. The air in the bearing chamber from which a certain amount of oil mist has been separated is pushed out by the air flowing from the high-pressure air chamber, and is exhausted from a center vent formed in the turbine shaft 51. Note that Patent Document 1 is disclosed as a prior document related to the present invention.
[0005]
[Patent Document 1]
US Pat. No. 5,776,229 [0006]
[Problems to be solved by the invention]
In the above-described oil recovery by centrifugation, the fine oil mist is exhausted together with the air without being centrifuged, leading to an increase in the amount of oil consumption and the number of times of oil supply, which is a problem in operation.
[0007]
Therefore, in recent years, an oil mist separator is often provided in a path extending from the bearing chamber to the center vent. The oil mist separator collects the oil, and sends the oil to the element pipe 56b for oil recovery.
[0008]
However, it cannot be said that the conventional oil mist separator 62 has yet achieved sufficient oil recovery, and it has been desired to further improve the oil recovery rate.
[0009]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a simple and inexpensive method for collecting oil mist, which can collect oil mist in a swirling flow in a bearing chamber at a high recovery rate, and an oil mist It is intended to provide a separator.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the present invention relates to a method for collecting oil mist for recovering oil from a swirling flow including an oil mist swirling inside a cylindrical bearing chamber containing a bearing that supports a rotating body. Wherein the swirling flow at a radially outer position in the bearing chamber is accelerated, and the accelerated swirling flow is sprayed on a rib protruding from an inner peripheral surface of the bearing chamber to cause oil mist to adhere to the rib. Provided is a method for collecting oil mist.
The method for collecting oil mist of the present invention is based on the so-called inertial dust collection technique. Inertial dust collection is a dust collection method that utilizes the property that dust in the gas changes even if the direction of the gas changes. For this reason, in the present invention, the swirling flow swirling at the radially outer position in the bearing chamber is accelerated, so that the direction of the accelerated swirling flow is suddenly changed, thereby increasing the efficiency of oil mist recovery by inertial dust collection. By efficiently collecting the oil mist, it is possible to reduce the oil consumption and improve the economical efficiency in operation.
[0011]
It should be noted that, by simultaneously collecting the oil mist on the path from the conventional bearing chamber to the center vent and collecting the oil on the peripheral wall of the bearing chamber of the present invention, it is possible to recover the oil with higher efficiency.
In addition to the above, it is also preferable that an oil mist is attached to the surface of the filter by passing a part of the swirling flow through a filter made of a honeycomb material or a porous material provided in the flow path.
In the present invention, in addition to the above-described inertial dust collection method, the oil mist is collected by a filter dust collection method, and more effective oil recovery can be achieved by these two methods. Here, the filter dust collection is a dust collection method in which particles are separated when a gas passes through a filter material.
In order to carry out the above-described method for collecting oil mist, the present invention provides an oil for recovering oil from a swirling flow including an oil mist which swirls inside a cylindrical bearing chamber accommodating a bearing for supporting a rotating body. A mist separator, which takes in a part of the swirling flow from the upstream end and jets it out from the downstream end, and on the inner peripheral surface of the bearing chamber so as to gradually narrow the flow area from upstream to downstream. An oil mist separator, comprising: an attached tunnel-shaped rectifier, and a rib protruding radially inward from the inner peripheral surface of the bearing chamber and blowing a swirling flow ejected from a downstream end of the rectifier. provide.
The present invention mounts a rectifying body formed in a tunnel shape with a gradually decreasing flow passage area on an inner peripheral surface of a cylindrical bearing chamber containing a bearing for supporting a rotating body such as a turbine shaft. This is an oil mist separator that collects oil mist by accelerating a part of the swirling flow taken in from the upstream end in the flow straightening body and spraying the same on a rib provided near the downstream end of the straightening body. That is, according to the present invention, the inertia force acting on the oil mist can be increased by accelerating a part of the swirling flow by the straightening body, and the efficiency of collecting the oil mist by the inertial dust collection can be increased.
Further, it is preferable that a filter made of a honeycomb material or a porous material is attached in a tunnel-shaped flow path formed by the rectifier.
By passing the swirling flow taken from the upstream end of the flow straightener through a filter provided in a tunnel-shaped flow path formed by the flow straightener, oil mist is attached to the surface of the filter, and the oil mist generated by the filter dust is removed. Recovery can be performed. The filter may be mounted so that all of the swirling flow flowing through the tunnel flow path passes through the filter, or may be mounted so that only a part thereof passes through the filter.
Further, it is also preferable that the rectifier is formed of a honeycomb material or a porous material.
Using a rectifier formed of a honeycomb material or a porous material in place of the filter, or together with the filter, accelerates a swirling flow swirling at a radially outer position in the bearing chamber to perform oil recovery by inertial dust collection. In addition, oil can be collected by filter dust collection.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the oil mist separator of the present invention will be described with reference to the drawings. In addition, the same reference numerals are given to the common parts in the respective drawings, and the duplicate description will be omitted.
FIG. 1 is an axial cross-sectional view showing a part of the internal structure of the gas turbine. The vicinity of the rear end of a turbine shaft 51 as a rotating body 2 is supported by a structure 52 that forms an engine housing via a bearing 4. It shows how it is. In this figure, the hatched space to the right is a bearing chamber 6 for accommodating the bearing 4, and the hatched part to the right is a high-pressure air chamber 7. The high-pressure air chamber 7 is maintained at a higher pressure than the bearing chamber 6, and the low-pressure bearing chamber is sealed with a labyrinth seal to contain oil.
Oil sucked by a pump from an oil tank (not shown) is sprayed into the bearing 4 rotating in contact with the turbine shaft 51 through an oil supply element tube 56a from a nozzle at the tip thereof in a mist form. Lubrication and cooling are performed.
[0013]
Here, a swirling flow is generated in the bearing chamber 6 due to the gas viscosity of the surface of the turbine shaft 51 rotating at high speed, and the oil mist blown to the bearings floats in the swirling flow.
A center vent 61 is formed in the turbine shaft 51 for exhausting the air flowing from the high-pressure air chamber 7 from the bearing chamber 6. A conventional oil mist that rotates together with the turbine shaft is formed in a portion where the center vent 61 opens. A separator 62 is attached, and the oil is collected by the oil mist separator 62.
The oil mist separator 10 of the present invention is attached to a part of the bearing chamber radially outside. In order to explain the structure of the oil mist separator, FIG. 2 schematically shows a sectional view taken along the line XX of FIG.
As shown in FIG. 2 (first embodiment), the cross section of the bearing chamber 6 is circular, and a turbine shaft 51 supported via the bearing 4 is disposed at the center. The turbine shaft is rotating at high speed in the clockwise direction, so that the swirling flow 8 in the bearing chamber is also rotating in the clockwise direction. Reference numeral 61 denotes a center vent hole formed in the turbine shaft.
On the inner peripheral surface 6a of the bearing chamber, four rectifiers 16 that form a tunnel-shaped flow path (hereinafter referred to as "tunnel flow path 3") between the inner peripheral surface 6a and the inner peripheral surface 6a of the bearing chamber are arranged at equal intervals on the same circumference. Installed. Each straightening body 16 takes in a part of the swirling flow 8 from the upstream end and gushes it from the downstream end, and the tunnel flow path 3 is narrowed so that its flow path area gradually decreases from upstream to downstream. Therefore, the swirling flow 8 taken in from the upstream end of the flow regulating body 16 is ejected in the tunnel flow path 3 with its flow velocity increased.
In this embodiment, a filter 14 made of a honeycomb material is provided in the tunnel flow path 3, and the swirling flow 8 taken in the tunnel flow path 3 flows through the pores of the filter 14 toward the downstream end. The honeycomb filter of the present embodiment is not particularly limited to this, and a porous metal, a porous sintered body, a mesh plate, or the like can be used.
Further, a rib 12 protruding radially inward is provided on the peripheral surface 6a of the bearing chamber near the downstream end of the flow regulating body 16. An accelerated swirling flow spouting from the downstream end of the flow regulating body 16 is blown to the rib 12.
According to the oil mist separator of this embodiment constituted by the rectifier 16, the filter 14, and the rib 12,
{Circle around (1)} A part of the swirling flow 8 having a large swirl radius swirling at the radially outer position of the bearing chamber 6 is taken into the tunnel flow path 3, and accelerated by the flow straightener 16 to increase the inertia force of the oil. By spraying the swirling flow in which the mist floats on the rib 12, a fine oil mist, which has conventionally been difficult to recover, can be attached to the rib 12 (inertial dust collection).
{Circle over (2)} The swirling flow 8 flowing through the tunnel flow path 3 passes through the filter 14 so that oil mist can adhere to the surface of the filter (filter dust collection).
A more effective oil recovery can be achieved by combining the above two dust collection methods.
The oil mist adhering to the peripheral surface 6a of the bearing chamber, the filter 14 and the ribs 12 accumulates as droplets, and then temporarily collects at the bottom of the bearing chamber 6 due to gravity, and is used as a return scavenge communicating with the bottom of the bearing chamber. It is discharged and collected from the pipe 56b.
FIG. 3 shows a second embodiment of the oil mist separator of the present invention. The flow regulating body 16 and the ribs 12 of the oil mist separator are configured in the same manner as the oil mist separator of the first embodiment, but in this embodiment, the filter provided in the tunnel flow path 3 in the first embodiment is used. 14 is provided outside the flow regulating body 16, that is, at a position radially inside the bearing chamber 6.
Since the filter 14 may hinder the smooth flow of the swirling flow, by arranging the filter 14 in this manner, the swirling flow flowing into the tunnel flow path 3 formed by the rectifier 16 is increased, and the inertial dust collection is performed. At the same time, the collection of oil mist can be promoted by the method described above, and the oil mist can be collected from the swirling flow that flows inside the bearing chamber 6 in the radial direction by the method of collecting dust with a filter.
FIG. 4 shows a third embodiment of the oil mist separator of the present invention. The flow regulating body 16 of the oil mist separator is formed of a honeycomb material (filter 14) having a certain thickness, and the holes of the honeycomb material pass a part of the swirling flow 8 flowing radially inside the bearing chamber 6 into a tunnel flow path. It is inclined to lead to 3. The tunnel passage 3 has a passage area gradually decreasing toward the downstream similarly to the above-described embodiment, and a rib 12 protruding is mounted on the peripheral surface 6a of the bearing chamber near the downstream end of the rectifier 16.
According to the oil mist separator of this embodiment, the swirl flow taken in from the upstream end of the flow regulating body 16 and the swirl flow introduced from the holes of the honeycomb material (filter 14) are accelerated in the tunnel flow path 3. As a result, the inertia force acting on the oil mist is increased, and a fine oil mist having a small particle size and a small weight, which could not be collected conventionally, is applied to the inner peripheral surface of the bearing chamber and the ribs by the method of inertial dust collection. At the same time, the oil mist can be collected by the filter dust collection method by allowing a part of the swirling flow flowing radially inside the bearing chamber to flow through the honeycomb material.
Note that the size of the flow regulating body 16 (tunnel flow path 3), the size of the rib 12, and the size of the filter 14 (honeycomb material) of the oil mist separator of the first to third embodiments can be variously changed. Therefore, efficient oil recovery is realized by determining the optimal sizes.
Although the specific embodiments of the oil mist separator of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the gist of the present invention. is there.
[0014]
【The invention's effect】
As described above, according to the method for collecting oil mist and the oil mist separator of the present invention, a fine oil mist having a small particle size and a small mass in a swirling flow in a bearing chamber, which could not be collected conventionally, can be inertized. It can be collected by dust collection techniques. In addition, it is preferable to incorporate a filter dust collecting method into the filter, so that more effective oil recovery can be achieved by a combination of the three dust collecting methods. The method and apparatus of the present invention can be implemented simply and inexpensively.
[Brief description of the drawings]
FIG. 1 is an axial sectional view showing a part of an internal structure of a gas turbine.
FIG. 2 is a sectional view showing an oil mist separator of the first embodiment.
FIG. 3 is a sectional view illustrating an oil mist separator according to a second embodiment.
FIG. 4 is a cross-sectional view illustrating an oil mist separator according to a third embodiment.
FIG. 5 is a perspective view showing a part of the internal structure of a general gas turbine engine.
[Explanation of symbols]
2 Rotating body 3 Tunnel flow path 4 Bearing 6 Bearing chamber 6a Inner peripheral surface of bearing chamber 7 High-pressure air chamber 8 Swirling flow 10 Oil mist separator 12 Rib 14 Filter 16 Rectifier 50 Gas turbine engine 51 Turbine shaft 52 Structure 56a For feed Element tube 56b Element tube 57 for return Oil cooler 61 Center vent 62 Oil mist separator (conventional type)

Claims (5)

An oil mist collecting method for recovering oil from a swirling flow including an oil mist that swirls inside a cylindrical bearing chamber containing a bearing that supports a rotating body,
An oil mist, comprising: accelerating a swirling flow at a radially outer position in the bearing chamber, spraying the accelerated swirling flow to a rib projecting from an inner peripheral surface of the bearing chamber, and adhering oil mist to the rib. Collection method. 2. The oil mist is attached to the surface of the filter by passing a part of the swirling flow through a filter made of a honeycomb material or a porous material provided in the flow path thereof. How to collect oil mist. An oil mist separator for recovering oil from a swirling flow including an oil mist that swirls inside a cylindrical bearing chamber containing a bearing that supports the rotating body,
A part of the swirling flow is taken in from the upstream end and jetted out from the downstream end, and a tunnel-shaped is attached to the inner peripheral surface of the bearing chamber so as to gradually narrow the flow area from upstream to downstream. Commutator and
An oil mist separator, comprising: a rib protruding radially inward from an inner peripheral surface of the bearing chamber and blowing a swirling flow spouted from a downstream end of the flow regulating body. The oil mist separator according to claim 3, wherein a filter made of a honeycomb material or a porous material is mounted in a tunnel-shaped flow path formed by the flow regulating body. The oil mist separator according to claim 3, wherein the rectifier is formed of a honeycomb material or a porous material.

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