JP4296829B2 - Oil mist collection method and oil mist separator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for collecting oil mist floating in a 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 in an aircraft or the like. A turbine shaft 51 that transmits the rotational power of the turbine rotor to the compressor and the fan is provided in the axial direction on the central axis of the gas turbine engine 50. The turbine shaft 51 is formed by a structure 52 that forms a casing of the engine 50. It is supported via a bearing 4. The bearing 4 that rotates in contact with the turbine shaft 51 is always supplied with oil for lubrication and cooling.
[0003]
Generally, the bearing 4 that supports the turbine shaft 51 is housed in a bearing chamber, and the bearing chamber is housed in a high-pressure air chamber that is maintained at a higher pressure than the bearing chamber. The bearing chamber is labyrinth sealed so that oil does not leak out from the bearing chamber.
[0004]
Oil supplied through the feed element pipe 56a into the bearing chamber is sprayed toward the bearing 4 to lubricate and cool the bearing. The air in the bearing chamber is swirled by the influence of the turbine shaft 51 that rotates at a high speed, and the oil mist that floats in the bearing chamber remains on the inner circumferential surface of the bearing chamber up to a certain size due to the centrifugal force of the swirling flow. It adheres and is centrifuged from the air, and is sucked and collected from the lower return element tube 56b as liquid oil. 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 exhausted from the center vent formed in the turbine shaft 51. Patent Document 1 is disclosed as a prior document related to the present invention.
[0005]
[Patent Document 1]
US Pat. No. 5,776,229 specification
[Problems to be solved by the invention]
In the oil recovery by the centrifugal separation described above, the fine oil mist is exhausted together with the air without being centrifuged, resulting in an increase in oil consumption and the number of times of oil supply.
[0007]
Therefore, in recent years, an oil mist separator is often provided in a path extending from the bearing chamber to the center vent, and the oil is collected by the oil mist separator and sent to the element pipe 56b for oil collection.
[0008]
However, such a conventional oil mist separator 62 has not yet achieved sufficient oil recovery, and further improvement of the oil recovery rate has been desired.
[0009]
The present invention has been made to solve the above-described problem, and can easily and inexpensively collect an oil mist and oil mist which can recover oil mist in a swirling flow in a bearing chamber at a high recovery rate. An object is to provide a separator.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is an oil mist collecting method 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. there are, to accelerate the swirling flow in the radially outer position of said bearing chamber by a tunnel-shaped flow rectifier attached to the inner circumferential surface of the bearing chamber, the protrusions and accelerated the swirling flow from the inner peripheral surface of the bearing chamber Oil mist is attached to the ribs by spraying on the ribs, and the rectifier takes in a part of the swirling flow from the upstream end in the swirling direction of the swirling flow and from the downstream end in the swirling direction of the swirling flow. spewing, and one in which progressively narrows the flow channel area as it proceeds from the upstream side of the turning direction to the downstream side of the turning direction, and wherein the oil To provide a list method of the collection.
The method for collecting oil mist of the present invention applies a so-called inertia dust collection technique. Inertial dust collection is a dust collection method that takes advantage of the property that the dust in the gas tends to go straight even if the direction of the gas changes. For this reason, in the present invention, the efficiency of oil mist recovery by inertia dust collection is enhanced by accelerating the swirling flow swirling around the radially outer position in the bearing chamber, thereby abruptly changing the direction of the accelerated swirling flow. By efficiently collecting the oil mist, it is possible to reduce oil consumption and improve operational economics.
[0011]
Note that the oil recovery with higher efficiency can be achieved by simultaneously collecting the oil mist in the path from the conventional bearing chamber to the center vent and the oil in the peripheral wall of the bearing chamber of the present invention.
In addition to the above, it is also preferable that 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, oil mist is recovered by a filter dust collection method in addition to the inertia dust collection method described above, and more effective oil recovery can be achieved by these two methods. Here, the filter dust collection is a dust collection method for separating particles when gas passes through the filter material.
In order to carry out the oil mist collecting method described above, the present invention provides an oil 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. a mist separator, which was ejected from the downstream end from the upstream end in the turning direction of the swirling flow capture a portion of the swirling flow inside the turning direction of the swirling flow, and, from the upstream side of the turning direction A tunnel-like rectifier attached to the inner peripheral surface of the bearing chamber so as to gradually narrow the flow path area as it moves to the downstream side in the turning direction, and protrudes radially inward from the inner peripheral surface of the bearing chamber, a rib swirling flow jetted from the downstream end of the rectifying body is blown to provide an oil mist separator which is characterized in that it consists of.
The present invention attaches a rectifier formed in a tunnel shape with a gradually decreasing flow path area to the inner peripheral surface of a cylindrical bearing chamber containing a bearing that supports 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 from the upstream end in the rectifier and spraying it on a rib provided in the vicinity of the downstream end of the rectifier. That is, according to the present invention, the inertial force acting on the oil mist can be increased by accelerating part of the swirling flow by the rectifier, and the oil mist recovery efficiency by the inertia dust collection can be increased.
Moreover, it is also preferable that a filter made of a honeycomb material or a porous material is attached in a tunnel-like flow path formed by the rectifier.
By passing the swirl flow taken from the upstream end of the rectifier through a filter provided in a tunnel-like flow path formed by the rectifier, the oil mist adheres to the surface of the filter, and the oil mist by the filter dust collection Recovery can be performed. The filter may be attached so that all of the swirling flow that flows through the tunnel-shaped flow path passes through the filter, or may be attached so that only a part thereof passes through the filter.
Furthermore, it is also preferable that the rectifying body is formed of a honeycomb material or a porous material.
At the same time as collecting oil by inertia dust collection by accelerating the swirling flow swirling around the radially outer position in the bearing chamber using a rectifier formed of a honeycomb material or a porous material together with the filter or in combination with the filter Oil recovery by filter dust collection can also be performed.
[0012]
DETAILED DESCRIPTION OF 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 code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.
FIG. 1 is a sectional view in the axial direction showing a part of the internal structure of a gas turbine, and the vicinity of the rear end of a turbine shaft 51, which is a rotating body 2, is supported by a structure 52 that forms a casing of an engine via a bearing 4. It shows how it is. In this figure, the space that is hatched to the right is the bearing chamber 6 that houses the bearing 4, and the portion that is hatched to the right is the high-pressure air chamber 7. The high-pressure air chamber 7 is kept at a higher pressure than the bearing chamber 6 and is sealed with a labyrinth seal from the low-pressure bearing chamber to contain oil.
The oil sucked out by a pump from an oil tank (not shown) is sprayed to the bearing 4 rotating in contact with the turbine shaft 51 from the nozzle at the tip thereof through an oil supply element pipe 56a. Lubrication and cooling are performed.
[0013]
Here, a swirl flow is generated in the bearing chamber 6 due to the gas viscosity on the surface of the turbine shaft 51 that rotates at high speed, and oil mist blown to the bearing floats in the swirl flow.
The turbine shaft 51 is formed with a center vent 61 for exhausting the air flowing from the high-pressure air chamber 7 from the bearing chamber 6, and a conventional oil mist that rotates together with the turbine shaft is formed at a portion where the center vent 61 opens. A separator 62 is attached, and 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 on the outside in the radial direction. In order to explain the structure of the oil mist separator, a sectional view taken along the line XX in FIG. 1 is schematically shown in FIG.
As shown in FIG. 2 (first embodiment), the bearing chamber 6 has a circular cross section, and a turbine shaft 51 supported via the bearing 4 is disposed at the center thereof. The turbine shaft rotates at high speed in the clockwise direction, so that the swirling flow 8 in the bearing chamber also rotates in the clockwise direction. Reference numeral 61 denotes a center vent hole formed in the turbine shaft.
Four rectifiers 16 forming a tunnel-like flow path (hereinafter referred to as “tunnel flow path 3”) between the bearing chamber inner circumferential surface 6a and the bearing chamber inner circumferential surface 6a are formed at equal intervals on the same circumference. It is attached. Each rectifier 16 takes a part of the swirling flow 8 from the upstream end and ejects it from the downstream end, and the tunnel flow path 3 gradually reduces the flow passage area from the swirling flow upstream to the swirling flow downstream. It is squeezed. Therefore, the swirling flow 8 taken from the upstream end of the rectifying body 16 is ejected at an increased flow velocity in the tunnel flow path 3.
In this embodiment, a filter 14 made of a honeycomb material is provided in the tunnel flow path 3, and the swirl flow 8 taken into the tunnel flow path 3 flows through the pores of the filter 14 toward the downstream end. Note that 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 also be used.
Further, a rib 12 protruding radially inward is provided on the bearing chamber inner circumferential surface 6 a in the vicinity of the downstream end of the rectifying body 16. The rib 12 is adapted to spray an accelerated swirling flow ejected from the downstream end of the rectifier 16.
According to the oil mist separator of this embodiment configured by the rectifying body 16, the filter 14, and the rib 12,
(1) Oil that has increased inertial force by taking a part of the swirl flow 8 having a large swirl radius swirling in the radially outer position of the bearing chamber 6 into the tunnel flow path 3 and accelerating it by the rectifier 16. By spraying the swirl flow in which the mist floats on the rib 12, fine oil mist, which has been difficult to recover in the past, can be attached to the rib 12 (inertia dust collection).
(2) When the swirling flow 8 flowing through the tunnel flow path 3 passes through the filter 14, oil mist can be attached to the surface of the filter (filter dust collection).
More effective oil recovery can be achieved by combining the two dust collection methods.
The oil mist adhering to the bearing chamber inner circumferential surface 6a, the filter 14 and the rib 12 is collected to form droplets, and then temporarily accumulated at the bottom of the bearing chamber 6 due to gravity and communicates with the bottom of the bearing chamber for return scavenging. It is discharged and collected from the pipe 56b.
FIG. 3 shows a second embodiment of the oil mist separator according to the present invention. The rectifier 16 and the rib 12 of this 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. 14 is provided outside the rectifying body 16, that is, at a radially inner position of the bearing chamber 6.
Since the filter 14 may impede the smooth flow of the swirling flow, the filter 14 is arranged in this manner, thereby increasing the swirling flow flowing into the tunnel flow path 3 formed by the rectifier 16 and inertial dust collection. The oil mist can be collected by the filter dust collecting technique from the swirling flow flowing in the radial inside of the bearing chamber 6 at the same time.
FIG. 4 shows a third embodiment of the oil mist separator according to the present invention. The oil mist separator rectifier 16 is formed of a honeycomb material (filter 14) having a certain thickness, and the holes of the honeycomb material pass through a part of the swirling flow 8 flowing radially inside the bearing chamber 6 as a tunnel flow path. Inclined to lead to 3. Further, the tunnel flow path 3 gradually decreases in the flow path area toward the downstream in the swirl direction of the swirl flow as in the above embodiment, and the protruding ribs 12 are formed on the bearing chamber peripheral surface 6a near the downstream end of the rectifier 16. It is attached.
According to the oil mist separator of the present embodiment, the flow velocity of the swirl flow taken from the upstream end of the rectifying body 16 and the swirl flow introduced from the hole of the honeycomb material (filter 14) is accelerated in the tunnel flow path 3. As a result, the inertial force acting on the oil mist is increased, and fine oil mist having a small particle size and light weight that could not be collected in the past is applied to the inner peripheral surface and rib of the bearing chamber by the inertia dust collection method. At the same time, the oil mist can be collected by a filter dust collection technique by allowing a part of the swirling flow flowing radially inside the bearing chamber to flow in the honeycomb material.
The size of the rectifier 16 (tunnel channel 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 obtaining the optimum size.
Although 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 various modifications can be made without departing from the gist of the present invention. is there.
[0014]
【The invention's effect】
As described above, according to the oil mist collecting method and the oil mist separator of the present invention, the inertia of the fine oil mist having a small particle size and a small mass in the swirling flow in the bearing chamber, which could not be collected conventionally. It can be recovered by dust collection. Further, preferably, a filter dust collecting technique is also incorporated in this, and a more effective oil recovery can be achieved by a combination of the three dust collecting techniques. The method and apparatus of the present invention can be carried out 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 cross-sectional view illustrating an oil mist separator according to a first embodiment.
FIG. 3 is a cross-sectional view showing an oil mist separator according to a second embodiment.
FIG. 4 is a sectional view showing 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 circumferential surface 7 of bearing chamber High-pressure air chamber 8 Swirl 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 Return element tube 57 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 swirling inside a cylindrical bearing chamber containing a bearing that supports a rotating body,
To accelerate the swirling flow in the radially outer position of said bearing chamber by a tunnel-shaped flow rectifier attached to the inner circumferential surface of the bearing chamber, the accelerated the swirling flow in the ribs protruding from the inner peripheral surface of the bearing chamber Spray the oil mist on the ribs ,
The rectifying body takes in a part of the swirl flow from the upstream end in the swirl direction of the swirl flow, and ejects it from the downstream end in the swirl direction of the swirl flow, and from the upstream side in the swirl direction. A method of collecting oil mist, characterized by gradually narrowing the flow path area as it moves downstream in the swirl direction . The oil mist is attached to the surface of the filter by allowing a part of the swirling flow to pass through a filter made of a honeycomb material or a porous material provided in the flow path. How to collect oil mist. An oil mist separator 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,
This was ejected from the downstream end in the turning direction of the swirling flow capture from the upstream end to the internal part of the swirling flow in the swirling direction of the swirling flow, and, downstream of the turning direction from an upstream side of the turning direction A tunnel-like rectifier attached to the inner circumferential surface of the bearing chamber so as to gradually narrow the flow path area as it moves to
Oil mist separator, wherein projecting radially inwardly from the inner peripheral surface of the bearing chamber, the rib swirling flow jetted from the downstream end of the rectifying body blows, in that it consists of. The oil mist separator according to claim 3, wherein a filter made of a honeycomb material or a porous material is attached in a tunnel-like flow path formed by the rectifier.   The oil mist separator according to claim 3 or 4, wherein the rectifying body is formed of a honeycomb material or a porous material.

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