JPH09117625A - Oil recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the oil capturing efficiency by eliminating a pressure loss and a clogging under a comparatively simpler structure and capturing and separating an oil without rescattering a liquid film flowing along the wall of piping. SOLUTION: An air current containing oil mist and an oil film flowing along the wall of piping are guided into an oil capturing chamber 1, and the mist contained in the air current is captured by allowing the mist to collide with a capturing plate 2. In addition, a funnel-like part 5 with a diameter expanded toward the oil capturing plate 2 is formed at an outlet end 3a opposed to the capturing plate 2 of an inlet pipe 3 for guiding the air current containing the mist into the air capturing chamber 1. Thus the oil film is separated and recovered with the oil mist without being rescattered. Further, the efficiency of capturing the micro oil mist is improved by setting a net at the inlet pipe 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil recovery device for separating and removing oil mist, which is a minute oil droplet floating in a gas, and is particularly suitable for use in a blow-by gas reduction system for automobile engines. Regarding

[0002]

2. Description of the Related Art Among various oil mist generated in various industrial processes, oil mist floating in gas such as blow-by gas of an internal combustion engine and oil mist in compressed air of an air drive device, the particle size is about 20 μm or more. The coarse one is a gravity separation device that collects by using natural sedimentation, or an inertial separation device that collects by colliding with a collection plate or the like inserted in a gas flow path by using the inertial force of oil mist ( It can be almost completely separated and removed by an impactor).

Since it is difficult to separate fine oil mist having a particle size of 10 to 20 μm or less by the gravity separating device or the impactor described above, a filter separating device for collecting by a filter or between gas and oil mist is used. A device that causes relative motion to separate the particles, typically a separator that uses centrifugal force (a cyclone) is used. For example, since the oil mist contained in blow-by gas of an automobile engine has a particle size of several μm or less, the above filter or cyclone is generally used for separating and removing such fine oil mist.

However, the blowby gas reduction system (P
As an oil recovery device used for CV), although a filter has a high collection efficiency, it has a major drawback that it cannot maintain stable collection efficiency for a long period of time because it causes clogging. On the other hand, a cyclone has a small pressure loss and is unlikely to cause clogging, but unless a large centrifugal force or a sufficiently long residence time is applied, fine oil mist cannot be separated, and satisfactory collection efficiency cannot be obtained. .

Therefore, conventionally, a baffle plate or a baffle plate is disposed inside the head cover of the engine to provide an oil recovery device which partitions the space into a labyrinth, and blow-by gas is flown therein to collect the oil mist and a large amount. I'm trying to prevent the oil from flowing. Then, the collected oil is supplied to the oil pan, and the blow-by gas that collects the oil mist is returned to the intake system.

[0006]

However, in the conventional oil recovery device, the minute oil mist is not sufficiently removed, and the oil film flowing along the pipe wall is not sufficiently removed. Especially in the PCV of an automobile engine,
The amount of oil film flowing along the blow-by gas along the pipe wall is larger than that of oil mist, so even if part of it can be collected, part of it flows along the wall of the baffle plate and cannot be completely collected. Met.

In addition, the conventional oil recovery device has a large internal volume such as an expansion chamber for reducing the flow velocity of blow-by gas, and the head cover has a large internal volume because the oil recovery device has a large internal volume. There is a problem that the engine height becomes high due to the two-layer structure.

In view of the above circumstances, the present invention has a compact structure that does not require a complicated structure or a large volume, and can be attached to the outside of the engine, is free from pressure loss and clogging, and has an oil mist. An object of the present invention is to provide an oil recovery device that can efficiently collect and separate an oil film flowing along a pipe wall.

[0009]

In order to achieve the above object, an oil recovery apparatus proposed by the present invention introduces an oil mist-containing air flow into a collection chamber together with an oil film transmitted along a pipe wall, and removes the oil mist in the air flow. An oil recovery device that collects the oil film by colliding with the collection plate and collects the oil film together with the oil film, at the outlet end of the inlet pipe that introduces the air flow containing the oil mist into the collection chamber. It is characterized in that a funnel-shaped portion whose diameter increases toward the front side is provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The oil recovery apparatus of the present invention is shown in FIG.
And as shown in FIG. 2, the collecting plate 2 is arranged in the collecting chamber 1,
The oil mist-containing air current is introduced together with the oil film that travels along the tube wall from the inlet tube 3 into the collection chamber 1, and the oil mist in the air current is collected by colliding with the collection plate 2 using the inertial force,
The airflow is exhausted from the outlet pipe 4, and in particular, at the outlet end 3a of the inlet pipe 3 facing the collecting plate 2, a funnel-shaped portion 5 having a funnel-shaped diameter increasing toward the collecting plate 2 is formed. I am doing it.

Preferably, the collection chamber 1 has a cylindrical shape, as shown in FIG.
As shown in FIG. 2, the collecting plate 2 arranged in the collecting chamber 1 is in the shape of a disk, and the collecting plate 2 is composed of a plurality of projecting pieces 2a projecting from the periphery of the collecting plate 2 and the peripheral wall 1a of the collecting chamber 1. It is fixed leaving a gap in. Therefore, the airflow flows between the outer periphery of the collection plate 2 and the peripheral wall 1 a of the collection chamber 1, and flows out of the collection chamber 1 through the outlet pipe 4.

In the oil recovery apparatus of the present invention having such a structure, the oil film formed on the tube wall of the blow-by gas reducing system flows along the tube wall through the inlet pipe 3 of the oil recovery apparatus together with the blow-by gas. Although it enters into the collection chamber 1, the outlet end 3a of the inlet pipe 3 does not have the same diameter as in the conventional case and has a funnel-shaped portion 5 whose diameter increases toward the collection plate 2, so that the oil film is The oil film flows along the inner peripheral surface of the funnel-shaped portion 5 and re-scattering into the airflow can be significantly reduced, and the oil film exits because the tip edge of the funnel-shaped portion 5 is separated from the collecting plate 2. It does not flow into the pipe 4.

The shape of the funnel-shaped portion 5 in the apparatus of the present invention is not particularly limited as long as it has a shape in which the diameter is expanded toward the collecting plate 2 as shown in FIG. 1, but if the diameter is too large, it is too small. However, since the effect of preventing the oil film from re-scattering is lost,
The inner peripheral surface of the funnel-shaped portion 5 is 10 ° with respect to the center line of the inlet pipe.
It is preferable to incline at an angle of -60 °, preferably 25-35 °. Also, the outlet end 3 of the inlet pipe 3
The connection portion between a and the funnel-shaped portion 5 may be appropriately rounded to smoothly change the shape.

The oil film that has moved from the outlet pipe 3 onto the inner peripheral surface of the funnel-shaped portion 5 is radially spread along the inner peripheral surface of the funnel-shaped portion 5 to reduce the flow velocity. As shown in FIG. 5, the oil gradually flows to the lower end along the funnel-shaped inner peripheral surface, and falls along the oil film guide 6 a provided at the lower end of the funnel-shaped portion 5. By inserting the oil film guide 6a of the funnel-shaped part 5 into the drainage port 7 provided at the bottom of the collection chamber 1 as shown in FIG. It can be discharged to the mouth 7.

Therefore, the oil film is almost completely separated and collected,
It will not be re-scattered and partly discharged without being collected. Moreover, since the oil film adsorbs and collects minute oil mist while flowing through the pipe wall, the collection efficiency can be further improved by separating and collecting this oil film without re-scattering as described above. .

Furthermore, in the oil recovery apparatus of the present invention,
By installing a net upstream from the outlet end of the inlet pipe, it is possible to improve the collection efficiency of oil mist,
In particular, it promotes the collection of fine oil mist. This is because a part of the oil film flowing along the pipe wall is a net and a large oil droplet
It is considered that minute oil mist collides with and collects while flowing in the air flow. Most of these large oil droplets settle down before reaching the outlet end due to their own weight to form an oil film, and even if they are discharged from the outlet end, they have a large particle diameter, so they will always collide with the collecting plate and be collected.

If the mesh used is small, the collection rate of oil mist will be good, but the pressure loss will be large. Conversely, if the mesh is large, the pressure loss will be small, but large oil droplets generated from the oil film will be large. The net opening is preferably in the range of 0.2 to 2 mm because it is too small and the amount of generation is small and the collection rate of minute oil mist is lowered. The opening is a numerical value indicating the size of the mesh space. In addition, depending on the inner diameter of the inlet pipe and the flow velocity of the air flow, the location where the net is installed must be at a sufficient distance from the outlet end so that large scattered oil droplets settle in the oil film before reaching the outlet end. is there.

As described above, in the oil recovery apparatus of the present invention, a large amount of oil film is almost completely separated and recovered, and the existence of the oil film allows the fine oil mist in the airflow to flow from the oil film itself to the oil film itself or with a net. Since it is collected in the changed large oil drops, if the oil film and oil drops are prevented from re-scattering and finally separated and collected in the state of the oil film, the overall oil mist collection efficiency is improved. It turns out to get. Therefore, although it has been conventionally required to suppress the formation of an oil film, the presence of the oil film has an advantageous effect on the apparatus of the present invention.

On the other hand, an air stream containing oil mist such as blow-by gas flows toward the collecting plate 2 as shown in FIG. 1, and the oil mist therein collides with the collecting plate 2 and is collected.
The collected oil mists coalesce with each other on the collecting plate 2 and gradually become oil droplets from coarse particles, and flow down from the collecting plate 2 by its own weight. Therefore, by providing the oil film guide 6b at the lower end of the collecting plate 2 and inserting the oil film guide 6b into the drainage port 7, the oil drops flowing down from the collecting plate 2 are completely separated and collected without re-scattering. It

By providing a porous material layer on the surface of the collecting plate 2 facing the inlet pipe 3, a fine oil mist which is difficult to collect with a normal collecting plate, for example, a particle size of 2 μm. The following oil mist collection efficiency can be improved. That is, by adhering to the porous material by entering a minute oil mist that does not normally collide with the collection plate into the porous material layer, gradually aggregate and grow into large oil droplets,
It is re-scattered from the porous material and finally collides with the collecting plate and is collected.

In order for the porous material layer adhered to the collecting plate to fulfill the above-mentioned function, it is necessary that its pressure loss is low. In particular, as the porous material that constitutes the porous material layer, the pressure loss when the porous material layer is arranged on the entire cross section of the collection chamber (without the collection plate) is It is preferably equal to or less than the pressure loss of (without material layer). When the pressure loss of the porous material layer is 1.5 times or less as compared with the case of only the collection plate, the improvement of the collection efficiency is recognized, and particularly when it is equal to or less than the case of only the collection plate. The improvement in efficiency is extremely remarkable.

As the low pressure loss porous material constituting the porous material layer, fiber aggregates made of natural fibers or synthetic fibers, non-woven fabrics, fiber aggregates such as braids; reticulated structures made of metal or ceramics Or a foam body made of plastic such as rubber foam or plastic foam or rubber can be used. Further, the porous material layer can be fixed to the collecting plate by pressing the periphery of the porous material layer with a flange or a collar-shaped frame member or by using an adhesive.

A nozzle for accelerating the oil mist-containing air flow can be provided at the outlet end of the inlet pipe in order to promote the entry and collision of the oil mist into the porous material layer.
The shape of the nozzle may be cylindrical or rectangular. Further, the diameter of the nozzle and the number of nozzles to be installed are not particularly limited, and are appropriately set so that a minute oil mist in the air flow can enter the collection plate into the porous material layer.

[0024]

EXAMPLE As a specific example of the oil recovery apparatus of the present invention,
The apparatus shown in FIG. 3 was prepared. In this device, collection chamber 1
Is a cylinder with an inner diameter of 54 mm and an axial length of 38 mm,
An inlet pipe 3 for the oil mist-containing airflow is provided at the center of the side wall on one side in the axial direction, and an outlet pipe 4 is provided at the center of the side wall on the opposite side. At the outlet end 3a of the inlet pipe 3, there is formed a funnel-shaped portion 5 whose diameter increases toward the outlet pipe 4 side so as to form an angle of 30 ° with the center line of the inlet pipe 3.

Between the inlet pipe 3 and the outlet pipe 4 in the collection chamber 1, a disc-shaped collection plate 2 having a diameter of 48 mm is arranged with its center line aligned with that of the collection chamber 1. It is fixed to the peripheral wall of the collection chamber 1 with a gap left by a plurality of protruding pieces (not shown) protruding from the surroundings. A thickness of 10 mm made of a non-woven fabric of aromatic polyamide fiber (AE-100, manufactured by Nippon Vilene Co., Ltd.) on the surface of the collection plate 2 facing the inlet pipe 3.
The porous material layer 8 is fixed.

The distance between the outlet end 3a of the inlet pipe 3 and the porous material layer 8 on the collecting plate 2 is 22 mm, and the end edge of the funnel-shaped portion 5 provided at the outlet end 3a and the porous material. The tip edge of the funnel-shaped portion 5 was formed obliquely so that the interval between the layers 8 was 8 mm on the upper end side and 2 mm on the lower end side. Further, an oil film guide 6a is provided at the lower end of the funnel-shaped portion 5 and an oil film guide 6b is provided at the lower end of the collecting plate 2, and these thin rod-shaped oil film guides 6a and 6b are both collected at their lower ends. It is inserted into the drainage port 7 of the chamber 1. The drainage port 7 is connected to the tank 10, and the liquid accumulated in the tank 10 is discharged to the outside by a pipe.

As another specific example of the oil recovery device of the present invention, the same device as described above is used, and as shown in FIG. 3, the inlet pipe 3 is provided at a position 50 mm upstream from the outlet end 3a of the inlet pipe 3. An apparatus having a net 9 installed over the entire cross section of No. 3 was also prepared. There were two kinds of nets, a net A having a mesh of 48 and an opening of 357 μm, and a net B having a mesh of 14 and an opening of 1404 μm.

In order to evaluate the collection efficiency of each of the above-mentioned oil recovery devices, the inlet pipe 3 was connected to the oil mist generator 11 and the oil tank 12 as shown in FIG. The oil mist generator 11 is TA
CO Ltd. oil mist generator MicronLube CP
S lubrication unit MC5 was used. Also, the oil tank 1
No. 2 was used for supplying an oil film, and a non-woven fabric 14 was arranged immediately below the valve 13 of the oil tank 12 to change the oil into an oil film, and the oil was transmitted to the inlet wall 3 through the pipe wall.

Using this experimental apparatus, the air flow containing the oil mist and the oil film propagating through the pipe wall were introduced into the collection chamber 1, and the collection efficiency and pressure loss of the oil mist were investigated. The median diameter of the oil mist used was 1.5 μm, the oil mist flow rate was 2435.4 mg / hour, and the oil film flow rate was 700 g /
Time. When supplying only the oil mist, the valve 13 of the oil tank 12 was closed, and the above-mentioned medium diameter oil mist was supplied at the same flow rate as above.

The obtained results are shown for each oil recovery device.
The separation limit particle size of oil mist is shown in Table 1 below.
The collection efficiency and the separation limit particle size were measured with an Andersen air sampler, and the pressure loss was measured with a precision differential pressure gauge. Further, FIG. 4 shows the collection efficiency for each particle size of the oil mist when only the oil mist or both the oil mist and the oil film are supplied to each device.

[0031]

[Table 1] With or without net of oil recovery device Net No net Net A Net B Feed Mist mist + oil film Mist + oil film Mist + oil film Supply mist amount 2435.4 2435.4 2435.4 2435.4 Passing mist amount 1104.2 981.9 658.1 821.0 Collection efficiency (% ) 54.7 59.7 73.0 66.3 Separation limit particle size (μm) 1.9 1.7 1.2 1.4 Pressure loss (mmH ₂ O) 45 45 85 57 (Note) The pressure loss of the filter is the initial value.

As can be seen from the results in Table 1 above, in the apparatus in which the net is not installed in the inlet pipe, the oil mist and the oil film are more collected and collected than the case where only the oil mist is present. However, it is thought that this is because the oil mist is trapped in the oil film. Further, it can be seen that the collection efficiency is further improved by installing the net in the inlet pipe of the same device. However, since the mesh A having a dense mesh has finer oil droplets formed from the oil film, the collection effect is more remarkable, but the pressure loss increases as the mesh becomes denser.

Further, from the results shown in FIG. 4, when the oil film was present together with the oil mist, and when the net was installed, the collection efficiency for each particle size was improved and it was smaller than the case where the net was not provided. It can be seen that even oil mist with various particle sizes can be collected efficiently. This can be understood from the fact that the separation limit particle size shown in Table 1 is particularly small in the apparatus in which the net is arranged.

[0034]

According to the present invention, a pressure loss is achieved by a relatively simple oil recovery device provided with a funnel-shaped portion and an oil film guide together with a collecting plate for collecting oil mist by utilizing inertial collision. There is almost no clogging or clogging, and re-scattering of the oil film that propagates along the pipe wall is prevented, and the oil film can be separated and collected as it is, so there is no decrease in collection efficiency due to re-scattering of the oil film, and the overall oil mist and oil film combined Oil can be efficiently collected.

Moreover, by disposing a net in the inlet pipe to the collection chamber, the oil film can be changed into large oil droplets, and minute oil mist can be collected and returned to the oil film, so that the oil mist can be returned. It is possible to further improve the collection efficiency and thus the oil recovery rate, and at the same time, it is possible to efficiently collect a finer oil mist than in the past.

Further, the oil recovery device of the present invention has a simple structure and high efficiency as described above, and therefore can be miniaturized.
Therefore, it can be installed outside the engine as part of the blow-by gas reduction system of the engine, and the baffle plate and baffle plate inside the head cover are eliminated to reduce the inner volume of the head cover and lower the engine height. The degree of freedom in vehicle exterior design can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a specific example of an oil recovery device of the present invention.

2 is a schematic front view of the oil recovery system of FIG. 1 taken along the line AA. FIG.

FIG. 3 is a schematic cross-sectional view for explaining an experimental device of an oil recovery device of the present invention used in an example.

FIG. 4 is a graph showing the collection efficiency for each oil mist particle size for each oil recovery device in the example.

[Explanation of symbols]

 1 collection chamber 1a peripheral wall 2 collection plate 3 inlet pipe 3a outlet end 4 outlet pipe 5 funnel-shaped parts 6a, 6b oil film guide 7 drainage port 8 porous material layer 9 mesh 10 tank 11 oil mist generator 12 oil tank 13 Valve 14 non-woven fabric

Claims (6)

[Claims] 1. An oil recovery device for guiding an air flow containing oil mist together with an oil film propagating along a pipe wall into a collection chamber, and collecting the oil mist in the air flow by colliding with a collection plate to collect the oil mist together with the oil film. An oil recovery device, characterized in that a funnel-shaped portion whose diameter increases toward the collecting plate is provided at an outlet end of an inlet pipe for introducing an oil mist-containing airflow into the collecting chamber, the outlet end facing the collecting plate. 2. The inner peripheral surface of the funnel-shaped portion at the outlet end of the inlet pipe makes an angle of 10 ° to 60 ° with respect to the center line of the inlet pipe. Oil recovery device. 3. The oil film guide for guiding the oil film to the outside of the collection chamber is provided at the lower end of the funnel-shaped portion and the lower end of the collection plate, respectively. Oil recovery device. 4. The oil recovery device according to claim 1, wherein a net is arranged upstream of the outlet end of the inlet pipe. 5. The opening of the mesh is 0.2-2 mm
The oil recovery device according to claim 4, wherein 6. The surface of the collector plate facing the inlet pipe,
The oil recovery apparatus according to any one of claims 1 to 5, wherein a porous material layer having a low pressure loss is provided.